the education program for the annual congress of the European Hematology Association hematology education education program for the 12th congress of the european hematology association vienna, austria, june 7-10, 2007 the education program for the annual congress of the European Hematology Association hematology education EHA Executive Board E. Hellström-Lindberg, President, Sweden W. Fibbe, President Elect, The Netherlands E. Montserrat, Past President, Spain A. Hagenbeek, Treasurer, The Netherlands I. Roberts, Secretary, United Kingdom EHA Councilors E. Berntorp, Sweden H. Döhner, Germany U. Jäger, Austria C. Lacombe, France C. Mecucci, Italy J. San Miguel, Spain R. Skoda, Switzerland I. Touw, The Netherlands EHA Local Organizing Committee 12th Congress H. Ludwig, Congress President, Austria I. Pabinger, Austria U. Jäger, Austria EHA Scientific Program Committee 12th Congress I. Roberts, Chair, United Kingdom M. Alberich Jorda, USA J. Bladé, Spain N. Casadevall, France H. Döhner, Germany A. Green, United Kingdom C. Mecucci, Italy F. Peyvandi, Italy G. Salles, France N. Zoumbos, Greece EHA Scientific Program Committee Advisory Board 12th Congress P. Beris, Switzerland N. Borregaard, Denmark M. Cavazzana-Calvo, France J. Cools, Belgium N. Cross, United Kingdom T. Enver, United Kingdom A. Falanga, Italy J. Greil, Germany C. Hershko, Israel S. Izraeli, Israel C. Lacombe, France B. Mansouri, Switzerland J. Melo, United Kingdom W. Ouwehand, United Kingdom R. Pieters, The Netherlands A. Rosenwald, Germany B. Schlegelberger, Germany M. Theobald, The Netherlands M. van Oers, The Netherlands W. van Solinge, The Netherlands C. Verfaillie, USA EHA Education Committee A. Green, Chair, United Kingdom E. Berntorp, Sweden C. Chomienne, France C. Craddock, United Kingdom L. Degos, France H. Döhner, Germany E. Hellström-Lindberg, Sweden D. Jasmin, France F. Lo Coco, Italy A. Urbano Ispizua, Spain EHA Publication Commitee M. Cazzola, Editor, Italy R. Foà, Editor, Italy E. Hellström-Lindberg, Sweden C. Lacombe, France S. McCann, Ireland European Hematology Association EHA Executive Office Westblaak 71, 3012 KE, Rotterdam, The Netherlands Tel.: +31 10 436 1760, Fax: +31 10 436 1817 E-mail: [email protected], Website: www.ehaweb.org Word of welcome On behalf of the EHA Education Committee and Scientific Program Committee, we are delighted to welcome you to the beautiful city of Vienna. The EHA Congress is the largest and most comprehensive hematology meeting in Europe with a world class line up of invited speakers. The Education Program covers the whole spectrum of clinical hematology and we have assembled a distinguished cast of internationally-recognised speakers. In addition to enjoying the talks, we hope you find the peer-reviewed papers in the Education Book a useful source of information and references for the coming year. Tony Green Chair Education Committee Irene Roberts Chair Scientific Program Committee Heinz Ludwig Congress President hematology education: the education program for the annual congress of the European Hematology Association - 2007; volume 1, issue 1 Table of Contents Iron Metabolism and Disease 1-8 9-17 18-23 Mechanisms of iron regulation and of iron deficiency C. Hershko, A. Ronson, M. Souroujon, I.Z. Cabantchik, J. Patz Pathophysiology, diagnosis and treatment of the anemia of chronic disease G. Weiss Screening hemochromatosis and iron overload C. Camaschella, A. Pagani, E. Poggiali, L. Silvestri 83-88 Current treatment of T-cell lymphomas: are we making any progress? A. Delmer 89-96 Novel drugs for the treatment of T-cell lymphoma O.A. O’Connor Myeloma 97-101 Advances in myeloma biology: basis for new therapy N. Munshi 102-107 Multiple myeloma: diagnosis, staging and criteria of response J. Bladé 108-114 Novel treatment approaches in multiple myeloma A. Palumbo, I. Avonto, P. Falco, C. Federica, T. Caravita, M.T. Petrucci, M. Cavo, M. Boccadoro, Hemostasis 24-30 Epidemiology of coagulation disorders F. Peyvandi, M. Spreafico 31-38 Recent advances in hemophilia management C. Négrier, Y. Dargaud, J-L. Plantier 39-44 Gene therapy for hemophilia M.K.L. Chuah, T. VandenDriessche Chronic lymphocytic leukemia 115-121 Genetics in chronic lymphocytic leukemia: impact for prognosis and treatment decisions U. Jäger, M. Shehata, D. Heintel, R. Hubmann, B. Kainz, E. Porpaczy, A. Hauswirth, A. Gaiger 122-128 State-of-the-art treatment of chronic lymphocytic leukemia M. Hallek 129-133 New Drugs for chronic lymphocytic leukemia J. Gribben Thrombosis 45-50 Vitamin K epoxide reductase (VKORC1): pharmacogenetics and oral anticoagulation J. Oldenburg, C.R. Müller, M. Watzka 51-55 Do arterial and venous thrombosis share common risk factors? G. Lowe 56-59 Venous thromboembolism in medical patients: stratification and prevention P. Prandoni Hodgkin’s lymphoma 60-63 The role of PET in staging and response assessment L. Specht 64-69 Tailoring the treatment for early-stage Hodgkin’s lymphoma M. André, O. Reman 70-75 Treatment of relapsing/refractory patients with Hodgkin lymphoma P. Brice What’s new in T-cell non-Hodgkin’s lymphomas? 76-82 Pathology and genetics of T-cell lymphomas A. Chott, A-I. Schmatz, E. Kretschmer-Chott, L. Müllauer, B. Streubel Sickle cell disease 134-139 Hemolysis-associated pulmonary hypertension in sickle cell disease and thalassemia G.J. Kato, M.T. Gladwin 140-147 The contribution of asthma to sickle cell disease related morbidity and mortality M.R. DeBaun, J.E. Jennings, J.H. Boyd, J.J. Field, C. Hiller, R.C. Strunk 148-153 Hydroxyurea: benefits and risks in patients affected with sickle cell anemia M. De Montalembert Acute lymphoblastic leukemia 154-160 Genetics of T-cell acute lymphoblastic leukemia C.J. Harrison 161-167 Treatment of Philadelphia chromosome positive acute lymphoblastic leukemia O.G. Ottmann, H. Pfeifer, B. Wassmann education program for the 12th congress of the european hematology association, vienna, austria, june 7-10, 2007 hematology education: the education program for the annual congress of the European Hematology Association - 2007; volume 1, issue 1 Table of Contents 168-174 Detection of minimal residual disease in adult patients with acute lymphoblastic leukemia: methodological advances and clinical significance M. Brüggemann, T. Raff, S. Böttcher, S. Irmer, S. Lüschen C. Pott, M. Ritgen, N. Gökbuget, D. Hoelzer, M. Kneba Acute myeloid leukemia 175-182 Targeting critical pathways in leukemia stem cells S. Anand, W-I. Chan, B.T. Kvinlaug, B.J.P. Huntly 183-192 Clinical use of molecular markers in adult acute myeloid leukemia K. Mrózek, P. Paschka, G. Marcucci, S.P. Whitman, C.D. Bloomfield 193-199 Management of elderly patients with acute myeloid leukemia H. Dombret, E. Raffoux, L. Degos 254-258 Conventional and new treatment modalities for myelofibrosis F. Cervantes Cellular immunotherapy and vaccination 259-264 The molecular and cellular basis for immunotherapeutic intervention in malignant disease: dynamic imaging of the immune system C. Lotz 265-269 Immunotherapy of leukaemia with TCR gene modified T cells E.C. Morris, D.P. Hart, J. King, S. Thomas, M. Cesco-Gaspere, S. Xue, H.J. Stauss 270-277 Perspectives and limitations of vaccination strategies against cancer P. Romero, D. Speiser Myelodysplastic syndromes Transfusion - Diagnosis and management of alloimmune thrombocytopenia 200-204 Molecular pathogenesis of myelodysplastic syndromes C.M. Niemeyer, C.P. Kratz 278-284 Human platelet alloantigens: heterogeneity of platelet alloantibodies I. Soche, T. Bakchoul, S. Santoso 205-214 Epigenetic therapy in myelodysplastic syndromes P. Fenaux, C. Gardin 285-293 215-218 New developments in curative approaches in myelodysplasia T. de Witte, R. Brand, A. van Biezen, S. Suciu, L. Baila, P. Muus, M. Schaap, A. Schattenberg, R. Martino, N. Kröger, S. Amadori Laboratory diagnosis of neonatal alloimmune thrombocytopenia L. Porcelijn 294-298 Treatment and prevention of alloimmune thrombocytopenias A. Husebekk, M. Kjær Killie, J. Kjeldsen-Kragh, B. Skogen Chronic myeloid leukemia New and evolving techniques in diagnostic hematology 219-225 Clinical implications of ABL mutational screening N. von Bubnoff, J. Duyster 299-305 226-230 Decision making at diagnosis in chronic myeloid leukemia M. Baccarani, F. Palandri, F. Castagnetti, A. Pusiol Genome-wide approaches to identify new subtypes of acute myeloid leukemia P. Valk 306-310 231-239 Management of patients with imatinib resistance E. Olavarria, J.F. Apperley Which new tests should be offered by clinical haemostasis laboratories? M. Greaves, H.G. Watson 311-315 The role of molecular analysis in investigation of inherited anemias A. Iolascon, L. Boschetto, L. De Falco, S. Scianguetta, R. Russo, C. Piscopo, I. Andolfo a Index of authors Myeloproliferative disorders 240-247 Molecular pathogenesis of the myeloproliferative diseases W. Vainchenker, F. Delhommeau, J-L. Villeval 248-253 Diagnosis and classification of myeloproliferative disorders in the JAK2 era C. Harrison education program for the 12th congress of the european hematology association, vienna, austria, june 7-10, 2007 Iron Metabolism and Disease Mechanisms of iron regulation and of iron deficiency C. Hershko1,2 A. Ronson1,3 M. Souroujon2 I.Z. Cabantchik4 J. Patz3 1 Department of Hematology, Shaare Zedek Medical Center, 2 Hematology Clinic and Central Clinical Laboratories , Clalit Health Services 3 Hematology and Gastroenterology Clinics, Meuhedet Health Services 4 Department of Biological Chemistry, Institute of Life Sciences, Hebrew University of Jerusalem, Israel Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:1-8 A B S T R A C T Basal cellular iron handling in enterocytes is performed by the interaction of ferric reductase, two distinct transport proteins for ferrous iron located on the duodenal brush border (DMT1) and the basolateral membrane (ferroportin 1) respectively, and ferroxidase facilitating iron egress. The fine tuning of iron regulation and its adaptation to body iron requirements is performed by hepcidin. Increased levels of serum diferric transferrin activate an iron sensor and signal transduction effector complex, consisting of TFR2, HFE and HJV for downstream regulation of hepcidin production. Despite these elegant regulatory mechanisms, iron deficiency remains one of the the most common nutritional deficiencies of mankind. Physiological or nutritional iron deficiency is the result of an interplay of increased host requirements, limited external supply, and increased blood loss. By contrast, pathological iron deficiency is most often the result of gastrointestinal disease associated with abnormal blood loss or malabsorption. If gastroenterologic evaluation fails to disclose a likely cause of IDA, or in patients refractory to oral iron treatment, screening for celiac disease, autoimmune gastritis, and H pylori is recommended. Recent studies indicate that 20 to 27% of patients with unexplained IDA have autoimmune gastritis, about 50% have evidence of active H pylori infection, and 4 to 6% have celiac disease. The implications for abnormal iron absorption of celiac disease or autoimmune gastritis are obvious. In patients with unexplained IDA and H pylori infection, refractoriness to oral iron treatment would justify a therapeutic trial of H pylori eradication. Stratification by age cohorts in autoimmune gastritis implies a disease presenting as IDA many years before the establishment of clinical cobalamin deficiency. It is caused by an autoimmune process likely triggered by antigenic mimicry between H pylori epitopes and major autoantigens of the gastric mucosa. Recognition of the respective roles of H pylori and autoimmune gastritis in the pathogenesis of iron deficiency may have a strong impact on the diagnostic workup and management of unexplained, or refractory iron deficiency anemia. s a transition metal, iron plays an essential role in life by its ability to accept and donate electrons. Some of the most important functions of iron proteins are oxygen transport, mitochondrial oxidative energy production, inactivation of drugs and toxins, and DNA synthesis. The solubility of iron in its stable, oxidised form is extremely low and, although iron is one of the most abundant elements in nature paradoxically, iron deficiency is one of the most common nutritional problems of the human race.1 Consequently, evolution has provided efficient mechanisms of iron acquisition and storage but no mechanisms at all for excreting excess iron. A Mechanisms of iron regulation Basic regulation In order to gain access to the duodenal enterocyte (Figure 1) ferric iron in the intestinal lumen is first reduced to ferrous iron by duodenal cytochrome b reductase 1 (DCYTB)2 and subsequently transported through the duodenal brush border membrane by divalent metal transporter 1 (DMT1), a proton transporter requiring low pH for efficient functioning.3,4 Heme iron is transported by a different mechanism5 by heme carrier protein 1 (HCP1) and is subsequently split by heme oxygenase to mix with the pool of intracellular iron. The intracellular transport of lowmolecular iron in the enterocyte is not well characterized. In principle, it can be utilized for the de novo production of functional iron proteins, stored in ferritin, or exported through the basolateral membrane of the enterocyte. Iron stored in enterocyte ferritin has a low turnover rate and is lost by sloughing of intestinal enterocytes within a few days. Iron export through the basolateral membrane is performed by the basolateral iron transport protein ferroportin 1 (FPN, IREG1).6,7 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 1 | 12th Congress of the European Hematology Association Brush border Fe(III) Basolater DM T1 Fe reductase Fe(II) Fe(II) Fe(II) Fe(III) Fe(II) Fe(II) Fe(II) Labile Iron Pool Fe(II) Ferroportin Hephaestin Fe(II) HCP 1 Fe(III) Fe(III) Fe(III) ferritin Fe(II) Fe(II) Fe(III) Fe(II) Tf Fe heme Fe(II) Fe(III) endocytic vesicle TfR Fe(III) Tf Fe(III) Fe(III) Fe(III) Figure 1. Ferric iron in the intestinal lumen is first reduced to ferrous iron by duodenal cytochrome b2 (Fe reductase) and subsequently transported through the duodenal brush border membrane by divalent metal transporter 1 (DMT1).3,4 Heme iron is transported by heme carrier protein 1 (HCP1)5 and is subsequently split by heme oxygenase to mix with the pool of intracellular iron. The intracellular transport of low-molecular iron in the enrterocyte is not well characterized. Iron stored in enterocyte ferritin has a low turnover rate and is lost by sloughing of intestinal enterocytes within a few days. Iron export through the basolateral membrane is performed by the basolateral iron transport protein ferroportin (FPN, IREG1).6,7 Following its transport, ferrous iron has to be oxidized in order to bind to circulating transferrin. This function is performed by ceruloplasmin, a circulating multicopper oxidase, or hephaestin, a cellular homolog of ceruloplasmin.8,9 Diferric transferrin is internalized after binding to transferrin receptor TfR-1, and following acidification and reduction crosses the vesicular membrane via the DMT1 transporter Ferroportin is essential for the basolateral transport of iron from enterocytes, for placental iron transfer and, for exporting the catabolic iron derived from senescent erythrocytes from tissue macrophages. Similar to DMT1, the export of iron by ferroportin is in the reduced ferrous form. However following its transport, iron has to be oxidized in order to bind to circulating transferrin. This function is performed by ceruloplasmin, a circulating multicopper oxidase, or hephaestin, a cellular homolog of ceruloplasmin.8,9 The oxidation of ferrous iron outside the basolateral membrane creates a concentration gradient of ferrous iron across the cell membrane, facilitating its egress from the cell. The above description of iron tranport based on the interaction of a ferric reductase, two distinct transport proteins for ferrous iron located on the duodenal brush border and the basolateral membrane respectively and ferroxidase facilitating iron egress, may explain basal iron handling but offers no explanation for the adaptation of iron handling to variable physiologic needs . Milestones in hepcidin discovery The discovery of hepcidin and its role in iron homeostasis represents a major advance in understanding iron regulation. The saga of hepcidin discovery is summarized in Table 1. The intensity of Table 1. Milestones in the hepcidin saga. Krause A et al.10 FEBS Letters Sept 1 2000 LEAP-1 (liver expressed antimicrobial peptide) a 25 residue peptide containing 4 disulfide bonds: identified by mass spectrometric assay in human plasma Park CH et al.11 JBC Epub Dec 11 2000 Hepcidin a urinary antimicrobial peptide synthesized in the liver: 20 and 25 amino-acid residues with 8 cysteines connected by disulfide bonds Pigeon C et al.12 J Biol Chem Epub Dec 11 2000 Identification of a 83 amino acid protein with strong homology to human hepcidin by suppressive subtractive hybridization between iron-loaded and normal mice implying a role in iron overload distinct from antim icrobial activity Nicolas G et al.13 PNAS Epub Jul 10 2001 Lack of hepcidin gene expression in upstream stimulatory factor 2 (USF 2) knockout mice results in severe tissue iron overload Nicolas G et al.14 PNAS Apr 2 2002 Over expression of liver hepcidin in transgenic mice results in severe iron deficiency anemia Roetto et al.15 Nat Genet Epub Dec 9 2002 First identification of human hepcidin mutations in 2 families with juvenile hemochromatosis Nemeth et al.16 Science Epub Oct 28 2004 Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization research performed in this field is illustrated by the rapid sequence of observations as shown by the dates of their publication. Liver expressed antimicrobial peptide (LEAP-1), a 25 residue peptide containing 4 disulfide bonds was identified by mass spectrometric assay in human plasma, and first described by Krause et al. in September 1 2000.10 These authors considered their discovery as an extention of the known families of mammalian peptides with antimicrobial activity, characterized by a unique disulfide motif and distinct expression pattern.10 A few months later, 2 studies were published back-to-back in the Journal of Biological Chemistry.11,12 Park et al.11 described hepcidin, a urinary antimicrobial peptide synthesized in the liver consisting of 20 and 25 amino-acid residues (practically identical with LEAP1) with 8 cysteines connected by disulfide bonds. The liver was the predominant site of mRNA expression and the encoded propeptide contained 84 amino acids. Simultaneously, in a search for abnormally expressed hepatic genes under conditions of iron excess, employing suppressive subtractive hybridization between iron-loaded and normal mice, Pigeon et al.12 described the overexpression of a 83 amino acid protein with strong homology to human hepcidin controlled by a gene located in close proximity to the upstream stimulatory factor 2 (USF2) gene. Pigeon et al also recognized that hepcidin expression is | 2 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 enhanced under the effect of lipopolysaccharide, a known inducer of inflammatory response. They correctly concluded that these observation imply a role of hepcidin in iron overload distinct from its antimicrobial activity. These landmark studies were reinforced and extended by the report that fortuitous inactivation of the hepcidin gene in USF2 knockout mice results in severe tissue iron overload identical in phenotype with HFE knockout mice suggesting that hepcidin may function in the same regulatory pathway as HFE.13 The same group has also shown that over- expression of liver hepcidin in transgenic mice results in severe iron deficiency anemia.14 That hepcidin mutations are responsible for severe (juvenile) hereditary hemochromatosis in humans was first described in 2002 by Roetto et al.15 Finally, the mechanism of hepcidin interference with cellular iron transport at two main sites, tissue macrophages and the intestinal epithelium, by its binding to ferroportin resulting is its internalization and degradation was disovered by Nemeth et al., in 2004.16 Rate of hepcidin response In vivo observations in humans and experimental animals indicate that hepcidin expression is increased in response to serum iron, iron overload and inflammation, and is suppressed by iron deficiency, hypoxia and increased erythropoietic activity.17,18 The hepcidin response is remarkably rapid. In man, iron ingestion at a dose of 65 mg/d results in a sharp increase of urinary hepcidin excretion within 24 hours of starting treatment.19 Likewise, infusion of recombinant IL-6, a known mediator of hepcidin response in inflammation, results in significant increase in urinary hepcidin, decreased serum iron and transferrin saturation within 2 hours of infusion.19 These observations imply that hepcidin expression is directly controlled by serum iron and IL-6 and not through a long-term gradual accumulation of iron in tissues. Control of hepcidin response The regulation of hepcidin expression is transcriptional. Two signal transduction patways modulate the binding of transcription factors to the hepcidin promoter: Under basal conditions, hepcidin expression depends upon signalling through the bone morphogenetic protein BMP/SMAD pathway.20,21 Hemojuvelin participates in this patway as a BMP coreceptor. The second type of transcriptional hepcidin regulation occurs in inflammation: Here interleukin 6 IL-6 induces transcription of the hepcidin gene by activating signal transducer and activator of transcription 3 (STAT3) and its binding to a regulatory element in the hepcidin promoter.22 Mutations of five unrelated genes are know to result in genetic hemochromatosis in man:23 the classic hereditary hemochromatosis HFE, transferrin receptor 2 TFR-2, the iron transporter ferroportin FPN1, hemojuvelin HJV and hepcidin HAMP. All forms of genetic hemochromatosis are characterized by decreased hepcidin production or activity. Since HFE, TFR-2 and HJV are all expressed on the surface of hepatocytes, it was reasonable to expect that they all may participate in the control of hepcidin expression. Recent studies have indeed confirmed the existence of such a mechanism.24,25 It is based on the competition of transferrin receptor 1 (TFR-1) and TFR-2 for binding the HFE protein. During low or basal serum iron conditions, HFE and TFR-1 exist as a complex at the plasma membrane and TFR-1 serves to sequester HFE to silence its activity. Diferric serum transferrin (Fe2-TF) competes with HFE for the binding of TFR-1. Increased serum transferrin saturation results in the dissociation of HFE from TFR-1. Acting as an iron sensor, HFE then binds TFR-2 and thus conveys the Fe2-TF status to an iron sensor and signal transduction effector complex consisting of TFR-2, HFE and HJV for downstream transduction of hepcidin production. These elegant studies imply that diferric transferrin is the physiologic regulator of hepcidin and support the implications of clinical observations in short term oral iron administration that hepcidin expression is directly controlled by serum iron and not by the long-term gradual accumulation of iron in tissues.19 However, the decreased hepcidin expression associated with accelerated erythropiesis and the role of the putative erythroid regulator in iron homeostasis remain at present unexplained.26 Mechanisms of iron deficiency Despite the carefully orchestrated mechanism of normal iron homeostasis, iron deficiency is still a major health problem. Its development is the result of an interplay between three distinct risk factors: increased host requirements, limited external supply, and increased blood loss. Iron deficiency is associated with serious health risks including abnormal mental and motor development in infancy; impaired work capacity; increased risk of premature delivery; and increased maternal and infant mortality in severe anemia.1 Increased requirements are the outcome of increased physiologic needs associated with normal development. This category of iron deficiency is often designated physiologic, or nutritional. Increased physiologic needs are associated with periods of life characterized by accelerated growth rates such as early infancy, adolescence and pregnancy. In healthy females normal menstruation represents an additional physiologic burden.27 Although Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 3 | 12th Congress of the European Hematology Association Table 2. Main diagnostic categories and coexistent findings in 300 IDA patients referred for hematologic evaluation. Diagnosis (N) Autoimmune atrophic gastritis (77) 26% H. pylori* (57) 19% Menorrhagia (96) 32% Gastrointestinal lesions (31) 10% Celiac (18) 6% Negative (21) 7% Age 41±16 37±19 39±10 60±14 39±14 33±13 Gender M/F 14/63 17/40 0/96 13/18 3/15 2/21 Main diagnosis alone 26 57 39 21 15 21 H.pilory 39 – 57 10 2 0 Menorrhagia 11 0 – 0 1 0 Gastrointestinal lesions 1 0 0 – 0 0 Aspirin or NSAID 9 3 1 7 0 1 69% 68% 38% 47% 100% 10% % Refractory to oral iron *165 total H pylori. Use of aspirin or NSAID is listed as additional information but is not counted separately in the total number of subjects. Under the heading celiac are also included 4 patients with gastroplasty. normal gastrointestinal iron absorption is regulated by effective mechanisms adapting for increased requirements by enhanced absorption, the magnitude of iron absorption is limited by caloric intake and the quality of food. These, in turn, are often determined by socioeconomic conditions. The prevalence of iron deficiency and iron deficiency anemia in the world is a reflection of the interaction of these variables. Unfavorable socioeconomic conditions are associated as a rule with a high prevalence of iron deficiency and the major victims are infants and fertile women i.e. those with the highest physiologic needs.27 This dismal global situation has not shown any indication of improvement over recent years. Nevertheless, successful targeted food fortification programs among high risk subpopulations demonstrate28-30 that, major improvements are possible if resources are available in collaboration with local health authorities or the food industry. By contrast, pathologic iron deficiency is most often the result of gastrointestinal disease associated with abnormal blood loss or malabsorption. Consequently, in grown males and post-menopausal females, complete gastroenterologic investigation is recommended to identify pathological lesions responsible for abnormal blood loss. However, conventional endoscopic and radiographic methods fail to identify a probable source of gastrointestinal blood loss in about one third of males and post-menopausal females and in most young women with iron deficiency anemia.31-33 Obscure or refractory iron deficiency In recent years, there is an increasing awareness of subtle, non-bleeding gastrointestinal conditions that may result in abnormal iron absorption leading to IDA in the absence of gastrointestinal symptoms. Thus, the importance of celiac disease as a possible cause of IDA refractory to oral iron treatment, without other apparent manifestations of malabsorption syndrome34 is increasingly recognized. In addition, Helicobacter pylori has been implicated in several recent studies as a cause of IDA refractory to oral iron treatment, with a favorable response to H pylori eradication.35,36 Likewise, autoimmune atrophic gastritis, a condition associated with chronic idiopathic iron deficiency, has been shown to be responsible for refractory IDA in over 20% of patients with no evidence of gastrointestinal blood loss.37,38 The recent availability of convenient, non-invasive screening methods for identifying celiac disease (endomysial, and gliadin antibodies) autoimmune atrophic gastritis (serum gastrin, parietal cell antibodies) and H pylori infection (antibody screening and urease breath test) greatly facilitated the recognition of patients with these entities, resulting in an increased awareness of these conditions and their possible role in the causation of IDA. In a prospective study, we have screened 300 consecutive IDA patients referred to a hematology outpatient clinic, employing the above methods for identifying non-bleeding GI conditions including celiac disease , autoimmune atrophic gastritis and H pylori gastritis (Table 2) The mean age of all subjects was 39±18 y, and 251 of the 300 (84%) were women of reproductive age. We identified 18 new cases of adult celiac disease (6%). Seventy-seven IDA patients (26%) had autoimmune atrophic gastritis of whom 39 (51%) had coexistent H pylori infection. H pylori infection was the only finding in 57 patients (19%), but was a common coexisting finding in 165 (55%) of the entire group. Refractoriness to oral iron treatment was | 4 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 found in 100% of patients with celiac disease, 69% with autoimmune atrophic gastritis, 68% with H pylori infection, but only 10% of subjects with no underlying abnormality. In the following we wish to discuss the implications of the above findings to the pathogenesis and management of unexplained iron deficiency anemia. Autoimmune atrophic gastritis The concept of gastric atrophy as a cause of iron deficiency anemia is not new. Achylia gastrica associated with iron deficiency anemia has been described as a clinical entity by Faber as early as 1909 39 and achlorhydric gastric atrophy, a synonym for the same entity, has long been recognized as a major cause of iron deficiency anemia40 but largely forgotten, and completely ignored in subsequent major surveys of gastrointestinal causes of iron deficiency anemia. More recently, achlorhydric gastric atrophy has been rediscovered by Dickey et al.,38 and implicated in 20% of iron deficiency anemia patients with no evidence of gastrointestinal blood loss. This observation was confirmed and greatly extended in a series of important studies by Annibale et al 37 who found 27% of patients with refractory iron deficiency anemia without gastrointestinal symptoms to have atrophic body gastritis , a percentage identical with the proportion of subjects with autoimmune atrophic body gastritis found in our previous 41 and present studies. Impaired iron absorption in pernicious anemia is corrected by normal, but not by neutralized gastric juice, indicating that lack of gastric acidity is the key factor in abnormal iron absorption.42 Other studies have also shown that iron absorption is heavily dependent on normal gastric secretion and acidity for solubilizing and reducing dietary iron.43,44 Although atrophic gastritis may impair both B12 and iron absorption simultaneously, in young women in whom menstruation represents an added strain on iron requirements, iron deficiency will develop many years before the depletion of vitamin B12 stores. It is, however, the crucial development of anti-intrinsic factor antibodies with subsequent loss of the remaining gastric intrinsic factor that determines the prevalence of pernicious anemia. Helicobacter pylori gastritis The role of H pylori in the causation of IDA is at present unsettled as H pylori infection is very common in the normal population. Major population surveys involving thousands of subjects45 conducted over diverse geographic areas all indicate that H pylori positivity is associated with a slight and significant decrease in serum ferritin levels implying diminished iron stores, but there was no evidence of a high prevalence of iron deficiency anemia associated with H pylori seropositivity in the populations at large. Nevertheless, in a subset of patients, a cause-andeffect relation between H pylori and serious gastrointestinal pathology including duodenal ulcer, atrophy of the gastric body predisposing to gastric ulcer and cancer, or the formation of mucosa-associated lymphoid tissue (MALT) lymphoma has been established and strongly supported by the beneficial effects of H pylori eradication in these conditions.46 Consequently, in a search of evidence for a cause-and-effect relation between H pylori and IDA, it could be more rewarding to focus on the possible beneficial effects of H pylori eradication on refractory IDA. Our previous observations, indicating that failure to respond to oral iron treatment in H pylori positive patients was more than twice as common as in the H pylori negative group, and that successful H pylori eradication resulted in an increase in hemoglobin levels indistinguishable form that in previously responsive IDA patients,41 are in agreement with a number of previous studies.36,47,48 Most of these reports involved young females refractory to oral iron treatment, and improvement has been observed following H pylori eradication even in the absence of continued iron administration . Because menstrual blood loss is a serious compounding factor in evaluating alternative causes of IDA, in a recent study we have focussed on 29 male IDA patients with negative gastorintestinal workup distinguished by their poor initial response to oral iron treatment, and high prevalence of H pylori infection (25 of 29) with (10) or without (15) coexistent autoimmune gastritis.49 Following H pylori eradication, all patients achieved normal hemoglobin levels with follow-up periods ranging from 4 to 69 months (38±15 months mean± 1SD). This was accompanied by a significant decrease in H pylori IgG antibodies and in serum gastrin levels. Sixteen patients discontinued iron treatment, maintaining normal hemoglobin and ferritin and may be considered cured. Remarkably, 4 of the 16 achieved normal hemoglobin without ever having received oral iron after H pylori eradication. A number of possible mechanisms have been invoked to explain the relation between H pylori gastritis and IDA including occult gastrointestinal bleeding and competition for dietary iron by the bacteria . However, the most likely explanation is the effect of H pylori on the composition of gastric juice. Studies by Annibale and others50 have shown that gastric acidity and ascorbate content, both of which are critical for normal iron absorption, are adversely effected by H pylori infection and, that H pylori eradication results in normalization of intragastric pH and ascorbate content. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 5 | 12th Congress of the European Hematology Association B2 pg/mL; Gastrin; U/mL; H. pylory % positive 1000 900 800 700 600 500 400 300 200 100 0 <20y 21-40y 41-60y >61y B12 gastrin Hp/1000 Figure 2. Effect of age on autoimmune gastritis: Stratification by age cohorts of autoimmune gastritis from <20 to >60 y showed a prevalence of coexistant H pylori infection of 87.5% at age <20 y, 47% at 20-40 y, 37.5 % at 41-60 y and 12.5% at age > 60y. With ages increasing from <20 to >60 y, there was a regular and progressive increase in gastrin from 349±247 to 800±627 u/mL , and a decrease in cobalamin from 392±179 to 108±65 pg/mL. Possible role of H pylori in the pathogenesis of autoimmune gastritis In order to define the relation between IDA associated with autoimmune gastritis and pernicious anemia, we have studied 160 patients with autoimmune gastritis of whom 83 presented with IDA, 48 with autoimmune gastritis and normocytic indices, and 29 with macrocytic anemia.51 Stratification by age cohorts of autoimmune gastritis from <20 to >60 y showed a prevalence of coexistant H pylori infection of 87.5% at age <20 y, 47% at 20-40 y, 37.5 % at 4160 y and 12.5% at age > 60y. With ages increasing from <20 to >60 y, there was a regular and progressive increase in MCV from 68±9 to 95±16 fl, serum ferritin from 4±2 to 37±41 µg/L, gastrin from 349±247 to 800±627 u/mL , and a decrease in cobalamin from 392±179 to 108±65 pg/mL (Figure 2). The high prevalence of H pylori positivity in young patients with autoimmune gastritis and its almost total absence in elderly patients with pernicious anemia implies that H pylori infection in autoimmune gastritis may represent an early phase of disease in which an infectious process is gradually replaced by an autoimmune disease terminating in burned-out infection and the irreversible destruction of gastric body mucosa. Although this question has long intrigued investigators, the relation between H pylori and the pathogenesis of pernicious anemia is still unsettled.52 H pylori-infected subjects have circulat- Figure 3. Proposed diagnostic workup of IDA in patients with negative GI studies and in patients refractory to oral iron treatment, involving non-invasive screening for celiac disease (anti-endomysial antibodies) autoimmune type A atrophic gastritis (gastrin, antiparietal antibodies) and H pylori (IgG antibodies followed by urease breath test). ing IgG antibodies directed against epitopes on gastric mucosal cells. Of these, the most likely target of an autoimmune mechanism triggered by H pylori and directed against gastric parietal cells by means of antigenic mimicry53-60 is H+K+-ATPase, a protein that is the most common autoantigen in pernicious anemia. Conversely, H pylori eradication in patients with autoimmune atrophic gastritis is followed by improved gastric acid and ascorbate secretion in many, and complete remission of atrophic gastritis in a variable proportion of patients.61-63 Failure to achieve complete remission by H pylori eradication in the majority of patients does not necessarily argue against the role of H pylori in the pathogenesis of autoimmune gastritis but, more likely indicates that a point of no-return may be reached beyond which the autoimmune process may no longer require the continued presence of the inducing pathogen. Recommendations for the diagnostic workup of refractory or obscure IDA In view of the above considerations, a rapid screening for celiac disease (anti-endomysial antibodies) autoimmune type A atrophic gastritis (gastrin, antiparietal antibodies) and H pylori (IgG antibodies followed by urease breath test) may provide a highsensitivity screening and an effective starting point for further investigations . This is particularly recommended in all patients with obscure IDA and in those refractory to oral iron treatment (Figure 3). The implications of diagnosing celiac disease or autoimmune atrophic gastritis for abnormal iron absorption are obvious. Interpretation of positive serology for H pylori confirmed by positive urease breath test requires clinical judgment as 20 to 50% of the general and largely healthy population in industrialized | 6 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 countries will have such findings. In such patients, refractoriness to oral iron treatment may justify a testand-treat approach of H pylori eradication as currently advocated for the management of dyspeptic patients.64 Cure of previously refractory IDA by H pylori eradication could then be regarded as evidence supporting a. cause-and-effect relation. 24. 25. 26. 27. References 1. Cook JD, Skikne BS, Baynes RD. Iron deficiency: the global perspective. Adv Exp Med Biol 1994;356: 219-28. 2. McKie AT, Barrow D, Latunde-Dada GO, et al. An iron-regulated ferric reductase associated with the absorption of dietary iron. Science 2001;291:1755-59. 3. Fleming MD, Trenor CC, Su MA, et al. Microcytic anaemia mice have a mutation in Nramp2, a candidate iron transporter gene. Nat Genet 1997;16:383-6. 4. Gunshin H, Mackenzie B, Berger UV, et al. Cloning and characterization of a mammalian proton-coupled metal-ion transporter. Nature 1997;388:482-8. 5. Shayeghi M, Lattunde-Dada GO, Oakhill JS, et al. Identification of an intestinal heme transporter. Cell 2005;122:789801. 6. McKie AT, Marciani P, Rolfs A, et al. A novel duodenal ironregulated transporter, IREG1, implicated in the basolateral transfer of iron to the circulation. Mol Cell 2000;5:299-309. 7. Donovan A, Lima CA, Pinkus JL, et al. The iron exporter ferroportin/Slc40a1 is essential for iron homeostasis. Cell Metab 2005;1:191-200. 8. Harris ZL, Durley AP, Man TK, et al. Targeted gene disruption reveals an essential role for ceruloplasmin in cellular iron efflux. Proc Natl Acad Sci USA 1999;96:10812-7. 9. Vulpe CD, Kuo YM, Murphy TL et al. Hephaestin, a ceruloplasmin homologue implicated in intestinal iron transport, is defective in the sla mouse. Nat Genet 1999;21:195-9. 10. Krause A, Neitz S, Magert, HJ, et al. LEAP-1, a novel highly disulfide-bonded human peptide, exhibits antimicrobial activity. FEBS Lett 2000;480:147-50. 11. Park CH, Valore EV, Waring AJ, et al. Hepcidin, a urinary antimicrobial peptide synthesized in the liver. J Biol Chem 2001;276:7806-10. 12. Pigeon C, Ilyin G, Courseaud B, et al. A new mouse liver-specific gene, encoding a protein homologous to human antimicrobial peptide hepcidin, is overexpressed during iron overload. J Biol Chem 2001;276:7811-9. 13. Nicolas G, Bennoun M, Devaux I. Lack of hepcidin gene expression and severe tissue iron overload in upstream stimulatory factor 2 (USF2) knockout mice. Proc Natl Acad Sci USA 2001;98: 8780-5. 14. Nicolas G, Bennoun M, Porteu A. Severe iron deficiency anemia in transgenic mice expressing liver hepcidin. Proc Natl Acad Sci USA 2002;99:4596-601. 15. Roetto A, Papanikolaou G, Politou M, et al. Mutant antimicrobial peptide hepcidin is associated with severe juvenile hemochromatosis. Nat Genet 2003;33:21-2. 16. Nemeth E, Tuttle MS, Powelson J, et al. Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization. Science 2004;306:2090-3. 17. Andrews NC, Schmidt PJ Iron homeostasis. Annu Rev Physiol 2007;69:16.1-16.17 18. Nicolas G, Chauvet C, Viatte L, et al. The gene encoding the iron regulatory peptide hepcidin is regulated by anemia, hypoxia, and inflammation. J Clin Invest 2002;110:1037-44. 19. Nemeth E, Rivera S, Gabayan V, et al. IL-6 mediates hypoferremia of inflammation by inducing the synthesis of the iron regulatory hormone hepcidin. J Clin Invest 2004;113:1271-6. 20. Babitt JL, Huang FW, Wrighting DM, et al. Bone morphogenetic protein signaling by hemojuvelin regulates hepcidin expression. Nat Genet 2006;38:531-9. 21. Truksa J, Peng H, Lee P, Beutler E. Bone morphogenetic proteins 2, 4, and 9 stimulate murine hepcidin 1 expression independently of Hfe, transferrin receptor 2 (Tfr2), and IL-6. Proc Natl Acad Sci USA 2006;103:10289-93. 22. Wrighting DM, Andrews NC. Interleukin-6 induces hepcidin expression through STAT3. Blood 2006;108:3204-9. 23. Camaschella C. Understanding iron homeostasis through 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. genetic analysis of hemochromatosis and related disorders. Blood 2005;106:3710-7. Goswami T, Andrews NC. Hereditary hemochromatosis protein, HFE, interaction with transferrin receptor 2 suggests a molecular mechanism for mammalian iron sensing. J Biol Chem 2006; 281:28494-8. Schmidt PJ, Huang FW, Wrighting DM, et al. Hepcidin expression is regulated by a complex of hemochromatosis-associated proteins. Blood 2006;83a, ASH Annual Meetings Abstract # 267. Pak M, Lopez MA, Gabayan V. Suppression of hepcidin during anemia requires erythropoietic activity. Blood 2006;108: 3730-5. Stoltzfus RJ. Iron-deficiency anemia: reexamining the nature and magnitude of the public health problem. J Nutrition 2001;131: 697S-701S. Thuy PV, Berger J, Davidsson L, Khan NC, Lam, NT, Cook JD, et al. Regular consumption of NaFeEDTA-fortified fish sauce improves iron status and reduces the prevalence of anemia in anemic Vietnamese women. Am J Clin Nutrition 2003;78:28490. Yip R. Prevention and control of iron deficiency: policy and strategy issues. J Nutrition 2002;132:802S-805S. Lynch SR. The impact of iron fortification on nutritional anaemia. Best Pract Res Clin Haematol 2005;18:333-46. Rockey DC, Cello JP. Evaluation of the gastrointestinal tract in patients with iron-deiciency anemia. N Engl J Med 1993;329: 1691-5. McIntyre AS, Long RG. Prospective survey of investigations in outpatients referred with iron deficiency anaemia. Gut 1993; 34:1102-7. Bini EJ, Micale PL, Weinshel EH. Evaluation of the gastrointestinal tract in premenopausal women with iron deficiency anemia Am J Med 1998;105: 281-286 Dickey W, Hughes D. Prevalence of celiac disease and its endoscopic markers among patients having routine upper gastrointestinal endoscopy. Am J Gastroenterol 1999;94:2182-6. Choe YH, Kwon YS, Jung MK, et al. Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes. J Pediatr 2001b;139:100-4. Annibale B, Marignani M, Monarca B, et al. Reversal of iron deficiency anemia after Helicobacter pylori eradication in patients with asymptomatic gastritis. Ann Intern Med 1999; 131:668-72. Annibale B, Capurso G, Chistolini A, et al. Gastrointestinal causes of refractory iron deficiency anemia in patients without gastrointestinal symptoms. Am J Med 2001;111:439-45. Dickey W, Kenny BD, McMillan SA, Porter KG, McConnell JB. Gastric as well as duodenal biopsies may be useful in the investigation of iron deficiency anaemia. Scand J Gastroenterol 1997;32: 469-72. Faber K. Achylia gastrica mit Anamie. Medizinishe Klinik 1909;5:1310-25. Wintrobe MM, Beebe RT. Idiopathic hypochromic anemia. Medicine 1933;12:187-243. Hershko C, Hoffbrand AV, Keret D, Souroujon M, Maschler I, Monselise Y, Lahad A. Role of autoimmune gastritis, Helicobacter pylori and celiac disease in refractory or unexplained iron deficiency anemia. Haematologica 2005;90:58595. Cook JD, Brown GM, Valberg LS. The effect of achylia gastrica on iron absorption. J Clin Invest 1964; 43:1185-91. Schade SG, Cohen RJ, Conrad ME. The effect of hydrochloric acid on iron absorption. N Engl J Med 1968;279:621-4. Bezwoda W, Charlton R, Bothwell T, et al. The importance of gastric hydrochloric acid in the absorption of nonheme food iron. J Lab Clin Med 1978;92:108-16. Milman, N, Rosenstock, S, Andersen, L, et al. Serum ferritin, hemoglobin, and Helicobacter pylori infection: a seroepidemiologic survey comprising 2794 Danish adults. Gastroenterology 1998;115:268-74. Suerbaum S, Michetti P. Helicobacter pylori infection. N Engl J Med 2002;347:1175-86. Choe YH, Kim SK, Son BK, et al. Randomized placebo-controlled trial of Helicobacter pylori eradication for iron-deficiency anemia in preadolescent children and adolescents. Helicobacter 1999; 4:135-9. Choe YH, Lee JE, Kim SK. Effect of helicobacter pylori eradication on sideropenic refractory anaemia in adolescent girls with Helicobacter pylori infection. Acta Paediatr 2000;89:1547. Hershko C, Ianculovich M, Souroujon M. A hematologist's view of unexplained iron deficiency anemia in males: Impact Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 7 | 12th Congress of the European Hematology Association 50. 51. 52. 53. 54. 55. 56. of Helicobacter pylori eradication. Blood Cells Mol Dis 2007; 38:45-53. Annibale B, Capurso G, Lahner E, et al. Concomitant alterations in intragastric pH and ascorbic acid concentration in patients with Helicobacter pylori gastritis and associated iron deficiency anaemia. Gut 2003 ; 52: 496-501. Hershko C, Ronson A, Souroujon M, et al. Variable hematologic presentation of autoimmune gastritis: age-related progression from iron deficiency to cobalamin depletion. Blood 2006;107: 1673-79. Stopeck A. Links between Helicobacter pylori infection, cobalamin deficiency, and pernicious anemia. Arch Intern Med 2000;160: 1229-30. Appelmelk BJ, Simoons-Smit I, Negrini R, et al. Potential role of molecular mimicry between Helicobacter pylori lipopolysaccharide and host Lewis blood group antigens in autoimmunity. Infection and Immunity 1996;64:2031-40. Negrini R, Savio A, Appelmelk BJ. Autoantibodies to gastric mucosa in Helicobacter pylori infection. Helicobacter 1997; 1: S13-6. Ma JY, Borch K, Sjostrand SE, et al. Positive correlation between H,K-adenosine triphosphatase autoantibodies and Helicobacter pylori antibodies in patients with pernicious anemia. Scandinavian Journal of Gastroenterology 1994;29:961-5. Claeys D, Faller G, Appelmelk BJ, et al. The gastric H+,K+ATPase is a major autoantigen in chronic Helicobacter pylori gastritis with body mucosa atrophy. Gastroenterology 1998; 115:340-7. 57. Negrini R, Savio A, Poiesi C, et al. Antigenic mimicry between Helicobacter pylori and gastric mucosa in the pathogenesis of body atrophic gastritis. Gastroenterology 1996;111: 655-65. 58. Jassel SV, Ardill JE, Fillmore D, et al. The rise in circulating gastrin with age is due to increases in gastric autoimmunity and Helicobacter pylori infection. Q J Med 1999;92:373-7. 59. Appelmelk BJ, Negrini R, Moran AP, Kuipers EJ. Molecular mimicry between Helicobacter pylori and the host. Trends in Microbiol 1997;5:70-3. 60. Rad R, Schmid RM, Prinz C. Helicobacter pylori, iron deficiency, and gastric autoimmunity. Blood 2006;107:4969-70. 61. Annibale B, Di Giulio E, Caruana P, et al. The long-term effects of cure of Helicobacter pylori infection on patients with atrophic body gastritis. Aliment Pharmacol Ther 2002; 16: 1723-31. 62. Kaptan K, Beyan C, Ural AU, et al. Helicobacter pylori--is it a novel causative agent in Vitamin B12 deficiency? Arch Intern Med 2000;160:1349-53. 63. Haruma K, Mihara M, Okamoto E, et al. Eradication of Helicobacter pylori increases gastric acidity in patients with atrophic gastritis of the corpus-evaluation of 24-h pH monitoring. Alimentary Pharmacology and Therapy 1999;13:155-62. 64. McColl KEL, Murray LS, Gillen D, et al. Randomized trial of endoscopy with testing for Helicobacter pylori compared with non-invasive H pylori testing alone in the management of dyspepsia. Br Med J 2002;324:999-1002. | 8 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Iron Metabolism and Disease Pathophysiology, diagnosis and treatment of the anemia of chronic disease A G. Weiss Department of General Internal Medicine, Clinical Immunology and Infectious Diseases, Medical University of Innsbruck, Austria Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:9-17 B S T R A C T Recently, progress has been made in clarifying the patho-physiological networks underlying ACD. ACD is an immunity driven disease and disturbances of iron homeostasis, an impaired proliferation of erythroid progenitor cells and a blunted response to erythropoietin are major factors in its development. Main regulators of body iron homeostasis, such as hepcidin or hemojuvelin, together with pro- and anti-inflammatory cytokines, cause a diversion of iron traffic which leads to iron retention in macrophages and an iron-restricted erythropoiesis. ACD can be diagnosed by characteristic changes of systemic iron homeostasis such as decreased serum iron concentrations and transferrin saturation while ferritin levels are normal or increased. Nevertheless, the correct evaluation of ACD patients with absolute iron deficiency as a consequence of chronic bleeding episodes is still a clinical challenge since therapeutic measures differ according to iron status. Therapeutic strategies involve treatment of the underlying disease, iron, recombinant human eythropoeitin, or blood transfusions with the appropriate therapy. It is hoped that the advent of new assays will improve diagnosis of functional versus true iron deficiency in ACD, determine predictive parameters for therapy and above all, help choose the best therapeutic regimen in terms of quality of life, good cardiac performance, and a favourable clinical course of the underlying disease. nemia of chronic disease (ACD) is the most frequent anemia in hospitalized patients, and after iron deficient anemia the second most frequent anemia in the world.1 ACD occurs in patients with chronic diseases which are accompanied by acute or chronic immune activation, and is thus also termed anemia of inflammation.2-6 However, data on the exact incidence of ACD are rare. Anemia has been identified in 30-60% of patients with small cell carcinoma,7 and the percentage of anemic cancer patients is further aggravated by therapeutic measures such as radio- and/or chemotherapy.8 An even higher incidence of anemia has been found in association with advanced age and cancer, where 77% of men and 68% of women were anemic, and ACD was the underlying cause of anemia in up to 77% of these patients.9 In addition, features of ACD may also contribute do the development of anemia in the elderly. This depends on many factors and is still not fully understood.9 The incidence of anemia was estimated between 20-60% in patients with autoimmune disorders, such as rheumatoid arthritis or inflammatory bowel disease.7 Anemia is a frequent abnormality in sever- A al infections and in patients with human immunodeficiency virus (HIV) infection with incidence rates between 18% to 95%.10 As with all other causes of ACD, the prevalence and severity of anemia is associated with an advanced stage of disease.11,12 Most interestingly, anemia frequently emerges within a few days in patients with severe acute infections and sepsis. It is still not clear whether the patho-physiology in these conditions is the same as for ACD.13 Anemia with chronic renal failure bears some characteristics of ACD, although the absolute erythropoietin deficiency and the anti-proliferative effects of accumulating urinary excretion products form the pathophysiolgical basis in this setting.14 Furthermore, chronic immune activation in patients with end stage renal disease can arise from contact activation of immune cells by dialysis membranes and/or frequent infection episodes14 which result in pathophysiological changes typical of ACD. Pathophysiology ACD is an immune driven condition in which cytokines and acute phase proteins alter body iron homeostasis, erythroid Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 9 | 12th Congress of the European Hematology Association hepcidin hepcidin liver Fe+2 duodenum Fe+2 + IL-6 LPS monocyte + IL-1 TNF-α Tf/TfR Fe+2 ferritin IL-10 CD3+ macrophage IFN-γ FP-1 + Fe+2 Pathways for iron retention in ACD collaboration between acute phase proteins and cytokines hepcidin progenitor cell proliferation, erythropoietin production and red cell life span. The anemia can be further aggravated by bone marrow infiltration and anti-proliferative effects exerted by tumor cells or microorganisms, accompanying bleeding episodes, deficiencies of vitamin auto-immune hemolysis, concomitant infections such as HP gastritis or chronic renal insufficiency.6,15 Iron retention within cells of the reticuloendothelial system Iron retention within cells of the reticuloendothelial system (RES) is characteristic of the development of ACD leading to subsequent limitation of iron availability for erythroid progenitor cells, and thus to an iron-restricted erythropoiesis. Initial studies demonstrated that injection of mice with interleukin (IL)-1 or tumor necrosis factor (TNF)α resulted in hypoferremia, hyperferritinema and anemia.16 This can on the one hand be related to an increased iron acquisition by cells of the RES, such as macrophages, while on the other hand iron re-distribution from macrophages to the circulation is reduced (Figure 1). Macrophages have multiple pathways to acquire iron which include most importantly erythrophagocytosis,17 uptake of ferrous iron via the transmembrane protein divalent metal transporter-1 (DMT-1),18 of transferrin bound iron via transferrin receptors (TfR) and of hemoglobin/hemopexin-haptoglobin complexes via CD 91 or CD 163.19-21 Pro-and anti-inflammatory cytokines affect these iron uptake pathways differently. TNF-α increases erythrophagocytosis via stimulation of target receptor expression on macrophages and damage of erythrocytes via radical formation thereby reducing erythrocyte half life.22-24 Interferon (IFN)-γ and lipo- Figure 1. Pathophysiological mechanisms underlying ACD. Invasion of micro-organisms or emergence of malignant cells lead to activation of Tcells (CD4+) and monocytes. These cells induce immune effector mechanisms, thereby producing cytokines such as interferon (IFN)-γ (from T-cells) and tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6 or IL-10 (from monocytes/macrophages) which affect hepcidin synthesis in the liver and the iron uptake mechanism in monocytes/macrophages. The latter leads to increased macrophage iron acquisition via induction of erythrophagocytosis, TfR and DMT-1 mediated iron uptake and promotion of iron storage via ferritin. In addition, the expression of the iron exporter ferroportin (FP-1) is downregulated by the concerted action of IFN-γ, lipopolysaccharide (LPS) and hepcidin leading to reduced serum iron levels (Fe+2). For more details please refer to text. polysaccaride (LPS) up-regulate DMT-1 expression with increased iron uptake into activated macrophages25 while IL-4, IL-10 and IL-13 enhance TfR mediated iron uptake into activated macrophages26 and together with TNF-α, IL-1 and IL-6 promote iron storage within macrophages via transcriptional and translational stimulation of ferritin expression27-29 (Figure 1). Importantly, while macrophages have multiple pathways to acquire iron, so far only one route has been identified for iron export from these cells, via the transmembrane protein ferroportin1.30 Ferroportin mRNA expression in human monocytes is down-regulated most prominently by LPS and IFNγ leading to iron retention in these cells.25,31 In addition to cytokines, a liver derived acute phase protein is crucially involved in iron regulation under inflammatory conditions. The expression of hepcidin, a 25 aminoacid cyteine rich peptide, is induced by LPS, IL-6 and TGF-β.32 Over-expression of hepcidin results in hypoferremia33, 34 suggesting that hepcidin may be involved in the diversion of iron traffic occurring in ACD 35 by decreasing duodenal iron absorption and blocking the release of iron from macrophages (Figure 1).36, 37 This was further supported by a study in patients with ACD demonstrating an inverse relationship between monocyte ferroportin expression and circulating pro-hepcidin levels.38 Impairment of erythroid progenitor proliferation and differentiation Impairment of erythroid progenitor proliferation and differentiation is another factor for ACD development. This can be related to pro-apoptotic effects of IFN-γ, IFN-α, TNF-α and IL-1 towards erythroid | 10 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Cytokine effects on erythroid progenitor cell proliferation IL-6 LPS Molecular mechanisms: IL-1 monocyte TNF-α IL-10 CD3+ IFN-αβγ TNF-α inhibitory effect via stroma cells IL-1 acts primarily via IFN-γ induction IFN-α induces apotposis of CFU-e IFN-γ caspase mediated apoptosis involving ceramide IFN-γ induces NO-inhibits heme synthesis Cytokines (IFN-γ) inhibit Epo and SCF formation and functionality Epo Iron restriction due to cytokines/hepdicin kidneys Bone Marrow Fe+2 burst forming units (BFU-e) and colony forming units (CFU-e).5,39 In addition to the limited availability of iron for erythropoiesis, the cytokine mediated downregulation of erythropoietin-receptor expression on progenitor cells, an impaired formation and activity of erythropoietin , a reduced expression of other prohematopoietic factors, such as stem cell factor5,39, 40 as well as direct toxic effects of cytokine inducible radicals such as nitric oxide (NO) or superoxide anion cause this inhibition of erythroid progenitor cell proliferation41 (Figure 2). Acute phase proteins, such as α-1 antitrypsin, effectively bind to TfRs and inhibit TfR mediated iron uptake into erythroid progenitor cells, thus blocking their growth and differentiation.42 Anti-proliferative effects towards erythropoiesis have been described for ferritin43 which can be referred to limitation of iron availability for progenitor cells. Moreover, ACD patients may develop deficiencies of vitamins such as cobalamin or folic acid, conditions which further impair the proliferation of hematopoietic progenitor cells.44 Finally, in ACD in association with cancer radio- and chemotherapeutic interventions can aggravate anemia.45 Reduced formation and biological activity of endogenous erythropoietin Reduced formation and biological activity of endogenous erythropoietin is the third factor in ACD development. Erythropoietin levels in ACD have been found to be inadequate for the degree of anemia in many conditions.46,47 In addition, the biological response of hypoxia in ACD is impaired. This cannot be related to changes in iron homeostasis but rather to negative effects of cytokines on erythropoietin for- Figure 2. Pathways which inhibit the proliferation and differentiation of erythroid progenitors cells by inflammatory cytokines. For more details please refer to the text and to the legend of Figure 1. mation and activity.38 IL-1 and TNF-α induce the formation of toxic radicals thereby damaging erythropoietin producing cells and inhibiting erythropoietin formation.48 This was also observed after the injection of LPS into mice and led to reduced erythropoieitin mRNA expression in the kidneys.48 The responsiveness of erythroid progenitor cells to erythropoietin correlates to the amount of circulating cytokines, since in the presence of high concentrations of IFN-γ or TNF-α, much higher amounts of erythropoietin are needed to restore CFU-e colony formation.49 After binding to its receptor, erythropoietin stimulates members of the signal transducer and activator of transcription (STAT) family and subsequently activates mitogen and tyrosin kinase phosphorylation, processes which are affected and modulated by inflammatory cytokines and the negative feed back regulators they induce48,50 (Figure 3). Diagnosis ACD is mostly a mild to moderate normochromic and normocytic anemia. Diagnosis is based on the characteristic changes of body iron homeostasis to differentiate from iron deficiency anemia (IDA).3-5,23 A definitive diagnosis can be hampered by co-existing chronic bleeding complications, renal insufficiency, the effects of medications, primary disorders of iron homeostasis or of hemoglobin synthesis. The evaluation of ACD includes a determination of body iron status. Ferritin is widely used as a marker of iron storage. While serum ferritin levels are low (<15 µg/L) in patients with IDA, ferritin levels are normal or increased in patients with ACD.51 This is due to two factors. Firstly, the increased ferritin levels reflect iron storage within the RES and secondly, Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 11 | 12th Congress of the European Hematology Association Cytokine effects on Epo production IL-6 Molecular mechanisms IL-1 TNF-α/IL-1induce NF-kB/GATA-2 with suppression of Epo gene promotor LPS monocyte TNF-α IL-10 CD3+ Cytokine mediated radical formation neg. affects Epo producing cells in the kidney IFN-γ Interaction with Epo/EpoR signal transduction (JAK2/STAT5/MAPK/PKC) Reduction of EpoR expression on CFU-e Epo kidneys Bone Marrow Impaired Epo function because of reduced iron available Impaired Epo function due to impaired erythroid progenitor proliferation Fe+2 ferritin expression is also induced by inflammation. Therefore ferritin levels do not relate to the level of iron stores in inflammatory patients as is the case in subjects without inflammation. In addition, serum ferritin levels may also be elevated in conditions such as hyperthyroidism, chronic liver disease, alcohol consumption, and after administration of certain medications.19,52 Thus a cutoff level of 30 µg/L may be more appropriate for detecting patients with true iron deficiency.53 As serum iron concentrations and transferrin saturation (TS), as well as zinc protoporphyrin, are low in both IDA and ACD, these parameters cannot help to differentiate between them. In contrast, the transferrin concentrations move in the opposite direction,38 normal or low in ACD and it is increased in iron-deficiency anemia. The soluble transferrin receptor (sTfR) is a truncated fragment of the membrane receptor, and sTfR levels are increased when the availability of iron for erythropoiesis is low as in iron-deficiency anemia.54 In contrast, sTfR levels in ACD are not significantly different from controls. This is because TfR expression is negatively affected by inflammatory cytokines.55 The determination of sTfR in serum can help a differential diagnosis between patients with ACD and functional iron deficiency or ACD patients with absolute iron deficiency.56 ACD in association with absolute iron deficiency is found in ACD subjects who suffer from blood loss, for example due to gastrointestinal or urogenital tumors, menstruation, inflammatory bowel disease, or intestinal infections. These patients present decreased serum iron levels and TfS, low transferrin and decreased ferritin levels. Calculation of a ratio of sTfR concentration versus Figure 3. Pathways leading to reduced formation and biological activity of erythropoietin. For more details please refer to the text and to the legend of Figure 1. the log of ferritin levels may help to in estimate the demands of iron for erythropoiesis.54 A ratio of sTfR/log ferritin <1 suggests ACD with iron-restricted erythropoiesis, whereas a ratio > 3 is associated with absolute iron deficiency along with ACD. These parameters are also included in a four quarter plot which can be very helpful in the differential diagnosis between ACD and ACD with IDA.57 Determination of the percentage of hypochromic red blood cells or, even more importantly, hypochromic reticulocytes, may be helpful in estimating the iron availability for erythrocyte progenitors. This may also be true for mean cellular hemoglobin and mean cellular volume, which appear to decrease with absolute iron deficiency together with ACD.6,38,58 It will be of interest to see whether the determination of hepcidin or hemojuvelin in serum is helpful in the differential diagnosis between ACD and ACD with IDA. Treatment The persistence of anemia is associated with an impaired cardiac and kidney function, a reduced systemic oxygen delivery, reduced physical activity, fatigue, and reduced in quality of life. In a retrospective review of hemodialysis patients, levels of hemoglobin ″8.0 g/dL were associated with a two-fold increase in the probability of death when compared with hemoglobin ranges of 10.0 to 11.0 g/dL.59 In patients with kidney failure on dialysis, treatment of anemia is associated with improvements in quality of life (QOL) based upon both Karnofsky Score and Sickness Impact Profile.60 In cancer patients undergoing chemotherapy, a significant improvement in QOL with anemia management was observed, with | 12 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 the largest improvement occurring between hemoglobin 11 to 12 g/dL.61 These findings contributed to the development of guidelines for the management of anemia in cancer patients.62 When possible, the therapeutic approach toward ACD is treatment of the underlying disease.4,5,11 When this is not achievable, alternative strategies are necessary. Blood transfusions Blood transfusions are widely used as a rapid and effective therapeutic intervention. They are particularly helpful in the context of severe anemia (Hb < 8 g/dL) or life-threatening anaemia (Hb < 6.5 g/dL) due to ACD or in ACD aggravated by bleeding complications. Blood transfusions have been associated with increased survival in anemic subjects with myocardial infarction.63 Whether blood transfusions induce immuno-modulation with clinically relevant, deleterious effects, remains controversial.64 For example, in patients who underwent surgery for esophageal cancer, the perioperative transfusion of blood was associated with an unfavorable clinical course65 and has been linked to organ dysfunction.66 Blood transfusion may affect the immune status of patients directly64,67 or via the donation of iron to the circulation with the potential consequences described below including an increased risk for infectious complications.68 Some of these studies may be biased by the fact that a more sustained anemia is a reflection of a more advanced disease. Thus, such patients would have a worse prognosis per se, and the transfusion of blood for the correction of anemia may not then account for the negative clinical outcome. Based on these different data it is essential that future studies should address the impact of red blood cell transfusion on the clinical outcome of ACD patients and how leukocyte depletion of transfusions may affect the course of the underlying disease. Iron Iron therapy alone, in the absence of iron-deficiency, is not helpful in patients with ACD. Oral iron is poorly absorbed due to down-regulation of iron absorption in the duodenum.69,70 This has been clearly demonstrated by a clinical study in patients suffering from anemia and active inflammatory bowel disease.71 Moreover, iron therapy for patients with ACD may be potentially damaging, since this it counteracts two potential pathophysiologic mechanisms underlying ACD development. Firstly, iron is an essential nutrient for proliferating organisms. Thus, the withdrawal of iron from microorganisms or tumor cells into the RES is a potentially effective defense strategy to inhibit the growth of pathogens.19,72 Secondly, iron inhibits the activity of IFN-γ,55 a cytokine centrally involved in the co-ordination of cell mediated immune effector mechanisms against invading pathogens. Accordingly, iron loaded macrophages cannot clear infections with various intracellular micro-organisms by IFN-γ mediated pathways.55,72 Moreover, iron therapy in a setting of chronic immune activation promotes the formation of highly toxic hydroxyl-radicals via the catalytic action of the metal by the Haber-Weiss-reaction. This can cause tissue damage, endothelial dysfunction and increase the risk of acute cardiovascular events,73 along with the promotion of carcinogenesis via malignant cell transformation.72 An increased iron availability in serum or tissues has been associated with an increased risk of malignancy,74 and diabetes mellitus.75 Negative effects on immunity with iron therapy can also potentially increase the risk of infectious complications or septicemia in patients with ACD patients.76 Iron therapy in chronic hemodialysis patients has been shown to induce neutrophil dysfunction. Consequently, these patients are unable to phagocytose invading bacteria.77 On the other hand, due to its immune-deactivating potential, iron therapy may have some benefit in ACD in connection with autoimmune disorders. By inhibiting TNF-α formation, iron may reduce disease activity in rheumatoid arthritis or end stage renal disease.78,79 However, as iron is needed for the basic cellular metabolic process, iron must be supplemented to ACD patients with absolute iron deficiency. This can also develop under conditions of intense erythropoiesis80,81 during therapy with erythropoietic agents, as patients exhibit a decrease in TfS and in ferritin to levels 50% to 75% below baseline.80,81 Parenteral (i.v.) iron has been shown to improve response rates to therapy with erythropoietic agents in cancer patients undergoing chemotherapy82 and in patients with chronic kidney disease undergoing dialysis.83 In addition, patients with inflammatory bowel disease and anemia respond well to parenteral iron therapy.84 Patients with ACD and absolute iron deficiency should receive supplemental iron therapy,62,83,85 and i.v. iron supplementation should be considered for patients who are not responsive to therapy with erythropoietic agents and who are suspected to have functional iron deficiency. Iron is more likely to be absorbed and utilized by the erythron rather than by pathogens under these conditions, as demonstrated by an increase in hemoglobin levels without demonstrable infectious complications.82,86 Iron therapy is currently not recommended for ACD patients with high/normal ferritin levels (>100 µg/L) due to the possibility of unfavorable outcomes.55,73-75,77,87 This has been clearly confirmed by a recent prospective study investigating the risk of bacteremia with iron therapy Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 13 | 12th Congress of the European Hematology Association in hemodialysis patients which found that subjects with a TfS > 20% and ferritin levels > 100 µg/L at study entry had a significantly higher risk for bacteremia.86 Importantly, the long term effects of iron therapy, even in iron deficient subjects, on the course of the underlying malignant or chronic infectious disease are almost completely unknown and prospective studies have been unable to define how to treat such patients.4,7,23 Prospective studies must still show whether or not the combination of recombinant human erythropoietin (rhEpo) with iron is an efficient therapeutic approach without the potentially negative side effects described above. Human recombinant erythropoietin rhEpo has been used in ACD patients with autoimmune, infectious (such as HIV) and malignant diseases with varying efficacy,61,62,88 and is currently approved for use in cancer patients undergoing chemotherapy, patients with chronic kidney disease, and in patients with HIV infection undergoing myelosuppressive therapy. It may counter-act the anti-proliferative effects of cytokines by rhEpo23,49 and stimulate iron uptake and heme biosynthesis in erythroid progenitor cells4. Accordingly, a poor response to rhEpo treatment is associated with increased levels of pro-inflammatory cytokines on the one hand and poor iron availability on the other hand.89,90 Currently, several rhEPO are available with different receptor binding affinities and serum half lives.91 The measurement of endogenous erythropoietin levels can be useful for predicting the response to rhEpo treatment in ACD.89 Calculation of a ratio of observed endogenous erythropoietin levels to the predicted ones for the given degree of anemia (O/P ratio) may also be useful.92 ACD patients with high erythropoietin levels (>100 U/L) and increased O/P ratios (>0.9) have a low probability of responding to treatment with rhEPO.89,92 This is also true of patients with high levels of markers of inflammation, and/or high ferritin levels as well as in patients with iron deficiency.6 Although the positive short term effects of rhEpo therapy with the correction of anemia are well documented,61,62,88 hardly any data are available on the effect of rhEpo on the course of underlying disease, particularly since erythropoietin can exert biological effects as well as induce of erythropoiesis. In addition to this, rhEpo also exerts an immunomodulatory effect by interfering with the signal transduction cascade of cytokines.48 In patients with end chronic kidney disease, the long term administration of rhEpo decreased TNF-α levels, and good responders to rhEpo therapy had significantly higher CD28 expression on T cells and reduced IL-10, IL-12, IFN-γ and TNF-α levels compared to poor responders.93 Such anti-inflammatory effects may be of benefit in rheumatoid arthritis, where combined treatment with rhEpo and iron not only increases hemoglobin levels but also reduces of disease activity.78 Furthermore, erythropoietin receptors (EpoR) are found on several malignant cell lines94-96 but substantial concerns were raised concerning the specificity of the antibodies used97 and the biological role of such receptors.98,99 The production of EpoR and erythropoietin by breast cancer cells appears to be regulated by hypoxia, and in clinical specimens of breast carcinoma, the highest levels of EpoR were associated with neo-angiogenesis, tumor hypoxia and infiltrating tumors.96 A recent study investigating the effect of rhEpo therapy on the clinical course of non-anemic patients suffering from metastatic breast carcinoma was discontinued because of a trend towards a higher mortality among patients receiving rhEpo. 100 However, a subsequent follow up study demonstrated that the survival-lines converged at 19 months of follow up and subsequently survival was improved in the rhEPo treated arm.101 This suggests that rhEpo and/or adjunct iron therapy has a short term negative effect in non-anemic cancer patients which requires further investigation.102 This breast cancer trial was based on a study in patients with head and neck tumors which demonstrated that an increase in hemoglobin levels upon rhEpo therapy was associated with a favorable clinical outcome. This was traced back to an improved tumor-oxygenation and an increased susceptibility of the tumor to preoperative chemoradiation therapy.103 In contrast, in a subsequent double-blind prospective study investigating whether target Hb levels (> 13 g/dL for women and > 14 g/dL for men) improved loco-regional control of patients undergoing radiation therapy for squamous cell carcinoma of the head or neck, a slightly poorer prognosis was found in patients treated with rhEpo compared to a placebo.104 A negative effect of anemia normalisation has been observed in patients with chronic kidney disease. Hematocrit levels between 33% and 36% were associated with the best outcomes in mortality and morbidity,105 while both over-correction of anemia to normal hemoglobin levels and insufficient treatment were associated with unfavorable clinical courses.6,56,105,106 Until further data are forthcoming; these observations are also applicable to patients with ACD. Current evidence suggests that rhEpo is safe and effective for the corrective treatment of anemia and to improve the quality of life in ACD patients with malignancy. Importantly, current evidence suggests | 14 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 that Hgb levels should not be normalized, and that target levels for anemia correcting therapy should be no greater than 12 g/dL. The evaluation of EpoR in tumor tissue may help to select which patients should receive rhEpo. This leads to the as yet unsolved questions of the clinical impact of anemia correction on the course of the underlying disease and of defining therapeutic ends point for therapy. We designed, large randomized, double blinded, multi-center placebo controlled studies would help answer these questions in the future. New therapeutic strategies will follow our improved knowledge of the pathophysiology of ACD. These may include the use of iron chelators which can induce the endogenous formation of erythropoietin, new products such as hepcidin or hemojuvelin antagonists which may overcome the retention of iron within the RES, modifiers of erythropoietin and/or EpoR sensitivity, and new hormones and cytokines which can effectively stimulate erythropoiesis under inflammatory conditions. With the availability of new assays, the specificity of the diagnosis of functional versus absolute iron deficiency in ACD, along with predictive parameters for therapy, will produce strategies for the best therapeutic regimen of ACD for each patient. It will be important to define therapeutic end points which are positively associated with quality of life, improved cardiac performance, and a favorable impact on the underlying disease. Acknowledgements Supported by a grant from the Austrian Research Funds, FWF, P-19664 and the European Union project, EUROIRON1. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. References 29. 1. Cross EM. Evaluation and treatment of iron deficiency in adults. Nutr Clin Care 2002;5:220-4. 2. Cartwright GE. The anemia of chronic disorders. Semin Hematol 1966;3:351-75. 3. Matzner Y, Levy S, Grossowicz N, Izak G, Hershko C. Prevalence and causes of anemia in elderly hospitalized patients. Gerontology 1979;25:113-9. 4. Weiss G. Pathogenesis and treatment of anaemia of chronic disease. Blood Rev 2002;16:87-96. 5. Means RT, Jr. Recent developments in the anemia of chronic disease. Curr Hematol Rep 2003;2:116-21. 6. Weiss G, Goodnough LT. Anemia of chronic disease. N Engl J Med 2005;352:1011-23. 7. Goodnough LT, Dubois RW, Nissenson AR. Anemia: not just an innocent bystander? Arch Intern Med 2003;163:1820-2. 8. Harrison L, Shasha D, Shiaova L, White C, Ramdeen B, Portenoy R. Prevalence of anemia in cancer patients undergoing radiation therapy. Semin Oncol 2001;28:54-9. 9. Dunn A, Carter J, Carter H. Anemia at the end of life: prevalence, significance, and causes in patients receiving palliative care. J Pain Symptom Manage 2003;26:1132-9. 10. Sullivan PS, Hanson DL, Chu SY, Jones JL, Ward JW. Epidemiology of anemia in human immunodeficiency virus 30. 31. 32. 33. 34. 35. 36. 37. (HIV)-infected persons: results from the multistate adult and adolescent spectrum of HIV disease surveillance project. Blood 1998;91:301-8. Maury CP, Liljestrom M, Laiho K, Tiitinen S, Kaarela K, Hurme M. Tumor necrosis factor alpha, its soluble receptor I, and -308 gene promoter polymorphism in patients with rheumatoid arthritis with or without amyloidosis: implications for the pathogenesis of nephropathy and anemia of chronic disease in reactive amyloidosis. Arthritis Rheum 2003;48:3068-76. Denz H, Huber P, Landmann R, Orth B, Wachter H, Fuchs D. Association between the activation of macrophages, changes of iron metabolism and the degree of anaemia in patients with malignant disorders. Eur J Haematol 1992;48:244-8. Walsh TS, Saleh EE. Anaemia during critical illness. Br J Anaesth 2006;97:278-91. Eschbach JW. Anemia management in chronic kidney disease: role of factors affecting epoetin responsiveness. J Am Soc Nephrol 2002;13:1412-4. Hershko C, Ronson A, Souroujon M, Maschler Z, Heyd J, Patz J. Variable hematological presentation of autoimmune gastritis:age-related progression from iron deficiency to cobalamin depletion. Blood 2006;107:1673-9. Alvarez-Hernandez X, Liceaga J, McKay IC, Brock JH. Induction of hypoferremia and modulation of macrophage iron metabolism by tumor necrosis factor. Lab Invest 1989;61:319-22. Moura E, Noordermeer MA, Verhoeven N, Verheul AF, Marx JJ. Iron release from human monocytes after erythrophagocytosis in vitro: an investigation in normal subjects and hereditary hemochromatosis patients. Blood 1998;92:2511-9. Andrews NC. The iron transporter DMT1. Int J Biochem Cell Biol 1999;31:991-4. Nairz M, Weiss G. Molecular and clinical aspects of iron homeostasis: From anemia to hemochromatosis. Wien Klin Wochenschr 2006;118:442-62. Hentze MW, Muckenthaler MU, Andrews NC. Balancing acts: molecular control of mammalian iron metabolism. Cell 2004;117:285-97. Moestrup SK, Moller HJ. CD163: a regulated hemoglobin scavenger receptor with a role in the anti-inflammatory response. Ann Med 2004;36:347-54. Moldawer LL, Marano MA, Wei H, et al. Cachectin/tumor necrosis factor-alpha alters red blood cell kinetics and induces anemia in vivo. Faseb J 1989;3:1637-43. Spivak JL. Iron and the anemia of chronic disease. Oncology (Huntingt) 2002;16:25-33. Weiss G. Modification of iron regulation by the inflammatory response. Best Pract Res Clin Haematol 2005;18:183-201. Ludwiczek S, Aigner E, Theurl I, Weiss G. Cytokine-mediated regulation of iron transport in human monocytic cells. Blood 2003;101:4148-54. Weiss G, Bogdan C, Hentze MW. Pathways for the regulation of macrophage iron metabolism by the anti-inflammatory cytokines IL-4 and IL-13. J Immunol 1997;158:420-5. Tilg H, Ulmer H, Kaser A, Weiss G. Role of IL-10 for induction of anemia during inflammation. J Immunol 2002;169:2204-9. Torti FM, Torti SV. Regulation of ferritin genes and protein. Blood 2002;99:3505-16. Theurl I, Ludwiczek S, Eller P, et al. Pathways for the regulation of body iron homeostasis in response to experimental iron overload. J Hepatol 2005;43:711-9. Pietrangelo A. Physiology of iron transport and the hemochromatosis gene. Am J Physiol Gastrointest Liver Physiol 2002;282:G403-14. Yang F, Liu XB, Quinones M, Melby PC, Ghio A, Haile DJ. Regulation of reticuloendothelial iron transporter MTP1 (Slc11a3) by inflammation. J Biol Chem 2002;277:39786-91. Ganz T. Hepcidin-a regulator of intestinal iron absorption and iron recycling by macrophages. Best Pract Res Clin Haematol 2005;18:171-82. Nicolas G, Bennoun M, Porteu A, et al. Severe iron deficiency anemia in transgenic mice expressing liver hepcidin. Proc Natl Acad Sci U S A 2002;99:4596-601. Roy CN, Mak HH, Akpan I, Losyev G, Zurakowski D, Andrews NC. Hepcidin antimicrobial peptide transgenic mice exhibit features of the anemia of inflammation. Blood 2007. Nicolas G, Chauvet C, Viatte L, et al. The gene encoding the iron regulatory peptide hepcidin is regulated by anemia, hypoxia, and inflammation. J Clin Invest 2002;110:1037-44. Laftah AH, Ramesh B, Simpson RJ, et al. Effect of hepcidin on intestinal iron absorption in mice. Blood 2004;103:3940-4. Nemeth E, Tuttle MS, Powelson J, et al. Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 15 | 12th Congress of the European Hematology Association internalization. Science 2004;306:2090-3. 38. Theurl I, Mattle V, Seifert M, Mariani M, Marth C, Weiss G. Dysregulated monocyte iron homeostasis and erythropoietin formation in patients with anemia of chronic disease. Blood 2006;107:4142-8. 39. Wang CQ, Udupa KB, Lipschitz DA. Interferon-gamma exerts its negative regulatory effect primarily on the earliest stages of murine erythroid progenitor cell development. J Cell Physiol 1995;162:134-8. 40. Taniguchi S, Dai CH, Price JO, Krantz SB. Interferon gamma downregulates stem cell factor and erythropoietin receptors but not insulin-like growth factor-I receptors in human erythroid colony-forming cells. Blood 1997;90:2244-52. 41. Maciejewski JP, Selleri C, Sato T, et al. Nitric oxide suppression of human hematopoiesis in vitro. Contribution to inhibitory action of interferon-gamma and tumor necrosis factor-alpha. J Clin Invest 1995;96:1085-92. 42. Graziadei I, Gaggl S, Kaserbacher R, Braunsteiner H, Vogel W. The acute-phase protein alpha 1-antitrypsin inhibits growth and proliferation of human early erythroid progenitor cells (burst-forming units-erythroid) and of human erythroleukemic cells (K562) in vitro by interfering with transferrin iron uptake. Blood 1994;83:260-8. 43. Broxmeyer HE. H-ferritin: a regulatory cytokine that downmodulates cell proliferation. J Lab Clin Med 1992;120:367-70. 44. Rodriguez RM, Corwin HL, Gettinger A, Corwin MJ, Gubler D, Pearl RG. Nutritional deficiencies and blunted erythropoietin response as causes of the anemia of critical illness. J Crit Care 2001;16:36-41. 45. Groopman JE, Itri LM. Chemotherapy-induced anemia in adults: incidence and treatment. J Natl Cancer Inst 1999;91:1616-34. 46. Miller CB, Jones RJ, Piantadosi S, Abeloff MD, Spivak JL. Decreased erythropoietin response in patients with the anemia of cancer. N Engl J Med 1990;322:1689-92. 47. Cazzola M, Ponchio L, de Benedetti F, et al. Defective iron supply for erythropoiesis and adequate endogenous erythropoietin production in the anemia associated with systemiconset juvenile chronic arthritis. Blood 1996;87:4824-30. 48. Jelkmann W. Proinflammatory cytokines lowering erythropoietin production. J Interferon Cytokine Res 1998;18:555-9. 49. Means RT, Jr., Krantz SB. Inhibition of human erythroid colony-forming units by gamma interferon can be corrected by recombinant human erythropoietin. Blood 1991;78:2564-7. 50. Minoo P, Zadeh MM, Rottapel R, Lebrun JJ, Ali S. A novel SHP-1/Grb2-dependent mechanism of negative regulation of cytokine-receptor signaling: contribution of SHP-1 C-terminal tyrosines in cytokine signaling. Blood 2004;103:1398-407. 51. Lipschitz DA, Cook JD, Finch CA. A clinical evaluation of serum ferritin as an index of iron stores. N Engl J Med 1974;290:1213-6. 52. Leggett BA, Brown NN, Bryant SJ, Duplock L, Powell LW, Halliday JW. Factors affecting the concentrations of ferritin in serum in a healthy Australian population. Clin Chem 1990;36:1350-5. 53. Hallberg L. Perspectives on nutritional iron deficiency. Annu Rev Nutr 2001;21:1-21. 54. Punnonen K, Irjala K, Rajamaki A. Serum transferrin receptor and its ratio to serum ferritin in the diagnosis of iron deficiency. Blood 1997;89:1052-7. 55. Weiss G. Iron and immunity: a double-edged sword. Eur J Clin Invest 2002;32 Suppl 1:70-8. 56. Punnonen K, Suominen P, Kuusinen A, Kuiper-Kramer E. Clinical use of soluble transferrin receptor. Clin Chem Lab Med 2000;38:377. 57. Thomas C, Thomas L. Anemia of chronic disease: pathophysiology and laboratory diagnosis. Lab Hematol 2005;11:14-23. 58. Thomas L, Franck S, Messinger M, Linssen J, Thome M, Thomas C. Reticulocyte hemoglobin measurement-comparison of two methods in the diagnosis of iron-restricted erythropoiesis. Clin Chem Lab Med 2005;43:1193-202. 59. Ma JZ, Ebben J, Xia H, Collins AJ. Hematocrit level and associated mortality in hemodialysis patients. J Am Soc Nephrol 1999;10:610-9. 60. Moreno F, Sanz-Guajardo D, Lopez-Gomez JM, Jofre R, Valderrabano F. Increasing the hematocrit has a beneficial effect on quality of life and is safe in selected hemodialysis patients. Spanish Cooperative Renal Patients Quality of Life Study Group of the Spanish Society of Nephrology. J Am Soc Nephrol 2000;11:335-42. 61. Littlewood TJ, Bajetta E, Nortier JW, Vercammen E, Rapoport B. Effects of epoetin alfa on hematologic parameters and quality of life in cancer patients receiving nonplatinum chemother- 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. apy: results of a randomized, double-blind, placebo-controlled trial. J Clin Oncol 2001;19:2865-74. Rizzo JD, Lichtin AE, Woolf SH, et al. Use of epoetin in patients with cancer: evidence-based clinical practice guidelines of the American Society of Clinical Oncology and the American Society of Hematology. J Clin Oncol 2002;20:4083107. Goodnough LT, Bach RG. Anemia, transfusion, and mortality. N Engl J Med 2001;345:1272-4. Vamvakas EC, Blajchman MA. Deleterious clinical effects of transfusion-associated immunomodulation: fact or fiction? Blood 2001;97:1180-95. Langley SM, Alexiou C, Bailey DH, Weeden DF. The influence of perioperative blood transfusion on survival after esophageal resection for carcinoma. Ann Thorac Surg 2002;73:1704-9. Vincent JL, Baron JF, Reinhart K, et al. Anemia and blood transfusion in critically ill patients. Jama 2002;288:1499-507. Cunningham-Rundles S, Giardina PJ, Grady RW, Califano C, McKenzie P, De Sousa M. Effect of transfusional iron overload on immune response. J Infect Dis 2000;182 Suppl 1:S115-21. Taylor RW, Manganaro L, O'Brien J, Trottier SJ, Parkar N, Veremakis C. Impact of allogenic packed red blood cell transfusion on nosocomial infection rates in the critically ill patient. Crit Care Med 2002;30:2249-54. Weinstein DA, Roy CN, Fleming MD, Loda MF, Wolfsdorf JI, Andrews NC. Inappropriate expression of hepcidin is associated with iron refractory anemia: implications for the anemia of chronic disease. Blood 2002;100:3776-81. Laftah AH, Ramesh B, Simpson RJ, et al. Effect of hepcidin on intestinal iron absorption in mice. Blood 2004. Schroder O, Mickisch O, Seidler U, et al. Intravenous iron sucrose versus oral iron supplementation for the treatment of iron deficiency anemia in patients with inflammatory bowel disease-a randomized, controlled, open-label, multicenter study. Am J Gastroenterol 2005;100:2503-9. Kontoghiorghes GJ, Weinberg ED. Iron: mammalian defense systems, mechanisms of disease, and chelation therapy approaches. Blood Rev 1995;9:33-45. Sullivan JL. Iron therapy and cardiovascular disease. Kidney Int Suppl 1999;69:S135-7. Stevens RG, Jones DY, Micozzi MS, Taylor PR. Body iron stores and the risk of cancer. N Engl J Med 1988;319:1047-52. Jiang R, Manson JE, Meigs JB, Ma J, Rifai N, Hu FB. Body iron stores in relation to risk of type 2 diabetes in apparently healthy women. Jama 2004;291:711-7. Bullen J, Griffiths E, Rogers H, Ward G. Sepsis: the critical role of iron. Microbes Infect 2000;2:409-15. Kletzmayr J, Sunder-Plassmann G, Horl WH. High dose intravenous iron: a note of caution. Nephrol Dial Transplant 2002;17:962-5. Kaltwasser JP, Kessler U, Gottschalk R, Stucki G, Moller B. Effect of recombinant human erythropoietin and intravenous iron on anemia and disease activity in rheumatoid arthritis. J Rheumatol 2001;28:2430-6. Weiss G, Meusburger E, Radacher G, Garimorth K, Neyer U, Mayer G. Effect of iron treatment on circulating cytokine levels in ESRD patients receiving recombinant human erythropoietin. Kidney Int 2003;64:572-8. Brugnara C. Iron deficiency and erythropoiesis: new diagnostic approaches. Clin Chem 2003;49:1573-8. Goodnough LT, Skikne B, Brugnara C. Erythropoietin, iron, and erythropoiesis. Blood 2000;96:823-33. Auerbach M, Ballard H, Trout JR, et al. Intravenous iron optimizes the response to recombinant human erythropoietin in cancer patients with chemotherapy-related anemia: a multicenter, open-label, randomized trial. J Clin Oncol 2004;22:1301-7. IV. NKF-K/DOQI Clinical Practice Guidelines for Anemia of Chronic Kidney Disease: update 2000. Am J Kidney Dis 2001;37:S182-238. Gasche C, Waldhoer T, Feichtenschlager T, et al. Prediction of response to iron sucrose in inflammatory bowel disease-associated anemia. Am J Gastroenterol 2001;96:2382-7. Winn RJ. The NCCN guidelines development process and infrastructure. Oncology (Williston Park). 2000;14:26-30. Teehan GS, Bahdouch D, Ruthazer R, Balakrishnan VS, Snydman DR, Jaber BL. Iron storage indices: novel predictors of bacteremia in hemodialysis patients initiating intravenous iron therapy. Clin Infect Dis 2004;38:1090-4. Weinberg ED. Iron loading and disease surveillance. Emerg Infect Dis 1999;5:346-52. Goodnough LT. Red cell growth factors in patients with chronic anemias. Curr Hematol Rep 2002;1:119-23. | 16 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 89. Ludwig H, Fritz E, Leitgeb C, Pecherstorfer M, Samonigg H, Schuster J. Prediction of response to erythropoietin treatment in chronic anemia of cancer. Blood 1994;84:1056-63. 90. Cooper AC, Mikhail A, Lethbridge MW, Kemeny DM, Macdougall IC. Increased expression of erythropoiesis inhibiting cytokines (IFN-gamma, TNF-alpha, IL-10, and IL-13) by T cells in patients exhibiting a poor response to erythropoietin therapy. J Am Soc Nephrol 2003;14:1776-84. 91. Cella D, Dobrez D, Glaspy J. Control of cancer-related anemia with erythropoietic agents: a review of evidence for improved quality of life and clinical outcomes. Ann Oncol 2003;14:5119. 92. Beguin Y, Clemons GK, Pootrakul P, Fillet G. Quantitative assessment of erythropoiesis and functional classification of anemia based on measurements of serum transferrin receptor and erythropoietin. Blood 1993;81:1067-76. 93. Aguilera A, Bajo MA, Diez JJ, et al. Effects of human recombinant erythropoietin on inflammatory status in peritoneal dialysis patients. Adv Perit Dial 2002;18:200-5. 94. Arcasoy MO, Amin K, Karayal AF, et al. Functional significance of erythropoietin receptor expression in breast cancer. Lab Invest 2002;82:911-8. 95. Yasuda Y, Fujita Y, Matsuo T, et al. Erythropoietin regulates tumour growth of human malignancies. Carcinogenesis 2003;24:1021-9. 96. Acs G, Zhang PJ, McGrath CM, et al. Hypoxia-inducible erythropoietin signaling in squamous dysplasia and squamous cell carcinoma of the uterine cervix and its potential role in cervical carcinogenesis and tumor progression. Am J Pathol 2003;162:1789-806. 97. Elliott S, Busse L, Bass MB, et al. Anti-Epo receptor antibodies do not predict Epo receptor expression. Blood 2006;107:1892-5. 98. Brown WM, Maxwell P, Graham AN, et al. Erythropoietin Receptor Expression in Non-Small Cell Lung Carcinoma: A Question of Antibody Specificity. Stem Cells 2007;25:718-22. 99. Henke M, Mattern D, Pepe M, et al. Do erythropoietin receptors on cancer cells explain unexpected clinical findings? J Clin Oncol 2006;24:4708-13. 100. Leyland-Jones B. Breast cancer trial with erythropoietin terminated unexpectedly. Lancet Oncol 2003;4:459-60. 101. Leyland-Jones B, Semiglazov V, Pawlicki M, et al. Maintaining normal hemoglobin levels with epoetin alfa in mainly nonanemic patients with metastatic breast cancer receiving first-line chemotherapy: a survival study. J Clin Oncol 2005;23:5960-72. 102. Heeschen C, Aicher A, Lehmann R, et al. Erythropoietin is a potent physiologic stimulus for endothelial progenitor cell mobilization. Blood 2003;102:1340-6. 103. Glaser CM, Millesi W, Kornek GV, et al. Impact of hemoglobin level and use of recombinant erythropoietin on efficacy of preoperative chemoradiation therapy for squamous cell carcinoma of the oral cavity and oropharynx. Int J Radiat Oncol Biol Phys 2001;50:705-15. 104. Henke M, Laszig R, Rube C, et al. Erythropoietin to treat head and neck cancer patients with anaemia undergoing radiotherapy: randomised, double-blind, placebo-controlled trial. Lancet 2003;362:1255-60. 105. Collins AJ, Ma JZ, Ebben J. Impact of hematocrit on morbidity and mortality. Semin Nephrol 2000;20:345-9. 106. Ross SD, Allen IE, Henry DH, Seaman C, Sercus B, Goodnough LT. Clinical benefits and risks associated with epoetin and darbepoetin in patients with chemotherapyinduced anemia: a systematic review of the literature. Clin Ther 2006;28:801-31. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 17 | Iron Metabolism and Disease Screening hemochromatosis and iron overload C. Camaschella A. Pagani E. Poggiali L. Silvestri Università Vita-Salute and IRCCS San Raffaele, Milan, Italy Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:18-23 A B S T A C T Iron overload may develop in several genetic and acquired conditions, either associated with anemias or with normal hemoglobin levels. At present several approaches are available to early recognize iron overload in otherwise symptomless patients. First level tests are serum iron parameters that allow a distinction between cases with increased transferrin saturation (± serum ferritin) and cases with an isolated increase of serum ferritin. Genetic tests for the most common HFE variants allow the detection of most hemochromatosis patients in the preclinical state so that tissue damage due to iron overload can be prevented by early treatment. New non-invasive techniques to directly determine tissue iron content will become widely available in the future. The ultimate goal of testing for iron overload is to provide treatment by phlebotomy or iron chelation to avoid irreversible iron toxicity. Iron overload The term hemochromatosis was first used in the 19th century to indicate bronze diabetes with cirrhosis. Subsequently the term was used for disease resulting from excessive tissue iron deposition. At present its use is restricted to the genetic disease that leads to iron overload through a deregulation of iron homeostasis. Iron overload is a more general term that refers to conditions of increased total body iron caused by iron supply exceeding iron requirements. Since humans lack a physiological mechanism of iron excretion, increased total body iron may be the result of excessive iron absorption or parenteral iron acquisition. These two modalities usually reflect genetic (primary) and acquired (secondary) disorders, although this distinction is not always clear. Iron stores up to a maximum of 1.0-1.5 g is usual in adult males while iron stores in excess of 5 g can cause significant toxicity. The liver is the major site of iron storage. According to the route of iron entrance (dietary or parenteral) accumulation occurs prevalently in the hepatocytes or in the macrophages. A physiopathological classification of conditions leading to iron overload is shown in Table 1. Primary iron overload refers to inborn errors of iron metabolism, including defects of regulators of iron homeostasis and of iron transporters. The first group of disorders, caused by an inappropriately high duodenal iron absorption and release from macro- | 18 | R phages, are globally called hemochromatosis. Several genetic forms of hemochromatosis have been recognized, most due to defective production of hepcidin, the liver peptide hormone, which is the key regulator of iron homeostasis. The disorders of the second group include hypotransferrinemia and newly described entities, such as DMT1 deficiency and aceruloplasminemia. These are much rarer and associated with anemia. Secondary iron overload occurs in all patients that are treated by multiple blood transfusions, both for congenital and acquired anemias. It is also prevalent in the so called iron loading anemias, which include mainly beta-thalassemia syndromes and congenital dyserythropoietic anemias (CDA), disorders characterized by a high degree of ineffective erythropoiesis. Finally, there are causes of local iron overload such as liver disorders, iron-related brain disorders, or sequestration (hemoglobinuria and pulmonary siderosis). Iron toxicity is similar in primary and secondary iron overload and relates to the well known ability of iron to generate reactive oxygen species (ROS). When transferrin is highly saturated excess iron is present in plasma as NonTransferrin-Bound-Iron (NTBI), which is easily taken up by the liver. NTBI and especially the Labile Plasma Iron fraction, may promote the generation of free hydroxyl radicals, known mediators of tissue damage.1 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Primary iron overload Hereditary Hemochromatosis Hereditary hemochromatosis results from disruption of the molecular mechanisms that regulate iron absorption, leading to a progressive increase of total body iron. Based on the first identified gene this condition is often classified as HFE and non-HFE hemochromatosis. According to our present knowledge of the molecular pathogenesis of the disorder it would be more appropriate to classify these disorders under the more general definition of disorders of the hepcidin pathway.2 The nomenclature of hemochromatosis and the type of inheritance of the different forms are reported in Table 2. Type 1 hemochromatosis is the most common form, due to mutations of the HFE gene. It is the classic adult-onset disease, prevalent in males. From 64 to >90% of these patients have the homozygous C282Y mutation, due to a G->A substitution at nucleotide 845 of the HFE gene. The C282Y mutation is prevalent in Northern Europe and less frequent in Southern Europe, reflecting the ancient origin of the mutation3 and its spread through founder effect and positive selection. A minority of patients are compound heterozygotes for both the C282Y and the H63D mutation due to the C->G transversion at position 187 of the HFE gene or homozygotes for the latter mutation. Compound heterozygous and H63D homozygous patients usually have a mild, non-progressive iron overload. These HFE genotypes are more frequent among patients from Southern Europe where the C282Y mutation is less frequent.4 Type 2 or juvenile hemochromatosis, due to mutations of either hemojuvelin (type 2A) or hepcidin (type 2B) is the most severe form. It affects both sexes and is characterized by early onset of iron overload, hypogonadism and cardiomyopathy. The rare type 3 hemochromatosis, due to mutations of transferrin receptor 2 (TFR2) has a variable phenotype. All these conditions show elevated saturation of transferrin and excessive iron deposition in the hepatocytes. Type 4 hemochromatosis, a dominant disorder due to mutations of the iron exporter ferroportin 1, which behaves as the hepcidin receptor,5 has different genetic, biochemical, histological and clinical features and is considered a disorder distinct from hemochromatosis, often referred to as ferroportin disease (Table 2). However, according to the mutation present, some cases may present features which make it indistinguishable from hemochromatosis. Late presentation of the classic disease includes liver fibrosis and cirrhosis, diabetes, cardiomyopathy, hypogonadism and other endocrinopathies, arthropathy and skin pigmentation. Cirrhotic Table 1. Classification of Iron Overload. Systemic forms Primary Iron overload Normal Hb levels Hemochromatosis (type 1,2,3) Ferroportin disease (type 4) Associated with anemia Atransferrinemia Aceruloplasminemia DMT1 defects Secondary iron overload Normal Hb levels Inappropriate parenteral iron Associated with anemia Chronic blood transfusions Beta-thalassemia syndromes Congenital dyseritropoyetic anemias Sideroblastic anemias Hemolytic anemias Uncertain conditions Neonatal hemochromatosis African (Bantu) iron overload Local forms Liver iron overload Chronic liver diseases Porphyria Cutanea Tarda Dismetabolic syndrome with iron overload Neurologic diseases Neuroferritinopathy Friedreich’s ataxia Pantothenate kinase neurodegeneration Focal sequestration of iron Pulmonary siderosis Renal siderosis Table 2. Genetic types of Hemochromatosis according to Omim (On Line Mendelian Inheritance In Man). Disease Gene Type 1 Hfe Type 2A HJV Type 2B HAMP TFR2 Type 3 *Type 4 SCL40A1 Locus Inheritance Gene Product Phenotype 6p21.3 1q21 19q13.1 7q22 2q32 AR AR AR AR AD Hfe Hemojuvelin Hepcidin Transferrin receptor 2 Ferroportin classic juvenile juvenile classic atypical AR: autosomal recessive, AD: autosomal dominant; *also called ferroportin disease (see text for details). patients have increased susceptibility to hepatocellular carcinoma. The disease should be recognized early (or at least in the precirrhotic phase) and treated by intensive phlebotomy to prevent all the clinical complications. Early presentation of hemochromatosis is often difficult to recognize, because of unspecific symptoms, such as weakness, abdominal pain, weight loss and arthralgia. Some subjects are symp- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 19 | 12th Congress of the European Hematology Association tomless at presentation and have only altered serological iron parameters. Liver function tests may also be normal.6 At present, the possibility of identifying the hemochromatosis genotype makes preclinical diagnosis easier. Other inherited disorders of iron metabolism These disorders are due to genetic defects of proteins involved in iron transport and for this reason are classified as inborn errors of iron metabolism. They cause iron overload associated with anemia and for this reason could be also classified under Iron loading anemias. The prototype disorder of iron transport is genetic hypotransferrinemia, an extremely rare recessive disease, first described in 1961. It is characterized by severe deficiency of transferrin, which appears fully saturated, iron-deficient anemia, high ferritin and liver iron overload. Few patients have been described worldwide and their survival is strictly dependent on transferrin (or plasma) infusions.7 Aceruloplasminemia is a rare recessive disease due to deficiency of ceruloplasmin, a multioxidase protein involved in iron export. Due to defective iron release from stores to transferrin, serum iron and transferrin saturation are low, serum ferritin is high while the liver is iron overloaded.8 The full picture occurs late in life and is dominanted by neurological symptoms, because of iron deposition in the basal ganglia. But atypical iron-deficient anemia predates neurological symptoms.9 Divalent Metal Transporter 1 (DMT1) is a metal transporter expressed at the brush border of the enterocytes and on the endosomal membrane of the erythroblasts where it transports iron to the cytosol. Spontaneous mutations of DMT1 in rodents cause iron-deficiency anemia at birth.10,11 Mutations of DMT1 have been described in young patients with microcytic anemia from birth and iron overload.12-14 Secondary iron overload Iron loading anemias The term iron loading anemias traditionally applies to congenital anemias of variable severity, all characterized by ineffective erythropoiesis, with highly increased intestinal iron absorption and significant iron overload. Thalassemia, especially beta-thalassemia syndromes, is the prototype of these conditions. Iron absorption is mostly increased in untransfused patients with thalassemia intermedia to meet the request of an abnormally expanded erythron, whereas blood transfusions limit erythroid expansion and iron absorption in thalassemia major. Congenital dyserythopoietic anemia (CDA) comprises a group of rare inherited disorders characterized by distinct morphological erythroblast abnormalities and a high degree of ineffective erythropoiesis. Hereditary sideroblastic anemia is an heterogeneous condition whose main feature is defective heme synthesis.15 The most common form results from mutations of aminolevulinic acid (ALA)-synthase 2 and a rarer form, sideroblastic anemia with ataxia, from mutations of ABCB7, which transports iron/sulphur clusters from mitochondria to the cytosol. Due to the interconnection between heme and iron sulfur cluster synthesis it is likely that in the future, inherited sideroblastic anemia will be listed under primary iron overload. The preliminary observation of low levels of hepcidin in iron loading anemias, especially in thalassemia intermedia patients16,17 confirms that deregulation of the same pathway characterizes both primary and secondary iron overload. It also indicates that the erythron has a dominant effect over iron stores in signalling body iron needs and suppressing hepcidin synthesis. The development of iron overload in hemolytic anemias occurs in sporadic cases. Parenteral iron loading Chronic blood transfusions, administered for only reason other than blood loss, result in iron overload. Each unit of transfused red cells provides about 180200 mg iron. This results in a marked increase in total body iron in congenital (or even acquired) anemias where there is a life-long dependence on transfusion. Iron overload in acquired anemia may be relevant in myelodysplastic syndromes with good prognosis. A variable degree of iron overload may be present in patients after therapy for leukemias or lymphoma or in patients recovering after bone marrow transplantation. Excess iron accumulates in macrophages and increased stores are expected to suppress duodenal iron absorption. However, the amount of transfused iron is usually much greater than the small reduction in iron absorption. In addition, in most forms of congenital anemias iron loading occurs both through increased absorption and blood transfusions. Iron overload due to inappropriate parenteral iron therapy is at present an extremely rare occurrence. Inappropriate oral iron treatment, in the absence of a genetic defect that enhances iron absorption, is unable to induce iron overload. Miscellanea Moderate iron loading may occur in chronic liver diseases such as alcoholic cirrhosis, porphyria cutanea tarda (PCT) and liver insufficiency. Underlying mechanisms have not yet been fully explored at the molecular level. Preliminary data in end-stage liver diseases suggest that hepcidin-deficiency plays a role in iron loading and that its produc- | 20 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 tion correlates with hepatic dysfunction.18 Interestingly PCT is associated with HFE mutations, especially C282Y.19 Screening iron overload Serum iron parameters as a screening tool for hemochromatosis Serological iron markers are the most important tool to detect hemochromatosis and are widely available. Transferrin saturation may be calculated directly using serum iron and total iron binding capacity measurements or indirectly when serum iron (µl/L) and transferrin (g/L) are available (transferrin saturation % = serum iron ×100/transferrin×1.42) Elevated transferrin saturation (cut-offs vary from> 45% to > 55%) and serum ferritin above the upper normal limits (200 ng/mL in adult females and 300 ng/mL in adult males) are the thresholds used to screen hemochromatosis type 1, 2 and 3. Detecting type 4 hemochromatosis requires family studies because of the dominant inheritance and high serum ferritin concentration, often with normal transferrin saturation. However, a tendency has been observed towards an increase of transferrin saturation with age.20 Serum iron, transferrin and ferritin should preferably be assessed in fasting conditions. High transferrin saturation reflects increased iron absorption and recycling and high serum ferritin increased liver iron stores. At least two assessments should be made before proposing genetic testing. In the absence of secondary causes of iron overload high iron parameters suggest hemochromatosis. Whereas the clinical penetrance of hemochromatosis is low and variable among different populations, the biochemical expression (increased iron parameters levels) is frequent although age-dependent especially in males (>70%).21,22 Alteration of serum iron parameters allows hemochromatosis patients to be identified in the asymptomatic stage. However, this approach identifies several other conditions that are not associated with hemochromatosis. Clinical information should always be available to correctly interpret iron parameters. Liver and hematological disorders, alcohol intake and the concomitant occurrence of the iron overload-associated metabolic syndrome, should all be considered. Inflammatory indexes (CRP) and serum transaminases should be available for all cases with high serum ferritin to exclude inflammatory conditions and liver necrosis or other alterations. In addition, cancer screening may be indicated in older patients with elevated serum ferritin levels. Hyperferritinemia-cataract syndrome is a rare dominant condition characterized by a constitutive increase in L-ferritin synthesis, because of heterozy- gous mutations of L-ferritin IRE promoter element that hamper repression of L-ferritin translation. The level of serum ferritin is high while transferrin saturation and iron stores are normal. Bilateral cataracts or minimal lens opacities are features of the syndrome.20 Genetic testing for hemochromatosis Genetic testing is widely used to confirm or exclude genetic hemochromatosis. It requires the provision of adequate information about the patient (and the family) and informed consent before testing. Multiple PCR-based strategies have been developed to assess the HFE genotype. Most available tests identify the two most common variants – C282Y and H63D. Commercial tests are available to identify multiple mutations both in HFE and in the other genes. However, it must be remembered that genetic types of hemochromatosis other than HFE are rare. Genetic test results should always take into account the patient clinical data and the biochemical iron parameters. The hemochromatosis genotype only indicates a susceptibility to iron loading and should never be considered outside the context of the iron status. C282Y/C282Y homozygotes are at risk for iron loading. Staging of the disease and evaluation of treatment needs should be made according to ferritin levels. In subjects with normal-borderline levels, monitoring iron parameters yearly is advisable. C282Y/H63D compound heterozygotes and H63D homozygotes are genotypes at low risk of iron overload and monitoring of iron overload can be less stringent. C282Y or H63D heterozygous individuals are not at risk of iron overload unless strong environmental factors coexist. The presence of alcohol intake, PCT or steatohepatitis increase the risk of iron loading (and liver fibrosis) in all genotypes. A search for other mutations in HFE or other genes should be offered to selected cases, especially young subjects and familial cases. These patients should be referred to specialized centers, since second level diagnosis is expensive and time consuming. Rare cases of digenic inheritance with simultaneous (heterozygous) mutations in different genes have been described.23 Molecular tests did not identify genetic haemochromatosis as the cause of an increased transferrin saturation and serum ferritin found in the majority of such cases identified in a large study of a racially diverse population.24 There is therefore no indication for extensive sequencing of multiple genes in most isolated cases since the assays used are expensive and time consuming. General population vs selected cases screening Since information is incomplete as to the natural Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 21 | 12th Congress of the European Hematology Association history of the hemochromatosis, and on the proportion of individuals with the affected genotype that will show progression to clinical disease, genetic screening is not cost effective and is not therefore recommended. Most of the screening strategies are based on transferrin saturation or are two-step, considering genetic evaluation as a second level test to be applied only to positive phenotypes.24,25 On the other hand, evaluating iron parameters in adult males is advisable, preferably starting at the end of the third decade of life. In addition, family testing of affected subjects should be implemented in order to recognize early presenting or symptomless potential patients. All first-degree relatives of a patient should be tested and counselled on the need of disease staging and of phlebotomy treatment. Children should not be tested since the disease is a late-onset. The exception is a high suspicion of juvenile hemochromatosis, a potentially fatal disorder. In this case, children should be referred to specialized centers for diagnosis and treatment. Screening iron loading in secondary forms All chronically transfused patients should undergo periodical assessment of iron status in order to be adequately treated by iron chelation.26 Iron overload may be assessed by iron balance (iron introduced by number of transfusions and iron excreted by chelation treatment), serum ferritin and tissue iron directly evaluated through liver iron concentration by invasive (liver biopsy) and/or non invasive determinations (SQUID or MRI)27,28 and more recently by cardiac iron measurement (when T2* is available).29 In untransfused thalassemia and other iron loading anemias transferrin saturation is usually increased and of limited value. A trend towards increased serum ferritin is considered a reliable index of iron accumulation.30 However, it has been observed that serum ferritin is lower than expected for the liver iron concentration in thalassemia intermedia, probably due to hepcidin suppression and low macrophage iron.31 This would indicate that serum ferritin is not a reliable marker since it may underestimate iron overload and not recognise that these patients should undergo regular evaluation of liver iron concentration. Other serological markers, such as NTBI or LIP have been proposed to assess iron toxicity, but their assay has not yet been standardized and assays are only available in a few research laboratories. Genetic testing for HFE mutations has been applied in secondary iron overload. General experience seems to suggest that severe iron loading occurs independently by HFE mutations although in mild forms and a possible role of the HFE gene cannot be excluded. References 1. Le Lan C, Loreal O, Cohen T, Ropert M, Glickstein H, Laine F, et al. Redox active plasma iron in C282Y/C282Y hemochromatosis. Blood 2005;105:4527-31. 2. Camaschella C. Understanding iron homeostasis through genetic analysis of hemochromatosis and related disorders. Blood 2005;106:3710-7. 3. Distante S, Robson KJ, Graham-Campbell J, Arnaiz-Villena A, Brissot P, Worwood M. The origin and spread of the HFEC282Y haemochromatosis mutation. Hum Genet. 2004;115:269-279 4. Piperno A, Sampietro M, Pietrangelo A, Arosio C, Lupica L, Montosi G, et al. Heterogeneity of hemochromatosis in Italy. Gastroenterology 1998;114:996-1002. 5. Nemeth E, Tuttle MS, Powelson J, Vaughn MB, Donovan A, Ward DM, et al. Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization. Science 2004;306:2090-3. 6. Pietrangelo A. Hereditary hemochromatosis-a new look at an old disease. N Engl J Med 2004;350:2383-97. 7. Beutler E, Gelbart TPL, Trevino R, Fernandez MA, Fairbanks VF. Molecular characterization of a case of atransferrinemia. Blood 2000;96:4071-4. 8. Harris ZL, Takahashi Y, Miyajima H, Serizawa M, MacGillivray RT, Gitlin JD. Aceruloplasminemia: molecular characterization of this disorder of iron metabolism. Proc Natl Acad Sci USA 1995;92:2539-43. 9. Bosio S, De Gobbi M, Roetto A, Zecchina G, Leonardo E, Rizzetto M, et al. Anemia and iron overload due to compound heterozygosity for novel ceruloplasmin mutations. Blood 2002;100:2246-8. 10. Fleming MD, Trenor CC 3rd, Su MA, Foernzler D, Beier DR, Dietrich WF, et al. Microcytic anaemia mice have a mutation in Nramp2, a candidate iron transporter gene. Nat Genet 1997;16:383-6. 11. Fleming MD, Romano MA, Su MA, Garrick LM, Garrick MD, Andrews NC. Nramp2 is mutated in the anemic Belgrade (b) rat: evidence of a role for Nramp2 in endosomal iron transport. Proc Natl Acad Sci USA 1998;95:1148-53. 12. Mims MP, Guan Y, Pospisilova D, Priwitzerova M, Indrak K, Ponka P, et al. Identification of a human mutation of DMT1 in a patient with microcytic anemia and iron overload. Blood 2005;105:1337-42. 13. Iolascon A, d’Apolito M, Servedio V, Cimmino F, Piga A, Camaschella C. Microcytic anemia and hepatic iron overload in a child with compound heterozygous mutations in DMT1 (SCL11A2). Blood 2006;107:349-54. 14. Beaumont C, Delaunay J, Hetet G, Grandchamp B, de Montalembert M, Tchernia G. Two new human DMT1 gene mutations in a patient with microcytic anemia, low ferritinemia, and liver iron overload. Blood 2006;107:4168-70. 15. Bottomley SS. Congenital sideroblastic anemias. Curr Hematol Rep 2006;5:41-9. 16. Papanikolaou G, Tzilianos M, Christakis JI, Bogdanos D, Tsimirika K, MacFarlane J, et al. Hepcidin in iron overload disorders. Blood 2005;105:4103-5. 17. Kearney SL, Nemeth E, Neufeld EJ, Thapa D, Ganz T, Weinstein DA, et al. Urinary hepcidin in congenital chronic anemias. Pediatr Blood Cancer 2007;48:57-63. 18. Detivaud L, Nemeth E, Boudjema K, Turlin B, Troadec MB, Leroyer P et al. Hepcidin levels in humans are correlated with hepatic iron stores, hemoglobin levels, and hepatic function. Blood 2005;106:746-8. 19. Bonkovsky HL, Poh-Fitzpatrick M, Pimstone N, Obando J, Di Bisceglie A, Tattrie C, et al. Porphyria cutanea tarda, hepatitis C, and HFE gene mutations in North America. Hepatology 1998;27:1661-9. 20. Cazzola M. Hereditary hyperferritinaemia/ cataract syndrome. Best Pract Res Clin Haematol 2002;15:385-98. 21. Beutler E, Felitti VJ, Koziol JA, Ho NJ, Gelbart T. Penetrance of 845G→A (C282Y) HFE hereditary haemochromatosis mutation in the USA. Lancet 2002;359:211-8. 22. Olynyk JK, Hagan SE, Cullen DJ, Beilby J, Whittall DE. Evolution of untreated hereditary hemochromatosis in the Busselton population: a 17-year study. Mayo Clin Proc | 22 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 2004;79:309-13. 23. Merryweather-Clarke AT, Cadet E, Bomford A, Capron D, Viprakasit V, Miller A, et al. Digenic inheritance of mutations in HAMP and HFE results in different types of haemochromatosis. Hum Mol Genet 2003;12:2241-7. 24. Adams PC, Reboussin DM, Barton JC, McLaren CE, Eckfeldt JH, McLaren GD, et al. Hemochromatosis and iron-overload screening in a racially diverse population. N Engl J Med 2005;352:1769-78. 25. Gagne G, Reinharz D, Laflamme N, Adams P, Rousseau F. Hereditary hemochromatosis screening: effect of mutation penetrance and prevalence on cost-effectiveness of testing algorithms. Clin Genet 2007;71:46-58. 26. Cohen AR. New advances in iron chelation therapy. Hematology Am Soc Hematol Educ Program 2006:42-7. 27. Brittenham GM, Farrell DE, Harris JW, Feldman ES, Danish EH, Muir WA, et al. Magnetic-susceptibility measurement of human iron stores. N Engl J Med 1982;307:1671-5. 28. St Pierre TG, Clark PR, Chua-anusorn W, Fleming AJ, Jeffrey GP, Olynyk JK, et al. Noninvasive measurement and imaging of liver iron concentrations using proton magnetic resonance. Blood 2005;105:855-61. 29. Pennell DJ. T2* magnetic resonance and myocardial iron in thalassemia. Ann N Y Acad Sci 2005;1054:373-8. 30. Rund D, Rachmilewitz E. Beta-thalassemia. N Engl J Med 2005;353:1135-46. 31. Origa R, Galanello R, Ganz T, Giagu N, Maccioni L, Faa G, et al. Liver iron concentrations and urinary hepcidin in betathalassemia. Haematologica, in press. 2007 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 23 | Hemostasis Epidemiology of coagulation disorders F. Peyvandi M. Spreafico Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milan and Department of Medicine and Medical Specialties, Luigi Villa Foundation, IRCCS Maggiore Hospital, Mangiagalli and Regina Elena Foundation, Milan, Italy Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:24-30 | 24 | he most common congenital deficiency of clotting factors are von Willebrand disease (VWD) and the hemophilias. Bleeding symptoms are also reported for other rarer bleeding disorders, including platelet disorders which will not be discussed in this report. Inherited deficiencies of plasma coagulation factors generally lead to lifelong bleeding disorders. Their severity is inversely proportional to the degree of factor deficiency. T Hemophilia A and B Inherited as X-linked recessive traits, hemophilia A and B are the most common hereditary bleeding disorders caused by a deficiency or dysfunction of blood coagulation factor (F)VIII and FIX. Hemophilias are present worldwide, with a prevalence in the general population of approximately 1:10,000 (hemophilia A) and 1:50,000 (hemophilia B), without ethnic or geographic limitations. They remain still lifethreatening and often disabling conditions despite recent improvements in replacement therapy. Hemophilia A and B have the same clinical presentation, consisting predominantly of acute and chronic hemarthroses, chronic synovitis, restriction of joint movement, and soft tissue hematomas. Bleeding in the central nervous system is uncommon but can occur after relatively light head injury and was formerly the most common cause of death in hemophilia. Gastro-intestinal bleeding, presenting as hematemesis and/or melena, occasionally occurs and its mechanisms should be thoroughly investigated.1 Hemophilia A and B occur in mild, moderate and severe forms, defined by plasma FVIII/FIX levels of 6-30%, 1-5% and less than 1% respectively.2 From 1980 onwards, technological advances in the field of molecular biology have meant the gap in hemophilia treatment and diagnosis has widened significantly between the developed and developing countries. There are 450,000 people with hemophilia A in the world but only 20% of them can expect diagnosis and treatment.3 Data collected by the World Federation of Haemophilia show that, in developing countries, people with hemophilia rarely live beyond childhood. This is because, owing to the limited resources available, hemophilia cannot be given a priority over widespread health problems such as infections and malnutrition.4 Therefore, in those countries where factor concentrates for replacement therapy are scarce, carrier detection and prenatal diagnosis remain the key steps to prevent the birth of hemophiliac children.5 von Willebrand disease Von Willebrand factor is a large multimeric glycoprotein that functions as the carrier protein for FVIII. It is also required for normal platelet adhesion. As such, it functions both in primary (involving platelet adhesion) and secondary (involving FVIII) hemostasis. In primary hemostasis, von Willebrand factor attaches to platelets by its specific receptor glycoprotein Ib on the platelet surface and acts as an adhesive bridge between the platelets and damaged subendothelium at the site of vascular injury. In secondary hemostasis, von Willebrand factor protects FVIII from degradation and delivers it to the site of injury.6,7 von Willebrand disease, due to deficiencies or dysfunction of von Willebrand factor, is the most common hereditary bleeding disorder with, according to epidemiological studies, an estimated prevalence worldwide as high as 1 to 2% in the general population.8-10 In contrast, estimates based on referral for symptoms of bleeding suggest a prevalence of 30 to 100 cases per million, similar to that of hemophilia A.6 Neither ethnic origin nor gender influence the prevalence of von Willebrand disease. Von Willebrand disease is characterized by a lifelong bleeding tendency mainly in mucosal tracts, with easy bruising, frequent epistaxis, and menorrhagia.11 Von Willebrand disease displays both dominant and recessive Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 inheritance. Mutations previously identified in the von Willebrand factor gene are reported on an international database http://www.shef.ac.uk/vwf/.11,12 Von Willebrand disease can be classified into 3 main types. Type 1 (70-80% of cases) is characterized by a partial quantitative decrease of qualitatively normal von Willebrand factor and FVIII. An individual with type 1 von Willebrand disease generally has mild clinical symptoms and the disease is usually inherited as an autosomal dominant trait. However, penetrance may vary remarkably in each family.6,13 In addition, clinical and laboratory findings may vary in the same patient on different occasions. Typically, a proportional reduction in von Willebrand factor activity, von Willebrand factor antigen, and FVIII exists in type 1 disease.6,13 Diagnostic criteria for Type 1 von Willebrand disease were published on behalf of the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee von Willebrand factor subcommittee (ISTH SSC on VWF)14 and recently updated.11 Indeed, diagnosis of type 1 may be difficult, especially in mild cases. This is because patients who, due to von Willebrand gene mutations, present reduced, structurally normal von Willebrand factor cannot be distinguished phenotypically from healthy individuals with von Willebrand factor levels at the lower end of the normal distribution.15 Furthermore, there is no single assay that specifically diagnoses type 1 disease. Mutation analysis could potentially contribute to diagnosis. However, until recently, a complete gene analysis has only been conducted in a limited number of patients.16 Fifteen to twenty percent of patients with von Willebrand disease have type 2 defect, a variant with primarily qualitative defects of von Willebrand factor. Type 2 can be either autosomal dominant or recessive. Of the 4 known type 2 subtypes (ie, 2A, 2B, 2M and 2N), type 2A is the most common.14 Type 3 is the most severe form of von Willebrand disease. In the homozygous patient, type 3 is characterized by marked deficiencies of both von Willebrand factor and FVIII, by the absence of von Willebrand factor in platelets and endothelial cells, and a lack of response to desmopressin acetate (DDAVP). Type 3 von Willebrand disease is characterized by severe clinical bleeding and is inherited as an autosomal recessive trait. Consanguinity is a common cause of this type in some populations.17 Less severe clinical and laboratory abnormalities may occasionally be present in heterozygotes. Together with von Willebrand disease, hemophilia A and B include 95% to 97% of all the inherited deficiencies of coagulation factors.18 The remaining defects (fibrinogen, prothrombin (FII), FV, combined FV+FVIII, FVII, FX, FXI and FXIII deficiencies), are generally transmitted as autosomal recessive traits. These deficiencies are quite rare in most populations, with prevalence of clinically relevant forms ranging from 1:500,000 for FVII deficiency to 1 in 2 million for prothrombin (FII) and FXIII deficiency.19 In areas where consanguineous marriages are frequent, such as Middle-Eastern countries and Southern India, these coagulation disorders are more frequent and are together more prevalent than haemophilia B, representing a significant clinical problem.20 Rare coagulation disorders are generally less severe than hemophilias, with clinical manifestations ranging from mild to severe.2,19 Exceptions are FX and FXIII, that are at least as severe as hemophilia A and B. They also affect women and are associated with serious obstetric and gynecological problems.2,20 These deficiencies are characterized by the early onset of life-threatening symptoms such as umbilical cord and central nervous system bleeding. Central nervous system bleeding is also a common symptom in severe FVII deficiency. Here it is reported in 15-60% of cases.21,22 It presents shortly after birth and is associated with high morbidity and mortality.23 Other severe symptoms such as recurrent hemoperitoneum during ovulation, as well as limbendangering hemarthroses and soft tissue hematomas, are more frequent in patients with FII, FX, and FXIII deficiency than in other rare coagulation disorders. Common to all rare coagulation disorders is the occurrence of excessive bleeding at the time of invasive procedures such as circumcision and dental extraction. Bleeding in mucosal tracts (particularly epistaxis and menorrhagia) is also a relatively frequent feature.20,23,24 The majority of rare coagulation disorders are expressed phenotypically by a parallel reduction of plasma factors as measured by functional assays and immunoassays (so-called type I deficiencies). Qualitative defects, characterized by normal, slightly reduced or increased levels of factor antigen contrasting with much lower or undetectable functional activity (so-called type II deficiencies), are less frequent.18 Inherited as recessive traits, rare coagulation disorders are due in most cases to mutations in the genes that encode the corresponding coagulation factors. Exceptions are the combined deficiencies of FV+FVIII,20 and of vitaminK-dependent proteins (FII, FVII, FIX, and FX).25 There are caused respectively by mutations in genes encoding proteins involved in the FV and FVIII intracellular transport,26,27 and in genes encoding enzymes involved in post-translational modifications and in vitamin K metabolism.28,29 Whereas hemophilia A is due to an inversion mutation involving introns 22 or 1 of the FVIII gene in approximately half of the patients, rare coagulation disorders are often due to mutations which are unique to each kindred scat- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 25 | 12th Congress of the European Hematology Association RBDs Hemophilia A+B von Willebrand disease Hemophilia type unknown Platelet disorders Other hereditary bleeding disorders: type unknown tered throughout the genes.18 Current treatment of rare coagulation disorders is based on the replacement of the deficient coagulation factor by plasmaderived products. In European countries, a good quality of life is assured to patients with rare coagulation disorders, both in terms of availability and safety of coagulation factors. By contrast, in developing countries, economic constraints, limitated laboratory resources and the scarce availability of therapeutic products make the provision of an acceptable level of care and quality of life impossible. Thus, molecular characterization and prenatal diagnosis remain the key steps for the prevention of the birth of children affected by rare coagulation disorders in developing countries. Indeed, patients with these deficiencies rarely live beyond childhood because management is still largely inadequate.5 Epidemiology can be defined as the study of the frequency and distribution of diseases in specific populations. The distribution of coagulation disorders in different part of the world is often unknown. It is essential, therefore, to increase the knowledge of the clinical and therapeutic aspects of each disorder and to establish in which region and population intervention is needed. Such intervention could include genetic prevention as well as the development of drugs, particularly for those deficiencies with no available therapeutic concentrate. Data on the distribution of hemophilia A and B are quite well established and described in literature. This is mainly due to the higher prevalence and the severity of symptoms. Instead, data on epidemiology of the Figure 1. Distribution of bleeding disorders from World Federation of Haemophilia global survey. other coagulation disorders, are limited, particularly in developing countries. This is also because the biologic heterogeneity and variable presentation of these diseases make an accurate diagnosis difficult. Low incidence means few centres have the possibility to follow and manage a consistent number of patients and scientific reports in literature are usually limited to small groups of affected patients. In recent years, however, there has been an attempt to collect more information with the creation of national registries [France, www.francecoag.org; Switzerland, www.aekreg.ch; North-America;24 England, UKHCDO; www.ukhcdo.org, ] and international registries [www.rbdd.org]. In 2002 to improve understanding of the distribution of coagulation deficiencies, a report compared the number of patients affected by coagulation disorders in the Islamic Republic of Iran with those registered in the UK by the Hemophilia Centre Directors Organization (UKHCDO), and in Italy by the Istituto Superiore di Sanità and the Associazione Italiana Centri Emofilia (AICE).19 This comparison was possible due to their similar general populations (approximately 60 million) and the availability of National Registries of inherited bleeding disorders. In Iran, rare coagulation disorders were clearly more prevalent than in Italy and the UK (15% vs 7% UK and 5% Italy), whereas in all the three countries hemophilia A (Iran: 65%; UK: 77%; Italy: 80%) was the most frequent bleeding disorder, followed by hemophilia B (Iran: 20%; UK: 16%; Italy: 15%).19 This survery confirmed that in populations where the practice of con- | 26 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 A World Federation of Hemophilia survey 40 35 % of affected patients 35 30 24 25 20 15 10 11 9 5 9 6 3 7 0 FIBRINOGEN FII FV FV-FVIII FVII FX FXI FXI deficiency Rare Bleeding Disorder Database survey B 30 % of affected patients 25 24 25 20 16 15 11 10 8 5 7 6 2 0 FIBRINOGEN FII FV FV-FVIII FVII FX FXI FXI deficiency Figure 2. Prevalence of each RBD in the WFH global survey [23] (A) and in the RBDD survey [www.rbdd.org] (B) sanguineous marriage is widespread the frequency of rare congenital coagulation disorders is higher. However, these data only related to three countries. More detailed information and comparable data can only be obtained from a global survey. The World Federation of Haemophilia represents the most important organization. That, since 1998, annually performs a worldwide survey on people with hemophilia, von Willebrand disease and rare coagulation disorders. The last global survey of the World Federation of Haemophilia, which collected data for the years 2004 and 2005, was published in 2006 [ref. #30, http://www.wfh.org/2/7/7_0_Link7_ GlobalSurvey2005.htm]. The survey includes information from 98 participating countries, covering 88% of the world population. Of these countries, 49 used national registries to report information about 186,089 patients with hemophilia, von Willebrand disease and other bleeding disorders throughout the world. Of these, 123,942 were affected by hemophilia A and B (66,7%), 44,471 by von Willebrand disease (23,9%), 6,934 (3,7%) by rare bleeding disorders, 2,648 (1,4%) by platelet disorders and 8,094 (4,3%) by unknown type of hemophilia or rare disorders. Figure 1 shows the prevalence of hemophilia, von Willebrand disease, rare coagulation disorders and platelet disorders, calculated on the total number of affected patients reported by countries responding to the World Federation of Haemophilia global survey. As expected, hemophilia A and B, followed by von Willebrand disease, are the most frequent bleeding disorders. Frequencies differ around the world. The reported prevalence of hemophilia A and B seems to be higher in South America, Africa, the Middle East and Asia (approximately 80%) than in North America, Europe and Oceania (approximately 55%). von Willebrand disease was reported to be more frequent in North America, Europe and Oceania (32 to 39%) than in South America, Africa, the Middle East and Asia (6 to 10%). This is probably due to underdiagnosis of von Willebrand disease in countries with low economic resources. However, a previous survey31 reported that this is not always the case in the developing world. Infact, there is significant support from the government for the management of these patients in southeast Asia, South America and Africa. Rare coagulation disorders seem to have the same prevalence in North America, Europe, the Middle East and Africa. These data contrast with previous reports of a higher frequency of the recessive rare coagulation disorders in countries where the practice of consanguineous marriage is widespread, particularly in Middle Eastern countries.32,33 As far as the hemophilias are concerned, 93 of the 96 responding countries (97%) were able to provide data on the number of affected patients. In contrast, only 36 of the 96 responding countries (37%) provided specific information on the number of patients affected by rare coagulation disorders, and 41 countries gave statistics referring to patients affected by other hereditary bleeding disorders: type unknown, which could include both rare coagulation disorders, von Willebrand disease and platelet disorders without being able to distinguish them. Furthermore, only 10 of the 96 responding countries were from Africa and only 3 of them gave information on the number of patients affected by rare coagulation disorders. No detailed information came from the Middle East, as only 3 of the 11 responding countries supplied the number of patients affected by rare coagulation disorders. To sum up, the World Federation of Haemophilia global survey gives an indication of the variety but not the real world distribution of bleeding disorders, in particular von Willebrand disease and rare coagulation disorders. Perhaps, the lack of comprehensive information and detailed responses might be due to the limited number of reliable national registries for these disorders, particularly in developing countries where political, social and economic situations often mean affected patients are not properly diagnosed and managed. Indeed, without participation and funding from governments and insurance agencies, it is impossible to contemplate a basic level of care for all affected people with hereditary bleeding disorders. However, the World Federation of Haemophilia is making many effort to improve the global survey and it is hoped that more comprehensive data will be Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 27 | 12th Congress of the European Hematology Association Rare coagulation distribution according to the World Federation of Hemophilia global survey Fibrinogen FII FV FV+FVIII FVII FX FXI FXIII Rare coagulation disorders distribution according to the RBDD suvey Fibrinogen FII FV FV+FVIII obtained in the future. A further indication of the world-wide prevalence of rare coagulation disorders can also be obtained by comparing the frequency of rare coagulation disorders collected by the World Federation of Haemophilia global survey with that of the International Rare Bleeding Disorders Database (RBDD, www. rbdd.org) survey.34 The Rare Bleeding Disorders Database collected data from 61 responding treatment centres all over the world, for a total of 2,916 patients affected by rare coagulation disorders, FVII FX FXI FXIII Figure 3. Prevalence of each RBD in different world regions according to the WFH global survey [23] (A) and the RBDD survey [www.rbdd.org] (B). including severe, moderate or mild deficiencies. As shown in Figures 2 and 3, the prevalence of each rare coagulation disorder is similar in the two surveys, with two major exceptions: combined FV+FVIII deficiency and FXI deficiency. The high frequency of FV+FVIII deficiency reported in the Rare Bleeding Disorders Database survey probably indicates the need for a more detailed revision of patient diagnosis to exclude misdiagnosis of FV deficiency associated with mild hemophilia. The majority of cases of FXI deficiency, reported in | 28 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 literature are of Ashkenazi Jewish origin, the frequency of heterozygosity for FXI deficiency being as high as 8%.19 Many Ashkenazi Jews reside in Israel, but large populations live in Western Europe and the United States. The higher frequency of FXI deficiency observed in the World Federation of Haemophilia survey might be derived from data provided from countries not included in the Rare Bleeding Disorders Database with large Jewish populations. In conclusion, recents years have seen efforts to increase our knowledge of the epidemiology of coagulation disorders, particularly of those which, due to their frequency, are considered orphan diseases. However, obtaining specific and global information is still problematic, principally because carrying out comprehensive studies in all countries is difficult. This is particularly true in developing countries that are often those with higher incidence rates. Furthermore, in these countries, the priority is not given to these life-threatening and often disabling condition due to of limited resources. Affected individuals therefore, often do not survive childhood, or are not diagnosed and treated at all. So national registries must be improved and integrated into a single international registry. This instrument is an essential tool to improve knowledge on the prevalence of patients affected by each coagulation disorder in different regions of the world. A comprehensive analysis of patient distribution will help to identify and define intervention at both national and international levels to improve the access to care for all affected patients, optimizing diagnosis, treatment and management. Greater knowledge of the worldwide prevalence and distribution of coagulation disorders could increase pharmaceutical interest in the development and distribution of replacement products (e.g. FV, FX) which are currently unavailable. However, product safety and cost must always be strictly controlled, particularly in countries with limited resources. Acknowledgments We are grateful to the World Federation of Haemophilia (WFH) for its continuous effort in the annual global survey data collection, to all those Centres that contribute to the Rare Bleeding Disorders Database (RBDD: http://www.rbdd.org/ alreadyjoined.htm) data collection, and to Prof. Pier Mannuccio Mannucci who critically reviewed this manuscript with useful criticism. References 1. Laffan MA, Lee C. Inherited bleeding disorders. In: Tuddenham EGD, Hoffbrand AV, Catovsky D, eds Postgraduate haematology. Oxford, United Kingdom: Blackwell Publishing Ltd 2005:825-41 2. Peyvandi F, Mannucci PM. Rare coagulation disorders. Thromb Haemost 1999;82:1207-14 3. Srivastava A. Delivery of haemophilia care in the developing world. Haemophilia 1998;4:33–40 4. Lee CA. World Federation of Haemophilia developing world programmes. Haemophilia 1998;4(suppl2):59–63 5. Peyvandi F. Carrier detection and prenatal diagnosis of hemophilia in developing countries. Semin Thromb Hemost. 2005;31:544-54. 6. Mannucci PM. Treatment of von Willebrand’s Disease. NEJM 2004;351:683-94. 7. Federici AB. Diagnosis of inherited von Willebrand disease: a clinical perspective. Semin Thromb Hemost 2006;32:555-65. 8. Rodeghiero F, Castaman G, Dini E. Epidemiological investigation of the prevalence of von Willebrand’s disease. Blood 1987;69:454-9. 9. Werner EJ, Broxson EH, Tucker EL, Giroux DS, Shults J, Abshire TC. Prevalence of von Willebrand disease in children: a multiethnic study. J Pediatr 1993;123:893-8. 10. Bowman M, James P, Godwin M, Rapson D, Lillicrap D.The Prevalence of von Willebrand Disease in the Primary Care Setting. Blood (ASH Annual Meeting Abstracts) 2005;106:1780 (poster session). 11. Sadler JE, Budde U, Eikenboom JC, Favaloro EJ, Hill FG, Holmberg L, Ingerslev J, et al. Update on the pathophysiology and classification of von Willebrand disease. A report of the Subcommittee on von Willebrand Factor. J Thromb Haemost 2006;4:2103-14. 12. Peyvandi F, Jayandharan G, Chandy M, Srivastava A, Nakaya SM, Johnson MJ, Thompson AR, et al. Genetic diagnosis of haemophilia and other inherited bleeding disorders. Haemophilia 2006;12 (Suppl. 3):82–9. 13. Riddel JP Jr, Aouizerat BE. Genetics of von Willebrand disease type 1. Biol Res Nurs. 2006;8:147-56 . 14. Sadler JE, Rodeghiero F; ISTH SSC Subcommittee on von Willebrand Factor. Provisional criteria for the diagnosis of VWD type 1. J Thromb Haemost 2005;3:775-7 . 15. Goodeve A, Eikenboom J, Castaman G, Rodeghiero F, Federici AB, Batlle J, et al. Phenotype and genotype of a cohort of families historically diagnosed with type 1 von Willebrand disease in the European study, Molecular and Clinical Markers for the Diagnosis and Management of Type 1 von Willebrand Disease (MCMDM-1VWD). Blood 2007;109:112-21. 16. International Society on Thrombosis and Haemostasis Scientific and Standardization Committee VWF Information Homepage. Available at: http://www.vwf.group.shef.ac.uk. Accessed July 16, 2006. 17. Lak M, Peyvandi F, Mannucci PM. Clinical manifestations and complications of childbirth and replacement therapy in 385 Iranian patients with type 3 von Willebrand disease. Br J Haematol 2000;111:1236-9. 18. Tuddenham EGD, Cooper DN. The Molecular Genetics of Haemostasis and Its Inherited Disorders. Oxford, United Kingdom: Oxford Medical Publications; 1994. Oxford Monography on Medical Genetics No. 25 19. Peyvandi F, Duga S, Akhavan S, Mannucci PM. Rare coagulation deficiencies. Haemophilia 2002;8:308-21. 20. Mannucci PM, Duga S, Peyvandi F. Recessively inherited coagulation disorders. Blood 2004;104:1243-52. 21. Peyvandi F, Mannucci PM, Asti D, Abdoullahi M, Di Rocco N, Sharifian R. Clinical manifestations in 28 Italian and Iranian patients with severe factor VII deficiency. Haemophilia 1997;3:242-6. 22. Mariani G, Herrmann FH, Dolce A, Batorova A, Etro D, Peyvandi F, et al. Clinical phenotypes and factor VII genotype in congenital factor VII deficiency. Thromb Haemost 2005;93:481-7. 23. Bolton-Maggs PH, Perry DJ, Chalmers EA, Parapia LA, Wilde JT, Williams MD, et al. The rare coagulation disorders review with guidelines for management from the United Kingdom Haemophilia Centre Doctors’ Organisation. Haemophilia 2004;10:593-628. 24. Acharya SS, Coughlin A, Dimichele DM. North American Rare Bleeding Disorder Study Group. Rare Bleeding Disorder Registry: deficiencies of factors II, V, VII, X, XIII, fibrinogen and dysfibrinogenemias. J Thromb Haemost 2004;2:248-56. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 29 | 12th Congress of the European Hematology Association 25. Zhang B, Kaufman RJ, Ginsburg D. LMAN1 and MCFD2 form a cargo receptor complex and interact with coagulation factor VIII in the early secretory pathway. J Biol Chem. 2005;280:25881-6. 26. Nichols WC, Seligsohn U, Zivelin A, Terry VH, Hertel CE, Wheatley MA, Moussalli MJ, et al. Mutations in the ER-Golgi intermediate compartment protein ERGIC-53 cause combined deficiency of coagulation factors V and VIII. Cell 1998;93:6170. 27. Zhang B, Cunningham MA, Nichols WC, Bernat JA, Seligsohn U, Pipe SW et al. Bleeding due to disruption of a cargo-specific ER-to-Golgi transport complex. Nat Genet 2003;34:220-5. 28. Brenner B. Hereditary deficiency of all vitamin K-dependent coagulation factors. Thromb Haemost 2000;84:935-6. 29. Rost S, Fregin A, Ivaskevicius V, Conzelmann E, Hortnagel K, Pelz HJ, Lappegard K, et al. Mutations in VKORC1 cause war- 30. 31. 32. 33. 34. farin resistance and multiple coagulation factor deficiency type 2. Nature 2004;427:537-41. World Federation of Hemophilia Report on the annual Global survey 2005. Srivastava A, Rodeghiero F. Epidemiology of von Willebrand disease in developing countries. Semin Thromb Hemost 2005;31:569-76. Peyvandi F, Asselta R, Mannucci PM. Autosomal recessive deficiencies of coagulation factors. Rev Clin Exp Hematol. 2001;5:369-88. Bauduer F, Ducout L, Dutour O, Degioanni A. Is there a ‘Basque’ profile regarding autosomal recessive deficiencies of coagulation factors? Haemophilia 2004;10:276-9. Peyvandi F, Kaufman RJ, Seligsohn U, Salomon O, BoltonMaggs PH, Spreafico M, et al. Rare bleeding disorders. Haemophilia 2006;12 Suppl 3:137-42. | 30 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Hemostasis Recent advances in hemophilia management C. Négrier1-2 Y. Dargaud1-2 J-L Plantier1 1 EA3735, IFR62, Université Lyon 1, Faculté de Médecine R. Laennec, Lyon; 2 Hospices Civils de Lyon, Service d’Hématologie Biologique, Centre de traitement de l’hémophilie, Hôpital Edouard Herriot, Lyon, France Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:31-38 A B S T R A C T In the last few decades, there have been dramatic improvements in the management of hemophilia. Hemophilia has moved from a fatal or disabling disease to a hereditary disorder and treatments that can improve clinical outcome have become available. The safety of anti-hemophilic clotting factor concentrates has been dramatically improved and no major infection transmitted by plasma-derived or recombinant products has been recorded since the late ’80s. The development of virally safe factor concentrates through a combination of improved donor selection and screening, effective virucidal technologies, and the exploitation of biotechnology-engineered recombinant proteins have provided an impressive safety record with regard to pathogen transmission. Despite concerns about the potential risk of prion transmission, the major complication of treatment is currently represented by the development of inhibitory antibodies following clotting factor administration, mainly during childhood. The progressive development of long-term prophylaxis in developed countries, and surgical correction of disabilities, have markedly improved the quality of life of hemophiliacs. Current efforts are mainly focused on improving the safety of plasma-derived products and bioengineering recombinant proteins that have been modified to enhance pharmacokinetic properties and/or reduce immunogenicity. In addition, several preclinical and clinical studies are currently being carried out for optimizing and individually designing therapeutic regimens using recently developed or revisited coagulation assays. Some attempts to cure hemophilia through gene therapy have been made without significant clinical efficacy in humans, but, from a clinical perspective, this represents the ultimate goal. emophilia is a sex-linked genetic disorder resulting from a deficiency in factor VIII (hemophilia A) or factor IX (hemophilia B) coagulant activity. In most patients, the plasma level of factor VIII (FVIII)/factor IX (FIX) predicts the clinical severity of the disease. Severe hemophilia patients are subject to frequent joint and intramuscular bleeds, and those who are not on prophylaxis have an average of 20 to 30 episodes of spontaneous or trauma-related bleeds per year.1 Treatment usually consists of replacing the missing coagulation factor from exogenous sources. Modern and effective management of hemophilia only became possible with the development of concentrated forms of plasma-derived coagulation factors in the late 1960s. Plasma from multiple donors was pooled, but this practice was a major contributor to the transmission of blood-borne infectious agents such hepatitis B, hepatitis C and HIV.2-4 The subsequent evolution of coagulation factor replacement therapy focused on maximizing viral safety through the H expansion of donor selection and screening tests, and the implementation of chromatographic purification and viral inactivation steps (Figure 1). However, there is still the risk of parvovirus, hepatitis A (HAV) and emerging pathogens such as prions.5 Recombinant FVIII (rFVIII)/FIX concentrates, with very remote risk of infection, were developed in the late 1980s following the cloning and sequencing of FVIII and FIX.6-8 Human rFVIII can only be produced using mammalian cellculture systems due to the complex glycosylation and other post-translational modifications required for its full co-factor activity. While culture media formerly contained human or animal-derived proteins, more recent media utilize chemically synthesized or genetically engineered molecules. Impurities derived from the medium and cultured cells are removed through various chromatographic steps. All currently available rFVIII products are purified using immunoaffinity chromatography employing a murine monoclonal antibody directed against human FVIII. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 31 | 12th Congress of the European Hematology Association Subfractional-O Low purity pdFVIII Intermediate-purity concentrates rFIX High-purity concentrates Cryo-precipitate Late Mid Early Late Early 1950s 1960s 1970s 1970s 1980s Donor/plasma screening for HBV Plasma fractionation rFVIII Mid 1980s Late 1980s Heat-treated concentrates widely Heat treatment of pdFVIII Early 1990s Late 1990s Early 2000s HIV/HCV screening Immunoaffinity, S/D, iron exchange Qualification of donors inventory hold, NAT; nanofiltration rFVIII, recombinant FVIII; rFIX, recombinant FIX; pdFVIII, plasma derived FVIII; HBV, hepatitis B; HCV, hepatitis C; S/D, solvent detergent; NAT, nucleid acid testing Figure 1. Evolution of FVIII/FIX concentrates in the last 50 years. Although no evidence of viral transmission has been recorded with any rFVIII product, a remote theoretical risk of transmitting a human-derived infectious agent still remains in the first generation products, since human and animal proteins were not completely eliminated from the production process. Later generations of recombinant clotting factors have therefore been developed with a progressive elimination of animal or human-derived raw materials. Therapeutic usage of clotting factor concentrates Propylaxis or “on demand” therapy? Severe hemophilia patients (FVIII/FIX<1 IU/dL) suffer from repeated bleeding episodes which result in chronic painful joint disease and deformity known as haemophilic arthropathy.9 The conventional treatment approach is episodic on demand therapy, where the missing factor concentrate is administered as soon as possible after the onset of a bleeding event. Alternatively, the missing factor may be administered at regular intervals to prevent bleeding, in the so-called prophylactic therapy regime to prevent lifethreatening hemorrhages and musculo-articular bleedings.10 The rationale for prophylactic treatment is to maintain clotting factor activity levels above 1% and therefore to convert the bleeding phenotype of patients with severe hemophilia to a milder bleeding pattern similar to that of patients with moderate hemophilia.11,12 Several studies have demonstrated that primary prophylactic therapy improves outcome13 in comparison with on demand treatment strategies. Primary prophylaxis in hemophilia has recently been evaluated in a prospective randomized controlled trial conducted in the United States.14 Prophylaxis should be started at an early age (usually before the age of 2) either before or after the first joint bleed. The 25-year Malmö experience indicates that treatment is most effective when administered in relatively large doses (25-40 IU/kg) at least 3 times per week,15 although less demanding treatment modalities have also been described. One of the advantages of these dose-escalating regimes is to avoid the insertion of a central venous access device which is associated with a significant risk of infectious or/and thrombotic complications.16,17 These regimens begin with a weekly injection via peripheral veins. Infusion therapy is increased in either frequency or quantity of factor unit per kg if breakthrough bleedings occur. The total annual consumption of factor on prophylaxis regimens varies considerably, and there is evidence that the lower doses used in the Netherlands have been as effective in protecting the joints as the higher doses used in Sweden.18 A wider application of prophylaxis therapy is also limited by its high cost. It is, however, generally agreed that prophylaxis is the method of choice for treating severe hemophilia patients since regular clinical and radiological evaluation of joints and quality of life assessments have demonstrated good clinical outcome.19 Development of inhibitors and management of bleeds in inhibitor patients As clotting factors have become safer with a reduced risk of transmission of blood-borne pathogens, the development of inhibitory antibodies to the transfused clotting factor has become the most serious treatment complication, with a cumulative incidence up to ~30% in previously untreated patients with severe hemophilia A with first generation and second generation rFVIII.20-23 While the risk | 32 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 of inhibitor development is partly determined by the specific underlying mutation and severity of the deficiency, concerns remain about the relative immunogenicity of various types of concentrates. In Europe, two well-documented outbreaks of inhibitors in low risk patients followed the introduction of modified plasma-derived FVIII (pdFVIII) concentrates24-25 and a recent retrospective study continues to raise the question that pdFVIII may be less likely to lead to inhibitor development than rFVIII.26 Inhibitors are more likely to develop in severe hemophilia patients. Several variables appear to affect inhibitor development including age, ethnic origin, family history and mutation type (associated most commonly with large deletions, non sense point mutations, and intron 22 inversion). Inhibitors are classified as low titre if the level is <5 Bethesda Units (BU) and high titre if ≥5 BU. Patients with low titre and low responding inhibitors can be treated with higher doses of FVIII/FIX concentrate to saturate existing antibodies and provide available FVIII/FIX to achieve hemostasis. FVIII replacement therapy is usually ineffective in patients whose inhibitor titres exceed 5-10 BU. For these patients, bypassing agents, for example, activated prothrombin complex concentrates (APCC) or recombinant activated FVII (rFVIIa), represent effective treatment strategies for the treatment or prevention of hemorrhages. Several investigations are being carried out to further investigate the clinical usefulness of prophylactic administration of bypassing agents. Bypassing therapies FEIBA® (Baxter Healthcare, Westlake, CA, USA) is currently the only activated prothrombin complex concentrate (APCC) still available on the market. It contains activated factor X, prothrombin, factor IX, factor VII, protein C, activated factor VII, and trace amounts of FVIII.27 FEIBA® has been reported to successfully control approximately 80% of joint and soft tissue bleeds in patients with inhibitors.28-29 FEIBA® has also been shown to be effective in surgery.30 Rare thrombotic events including acute myocardial infarction have been reported with FEIBA® treatment. Because of the thrombotic risk, it has been recommended that the maximum daily dose of FEIBA® should not exceed 200 U/kg.31 Recombinant activated factor VII (rFVIIa) (NovoSeven®, NovoNordisk, Bagsvaerd, Denmark), which is structurally similar to human plasma FVIIa, has a complex mechanism of action which includes tissue factor-dependant and independent triggering of coagulation. NovoSeven® can bind to the surface of activated platelets and directly activates FX, leading to improved generation of thrombin.32 Recombinant FVIIa is effective in achieving hemo- stasis in hemophilia patients with inhibitor in ~80% of cases using 2 or 3 injections.33 Elective surgery in hemophiliacs was safely undertaken with rFVIIa therapy.34 As for APCC, infrequent thrombotic adverse events including venous thromboembolism, myocardial infarction were reported.35 Recent studies evaluating the efficacy of a single megadose of rFVIIa (>200 µg/kg) reported a significantly higher efficacy of the megadose with lower product consumption.36 A major concern for APCC and rFVIIa is the absence of a routine laboratory test for monitoring efficacy and potential thrombogenicity. Recently, global hemostasis tests such as thromboelastography and thrombin generation testing have been proposed for monitoring NovoSeven® and FEIBA® treatment. Surrogate markers of hemostatic efficacy Since inhibitor by-passing therapies control bleeding without any influence on the plasma level of FVIII-FIX, FVIII-FIX clotting activity cannot be used to monitor the response to these treatments. Thrombin generation is essential for clot formation and this thrombin generation is defective in hemophilia. Therefore, direct or indirect methods for assessing thrombin generation can theoretically be used as surrogate markers for monitoring hemophilia therapies. Recently, several groups reported the potential usefulness of thromboelastography and thrombin generation test in the evaluation of the hemostatic response to anti-hemophilic treatments. Recent developments and automation of thromboelastography facilitated its use in clinics, operating theatres and clinical laboratories. It provides a graphic representation of clot formation and fibrinolysis within 30 minutes. The main advantage of thromboelastography is that it includes the interactions between all components of blood, platelets, coagulation proteases and inhibitors, red and white cells. As blood sample clots, significant viscoelastic changes occur and resistance against movements are transmitted to the detector system and continuously registered. A trace is generated as a function of time to produce a thromboelastography curve. Sorensen et al.37 introduced 3 novel parameters using the first derivative (velocity profile) of the initial thromboelastography curve, the maximum velocity, the time to maximum velocity and the area under the velocity curve. Using a very low tissue factor concentration (~0.35 pM) and the velocity profile, they showed that thromboelastography could detect hypocoagulability in patients with severe hemophilia and demonstrated variation between patients.38 Some patients had particularly low clot firmness whereas others had results similar to patients with moderate hemophilia A. Thromboelastography has Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 3(1) | 33 | 12th Congress of the European Hematology Association also been shown to reflect the clinical efficacy of activated prothrombin complex concentrate39 and recombinant activated factor VII40 in hemophiliacs with inhibitors. In the presence of rFVIIa, the dynamics of blood coagulation was usually improved but wide inter-individual variations were observed in response to the same dose of rFVIIa. In a case report, Hayashi et al.41 showed that thromboelastography could be useful for detecting clinical resistance to by-passing therapies. These data suggest that a preadministration of different dose levels of by-passing agents could be helpful in defining the type and dosing of the drug for each patient. This concept of individualising by-passing therapy was recently confirmed by Young et al.42 who showed that thromboelastography was useful for testing the individual response of patients to APCC or rFVIIa and also for determining the minimal effective dose of the selected product. Although the principle was described many years ago43 thrombin generation assay has been recently adapted for use with a slow reacting fluorogenic substrate (Z-GGR-AMC) specific for thrombin. This allows the automatic measurement of thrombin generation in plasma containing fibrinogen/fibrin and in platelet-rich plasma.44-45 This made the method more practical and suitable for use in clinical laboratories and significantly improved accuracy. The most important parameters that can be derived from thrombin generation test (TGT) are (i) the lag time (minutes) corresponding to the initiation phase of coagulation; (ii) the Endogenous Thrombin Potential (ETP, nM.min) which quantifies the total thrombin enzymatic activity; (iii) the thrombin peak (nM) which corresponds to the maximal amount of thrombin that can be generated by the plasma sample during the thrombin burst; (iiii) the time to peak (minutes) which corresponds to the time course of the thrombin generation curve up to the maximal thrombin peak. A statistically significant correlation has been shown between plasma FVIII concentrations and ETP measured by TGT.46 Thes result obtained in PPP was later confirmed in PRP47 and in a cell based model system.48 The values of TGT parameters in severe, moderate and mild hemophiliacs using a low tissue factor concentration (1 pM) were recently published.49 A statistically significant correlation between plasmatic FVIII-FIX levels and ETP, peak and time to peak was demonstrated. In addition, independently of the FVIII-FIX plasma level, a correlation was found between severe clinical bleeding phenotype and ETP, suggesting that TGT could be used to evaluate clinical bleeding phenotype in patients with hemophilia. In vitro and ex vivo experiments demonstrated that TGT could be used for monitoring FVIII-FIX replacement therapy. It could also possibly be used for designing individual prophylactic regimens as well as for adapting clotting factor infusions in surgery. In vitro and ex vivo studies also showed that the addition or infusion of Feiba® or Novoseven® dosedependently increased TG capacity (ETP and peak) but this increase could not reach normal values.50-51 These results strongly suggest that TGT could be used for monitoring pharmacodynamics of by-passing agents and for optimising the infusion schedule. Therefore, the test might make a major contribution to the decision-making process of the most adapted by-passing therapy for the treatment of high risk severe hemophilia patients with inhibitor.52 Thromboelastography and TGT seem very promising, and might represent a tool for a novel approach to the management of hemophilia based on individual regimen design rather than a standard approach for all. Well-designed prospective multicentre studies are now required to confirm these early findings and further define correlations with clinical outcome. The development of hemophilia services – comprehensive care Comprehensive care addresses the treatment and prevention of bleeding, the long-term management of hemophilic arthropathy and other bleeding complications, the management of significant treatment complications (development of inhibitors and transfusion transmitted infections), and the psychosocial support and education required to manage the bleeding disorder. Laboratory services should support factor assays and inhibitor detection, and Comprehensive Care Centres should offer 24-hr access to both medical and laboratory expertise. Improved survival of hemophiliacs can be achieved with access to specialist care. Soucie et al.53 demonstrated that, in the USA, hemophiliacs who received their care in hemophilia centres had a lower hospital admission rate and a lower mortality than those who accessed their care outside. This data is a reminder of the importance of continued specialist services for this group of patients. With the improvement in treatment in developed countries, hospital attendances and admissions for hemophiliacs have reduced substantially over the past decades. This has led to concerns about the future provision of care since hemophilia centres have problems recruiting adequately trained physicians.54 Wider networking has been provided by a pediatric hemophilia network (PedNet) across Europe55 and a proposal has recently been made to establish a European co-operative group on hemophilia and other allied disorders.56 | 34 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Bio-engineering of improved FVIII – FIX molecules The production of coagulation factors by recombinant technology, combined with the disappointingly slow progress of gene replacement for hemophilia, has prompted the development of bio-engineered products that have been mutated to overcome their remaining therapeutic limitations. The proteins of interest are usually modified to enhance their pharmacokinetic properties and/or reduce immunogenicity. Improvement of production Improving the production of coagulation factors offers the theoretical an interest of increasing the availability of the molecules and diminishing production costs. The improvement of FVIII production was an attractive challenge since this molecule is particularly poorly processed compared to FIX and FVII.57 One of the early modifications was to produce a FVIII on the basis of a cDNA coding for a FVIII devoid of its B-domain sequence. The deletion of about 35% of the full-length cDNA increased the FVIII mRNA amounts leading to a higher secretion of the molecule.58 Transgene modifications were also realized by introducing regulatory elements. The insertion of introns 5’ of the coding sequence or within the coding sequence allowed a higher mRNA synthesis that was generally accompanied by an increase in protein secretion.59-61 Coagulation factors are complex molecules which need specific intracellular processing, and a fully active molecule requires crucial posttranslational steps. Some modifications within the molecule were introduced to facilitate this processing. A point mutation in factor VIII (F309S) facilitates the secretion of the molecule probably in relation to a modification of its interaction with the Bip chaperone.62 The reintroduction of a portion of the Bdomain in FVIII, which is the support of most of the glycosylations, was also able to favor secretion in vitro and in vivo.63 Improvement of circulating properties Once injected, the clotting factor molecules interact with their respective partners, resulting in relatively short circulating half-lives. An increase in this biological parameter would lower the frequency of infusion and at the same time improve patient quality of life. The introduction of disulfide bonds between A2 and A3 (C662–C1828 and C664– C1826) appeared to moderately improve VWFbinding affinity.64 The use of pegylated -liposomes was also proposed as factor VIII binds with a relatively high affinity to such modified compounds, resulting in prolonged bleeding-free intervals upon administration.65 Various pre-clinical approaches have supported the potential therapeutic value of FVIII modified by other means (such as polysialylation) to enhance its circulating half-life, or mutated to improve its resistance to degradation or clearance.66 The members of the LRP family were shown to be responsible for FVIII and FIX degradation.67-68 Several studies described the respective domains implicated in the interaction between the receptor and its agonists.69-70 The use of antagonists which could reproduce these domains would reduce the clearance of both molecules and prolong half-life. However, a major problem will be to specifically inhibit the clearance of factor VIII and/or factor IX without affecting the other functions of LRP.71 Improvement of the hemostatic potential Attempts to improve hemostatic potential have pursued three objectives, improve stability following activation, improve factor X activation capacity, and increase resistance to degradation. The mutant molecules will consequently possess an increased coagulant activity even at low concentrations. Soon after activation, factor VIII rapidly loses its procoagulant activity due to the dissociation of its A2 domain. Disulfide bridges were introduced between A2 and A3 domains, resulting in an increased stability following activation by thrombin.72 In whole blood clotting assays, only 10% of the factor VIII wild-type dose is needed to correct hemophilia A.73 A genetically engineered factor VIII molecule (IR8) in which the cleavage between A2 and A3 was abolished by modification of the protein sequence, also induced a prolongation of factor VIII clotting activity.74 Several mutants of FVII(a) were also created to generate a highly active bypassing agent. Two of these (K337A and M298Q) were able to correct bleeding in hemophilic mice with inhibitors at much lower doses.75 The introduction of 4 point substitutions (V158D/E296V/M298Q/K337A) in factor VIIa accelerated procoagulant and antifibrinolytic activities through enhancement of TAFI activation.76 Finally, specific antibodies were shown to improve factor Xa generation by favoring the binding of FVIIIa to FIXa and enhancing the catalytic efficiency of the tenase complex.77 A novel approach to improve coagulation involves heparin-like sulfated polysaccharides. Fucoidan was shown to inhibit TFPI, improve clotting time of human hemophilia A and B plasmas as well as hemostasis in vivo in mice with hemophilia A or B.78 Synthetic activated protein C inhibitors may also be considered as adjuvants for hemophilia treatment. These compounds may inhibit FVa inactivation by activated protein C and prolong FVa functional activity in the prothrombinase complex. When evaluated in a synthetic coagulation proteome Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 3(1) | 35 | 12th Congress of the European Hematology Association model, one inhibitor partially compensated for the absence of FVIII.79 Modulation of the immune response The mechanisms underlying the immune response, particularly those involved in the anti-factor VIII response, are the subject of intense investigation. The generation of an immune response requires a series of complex interactions between antigen presenting cells, B and T-lymphocytes.80-81 Different options can therefore be taken to alter the immune response. These are the decrease of factor VIII immunogenicity, the differential recognition of factor VIII molecule by already existing antibodies, and the efficiency of the immune response. Different mouse models recreating the different types of hemophilia (CRM+ and CRM-) have been generated with the aim of studying the immune response.82-84 The interest of such models is reinforced by the fact that the mouse immune response against factor VIII seems relatively close to that of humans. The most direct and simple way to modulate this response is to induce tolerance to factor VIII, using oral or nasal routes of administration.85 This approach would nevertheless require large amounts of antigen for an efficient induction of tolerance in humans. The depletion of specific B-cells or T-cells can also be envisaged, and the use of rituximab, a humanized monoclonal antibodies directed against CD20, gave promising results in small series of patients suffering from acquired hemophilia. The potential usefulness of this drug in congenital hemophilia still needs further investigation. T-cells are another target of choice, and by blocking the crosstalk mediated by the CD40/CD40L, several groups were able to induce a short term but significant reduction in the primary immune response to human factor VIII in mouse models.86-88 Alteration of factor VIII immunogenicity Considering that the porcine factor VIII was less immunogenic than its human counterpart, a group of investigators initiated a systematic substitution of functional sequences of human factor VIII by porcine counterparts, located mainly in the A2 and C2 domains.89-90 Porcine FVIII is also a potentially useful therapeutic agent because of its low crossreactivity with many inhibitors. Recombinant porcine FVIII is undergoing clinical trials in inhibitor patients. Adjuvants protecting factor VIII As the domains recognized by the antibodies are now partially identified, the co-injection of factor VIII in the presence of mimetic peptides can also be envisaged, though those peptides probably have to be modified to enhance their in vivo capacities.80 Another approach used anti-idiotypic antibodies raised against a potent anti-factor VIII antibody (mAbBO2C11). These anti-idiotypic antibodies were shown to inhibit the anti-FVIII inhibitory effect in hemophilia mice.91 Conclusion In the last 30 years, hemophilia therapy has improved dramatically while complications of this crippling disease have significantly decreased through the development of safe clotting factor concentrates, prophylaxis therapy and corrective surgical interventions. Bio-engineered recombinant factor concentrates with longer half-life, higher potency and less immunogenicity will probably be available earlier than gene therapy. These achievements will significantly improve overall compliance therapy, while in the meantime, optimization of the current treatment options towards a more individualised therapy will probably decrease costs and improve patient quality of life. However, these technological achievements should not hide the disparity in the availability of coagulation factor concentrates worldwide since it is estimated that > 75% of the world population receives either inadequate treatment or no treatment at all. One potential solution could come from transgenic animals. The mammary glands of livestock can generate a very high concentration of secreted proteins. Transgenic pigs can generate recombinant FIX in milk. Calculations suggest that 60 pigs could supply enough prophylaxis for all the FIX deficient patients (estimated at 3,000) in the USA.92 It is thought that the cost of these clotting factors could be much lower than that of current therapeutic molecules. References 1. Mannucci PM, Tuddenham EGD. The hemophilia - from royal genes to gene therapy. N Engl J Med 2001;344:1773-80. 2. Mannucci PM, Capitanio A, Del Ninno E, Colombo M, Pareti F, Ruggeri ZM. Asymptomatic liver disease in haemophiliacs. J Clin Pathol 1975;28:620-4. 3. Makris M, Preston FE, Triger DR, Underwood JC, Choo QL, Kuo G, et al. Hepatitis C antibody and chronic liver disease in haemophilia. Lancet 1990;335:1117-9. 4. Goedert JJ, Kessler CM, Aledort LM, Biggar RJ, Andes WA, White GC 2nd, et al. A prospective study of human immunodeficiency virus type 1 infection and the development of AIDS in subjects with hemophilia. N Engl J Med 1989;321:1141-8. 5. Ludlam CA, Powderly WG, Bozzette S, Diamond M, Koerper MA, Kulkarni R, et al. Clinical perspectives of emerging pathogens in bleeding disorders. Lancet 2006;367:252-61. 6. Gitschier J, Wood WI, Goralka TM, Wion KL, Chen EY, Eaton DH, et al. Characterization of the human factor VIII gene. Nature 1984;312:326-30. 7. Toole JJ, Knopf JL, Wozney JM, Sultzman LA, Buecker JL, Pittman DD, et al. Molecular cloning of a cDNA encoding human antihaemophilic factor. Nature 1984;312:342-7. 8. Choo KH, Gould KG, Rees DJ, Brownlee GG. Molecular cloning of the gene for human anti-haemophilic factor IX. Nature 1982;299:178-80. 9. Rodriguez-Merchan EC. Orthopedic surgery in persons with | 36 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 haemophilia. Thromb Haemost 2003;89:34-42. 10. Lofqvist T, Nilsson IM, Berntorp E, Pettersson H. Haemophilia prophylaxis in young patients-a long-term follow-up. J Intern Med 1997;241:395-400. 11. Fischer K, Van Den Berg M. Prophylaxis for severe haemophilia: clinical and economical issues. Haemophilia 2003;9:376-81. 12. Petrini P, Lindvall N, Egberg N, Blomback M. Prophylaxis with factor concentrates in preventing hemophilic arthropathy. Am J Pediatr Hematol Oncol 1991;13:280-7. 13. Fischer K, van der Bom JG, Molho P, Negrier C, MauserBunschoten EP, Roosendaal G, et al. Prophylactic versus on demand treatment strategies for severe haemophilia: a comparison of costs and long term outcome. Haemophilia 2002;8:74552. 14. Manco-Johnson MJ, Abshire TC, Brown D, et al. Initial results of a randomized, prospective trial of prophylaxis to prevent joint disease in young children with factor VIII (FVIII) deficiency. Blood 2005;106(11):6a. 15. Berntorp E, Boulyjenkov V, Brettler D, Chandy M, Jones P, Lee C, et al. Modern treatment of haemophilia. Bull World Health Organ 1995;73:691-701. 16. Ljung R, van den Berg M, Petrini P, Tengborn L, Scheibel E, Kekomaki R, et al. Port-a-Cath usage in children with haemophilia:experience of 53 cases. Acta Pediatr 1998;87:10514. 17. Journaycake JM, Quinn CT, Miller KL, Zajac JL, Buchanan GR. Catheter related deep venous thrombosis in children with hemophilia. Blood 2001;98:1727–31. 18. Fischer K, Van Den Berg M. Prophylaxis for severe haemophilia: clinical and economical issues. Haemophilia 2003;9:376-81. 19. Bohn RL, Avorn J, Glynn RJ, Choodnovskiy I, Haschemeyer R, Aledort LM. Prophylactic use of factor VIII: an economic evaluation. Thromb Haemost 1998;79:932-7. 20. Lusher JM, Arkin S, Abildgaard CF, Schwartz RS. Recombinant factor VIII for the treatment of previously untreated patients with hemophilia A. Safety, efficacy, and development of inhibitors. Kogenate Previously Untreated Patient Study Group. N Engl J Med 1993;328:453-9. 21. Bray GL, Gomperts ED, Courter S, Gruppo R, Gordon EM, Manco-Johnson M, et al. A multicenter study of recombinant factor VIII (recombinate): safety, efficacy, and inhibitor risk in previously untreated patients with hemophilia A. The Recombinate Study Group. Blood 1994;83:2428-35. 22. Lusher J, Abildgaard C, Arkin S, Mannucci PM, Zimmermann R, Schwartz L, et al. Human recombinant DNA-derived antihemophilic factor in the treatment of previously untreated patients with hemophilia A: final report on a hallmark clinical investigation. J Thromb Haemost 2004;2:574-83. 23. Kreuz W, Gill JC, Rothschild C, Manco-Johnson MJ, Lusher JM, Kellermann E, et al. Full-length sucrose-formulated recombinant factor VIII for treatment of previously untreated or minimally treated young children with severe haemophilia A: results of an international clinical investigation. Thromb Haemost 2005;93:457-67. 24. Rosendaal FR, Nieuwenhuis HK, van den Berg HM, Heijboer H, Mauser-Bunschoten EP, van der Meer J, et al. A sudden increase in factor VIII inhibitor development in multitransfused hemophilia A patients in The Netherlands. Dutch Hemophilia Study Group. Blood 1993;81:2180-6. 25. Peerlinck K, Arnout J, Di Giambattista M, Gilles JG, Laub R, Jacquemin M, et al. Factor VIII inhibitors in previously treated haemophilia A patients with a double virus-inactivated plasma derived factor VIII concentrate. Thromb Haemost 1997;77:806. 26. Goudemand J, Rothschild C, Demiguel V, Vinciguerrat C, Lambert T, Chambost H, et al. Influence of the type of factor VIII concentrate on the incidence of factor VIII inhibitors in previously untreated patients with severe hemophilia A. Blood 2006;107:46-51. 27. Turecek PL, Varadi K, Gritsch H, et al. Factor Xa and prothrombin: mechanism of action of FEIBA. Vox Sang 1999;77 (Suppl 1):72-9. 28. Hilgartner M, Aledort L, Andes A, Gill J. Efficacy ans safety of vapour heated anti-inhibitor coagulant complex in haemophilia patients. FEIBA study group. Transfusion 1990;30:626-30. 29. Negrier C, Goudemand J, Sultan Y, Bertrand M, Rothschild C, Lauroua P, and the members of the French FEIBA study group. Multicenter retrospective study on the utilization of FEIBA in France in patients with factor VIII and factor IX inhibitors. Thromb Haemost 1997;77:1113-9. 30. Tjonnfjord GE. Surgery in patients with hemophilia and inhibitors: a review of the Norwegian experience with FEIBA. Semin Hematol. 2006;43(Suppl 4):S18-21. 31. Ehrlich HJ, Henzl MJ, Gomperts ED. Safety of factor VIII bypass activity (FEIBA): 10-year compilation of thrombotic adverse events. Haemophilia. 2002;8:83-90. 32. Monroe DM, Hoffman M, Oliver JA, Roberts HR. Platelet activity of high dose factor VIIa is independent of tissue factor. Br J Haematol 1997;99:542-7. 33. Key NS, Aledort LM, Beardsley D, Cooper HA, Davignon G, Ewenstein BM, et al. Home treatment of mild to moderate bleeding episodes using recombinant activated factor VII (Novoseven) in haemophiliacs with inhibitors. Thromb Haemost 1998;80:912-8. 34. Shapiro A, Gilchrist GS, Hoots WK, Cooper HA, Gastineau DA. Prospective randomised trial of two doses of rFVIIa (Novoseven) in haemophilia patients with inhibitors undergoing surgery. Thromb Haemost 1998;80:773-8. 35. O’Connell KA, Wood JJ, Wise RP, Lozier JN, Braun MM. Thromboembolic adverse events after use of recombinant human coagulation factor VIIa. JAMA 2006;295:293-8. 36. Kavakli K, Makris M, Zulfikar B, Erhardtsen E, Abrams ZS, Kenet G, for the Novoseven trial (F7 HEAM-510) investigators. Home treatment of haemarthroses using a single dose regimen of recombinant activated factor VII in patients with haemophilia and inhibitors. A multi-centre, randomised, double-blind, cross-over trial. Thromb Haemost 2006;95:600-5. 37. Sorensen B, Johansen P, Christiansen K, Woelke M, Ingerslev J. Whole blood coagulation thrombelastographic profiles employing minimal tissue factor activation. J Thromb Haemost 2003;1:551-8. 38. Ingerslev J, Poulsen LH, Sorensen B. Potential role of the dynamic properties of whole blood coagulation in assessment of dosage requirements in haemophilia. Haemophilia 2003;9:348-52. 39. Sorensen B, Ingerslev J. A direct thrombin inhibitor studied by dynamic whole blood clot formation. Haemostatic response to ex-vivo addition of recombinant factor VIIa or activated prothrombin complex concentrate. Thromb Haemost 2006 ;96:446-53. 40. Sorensen B, Ingerslev J. Whole blood clot formation phenotypes in hemophilia A and rare coagulation disorders. Patterns of response to recombinant factor VIIa. J Thromb Haemost 2004;2:102-10. 41. Hayashi T, Tanaka I, Shima M, Yoshida K, Fukuda K, Sakurai Y, et al. Unresponsiveness to factor VIII inhibitor bypassing agents during haemostatic treatment for life-threatening massive bleeding in a patient with haemophilia A and a high responding inhibitor. Haemophilia. 2004;10:397-400. 42. Young G, Blain R, Nakagawa P, Nugent DJ. Individualization of bypassing agent treatment for haemophilic patients with inhibitors utilizing thromboelastography. Hemophilia 2006;12: 598-604. 43. Pitney WR, Dacie JV. A simple method of studying the generation of thrombin in recalcified plasma. Application in the investigation of haemophilia. J Clin Path 1953;6:9-14. 44. Hemker HC, Willems GM, Beguin S. A computer assisted method to obtain the prothrombin activation velocity in whole plasma independent of thrombin decay processes. Thromb Haemost 1986;56:9-17. 45. Hemker HC, Giesen PLA, Ramjee M, Wagenvoord R, Beguin S. The thrombogram: monitoring thrombin generation in platelet rich plasma. Thromb Haemost 2000;83:589-91. 46. Chantarangkul V, Clerici M, Bressi C, Giesen PL, Tripodi A. Thrombin generation assessed as endogenous thrombin potential in patients with hyper-or hypo-coagulability. Haematologica 2003;88:547-54. 47. Siegemund T, Petros S, Siegemund A, Scholz U, Engelmann L. Thrombin generation in severe haemophilia A and B: the endogenous thrombin potential in platelet-rich plasma. Thromb Haemost 2003;90:781-6. 48. Allen GA, Wolberg AS, Oliver JA, Hoffman M, Roberts HR, Monroe DM. Impact of procoagulant concentration on rate, peak and total thrombin generation in a model system. J Thromb Haemost 2004;2:402-13. 49. Dargaud Y, Beguin S, Lienhart A, Al Dieri R, Trzeciak C, Bordet JC, et al. Evaluation of thrombin generating capacity in plasma from patients with hemophilia A and B. Thromb Haemost 2005;93:475-80. 50. Varadi K, Negrier C, Berntorp E, Astermark J, Bordet JC, Morfini M, et al. Monitoring the bioavailability of FEIBA with a thrombin generation assay. J Thromb Haemost 2003;1:237480. 51. Dargaud Y, Bordet JC, Baglin T et al. Monitoring of FVIII-FIX by-passing agents by calibrated automated thrombin generation test. Haemophilia 2006;12 (suppl 2):376a. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 3(1) | 37 | 12th Congress of the European Hematology Association 52. Dargaud Y, Lienhart A, Meunier S, Hequet O, Chavanne H, Chamouard V, Marin S, et al. Major surgery in a severe haemophilia A patient with high titre inhibitor: use of the thrombin generation test in the therapeutic decision. Haemophilia 2005;11:552-8. 53. Soucie JM, Nuss R, Evatt B, Abdelhak A, Cowan L, Hill H, et al. Mortality among males with hemophilia: relations with source of medical care. The Hemophilia Surveillance System Project Investigators. Blood 2000;96:437–42. 54. Evatt BL, Black C, Batorova A, Street A, Srivastava A. Comprehensive care for haemophilia around the world. Haemophilia 2004;10(Suppl 4):9–13. 55. Ljung R, Aronis-Vournas S, Kurnik-Auberger K, van den Berg M, Chambost H, Claeyssens S, et al. Treatment of children with haemophilia in Europe: a survey of 20 centres in 16 countries. Haemophilia 2000;6:619-24. 56. Ludlam CA, Mannucci PM. Interdisciplinary Working Group. Proposal to establish a European Association for Hemophilia and Allied Disorders. J Thromb Haemost 2006;4:2270-1. 57. Kaufman RJ. Advances toward gene therapy for hemophilia at the millennium. Hum Gene Ther 1999;10:2091-107. 58. Pittman DD, Alderman EM, Tomkinson KN, Wang JH, Giles AR, Kaufman RJ. Biochemical, immunological, and in vivo functional characterization of B-domain-deleted factor VIII. Blood 1993;81:2925-35. 59. Jallat S, Perraud F, Dalemans W, Balland A, Dieterle A, Faure T, et al. Characterization of recombinant human factor IX expressed in transgenic mice and in derived trans-immortalized hepatic cell lines. EMBO J 1990;9:3295-301. 60. Kurachi S, Hitomi Y, Furukawa M, Kurachi K. Role of the intron I in the expression of the human factor IX gene. J Biol Chem 1995;270:5276 81. 61. Plantier JL, Rodriguez MH, Enjolras N, Attali O, Négrier C. A Factor VIII minigene comprising the truncated intron I of factor IX highly improves the in vitro production of Factor VIII. Thromb Haemost 2001;86:596-603. 62. Swaroop M, Moussalli M, Pipe SW, Kaufman RJ. Mutagenesis of a potential immunoglobulin-binding protein-binding site enhances secretion of coagulation factor VIII. J Biol Chem 1997;272:24121-4. 63. Miao HZ, Sirachainan N, Palmer L, Kucab P, Cunningham MA, Kaufman RJ, et al. Bioengineering of coagulation factor VIII for improved secretion. Blood 2004;103:3412-9. 64. Gale AJ, Radtke KP, Cunningham MA, Chamberlain D, Pellequer JL, Griffin JH. Intrinsic stability and functional properties of disulfide bond-stabilized coagulation factor VIIIa variants. J Thromb Haemost 2006;4:1315-22. 65. Spira J, Plyushch OP, Andreeva TA, Andreev Y. Prolonged bleeding-free period following prophylactic infusion of recombinant factor VIII (Kogenate(R) FS) reconstituted with pegylated liposomes. Blood 2006;108:3668-73. 66. Pipe SW. The promise and challenges of bioengineered recombinant clotting factors. J Thromb Haemost 2005;3:1692-701. 67. Lenting PJ, Neels JG, van den Berg BM, Clijsters PP, Meijerman DW, Pannekoek H, et al. The light chain of factor VIII comprises a binding site for low density lipoprotein receptor-related protein. J Biol Chem 1999;274:23734-9. 68. Saenko EL, Yakhyaev AV, Mikhailenko I, Strickland DK, Sarafanov AG. Role of the low density lipoprotein-related protein receptor in mediation of factor VIII catabolism. J Biol Chem 1999;274:37685-92. 69. Bovenschen N, Boertjes RC, van Stempvoort G, Voorberg J, Lenting PJ, Meijer AB, et al. Low density lipoprotein receptorrelated protein and factor IXa share structural requirements for binding to the A3 domain of coagulation factor VIII. J Biol Chem 2003;278:9370-7. 70. Sarafanov AG, Makogonenko EM, Pechik IV, Radtke KP, Khrenov AV, Ananyeva NM, et al. Identification of coagulation factor VIII A2 domain residues forming the binding epitope for low-density lipoprotein receptor-related protein. Biochemistry 2006;45:1829-40. 71. Strickland DK, Medved L. Low-density lipoprotein receptorrelated protein (LRP)-mediated clearance of activated blood coagulation co-factors and proteases: clearance mechanism or regulation. J Thromb Haemost 2006;4:1484-6. 72. Gale AJ, Pellequer JL. An engineered interdomain disulfide bond stabilizes human blood coagulation factor VIIIa. J Thromb Haemost 2003;1:1966-71. 73. Radtke KP, Griffin JH, Riceberg J, Gale AJ. Disulfide bond-stabilized factor VIII has prolonged factor VIIIa activity and improved potency in whole blood clotting assays. J Thromb Haemost 2007;5:102-8. 74. Pipe SW, Kaufman RJ. Characterization of a genetically engineered inactivation-resistant coagulation factor VIIIa. Proc Natl Acad Sci USA 1997;94:11851–6. 75. Tranholm M, Kristensen K, Kristensen AT, Pyke C, Rojkjaer R, Persson E. Improved hemostasis with superactive analogs of factor VIIa in a mouse model of hemophilia A. Blood 2003;102:3615–20. 76. Lisman T, de Groot PG, Lambert T, Rojkjaer R, Persson E. Enhanced in vitro procoagulant and antifibrinolytic potential of superactive variants of recombinant factor VIIa in severe hemophilia A. J Thromb Haemost 2003;1:2175–8. 77. Kerschbaumer RJ, Riedrich K, Kral M, Varadi K, Dorner F, Rosing J, et al. An antibody specific for coagulation factor IX enhances the activity of the intrinsic factor X-activating complex. J Biol Chem 2004;279:40445-50. 78. Liu T, Scallan CD, Broze GJ Jr, Patarroyo-White S, Pierce GF, Johnson KW. Improved coagulation in bleeding disorders by Non-Anticoagulant Sulfated Polysaccharides (NASP). Thromb Haemost 2006;95:68-76. 79. Butenas S, Orfeo T, Kalafatis M, Mann KG. Peptidomimetic inhibitors for activated protein C: implications for hemophilia management. J Thromb Haemost 2006;4:2411-6. 80. Lavigne-Lissalde G, Schved JF, Granier C, Villard S. Anti-factor VIII antibodies: a 2005 update. Thromb Haemost. 2005;94:7609. 81. Lillicrap D. The role of immunomodulation in the management of factor VIII inhibitors. Hematology Am Soc Hematol Educ Program 2006;421-5. 82. Bi L, Lawler AM, Antonarakis SE, High KA, Gearhart JD, Kazazian HH Jr. Targeted disruption of the mouse factor VIII gene produces a model of haemophilia A. Nat Genet 1995;10:119-21. 83. Bril WS, van Helden PM, Hausl C, Zuurveld MG, Ahmad RU, Hollestelle MJ, et al. Tolerance to factor VIII in a transgenic mouse expressing human factor VIII cDNA carrying an Arg(593) to Cys substitution. Thromb Haemost 2006;95:341-7. 84. Jin DY, Zhang TP, Gui T, Stafford DW, Monahan PE. Creation of a mouse expressing defective human factor IX. Blood 2004;104:1733–9. 85. Rawle FE, Pratt KP, Labelle A, Weiner HL, Hough C, Lillicrap D. Induction of partial immune tolerance to factor VIII through prior mucosal exposure to the factor VIII C2 domain. J Thromb Haemost 2006;4:2172-9. 86. Qian J, Collins M, Sharpe AH, Hoyer LW. Prevention and treatment of factor VIII inhibitors in murine hemophilia A. Blood 2000;95:1324-9. 87. Reipert BM, Sasgary M, Ahmad RU, Auer W, Turecek PL, Schwarz HP. Blockade of CD40/CD40 ligand interactions prevents induction of factor VIII inhibitors in hemophilic mice but does not induce lasting immune tolerance. Thromb Haemost 2001;86:1345-52. 88. Rossi G, Sarkar J, Scandella D. Long-term induction of immune tolerance after blockade of CD40-CD40L interaction in a mouse model of hemophilia A. Blood 2001;97:2750-7. 89. Healey JF, Lubin IM, Nakai H, Saenko EL, Hoyer LW, Scandella D, Lollar P. Residues 484-508 contain a major determinant of the inhibitory epitope in the A2 domain of human factor VIII. J Biol Chem 1995;270:14505-9. 90. Healey JF, Barrow RT, Tamim HM, Lubin IM, Shima M, Scandella D, et al. Residues Glu2181-Val2243 contain a major determinant of the inhibitory epitope in the C2 domain of human factor VIII. Blood 1998;92:3701-9. 91. Gilles JG, Grailly SC, De Maeyer M, Jacquemin MG, VanderElst LP, Saint-Remy JM. In vivo neutralization of a C2 domain-specific human anti-Factor VIII inhibitor by an antiidiotypic antibody. Blood 2004;103:2617-23. 92. Van Cott KE, Monahan PE, Nichols TC, Velander WH. Haemophilic factors produced by transgenic livestock: abundance that can enable alternative therapies worldwide. Haemophilia 2004;10 (Suppl. 4):70-6. | 38 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Hemostasis Gene therapy for hemophilia M.K.L. Chuah T. VandenDriessche Center for Transgene Technology and Gene Therapy, Flanders Institute of Biotechnology (VIB) University of Leuven, Leuven, Belgium Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:39-44 t is widely expected that improved gene therapy approaches will produce new treatments and cures for a wide range of diseases including those involving cardiovascular and hemostatic systems, cancer, diabetes, infections and autoimmune disorders. Convincing evidence continues to emerge from clinical trials that gene therapy is effective for patients suffering from a wide range of diseases.1-4 Nevertheless, gene therapy has also faced a number of setbacks and there have been concerns regarding the safety of some gene delivery approaches.5,6 Fortunately, these obstacles can be overcome. Over the past 15 years, hemophilia has become one of the most studied disease models for gene therapy. This is because a single gene defect is responsable and even a slight increase in plasma factor VIII (FVIII) or factor IX (FIX) levels can already convert a severe to a moderate phenotype. Although protein substitution therapy has significantly improved patient quality of life, it cannot be considered a cure and the risk of spontaneous bleeds remains. Furthermore, the implementation of prophylactic regimens is prohibitively expensive. This limits its widespread use and further justifies the search for a cure or novel cost-effective therapies. The development of gene therapy for hemophilia not only constitutes an important priority in its own right but also offers opportunities for the application of new gene therapy approaches for many different disease targets. This review summarizes the most recent developments in the field of gene therapy for the treatment of these inherited bleeding disorders. I Lentiviral and retroviral vectors Retroviral vectors were among the first vectors ever to be used successfully in clinical gene therapy trials, demonstrating effective long-term correction of severe, potentially lethal hereditary diseases.1,2 Lentiviral vectors have only recently been explored in the clinic for the treatment of HIV-AIDS7 and β-thalassemia.8 The main distinction between traditional retroviral vectors derived from MLV (murine leukemia virus) and lentiviral vectors (derived from HIV) is that lentiviral vectors are capable of delivering their genetic cargo into both dividing and non-dividing cells, whereas non-dividing cells are refractory to MLV transduction. There are several advantages for using these type of vectors for gene therapy of hereditary disorders, including the hemophilias. Retroviral and lentiviral vectors integrate stably into the target cell genome allowing long-term expression of the therapeutic product. Another advantage of these types of vectors is that pre-existing immunity is not a main concern since most human subjects have typically not been preexposed to the cognate wild-type viruses from which the vectors have been derived (with the exception of HIV-infected patients). These stably integrating vectors are well suited for gene transfer into dividing stem/progenitor cells, particularly hematopoietic stem/progenitor cells (HSCs). Since HSCs can both self renew and differentiate into all blood lineages, they are an attractive potential target for gene therapy of hemophilia. Initial attemps focused on the use of normally expressed or inducible promoters to drive clotting factor expression in the hematopoietic lineages.9-11 More recently, using either transgenics or lentiviral FVIII gene delivery into HSCs, it has been shown that FVIII can be synthesized in platelets.12-15 Since FVIII is stabilized by von Willebrand factor (vWF), which is normally synthesized in platelets, only small amounts of FVIII were needed to achieve phenotypic correction. Remarkably, the bleeding diathesis could even be corrected in the absence of detectable FVIII levels in the plasma. The most important advantage of this plateletdirected FVIII delivery, is that FVIII was therapeutic even in the presence of hightiter inhibitory antibodies to FVIII. Hence, Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 39 | 12th Congress of the European Hematology Association a protected releasable FVIII pool in platelets would reduce the bleeding diathesis not only in patients with hemophilia A but also in those with hemophilia A and FVIII inhibitory antibodies. While the latter group has not previously been thought to be candidates for FVIII gene therapy, these studies suggest a new approach that could be beneficial and may represent a unique advantage of this gene therapy approach over protein replacement therapy. As an alternative to megakaryocyte/platelet-directed production of clotting factors, lentiviral vectors can also be designed to express clotting factors in the erythroid lineage which resulted in therapeutic FIX levels in hemophilia B mice.16 Thus, FIX is made through the pro-normoblastic stage, and additional safety is obtained as the red cells become terminally differentiated and enucleated. However, not all of the FIX molecules produced in the erythroid lineage had undergone the necessary post-translational modifications required to generate fully functional FIX. This may prove to be a limitation in at least some ectopic cell types. These HSC-based approaches could provide patients with a self-replicating pool of stem cells that would support lifelong clotting factor expression, at least in the megakaryocyte or erythroid lineage. Nevertheless, the main limitation of using HSC-based approaches is that some level of myelo-ablative conditioning is required to facilitate stem cell engraftment. Indeed, different conditioning regimens (irradiation vs. busulfan) influenced FVIII expression levels in hemophilia A mice that received HSC which were stably transduced with retroviral vectors.17 Since short-term risks of autologous transplantation are very low and the presence of both hemophilic and acquired inhibitors can be a difficult problem in treatment management, the risk/benefit ratio for gene transfer in this setting may well be a favorable one.18 Other adult stem/progenitor cells that are a potentially attractive proposition for ex vivo gene therapy are myoblasts, that avoid the need for myeloablative conditioning. They can be readily transduced with lentiviral vectors and engineered into retrievable implants composed of non-dividing muscle fibers. This technology could be adapted for FIX delivery as a potential reversible gene therapy for hemophilia but access to the circulation is a possible limitation.19 This may explain the lack of sustained FVIII production in some of the previous gene therapy clinical trials that relied on the re-implantation of gene-engineered fibroblasts.20 In vivo gene therapy with retroviral vectors was restricted to the use of neonatal recipients since MLV can only transduce dividing hepatocytes. Retroviral delivery of FVIII or FIX genes in neonatal recipients yielded stable therapeutic clotting factor levels in hemophilic mice and dogs in the absence of any toxicity.21-23 This approach yielded some of the highest stable FVIII levels obtained by gene therapy in a large animal model. Although these findings have implications for gene therapy in pediatric subjects, the clinical implementation of this concept is not straightforward given the prevailing ethical and safety concerns of pediatric gene therapy trials. A gene therapy clinical trial had previously been conducted based on the in vivo gene delivery of retroviral-FVIII vectors in adult subjects with severe hemophilia A. However, since retroviral vectors require active cell division, the efficacy of this approach was very limited.24 Lentiviral vectors can transduce non-dividing hepatocytes.25,26 This suggested their possible use in vivo gene therapy of hemophilia in adult recipients.27-30 Lentiviral vectors derived from FIV (feline immune deficiency virus) and pseudotyped with baculovirus GP64 resulted in stable therapeutic FVIII levels without inhibitors and partial phenotypic correction.31 Systemic administration of lentiviral vectors also resulted in efficient uptake and transduction of the vector particles by antigen-presenting cells (APCs),25 consistent with the induction of a self-limiting proinflammatory response.30 Ectopic FIX expression in APCs increases the risk of developing inhibitory antibodies to FIX.32 Although this risk could be reduced by using hepatocyte-specific promoters, some residual expression in APCs still occurred resulting in immune responses that eliminated the gene-engineered hepatocytes. However, it was possible to prevent ectopic transgene expression in APCs using micro-RNA mediated gene silencing which prevented immune rejection of gene-engineered cells and consequently prolonged transgene expression.33 The development of T cell leukemia in three boys treated by ex vivo retroviral gene transfer for X-linked SCID5 along with the emergence of tumors following fetal gene transfer with lentiviral vectors34,35 raised some concerns regarding the risk of insertional oncogenesis when integrating vectors are employed. In the SCID children, insertion of the therapeutic transgene adjacent to the LMO2 transcriptional co-activator locus in the leukemic cells of all three cases has been assumed to play an important pathogenetic role and linked the gene transfer with the development of the malignancy. However, over-expression of IL2Rγc resulted in a high incidence of T-cell lymphomas in mice, transplanted with BM stem/progenitor cells transduced with a lentiviral vector encoding IL2Rγc.36 These recent results strongly suggest that the therapeutic gene itself contributed to the leukemiogenesis and may explain why leukemia has been involved in so many SCID-X1 trials compared with other trials using similar approaches. In retrospect, this may not be surprising, since IL2Rγc is directly implicated in | 40 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 the control of cell proliferation. By contrast, FVIII or FIX expression does not promote cell proliferation nor is it involved in any growth control or signaling pathways which, by default, would render gene therapy for hemophilia much safer than for some of these primary immunodeficiencies. Furthermore, the design of the vectors, particularly the use a self-inactivating vector configuration, cell-specific promoters or lentiviral instead of MLV vectors greatly reduce this potential oncogenic risk.37-40 To overcome concerns associated with random integration and insertional oncogenesis, approaches are being developed for in situ repair of defective genes by synthetic zinc finger nucleases,41 or to achieve targeted integration in defined loci in the genome using zinc finger protein-mediated targeting or phage integrases.42,43 Nevertheless, like all genebased systems, these approaches require efficient gene delivery vehicles. Similarly, the possibility of repairing the mutant mRNA in hemophilia has also shown early potential in hemophilia A mice.44 However, the trans-splicing construct required to repair the mutant mRNA must be delivered efficiently and expressed long-term in the cells that harbor the mutant clotting factor gene. Adeno-associated viral vectors AAV remains one of the preferred approaches for long-term cures of genetic diseases by virtue of its potential for long-term gene expression and reduced inflammatory properties. Encouraging preclinical studies in hemophilic mice and dogs45,46 led to two clinical trials for hemophilia B, based on either intramuscular48,49 or hepatic gene delivery of AAV2-FIX vectors.49 Administration of an AAV2-FIX vector into the skeletal muscle of hemophilia B subjects proved safe and resulted in local gene transfer and FIX expression for at least 3.7 years after vector injection. However, circulating FIX levels remained less than 1% of normal. In contrast, circulating therapeutic FIX levels (10% of normal levels) could be achieved for several weeks following liver-directed gene therapy with AAV2-FIX vectors.49 Though encouraging, FIX expression eventually declined, accompanied by transiently elevated transaminases. This was probably due to the elimination of FIX-expressing hepatocytes by an AAV2-specific cytotoxic CD8+ T-cell response. Possibly this reflects prior exposure of the trial subjects to wild-type AAV2 that naturally occurs in humans. It is of interest to note that there has not been any evidence reported of such a CD8+ T-cell response in none of the subjects enrolled in the AAV2-FIX muscle trial. This may be due to differences in vector doses or differential local immune responses.47,48 Some trial subjects also had pre-existing antibodies to AAV2 which precluded efficient gene transfer. Recent studies in mice showed that neutralizing antibody titers of as little as 1:5 can abrogate AAV transduction.50 This is an important problem for patients with hemophilia. Since these preexisting antibodies variably cross react with AAVs acquired during natural infection, accurate vector dosing in individual patients will be problematic. However, combinatorial engineering of AAV can be used to generate novel vectors that are less efficiently neutralized by human antibodies and that could potentially be used for the treatment of patients with pre-existing immunity to AAV.51 This leaves gene therapists with one final obstacle to overcome which is to prolong FIX expression at therapeutic levels. This could potentially be accomplished by transient immunosuppression to prevent a cytotoxic CD8+ T-cell response. This hypothesis will be tested in a new trial, repeating the AAV2-FIX liver delivery in patients suffering from severe hemophilia B in conjunction with transient immune suppression. To overcome the limitations of using AAV2, the use of AAV vectors based on alternative serotypes has been proposed. This has been based on the following considerations: (i) most individuals are seropositive for AAV2 due to prior natural infections whereas seropositivity for some of the alternative serotypes (for example, AAV8 or AAV9) is more limited.52,53 Furthermore, antibodies directed against AAV2 show only limited cross-reactivity with AAV8 and AAV9 and vice versa;53 (ii) unlike AAV2, AAV8 does not appear to activate T cells in non-human primates due to impaired binding to and uptake by antigen-presenting cells (APCs):54 (iii) AAV8 uncoats much more rapidly than AAV2, suggesting that AAV8 capsids may be less stable than AAV2.55 The risk of inducing cytotoxic CD8+ T-cell response could therefore be reduced in gene therapy subjects when vectors based on alternative AAV serotypes vectors are employed when compared to AAV2. This may in turn increase the chances of obtaining long-term FIX expression. However, since specific AAV2 capsid peptides were identified as capable of tight binding to the subject’s HLA-B haplotype, and since these sequences are highly conserved in all primate AAVs, it is unlikely that one can engineer around these binding sites due to the polymorphic nature of HLA class I. Furthermore, even AAV8 capsids may persist for several weeks in non-human primates.56 One of the main challenges is that no animal models available show a similar response to human subjects.56,57 So it is no certain that serotype switching would be enough to overcome the cytotoxic CD8+ T-cell response. This must be tested in clinical trials. In mice, gene transfer with AAV8 or AAV9 was more efficient in the liver than in any other organ or tissue or with any other AAV serotype, including Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 41 | 12th Congress of the European Hematology Association AAV2. This makes them particularly suitable for liver-directed hemophilia gene therapy.30,47,52,53,58-65 Stable supra-physiological FIX or FVIII levels could be obtained that corrected the bleeding diathesis, which far exceeded levels obtained using AAV2. No neutralizing antibodies against transgene-endoded FIX could be detected. The stable FIX or FVIII expression is in agreement with the long-term clotting factor expression following AAV8 delivery in large animal models, including non-human primates or hemophilia dogs47,66 and further supports the hypothesis suggested several years ago that hepatic expression of clotting factor may result in immune tolerance.67 Indeed, hepatic gene delivery of FIX using AAV vectors in mice resulted in CD4+CD25+ regulatory T cell circuits that not only prevented anti-FIX antibody formation following a potent immune challenge with FIX (+ immune adjuvant) but also inhibited T-cell responses directed against the gene-engineered cells following adenoviral-FIX gene transfer.68, 69 By contrast, control mice that had not been treated with gene therapy, all developed inhibitors to the FIX protein following immunization. This strongly suggests that the risk of developing inhibitory antibodies to FIX may be lower following hepatic gene delivery than by protein substitution therapy. Although, based on their superior hepatic transduction efficiencies in mice, the use of alternative AAV serotypes has generally been proposed to achieve higher clotting factor levels in patients, this may not necessarily be the case in large animal models. Indeed, in contrast to hemophilic mice, hepatic gene transfer efficiencies and FVIII levels were similar in hemophilia A dogs, regardless of the AAV serotype used (AAV2, 6 or 8).56 This confirms there is no transduction advantage in using AAV8 over AAV2 or AAV5 vectors in non-human primates.61 62 Thus, care must be taken when translating results from rodent species to higher or larger species, since the vectorcell surface receptor interactions and affinities remain poorly understood. From a pratical point of view, this confirms the need for at least some preclinical development in nonhuman primates. Conclusions Gene transfer technologies are improving rapidly and vectors are being developed which have fewer side-effects without compromising efficacy. The success of gene therapy for hemophilia still very much depends upon the continuous development of improved vector technologies which would hopefully and ultimately lead to a cure for patients with these bleeding disorders. References 1. Aiuti A, Slavin S, Aker M, Ficara F, Deola S, Mortellaro A et al. Correction of ADA-SCID by stem cell gene therapy combined with nonmyeloablative conditioning. Science 2002;296:2410-3. 2. Hacein-Bey-Abina S, Le Deist F, Carlier F, Bouneaud C, Hue C, De Villartay JP, et al. Sustained correction of X-linked severe combined immunodeficiency by ex vivo gene therapy. N Engl J Med 2002;346:1185-93. 3. Ott MG, Schmidt M, Schwarzwaelder K, Stein S, Siler U, Koehl U, et al. Correction of X-linked chronic granulomatous disease by gene therapy, augmented by insertional activation of MDS1-EVI1, PRDM16 or SETBP1. Nat Med 2006;12:4019. 4. Mavilio F, Pellegrini G, Ferrari S, Di Nunzio F, Di Iorio E, Recchia A, et al. Correction of junctional epidermolysis bullosa by transplantation of genetically modified epidermal stem cells. Nat Med 2006;12:1397-402. 5. Hacein-Bey-Abina S, Von Kalle C, Schmidt M, McCormack MP, Wulffraat N, Leboulch P, et al. LMO2-associated clonal T cell proliferation in two patients after gene therapy for SCIDX1. Science 2003;302:415-9. 6. Raper SE, Yudkoff M, Chirmule N, Gao GP, Nunes F, Haskal ZJ, et al. A pilot study of in vivo liver-directed gene transfer with an adenoviral vector in partial ornithine transcarbamylase deficiency. Hum Gene Ther 2002;13:163-75. 7. Levine BL, Humeau LM, Boyer J, MacGregor RR, Rebello T, Lu X, et al. Gene transfer in humans using a conditionally replicating lentiviral vector. Proc Natl Acad Sci USA 2006;103:17372-7. 8. Bank A, Dorazio R, Leboulch P. A phase I/II clinical trial of beta-globin gene therapy for beta-thalassemia. Ann N Y Acad Sci 2005;1054:308-16. 9. Kootstra NA, Matsumura R, Verma IM. Efficient production of human FVIII in hemophilic mice using lentiviral vectors. Mol Ther 2003;7:623-31. 10. Vigna E, Amendola M, Benedicenti F, Simmons AD, Follenzi A, Naldini L. Efficient Tet-dependent expression of human factor IX in vivo by a new self-regulating lentiviral vector. Mol Ther 2005;11:763-75. 11. Bigger BW, Siapati EK, Mistry A, Waddington SN, Nivsarkar MS, Jacobs L, et al. Permanent partial phenotypic correction and tolerance in a mouse model of hemophilia B by stem cell gene delivery of human factor IX. Gene Ther 2006;13:11726. 12. Shi Q, Wilcox DA, Fahs SA, Weiler H, Wells CW, Cooley BC, et al. Factor VIII ectopically targeted to platelets is therapeutic in hemophilia A with high-titer inhibitory antibodies. J Clin Invest 2006;116:1974-82. 13. Shi Q, Wilcox DA, Fahs SA, Fang J, Johnson BD, Du LM, et al. Lentivirus-mediated platelet-derived factor VIII gene therapy in murine haemophilia A. J Thromb Haemost 2007;5:352-61. 14. Yarovoi HV, Kufrin D, Eslin DE, Thornton MA, Haberichter SL, Shi Q, et al. Factor VIII ectopically expressed in platelets: efficacy in hemophilia A treatment. Blood 2003;102:4006-13. 15. Yarovoi H, Nurden AT, Montgomery RR, Nurden P, Poncz M. Intracellular interaction of von Willebrand factor and factor VIII depends on cellular context: lessons from plateletexpressed factor VIII. Blood 2005;105:4674-6. 16. Chang AH, Stephan MT, Sadelain M. Stem cell-derived erythroid cells mediate long-term systemic protein delivery. Nat Biotechnol 2006;24:1017-21. 17. Moayeri M, Hawley TS, Hawley RG. Correction of murine hemophilia A by hematopoietic stem cell gene therapy. Mol Ther 2005;12:1034-42. 18. High KA. The leak stops here: platelets as delivery vehicles for coagulation factors. J Clin Invest 2006;116:1840-2. 19. Thorrez L, Vandenburgh H, Callewaert N, Mertens N, Shansky J, Wang L, et al. Angiogenesis Enhances Factor IX Delivery and Persistence from Retrievable Human Bioengineered Muscle Implants. Mol Ther 2006;14:442-51. 20. Roth DA, Tawa NE Jr., O'Brien JM, Treco DA, Selden RF. Nonviral transfer of the gene encoding coagulation factor VIII in patients with severe hemophilia A. N Engl J Med 2001;344: 1735-42. 21. VandenDriessche T, Vanslembrouck V, Goovaerts I, Zwinnen H, Vanderhaeghen ML, Collen D, et al. Long-term expression of human coagulation factor VIII and correction | 42 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. of hemophilia A after in vivo retroviral gene transfer in factor VIII- deficient mice [see comments]. Proc Natl Acad Sci USA 1999;96:10379-84. Xu L, Gao C, Sands MS, Cai SR, Nichols TC, Bellinger DA, et al. Neonatal or hepatocyte growth factor-potentiated adult gene therapy with a retroviral vector results in therapeutic levels of canine factor IX for hemophilia B. Blood 2003;101:3924-32. Xu L, Nichols TC, Sarkar R, McCorquodale S, Bellinger DA, Ponder KP. Absence of a desmopressin response after therapeutic expression of factor VIII in hemophilia A dogs with liver-directed neonatal gene therapy. Proc Natl Acad Sci USA 2005;102:6080-5. Powell JS, Ragni MV, White GC 2nd, Lusher JM, HillmanWiseman C, Moon TE, et al. Phase 1 trial of FVIII gene transfer for severe hemophilia A using a retroviral construct administered by peripheral intravenous infusion. Blood 2003;102:2038-45. VandenDriessche T, Thorrez L, Naldini L, Follenzi A, Moons L, Berneman Z, et al. Lentiviral vectors containing the human immunodeficiency virus type-1 central polypurine tract can efficiently transduce nondividing hepatocytes and antigenpresenting cells in vivo. Blood 2002;100:813-22. Follenzi A, Sabatino G, Lombardo A, Boccaccio C, Naldini L. Efficient gene delivery and targeted expression to hepatocytes in vivo by improved lentiviral vectors. Hum Gene Ther 2002;13:243-60. Park F, Ohashi K, Kay MA. Therapeutic levels of human factor VIII and IX using HIV-1-based lentiviral vectors in mouse liver. Blood 2000;96:1173-6. Stein CS, Kang Y, Sauter SL, Townsend K, Staber P, Derksen TA, et al. In vivo treatment of hemophilia A and mucopolysaccharidosis type VII using nonprimate lentiviral vectors. Mol Ther 2001;3:850-6. Park F. Correction of bleeding diathesis without liver toxicity using arenaviral-pseudotyped HIV-1-based vectors in hemophilia A mice. Hum Gene Ther 2003;14:1489-94. Vandendriessche T, Thorrez L, Acosta-Sanchez A, Petrus I, Wang L, Ma L, et al. Efficacy and safety of adeno-associated viral vectors based on serotype 8 and 9 vs. lentiviral vectors for hemophilia B gene therapy. J Thromb Haemost 2007;5:16-24. Kang Y, Xie L, Tran DT, Stein CS, Hickey M, Davidson BL, et al. Persistent expression of factor VIII in vivo following nonprimate lentiviral gene transfer. Blood 2005;106:1552-8. Follenzi A, Battaglia M, Lombardo A, Annoni A, Roncarolo MG, Naldini L. Targeting lentiviral vector expression to hepatocytes limits transgene-specific immune response and establishes long-term expression of human antihemophilic factor IX in mice. Blood 2004;103:3700-9. Brown BD, Venneri MA, Zingale A, Sergi LS, Naldini L. Endogenous microRNA regulation suppresses transgene expression in hematopoietic lineages and enables stable gene transfer. Nat Med 2006;12:585-91. Themis M, Waddington SN, Schmidt M, von Kalle C, Wang Y, Al-Allaf F, et al. Oncogenesis following delivery of a nonprimate lentiviral gene therapy vector to fetal and neonatal mice. Mol Ther 2005;12:763-71. Waddington SN, Nivsarkar MS, Mistry AR, Buckley SM, Kemball-Cook G, Mosley KL, et al. Permanent phenotypic correction of hemophilia B in immunocompetent mice by prenatal gene therapy. Blood 2004;104:2714-21. Woods NB, Bottero V, Schmidt M, von Kalle C, Verma IM. Gene therapy: therapeutic gene causing lymphoma. Nature 2006;440:1123. Montini E, Cesana D, Schmidt M, Sanvito F, Ponzoni M, Bartholomae C, et al. Hematopoietic stem cell gene transfer in a tumor-prone mouse model uncovers low genotoxicity of lentiviral vector integration. Nat Biotechnol 2006;24:687-96. Modlich U, Bohne J, Schmidt M, von Kalle C, Knoss S, Schambach A, et al. Cell-culture assays reveal the importance of retroviral vector design for insertional genotoxicity. Blood 2006;108:2545-53. Bushman FD. Integration site selection by lentiviruses: biology and possible control. Curr Top Microbiol Immunol 2002; 261:165-77. Trono D. Virology. Picking the right spot. Science 2003;300: 1670-1. Urnov FD, Miller JC, Lee YL, Beausejour CM, Rock JM, Augustus S, et al. Highly efficient endogenous human gene correction using designed zinc-finger nucleases. Nature 2005; 435:646-51. 42. Olivares EC, Hollis RP, Chalberg TW, Meuse L, Kay MA, Calos MP. Site-specific genomic integration produces therapeutic Factor IX levels in mice. Nat Biotechnol 2002;20:11248. 43. Chalberg TW, Portlock JL, Olivares EC, Thyagarajan B, Kirby PJ, Hillman RT, et al. Integration specificity of phage phiC31 integrase in the human genome. J Mol Biol 2006;357:28-48. 44. Chao H, Mansfield SG, Bartel RC, Hiriyanna S, Mitchell LG, Garcia-Blanco MA, et al. Phenotype correction of hemophilia A mice by spliceosome-mediated RNA trans-splicing. Nat Med 2003;9:1015-9. 45. Herzog RW, Yang EY, Couto LB, Hagstrom JN, Elwell D, Fields PA, et al. Long-term correction of canine hemophilia B by gene transfer of blood coagulation factor IX mediated by adeno-associated viral vector [see comments]. Nat Med 1999;5:56-63. 46. Mount JD, Herzog RW, Tillson DM, Goodman SA, Robinson N, McCleland et al. Sustained phenotypic correction of hemophilia B dogs with a factor IX null mutation by liverdirected gene therapy. Blood 2002;99:2670-6. 47. Jiang H, Pierce GF, Ozelo MC, de Paula EV, Vargas JA, Smith P, et al. Evidence of Multiyear Factor IX Expression by AAVMediated Gene Transfer to Skeletal Muscle in an Individual with Severe Hemophilia B. Mol Ther 2006;14:452-5. 48. Manno CS, Chew AJ, Hutchison S, Larson PJ, Herzog RW, Arruda VR, et al. AAV-mediated factor IX gene transfer to skeletal muscle in patients with severe hemophilia B. Blood 2003;101:2963-72. 49. Manno CS, Arruda VR, Pierce GF, Glader B, Ragni M, Rasko J, et al. Successful transduction of liver in hemophilia by AAV-Factor IX and limitations imposed by the host immune response. Nat Med 2006;12:342-7. 50. Scallan CD, Jiang H, Liu T, Patarroyo-White S, Sommer JM, Zhou S, et al. Human immunoglobulin inhibits liver transduction by AAV vectors at low AAV2 neutralizing titers in SCID mice. Blood 2006;107:1810-7. 51. Perabo L, Endell J, King S, Lux K, Goldnau D, Hallek M, et al. Combinatorial engineering of a gene therapy vector: directed evolution of adeno-associated virus. J Gene Med 2006;8:155-62. 52. Gao GP, Alvira MR, Wang L, Calcedo R, Johnston J, Wilson JM. Novel adeno-associated viruses from rhesus monkeys as vectors for human gene therapy. Proc Natl Acad Sci U S A 2002;99:11854-9. 53. Gao G, Vandenberghe LH, Alvira MR, Lu Y, Calcedo R, Zhou X, et al. Clades of Adeno-associated viruses are widely disseminated in human tissues. J Virol 2004;78:6381-8. 54. Vandenberghe LH, Wang L, Somanathan S, Zhi Y, Figueredo J, Calcedo R, et al. Heparin binding directs activation of T cells against adeno-associated virus serotype 2 capsid. Nat Med 2006;12:967-71. 55. Thomas CE, Storm TA, Huang Z, Kay MA. Rapid uncoating of vector genomes is the key to efficient liver transduction with pseudotyped adeno-associated virus vectors. J Virol 2004;78: 3110-22. 56. Jiang H, Couto LB, Patarroyo-White S, Liu T, Nagy D, Vargas JA, et al. Effects of transient immunosuppression on adeno associated virus-mediated, liver-directed gene transfer in rhesus macaques and implications for human gene therapy. Blood 2006. 57. Li H, Murphy SL, Giles-Davis W, Edmonson S, Xiang Z, Li Y, et al. Pre-existing AAV Capsid-specific CD8+ T cells are unable to eliminate AAV-transduced hepatocytes. Mol Ther 2007. 58. Grimm D, Zhou S, Nakai H, Thomas CE, Storm TA, Fuess S, et al. Preclinical in vivo evaluation of pseudotyped adenoassociated virus vectors for liver gene therapy. Blood 2003;102: 2412-9. 59. Mingozzi F, Schuttrumpf J, Arruda VR, Liu Y, Liu YL, High KA, et al. Improved hepatic gene transfer by using an adenoassociated virus serotype 5 vector. J Virol 2002;76:10497-502. 60. Sarkar R, Tetreault R, Gao G, Wang L, Bell P, Chandler R, et al. Total correction of hemophilia A mice with canine FVIII using an AAV 8 serotype. Blood 2004;103:1253-60. 61. Davidoff AM, Gray JT, Ng CY, Zhang Y, Zhou J, Spence Y, et al. Comparison of the ability of adeno-associated viral vectors pseudotyped with serotype 2, 5, and 8 capsid proteins to mediate efficient transduction of the liver in murine and nonhuman primate models. Mol Ther 2005;11:875-88. 62. Nathwani AC, Gray JT, Ng CY, Zhou J, Spence Y, Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 43 | 12th Congress of the European Hematology Association 63. 64. 65. 66. Waddington SN, et al. Self-complementary adeno-associated virus vectors containing a novel liver-specific human factor IX expression cassette enable highly efficient transduction of murine and nonhuman primate liver. Blood 2006;107:265361. Arruda VR, Xiao W. It's all about the clothing: capsid domination in the adeno-associated viral vector world. J Thromb Haemost 2007;5:12-5. Nakai H, Fuess S, Storm TA, Muramatsu S, Nara Y, Kay MA. Unrestricted hepatocyte transduction with adeno-associated virus serotype 8 vectors in mice. J Virol 2005;79:214-24. Wu Z, Asokan A, Samulski RJ. Adeno-associated virus serotypes: vector toolkit for human gene therapy. Mol Ther 2006;14:316-27. Nathwani AC, Gray JT, McIntosh J, Ng CY, Zhou J, Spence Y, et al. Safe and efficient transduction of the liver after peripheral vein infusion of self complementary AAV vector results in stable therapeutic expression of human FIX in nonhuman primates. Blood 2006. 67. Chao H, Mao L, Bruce AT, Walsh CE. Sustained expression of human factor VIII in mice using a parvovirus- based vector. Blood 2000;95:1594-9. 68. Mingozzi F, Liu YL, Dobrzynski E, Kaufhold A, Liu JH, Wang Y, et al. Induction of immune tolerance to coagulation factor IX antigen by in vivo hepatic gene transfer. J Clin Invest 2003;111:1347-56. 69. Dobrzynski E, Fitzgerald JC, Cao O, Mingozzi F, Wang L, Herzog RW. Prevention of cytotoxic T lymphocyte responses to factor IX-expressing hepatocytes by gene transferinduced regulatory T cells. Proc Natl Acad Sci USA 2006;103:4592-7. | 44 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Thrombosis Vitamin K epoxide reductase (VKORC1): pharmacogenetics and oral anticoagulation J. Oldenburg1 C.R. Müller2 M. Watzka1 1 Institute for Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany; 2 Institute for Human Genetics, Biocentre, University Würzburg Würzburg, Germany; Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:45-50 A B S T R A C T For decades coumarins have represented the most commonly prescribed drugs for therapy and prevention of thromboembolic conditions. Despite the limitations of a narrow therapeutic range, the broad variation of intra- and inter-individual drug requirement, and the relatively high incidence of bleeding complications, therapy with coumarins is rising due to aging populations in industrialised countries. The identification of the molecular target of coumarins, VKORC1, has greatly improved the understanding of coumarin treatment and introduced new perspectives for individualised and safe oral anticoagulation therapy. Mutations as well as SNPs within the VKORC1 gene have been shown to cause coumarin sensitivity and also coumarin resistance. Besides the known CYP2C9 variants that affect coumarin metabolism, the haplotype VKORC1*2 has now been recognised as a major cause of coumarin sensitivity. A frequent SNP within the VKORC1 promotor is reducing the VKORC1 enzyme activity to 50% compared with the wild type. Patients who are homozygous carriers of the VKORC1*2 allele are strongly predisposed to coumarin sensitivity. Individualized dose adaptation, can lead to a significant reduction in bleeding complications, especially in the initial coumarin saturation phase. Meanwhile, VKORC1 and CYP2C9 genotypes in combination with other known dose influencing factors like age, gender, and weight were introduced into clinical dosing algorithms. Furthermore, concomitant application of low dose vitamin K may significantly reduce intra-individual coumarin dose variation, thus improving the safety of oral anticoagulation practice. or decades, coumarins have been the most often prescribed drugs for therapy and prevention of thromboembolic conditions, all over the world. Their oral application and low cost promote their wide use. However, clinical use of coumarins is complicated by their narrow therapeutic range and wide variations in individual drug requirements result in a relatively high incidence of bleeding complications or rethrombosis.1 Nevertheless, vitamin K antagonists remain the therapy of choice in the short and long term anticoagulation treatment necessary to prevent venous thrombosis, stroke, myocardial infarction, and other thromboembolic events.2,3 Adverse effects of coumarins are potentially serious (for example, intracerebral bleeding). The risk of haemorrhagic events exceeds 10-17%, especially in the first 90 days of treatment, including 2-5% major bleedings.4 To minimise this risk, known influencing factors like weight, gender, age, and race have been used for dose determination.5,6 Furthermore, variants of CYP2C9 have F been shown to affect the warfarin metabolism.7-10 In 2004, the molecular target of coumarins, vitamin K epoxide reductase (VKORC1) was cloned and now is accessible for molecular investigation.11-12 Apart from rare mutations in this gene, VKORC1 was shown to determine coumarin dose by haplotype specific mRNA expression levels.11,13-19 Recently, new dosing algorithms have been developed which consider VKORC1 as an independent pharmacogenetic factor influencing coumarin therapy.20-24 Determining VKORC1 variants will lead to an improved prediction of the required coumarin dose and allow identification of patients prone to over-anticoagulation. Pharmacodynamics of coumarins Inhibition of vitamin K epoxide reductase activity by coumarins, including acenocoumarol, phenprocoumon, and warfarin, is the most widely-used approach to anticoagulant therapy. The four procoagulatory factors (FII, FVII, FIX and FX) require post-translational gamma Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 45 | 12th Congress of the European Hematology Association carboxylation on glutamic residues to reach full activity. Gamma carboxylation is performed by microsomal gamma carboxylase (GGCX). This enzyme requires CO2, O2, and vitamin K-hydroquinone to generate carboxy glutamic residues capable of chelating calcium ions to bind on phospholipid surfaces. The process of gamma carboxylation generates the functional clotting factors and also vitamin K epoxide. As vitamin K is needed in high molar excess compared to the modified proteins, a highly efficient and simple recycling mechanism is needed. Recently, Chu et al.25 showed that purified and reconstituted VKORC1 protein is sufficient to accomplish both the reduction of vitamin K-epoxide to vitamin K and further vitamin K to vitamin Khydroquinone. This enzyme was previously cloned independently by our laboratory and D. Stafford’s group in Chapel Hill, NC, USA.11,12 In accordance with its hydrophobic amino acid composition and enzymatic properties, a topology of three transmembrane domains connected by a large cytoplasmatic and a small lumenal loop has been proposed.26,27 A previously identified warfarin binding motif (TYA) is located within the membrane directly neighboured to the proposed redox centre (CXXC) and represents the molecular structure targeted by coumarins.28-30 Obviously, binding of coumarins close to the active centre is the mechanism of inhibition of vitamin K recycling. Shortly after cloning VKORC1, D'Andrea et al.18 showed that the median coumarin dose was greatly influenced by a single intronic polymorphism of the VKORC1 gene. By establishing complete VKORC1 haplotypes, Rieder et al. and Geisen et al.13,19 were able to demonstrate that individual haplotype composition is responsible for interindividual and interethnical coumarin dose variations. One single haplotype (VKORC1*2) was shown to determine 30-50% of coumarin dose variation. Due to a promoter SNP (VKORC1 c.-1639 G>A, rs9923231) affecting a transcription factor binding site, mRNA expression and subsequent total VKOR enzyme activity of haplotype VKORC1*2 is reduced in vitro and in vivo by approximately 30-50%.13,14 Given the type of action of this genetic variation, an almost linear dose-response relationship could be expected. This is reflected by a dose reduction of 25 and 50% when comparing homozygous VKORC1 wt, heterozygous VKORC1*2, and homozygous VKORC1*2 genotypes respectively. This coherence has been confirmed by several other studies and even interethnical differences in coumarin dosage can be explained by VKORC1 haplotypes.13,14,19 While dose-reducing haplotype VKORC1*2 is highly prevalent in patients of Asian origin (frequency up to 95%), VKORC1*2 represents approximately 15% of alleles in African populations. In European cohorts, VKORC1*2 shows a prevalence of about 40%. This population-specific distribution is reflected by low coumarin requirements in Asian, intermediate doses in European and high doses in African populations. Pharmacokinetics of coumarin metabolism Coumarins are administered as a racemic mixture of two enantiomers, for example, R-warfarin and Swarfarin. The S-enantiomer has approximately a 35-fold higher anticoagulant effect than the R-enantiomer,31,32 but generally has a more rapid clearance. Coumarins are well absorbed with a bioavailability of over 95% and a high fraction bound to plasma albumin. Elimination of coumarins is performed mainly in the liver. Warfarin and acenocoumarol are metabolised by CYP2C9 (S-enantiomers) and other CYP enzymes (R-enantiomers).33,34 Phenprocoumon metabolism is not decisively affected by this pathway being mainly eliminated via unchanged renal excretion35,36 and the following observations are therefore only relevant in part. Despite its lower potency, R-warfarin is thought to exhibit around half of the overall anticoagulant effect of racemic warfarin. This is due to the faster clearance of the more potent S-warfarin by CYP2C9 leading to twice as high R-warfarin plasma levels compared to S-warfarin.32 Because of its even more rapid metabolisation by CYP2C9, S-acenocoumarol does not contribute much to the anticoagulant effect of racemic acenocoumarol.37,38 In CYP2C9, which is the most abundant enzyme of the CYP2C family,39 several polymorphism have been associated with impaired enzyme activity (homepage of the Human Cytochrome P450 (CYP) Allele Nomenclature Committee: http://www. cypalleles.ki.se; accessed 20/01/2007). Of these, alleles CYP2C9*2 (Arg144Cys) and CYP2C9*3 (Ile359Leu) have the most clinical relevance. With a prevalence of around 15% (CYP2C9*2) and 7% (CYP2C9*3) in Caucasians, a rate of 2.5% of homozygous or compound heterozygous for these alleles can be calculated. Among other ethnic groups, the prevalence of CYP2C9*2 and CYP2C9*3 is considerably lower.40-42 Due to their reduced enzymatic activity, these alleles are associated with increased plasma levels of the S-enantiomers, resulting in a shift in R-/S-warfarin ratio. As the S-enantiomer is a more potent anticoagulant,31,32 even small changes in plasma ratio will result in pronounced effects. For example, weekly warfarin maintenance doses in patients homozygous for defective CYP2C9*3 allele were reduced to 25% of the normal dose.43 Because of its high fraction of unchanged renal excretion, phenprocoumon has a less decisive | 46 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 effect.10 Polymorphisms in CYP2C9 other than *2 or *3 have also been described to reduce coumarin dose. The rare variant CYP2C9*11 (prevalence of 2% in Africans, 0.7% in Caucasians, and probably absent in Japanese43-45 has been shown to cause warfarin and acenocoumarol sensitivity. As mentioned above, the R-enantiomers are metabolised by different enzymes of different cytochrome P450 families, for example, CYP1A2, CYP2C8, CYP3A4, or CYP3A5.34,46,47 Although several polymorphisms are known in these enzymes, a significant effect on coumarin dose has yet not been observed. However, a number of polymorphisms in genes related to vitamin K transport, vitamin K cycle, and gamma carboxylation have been shown to influence coumarin dose.48,49 Compared to the effects of VKORC1 haplotypes and variant CYP2C9 enzymes, those of ApoE, calumenin, gamma carboxylase, and microsomal epoxid hydrolase are of minor importance for coumarin dose. Coumarin resistance Partial coumarin resistance is mainly caused by homozygous combination of wt alleles in VKORC1 and CYP2C9.13,19,20 The frequency of this combination is approximately 20% in patients of Caucasian origin. Compared to the average coumarin dose, patients bearing this genetic pattern will require a mean dose elevation of approximately 50%. These patients correspond to the upper quarter of the normal range of the coumarin dose. Due to the wide difference in distribution of wt VKORC1 haplotypes among different ethnic groups, partial coumarin resistance is much less frequent in patients of Asian origin but more prevalent in Africans.13,18,19,43,50 In some cases, dose elevation is more pronounced, and may even show a complete coumarin resistance. These rare cases are explained by mutations in VKORC1.11,15-17,51,52 When comparing mutations in VKORC1 known to lead to coumarin resistance, two main mutation clusters can be identified. The first region is the third transmembrane domain which harbours the warfarin binding motif TYA at amino acids 138-14028 and the redox-motif CXXC.29,30 By changing this motif, warfarin binding is impaired and drug action is completely compromised. The second mutation cluster is within the first extramembranous loop (amino acids 31 to 100). In this loop, three highly conserved amino acid residues were shown to be essential for VKORC1 activity (Cys43, Cys51, Ser57). As the observed mutations are distant from the proposed warfarin binding site at aa 138-140 and the redox centre at aa 132-135, an simultaneous interaction of the first loop with the reactive centre and the warfarin binding site might be hypothesised. Recently, mutation Asp36Tyr was found to be common in Jewish ethnic groups of Ethiopian and European origin and associated with an increased coumarin requirement. Here, a prevalence of 15% and 4% respectively in the normal population can be observed.53 In other Israeli Jewish populations originating from North Africa and Yemen, a frequency of 0.5% was much lower.53 In recent years, sequencing projects have suggested that Asp36Tyr is present in Caucasians at an even lower level. This mutation has not yet been observed in several 400 alleles derived from the normal population. It was only observed in a single case of a partial coumarin resistant patient.13,19,51 Furthermore, Asp36Tyr is connected to the supposed ancestral wt haplotype VKORC1*1,53 which is almost absent in Caucasians and Asians (Geisen 2005). Coumarin sensitivity Partial coumarin sensitivity is a phenomenon observed in about 15% of patients of Caucasian origin. This number corresponds well with the homozygosity rate of the low expression haplotype VKORC1*2.19,20 Combined with the defective CYP2C9 alleles *2, *3, or *11, an even more pronounced effect on coumarin dose can been observed for warfarin and acenocoumarol but not phenprocoumon.20 Patients with the VKORC1*2 genotype are predisposed to low coumarin dose and are at an elevated risk of severe over-anticoagulation and subsequent bleeding complications.54-56 In particular, patients with combined CYP2C9 polymorphisms and VKORC1*2 haplotype were prone to the adverse effects of coumarins.56 Indeed, CYP2C9*3 has been identified as a major risk factor in warfarin/acenocoumarol treatment, as rapid overdosing is due to the impaired metabolism, with subsequent accumulation of the more effective S-enantiomer.38,57,58 In infrequent cases, dramatically increased coumarin sensitivity is due to mutations in exon 2 of F9. These mutations in FIX propeptide (F9: c.109G>A p.Ala37Thr and c.110C>T p.Ala37Val; nomenclature according to Human Genome Variation Society, http://www.hgvs.org/mutnomen, accessed on 20/01/2007) cause a reduced affinity of the gamma carboxylase to the factor IX precursor, leading to an isolated and dramatic decrease of FIX activity when receiving coumarins.59,60 Generally, in the absence of coumarins, the phenotype of these patients is completely normal. New dosing algorithms Meanwhile, the genotype of both VKORC1 and CYP2C9, together with other known dose influencing factors like age, gender, and weight, were intro- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 47 | 12th Congress of the European Hematology Association duced into clinical dosing algorithms and prospective studies.20-24 Similarly, all studies report on VKORC1 as the major predictor of coumarin dose, while the influence of CYP2C9 genotype on dose is lower. The combination of polymorphisms in both genes is a strong indicator for a high risk of severe over-anticoagulation.56 Therefore, patients with combined polymorphisms in particular will benefit substantially from genotype-adapted coumarin dosing, especially in the initial saturation phase.8,9,54,56 Individualised coumarin dosing may lead to a significant reduction of related complications in the initiation phase.9,56 Concomitant administration of coumarins and vitamin K A recent development which might lead to a new principle of oral anticoagulation is the concomitant administration of coumarins and vitamin K.61 While at first, application of agonist and antagonist at the same time might appear contradictory, this is a reasoned approach in oral anticoagulation. The main complications of coumarin therapy are high INRs above the therapeutical range with consecutive bleeding complications. Difficulties in controling coumarin therapy is due to many factors. There are variable vitamin K intake from food, lack of vitamin K storage, autocatalytical dependence of gamma carboxylase enzyme from vitamin K, and VKOR activity limiting the rate of vitamin K recycling. Two recently published articles strongly support this view. Schurgers et al.62 were able to demonstrate that substitution of 150 µg per day of vitamin K did not significantly change INR in oral anticoagulation in healthy volunteers. Sconce et al.63 reported on a lower daily vitamin K intake in patients with instable INR compared to patients with stable INR course. Given these observations, one could speculate that a low dose vitamin K substitution, for example 80 µg per day, could stabilise INR values within the therapeutical range and thus reduce the risk of bleeding complications under oral anticoagulation. With an incidence of 0.25% of fatal bleeding complications per treatment year, it is worthwhile to examine this hypothesis by prospective randomised studies. Very recently, first experiences with this new approach have been published by Sconce et al.64 These first data suggest improved anticoagulation stability, but cohorts were too small to draw final conclusions. Cloning of VKORC1 and a better understanding of the vitamin K cycle will eventually lead to new principles of oral anticoagulation therapy. Acknowledgements The work of J.O. was supported by grants from the Deutsche Forschungsgemeinschaft (DFG - OL 100/3-1), the Bundesministerium für Bildung und Forschung Forschungszentrum Jülich (BMBF/PTJ - 0312708E), the National Genome Research Net Cardiovascular Diseases (BMBF/DLR-01GS0424/NHK-S12T21) and Baxter Germany. References 1. Palareti G, Manotti C, D'Angelo A, Pengo V, Erba N, Moia M, et al. Thrombotic events during oral anticoagulant treatment: results of the inception-cohort, prospective, collaborative ISCOAT study: ISCOAT study group (Italian Study on Complications of Oral Anticoagulant Therapy). Thromb Haemost 1997;78:1438-43. 2. Baglin TP, Rose PE. Guidelines on oral anticoagulation. Br J Haematol 1998;101:374-87. 3. Anand SS, Yusuf S. Oral anticoagulant therapy in patients with coronary artery disease: a meta-analysis. JAMA 1999;282:2058-67. 4. Kuijer PM, Hutten BA, Prins MH, Buller HR. Prediction of the risk of bleeding during anticoagulant treatment for venous thromboembolism. Arch Intern Med 1999;159:457-60. 5. Wilkinson TJ, Sainsbury R. Evaluation of a warfarin initiation protocol for older people. Intern Med J 2003;33:465-7. 6. Kamali F, Khan TI, King BP, Frearson R, Kesteven P, Wood P, et al. Contribution of age, body size, and CYP2C9 genotype to anticoagulant response to warfarin. Clin Pharmacol Ther 2004;75:204-12. 7. Aithal GP, Day CP, Kesteven PJ, Daly AK. Association of polymorphisms in the cytochrome P450 CYP2C9 with warfarin dose requirement and risk of bleeding complications. Lancet 1999;353:717-9. 8. Higashi MK, Veenstra DL, Kondo LM, Wittkowsky AK, Srinouanprachanh SL, Farin FM, et al. Association between CYP2C9 genetic variants and anticoagulation-related outcomes during warfarin therapy. JAMA 2002;287:1690-8. 9. Visser LE, van Schaik RH, van Vliet M, Trienekens PH, De Smet PA, Vulto AG, et al.The risk of bleeding complications in patients with cytochrome P450 CYP2C9*2 or CYP2C9*3 alleles on acenocoumarol or phenprocoumon. Thromb Haemost2004;92:61-6. 10. Schalekamp T, Oosterhof M, van Meegen E, van Der Meer FJ, Conemans J, Hermans M, et al. Effects of cytochrome P450 2C9 polymorphisms on phenprocoumon anticoagulation status. Clin Pharmacol Ther 2004;76:409-17. 11. Rost S, Fregin A, Ivaskevicius V, Conzelmann E, Hörtnagel K, Pelz HJ, et al. Mutations in VKORC1 cause warfarin resistance and multiple coagulation factor deficiency type 2. Nature 2004;427:537-41. 12. Li T, Chang CY, Jin DY, Lin PJ, Khvorova A, Stafford DW. Identification of the gene for vitamin K epoxide reductase. Nature 2004;427:541-4. 13. Rieder MJ, Reiner AP, Gage BF, Nickerson DA, Eby CS, McLeod HL, et al. Effect of VKORC1 haplotypes on transcriptional regulation and warfarin dose. N Engl J Med 2005;352:2285-93. 14. Yuan HY, Chen JJ, Lee MT, Wung JC, Chen YF, Charng MJ, et al. A novel functional VKORC1 promoter polymorphism is associated with inter-individual and inter-ethnic differences in warfarin sensitivity. Hum Mol Genet 2005;14:174551. 15. Harrington DJ, Underwood S, Morse C, Shearer MJ, Tuddenham EG, Mumford AD. Pharmacodynamic resistance to warfarin associated with a Val66Met substitution in vitamin K epoxide reductase complex subunit 1.Thromb Haemost 2005;93:23-6. 16. Bodin L, Horellou MH, Flaujac C, Loriot MA, Samama MM. A vitamin K epoxide reductase complex subunit-1 (VKORC1) mutation in a patient with vitamin K antagonist resistance. J Thromb Haemost 2005;3:1533-5. 17. D'Ambrosio RL, D'Andrea G, Cafolla A, Faillace F, Margaglione M. A new vitamin K epoxide reductase complex subunit-1 (VKORC1) mutation in a patient with | 48 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. decreased stability of CYP2C9 enzyme. J Thromb Haemost 2007;5:191-3. D'Andrea G, D'Ambrosio RL, Di Perna P, Chetta M, Santacroce R, Brancaccio V, et al. A polymorphism in the VKORC1 gene is associated with an interindividual variability in the dose-anticoagulant effect of warfarin. Blood 2005;105:645-9. Geisen C, Watzka M, Sittinger K, Steffens M, Daugela L, Seifried E, et al. VKORC1 haplotypes and their impact on the inter-individual and inter-ethnical variability of oral anticoagulation. Thromb Haemost 2005;94:773-9. Sconce EA, Khan TI, Wynne HA, Avery P, Monkhouse L, King BP, et al. The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements: proposal for a new dosing regimen. Blood 2005;106:2329-33. Tham LS, Goh BC, Nafziger A, Guo JY, Wang LZ, Soong R, et al. A warfarin-dosing model in Asians that uses singlenucleotide polymorphisms in vitamin K epoxide reductase complex and cytochrome P450 2C9. Clin Pharmacol Ther 2006;80:346-55. Sconce EA, Kamali F. Appraisal of current vitamin K dosing algorithms for the reversal of over-anticoagulation with warfarin: the need for a more tailored dosing regimen. Eur J Haematol 2006;77:457-62 Wadelius M, Chen LY, Eriksson N, Bumpstead S, Ghori J, Wadelius C, et al. Association of warfarin dose with genes involved in its action and metabolism. Hum Genet 2006 Oct 18; [Epub ahead of print] Carlquist JF, Horne BD, Muhlestein JB, Lappe DL, Whiting BM, Kolek MJ, et al. Genotypes of the cytochrome p450 isoform, CYP2C9, and the vitamin K epoxide reductase complex subunit 1 conjointly determine stable warfarin dose: a prospective study. J Thromb Thrombolysis 2006;22:191-7 Chu PH, Huang TY, Williams J, Stafford DW. Purified vitamin K epoxide reductase alone is sufficient for conversion of vitamin K epoxide to vitamin K and vitamin K to vitamin KH2. Proc Natl Acad Sci USA 2006; 103:19308-13 Tie JK, Nicchitta C, von Heijne G, Stafford DW. Membrane topology mapping of vitamin K epoxide reductase by in vitro translation/cotranslocation. J Biol Chem 2005;280:1641016416. Oldenburg J, Bevans CG, Muller CR, Watzka M. Vitamin K epoxide reductase complex subunit 1 (VKORC1): the key protein of the vitamin K cycle. Antioxid Redox Signal 2006;8:347-53. Myszka DG, Swenson RP. Synthesis of the photoaffinity probe 3-(p-azidobenzyl)-4-hydroxycoumarin and identification of the dicoumarol binding site in rat liver NAD(P)H:quinone reductase (EC 1.6.99.2). J Biol Chem 1991;266:4789-97. Rost S, Fregin A, Hunerberg M, Bevans CG, Muller CR, Oldenburg J. Site-directed mutagenesis of coumarin-type anticoagulant-sensitive VKORC1: evidence that highly conserved amino acids define structural requirements for enzymatic activity and inhibition by warfarin. Thromb Haemost 2005;94:780-6. Wajih N, Sane DC, Hutson SM, Wallin R. Engineering of a recombinant vitamin K-dependent gamma-carboxylation system with enhanced gamma-carboxyglutamic acid forming capacity: evidence for a functional CXXC redox center in the system. J Biol Chem 2005;280:10540-7. Chan E, McLachlan A, O'Reilly R, Rowland M. Stereochemical aspects of warfarin drug interactions: use of a combined pharmacokinetic-pharmacodynamic model. Clin Pharmacol Ther 1994;56:286-94. Takahashi H, Echizen H. Pharmacogenetics of warfarin elimination and its clinical implications. Clin Pharmacokinet 2001;40:587-603 Hignite C, Uetrecht J, Tschanz C, Azarnoff D. Kinetics of R andS warfarin enantiomers. Clin Pharmacol Ther 1980;28:99-105. Rettie AE, Korzekwa KR, Kunze KL, Lawrence RF, Eddy AC, Aoyama T, et al. Hydroxylation of warfarin by human cDNA-expressed cytochrome P-450: a role for P-4502C9 in the etiology of (S)-warfarin-drug interactions. Chem Res Toxicol 1992;5:54-9. Toon S, Heimark LD, Trager WF, O'Reilly RA. Metabolic fate of phenprocoumon in humans. J Pharm Sci 1985;74:1037-40. Ufer M, Kammerer B, Kahlich R, Kirchheiner J, Yasar U, Brockmoller J, Rane A. Genetic polymorphisms of cytochrome P450 2C9 causing reduced phenprocoumon (S)7-hydroxylation in vitro and in vivo. Xenobiotica 2004;34:847-59. 37. Thijssen HH, Flinois JP, Beaune PH. Cytochrome P4502C9 is the principal catalyst of racemic acenocoumarol hydroxylation reactions in human liver microsomes. Drug Metab Dispos 2000;28:1284-90. 38. Thijssen HH, Drittij MJ, Vervoort LM, de Vries-Hanje JC. Altered pharmacokinetics of R- and S-acenocoumarol in a subject heterozygous for CYP2C9*3. Clin Pharmacol Ther 2001;70:292-8. 39. Lapple F, von Richter O, Fromm MF, Richter T, Thon KP, Wisser H, et al. Differential expression and function of CYP2C isoforms in human intestine and liver. Pharmacogenetics 2003;13:565-75. 40. Lee CR, Goldstein JA, Pieper JA. Cytochrome P450 2C9 polymorphisms: a comprehensive review of the in vitro and human data. Pharmacogenetics 2002;12:251-6. 41. Gage BF, Eby CS. The genetics of vitamin K antagonists. Pharmacogenomics J 2004;4:224-5. 42. Sanderson S, Emery J, Higgins J. CYP2C9 gene variants, drug dose, and bleeding risk in warfarin-treated patients: a HuGEnet systematic review and meta-analysis. Genet Med 2005;7:97-104. 43. Takahashi H, Wilkinson GR, Nutescu EA, Morita T, Ritchie MD, Scordo MG, et al. Different contributions of polymorphisms in VKORC1 and CYP2C9 to intra- and inter-population differences in maintenance dose of warfarin in Japanese, Caucasians and African-Americans. Pharmacogenet Genomics 2006;16:101-10. 44. Tai G, Farin F, Rieder MJ, Dreisbach AW, Veenstra DL, Verlinde CL, et al. In-vitro and in-vivo effects of the CYP2C9*11 polymorphism on warfarin metabolism and dose. Pharmacogenet Genomics 2005;15:475-81. 45. Allabi AC, Gala JL, Desager JP, Heusterspreute M, Horsmans Y. Genetic polymorphisms of CYP2C9 and CYP2C19 in the Beninese and Belgian populations. Br J Clin Pharmacol 2003;56:653-7. 46. Zhang Z, Fasco MJ, Huang Z, Guengerich FP, Kaminsky LS. Human cytochromes P4501A1 and P4501A2: R-warfarin metabolism as a probe. Drug Metab Dispos. 1995;23:133946. 47. Kaminsky LS, Zhang ZY. Human P450 metabolism of warfarin. Pharmacol Ther 1997;73:67-74 48. Sconce EA, Daly AK, Khan TI, Wynne HA, Kamali F. APOE genotype makes a small contribution to warfarin dose requirements. Pharmacogenet Genomics 2006;16:609-11. 49. Vecsler M, Loebstein R, Almog S, Kurnik D, Goldman B, Halkin H, et al. Combined genetic profiles of components and regulators of the vitamin K-dependent gamma-carboxylation system affect individual sensitivity to warfarin. Thromb Haemost 2006;95:205-11 50. Veenstra DL, You JH, Rieder MJ, Farin FM, Wilkerson HW, Blough DK, et al. Association of Vitamin K epoxide reductase complex 1 (VKORC1) variants with warfarin dose in a Hong Kong Chinese patient population. Pharmacogenet Genomics 2005;15:687-91. 51. Geisen C, Spohn G, Sittinger K, Rost S, Watzka M, Dimichele DM, et al. A novel mutation in the vitamin K epoxide reductase complex subunit 1 (VKORC1) causes moderately increased coumarin doses. J Thromb Haemost 2005; 3 Suppl. abstract #P0056. 52. Pelz HJ, Rost S, Hunerberg M, Fregin A, Heiberg AC, Baert K, et al. The genetic basis of resistance to anticoagulants in rodents. Genetics 2005;170:1839-47. 53. Loebstein R, Dvoskin I, Halkin H, Vecsler M, Lubetsky A, Rechavi G, et al. A coding VKORC1 Asp36Tyr polymorphism predisposes to warfarin resistance. Blood 2006; [Epub ahead of print] 54. Reitsma PH, van der Heijden JF, Groot AP, Rosendaal FR, Buller HR. A C1173T dimorphism in the VKORC1 gene determines coumarin sensitivity and bleeding risk. PLoS Med 2005;2:e312. 55. Quteineh L, Verstuyft C, Descot C, Dubert L, Robert A, Jaillon P, et al. Vitamin K epoxide reductase (VKORC1) genetic polymorphism is associated to oral anticoagulant overdose. Thromb Haemost 2005;94:690-1. 56. Schalekamp T, Brasse BP, Roijers JF, Chahid Y, van GeestDaalderop JH, et al. VKORC1 and CYP2C9 genotypes and acenocoumarol anticoagulation status: interaction between both genotypes affects overanticoagulation. Clin Pharmacol Ther 2006;80:13-22. 57. Verstuyft C, Morin S, Robert A, Loriot MA, Beaune P, Jaillon P, et al. Early acenocoumarol overanticoagulation among cytochrome P450 2C9 poor metabolizers. Pharmacogenetics Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 49 | 12th Congress of the European Hematology Association 2001;11:735-7. 58. Takahashi H, Kashima T, Nomoto S, Iwade K, Tainaka H, Shimizu T, et al. Comparisons between in-vitro and in-vivo metabolism of (S)-warfarin: catalytic activities of cDNAexpressed CYP2C9, its Leu359 variant and their mixture versus unbound clearance in patients with the corresponding CYP2C9 genotypes. Pharmacogenetics 1998;8:365-73. 59. Chu K, Wu SM, Stanley T, Stafford DW, High KA. A mutation in the propeptide of Factor IX leads to warfarin sensitivity by a novel mechanism. J Clin Invest 1996;98:1619-25. 60. Oldenburg J, Quenzel EM, Harbrecht U, Fregin A, Kress W, Muller CR, et al. Missense mutations at ALA-10 in the factor IX propeptide: an insignificant variant in normal life but a decisive cause of bleeding during oral anticoagulant therapy. Br J Haematol 1997;98:240-4. 61. Oldenburg J. Vitamin K intake and stability of oral anticoagulant treatment. Thromb Haemost 2005;93:799-800. 62. Schurgers LJ, Shearer MJ, Hamulyak K, Stocklin E, Vermeer C. Effect of vitamin K intake on the stability of oral anticoagulant treatment: dose-response relationships in healthy subjects. Blood 2004;104:2682-9. 63. Sconce E, Khan T, Mason J, Noble F, Wynne H, Kamali F. Patients with unstable control have a poorer dietary intake of vitamin K compared to patients with stable control of anticoagulation. Thromb Haemost 2005;93:872-5. 64. Sconce E, Avery P, Wynne H, Kamali F. Vitamin K supplementation can improve stability of anticoagulation for patients with unexplained variability in response to warfarin. Blood 2006 Nov 16; [Epub ahead of print]. | 50 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Thrombosis Do arterial and venous thrombosis share common risk factors? G. Lowe Division of Cardiovascular and Medical Sciences, University of Glasgow, UK Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:51-55 raditionally, arterial and venous thrombosis have been considered as separate diseases. Standard texts emphasise differences in epidemiology and risk factors, pathology, prevention and treatment. For example, recent UK advice on prescribing stresses the importance of antiplatelet drugs in the management of arterial thrombosis, and anticoagulant drugs in venous thrombosis.1 This ignores a large body of recent evidence that anticoagulant drugs have an important role in the prevention and management of arterial thrombosis, and antiplatelet drugs in the prevention of venous thrombosis.2 Such evidence strongly supports the concept that both platelets and coagulation play important and complementary roles in both arterial and venous thrombosis. This is logical, given that thrombosis is haemostasis in the wrong place;3 and haematologists have long known that platelets and coagulation play important and complementary roles in haemostasis. For example, it has been known for many years that the antiplatelet drug aspirin increases the risk of bleeding in patients with both congential (haemophilias) and acquired (for example, anticoagulant therapy) coagulation defects. As pathological and therapeutic studies are increasingly emphasising the similarities rather than the differences between arterial and venous thrombosis, so too are epidemiological studies emphasising their similarities in risk factors. Similarities in risk factors probably explain a large part of the association between arterial and venous thrombosis in epidemiological studies.2,4 This brief review highlights recent evidence from epidemiological studies on common risk factors for arterial venous thrombosis (Table 1), and suggests that clinical management of thrombosis should address the overall thrombotic risk, arterial and venous, of the individual patient. T Time At present, there is a global epidemic of thrombotic cardiovascular disease, both arterial and venous.5-7 The epidemic of coronary heart disease (CHD) was evident in industrialized countries by the midtwentieth century when a sequential study of routine necropsies in London showed that its pathological basis was not an increasing prevalence of atherosclerosis, but rather an increasing prevalence of arterial thrombosis occurring upon atherosclerotic lesions.8 The causes of this global epidemic of arterial thrombosis are mainly environmental, not genetic, as shown by the classic Framingham Study.9 This, together with other prospective epidemiological studies, established that the major risk factors are tobacco smoke exposure, arterial blood pressure and serum cholesterol. These have each now been shown to disturb arterial endothelium and predispose to atherogenesis and thrombogenesis. Other risk factors are obesity and diabetes mellitus. Applying this knowledge of lifestyle risk factors in public health and education helped to reverse the exponential increase in CHD incidence observed in industrialized countries during the later part of the twentieth century.10 Metaanalyses of both observational studies and randomised trials on the reduction in blood pressure or serum cholesterol, have established the causality of these classical risk factors.11 Socio-economic changes12 have increased the prevalence of classic CHD risk factors around the world.13 This has led to a recent expansion of the global epidemic of CHD to developing countries. CHD will continue therefore to be a major international cause of morbidity and mortality through the twenty-first century. Furthermore, the decline of CHD in developed countries is partially offset by the increasing number of arterial thrombotic events in the brain and leg.14 Along with the continuing global epidemic of arterial thrombosis, a global epidemic of venous thromboembolism was Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 51 | 12th Congress of the European Hematology Association Table 1. Risk factors for arterial and venous thrombosis. Time Exponential increases in risk 1950-1980 in developed countries; 1980-2005 in developing countries Age Increasing life expectancy, due to reduced risk of premature death from infection and undernutrition Lack of regular exercise; increased periods of immobility Epidemic in developed and developing countries, due to decreased regular exercise and high fat diet Immobility Obesity, metabolic syndrome and type 2 diabetes Cancer Increasing overall risk due to increased life expectancy, obesity, and (in developing countries) smoking Increased survival due to earlier detection and more effective treatment Prothrombotic effects of chemotherapy Pregnancy Oral oestrogens COC, HRT Infections Common acute infections, e.g. respiratory, urinary Chronic infections, e.g. HIV? Trauma Surgery Vascular catheterisation Intravenous drug self-use Haematological disorders Thrombophilias Factor V Leiden Prothrombin G20120A mutation Lupus anticoagulant Homocysteine Polycythaemias Smoking, blood pressure, cholesterol? observed in the second half of the twentieth century.5 This shows no signs of declining despite the increased use of effective antithrombotic prophylaxis in hospitalised patients at increased risk.7 This combined epidemic of arterial and venous thrombosis suggests a global increase in thrombotic tendency over time. Let us now examine the increase in common risk factors for arterial and venous thrombosis over the last fifty years. Age One likely reason for the large increase in arterial and venous thrombosis in both developed and developing countries over the last fifty years is the median age of the population. Increased life expectancy, is the main factor due largely to the reduced risk of premature death from infection and undernutrition. This is in turn largely due to a reduction in poverty and to public health measures.12 While increased life expectancy is a positive health benefit, it results in an increasing percentage of the population aged over 60 years in whom the majority of arterial and venous thrombotic events occur. There is an exponential increase in the risk of both arterial and venous thrombotic events with age.5,7,9,10 Since age is not necessarily a direct causal risk factor, possible mechanisms for this association include: cumulative effects of causal risk factors on the arterial wall (for example, tobacco-smoking, blood pressure and cholesterol); less regular exercise and increasing periods of immobility which increase venous stasis in the lower limb and hence the risk of venous thrombosis; and systemic hypercoagulability. Epidemiological studies have shown significant changes in circulating levels of coagulation factors, inhibitors and activation markers, as well as inflammatory markers, in the age range 25-74 years.15-18 In particular, between ages 60 and 79 years, there are marked increases in circulating markers of coagulation activation (fibrin D-dimer) and inflammation (C-reactive protein), which are not attributable to increases in classic cardiovascular risk factors.19 Further studies are required to establish the causes of this exponential increase in markers of systemic hypercoagulability and inflammation with increasing age. Immobility Another likely factor promoting arterial and venous thrombosis which has seen a large increase in both developed and developing countries over the last fifty years is the major decline in regular physical activity in the general population.12 Industrialisation and socio-economic changes promote immobility through the use of private transport, the long time spent sitting watching television or sitting in front of personal computer screens, and reduced regular leisure-time activity. Epidemiological studies have shown that the latter is strongly related to both the risk of arterial thrombosis, and systemic hypercoagulability and inflammation.20 As noted above, immobility also increases venous stasis in the lower limb, increasing the risk of venous thrombosis. Obesity, metabolic syndrome and type 2 diabetes The combination of decreased regular exercise, and increased commercial promotion of a high fat diet (for example, fast food) has led to a global epidemic of obesity, the associated features of the metabolic syndrome (hypertension, dyslipidemia, hyperglycemia, hyperinsulinemia), and type 2 diabetes mellitus.21 There is strong and consistent evidence from epidemiological studies that obesity, metabolic syndrome and diabetes increase the risk of arterial thrombosis.21,22 This is most probably due to their many adverse effects on the arterial wall, as well as their systemic effects on low grade inflammation, hypercoagulability and hypofibrinolysis.15-18,21-26 Many epidemiological studies have documented associations between obesity and venous thrombosis.4,7,27-31 | 52 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Recently some studies have reported that metabolic syndrome or type 2 diabetes may increase the risk of venous thrombosis, even after adjustment for measures of obesity such as body mass index.31-33 This association may again be a consequence of their systemic effects or hypercoagulability. Cancer Cancer has long been recognised as a risk factor for both arterial and venous thrombosis.34 Possible mechanisms include local effects of solid tumours on vessels (compression, invasion), immobility for venous thrombosis, and systemic hypercoagulability induced by the tumour or by treatments such as chemotherapy.34 The impact of cancer on thrombosis is increasing globally, due to increased life expectancy, obesity and, in developing countries, smoking, increased survival after diagnosis due to earlier detection and more effective treatment, and the increased use of chemotherapy. Pregrancy Pregnancy increases the risks of arterial and venous thrombosis.35 Possible mechanisms include the effects of the pregnant uterus on vessels, immobility for venous thrombosis, and systemic hypercoagulability (especially in women with thrombophilias). These also increase the risk of other pregnancy complications, perhaps due to microthrombosis.35 However, screening for thrombophilias in early pregnancy does not seem to be cost-effective.36 Combined oral contraceptives Combined oral contraceptives (COC) increase the risks of arterial and venous thrombosis.35,37 This could be due to systemic hypercoagulability. As in pregnancy, this increases the risk of thrombosis particularly in women with thrombophilias, such as factor V Leiden. This may partly explain an early increase in risk, the so-called starter effect.35,37 However, as in pregnancy screening for thrombophilias, prior to prescription of COC does not seen to be cost-effective.36 Hormone replacement therapy Oral hormone replacement therapy (HRT) increases the risks of both arterial and venous thrombosis.35,37-39 The relative risks are similar to those of COC. However, the absolute risks are higher due to the higher age of women starting HRT.38,39 Again, the most plausible mechanism is systemic hypercoagulability, which as in pregnancy and COC use, increases the risk of thrombosis particularly in women with thrombophilias, which may partly explain the starter effect.38,39 Risk increases with age and obesity, and may differ with the type of preparation.38,39 Transdermal HRT may carry a lower risk of venous thrombosis than oral HRT.38,39 While a recent analysis suggests that screening for thrombophilias prior to prescription of oral HRT may be cost-effective,36 the risks and benefits of such screening require further evaluation.39,40 Infections Acute and chronic infections increase the risk of both arterial and venous thrombosis.7,41,42 Possible mechanisms include systemic hypercoagulability, and, for venous thrombosis, immobility. Recent epidemiological studies have shown that common acute infections (for example, respiratory, urinary) increase the risk of both arterial and venous thrombosis.41,42 Also, recent reports suggest that the current global epidemic of chronic HIV infection may also be associated with an increased risk of arterial and venous thrombosis, with or without combination antiretroviral therapy.43 Further studies are required to assess these risks, and the possible antithrombotic roles of immunisations and antithrombotic therapies. Trauma and surgery Trauma and surgery are well-established risk factors for venous thrombosis7 due to immobility and systemic hypercoagulability. National guidelines emphasise the importance of prophylaxis with mechanical methods, aspirin and/or anticoagulant drugs.44,45 Thrombophilias increase the risk, but further studies are required to establish the benefits and risks of screening prior to major surgery (for example, orthopaedic).36 There is growing interest in the increased risk of arterial thrombosis following surgery, especially in patients with clinical evidence of arterial disease.46 This can be reduced by careful assessment of patients and their medications, including aspirin, prior to surgery.46 Vascular catheterisation is also a well-recognised risk factor for both arterial and venous thrombosis. Recent reports have highlighted the global epidemic of personal intravenous drug as a risk factor for both venous thrombosis47 and arterial thrombosis when arteries are accidentally punctured. Haematological disorders Congenital thrombophilias are established risk factors for venous thrombosis,40 especially during periods of increased risk such as pregnancy, COC use, HRT use and surgery (as discussed above). There has been growing interest in their association with arterial thrombosis.40,48-50 While further studies are required, recent meta-analyses suggest that the two common prothrombotic genetic mutations (factor V Leiden and the prothrombin G20120A mutation) are associated with increased arterial thrombotic risk.49,50 However, these associations are about tenfold weak- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 53 | 12th Congress of the European Hematology Association er than their associations with risk of venous thrombosis (odds ratio about 1.2-1.3, compared to 2-3).40 These genetic mutations are associated with the phenotype of resistance to activated protein C, which has recently been associated with risk of arterial thrombosis.48 Acquired thrombophilias include lupus anticoagulants,51 hyperhomocystinemia,40 and polycythemias including polycythemia vera.52 In a recent report from the European Collaboration on Lowdose Aspirin in Polycythaemia vera prospective study, neither haematocrit (below 50%, achieved in over 90% of patients) nor platelet count was associated with thrombotic events or mortality.52This study also confirmed low-dose aspirin was effective and safe in reducing the risk of thrombotic events.53 Smoking, blood pressure and serum cholesterol These are the three classic, causal risk factors for arterial thrombosis, as established in prospective epidemiological studies.9-11 Evidence-based national guidelines continue to stress the importance of smoking habit, blood pressure, and cholesterol in both risk assessment and prevention of coronary heart disease and stroke.54 The roles of smoking, blood pressure and cholesterol on the risk of arterial thrombosis are usually considered to be due to their adverse effects on the arterial wall, promoting atherosclerosis, plaque rupture and superadded arterial thrombosis. Despite epidemiological evidence that tobacco smoking, like lack of exercise, obesity, metabolic syndrome, and type 2 diabetes, is associated with a reversible hypercoagulable state,55 there is conflicting evidence from epidemiological studies on the association between smoking and risk of venous thrombosis.7,27-31 Age and obesity, major risk factors for venous thrombosis as noted above, are major potential confounders, because smokers are overall younger with an increased risk of premature death and less obese than non-smokers.27 Increased arterial blood pressure is associated with obesity and is part of the metabolic syndrome as noted above. However, in multivariate analyses including age and obesity, major factors regarding blood pressure, there is little evidence that blood pressure is associated with risk of venous thrombosis 7,27-31 or systemic hypercoagulability.23,26 The effect of reduced blood pressure reduction on the risk of venous thrombosis has not been evaluated in randomised trials. There is also little evidence that serum cholesterol is associated with the risk of venous thrombosis 7,21,31 or systemic hypercoagulability.23,26 Recently, a review of observational studies suggested that use of statins, which lower LDL and total cholesterol, was associated with a reduction in the risk of venous thrombo- sis.56 There is little evidence that statins reduce systemic hypercoagulability57 and the postulated effect of statins on the risk of venous thrombosis must still be assessed in analyses of randomised controlled trials.2 Conclusions There is increasing evidence that arterial and venous thrombosis share several cardiovascular risk factors. Furthermore, global changes in population age, immobility and obesity are increasing the likelihood that risk factors are shared. The clinical message for hematologists is that patients with arterial or venous thrombosis increasingly share risk factors. This means that clinical management of thrombosis should address the overall thrombotic risk, arterial and venous, of the individual patient. This should be considered when evaluating secondary prevention with antithrombotic therapies in discussion with the patient. Acknowledgements The author thanks the British Heart Foundation, Medical Research Council (UK), and Chief Scientist Office, Scottish Executive Health Department, for research support; and Helen Mosson for preparing the manuscript. References 1 British Medical Association and the Royal Pharmaceutical Society of Great Britain. British National Formulary, edition 51. London: BMJ Publishing Group and RPS Publishing 2006:11928. 2. Lowe GDO. Arterial disease and venous thrombosis: are they related, and if so, what should we do about it? J Thromb Haemost 2006;4:1882-5. 3. Macfarlane RG. Introduction. Br Med Bull 1977;33:183-5. 4. Agnelli G, Becattini C. Venous thromboembolism and atherosclerosis: common denominators or different diseases? J Thromb Haemost 2006;4:1886-90. 5. Hume M, Sevitt S, Thomas DP. Venous thrombosis and pulmonary embolism. Cambridge, Mass: Harvard University Press 1970. 6. Nieto FJ. Cardiovascular disease and risk factor epidemiology: a look back at the epidemic of the 20th century. Am J Publ Hlth 1999;89:292-4. 7. Heit JA. Venous thromboembolism: disease burden, outcomes and risk factors. J Thromb Haemost 2005; 3:1611-8. 8. Morris JN. Recent history of coronary disease. Lancet 1951; i:17,69-73. 9. Kannel WB, Dawber TR, Jagen A, Revotskie N, Stokes J. Factors of risk in the development of coronary heart disease – six year follow-up experience: the Framingham Study. Ann Intern Med 1961;55:332-40. 10. Kannel WB. Contributions of the Framingham Study to the conquest of coronary artery disease. Am J Cardiol 1988; 62:1109-12. 11. Lowe GDO, Danesh J, eds. Classical and emerging risk factors for cardiovascular disease. Semin Vasc Med 2002; 2:229-445. 12. Marmot M. Social determinants of health inequalities. Lancet 2005; 365:1099-104. 13. Yusuf S, Hawken S, Ounpuu S, Dans T, Avezem A, Lanas F, et al. on behalf of the INTERHEART Study Investigations. Effect of potentially modifiable risk factors associated with myocardial infarction; case control study. Lancet 2004;364:937-52. 14. Rothwell PM, Coull AJ, Silver LE, Fairhead JF, Giles MF, Lovelock CE, et al. for the Oxford Vascular Study. Populationbased study of event-rate, incidence, case fatality, and mortality for all acute vascular events in all arterial territories (Oxford Vascular Study). Lancet 2005; 366:1773-83. | 54 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 15. Lowe GDO, Rumley A, Woodward M, Morrison CE, Philippou H, Lane DA, et al. Epidemiology of coagulation factors, inhibitors and activation markers: The Third Glasgow MONICA Survey. I. Illustrative reference ranges by age, sex and hormone use. Br J Haematol 1997; 97:775-84. 16. Lowe GDO, Rumley A, Woodward M, Reid E, Rumley J. Activated protein C resistance and the FV: R506Q mutation in a random population sample: associations with cardiovascular risk factors and coagulation variables. Thromb Haemost 1999; 81:918-24. 17. Woodward M, Rumley A, Tunstall-Pedoe H, Lowe GDO. Associations of blood rheology and interleukin-6 with cardiovascular risk factors and prevalent cardiovascular disease. Br J Haematol 1999;104:246-57. 18. Woodward M, Rumley A, Lowe GDO, Tunstall-Pedoe H. Creactive protein: associations with haematological variables, cardiovascular risk factors and prevalent cardiovascular disease. Br J Haematol 2003; 121:135-41. 19. Rumley A, Emberson JR, Wannamethee SG, Lennon L, Whincup PH, Lowe GD. Effects of older age on fibrin D-dimer, C-reactive protein and other hemostatic and inflammatory variables in men aged 60-79 years. J Thromb Haemost 2006; 4:982-7. 20. Wannamethee SG, Lowe GDO, Whincup PH, Rumley A, Walker M, Lennon L. Physical activity and hemostatic and inflammatory variables in elderly men. Circulation 2002; 105:1785-90. 21. Grundy SM, Cleeman JI, Daniels SR, Donato KA, Eckel RH, Franklin BA, et al. Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circualation 2005;112:2735-52. 22. Reusch JEB. Current concepts in insulin resistance, type 2 diabetes mellitus and the metabolic syndrome. Am J Cardiol 2002;90 (Suppl):19G-26G 23. Woodward M, Lowe GDO, Rumley A, Tunstall-Pedoe H, Philippou H, Lane DA, Morrison CE. Epidemiology of coagulation factors, inhibitors and activation markers: The Third Glasgow MONICA Survey II. Relationships to cardiovascular risk factors and prevalent cardiovascular disease. Br J Haematol 1997;97:785-97. 24. Juhan-Vague I, Alessi MC, Morange PE. Hypofibrinolysis and increased PAI-1 are linked to atherothrombosis via insulin resistance and obesity. Ann Med 2000; 32:78-84. 25. Wannamethee SG, Lowe GDO, Shaper AG, Rumley A, Lennon L, Whincup PH. Insulin resistance, haemostatic and inflammatory markers and coronary heart disease risk factors in type 2 diabetes with and without coronary heart disease. Diabetologia 2004; 47:1557-65. 26. Wannamethee SG, Lowe GDO, Shaper AG, Rumley A, Lennon L, Whincup PH. The metabolic syndrome and insulin resistance: relationship to haemostatic and inflammatory markers in older non-diabetic men. Atherosclerosis 2005; 181:101-8. 27. Lowe GDO, Osborne DH, McArdle BM., Smith A, Carter DC, Forbes CD, McLaren D, Prentice CRM. Prediction and selective prophylaxis of venous thrombosis in elective gastrointestinal surgery. Lancet 1982; i:409-412. 28. Goldhaber SZ, Savage DD, Garrison RJ, et al. Risk factors for pulmonary embolism. The Framingham Study. Am J Med 1983;74:1023-8. 29. Goldhaber SZ, Grodstein F, Stampfer MJ et al. A prospective study of risk factors for pulmonary embolism in women. JAMA 1997;277:642-5. 30. Hansson PO, Eriksson H, Welin L, Svardsudd K, Wilhelmsen L. Smoking and abdominal obesity. Risk factors for VTE among middle-aged men. The study of men born in 1913. Arch Intern Med 1999; 159:1886-90. 31. Tsai A, Cushman M, Rosamond W, Heckbert S, Polak JF, Folsom AR. Cardiovascular risk factors and VTE Incidence. Arch Intern Med 2002; 162:1182-9. 32. Ageno W, Prandoni P, Romauldi E, Chirarduzzi A, Dentali F, Pesaverto R, et al. The metabolic syndrome and the risk of venous thrombosis: a case-control study. J Thromb Haemost 2006; 4:1914-8. 33. Ay C, Tengler T, Vormittag R, Simanek R, Wolfgang D, Vukovich T et al. Venous thromboembolism – a manifestation The Hematology of the metabolic syndrome. Journal/Haematologica 2007, in press. 34. Levine MN, Lee AY, Kakkar AK. From Trousseau to targeted therapy; new insights and innovations in thrombosis and cancer. J Thromb Haemost 2003; 1:1456-63. 35. Greer IA, Ginsberg J, Forbes CD (eds). Women’s Vascular Health. London: Arnold 2007. 36. Wu O, Robertson L, Twaddle S, Lowe G, Clark P, Walker I, Brenkel I, Greaves M, Langhorne P, Regan L, Greer I. Screening for thrombophilia in high-risk situations: a meta-analysis and cost-effectiveness analysis. Br J Haematol 2005; 131:80-90. 37. Rosendaal FR, van Hylckama Vlieg A, Tanis BC, Helmerhorst FM. Estrogens, progestogens and thrombosis. J Thromb Haemost 2003;1:1371-80. 38. Lowe GDO. Hormone replacement therapy and cardiovascular disease: increased risks of venous thromboembolism and stroke, and no protection from coronary heart disease. J Intern Med 2004;256:361-74. 39. Lowe GDO. Update on the cardiovascular risks of hormone replacement therapy. Women’s Health 2007; 3:87-97 40. Lowe GDO. Can haematological tests predict cardiovascular risk? The 2005 Kettle Lecture. Br J Haematol 2006; 133, 232-50. 41. Smeeth L, Thomas SL, Hall AJ, Hubbard R, Farrington P, Vallance P. Risk of myocardial infarction and stroke after acute infection or vaccination. N Engl J Med 2004; 351:2611-18. 42. Smeeth L, Cook C, Thomas S, Hall AJ, Hubbard R, Vallance P. Risk of deep vein thrombosis and pulmonary embolism after acute infection in a community setting. Lancet 2006: 367:10759. 43. Lijfering WM, ten Kate MK, Sprenger HG, van der Meer J. Absolute risk of venous and arterial thrombosis in HIV-infected patients and effects of combination antiretroviral therapy. J Thromb Haemost 2006;4:1928-30. 44. Scottish Intercollegiate Guidelines Network (SIGN). Prophylaxis of venous thromboembolism. A national clinical guideline (SIGN 62). Edinburgh: SIGN; 2002. Available at www.sign.ac.uk 45. Hirsh J, Guyatt G, Albers G, Schunemann H (eds). The seventh ACCP conference on antithrombotic and thromboytic therapy: evidence-based guidelines. Chest 2004;126 (suppl):163s-703s. 46. Scottish Intercollegiate Guidelines Network (SIGN). Stable Angina. A national clinical guideline (SIGN 96). Edinburgh: SIGN, 2007. Available at www.sign.ac.uk 47. McColl M D, Tait RC, Greer IA, Walker ID. Injecting drug use is a risk factor for deep vein thrombosis in women in Glasgow. Br J Haematol 2001;112:641-43. 48. Smith A, Patterson C, Yarnell J, Rumley A, Ben-Shlomo Y, Lowe G. Which hemostatic markers add to the predictive value of conventional risk factors for coronary heart disease and ischemic stroke? The Caerphilly Study. Circulation 2005;112:3080-7. 49. Kim RJ, Becker RC. Association between factor V Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase C677T mutations and events of the arterial circulatory system: a meta-analysis of published studies. Am Heart J 2003; 146:948-57. 50. Ye Z, Liu EHC, Higgins JPT, Keavney BD, Lowe GDO, Collins R et al. Seven haemostatic polymorphisms and coronary disease: a meta analysis comprising 66,155 cases and 91,307 controls. Lancet 2006;367:651-8. 51. Greaves M, Cohen H, Machin SJ, Mackie I, on behalf of the Haemostasis and Thrombosis Task Force of the British Committee for Standardisation in Haematology. Guidelines on the investigation and management of the antiphospholipid syndrome. Br J Haematol 2002;109:704-15. 52. Di Nitio M, Barbui T, Di Gennaro L, et al, on behalf of the European Collaboration on Low-dose Aspirin in Polycythemia vera (ECLAP) Investigators. The hematocrit and platelet target in polycythemia vera. Br J Haematol 2006; 136:249-59. 53. Landolfi R, Marchioli R, Kutti J, Gisslinger H, Tognoni G, Patrono C, et al. On behalf of the European Collaboration on Low-dose Aspirin in Polycythemia Vera Investigators. Efficacy and safety of low-dose aspirin in polycythemia vera. N Engl J Med 2004; 350:114-24. 54. Scottish Intercollegiate Guidelines Network (SIGN). Risk assessment and prevention of cardiovascular disease. A national clinical guideline (SIGN 97). Edinburgh: SIGN, 2007. Available at www.sign.ac.uk 55. Wannamethee SG, Lowe GDO, Shaper AG, Rumley A, Lennon L, Whincup PH. Association between cigarette smoking, pipe/cigar smoking, smoking cessation, and haemostatic and inflammatory markers for cardiovascular disease. Eur Heart J 2005; 26:1765-73. 56. Squizzato A, Romualdi, E, Ageno W. Why should statins prevent venous thromboembolism (VTE)? A systematic literature search and a call for action. J Thromb Haemost 2006; 4:1925-7. 57. Balk EM, Lau J, Goudas LC, Jordan HS, Kupelnick B, Kim LU et al. Effects of statins on nonlipid serum markers associated with cardiovascular disease. Ann Intern Med 2003; 139:670-82. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 55 | Thrombosis Venous thromboembolism in medical patients: stratification and prevention A P. Prandoni Department of Medical and Surgical Sciences Thromboembolism Unit University of Padua, Italy Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:56-59 B S T A C T Acute venous thromboembolism (VTE) is a serious and potentially fatal disorder. It often complicates the course of hospitalized patients but may also affect ambulatory and otherwise healthy people. While the introduction of thromboprophylactic measures has probably had an impact on the occurrence of postoperative VTE, there is an increasing awareness of the importance of medical conditions in determining thromboembolic events. Simple and clinically relevant risk assessment models are available to facilitate VTE risk assessment in hospitalized medical patients. According to international guidelines, high-risk medical patients should receive in-hospital pharmacological thromboprophylaxis with either unfractionated or low-molecular-weight heparin, unless contraindicated. Other non-surgical factors that have been associated with an increased risk of VTE disorders include cancer, air travel, inflammation, persistent elevation of D-dimer and atherosclerotic disease. Recognition of the incidence and clinical importance of thrombosis will probably encourage a more widespread use of antithrombotic prophylaxis in medical patients. cute venous thromboembolism (VTE) is a serious and potentially fatal disorder. It often complicates the course of hospitalized patients but may also affect ambulatory and otherwise healthy people. In 1884, Rudolph Virchow first proposed that thrombosis was the result of at least one of three underlying etiologic factors, vascular endothelial damage, stasis of blood flow, and hypercoagulability. In the last century, there was growing recognition that all risk factors for venous thromboembolism (VTE) reflect these underlying pathophysiologic processes and that VTE does not usually develop in their absence.1 In a review of 12,31 consecutive patients treated for VTE, 96% had at least one recognized risk factor.2 Furthermore, there is convincing evidence that risk increases in proportion to the number of predisposing factors presented.1,3 According to recent epidemiological data collected in two Swedish cities, VTE is to be expected in 1.6-1.8 per 1,000 inhabitants per year.4,5 Classic risk factors for VTE include cancer, surgery, prolonged immobilization, fractures, puerperium, paralysis, use of oral contraceptives, and the antiphospholipid antibody syndrome.1,3 These not only predispose apparently normal patients to thrombosis, but are also likely to lead to A | 56 | R this condition in people with inherited thrombophilic abnormalities.1,3 Combined genetic defects, as well as the combination of a genetic defect with one or more acquired risk factors, and the combination of two acquired risk factors, result in a risk of VTE that exceeds the sum of the separate effects of the single factors.3 This is the case of the combination of highly prevalent defects, such as factor V Leiden and prothrombin mutation, with even small risk factors such as the oral contraceptive pill, or the combination of the oral contraceptive pill with even minor surgery or injury. Most clinically recognized instances of VTE are suspected because of typical signs and symptoms in individuals who come to an outpatient clinic or hospital emergency department.1 Hospita-lization for surgery and for medical illnesses account for similar proportions of cases.6 VTE often affects ambulant and otherwise healthy individuals.7 This review focuses on old and new acquired hypercoagulable states that can be responsible of VTE disorders in both hospitalized and ambulant medical patients. Medically ill patients While the introduction of thromboprophylactic measures has probably had an Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Restricted mobility plus at least 1 risk factor of VTE* Contraindications to pharmacological thromboprophylaxis? NO Enoxaparin 4000 U, Dalteparin 5000 U, Fondaparinux 2.5 mg o.i.d or UFH 5000 U t.i.d YES Mechanical measures (IPC, GCS) * Age older than 70, active cancer, previous thromboembolism, already known thrombophilia, recent trauma or surgery, heart and/or respiratory failure, acute infectious disease, rheumatic disease, obesity, hormonal treatment; IPC: intermittent pneumatic compression; GCS: graduated compression stockings. Figure 1. Algorithm for risk stratification and implementation of thromboprophylaxis in high risk medical patients impact on the present occurrence of postoperative VTE, there is an increasing awareness of the importance of medical conditions in determining thromboembolic events, since as appropriate thromboprophylaxis is rarely administered to patients on medical wards. Three large-scale prevention studies involving over 5,500 medically ill patients have shown that 11-15% will have VTE and 4-5% will have proximal-vein thrombosis as identified by screening studies in the absence of prophylaxis.8-10 Also, the national DVT Free Registry found that 60% of patients diagnosed with an acute DVT were in the peri-hospitalization period. Approximately 60% of the cases occurred in non-surgical patients.11 Current literature highlights numerous risk factors for VTE in the medically ill patient. These clinical risk factors include increasing age, acute respiratory failure, congestive heart failure, prolonged immobility, stroke or paralysis, previous VTE, cancer and its treatment, acute infection, dehydration, hormonal treatment, varicose veins, acute inflammatory bowel disease, rheumatologic disease, and nephrotic syndrome.12,13 Patients with mostly asymptomatic proximal-vein thrombosis may carry an unexpectedly high risk of in-hospital death.14 Recent data suggest that current practice is associated with serious uncertainty leading to both the overuse and underuse of thromboprophylaxis in patients on medical wards.15 VTE can affect apparently healthy people. Besides circumstantial events, the additional risk factors for VTE that increase the thromboembolic risk in these individuals do not substantially differ from those accounting for VTE in the hospital setting. The most common are old age, varicose veins, cancer, heart failure, peripheral artery disease, and previous VTE.16,17 In this context it is interesting that obesity, smoking, and hypertension have been found to be associated with an increased VTE risk.5,18 Consensus guidelines published by the American College of Chest Physicians (ACCP) and the International Consensus Statement (ICS) recommend assessment of all hospitalized medical patients for the risk of VTE and the provision of appropriate thromboprophylaxis.19,20 Furthermore, simple and clinically relevant risk assessment models are available to facilitate VTE risk assessment.21-23 Figure 1 provides an example of risk assessment model that integrates appropriate thromboprophylactic strategies in the form of a management algorithm. Installation of computer-alert programs and electronic tools can potentially increase physicians’ use of prophylaxis,24,25 and to markedly reduce the rate of VTE arising among hospitalized patients at risk.24 Based on available information, the recently updated ACCP and ICS guidelines give a strong recommendation for thromboprophylaxis using either enoxaparin 4,000 U in one daily administration, dalteparin 5,000 U in one daily administration, unfractionated heparin 5,000 U in three daily injections in hospitalized medical patients aged > 40 with congestive heart failure or severe respiratory disease, or in medical patients who are confined to bed and have one or more risk factors for VTE, such as active cancer, acute neurological disease, infective disease, inflammatory bowel disease, rheumatic disease, previous VTE or sepsis.19,20 As an alternative, fondaparinux 2.5 mg once daily can be considered. In patients with a contraindication for pharmacological thromboprophylaxis (such as those with hemorrhagic stroke or ischemic stroke with bleeding risk), intermittent pneumatic compression, graduated elastic stockings or both should be considered. Whether thromboprophylaxis in high risk medical patients should be extended beyond the period of hospitalization remains to be demonstrated although relevant studies are ongoing. Other non-surgical causes of VTE Cancer Since Armand Trousseau’s initial observation in 1865, numerous studies have addressed the relationship between cancer and VTE. VTE is either a frequent complication in cancer patients, or sometimes acts as an epiphenomenon of a hidden cancer. In this way it offer opportunities for anticipated cancer diagnosis and treatment26 in patients with malignancy VTE represents an important cause of morbidity and mortality. It has been estimated that 1 in every 7 hospitalized cancer patients who die, do so from pulmonary embolism.27 Of these patients, 60% have Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 57 | 12th Congress of the European Hematology Association localized cancer or limited metastatic disease, which would have allowed a longer survival in the absence of the fatal PE. According to the Medicare Provider Analysis and Review Record, a database that records the primary discharge diagnosis and an additional four discharge diagnoses in the USA, the rate of initial or recurrent thromboembolism in patients with cancer well exceeds that recorded in those without malignancy, and affects cancers of virtually all body systems with a similar frequency.28 Patients with cancer have a highly increased risk of VTE in the first few months after diagnosis and in thepresence of distant metastases.29 This risk is further increased in the presence of inherited thrombophilic abnormalities.29 The real true rate of VTE in cancer patients is virtually unknown. This is due to the surprising lack of information in almost all studies dealing with the natural history of malignant diseases. However, the majority of thrombotic episodes occur spontaneously, in the absence of triggering factors that commonly account for thromboembolic complications in subjects without cancer.29 This is confirmed by the high frequency of patients with known malignancy referred to clinicians for the development of VTE.30 The most common factors that put cancer patients at a higher risk of VTE include immobilization, surgery, chemotherapy with or without adjuvant hormone therapy, and the insertion of central venous catheters.26 Among factors that are associated with a higher risk of VTE during chemotherapy are the site of cancer (namely, upper gastrointestinal or lung), prechemotherapy platelet count > 350/nL, the use of white cell growth factors, hemoglobin value lower than 10 g/dl or use of erythropoietin.31 The strong association between cancer and venous thromboembolism is further emphasized by the high rate of cancer development in patients with venous thrombosis. According to the results of the most important studies, this risk has been consistently found to be 4-5 higher as high in patients with idiopathic rather than secondary thrombosis.26 These data have recently found important confirmation in four very large, retrospective, population-based studies.32-35 Interestingly, although the risk for developing cancer was particularly high in the first six months after the diagnosis of VTE, a significant effect persisted for up to 10 years, suggesting that either a malignant disorder can induce hypercoagulability many years prior to its overt clinical development or that cancer and thrombosis share common risk factors. A recent investigation has indeed provided direct genetic evidence for the link between oncogene activation and thrombosis.36 Air travel the risks of VTE associated with long-duration air travel – the so-called economy class syndrome.1 There is a general consensus that clinically important VTE after air travel is rare. Case reports suggest that most cases of travel-related thrombosis affected people at risk because of previous VTE or other predisposing factors. Inflammation In a recent population-based case-control study, van Aken and al. showed that subjects with elevated interleukin-8 levels have an increased risk of venous thrombosis, thus giving some support to the role of inflammation in the pathogenesis of venous thrombosis.37 It is not surprising, therefore, that subjects with inflammatory bowel disorders, Behcet disease, HIV infection, and other infectious diseases exhibit an increased risk of VTE. It should be noted, however, that in a recent prospective investigation, markers of inflammation such as fibrinogen, C-reactive protein levels, or white cell count were not associated with VTE.38 D-Dimer In a recent case-control study, investigators from the Thrombophilia Leiden Study showed an interesting association between elevated levels of DDimer and the risk of venous thrombosis.39 These findings have been confirmed by those of a recent prospective investigation.40 It is quite evident that Ddimer cannot by itself represent the cause of venous thromboembolism, but should be interpreted as a marker of hypercoagulability often detectable in disease states as well as in otherwise healthy people. These studies open new interesting perspectives for future research. Atherosclerosis Although acquired and/or inherited risk factors potentially responsible for VTE are identifiable in the majority of patients, the disease remains unexplained in up to 30% of patients. Recently, an unexpected association of VTE with atherosclerosis was found.41 Also, in three cohort studies dealing with the long term follow-up of patients with VTE, those patients who had an idiopathic episode had a statistically significant and clinically relevant increased risk of atherosclerotic complications and cardiovascular events compared to patients with secondary VTE42,43 or matched control subjects.44 Although two studies failed to show an increased risk of VTE in patients with subclinical atherosclerosis.45,46 we suspect that either atherosclerotic disease may induce venous thrombosis or the two conditions share common risk factors. Recently, the popular press has drawn attention to | 58 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Conclusions VTE is a serious and potentially fatal disorder which complicates the course of hospitalized patients and may also affect ambulant and otherwise healthy people. The risk factors that predispose patients to thrombosis are numerous. Recognition of the incidence and clinical importance of thrombosis in high risk medical patients during hospitalization will probably encourage a more widespread use of antithrombotic prophylaxis in these patients. References 1 2. 3. 4. 5. 6. 7. 8. 9. 21. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. Anderson FA, Spencer FA. Risk factors for venous thromboembolism. Circulation 2003;107(Suppl. I):9-16. Anderson FA, Wheeler HB. Physicians practices in the management of venous thromboembolism: a community-wide survey. J Vasc Surg 1992;16:707-14. Rosendaal FR. Risk factors for venous thrombosis: prevalence, risk, and interaction. Semin Hematol 1997;34:171-87. Nordstrom M, Lindblad B, Berqvist D, Kjelstrom T. A prospective study of the incidence of deep-vein thrombosis within a defined urban population. J Intern Med 1992;232:155-60. Hansson PO, Welin L, Tibblin G, Eriksson H. Deep vein thrombosis and pulmonary embolism in the general population. Arch Intern Med 1997;157:1665-70. Heit JA, O'Fallon WM, Petterson TM, Lohse CM, Silverstein MD, Mohr DN, Melton LJ 3rd. Relative impact of risk factors for deep vein thrombosis and pulmonary embolism: a population-based study. Arch Intern Med 2002;162:1245-8. White RH. The epidemiology of venous thromboembolism. Circulation 2003;107(Suppl. I):4-8. Samama M, Cohen AT, Darmon JY, et al. A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. N Engl J Med 1999;341:793-800. Leizorovicz A, Cohen AT, Turpie AG, Olsson CG, Vaitkus PT, Goldhaber SZ. Randomized, placebo-controlled trial of dalteparin for the prevention of venous thromboembolism in acutely ill medical patients. Circulation 2004;110:874-9. Cohen AT, Davidson BL, Gallus AS, et al. Efficacy and safety of fondaparinux for the prevention of venous thromboembolism in older acute medical patients: randomised placebo controlled trial. BMJ 2006;332:325-9. Goldhaber SZ, Tapson VF. A prospective registry of 5,451 patients with ultrasound-confirmed deep vein thrombosis. Am J Cardiol 2004;93:259-62. Alikhan R, Cohen AT, Combe S, et al. Risk factors for venous thromboembolism in hospitalized patients with acute medical illness: analysis of the MEDENOX Study. Arch Intern Med 2004;164:963-8. Zakai NA, Wright J, Cushman M. Risk factors for venous thrombosis in medical inpatients: validation of a thrombosis risk score. J Thromb Haemost 2004;2:2156-61. Vaitkus PT, Leizorovicz A, Cohen AT, Turpie AG, Olsson CG, Goldhaber SZ. Mortality rates and risk factors for asymptomatic deep vein thrombosis in medical patients. Thromb Haemost 2005;93:76-9. Chopard P, Dorffler-Melly J, Hess U, et al. Venous thromboembolism prophylaxis in acutely ill medical patients: definite need for improvement. J Intern Med 2005;257:352-7. Cogo A, Bernardi E, Prandoni P, et al. Acquired risk factors for deep-vein thrombosis in symptomatic outpatients. Arch Intern Med 1994;154:164-8. Samama MM, for the Sirius Study Group. An epidemiologic study of risk factors for deep vein thrombosis in medical outpatients. Arch Intern Med 2000;160:3415-20. Goldhaber SZ, Grodstein F, Stampfer MJ, et al. A prospective study of risk factors for pulmonary embolism in women. JAMA 1997;277:642-5. Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism: The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004;126: 338S-400S. Nicolaides AN, Fareed J, Kakkar AK, et al. Prevention and treatment of venous thromboembolism. International Consensus Statement. Guidelines according to scientific evidence. Int Angiol 2006;25:101-61. 21. Caprini JA, Arcelus JI, Reyna JJ. Effective risk stratification of surgical and nonsurgical patients for venous thromboembolic disease. Semin Hematol 2001;38 (Suppl 5):12-9. 22. Haas SK. Venous thromboembolic risk and its prevention in hospitalised medical patients. Semin Thromb Haemost 2002;28:577-84. 23. Cohen AT, Alikhan R, Arcelus JI, et al. Assessment of venous thromboembolism risk and the benefits of thromboprophylaxis in medical patients. Thromb Haemost 2005;94:750-9. 24. Kucher N, Koo S, Quiroz R, et al. Electronic alerts to prevent venous thromboembolism among hospitalized patients. N Engl J Med 2005;352:969-77. 25. Samama MM, Dahl OE, Mismetti P, et al. An electronic tool for venous thromboembolism prevention in medical and surgical patients. Haematologica 2006;91:64-70. 26. Prandoni P, Falanga A, Piccioli A. Cancer and venous thromboembolism. Lancet Oncology 2005;6:401-10. 27. Kakkar AK, Levine M, Pinedo HM, Wolff R, Wong J. Venous thrombosis in cancer patients: insights from a frontline survey. The Oncologist 2003;8:381-8. 28. Levitan N, Dowlati A, Remick SC et al. Rates of initial and recurrent thromboembolic disease among patients with malignancy versus those without malignancy. Risk analysis using Medicare claims data. Medicine (Baltimore) 1999;78:285-91. 29. Blom JW, Doggen CJ, Osanto S, Rosendaal FR. Malignancies, prothrombotic mutations, and the risk of venous thrombosis. JAMA 2005;293:715-22. 30. Otten HM, Prins MH. Venous thromboembolism and occult malignancy. Tromb Res 2001;102:V187-94. 31. Khorana AA, Francis CW, Culakova E, Lyman GH. Risk factors for chemotherapy-associated venous thromboembolism in a prospective observational study. Cancer 2005; 104:2822-9. 32. Sorensen HT, Mellemkjaer L, Steffensen H, Olsen JH, Nielsen GL. The risk of a diagnosis of cancer after primary deep-venous thrombosis or pulmonary embolism. N Engl J Med 1998;338: 1169-73. 33. Baron JA, Gridley G, Weiderpass E, Nyren G, Linet M. Venous thromboembolism and cancer. Lancet 1998;351:1077-80. 34. Murchison JT, Wylie L, Stockton DL. Excess risk of cancer in patients with primary venous thromboembolism: a national, population-based cohort study. Br J Cancer 2004;91:92-5. 35. White RH, Chew HK, Zhou H, et al. Incidence of venous thromboembolism in the year before the diagnosis of cancer in 528,693 adults. Arch Intern Med 2005;165:1782-7. 36. Boccaccio C, Sabatino G, Medico E, et al. The MET oncogene drives a genetic programme linking cancer to haemostasis. Nature 2005;434:396-400. 37. van Aken BE, Reitsma PH, Rosendaal FR. Interleukin 8 and venous thrombosis: evidence for a role of inflammation in thrombosis. Br J Haematol 2002;116:173-7. 38. Tsai AW, Cushman M, Rosamond WD, et al. Coagulation factors, inflammation markers, and venous thromboembolism: the Longitudinal Investigation of Thromboembolism Etiology. Am J Med 2002;113:636-42. 39. Andreescu ACM, Cushman M, Rosendaal FR. D-dimer as a risk factor for deep vein thrombosis: the Leiden Thrombophilia Study. Thromb Haemost 2002;87:42-51. 40. Cushman M, Folsom AR, Wang L, Aleksic N, Rosamond WD, Tracy RP, Heckbert SR. Fibrin fragment D-dimer and the risk of future venous thrombosis. Blood. 2003;101:1243-8. 41. Prandoni P, Bilora F, Marchiori A, et al. An association between atherosclerosis and venous thrombosis. N Engl J Med 2003;348:1435-41. 42. Becattini C, Agnelli G, Prandoni P, et al. A prospective study on cardiovascular events after acute pulmonary embolism. Eur Heart J 2005;26:77-83. 43. Prandoni P, Ghirarduzzi A, Prins MH, et al. Venous thromboembolism and the risk of subsequent symptomatic atherosclerosis. J Thromb Haemost 2006;4:1891-96. 44. Bova C, Marchiori A, Noto A, et al. Incidence of arterial cardiovascular events in patients with idiopathic venous thromboembolism. A retrospective cohort study. Thromb Haemost 2006; 96:132-6. 45. Reich LM, Folsom AR, Key NS, et al. Prospective study of subclinical atherosclerosis as a risk factor for venous thromboembolism. J Thromb Haemost 2006;4:1909-13. 46. Van der Hagen PB, Folsom AR, Jenny NS, et al. Subclinical atherosclerosis and the risk of future venous thrombosis in the Cardiovascular Health Study. J Thromb Haemost 2006;4:19038. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 59 | Hodgkin’s Lymphoma The role of PET in staging and response assessment L. Specht Dept. of Oncology and Haematology The Finsen Centre Rigshospitalet Copenhagen University Hospital Copenhagen, Denmark Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:60-63 ositron emission tomography (PET) is a non-invasive, quantitative imaging technique which can visualize biochemical, physiological, and biological processes in vivo. It is, the most specific and sensitive molecular imaging techniqueused today. PET with 2-[18F]fluor-2deoxyglucose (FDG-PET) has proved a very valuable tool in the management of malignant disease including lymphomas. The first report of FDG-PET and lymphoma imaging was presented in 1987.1 This and other studies showed abnormal FDG uptake in most lymphomas with a correlation between the uptake rates and the malignancy grade and proliferative activity.2-8 Hodgkin lymphoma (HL) is generally FDG avid.9-16 Figure 1 shows a PET/CT scan of a patient with classic Hodgkin lymphoma. P FDG-PET in staging Physical examination and computed tomography (CT) combined with bone marrow and other biopsies when required have been the main point of reference in the staging of lymphomas.17 In the past, gallium scintigraphy was important for detecting lymphoma involvement. But FDG-PET has been shown to be significantly more sensitive, and gallium scintigraphy has now largely been abandoned.1,18–24 However, the standard procedures fail to identify a considerable number of sites, particularly extranodal ones. FDG-PET has been evaluated as a supplementary staging investigation in several studies. There are, however, methodological problems in these studies, the most important one being the lack of a valid reference test. Since it is not possible to obtain biopsies from all lymph node regions and organs of interest, a reference standard based on all available evidence from CT, FDG-PET, and all available clinical information including follow-up must be used instead. This method has serious limitations with regard to evaluating the diag| 60 | nostic accuracy of FDG-PET, but for the moment it is the best method available. The general conclusion so far of studies in (HL) and aggressive non-Hodgkin lymphoma (NHL) is that FDG-PET is more accurate for diagnosing both nodal and extranodal disease than CT, thus having a strong potential impact on the staging of (HL) and aggressive (NHL).10,12-14,16,20,25-42 In cases with bone marrow involvement, FDG-PET seems to be at least as sensitive as blind bone marrow biopsy.10,25,43 In general, more patients are upstaged than downstaged by FDG-PET. In the published series, FDG-PET changed the disease stage in 10-40% of patients. This led to changes in treatment strategy in about half of these patients.38 Whether the changes in treatment strategy caused by FDG-PET will eventually lead to improvement in treatment outcome is at present unknown. Clearly, the fact that FDG-PET upstages more patients than it downstages leads to stage migration and better treatment results both in patients with localized and in patients with advanced disease. Whether treatment modification based on FDG-PET will ultimately improve results is at present being tested in randomized trials. The use of FDG-PET in the staging and evaluation of (HL) is today considered part of the routine management in many institutions, and funding approval has been granted in most countries, including the United States. The recently proposed revised response criteria for malignant lymphoma including PET are designed also for HL. PET is therefore strongly recommended before treatment to better define the extent of disease.44 However, at the moment it is not compulsory because of limitations of cost and availability. FDG-PET in response evaluation Tumor response serves as an important substitute for other measures of clinical benefit such as progression-free and overall survival. Tumor response also serves as Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Cumulative progression-free survival 1.0 0.8 0.6 Early interim PET Negative Positive 0.4 0.2 p<0.0001 0.0 0 1 2 3 Time in years Figure 2. Progression-free survival of patients with Hodgkin lymphoma according to FDG-PET results after 2 cycles of chemotherapy. Reprinted with permission from Blood 2006;107:52-9. Figure 1. PET/CT scan of a patient with Hodgkin lymphoma CS IIIA with cervical, mediastinal and retroperitoneal involvement. an important guide in decisions to continue or change therapy. Response in lymphomas was previously assessed according to the International Workshop Criteria (IWC) based mainly on morphological criteria, with a reduction in tumor size on CT being the most important factor.45 However, after completion of therapy, CT will often reveal residual masses. By conventional methods it is very difficult to assess whether this represents viable lymphoma or fibrotic scar tissue. To perform a biopsy on all these lesions would be unpractical, and even if carried out would be too inaccurate because residual masses may contain a mixture of fibrosis and viable lymphoma cells and false negative results could be expected. This difficult situation led to the introduction in the IWF (and earlier Cotswold criteria for HL) of the problematic concept of CRu (complete remission/unconfirmed).45,46 Since changes in tissue function predate volume changes, it is possible to assess response using functional imaging. FDG-PET seems to be able, at least to a large extent, to distinguish between viable lymphoma and necrosis or fibrosis in residual masses after treatment of HL.28,30,47-60 Based on these findings, the International Harmonization Project has developed new recommendations for response criteria for malignant lymphomas, incorporating FDG-PET into the definitions of response in FDG-avid lymphomas.44 However, it is clear that a negative FDGPET scan after therapy does not exclude the presence of microscopic disease.53 For the moment, there is little clinical data to support the new recommendations for response criteria, and long-term follow-up of lymphoma patients evaluated by these criteria is awaited with great interest. Early studies in breast and colorectal cancer showed that glucose metabolism in responding tumors already changed markedly within the first weeks of therapy.61-63 Several studies in HL showed that an early FDG-PET scan, after 1-3 cycles of chemotherapy, is a strong predictor of treatment failure.64-68 Figure 2 shows progression-free survival curves according to FDG-PET after 2 cycles of chemotherapy in patients with HL in all stages. In advanced disease we have shown that the result of an early interim FDG-PET scan makes the International Prognostic Score insignificant. It is not yet clear if interventions based on the result of an early interim FDG-PET scan are called for. Randomized trials are now being set up to test if treatment modification based on the result of an Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 61 | 12th Congress of the European Hematology Association early interim PET scan, such as treatment reduction in PET negative patients and treatment intensification in PET positive patients, can improve outcome with respect to improved progression-free survival in patients with a poor prognosis and equivalent progression-free survival with less treatment (and, hence, a lower risk of long-term complications) in patients with a good prognosis. 20. 21. 22. 23. References 1. Paul R. Comparison of fluorine-18-2-fluorodeoxyglucose and gallium-67 citrate imaging for detection of lymphoma. J Nucl Med 1987;28:288-92. 2. Hutchings M, Loft A, Hansen M, Ralfkiaer E, Specht L. Different histopathological subtypes of Hodgkin lymphoma show significantly different levels of FDG uptake. Hematol Oncol 2006;24:146-50. 3. Lapela M, Leskinen S, Minn HR, Lindholm P, Klemi PJ, Soderstrom KO et al. Increased glucose metabolism in untreated non-Hodgkin's lymphoma: a study with positron emission tomography and fluorine-18-fluorodeoxyglucose. Blood 1995;86:3522-7. 4. Newman JS, Francis IR, Kaminski MS, Wahl RL. Imaging of lymphoma with PET with 2-[F-18]-fluoro-2-deoxy-D-glucose: correlation with CT. Radiology 1994;190:111-6. 5. Okada J, Yoshikawa K, Imazeki K, Minoshima S, Uno K, Itami J et al. The use of FDG-PET in the detection and management of malignant lymphoma: correlation of uptake with prognosis. J Nucl Med 1991;32:686-91. 6. Okada J, Yoshikawa K, Itami M, Imaseki K, Uno K, Itami J et al. Positron emission tomography using fluorine-18-fluorodeoxyglucose in malignant lymphoma: a comparison with proliferative activity. J Nucl Med 1992;33:325-9. 7. Rodriguez M, Rehn S, Ahlstrom H, Sundstrom C, Glimelius B. Predicting malignancy grade with PET in non-Hodgkin's lymphoma. J Nucl Med 1995;36:1790-6. 8. Schoder H, Noy A, Gonen M, Weng L, Green D, Erdi YE et al. Intensity of 18fluorodeoxyglucose uptake in positron emission tomography distinguishes between indolent and aggressive non-Hodgkin's lymphoma. J Clin Oncol 2005;23:4643-51. 9. Buchmann I, Moog F, Schirrmeister H, Reske SN. Positron emission tomography for detection and staging of malignant lymphoma. Recent Results Cancer Res 2000;156:78-89. 10. Buchmann I, Reinhardt M, Elsner K, Bunjes D, Altehoefer C, Finke J et al. 2-(fluorine-18)fluoro-2-deoxy-D-glucose positron emission tomography in the detection and staging of malignant lymphoma. A bicenter trial. Cancer 2001;91:889-99. 11. Burton C, Ell P, Linch D. The role of PET imaging in lymphoma. Br J Haematol 2004;126:772-84. 12. Hutchings M, Eigtved AI, Specht L. FDG-PET in the clinical management of Hodgkin lymphoma. Crit Rev Oncol Hematol 2004;52:19-32. 13. Hutchings M, Loft A, Hansen M, Pedersen LM, Berthelsen AK, Keiding S et al. Positron emission tomography with or without computed tomography in the primary staging of Hodgkin's lymphoma. Haematologica 2006;91:482-9. 14. Jerusalem G, Beguin Y, Fassotte MF, Najjar F, Paulus P, Rigo P et al. Whole-body positron emission tomography using 18Ffluorodeoxyglucose compared to standard procedures for staging patients with Hodgkin's disease. Haematologica 2001;86:266-73. 15. Jerusalem G, Hustinx R, Beguin Y, Fillet G. Positron emission tomography imaging for lymphoma. Curr Opin Oncol 2005;17:441-5. 16. Menzel C, Dobert N, Mitrou P, Mose S, Diehl M, Berner U et al. Positron emission tomography for the staging of Hodgkin's lymphoma--increasing the body of evidence in favor of the method. Acta Oncol 2002;41:430-6. 17. Specht L. Staging systems and staging investigations at presentation. In: Magrath I, editor. The Lymphoid Neoplasms. London: Hodder Arnold, 2006: in press. 18. Front D, Israel O. Present state and future role of gallium-67 scintigraphy in lymphoma. J Nucl Med 1996;37:530-2. 19. Kostakoglu L, Leonard JP, Kuji I, Coleman M, Vallabhajosula S, 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 25. 36. 37. 38. 39. 40. Goldsmith SJ. Comparison of fluorine-18 fluorodeoxyglucose positron emission tomography and Ga-67 scintigraphy in evaluation of lymphoma. Cancer 2002;94:879-88. Wirth A, Seymour JF, Hicks RJ, Ware R, Fisher R, Prince M et al. Fluorine-18 fluorodeoxyglucose positron emission tomography, gallium-67 scintigraphy, and conventional staging for Hodgkin's disease and non-Hodgkin's lymphoma. Am J Med 2002;112:262-8. Even-Sapir E, Israel O. Gallium-67 scintigraphy: a cornerstone in functional imaging of lymphoma. Eur J Nucl Med Mol Imaging 2003;30 Suppl 1:S65-S81. Friedberg JW, Fischman A, Neuberg D, Kim H, Takvorian T, Ng AK et al. FDG-PET is superior to gallium scintigraphy in staging and more sensitive in the follow-up of patients with de novo Hodgkin lymphoma: a blinded comparison. Leuk Lymphoma 2004;45:85-92. Kostakoglu L, Leonard JP, Coleman M, Goldsmith SJ. The Role of FDG-PET Imaging in the Management of Lymphoma. Clin Adv Hematol Oncol 2004;2:115-21. Van Den Bossche B., Lambert B, De Winter F, Kolindou A, Dierckx RA, Noens L et al. 18FDG PET versus high-dose 67Ga scintigraphy for restaging and treatment follow-up of lymphoma patients. Nucl Med Commun 2002;23:1079-83. Bangerter M, Moog F, Buchmann I, Kotzerke J, Griesshammer M, Hafner M et al. Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin's disease. Ann Oncol 1998;9:1117-22. Delbeke D, Martin WH, Morgan DS, Kinney MC, Feurer I, Kovalsky E et al. 2-deoxy-2-[F-18]fluoro-D-glucose imaging with positron emission tomography for initial staging of Hodgkin's disease and lymphoma. Mol Imaging Biol 2002;4:105-14. Hoh CK, Glaspy J, Rosen P, Dahlbom M, Lee SJ, Kunkel L et al. Whole-body FDG-PET imaging for staging of Hodgkin's disease and lymphoma. J Nucl Med 1997;38:343-8. Hueltenschmidt B, Sautter-Bihl ML, Lang O, Maul FD, Fischer J, Mergenthaler HG et al. Whole body positron emission tomography in the treatment of Hodgkin disease. Cancer 2001;91:302-10. Isasi CR, Lu P, Blaufox MD. A metaanalysis of 18F-2-deoxy-2fluoro-D-glucose positron emission tomography in the staging and restaging of patients with lymphoma. Cancer 2005;104:1066-74. Jerusalem G, Warland V, Najjar F, Paulus P, Fassotte MF, Fillet G et al. Whole-body 18F-FDG PET for the evaluation of patients with Hodgkin's disease and non-Hodgkin's lymphoma. Nucl Med Commun 1999;20:13-20. Moog F, Bangerter M, Diederichs CG, Guhlmann A, Kotzerke J, Merkle E et al. Lymphoma: role of whole-body 2-deoxy-2[F-18]fluoro-D-glucose (FDG) PET in nodal staging. Radiology 1997;203:795-800. Moog F, Bangerter M, Diederichs CG, Guhlmann A, Merkle E, Frickhofen N et al. Extranodal malignant lymphoma: detection with FDG PET versus CT. Radiology 1998;206:475-81. Moog F, Kotzerke J, Reske SN. FDG PET can replace bone scintigraphy in primary staging of malignant lymphoma. J Nucl Med 1999;40:1407-13. Munker R, Glass J, Griffeth LK, Sattar T, Zamani R, Heldmann M et al. Contribution of PET imaging to the initial staging and prognosis of patients with Hodgkin's disease. Ann Oncol 2004;15:1699-704. Partridge S, Timothy A, O'Doherty MJ, Hain SF, Rankin S, Mikhaeel G. 2-Fluorine-18-fluoro-2-deoxy-D glucose positron emission tomography in the pretreatment staging of Hodgkin's disease: influence on patient management in a single institution. Ann Oncol 2000;11:1273-9. Rini JN, Leonidas JC, Tomas MB, Palestro CJ. 18F-FDG PET versus CT for evaluating the spleen during initial staging of lymphoma. J Nucl Med 2003;44:1072-4. Sasaki M, Kuwabara Y, Koga H, Nakagawa M, Chen T, Kaneko K et al. Clinical impact of whole body FDG-PET on the staging and therapeutic decision making for malignant lymphoma. Ann Nucl Med 2002;16:337-45. Schiepers C, Filmont JE, Czernin J. PET for staging of Hodgkin's disease and non-Hodgkin's lymphoma. Eur J Nucl Med Mol Imaging 2003;30 Suppl 1:S82-S88. Schoder H, Meta J, Yap C, Ariannejad M, Rao J, Phelps ME et al. Effect of whole-body (18)F-FDG PET imaging on clinical staging and management of patients with malignant lymphoma. J Nucl Med 2001;42:1139-43. Shah N, Hoskin P, McMillan A, Gibson P, Lowe J, wong WL. The impact of FDG positron emission tomography imaging on the management of lymphomas. Br J Radiol 2000;73:482-7. | 62 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 41. Stumpe KD, Urbinelli M, Steinert HC, Glanzmann C, Buck A, von Schulthess GK. Whole-body positron emission tomography using fluorodeoxyglucose for staging of lymphoma: effectiveness and comparison with computed tomography. Eur J Nucl Med 1998;25:721-8. 42. Weihrauch MR, Re D, Bischoff S, Dietlein M, Scheidhauer K, Krug B et al. Whole-body positron emission tomography using 18F-fluorodeoxyglucose for initial staging of patients with Hodgkin's disease. Ann Hematol 2002;81:20-5. 43. Carr R, Barrington SF, Madan B, O'Doherty MJ, Saunders CA, van der Walt J. et al. Detection of lymphoma in bone marrow by whole-body positron emission tomography. Blood 1998;91:3340-6. 44. Cheson BD, Pfistner B, Juweid ME, Gascoyne RD, Specht L, Horning SJ et al. Revised Response Criteria for Malignant Lymphoma. J Clin Oncol 2007;25:579-86. 45. Cheson BD, Horning SJ, Coiffier B, Shipp MA, Fisher RI, Connors JM et al. Report of an international workshop to standardize response criteria for non-Hodgkin's lymphomas. NCI Sponsored International Working Group. J Clin Oncol 1999;17:1244. 46. Lister TA, Crowther D, Sutcliffe SB, Glatstein E, Canellos GP, Young RC et al. Report of a committee convened to discuss the evaluation and staging of patients with Hodgkin's disease: Cotswolds meeting. J Clin Oncol 1989;7:1630-6. 47. Bangerter M, Kotzerke J, Griesshammer M, Elsner K, Reske SN, Bergmann L. Positron emission tomography with 18-fluorodeoxyglucose in the staging and follow-up of lymphoma in the chest. Acta Oncol 1999;38:799-804. 48. de Wit M, Bohuslavizki KH, Buchert R, Bumann D, Clausen M, Hossfeld DK. 18FDG-PET following treatment as valid predictor for disease-free survival in Hodgkin's lymphoma. Ann Oncol 2001;12:29-37. 49. Dittmann H, Sokler M, Kollmannsberger C, Dohmen BM, Baumann C, Kopp A et al. Comparison of 18FDG-PET with CT scans in the evaluation of patients with residual and recurrent Hodgkin's lymphoma. Oncol Rep 2001;8:1393-9. 50. Guay C, Lepine M, Verreault J, Benard F. Prognostic value of PET using 18F-FDG in Hodgkin's disease for post-treatment evaluation. J Nucl Med 2003;44:1225-31. 51. Jerusalem G, Beguin Y, Fassotte MF, Najjar F, Paulus P, Rigo P et al. Whole-body positron emission tomography using 18Ffluorodeoxyglucose for post-treatment evaluation in Hodgkin's disease and non-Hodgkin's lymphoma has higher diagnostic and prognostic value than classical computed tomography scan imaging. Blood 1999;94:429-33. 52. Lang O, Bihl H, Hultenschmidt B, Sautter-Bihl ML. Clinical relevance of positron emission tomography (PET) in treatment control and relapse of Hodgkin's disease. Strahlenther Onkol 2001;177:138-44. 53. Lavely WC, Delbeke D, Greer JP, Morgan DS, Byrne DW, Price RR et al. FDG PET in the follow-up management of patients with newly diagnosed Hodgkin and non-Hodgkin lymphoma after first-line chemotherapy. Int J Radiat Oncol Biol Phys 2003;57:307-15. 54. Naumann R, Vaic A, Beuthien-Baumann B, Bredow J, Kropp J, Kittner T et al. Prognostic value of positron emission tomography in the evaluation of post-treatment residual mass in patients with Hodgkin's disease and non-Hodgkin's lymphoma. Br J Haematol 2001;115:793-800. 55. Panizo C, Perez-Salazar M, Bendandi M, Rodriguez-Calvillo M, Boan JF, Garcia-Velloso MJ et al. Positron emission tomography using 18F-fluorodeoxyglucose for the evaluation of 56. 58. 59. 60. 61. 62. 63. 54. 65. 66. 67. 68. residual Hodgkin's disease mediastinal masses. Leuk Lymphoma 2004;45:1829-33. Reinhardt MJ, Herkel C, Altehoefer C, Finke J, Moser E. Computed tomography and 18F-FDG positron emission tomography for therapy control of Hodgkin's and nonHodgkin's lymphoma patients: when do we really need FDGPET? Ann Oncol 2005;16:1524-9. (57) Rigacci L, Castagnoli A, Dini C, Carpaneto A, Matteini M, Alterini R et al. 18FDG-positron emission tomography in post treatment evaluation of residual mass in Hodgkin's lymphoma: long-term results. Oncol Rep 2005;14:1209-14. Spaepen K, Stroobants S, Dupont P, Thomas J, Vandenberghe P, Balzarini J et al. Can positron emission tomography with [(18)F]-fluorodeoxyglucose after first-line treatment distinguish Hodgkin's disease patients who need additional therapy from others in whom additional therapy would mean avoidable toxicity? Br J Haematol 2001;115:272-8. Weihrauch MR, Re D, Scheidhauer K, Ansen S, Dietlein M, Bischoff S et al. Thoracic positron emission tomography using 18F-fluorodeoxyglucose for the evaluation of residual mediastinal Hodgkin disease. Blood 2001;98:2930-4. Zijlstra JM, Lindauer-van der Werf G, Hoekstra OS, Hooft L, Riphagen II, Huijgens PC. 18F-fluoro-deoxyglucose positron emission tomography for post-treatment evaluation of malignant lymphoma: a systematic review. Haematologica 2006;91:522-9. Findlay M, Young H, Cunningham D, Iveson A, Cronin B, Hickish T et al. Noninvasive monitoring of tumor metabolism using fluorodeoxyglucose and positron emission tomography in colorectal cancer liver metastases: correlation with tumor response to fluorouracil. J Clin Oncol 1996;14:700-8. Jansson T, Westlin JE, Ahlstrom H, Lilja A, Langstrom B, Bergh J. Positron emission tomography studies in patients with locally advanced and/or metastatic breast cancer: a method for early therapy evaluation? J Clin Oncol 1995;13:1470-7. Wahl RL, Zasadny K, Helvie M, Hutchins GD, Weber B, Cody R. Metabolic monitoring of breast cancer chemohormonotherapy using positron emission tomography: initial evaluation. J Clin Oncol 1993;11:2101-11. Gallamini A, Rigacci L, Merli F, Nassi L, Bosi A, Capodanno I et al. The predictive value of positron emission tomography scanning performed after two courses of standard therapy on treatment outcome in advanced stage Hodgkin's disease. Haematologica 2006;91:475-81. Hutchings M, Mikhaeel NG, Fields PA, Nunan T, Timothy AR. Prognostic value of interim FDG-PET after two or three cycles of chemotherapy in Hodgkin lymphoma. Ann Oncol 2005;16:1160-8. Hutchings M, Loft A, Hansen M, Pedersen LM, Buhl T, Jurlander J et al. FDG-PET after two cycles of chemotherapy predicts treatment failure and progression-free survival in Hodgkin lymphoma. Blood 2006;107:52-9. Kostakoglu L, Coleman M, Leonard JP, Kuji I, Zoe H, Goldsmith SJ. PET predicts prognosis after 1 cycle of chemotherapy in aggressive lymphoma and Hodgkin's disease. J Nucl Med 2002;43:1018-27. Zinzani PL, Tani M, Fanti S, Alinari L, Musuraca G, Marchi E et al. Early positron emission tomography (PET) restaging: a predictive final response in Hodgkin's disease patients. Ann Oncol 2006;17:1296-300. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 63 | Hodgkin’s Lymphoma Tailoring the treatment for early-stage Hodgkin’s lymphoma M. André1 O. Reman2 1 Centre Hospitalier Notre Dame & Reine Fabiola, Charleroi, Belgium; 2 CHU de Caen, Caen, Belgium Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:64-69 he optimal treatment strategy for early-stage Hodgkin lymphoma is still the subject of intense debate.1,2 The key issue is: can we further decrease treatment without compromising the excellent results and, while reducing treatment, decrease devastating late toxicities? The purpose of this review is to summarize the current achievement of chemo-radiotherapy, chemotherapy alone and ways to better define the treatment of early-stage Hodgkin lymphoma patients. T Tailoring to histology: the nodular lymphocyte-predominant Hodgkin lymphoma This lymphoma is pathologically and clinically distinct from classic Hodgkin lymphoma (cHL). Nodular lymphocytepredominant Hodgkin lymphoma (NLPHL) is characterized by atypical lymphocytic and histiocytic (L&H) or popcorn cells. L&H cells usually express the B-cell marker CD20 and lack expression of CD15 and CD30,3 the characteristic markers for cHL. Compared to cHL, more patients will present with early or intermediate stage, are male and with less B symptoms.4 The disease is commonly limited to one site (such as groin, neck, axilla) and involvement of the mediastinum is infrequent at the moment. NLPHL are not generally included in cHL trials and treatment recommendations differ from those of cHL. NLPHL is infrequent, there are no randomized trials and the choice of treatment is difficult. The German Hodgkin Study Group (GHSG) recently reviewed patients included in several successive trials and compared the different treatment approaches, such as extended field (EFRT), involved field (IFRT) radiation and combined modality treatment (CMT) for LPHL stage IA patients. In terms of remission, induction IF radiotherapy for stage IA LPHL patients is as effective as EFRT or CMT treatment. However, a longer follow-up is needed before final conclusion can be made about optimal therapy.5 Other treatment options include chemo| 64 | therapy and use of rituximab since the L&H cells express CD20.6 Recently, some have suggested that patients in complete remission after biopsy could benefit from observation with no further therapy.7 The GELA/EORTC, GHSG and NCCN recommend IFRT for NLPHL in early favourable stages. However, there is no randomized trial to support this recommendation. The diversity of treatment options available for localized NLPHL, the good survival and risk of late toxicities emphasize the need for an intergroup randomized trial. Prognostic factors to tailor the treatment of early stage cHL The Ann Arbour staging classification with Costwold modifications8 is shown in Table 1 and allows the distinction between advanced and early stages. For patients with advanced stage, The International Prognostic Index defined prognostic factors that are nowadays used in all randomized trials.9 Recently, IPS has also been applied to patients with earlystage disease.10,11 However in these times of chemo-radiotherapy, early stage patients are generally separated into two categories (favorable and unfavorable) to define treatment. But slightly different criteria are used by different groups (Table 2). Basically, more courses or more intensive chemotherapy is recommended for unfavorable patients. Most trials using chemotherapy alone were limited to favourable patients. The question whether E lesions are prognostically significant remains controversial since there is a wide disagreement about E lesion definition. Biological prognostic factors In addition to commonly used prognostic factors, some investigators have studied biologic markers that might provide additional prognostic information to these clinical models. Several candidate molecules, including bcl-2 P53 and human germinal centre-associated lymphoma pro- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 1. Modified Ann Arbor staging system for Hodgkin lymphoma. Stage Involvement I Single lymph node region (I) or one extralymphatic side (IE) Two or more lymph node regions, same side of the diaphragm (II) and local extralymphatic extension plus one or more lymph node regions same side of the diaphragm (IIE). Lymph node region on both sides of the diaphragm (III) which may be accompanied by local extralymphatic extension (IIIE) Diffuse involvement of one or more extralymphatic organs or sites. II III IV Symptoms A No B symptoms B Presence of at least one of the following: 1. Unexplained weight loss >10% baseline during 6 months prior to staging 2. Recurrent unexplained fever >38° 3. Recurrent night sweats tein, have recently been proposed.12,13 The independent predictive power of these markers is controversial and none has gained wide acceptance in clinical trials. Combined modality treatment Between 1950 and 1980, treatment strategy maximized the use of extensive radiotherapy (RT) because historically it was considered the only curative method and less toxic than MOPP. The lessons from this period should not be limited to the awareness of the late toxic effects but the high effectiveness of RT as a single agent should also be recognised. Since then several randomized trials have shown better results with CMT as compared to RT alone14, 15,16 (Table 3). In the GHSG HD7 study,15 the patients receiving CMT had a better FFTF when compared to RT alone. In the GELA/EORTC H7F and H8F,16,17 similarly improved results for RFS were obtained with CMT despite the reduction of the field of radiotherapy to the site of originally involved nodes (involved-field radiotherapy). It is now clear that chemotherapy plus radiotherapy not only improves relapse-free survival, but can also replace Table 2. Early stage cHL risk factors in treatment groups. RF Treatment groups Early stage favorable Early stage unfavourable Advanced stage GELA/EORTC GHSG NCCN 1. Large MM 2. Age ≥ 50 3. B symptoms or ESR>50 4. ≥4 involved sites 1. Large MM 2. Extranodal disease 3. B symptoms or ESR≥50 4. ≥3 involved sites 1. Large MM/any >10 cm 2. B symptoms or ESR≥50 3. ≥4 involved sites CS I-II with no RF CS I-II with any RF CS III-IV CS I-II with no RF CS I, CS IIA with any RF, CS IIB withC/D but without A/B CS IIB with A/B, CS III-IV No RF Any RF CS III-IV * If B symptoms, ESR should be >30. Abbreviation : GELA: Groupe d’Etudes des Lymphomes de l’Adulte; EORTC: European Organization for Reasearch and Treatment of Cancer; GHSG: German Hodgkin Lymphoma Study Group; NCCN: National Comprehensive Cancer Network; RF: risk factors; MM: mediastinal mass; ESR: erythrocyte sedimentation rate; CS: clinical stage. Table 3. Early stage cHL risk factors in treatment groups. Trial Treatment RFS or FFTF OS (%) OS (years) GHSG HD715 (617 pts) EF 2 ABVD + EF 75 91 p<.001 94 94 P:ns 5 EORTC H7F16 (333 pts) STLI 6 EBVP + IF 78 88 p=0.0113 92 p:ns 10 EORTC/GELA H8F18 (543 pts) STLI MOPP/ABV 80 99 SWOG #913314 (326 pts) STLI 3 AV + STLI 81 94 p<.001 4 96 98 p=ns 3 RT: radiotherapy; CMT: combined modality therapy; GELA: Groupe d’Etudes des Lymphomes de l’Adulte; EORTC: European Organization for Reasearch and Treatment of Cancer; GHSG: German Hodgkin Lymphoma Study Group; RFS: relapse free survival; FFTF: freedom from treatment failure; OS: overall survival; ns:not significant; EF: extended field; IF: involved field; STLI: sub-total lymphoid irradiation. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 65 | 12th Congress of the European Hematology Association Table 4. Randomized trials comparing CMT with chemotherapy alone. Author Longo29 Biti30 Pavlovsky31 Strauss32 Laskar33 Nachman34 Eghbali25 Meyer35 Design MOPP vs MOPP + EF MOPP vs MOPP + EF CVPP vs CVPP + IF ABVD vs ABVD +EF or IF ABVD vs ABVD + IF COP-ABV vs COP-ABV + IF EBVP + IF vs EBVP STNI +/- ABVD vs ABVD N 106 99 277 152 99 362 578 399 Results No difference No difference No difference in the favourable group No difference No difference No difference EFS p<.001 DFS p=0.006 EF: extended field, IF: involved field, STNI: sub-total nodal irradiation radiotherapy as adjuvant treatment for sub-clinical disease. Several trials have demonstrated that reducing the fields of radiotherapy from subtotal lymphoid irradiation or EFRT to IFRT have produced similar results with what seens to be less toxic effects (Table 4).18,19,20 In a randomized trial in Milan19 it was demonstrated that ABVD followed by extended field or involved field RT produced similar results. The HD8 trial of the GHSG gave similar results, less acute toxicity (significant improvement for nausea, leukopenia, thrombopenia, pharyngeal and gastro-intestinal effects) and also a trend toward fewer secondary cancers (24 in the EF arm (4.5%) and 15 in the IF arm (2.8%)). A subset analysis of this trial also suggested that older patients experienced poorer outcome in the extended field arm (OS, 59% vs 81%, p=0.008).20 The definition of IFRT remains unsettled. A recent publication by Girinsky et al.21 suggested that fields that target only the involved lymph nodes, as defined by using modern imaging technologies, can be used to further reduce the field size of radiation from the current IFRT to involved-node radiation therapy. The authors based their suggestion on the fact that most of recurrences occur in the original nodal sites. This was confirmed by Shahidi et al.22 from Royal Marsden, who reported in a retrospective failure analysis of 61 patients with stage I and II Hodgkin's lymphoma treated without radiation that 83% of the recurrences developed in original sites of disease (45% as the only site). In addition to smaller radiation fields, the radiation dose used in modernday therapy has also been reduced from 45-54 Gy to 30 Gy or even lower in the modern randomized trials. Koontz et al.23 retrospectively compared CMT consisting of chemotherapy and low-dose IFRT (mean dose 25.5 Gy) to definitive radiation with a mean dose of 37.9 Gy. The authors found the CMT to be equally effective in curing patients with earlystage Hodgkin's lymphoma (20-year overall survival, 83% for CMT vs 70% for radiation alone) with fewer cardiac complications and second malignancies. The GHLSG HD10 again confirmed the safety of lowering the radiation dose. In this trial, 1,370 patients with favourable early-stage Hodgkin's lymphoma were randomly assigned to IFRT of 30 Gy or 20 Gy, and at their 4-year interim analysis, the freedom from treatment failure was similar.24 The EORTC/GELA H9F trial also compared IFRT 36Gy vs 20 Gy and showed no significant difference with a follow-up of 51 months.25 However, since the final analyses of these two trials (HD10 and H9F) have not yet been carried out, the recommended dose remains 30 Gy. The temptation to omit radiotherapy With more than 90% of patients cured by the current treatment, survival is more influenced by late toxicity, and more precisely, by second cancers. The currently used chemotherapy, ABVD, results in very low toxicity with no demonstrated increase for secondary leukaemia or solid tumours. It has been known for more than 20 years that the use of radiation therapy is associated with significant rates of second cancers presenting 10 or more years after treatment completion. We now know that thoracic radiation in women treated under the age of 30 years results in a very high rate of breast cancer of approximatly 30% at 30 years following treatment. This risk is dose dependent and is much lower in women who received alkylating agent chemotherapy with no hormone replacement therapy.26 We also know that after thoracic radiation for Hodgkin lymphoma heavy smokers have a 20 times higher risk of lung cancers while light or non-smokers have a 7 times higher risk.27 Higher dose and volume of radiation increases these risks. The use of smaller and better defined radiation volumes allowed the utilization of more conformal radiation therapy based on improved imaging, and when indicated, tools such as intensity modulated RT. However, so far studies have not demonstrated a decrease in late secondary cancers for long-term survivors of cHL.28 In a recently published meta-analysis, IF-RT versus EF-RT (19 trials, 3,221 patients), there was no significant difference in secondary malignancy risk (p=0.28) although more breast cancers occurred with EF-RT (p=0.04 | 66 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 and OR=3.25).40 Given this increased risk for secondary toxicities, several groups have proposed to omit RT and give chemotherapy, mostly ABVD, alone. Several studies have published results showing similar outcomes with chemotherapy alone compared to CMT (Table 4).29-34 Four of these trials used chemotherapy that has been shown to be inferior to the current standard ABVD and cannot therefore been used to give current guidelines. Furthermore some of these four trials were too small to detect important differences. The CCG trial based on a paediatric population only34 showed no difference in an intent-to-treat analysis. An analysis as-treated was also performed and showed a 3-year EFS of 93% for those who received RT and 85% for observation (p=0.024).Two trials31,34 were subset analysis. The two largest trials had the power to detect significant differences. In the EORTC/GELA H9F,25 after 6 cycles of EBVP (epirubicin, bleomycin, vinblastine, prednisone), CR/CRu patients were randomized between 36 Gy IF-RT, 20 Gy IF-RT and no RT. From September 1998 to May 2004, 783 patients were enrolled and 578 randomized after EBVP. Inclusion of patients in the no-RT arm was stopped early because stopping rules were met (that is > 20% of events). The 4-year EFS were 88%, 85% and 69% for 36 Gy, 20 Gy and no RT respectively. Median follow-up is 4.2 years. In the National Cancer Institute of Canada trial,35 in comparison with ABVD alone, 5-year freedom from disease progression is superior in patients allocated to radiation therapy (p=0.006; 93% v 87%). No differences in event-free survival (p=0.06; 88% v 86%) or overall survival (p=0.4; 94% v 96%) were observed. In a subset analysis comparing patients stratified into the unfavorable cohort, freedom from disease progression was superior in patients allocated to combined-modality treatment (p=0.004; 95% v 88%): No difference in overall survival was detected (p=0.3; 92% v 95%). Of the 15 deaths observed, nine were attributed to causes other than Hodgkin's lymphoma or acute treatment-related toxicity. In patients with limited-stage Hodgkin's lymphoma, no difference in overall survival was observed between patients randomly assigned to receive treatment that includes radiation therapy or ABVD alone. Although 5-year freedom from disease progression was superior in patients receiving radiation therapy, this advantage is offset by deaths due to causes other than progressive Hodgkin's lymphoma or acute treatmentrelated toxicity. Current trials The ongoing GHSG HD13 in favourable early stage randomly assigns patients to four arms: 2 cycles of ABVD, ABV, AVD or AV followed by IFRT 30 Gy. Enrolment is ongoing but the AVD and AV arms were closed due to an excessive number of Hodgkin events. In the unfavourable group of GHSG HD11 HD11, patients are randomized between 4 ABVD vs 4 BEACOPP baseline followed by IFRT 20 vs 30 Gy. Enrolment is completed with no difference between the arms reported so far. In North America, earlystage unfavourable patients are randomized to receive either 6 ABVD and IFRT vs Stanford V followed by IFRT to sites ≥ 5 cm. Using PET to tailor the treatment? After completion or during treatment, restaging by physical examination and CT-scan is not useful to predic ultimate outcome. Using F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan in the evaluation of treatment response in HL, the negative predictive value is high (81-100%) showing the ability of FDG-PET to identify patients with excellent prognosis. The positive predictive value is more variable (25-100%). When results of FDG-PET are interpreted in combination with clinical history and CT-scan, the positive predictive value increases to >85%, residual activity being strongly suggestive of active Hodgkin residue36) Treatment-induced tumour cell death or growth arrest reduce the FDG uptake in non-Hodgkin’s lymphoma as early as 7 days after start of therapy. There is less data for cHL. Three studies merit special attention with regard to the predictive value of early response evaluation: 1. In a retrospective study by Hutchings et al. FDGPET was performed after 2-3 cycles of chemotherapy in 85 cHL patients. The interim PET scans were negative in 63 patients, showed minimal residual uptake in 9 patients and were positive in 13 patients. The 5year progression free survival was 92%, 88% and 42% respectively.37 2. These findings were confirmed in a prospective study in 77 cHL patients. PET scans were performed after 2 cycles of chemotherapy. Two out of the 61 PET-negative patients experienced treatment failure, in comparison with 10 out of 16 PET-positive patients. With a median follow-up of 20 months, highly significant associations were reported between early interim FDG-PET and progression free survival (p<0.0001) and overall survival (p<0.01).38 3. In the Gallamini study,39 the end-point was the predictive value of PET-2 on 2-year progression-free survival and 2-year failure-free survival. The PET-2 was positive in 20 out of 108 patients. Seventeen progressed during therapy, one relapsed and two remained in CR. By contrast, 85/88 (97%) patients with a negative PET-2 remained in CR. Thus, the positive predictive value of a PET-2 was 90% and the negative predictive value was 97%. The sensitivity, specificity and overall accuracy of PET-2 were 86%, 98% and 95% respectively. The 2-year probability of Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 67 | 12th Congress of the European Hematology Association 2 cycles ABVD RANDOMIZATION STRATUM F FAVORABLE FDGPET Hodgkin’s lymphoma stage I/II any outcome of PET scan negative 2 cycles ABVD untreated, age 15 to 70 2 cycles ABVD FDGPET RANDOMIZATION STRATUM U UNFAVORABLE any outcome of PET scan negative 2 cycles ABVD 2 cycles escalated BEACOPP IN-RT 30 Gy (+ boost 6 Gy residual) 2 cycles ABVD IN-RT 30 Gy (+ boost 6 Gy residual) 4 cycles ABVD FDGPET positive ABVD: doxorubicin (adriamycin), bleomycin, vinblastine, dacarbazine Esc. BEACOPP: bleomycin, etoposide, doxorubicin (adriamycine), cyclophosphamide, vincristine, procarbazine, prednisone INRT - Involved-Node Radiation Therapy. 2 cycles ABVD FDGPET positive No LP nodular! 1 cycle ABVD IN-RT 30 Gy (+ boost 6 Gy residual) Second Registration 2 cycles escalated BEACOPP IN-RT 30 Gy (+ boost 6 Gy residual) Figure 1. The H10 GELA/EORTC trial. failure-free survival for PET-2 negative and for PET-2 positive patients was 96% and 6% respectively (log rank test = 116.7, p<0.01). From these data it can be concluded that early assessment of response to chemotherapy with FDGPET is an accurate predictor of progression free survival and overall survival in Hodgkin lymphoma. Therefore, in the currently ongoing EORTC/GELA H10 trial, the early response to treatment analyzed by FDG-PET scan, is used as a guidance to early treatment adaptation. Patients with a negative FDG-PET after 2 cycles of ABVD constitute the good-risk group for whom treatment burden can be reduced (Figure 1). Conclusions The current recommendations for the treatment of early stage cHL is CMT, including a short course of ABVD followed by IFRT. Given the excellent results produced by this approach and the incidence of secondary cancers, further trials will focus on a further reduction of treatment. This will be achieved by attempting to tailor treatment to initial response. References 1. Yahalom J. Don't throw out the baby with the bathwater: on optimizing cure and reducing toxicity in Hodgkin's lymphoma. J Clin Oncol 2006; 24: 544-8. 2. Longo DL. Radiation therapy in Hodgkin disease: Why risk a Pyrrhic victory? J Natl Cancer Inst 2005;97:1394-5. 3. Anagnostopoulos I, Hansmann ML, Fransilla K et al. European Task Force on Lymphoma project on lymphocyte predominance Hodgkin disease: histologic and immunhistologic analysis of submitted cases reveals 2 types of Hodgkin disease with a nodular growth pattern and abundant lymphocytes. Blood 2000;96:1889-99. 4. Nogová L, Reineke T, Eich HT et al. Lymphocyte-predominant and classical Hodgkin's lymphoma--comparison of outcomes. Eur J Haematol Suppl 2005;:106-10. 5. Nogová L, Reineke T, Eich HT et al. Extended field radiotherapy, combined modality treatment or involved field radiotherapy for patients with stage IA lymphocyte-predominant Hodgkin's lymphoma: a retrospective analysis from the German Hodgkin Study Group (GHSG). Ann Oncol 2005;16: 1683-7. 6. Ekstrand BC, Lucas JB, Horwitz SM et al. Rituximab in lymphocyte-predominant Hodgkin disease: results of a phase 2 trial. Blood 2003;10:4285-42. 7. Pellegrino B, Terrier-Lacombe MJ, Oberlin O et al. Lymphocyte-predominant Hodgkin's lymphoma in children: therapeutic abstention after initial lymph node resection--a Study of the French Society of Pediatric Oncology. J Clin Oncol 2003; 21: 2948-52. 8. Lister TA, Crowther D, Sutcliffe SB et al. Report of a committee convened to discuss the evaluation and staging of patients with Hodgkin’s disease: costwolds meeting. J Clin Oncol 1989;7:1630-6. 9. Hasenclever D, Diehl V. A prognostic score for advanced | 68 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. Hodgkin's disease. International Prognostic Factors Project on Advanced Hodgkin's Disease.N Engl J Med. 1998;339:1506-14. Franklin J, Paulus U, Lieberz D, et al. Is the International Prognostic Score for advanced stage Hodgkin's disease applicable to early stage patients? German Hodgkin Lymphoma Study Group. Ann Oncol. 2000;1 1:617-623. Gisselbrecht C, Mounier N, Andre M et al. How to define intermediate stage in Hodgkin's lymphoma? Eur J Haematol Suppl 2005 Jul;(66):111-4. Natkunam Y, Hsi ED, Aoun P, et al. Expression of the human germinal centre–associated lymphoma (HGAL) protein identifies a subset of classic Hodgkin lymphoma of germinal centre derivation and improved survival. Blood 2007 109: 298-305. Sup SJ, Alemany CA, Pohlman B, et al. Expression of bcl-2 in classical Hodgkin's lymphoma: an independent predictor of poor outcome. J Clin Oncol 2005;23:3773-9. Press OW, LeBlanc M, Lichter AS et al. Phase III randomized intergroup trial of subtotal lymphoid irradiation versus doxorubicin, vinblastine, and subtotal lymphoid irradiation for stage IA to IIA Hodgkin's disease. J Clin Oncol. 2001;19:423844. Sieber M, Franklin J, Tesch H et al. Two cycles of ABVD plus extended field radiotherapy is superior to radiotherapy alone in early stage Hodgkin’s disease: results of the German Hodgkin’s Study Group Trial HD7. Blood 100:A341, 2002. Noordijk EM, Carde P, Dupouy N et al. Combined-modality therapy for clinical stage I or II Hodgkin's lymphoma: longterm results of the European Organisation for Research and Treatment of Cancer H7 randomized controlled trials. J Clin Oncol 2006;24:3128-35. Engert A, Schiller P, Josting A et al. Involved-field radiotherapy is equally effective and less toxic compared with extendedfield radiotherapy after four cycles of chemotherapy in patients with early-stage unfavorable Hodgkin's lymphoma: results of the HD8 trial of the German Hodgkin's Lymphoma Study Group. J Clin Oncol 2003;21:3601-8. Hagenbeek A, Eghbali H, Ferme C et al. Three cycles of MOPP/ABV hybrid and involved-field radiotherapy irradiation is more effective than subtotal nodal irradiation in favourable supradiaphragmatic clinical satge I-II Hodgkin’s disease: preliminary results of the EORTC-GELA H8-F randomized trial in 543 patients. Blood 2000;96, abstract 575. Bonadonna G, Bonfante V, Viviani S et al. ABVD plus subtotal nodal versus involved-field radiotherapy in early-stage Hodgkin's disease: long-term results. J Clin Oncol. 2004;22:2835-41. Klimm B, Eicht HT, Haverkamp H et al. Poorer outcome of elderly patients treated with extended-field radiotherapy compared with involved-field radiotherapy after chemotherapy for Hodgkin's lymphoma: an analysis from the German Hodgkin Study Group. Ann Oncol 2006;2006 Oct 27;[Epub ahead of print]. Girinski T, van der Maazen R et al. Involved-node radiotherapy (INRT) in patients with early Hodgkin lymphoma: concepts and guidelines. Radiother Oncol 2006 Jun;79:270-7. Epub 2006 Jun 22. Shahidi M, Kamangari N, Ashley S, et al. Site of relapse after chemotherapy alone for stage I and II Hodgkin's disease. Radiother Oncol 2006;78:1-5. Koontz BF, Kirkpatrick JP, Clough RW, et al. Combined-modality therapy versus radiotherapy alone for treatment of earlystage Hodgkin's disease: Cure balanced against complications. J Clin Oncol 2006;24:605-11. Diehl V, Brillant C, Engert A, et al. Investigating reduction of combined modality treatment intensity in early stage Hodgkin's lymphoma: Interim analysis of a randomized trial of the German Hodgkin's Study Group (GHSG). J Clin Oncol 2005. 23:561s, abstract 6506. H Eghbali, P Brice, GY Creemers et al. Comparison of Three Radiation Dose Levels after EBVP Regimen in Favorable 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. Supradiaphragmatic Clinical Stages (CS) I-II Hodgkin’s Lymphoma (HL): Preliminary Results of the EORTC-GELA H9-F Trial. Blood 2005, A106, 814. Travis LB, Hill D, Dores GM, et al. Cumulative absolute breast cancer risk for young women treated for Hodgkin lymphoma. J Natl Cancer Inst 2005;97:1428-37. Travis LB, Gospodarowicz M, Curtis RE, et al. Lung cancer following chemotherapy and radiotherapy for Hodgkin’s disease. J Natl Cancer Inst 2002;94:182-92. Dores, Catherine Metayer, Rochelle E. Curtis et al. Second malignant neoplasms among long-term survivors of Hodgkin's disease: a population-based evaluation over 25 years. J Clin Oncol 2002:20;3484. Longo DL, Glatstein E, Duffey PL, et al. Radiation therapy versus combination chemotherapy in the treatment of early-stage Hodgkin’s disease: seven-year results of a prospective randomized trial. J Clin Oncol 1991;9:906-17. Biti GP, Cimino G, Cartoni C, et al. Extended-field radio-therapy is superior to MOPP chemotherapy for the treatment of pathologic stage I–IIA Hodgkin’s disease: eight-year update of an Italian prospective randomized study. J Clin Oncol 1992; 10:378-82. Pavlovsky S, Maschio M, Santarelli MT, et al. Randomized trial of chemotherapy versus chemotherapy plus radiotherapy for stage I–II Hodgkin’s disease. J Natl Cancer Inst 1988;80: 1466-73. Straus DJ, Portlock CS, Qin J, et al. Results of a prospective randomized clinical trial of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) followed by radiation therapy (RT) versus ABVD alone for stages I, II, and IIIA nonbulky Hodgkin disease. Blood. 2004;104:3483-9. Laskar S, Gupta T, Vimal S, et al. Consolidation radiation after complete remission in Hodgkin’s disease following six cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy: is there a need? J Clin Oncol 2004;22: 62-8. Nachman JB, Sposto R, Herzog P, et al. Randomized comparison of low-dose involved-field radiotherapy and no radiotherapy for children with Hodgkin’s disease who achieve a complete response to chemotherapy. J Clin Oncol 2002;20 :376571. Meyer RM, Gospodarowicz MK, Connors JM, et al. Randomized comparison of ABVD chemotherapy with a strategy that includes radiation therapy in patients with limited-stage Hodgkin’s lymphoma: National Cancer Institute of Canada Clinical Trials Group and the Eastern Co-operative Oncology Group. J Clin Oncol 2005;23: 4634-42. Martin R. Weihrauch, Daniel Re, Klemens Scheidhauer et al. Thoracic positron emission tomography using 18F-fluorodeoxyglucose for the evaluation of residual mediastinal Hodgkin disease. Blood 2001;98: 2930-4. NG Mikhaeel, M. Hutchings, P. A. Fields et al. FDG-PET after two to three cycles of chemotherapy predicts progression-free and overall survival in high-grade non-Hodgkin lymphoma. Ann Oncol 2005;16: 1514-23. Hutchings M, Loft A, Hansen M et al. FDG-PET after two cycles of chemotherapy predicts treatment failure and progression-free survival in Hodgkin lymphoma. Blood 2006;107: 52-9. Gallamini A, Rigacci L, Merli F et al. The predictive value of positron emission tomography scanning performed after two courses of standard therapy on treatment outcome in advanced stage Hodgkin's disease. Haematologica 2006;91: 475-81. Franklin J, Pluetschow A, Paus M et al. Ann Oncol 2006 17: 1749-60. Ferme C, Eghbali H, Hagenbeek A et al. MOPP/ABV hybrid and irradiation in unfavourable supradiaphragmatic clinical stage I-II Hodgkin’s disease : comparison of three treatment modalities. Preliminary results of the the EORTC/GELA H8U randomized trial in 955 patients. Blood 2000;96:Abstract 576. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 69 | Hodgkin’s Lymphoma Treatment of relapsing/refractory patients with Hodgkin lymphoma P. Brice Hôpital Saint Louis, Paris, France Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:70-75 espite major improvements in the cure rate for Hodgkin’s disease (HD), 10 to 15% of patients with localized and 25 to 30% with disseminated classical Hodgkin lymphoma (HL) fail to respond or relapse after primary conventional treatment with chemotherapy alone or combined with radiotherapy.1,2 Distinctions must be made between refractory patients or induction failure, defined as disease regression of less than 50% after 4 to 6 cycles of anthracyclines containing chemotherapy (CT) or disease progression during induction treatment or within 90 days after the end of first line treatment. These refractory patients represent 2 to 5% of stage I/II and 5 to 10% of stage III/IV: These rates are lower than those in regimens like the increased-dose BEACOPP developed by Diehl for the GHSG.3 In all series, refractory patients have a poorer outcome than those achieving a complete remission.2 Relapsing patients will receive second line chemotherapy but the controversy surrounding the optimal timing (first vs second relapse) of autologous stem cell transplantation (ASCT) has largely subsided despite the benefits shown in a large randomised study.4 Radiation therapy (RT) is often omitted in first line treatment,5,6 on the contrary RT may have an increase place in relapsing patients.7 Some other patients with refractory disease or early and advanced relapse maintain a poor prognosis and for these patients an intensive regimen with tandem HDT and ASCT or allogeneic transplant can be proposed.8,9 D Prognostic factors at relapse Since1990, many mostly retrospective publications, have shown some adverse prognostic factors at relapse including advanced stage, time to relapse, B symptoms, and extranodal disease.1,10 In the largest series to date, Josting et al. from the GHSG developed a prognostic score for relapsed HL based on the outcome of 471 patients who failed initial therapy.11 In | 70 | multivariate analysis, independent risk factors were time to relapse (″ 12 mths. vs > 12 mths), clinical stage at relapse (stage III/IV) and anemia at relapse (males <12 g/L; females <10.5 g/L). FF2F were estimated at 45%, 32% and 18% for patients with prognostic scores of 0-1, 2, and 3 respectively. We therefore used only 2 adverse prognostic factors on a French series of patients receiving HDT and ASCT for first relapse of HL.12 For 214 patients in first relapse, we analyzed two significant prognostic factors, the interval between the end of treatment and relapse and the site of relapse (nodal versus EN). Three subgroups were defined: 0 factor (n=59), 1 factor (n=125), 2 factors (n=30). Their OS rates at 4 years were respectively, 93, 59 and 43%, and differed significantly (p<0.001). Moskowitz et al., presented one of the first prospective study in second line treatment for HL and identified 3 factors before the initiation of relapse treatment that predicted for outcome: B symptoms, extranodal disease, and complete remission duration of less than one year.12 EFS rates in intention to treat were 83% for patients with 0-1 factor, 27% for patients with 2 factors and 10% for patients with 3 factors. In 1997, a French prospective multicentric trial was started in 245 patients at first HL relapse/progression. Patients were stratified according to 2 prognostic factors at relapse (interval between the end of treatment and first progression before 12 months and stage III/IV at relapse or relapse in previously irradiated site) in 2 groups: - Poor prognosis risk relapse with the 2 adverse prognostic factors or primary refractory disease; - Intermediate risk relapse with only one factor. Results confirmed our prognostic model with 2 factors. At a median follow-up of 51 months, event free survival is at 46% in the poor risk group (n=150) and 76% in the intermediate risk group (n=95). Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 1 Table 1. Salvage chemotherapy in HL. Linch Brice Rodrigues Moskowitz Schmitz Ferme Josting Regimen Mini-BEAM IVA ASHAP ICE dexaBEAM MINE DHAP No. Year ORR of patients of publication 55+ 43° 56 65 161+ 83 57 1993 1999 1999 2001 2002 2002 2005 82% 60% 66% 88% 80% 74% 80% EFS 53 vs 10% 45% at 2 yrs 35% 58% at 3 yrs 55% at 3 yrs* Vs 34% 0.8 Survival Probability Author 0.6 0.4 0.2 0 0 46% at 4 yrs 25% at 2yrs +Randomization for HDT° refractory and early relapse; * for patients receiving HDT and ASCT. Grupe 1 Grupe 2 Logrank p>0.0001 20 40 60 80 1000 months Group 1 Group 2 No. of Subjects Event 150 53% (79) 95 25% (24) Censored 47% (71) 75% (71) Median Survival (95% CL) 40.8 (18.0 NA) NA (63.5 NA) Overall survival is at 57% versus 85%. (Morschhauser et al. submitted for publication) (Figure 1). Figure 1. EFS in relapsing HL patients according to stratification risk groups (group 1: poor risk group, group 2: intermediate risk group), the French GELA/SFGM prospective study. Salvage chemotherapy regimens No randomized trials exist to compared the effectiveness of salvage regimens in second line treatment for HL. These regimens have been various according to the initial regimen given. Most patients are now treated with ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) and cannot receive second line chemotherapy with doxorubicin if the cumulative dose is at 400 mg/m2. Intensive pretransplant regimens such as mini-BEAM (carmustine, etoposide, cytatbine, melphalan) and dexaBEAM (dexamethasone, carmustine, etoposide, cytarabine, melphalan) have a significant hematologic toxicity and a death rate of 2-5%, that is similar to rates seen with HDT and ASCT.4,14 Most other centers have used platinumbased regimens such as DHAP (dexamethasone, high-dose cytarabine, cisplatin), ASHAP (doxorubicin, methylprednisolone, high-dose cytarabine, cisplatin) or ifosfamide/etoposide-based regimens as MINE (mitoguazone, ifosfamide, vinorelbine, etoposide), IVA (ifosfamide, etoposide, doxorubicin), ICE (ifosfamide, carboplatin, etoposide).2,8,11,13,15 Results with overall response rate (complete response and partial response > 50%) of some prospective salvage regimens are presented in Table 1. Response rates ranged from 60 to 80%. Comparison of results is difficult due to the difference in prognostic groups with patients having refractory disease, early, late and multiple relapse. Response rate to salvage chemotherapy is different according to prognostic factors at relapse. With the MINE regimen, the overall response rate was at 60% for induction failure versus 89% for relapsing patients.2 The ideal salvage regimen should not add cumulative non hematologic toxicity (for example, cardiac or pulmonary) because this may lead to chemosensitivity which is always correlated to improved event free survival. Patients should be evaluated early after 2 cycles of pretransplant regimen and the regimen must be changed if the response is in below partial response. Due to its lower efficacy and higher toxicity, MOPP is not used in first line therapy but can be considered for use at relapse if a peripheral blood progenitor-cell collection (PBPC) is planned.16 BEACOPP standard or increased dose can also be useful as second line therapy.3 Radiation therapy Josting reported the most important study in this setting of salvage RT alone in 100 patients with primary progressive or relapsed HL.7 With a median observation time of 52 months, 5 year FFTF and survival were 28 and 51% respectively. Involved field RT can also be given after HDT with BEAM regimen and ASCT. This is important for patients with relapsed/ refractory disease and bulky mediastinal involvement. RT can be included in the conditioning regimen using accelerated fractionation radiotherapy either as total lymphoid irradiation (TLI) or as an involved field followed by high-dose chemotherapy and bone marrow infusion.17 One hundred and fiftysix patients were treated from 1985 to 1994. At a median follow-up of 7 years, the EFS rate is 42%, and no relapses have occurred later than 36 months after transplantation. This strategy was confirmed in 65 prospective patients with refractory (n=22) or relapsed (n=43) HL.13 PBPC from responding patients to ICE were collected, and the patients were given accelerated fractionation involved field radiotherapy (IFRT) followed by cyclophosphamide-etoposide and either intensive accelerated fractionation total lymphoid irradiation or carmustine and ASCT. The EFS rate at a median follow-up of 43 months, as analyzed Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 71 | 12th Congress of the European Hematology Association Table 2. High-dose therapy and ASCT, a selection of large retrospective studies. Year Author Status of disease 1993 Bierman Relapse IF Number Conditioning EFS FFTF Survival 128 CBV 25% 45% at 5 yrs Relapse 280 BEAM 60% 60% 66% at 4 yrs 1997 EBMT Relapse Sweetenham 139 BEAM 58% 45% 50% at 5 yrs 1999 EBMT Sweetenham IF 175 BEAM 47% 32% 36% at 4 yrs 1999 André IF 86 BEAM 51% 25% 35% at 5 yrs 2001 Sureda FirstCR Relapse IF 494 CBV 53% 45% 54% at 5 yrs Relapse IF 184 1997 Brice 2004 Popat NA 29% 34% at 10 yrs IF: Induction failure. by intent to treat, was 58%.This prospective study also demonstrates the efficacy and feasibility of integrating higher-dose radiotherapy into an ASCT treatment program. High dose therapy and autologous stem cell transplantation Results The use of HDT and ASCT is now considered the standard of care for most patients with refractory and relapsed HL. Two randomized trials in this setting showed a significant benefit in freedom from second failure. The first, published in 1993, was a BNLI trial comparing relapsed HL a salvage regimen miniBEAM alone or followed by HDT (BEAM) and ASCT in 40 patients. Despite the small numbers, there was a significantly improved 3-year EFS (53% vs 10%) and the trial ended prematurely.14 A similar trial was conducted by the GHSG and the EBMT with more patients. It consisted of an upfront randomisation, dexaBEAM was used as pretransplant regimen, 2 cycles before restaging and patients received either 2 other cycles of DexaBEAM or stem cell harvest and BEAM HDT followed by autotransplant. In this trial, 161 patients were randomised (21% with multiple relapse) but the dexaBEAM regimen was very toxic and only 117 chemosensitive patients could receive the procedure and are evaluable for the randomisation. Freedom from treatment failure (FFTF) at 3 years was significantly better for patients given BEAM-HDT (55% vs 34%) but no differences were observed in survival even with an update at ASCO 2005 with 7-year survival rates.4 The lack of survival difference in these two trials is difficult to interpret and may be related to the fact that most patients received HDT and ASCT for subsequent relapses. Some of the most important retrospective series of HDT in relapse/refractory HL are shown on Table 2. Toxic deaths were always below 5%. Survival rates ranged from 25 to 60% for EFS and from 35 to 66% for overall survival and showed that disease status (chemosensitivity) before HDT and ASCT is the most important prognostic factor for final outcome.12,-14,18-22 Patients not achieving a complete remission after first line treatment (for example, induction failure) have the worse outcome when compared to relapse but high dose chemoradiotherapy regimen and ASCT can be associated with an EFS at 45%.23 Toxicity HDT and ASCT are associated with a prolonged exposure of patients to cytotoxic agents and may lead in young patients to an increase of late toxicities. In a study, by André et al. 464 patients receiving ASCT were matched with 1,164 patients receiving conventional treatment. With a follow-up of 3 years, results did not show an increase in secondary MDS/leukaemia, but an excess of solid tumors in patients receiving HDT.24 In multivariate analysis, the most important adverse prognostic factor was relapse and it appeared that the number of chemotherapy lines was responsible for exposing the patient to long term toxicity rather than the conditioning regimen itself. Another British Columbia study examined retrospectively 1,732 patients treated in their area during a 26 years period and analysed the occurrence of second are solid tumors, comparing the 202 patients who received HDT to others.25 The cumulative incidence of developing any second malignancy 15 years after therapy was 9% and did not differ between those receiving HDT or not. The same team analysed the long term toxicity of the first 100 patients that underwent HDT for HL. Fifty-three patients were still alive with a median follow-up of 11 years.26 The major cause of death was progression (35%), followed by treatment related-toxicity (17%), but among living patients Karnofsky was >90%. Another 47 further patients suffered hypogonadism (n=20), hypothyroidism (n=12), common infections (n=10), anxiety or depression (n=7) and cardiac disease (n=5). Tandem HDT and ASCT A French multicentric prospective study first presented results of tandem transplantation in patients selected for their poor prognosis (induction failure, early and disseminated relapse). The first conditioning regimen was a CBV mitoxantrone or a BEAM and the second included total body irradiation at 12 Gys in 6 fractions or Busulfan 16 then 12 mg/kg and highdose cytarabine and melphalan.8 Preliminary results on 43 patients with a median follow-up of 24 months | 72 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 showed that only 74% of patients received the tandem transplant with one toxic death. On intent to treat analysis the EFS was at 40% and the survival at 53%. Results will soon be published on 150 patients and have been presented at the EBMT 2005. They show a 5 year EFS of 46% (CI 37-54%) overall survival of 57% (CI 48-65%) with a 4% toxic death rate. Allogeneic stem cell transplantation The role of allogeneic stem cell transplantation (allo-SCT) in patients with relapsed or refractory HL has been highly controversial. However, several series have suggested that allo-SCT seems to be associated with a clinically significant graft-versus-HL effect and a lower relapse rate with respect to ASCT retrospective analyses.27,28 Transplantation demonstrated disappointing results with allo-SCT in HL because of an extremely high transplant-related mortality (TRM) that was mainly associated with acute and chronic graft-versus-host disease (GVHD) and concomitant infectious episodes. Akpek et al. reported no difference in relapse rates, EFS and survival for 53 patients undergoing allo-SCT compared to 104 patients having auto-SCT for relapsed HL.29 The recent emphasis on reduced intensity conditioning (RIC) with allogeneic transplant has renewed interest in the use of allo-SCT for relapsed/refractory HL.30 Many studies are limited in number of patients with HL and the follow-up is often short. In a recent prospective study of 40 patients from the Spanish group they reported with an RIC protocol (fludarabine 150 mg/m2 intravenously plus melphalan 140 mg/m2) a TRM at one year at 25%, with an EFS and survival at 2 years respectively at 32% and 48%.31 A graft versus-lymphoma effect has been suggested with reports of response to DLI following disease relapse or progression.29,31 Allo-RIC should be considered an effective therapeutic approach for patients who have had treatment failure with a previous autologous hematopoietic stem cell transplantation. New agents Monoclonal antibodies The search for effective monoclonal antibodies for HL has not been as successful as in B-cell lymphomas. The target antigen has been mostly the CD30 which is expressed in all cases of classic HL and expression on normal tissue is limited. As reported ASH 2004, clinical activity of these antibodies, both chimeric or humanised has been disappointing. Other approaches to increase the benefit of targeted therapy include immunoconjugates and radiolabeled antibodies. The German study group treated 22 patients with relapsed/refractory HL with a murine anti-CD30 monoclonal antibody labelled with Iodine-131. Seven patients experienced grade 4 degrees hematotoxicity 4 to 8 weeks after treatment. Response included one complete remission and five partial remissions.32 The antiCD20 antibody rituximab has been seen to be active in nodular lymphocytic predominance HL but its activity in classic HL (even expressing CD20) has not yet been confirmed.33 Other areas will be explored in the use of immunoconjugates or with the association of monoclonal antibodies and chemotherapy. Chemotherapy agents The good prognosis of HL doesn’t encourage the search for new chemotherapeutic agents and patients are exposed very late to experimental drugs. Gemcitabine has been widely used in relapsed HL. A phase II study which enrolled 23 patients found a response rate of 39% with 9% of complete remission and a median duration of response at 6.7 months.34 Vinorelbine has shown efficacy in HL and is included in the relapse protocol of the GELA group for HL with the MINE regimen.2 Presented at the EHA 2006, our results with eloxatine combined with ifosfamide and etoposide showed a 66% response rate in 25 relapsed/ refractory HL patients with a low toxicity profile. Results were, however, disappointing in refractory patients. Therapeutic guidelines for patients relapsing after ABVD (alone or combined modality) Our guidelines are based on 2 simple prognostic factors: - the time to relapse; - nodal and outfield site. Other parameters can be taken account such as Bsymptoms or low hemoglobin level to include patients in the poor prognosis group.10,11 Response to second line therapy should be monitored on FDGPET scans which are very efficient in HL.35 Favorable relapse This group represents those rare and occurring at least one year after the end of first line treatment. These patients can be treated with conventional doses of chemotherapy and we suggest a standard chemotherapy like BEACOPP or MOPP/ABV rather than second line ABVD to avoid cumulative doses of doxorubicin > 400 mg/m2 (with particular caution for patients who have also received mediastinal RT).3,36 The number of cycles may range from 4 to 6 according to toxicity and response and should be followed by involved field RT (30/36 Gys). Intermediate risk relapse Patients with only one adverse prognosis factor should receive HDT with ASCT due to the excellent results of this procedure in this setting with a possi- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 73 | 12th Congress of the European Hematology Association bility of cure with an acceptable toxicity.12,19 Pretransplant regimens should avoid cumulative doses of doxorubicin and aim to obtain chemosensitivity before HDT, for example, in this intermediate group CRu with negative FDG-PET scans. All the regimens previously described are suitable for consideration. If an initial response is not satisfactory a second line regimen should be given to increase response. Most of these regimens can achieve PBPC mobilisation. BEAM is the most widely used conditioning regimen in relapsed lymphoma and there is no data supporting the use of TBI in this setting.37 By contrast, involved field RT can be given after HDT in nodal sites of relapse, generally if bulky (mediastinum). Poor prognosis relapse This is the largest group and includes: - induction failure or refractory patients; - poor prognosis relapse at least early and extranodal or stage IIIB or with significative anemia. For those patients who received no more than 6 cycles of ABVD, we suggest treating them with increased-dose BEACOPP 2 to 3 cycles as second line regimen.3 This regimen can mobilize PBSC and represent one of the most effective polychemotherapies in advanced HL. But it is associated with significant toxicity. For other patients second line regimens include those previously described, such as platinumbased regimens or ifosfamide/etoposide regimens. The aim is to achieve at least a partial response > 50% before HDT. We suggest performing tandem HDT for patients not in CR before first HDT. In some cases when an HLA identical donor is available, RIC-alloSCT can be discussed.8,37 The first HDT aims to induce a complete remission and the second HDT to prevent relapse. But often refractory patients progress early after HDT. In these cases, they should proceed to experimental therapies. Multiple relapses Despite improvements in first and second line treatment, some patients continue to relapse and need further treatment. For patients relapsing less than one year after HDT, RIC-allo could be offered when an HLA identical donor is available and if a good response has been achieved with third line regimen. For the remaining patients third line regimens should use different drugs to avoid cumulative toxicity from doxorubicine or beomycin and RT can be given in the relapse outfields. All data regarding second auto-SCT for relapsed HL are from general observations with small series and an increased rate of late treatment related mortality. This option should, therefore, be limited to patients, who achieved a long CR after their first transplant.38 Conclusions There is an increased possibility of cure among patients with relapsed HL this can be estimated at approximately 50% with HDT and ASCT. All results are improved in chemosensitive patients and late relapses. Despite this relatively favourable prognosis for a relapsing malignancy, further attempts to improve the outcome of these patients should be made. New approaches are needed for chemoresistant HL where there is a less than 30% chance of long-term remission even with auto or allo-SCT. The data of allo-SCT are preliminary and limited by the chemosensitivity required before procedure before an allogeneic effect is seen. The search for new drugs in this setting is important but problematic and patients with HL enter protocols very late due to the usually good disease prognosis. Relapsing HL patients are also more exposed to long term toxicity for example, second malignancies and cardiac toxicity, and the objective shoul be the early identification of poor responders. References 1. Lohri A, Barnett M, Fairey RN et al: Outcome of first relapse of Hodgkin's disease after primary chemotherapy : identification of risk factors from the British Columbia experience 1970 to 1980. Blood 1991, 77: 2292-8. 2. Fermé C, Mounier N, Diviné M et al. Intensive salvage chemotherapy with high-dose chemotherapy for patients with advanced HD in relapse or failure after initial chemotherapy: results of the GELA H89 trial. J Clin Oncol 2002, 20:46775. 3. Diehl V, Franklin J, Pfreundschuh M, Lathan B, Paulus U, Hasenclever D, et al. Standard and increased-dose BEACOPP chemotherapy compared with COPP-ABVD for advanced Hodgkin’s disease. N Engl J Med 2003; 348:2386-95. 4. Schmitz N, Pfistner B, Sextro M et al. Aggressive conventional chemotherapy compared with high-dose chemotheroy with ASCT for relapsed chemosensitive Hodgkin’s disease: a randomised trial. Lancet 2002;325:2065-71. 5. Fermé C, Sebban C, Hennequin C et al. Comparison of chemotherapy to radiotherapy as consolidation of complete response after 6 cycles of chemotherapy for patients with advanced HD: results of the GELA H89 trial. Blood 2000;95 :2246-52. 6. Aleman BMP, Raemakers J, Tirelli U et al. Involved field radiotherapy for advanced Hodgkin lymphoma. N Engl J Med 2003;348:2396-406. 7. Josting A, Nogova L, Franklin J, Glossmann, Eich HT, Sieber M et al. Salvage radiotherapy in patients with relapsed and refractory Hodgkin’s lymphoma: a retrospective analysis from the German Hodgkin lymphoma study group. J Clin Oncol 2005;23:1522-9. 8. Brice P, Diviné M, Simon D et al. Feasibility of tandem ASCT in induction failure or very unfavorable relapse from Hodgkin’s disease. Ann Oncol 1999;10:1485-88. 9. Anderlini P, Saloba R, Acholonu S, et al. Reduced-intensity allogeneic stem cell transplantation in relapsed and refractory Hodgkin’s disease: low transplant-related mortality and impact of intensity of conditioning regimen. Bone Marrow transplant 2005;35:943-51. 10. Brice P, Bastion Y, Diviné M et al. Aanalysis of prognostic factors after the first relapse of Hodgkin's disease in 187 patients. Cancer, 1996;78:1293-9. 11. Josting A, Rueffer U, Franklin J, et al: Prognostic factors and treatment outcome in primary progressive Hodgkin lymphoma: a report from the German Hodgkin Lymphoma Study Group. Blood 2000;96:1280-6. 12. Brice P, Bouabdallah R, Moreau P et al. Prognostic factors for | 74 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. survival after high-dose therapy and ASCT for patients with relapsing Hodgkin's disease: analysis of 280 patients from the French registry. Bone Marrow Transplant 1997;20:21-6. Moskowitz CH, Nimer SD, Zelenetz AD et al. A 2 step comprehensive high-dose chemoradiotherapy second-line program for relapsed and refractory Hodgkin disease: analysis by intent to treat and development of a prognostic model. Blood 2001;97:616-23. Linch DC, Winfield D, Goldstone AH et al: Dose intensification with ABMT in relapsed and resistant Hodgkin's disease, results of a BNLI randomised trial. Lancet 1993;341:1051-4. Rodriguez J, Rodriguez MA, Fayad L et al. ASHAP: a regimen for cytoreduction of refractory or recurrent Hodgkin’s disease. Blood 1999;93:3632-6. Canellos GP, Anderson JR, Propert KJ et al. Chemotherapy of advanced Hodgkin’s disease with MOPP, ABVD or MOPP alternating with ABVD. New Engl J Med 1992;327:1478-84. Yahalom J, Gulati SC, Toia M, et al. Accelerated hyperfractionated total-lymphoid irradiation, high-dose chemotherapy, and autologous bone marrow transplantation for refractory and relapsing patients with Hodgkin’s disease. J Clin Oncol. 1993;11:1062-70. Sureda A, Arranz R, Iriondo E et al. ASCT for Hodgkin’s disease: results and prognostic factors in 494 patients from the spanish cooperative group. J clin Oncol 2001;19:1395-404. Sweetenham JW, Taghipour G, Milligan D et al. HDT and ASCT for patients with Hodgkin’s disease in first relapse after chemotherapy , a report of the EBMT. Bone Marr Transplant 1997;20:745-52. Andre M, Henry-Amar M, Pico JL, Brice P, Blaise D, Kuentz M, et al. Comparison of high-dose therapy and ASCT with conventional therapy for Hodgkin’s disease induction failure: a case control study. J Clin Oncol 1999;17:222-9. Sweetenham JW, Carella AM, Taghipour G et al. HDT and ASCT for patients with Hodgkin’s disease who do not enter into complete remission after induction chemotherapy : results of 175 patients reported to the EBMT. J Clin Oncol 1999;17: 3101-9. Popat U, Hosing C, Salibat RM et al. Prognostic factors for disease progression after HDT and ASCT for recurrent or refractory Hodgkin lymphoma. Bone Marr Transplant 2004,33: 1015-23. Moskowitz cH, Kewalramani T, Nimer SD et al. Effectiveness of high-dose chemoradiotherapy and ASCT for patients with biopsy-proven primary refractory Hodgkin’s disease. Br J Haematol 2004;124:645-52. André A, Henry-Amar M, Blaise D et al. Treatment related deaths and second cancer risk after ASCT for Hodgkin disease. Blood 1998;82:1933-40. Forrest DL, Hogge DE, Nevill TJ et al. HDT and ASCT does not increase the risk of second neoplasms for patients with Hodgkin lymphoma: a comparison of conventional therapy alone versus conventional therapy followed by ASCT. J Clin Oncol 2005;23:7994-8002. Lavoie JC, Connors JM, Philips GL et al. HDT and ASCT for relapsed and refractory Hodgkin lymphoma, long term out- come of the first 100 patients transplanted in Vancouver. Blood 2005;106:1473-9. 27. Milpied N, Fielding AK, Pearce RM et al. Allogeneic bone-marrow transplant is not better than autologous for patients with relapsed HD. From the EBMT. J Clin Oncol 1996;14: 1291-96. 28. Gajewski JL, Philips GL, Sobocinski KA et al. Bone marrow transplants from HLA-identical sibilings in advanced Hodgkin’s disease. J Clin Oncol 1996;14:572-8 29. Akpek G, Abinder RF, Piantadosi A et al. Long-term results of blood and marrow transplantation for Hodgkin’s lymphoma. J Clin Oncol 2001;19:4314-21. 30. Khouri IF, Keating M, Korbling M et al. Transplant-lite: induction of graft-versus-malignancy using a fludarabine-based nonablative chemotherapy and allogeneic blood progenitor cell transplantation as treatment for lymphoid malignancies. J Clin Oncol. 1998;16:2817-24. 31. Alvarez,I, Sureda,A, Caballero Md et al. Nonmyeloablative Stem Cell Transplantation is an effective therapy for refractory or relapsed Hodgkin Lymphoma: results of a Spanish Prospective Co-operative Protocol. Biology of Blood and Marrow Transplantation 2006;12:172-83 . 32. Schnell R, Dietlein M, Staak JO et al. Treatment of refractory Hodgkin lymphoma: patients with an Iodine-131 labeled murine anti-CD30 monoclonal antibody. J Clin Oncol 2005;23:4669-78. 33. Rehwald U, Schulz H, Reiser M, Sieber M, Staak JO, Morschhauser F, et al. Treatment of relapsed CD20+ Hodgkin lymphoma with the monoclonal antibody rituximab is effective and well tolerated results of a phase 2 trial of the German Hodgkin Lymphoma Study Group. Blood 2003;101:420-4. 34. Santoro A, Bredenfeld L, Devizzi L et al. Gemcitabine in the treatment of refractory Hodgkin’s disease : results of a multicenter phase II study. J clin Oncol 2000;18:2615-9. 35. Schot BW, Zijlstra JM, Sluiter WJ et al. Early FDG-PET assessment in combination with clinical scores determines prognosis in recurring lymphoma. Blood 2007;109:486-91. 36. Connors JM, Klimo P, Adams G, Burns BF, Cooper I, Meyer RM, et al. Treatment of advanced Hodgkin’s disease with chemotherapy: comparison of MOPP/ABV hybrid regimen with alternating courses of MOPP and ABVD, a report from the NCI of Canada clinical trials group. J Clin Oncol 1997;15:1638-45. 37. Chopra AK, McMillan AK, Linch DC et al. The place of highdose BEAM therapy and ABMT in poor-risk Hodgkin's disease, a single center eight-year study of 155 patients. Blood 1993;81:1137-45. 38. Carella AM, Cavaliere M, Lerma E et al. Autografting followed by nonmyeloablative immunosuppressive chemotherapy and allogeneic HSC transplantation as treatment of resistant HD and NHL. J Clin Oncol 2000;18:3918-24. 39. Lin TS, Avalos BR, Penza SL et al. Second autologous stem cell transplantation for multiply relapsed Hodgkin ‘s disease. Bone Marrow Transplant 2002;29:763-7. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 75 | What’s New in T-cell non-Hodgkin’s Lymphomas? Pathology and genetics of T-cell lymphomas A. Chott A-I. Schmatz E. Kretschmer-Chott L. Müllauer B. Streubel Department of Pathology, Medical University of Vienna, Vienna, Austria Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:76-82 -cell neoplasms can be divided into two categories depending on the developmental stage of the lymphoma cell. Precursor T lymphoblastic leukemia/lymphoblastic lymphoma is a neoplasm of lymphoblasts committed to the T-cell lineage reflecting early, usually terminal deoxynucleotidyl transferase (TdT)-positive thymic developmental stages, whereas post-thymic or peripheral T-cell lymphomas display a morphologic appearance and phenotype consistent with mature T-cells. Because of some phenotypic and functional overlap between mature T-cells and natural killer (NK) cells, the neoplasms derived from these cell types are considered together in the WHO classification (Table 1).1 This review will concentrate on the more common mature, peripheral T-cell lymphomas (PTL) but also include some of the rare entities. In particular, the PTLs printed in bold type in Table 1 will be discussed in detail. Genetic analysis of these malignancies is required to identify pathogenetic genes which can define specific subtypes of disease. The first steps in this genetic analysis have already been taken and are summarized below. T General features of peripheral T-cell lymphomas Peripheral T-cell lymphomas are rare. They account for roughly 10% of all nonHodgkin lymphomas (NHL) on a worldwide basis.2 The most common subtypes are PTL, unspecified (PTL-u)(3.7%), and anaplastic large cell lymphoma (ALCL) (2.4%). In general, T-cell lymphomas are more common in Asia with the virus HTLV-1 representing the main risk factor for the development of adult T-cell leukemia/lymphoma (ATLL) in Japan. Nasal NK/T-cell lymphomas are also much more common in Asians than they are in other races, accounting for 8% of cases in Hong Kong, and show an association with Epstein-Barr virus.3 Enteropathy-type T-cell lymphoma arises against | 76 | the same genetic background as that predisposing to celiac disease and is therefore more common in Northern Europe.4 Classification of peripheral T-cell lymphomas PTLs are characterized by extreme morphologic diversity and this has compromised the formulation of a reproducible classification for many years. In 1994, the International Lymphoma Study group, proposed the Revised European-American Lymphoma (REAL) classification which grouped the T-cell and postulated NK cell lymphomas into clinical entities.5 The diverse histologic lesions that did not represent specific clinical entities were encompassed in the group of PTL-u. This classification was further refined in the WHO classification of PTL and NK cell lymphomas, which were divided into the three general groups, leukemic/disseminated, nodal, and extranodal, based on their clinical features1 as shown in Table 1. The characterization of entities included in this classification has integrated morphologic, clinical, immunophenotypic and genetic studies. Clinical features play a defining role in many PTLs As the cellular composition of PTLs can range from small cells with minimal atypia to large cells with anaplastic features, a spectrum of histologic appearances can be seen even within individual disease entities. Therefore cytologic principles have been difficult to apply for the classification of PTLs and their reproducibility was poor.6 Similarly, immunophenotyping has been less useful than in B-cell lymphomas since defining markers, such as cyclinD1 for mantle cell lymphoma, or marker combinations such as CD10/BCL6 for follicular lymphoma, are lacking. Finally, the molecular pathogenesis for most PTLs is as yet undiscovered. For these reasons, clinical features have played a major role in defining many of the specific entities included in the WHO classification (Table 2). Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Pathology of peripheral T-cell lymphoma, unspecified, angioimmunoblastic T-cell lymphoma, and anaplastic large cell lymphoma Peripheral T-cell lymphoma, unspecified Earlier studies have recognized a variety of morphologic subtypes based on cell size and cytology, including pleomorphic T-cell lymphoma, lymphoepithelioid lymphoma (Lennert's lymphoma), and Tzone lymphoma. However, no clinical or other substantial differences among these histologic types have emerged (Figure 1A, B). As a group these tumors account for approximately half the PTLs in Western countries. They usually present with advanced stage of disease and belong to the category of the most aggressive NHLs.2,7 Immunophenotypically, these cases express the αβ heterodimer of the T-cell receptor, more commonly CD4 than CD8, but a significant proportion of the cases have an aberrant phenotype (CD4–CD8–, or less commonly, CD4+CD8+) and show loss of CD5 and/or CD7.8-10 A very recent study has attempted to correlate PTLs with specific developmental stages of mature reactive T-cells.11 A major subset of PTLs-u was found to correlate with a non-effector, or central memory, Tcell population characterized by a CD45RA– CD45RO+CD27+CD4+ phenotype. In contrast, all angioimmunoblastic T-cell lymphomas (AITL) and Table 1. WHO classification of mature T-cell and NK-cell neoplasms (1). Mainly nodal Peripheral T-cell lymphoma, unspecified Angioimmunoblastic T-cell lymphoma Anaplastic large cell lymphoma Extranodal/Cutaneous Extranodal NK/T-cell lymphoma, nasal type Enteropathy-type T-cell lymphoma Hepatosplenic T-cell lymphoma Subcutaneous panniculitis-like T-cell lymphoma Cutaneous γδ T-cell lymphoma Mycosis fungoides Sezary syndrome Primary cutaneous anaplastic large cell lymphoma Often leukemic or disseminated T-cell prolymphocytic leukemia T-cell granular lymphocytic leukemia Aggressive NK-cell leukemia Adult T-cell lymphoma/leukemia (HTLV1+) ALCL showed a homogeneous effector cell phenotype CD45RA–CD45RO+CD27–. Nevertheless, in daily routine cases of PTL-u showing borderline features to AITL and to anaplastic lymphoma kinase (ALK)-negative ALCL exist and may cause problems that need to be solved. Table 2. Pathological and clinical characteristics of peripheral T-cell lymphomas and NK/T-cell lymphoma. Predominant clinical features Sites of involvement Predominant immunophenotype Prognosis Recurrent genetic abnormalities Peripheral T-cell lymphoma, unspecified Aggressive, often B-symptoms, advanced stage, IPI 3-5: 60% Lymph nodes, bone marrow, skin TCRa/β,CD3+CD2+ CD4+>CD8+. Often loss of CD5, CD7 Poor Complex karyotypes, Very small subset t(5;9)(q33;q22) Angioimmunoblastic T-cell lymphoma Generalized lymphadenopathy, hepatosplenomegaly, skin rash, hypergammaglobulinemia Lymph nodes, bone marrow, skin, lung TCRα/β,CD3+CD4+ CD10+CXCL13+CD8- Poor, +3,+5 5-year survival 30% Anaplastic large cell lymphoma Lymphadenopathy, B-symptoms Lymph nodes, skin, soft tissue, bone, lung CD30+ALK+CD3+ Favorable for TIA1+EMA+; ALK+ cases loss of many T-cell antigens t(2;5)(q23;q35) and variants Extranodal NK/T-cell lymphoma, nasal type Aggressive locally destructive Nose, nasal cavity, paranasal sinuses, pharyngeal tissue CD3ε+CD56+CD2+ TIA1+; CD4-CD5EBV+ Poor del 6q Enteropathy-type T-cell lymphoma Acute abdominal emergency, small bowel perforation, malabsorption, weight loss Upper jejunum, often multiple segments, mesenteric lymph nodes Type 1: CD56-CD3+ CD7+CD2+TIA1+ Type 2: CD56+CD8+ Very poor Gains 9q or losses 16q; Type 1: gains 1q, 5q Type 2: gains 8q24 Hepatosplenic T-cell lymphoma Young males, B-symptoms, hepatosplenomegaly, thrombocytopenia Liver, spleen, bone marrow TCRγδ, CD3ε+CD56+ TIA1+ CD5-CD4-CD8- Poor Isochromosome 7 Subcutaneous panniculitis-like T-cell lymphoma Solitary or multiple not ulcerated, Subcutaneous fatty tissue erythematous tumors s or plaques at extremities TCRα/β,CD3+CD2+ CD5+CD8+TIA1+CD5 CD56- 5-year survival 80% None Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 77 | 12th Congress of the European Hematology Association Angioimmunoblastic T-cell lymphoma AITL represents a distinctive PTL subtype with unique clinicopathological features sometimes simulating an infectious process. It usually effects the elderly and presents with generalized lymphadenopathy although lymph node enlargement may be not be as pronounced as in other primary nodal PTLs. Hepatosplenomegaly, skin rash and B-symptoms are often present as well as hypergammaglobulinemia and elevation of both the LDH and erythrocyte sedimentation rate. Patients may show anemia and occasionally pancytopenia. A significant proportion of patients have circulating autoantibodies and a number of autoimmune phenomena have been reported.12 Histologically, the lymph node architecture is at least partially effaced by a polymorphic infiltrate predominantly occupying the paracortical areas. Subcapsular sinuses may be preserved. The neoplastic T-cells have clear cytoplasm and are distributed in a marked inflammatory background comprising polyclonal plasma cells, eosinophils, epithelioid histiocytes, arborized high endothelial venules and expanded follicular dendritic meshworks (Figure 2). Extranodal disease may be present at diagnosis including involvement of the bone marrow, spleen, skin, and lungs. The neoplastic T-cells, which may be a minor cell population, are CD4+ T-cells that coexpress CD10 and sometimes BCL-6 suggesting the derivation from a unique population of T-cells, called follicular B helper cells (TFH) which are normally specialized in B-cell help within the germinal center microenvironment.12 More recently it was shown that in AITL the atypical CD10+ cells express CXCL13, a chemokine highly upregulated in TFH cells and critically involved in lymphoid organogenesis and B-cell migration into follicles.13,14 Finally, gene expression profiling revealed that the AITL molecular signature was significantly enriched for TFH cell-specific genes strongly supporting the idea that TFH cells represent the normal counterpart of AITL.15 Another frequent finding in AITL is the presence of EBV-infected B-cells even early in the course of the disease which may progress to an EBV-positive lymphoproliferative disorder. This may show both T-cell receptor and immunoglobulin heavy chain gene rearrangements when examined by clonality studies. Anaplastic large cell lymphoma Usually presents with nodal disease but may initially affect a variety of extranodal sites. The WHO provisionally included cases of ALCL positive and negative for ALK under the heading of ALCL. But ALK-negative cases differ in a number of respects. They are seen in an older age group, have a worse prognosis, and generally show greater nuclear pleomorphism. These findings suggest that ALK-negative Figure 1. Peripheral T-cell lymphoma, unspecified. Image A shows a representative case of peripheral T-cell lymphoma, unspecified, infiltrating the paracortical area, sparing a centrally located follicle remnant. At higher magnification, image B depicts diffusely infiltrating atypical large cells. Cytogenetics and molecular cytogenetics of another case demonstrate t(5;9)(q33;q22) and subsequent identification of ITK-SYK rearrangement, as found in a small subgroup of peripheral T-cell lymphoma, unspecified (C, D). Figure 2. Angioimmunoblastic T-cell lymphoma. Overview showing arborized vessels surrounded by a mixture of small, medium-sized, and a few large cells, some of which appear as clear cells with pale cytoplasm. Staining for CD21 reveals the typical enlarged network of proliferating follicular dendritic cells. Loose collections of CD10+ T-cells are present. ALCL will ultimatively represent a different disease entity with an independent pathogenesis.16 Several histologic variants of ALCL have been identified including the most frequent common type. This shows cohesively arranged large cells with lobulated, kidney-shaped nuclei and abundant grey-blue cytoplasm sometimes referred to as hallmark cells17(Figure 3). The small cell variant may be diagnostically highly challenging because of similarities with an inflammatory process. Identification of neoplastic cells require immunoreactivity for CD30 and ALK particularly in | 78 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Figure 3. Anaplastic large cell lymphoma, ALK positive. Sinusoidal infiltration of cohesively arranged anaplastic tumor cells, demonstrating cytoplasmic and nuclear reactivity for ALK indicating t(2;5). this ALCL variant and similarly in the lymphohistiocytic variant in which histiocytic cells may obscure the neoplastic population.16,17 Another variant is Hodgkin-like ALCL which most often represents an aggressive variant of classic Hodgkin lymphoma and shows overlap with mediastinal grey-zone lymphomas.18 Immunophenotypically ALCL is characterized by positivity for CD30, and in 60-85% of the cases, for ALK. The frequent reactivity for T-cell intracellular antigen (TIA-1) and epithelial membrane antigen (EMA) is also diagnostically helpful. Loss of several or even all T-cell associated antigens is a typical feature of ALCL. Defective expression of T-cell receptors in all types of ALCL (ALK+, ALK–, cutaneous) separates these tumors from other PTLs and may contribute to the dysregulation of intracellular signaling pathways controlling T-cell activation and survival.19 Primary cutaneous ALCL is a different disease entity belonging to the spectrum of the primary cutaneous CD30+ T-cell lymphoproliferative disorders. It differs from the systemic forms (ALK+ and ALK–) in its site of origin, its clinical features, and almost invariable absence of ALK protein and EMA.16 Genetics of anaplastic large cell lymphoma, peripheral Tcell lymphoma unspecified, and angioimmunoblastic T-cell lymphoma From the genetic point of view, ALCL is the only well characterized PTL as the vast majority of cases have the t(2;5)(p23;q35) involving the ALK tyrosin kinase and the nucleophosmin gene, resulting in overexpression of a chimeric oncogene, nucleophosmin/ anaplastic lymphoma kinase (NPM/ALK).20 NPM/ALK activates numerous downstream signaling pathways resulting in enhanced survival and proliferation. Over 11 variant translocations involving the ALK gene have been described in lymphomas and a subset of pediatric tumors, including inflammatory myofibroblastic tumor and rhabdomyosarcoma. This shows that the transforming potential of ALK tyrosine kinase is manifest in more than one cell type. Very recent proteomic studies may provide the basis for the identification of biomarkers and targets for novel therapeutic agents.21 The molecular alterations underlying the pathogenesis of AITL and PTL- are largely unknown. The overexpression of several TFH genes, as shown by gene expression profiling, supports the idea that AITL is derived from TFH cells.15 However, the spectrum of AITL may be wider than suspected, and, in contrast to AITL and ALCL, PTL-u does not share a single molecular profile .15,22 A comparison of the gene expression pattern of PTL with that of normal T-cells revealed that PTL-u display deregulation of functional programs often involved in tumorigenesis, such as apoptosis, proliferation, cell adhesion, and matrix remodeling. Furthermore, PTLs-u aberrantly express, among others, PDGFRα, a tyrosine kinase receptor whose deregulation is often related to a malignant phenotype.23 With the notable exception of the t(2;5) and its variants in ALCL, no recurrent chromosomal translocations were known to occur in PTLs until Streubel et al. recently reported on the identification of a novel recurrent t(5;9)(q33;q22) in a small subset of PTLs-u24 (Figure 1 C,D). Four of five translocation-positive cases among a total of 30 PTLs-u examined demonstrated a follicular or perifollicular growth pattern indicating a tropism of the lymphoma cells to lymphoid follicles. Cases of AITL and ALK-negative ALCL were negative for the t(5;9). Molecular analysis revealed breaks within the ITK gene on chromosome 5 and SYK on chromosome 9 generating an ITK-SYK fusion transcript. The result of the translocation is likely to be activation of SYK through overexpression, driven by the ITK promoter. Interestingly, the neoplastic cells in three of the four t(5;9)+ cases with follicular growth pattern were CD4+CD10+BCL6+ and thus closely resembled the immunophenotype described for TFH in AITL. Pathology and genetics of extranodal NK/T-cell lymphoma, nasal type Extranodal NK/T-cell lymphoma, nasal type, is a distinct clinicopathologic entity highly associated with EBV. The disease is rare in Western countries but more prevalent in Asia and in South and Central America. The most common clinical presentation is a destructive nasal or midline facial lesion resulting in nasal obstruction or epistaxis. The lymphoma can extend to adjoining tissues such as paranasal sinuses, nasopharynx, palate, oropharynx, oral cavity, and orbit. In most of the cases the disease is localized to Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 79 | 12th Congress of the European Hematology Association Type 1 Type 2 Figure 4. Enteropathy-type T-cell lymphoma. In this example Type 1 is characterized by anaplastic large cells, whereas Type 2 shows a monomorphic infiltration of a jejunal villous tip with small, CD56 positive lymphoid cells. the upper aerodigestive tract at presentation and bone marrow involvement is very uncommon.25 Nevertheless, the disease may disseminate and may be complicated by a hemophagocytic syndrome. Histologically an angiocentric growth pattern is often present, and the cytological spectrum is very broad. Cases predominantly composed of small cells may mimick an inflammatory processs. Immunophenotypically NK/T-cell lymphoma is characterized by CD2+CD56+ and cytoplasmic CD3ε-chain expression and positivity for cytotoxic granules-associated proteins such as TIA-1, granzyme B, and perforin.26 The expression of granzyme M identifies these cells as belonging to the innate arm of the immune system which is independent of specific antigen activation.27,28 Other T-cell associated antigens are usually negative and T-cell receptor genes are not rearranged. True NK cell lymphomas more often express NK cell receptor molecules such as CD94/NKG2A29 and CD94 expression has been reported to imply a better prognosis.30 The demonstration of EBV encoded small nuclear mRNA (EBER) by in situ hybridization is positive in almost all cases and therefore is very useful diagnostically.31 Various genetic alterations may occur in nasal type extranodal NK/T-cell lymphoma. Deletions at 6q are the most common. However their significance is as yet unknown.32 Pathology and genetics of enteropathy-type T-cell lymphoma Enteropathy-type T-cell lymphoma (ETTCL) is a rare, primary intestinal lymphoma arising from intraepithelial T-cells, usually as a consequence of clinically unknown celiac disease. The proximal jejunum is the most frequent site of disease, although it may occur elsewhere in the small intestine and, rarely, in the stomach and colon.33 About 40% of patients present as acute abdominal emergencies due to intestinal perforation and/or obstruction. Patients may have a short history of malabsorption, sometimes diagnosed as adult celiac disease which is often gluten-insensitive or, less frequently, a long history of celiac disease lasting for years or even decades. Histologically most cases are composed of pleomorphic medium to large cells or show features resembling anaplastic large cell lymphoma, mostly carrying the immunophenotype CD3+CD7+CD5–CD4–CD8– TIA1+CD56– (type 1 ETTCL). A minority of cases (10-20%) consists of monomorphic small to medium-sized cells which often express CD8 and CD56 (type 2 ETTCL, Figure 4).33,34 Type 1 and type 2 ETTCL also differ biologically and by their genetic profile. Type 1 is linked to celiac disease by virtue of expressing HLADQ2 or DQ8, and is characterized by chromosomal gains of 1q and 5q. In contrast, type 2 rarely shows the genetic background of celiac disease but more often gains of the MYC oncogene locus at 8q24.35,36 The common genetic denominator of both EATTCL types, and hence the genetic hallmark of the disease present in about 70% of cases, is gain at the long arm of chromosome 9, while, to a much lesser extent, loss at 16q is observed.35,37 To understand the pathogenesis of ETTCL it is nessessary to recognize the role of refractory celiac disease as an in situ ETTCL. A small fraction of adult celiac disease patients fail to improve after a glutenfree diet, show persisting villous atrophy and an increase of monoclonal, immunophenotypically unusual intraepithelial lymphocytes, usually showing loss of CD8.38,39 This group of patients is referred to as having refractory celiac disease II (RCD II) as opposed to RCD I who show polyclonal and immunologically normal intraepithelial lymphocytes.40 Patients diagnosed with RCD II are thought to suffer from cryptic intraepithelial (in situ) ETTCL associated with a poor prognosis and high risk of progression to overt invasive lymphoma. Interestingly, Verkarre et al. have demonstrated that intraepithelial lymphocytes of patients with RCD II carry gains of chromosome 1q. This has also been observed in the frequently celiac disease-associated type 1 ETTCL.41,35 Therefore several lines of evidence support the hypothesis that RCD II represents a precursor lesion of overt ETTCL and deserves a designation such as in situ ETTCL. Pathology and genetics of hepatosplenic T-cell lymphoma Hepatosplenic T-cell lymphoma (HSTCL) is an extranodal and systemic neoplasm derived from cytotoxic T-cells, usually the γ/δ T-cell receptor type. It is a rare and aggressive malignancy predominantly affecting young men.42,43 The patients present with | 80 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 thrombocytopenia and isolated hepatosplenomegaly due to marked sinusoidal infiltration of mediumsized cells with pale cytoplasm. Lymphadenopathy or significant peripheral blood involvement are usually absent, but there is sinusoidal infiltration of the bone marrow. Cytogenetically, isochromosome 7q is reported to be the primary genetic abnormality.44 Pathology of subcutaneous panniculitis-like T-cell lymphoma According to the WHO-EORTC classification for cutaneous lymphomas, subcutaneous panniculitislike T-cell lymphoma (SPLTCL) is a cytotoxic T-cell lymphoma with an α/β CD8+ T-cell phenotype presenting with primarily subcutaneous infiltrates of pleomorphic T-cells and many macrophages, predominantly affecting the extremities.45 A long history of benign panniculitis may be observed. In contrast to prior reports indicating that SPLTCL patients have a rapidly fatal course, recent studies suggest that many patients run a protracted clinical course.46 Constitutional symptoms, and particularly a hemophagocytic syndrome, are more typical for mucocutaneous γ/δ Tcell lymphoma which has to be separated from SPLTCL. No recurrent chromosomal aberration has been reported. References 1. Jaffe ES, Harris NL, Stein H, Vardiman J. Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: IARC Press; 2001. 2. The Non-Hodgkin's Lymphoma Classification Project. A clinical evaluation of the International Lymphoma Study Group Classification of non-Hodgkin's lymphoma. Blood 1997;89: 3909-18. 3. Anderson JR, Armitage JO, Weisenburger DD. Epidemiology of the non Hodgkin's lymphomas: distributions of the major subtypes differ by geographic locations. Non-Hodgkin's Lymphoma Classification Project. Ann Oncol 1998;9:717-20. 4. Howell WM, Leung ST, Jones DB, Nakshabendi I, Hall MA, Lanchbury JS, et al. HLA-DRB, -DQA, and -DQB polymorphism in celiac disease and enteropathy-associated T-cell lymphoma. Common features and additional risk factors for malignancy. Hum Immunol 1995;43:29-37. 5. Harris NL, Jaffe ES, Stein H, et al. A revised EuropeanAmerican classification of lymphoid neoplasms proposed by the International Lymphoma Study Group. Blood 1994;84; 1361-92. 6. Hastrup N, Hamilton-Dutoit S, Ralfkiaer E, Pallesen G. Peripheral T-cell lymphomas: an evaluation of reproducibility of the updated Kiel classification. Histopathology 1991;18:99105. 7. Rüdiger T, Weisenburger DD, Anderson JR, Armitage JO, Diebold J, MacLennan KA, et al. for the Non-Hodgkin’s Lymphoma Classification Project. Peripheral T-cell lymphoma (excluding anaplastic large-cell lymphoma): results from the Non-Hodgkin’s Lymphoma Classification Project. Ann Oncol 2002;13:140-9. 8. Geissinger E, Odenwald T, Lee S-S, et al. Nodal peripheral Tcell lymphomas, and, in particular, their lymphoepithelioid (Lennert's) variant are often derived from CD8+ cytotoxic Tcells. Virchows Arch 2004;445:334-43. 9. Geissinger E, Bonzheim I, Krenacs L, et al. Identification of the tumor cells in peripheral T-cell lymphomas by combined polymerase chain reaction-based T-cell receptor ‚ spectrotyping and immunohistochemical detection with T-cell receptor ‚ chain variable region segment-specific antibodies. J Mol Diagn 2005;7:455-64. 10. Went P, Agostinelli C, Gallamini A, et al. Marker expression in peripheral T-cell lymphoma: a proposed clinical-pathologic prognostic score. J Clin Oncol 2006; 24:2472-9. 11. Geissinger E, Bonzheim I, Krenacs, et al. Nodal peripheral Tcell lymphomas correspond to distinct mature T-cell populations. J Pathol 2006;210:172-80. 12. Dogan A, Attygalle AD, Kyriakou C. Angioimmunoblastic Tcell lymphoma. Brit J Haematol 2003;121:681-91. 13. Dupuis J, Boye K, Martin N, at al. Expression of CXCL13 by neoplastic cells in angioimmunoblastic T-cell lymphoma (AITL). Am J Surg Pathol 2006;30:490-4. 14. Kim CH, Lim HW, Kim JR, Rott L, Hillsamer P, Butcher EC. Unique gene expression program of huma germinal center T helper cells. Blood 2004;104:1952-60. 15. De Leval L, Rickman DS, Thielen C, et al. The gene expression profile of nodal peripheral T-cell lymphoma demonstrates a molecular link between angioimmunoblastic T-cell lymphoma (AITL) and follicular helper T cells (TFH). Blood 2007, prepublished online February 6. 16. Jaffe ES. Anaplastic large cell lymphoma: the shifting sands of diagnostic hematopathology. Mod Pathol 2001;14:219-28. 17. Benharroch T, Meguerian-Bedoyan Z, Lamant L, et al. ALKpositive lymphoma: a single disease with a broad spectrum of morphology. Blood 1998;91:2076-84. 18. Traverse-Glehen A, Pittaluga S, Gaulard P, et al. Mediastinal grey zone lymphoma: the missing link between classic Hodgkin's lymphoma and mediastinal large cell lymphoma. Am J Surg Pathol 2005;29:1411-21. 19. Bonzheim I, Geissinger E, Roth S, et al. Anaplastic large cell lymphomas lack the expression of T-cell receptor molecules or molecules of proximal T-cell receptor signaling. Blood 2004;104:3358-60. 20. Stein H, Foss H-D, Dürkop H, et al. CD30+ anaplastic large cell lymphoma: a review of its histopathologic, genetic, and clinical features. Blood 2000;96:3681-95. 21. Lim M, Elenitoba-Johnson KSJ. Mass spectrometry-based proteomic studies of human anaplastic large cell lymphoma. Molecular & Cellular Proteomics 2006;5:1787-98. 22. Ballester B, Ramuz O, Gisselbrecht C, et al. Gene expression profiling identifies molecular subgroups among nodal peripheral T-cell lymphomas. Oncogene 2006;25:1560-70. 23. Piccaluga PP, Agostinelli C, Califano A, et al. Gene expression analysis of peripheral T cell lymphoma, unspecified, reveals distinct profiles and new potential therapeutic targets. J Clin Invest 2007, published online February 17, 2007. 24. Streubel B, Vinatzer U, Willheim M, Raderer M, Chott A. Novel t(5;9)(q33;q22) fuses ITK to SYK in unspecified peripheral T-cell lymphoma. Leukemia 2006;20:313-8. 25. Cheung MMC, Chan JKC, Lau WH, et al. Primary nonHodgkin's lymphoma of the nose and nasopharynx: clinical features, tumor immunophenotype, and treatment outcome in 113 patients. J Clin Oncol 1998;16:70-7. 26. Nava VE, Jaffe ES. The pathology of NK-cell lymphomas and leukemias. Adv Anat Pathol 2005; 12:27-34. 27. Krenacs L, Smyth MJ, Bagdi E, et al. The serine protease granzyme M is preferentially expressed in NK-cell, gamma delta T-cell, and intestinal T-cell lymphomas: evidence of origin of lymphocytes involved in innate immunity. Blood 2003; 101:3590-3. 28. Jaffe ES. Pathobiology of peripheral T-cell lymphomas. Hematology Am Soc Hematol Educ Program 2006;317-22. 29. Haedicke W, Ho FCS, Chott A, et al. Expression of CD94/NKG2A and killer immunoglobulin-like receptors in NK cells and a subset of extranodal cytotoxic T-cell lymphomas. Blood 2000;95:3628-30. 30. Lin CW, Chen YH, Chuang YC, Liu TY, Hsu SM. CD94 transcripts imply a better prognosis in nasal-type extranodal NK/T-cell lymphoma. Blood 2003;102:2623-31. 31. Dictor M, Cervin A, Kalm O, Rambech E. Sinonasal T-cell lymphoma in the differential diagnosis of lethal midline granuloma using in situ hybridization for Epstein-Barr virus RNA. Mod Pathol 1996;9:7-14. 32. Nakashima Y, Tagawa H, Suzuki R, et al. Genome-wide arraybased comparative genomic hybridization of natural killer cell lymphoma/leukemia: different genomic alteration patterns of aggressive NK-cell leukemia and extranodal NK/T-cell lymphoma, nasal type. Genes Chromosomes Cancer 2005;44:24755. 33. Chott A, Haedicke W, Mosberger I, et al. Most CD56+ intestinal lymphomas are CD8+CD5- T-cell lymphomas of monomorphic small to medium size histology. Am J Pathol 1998;153:1483-90. 34. Chott A, Vesely M, Simonitsch I, et al. Classification of intestinal T-cell neoplasms and their differential diagnosis. Am J Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 81 | 12th Congress of the European Hematology Association Clin Pathol 1999;111:S68-S74. 35. deLeeuw RJ, Zettl A, Klinker E, et al. Whole genome and HLA genotyping of enteropathy-type T-cell lymphoma reveals two distinct lymphoma subtypes. Gastroenterology 2007, in press. 36. Zettl A. Rüdiger T, Müller-Hermelink K-H. Enteropathy type T-cell lymphomas: pathology and pathogenesis. Pathologe 2007;28:59-64. 37. Zettl A, Ott G, Makulik A, et al. Chromosomal gains at 9q characterize enteropathy-type T-cell lymphoma. Am J Pathol 2002;161:1635-45. 38. Bagdi E, Diss TC, Munson P, Isaacson PG. Mucosal intraepithelial lymphocytes in enteropathy-associated T-cell lymphoma, ulcerative jejunitis, and refractory celiac disease constitute a neoplastic population. Blood 1999;94:260-4. 39. Cellier C, Delabesse E, Helmer C, et al. Refractory sprue, coeliac disease, and enteropathy-associated T-cell lymphoma. Lancet 2000;356:203-8. 40. Daum S, Cellier C, Mulder CJJ. Refractory coeliac disease. Best Pract Res Clin Gastroenterol 2005;19:313-21. 41. Verkarre V, Romana SP, Cellier C, et al. Recurrent partial trisomy 1q22-q44 in clonal intraepithelial lymphocytes in refractory celiac sprue. Gastroenterology 2003;125:40-6. 42. Cooke CB, Krenacs L, Stetler-Stevenson M, et al. Hepatosplenic T-cell lymphoma: a distinct clinicopathological entity of cytotoxic gamma delta T-cell origin. Blood 1996;88:426574. 43. Belhadj K, Reyes F, Farcet J-P, et al. Hepatosplenic γδ T-cell lymphoma is a rare clinicopathological entity with poor outcome: report on a series of 21 patients. Blood 2003;102:42619. 44. Alonsozana ELC, Stamberg J, Kumar D, et al. Isochromosome 7q: the primary cytogenetic abnormality in hepatosplenic gd T-cell lymphoma. Leukemia 1997;11:1367-72. 45. Willemze R, Jaffe ES, Burg G, et al. WHO-EORTC classification for cutaneous lymphomas. Blood 2005;105:3768-85. 46. Massone C, Chott A, Metze D, et al. Subcutaneous, blastic natural killer (NK), NK/T-cell, and other cytotxic lymphomas of the skin. Am J Surg Pathol 2004;28:719-35. | 82 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) What’s New in T-cell non-Hodgkin’s Lymphomas? Current treatment of T-cell lymphomas: are we making any progress? A A. Delmer Hematology Department, Hôpital Robert Debré, Avenue du Général Koenig, Reims, France Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:83-88 B S T R A C T Peripheral T-cell lymphomas represent a minority of the non-Hodgkin’s lymphomas and include several heterogeneous entities. The more frequent subtypes, at least in Western countries are peripheral T cell lymphoma, unspecified, anaplastic large cell lymphoma and angioimmunoblastic T cell lymphoma. The prognosis of peripheral T/NK neoplasms is still poor, with 5-year survival less than 30% in most cases. There is currently no consensus about the optimal therapy of these uncommon disorders mainly with regard to the standard initial regimen, whether all entities should be treated similarly, and the place of autologous or allogeneic stem cell transplantation. Progress is likely to come from the identification of novel agents active in relapsed patients which will be combined with or replace usual cytotoxic agents. Collaborative efforts to set up large multicentric trials aimed at efficiently examining these are also needed. ature T-cell and NK-cell lymphomas account for only 12% of all non-Hodgkin’s lymphomas with an incidence of 1.79 per 100,000 person-years in US during the period 19922001 (compared to 26.13 for the whole Bcell malignancies).1 They encompass several well identified entities listed in the WHO classification according to their predominant clinical feature, leukemic, cutaneous, other extranodal and nodal.2 Apart from cutaneous T-cell lymphomas (CTCL), the most frequent subtypes of peripheral T-cell lymphoma (PTCL) are peripheral T-cell lymphoma, unspecified (PTCLU), angioimmunoblastic T-cell lymphoma (AILT) and anaplastic large cell lymphoma (ALCL). EBV-associated extranodal NK/T-cell lymphoma, nasal and nasal-type, is rare in Western countries and is more prevalent in Asia and in South and Central America whereas adult T-cell leukemia/lymphoma (ATLL) is observed in countries where HTLV-1 is endemic. Patients with nodal PTCL commonly present with advanced stage disease and unfavourable clinical features, such as B symptoms, elevated LDH levels, bone marrow involvement and poor performance status. Consequently, more than a half of these patients have an unfavorable IPI (International Prognostic Index) score at diagnosis.3 Although the different subtypes of noncutaneous T-cell lymphomas may have different origins and mechanisms of M growth, from a therapeutic point of view they are currently considered as one group. With the exception of anaplastic lymphoma kinase (ALK)-positive ALCLs, which share a similar or even better outcome than diffuse large B-cell lymphomas (DLBCL),4,5 PTCLs have a worse prognosis due to both a lower response rate to anthracycline and cyclophosphamide containing regimens and a higher incidence of relapse, mainly in patients with the highest IPI scores.6 Among the 1883 patients with aggressive lymphoma and reviewed histologic data enrolled in the GELA LNH-87 trials between 1987 and 1993, 288 patients (15%) had a T-cell lymphoma including 60 patients with ALCL. Sixty-five percent of patients with a non ALCL T-cell lymphoma displayed 2 or 3 unfavorable parameters of the age-adjusted IPI (aa-IPI). Most of these patients received an intensified CHOP regimen (ACVBP). In this cohort of patients with T-cell lymphoma, the complete response (CR) rate after chemotherapy was significantly lower than in patients with DLBCL: 58% vs 63% for patients with aa-IPI 2, 35% vs 52% for patients with aa-IPI 3, and 42% vs 56% for patients with aa-IPI score 2 or 3. The 5-year overall survival was also significantly lower in patients with T-cell lymphoma as compared with outcome of patients with DLBCL: 35% for the entire cohort of non ALCL PTCL vs 52% for DLBCL, 36% vs 53% and 23% vs 35% for Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 83 | 12th Congress of the European Hematology Association Table 1. Classification of mature T-cell and NK-cell lymphomas.2 WHO histological classification of mature T-cell and NK-cell neoplasms Leukemic or disseminated T-cell prolymphocytic leukemia T-cell granular lymphocytic leukemia Aggressive NK-cell leukaemia Adult T-cell lymphoma leukemia Other extranodal Extranodal NK/T-cell lymphoma, nasal type Enteropathy-type T-cell lymphoma Hepatosplenic T-cell lymphoma Subcutaneous panniculitis-like T-cell lymphoma Cutaneous Blastic NK-cell lymphoma Mycosis fungoides/Sezary syndrome Primary cutaneous anaplastic large cell lymphoma Lymphomatoid papulosis Nodal Peripheral T-cell lymphoma, unspecified (PTL, unspecified) Angioimmunoblastic T-cell lymphoma (AIL-T) Anaplastic large cell lymphoma (ALCL) patients with aa-IPI 2 and aa-IPI 3 respectively.6 Very similar results were observed in the other large series of PTCLs with an overall survival repeatedly close to 30-35% at 3 to 5 years.7-9 These poor results emphasize the need for more efficient strategies in patients with T-cell lymphoma to improve both response rate and duration of response, whereas patients with DLCBL were shown to benefit from the combination of chemotherapy and immunotherapy with rituximab. Prognostic factors Among nodal PTCLs, histologic subtype does not appear to have prognostic relevance, except for ALKpositive ALCL which is significantly associated with a better outcome, and the behavior of patients is similar whether they have PTCLU, AILT or ALK-negative ALCL.5,6,10 Several studies have confirmed the usefulness of the IPI in some of the specific PTCL subtypes such as ALCL (ALK-positive or -negative) or PTCLU.5,6,10,11 Based strictly on the IPI the 5-year survival for patients with any T-cell lymphoma was 74%, 49%, 21%, and 6% for the low, low-intermediate, highintermediate, and high risk groups respectively.7 However, IPI was not predictive of survival in a recent large series of AILT.12 The applicability of IPI to NK/T-cell lymphomas has led to variable results while it has not been evaluated in other rare subtypes of extranodal T-cell lymphoma. A new prognostic model, PIT, specifically designed for PTCLU, was recently proposed by Gallamini et al. from a large cohort of 385 patients.11 This model includes most of the IPI parameters (age, performance status and LDH) in addition to bone marrow involvement instead of stage. The 5-year survival of PTCLU patients ranges from 62% (0 factor) to 18% (3 or 4 factors) and about half the patients fall into the highrisk categories with a 5-year survival which does not exceed 30%. In a multivariate analysis of 475 cases of PTCLU and AILT, the international PTCL project has found age, performance status and platelet count (150 K vs > 150 K) significantly correlated with the 5year survival that ranged from 42% (0 factor) to 12% (3 factors). Comparison with the standard IPI and the PIT index on this population demonstrated that in all 3 indices, the failure free survival and overall survival were very poor for all patients except in those with 0 or 0/1 risk factors.13 A high expression of proliferation-associated antigen Ki-67 (≥80%) was found predictive of poor survival in PTCLU and was therefore integrated along with age, performance status and LDH in a prognostic score where patients with 3 or 4 factors (representing only 12% of the cohort) had a median survival of 6 months.14 The clinical heterogeneity of PTCLUs, which represent subgroup and in most cases express a CD4+CD8– phenotype, may be explained by variable chemokine receptors expression. In one study, two groups of PTCLU were identified, one expressing either Th2 (ST2(L)) or Th1 (CCR5, CXCR3) markers and another negative for all these markers. Patients belonging to the former group considered as functional had a better outcome than those in the latter group.15 The heterogeneity of PTCLUs with regard to expression of Th1 (CXCR3) and Th2 (CCR4) markers was confirmed in a second study in which patients with CCR4 expression displayed a poorer outcome.16 CCR4 expression was also observed in most cases (88%) of ATLL17 and a monoclonal antibody directed against CCR4 in this disease is currently under investigation. The expression of cytotoxic molecules TIA-1 and granzyme B in PTCLU has been correlated with a higher IPI, a lower CR rate (30% vs 63%), and a worse overall survival.18 Gene expression studies have also emphasized the heterogeneity of PTCLU and three molecular subgroups were identified in a series of 32 cases. One subgroup had a gene expression signature including genes known to be associated with poor outcome in other tumors, such as CCND2. A second subgroup was characterized by the overexpression of genes involved in T-cell activation and apoptosis, including | 84 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 NFKB1 and BCL-2. A third subgroup was mainly defined by overexpression of genes involved in the IFN/JAK/STAT pathway.19 The small number of cases in this series precluded valuable clinical correlations but there was a trend for an inferior survival in patients belonging to the first group. The expression of NFkB genes was investigated in a group of 62 PTCL (PTCLU 39, AILT 7, ALCL 7, others 9). One third of cases showed a reduced expression of NF-κB genes while other cases showed a high expression of these genes. Both patterns were observed independently of histologic subtype (except for ALCL which was characterized by a reduced expression of NF-κB genes). Signature with reduced expression of NF-κB genes was associated with a shorter survival.20 Other studies have shown deregulated expression of genes involved in apoptosis, proliferation, cell adhesion and matrix remodeling, as compared with normal T cells. Furthermore, usually PTCLUs aberrantly express the tyrosine-kinase receptor PDGFRα and cultured PTCL cells were shown to be sensitive to imatinib as well as to a novel inhibitor of histone deacetylase.21 Further confirmation of these findings may help identify new potential targets for therapy. First line treatment There is no consensus about the optimal first line and subsequent treatment for PTCL but there is general agreement on the unsatisfying results observed with conventional therapeutic strategies. Whether all PTCL subtypes should be managed similarly or not may be a matter of debate. For the time being, there is no data to support the concept that nodal PTCLs and (PTCLU, AITL and ALK-negative ALCL) should be offered different strategies since with current cytotoxic regimens their behavior is similar. This also applies to the rare categories with an even poorer prognosis such as hepatosplenic γδ Tcell lymphoma (HSTCL) or enteropathy associated T-cell lymphoma (EATCL), unless effective innovative strategies become available. One exception is extranodal NK/T cell lymphoma, nasal-type, for which radiotherapy appears to be the key treatment modality in localized stages. More favorable outcomes were observed in treatment regimens that incorporate radiotherapy.22, 23 Over the years, PTCLs have usually been treated with CHOP or CHOP-like regimens as the mainstay of therapy, as were advanced stage DLBCL before the era of rituximab. With front-line anthracyclinebased combination chemotherapy, approximately 50% of patients with PTCL achieve a complete remission and reported 5-year survival rates range from 25 to 45%.6-9 Very few studies, generally with a low number of patients and including patients with ALCL, have shown an improvement in response rates and overall survival when a more dose-intensive induction treatment was used.24 The GELA has evaluated intensified alternative regimens in both young and elderly patients with T-cell lymphoma, using intensified induction therapy with etoposide and high-dose cytarabine in 89 patients aged less than 60 years and ESHAP regimen in combination with 13-cis-retinoic acid in 77 patients over 60 years. The response rate, event-free survival and overall survival in each group were not superior to those usually achieved with CHOP or CHOP-like regimen.25,26 A randomized study comparing alternating cycles of VIP (etoposide, ifosfamide, platine) and ABVD regimens to CHOP in 88 PTCL patients did not show any improvement over CHOP.27 In a trial of the Nordic Lymphoma Group, where patients were randomized to either CHOP or MACOP-B, patients with PTCL, although still displaying a poorer prognosis than DLBCL patients, had a slight survival advantage from the more doseintense MACOP-B chemotherapy arm.28 Two different randomized studies performed by the German High-Grade Non-Hodgkin's Lymphoma Study Group indicated a survival benefit of a timeintensified CHOP regimen (CHOP14) in young patients as well as in patients aged over 60 years with a diagnosis of aggressive lymphoma of B- or T-cell origin.29,30 Although these studies have been published without a specific analysis of patients with Tcell lymphoma, numerous patients with PTCL are now receiving CHOP14 as front line regimen. Autologous transplantation The role of autologous stem cell transplantation (ASCT) in PTCLs, mainly performed early in first CR as part of up-front therapy, still remains controversial. High dose therapy followed by ASCT has for decades been the most widely adopted approach for patients under 60-65 years with relapsed aggressive lymphoma (either B or T-cell derived) and chemosensitive disease. Several series have reported the outcomes of patients with relapsed T-cell NHL after ASCT. They mainly included patients with PTCLU or ALCL and the 3-year survival rates ranged from 36% to 58%.31,32 Patients with ALCL (vs non ALCL) had a better outcome with a 3-year survival rate of 79% (vs 44%). In one retrospective study, the outcome of 36 patients with relapsed or primary refractory PTCL and 97 patients with relapsed DLBCL were compared. There was no difference in 3-year survival between patients with PTCL or DLBCL (48% vs 53%), suggesting that high-dose therapy may overcome the adverse effect of T-cell pheno- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 85 | 12th Congress of the European Hematology Association type. However, patients with PTCLU had a trend for poorer survival.33 Patients who do not achieve a complete response after initial chemotherapy may also benefit from ASCT.34 Some studies of high-dose chemotherapy and ASCT performed in first CR are now available for PTCL patients. However, some of these studies have included a significant number of patients with ALCL, therefore leading to an overestimate of its potential benefit. The results of the Spanish group have been recently updated. In a cohort of 74 patients including 23 patients (31%) with ALCL (ALK status unavailable for most of them), the 5-year survival and progression free survival (PFS) were 68% and 63% respectively with a median follow-up of 63 months.35 Two prospective phase II studies investigating the role of high-dose sequential chemotherapy, followed by ASCT in 62 patients with advanced stage PTCLs have shown that 46 patients (74%) completed the whole programme, whereas 16 patients did not undergo ASCT, mainly because of disease progression. With a median follow-up of 76 months, the estimated 12-year overall, disease-free and event-free survival were 34, 55 and 30% respectively. Results were significantly better in the 19 patients (30%) with ALK-positive ALCL.36 A German study has evaluated a strategy combining 4 to 6 cycles of CHOP regimen followed by one course of Dexa-BEAM, then high dose therapy and ASCT. In 38% of the 65 evaluable patients, progressive disease occurred prior to transplantation and among the remaining patients, 27% relapsed at a median follow-up of 10 months post-transplant.37 The Nordic Lymphoma Group has tested a dose-intensified induction schedule (6 courses of CHOEP14) followed by autologous transplant in first remission. Among the 77 patients who completed induction regimen, 66 (88%) are in CR or partial response. A total of 58 patients (75%) have received ASCT and 9 out of 39 patients with a one year follow-up after transplant have relapsed. Therefore, 25% could not receive the program because of early progression and an additional 25% will relapse after ASCT.38 In these studies, a significant number of patients were not able to reach ASCT because of early progression. This underlines the need for more efficient induction treatments. Furthermore, in a retrospective analysis of all patients enrolled in the French GELA LNH87 and LNH93 programs and who were transplanted in first CR, after multivariate analysis T-cell phenotype (excluding ALCL subtype) still remained an adverse prognostic parameter significantly associated with a poorer outcome after transplantation.39 Allogeneic transplantation Data of the results from allogeneic transplantation in patients with T-cell lymphoma is scarce. Apart from general observations, some smaller series have been published. A series of 8 patients with Sezary syndrome or tumor-stage mycosis fungoides showed that all patients achieved a CR after transplantation. With a median follow-up of 56 months, 6 patients remained alive and well.40 Another series reported 11 patients with various T-cell lymphomas who had been allografted with a reduced intensity conditioning after salvage therapy including alemtuzumab and the ICE regimen. Six patients were alive and free of disease at a median follow-up of 7 months.41 The largest series has been reported by Corradini et al. and recently updated.42,43 A total of 26 patients were allografted for relapsed T-cell lymphoma after reduced intensity conditioning with thiotepa, fludarabine, and cyclophosphamide. The estimated 5year overall survival and progression free survival were 61% and 51% respectively. This study showed that long-term disease control can be achieved by allogeneic transplantation via a graft versus T-cell lymphoma effect. Three out of 8 patients with relapsed disease after transplantation responded to donor lymphocyte infusion (DLI). These results suggest that allogeneic transplantation with reduced intensity conditioning may be a suitable option for young patients with relapsed disease and an available donor. It could also be evaluated as up-front strategy in patients with poor-risk T-cell lymphoma, possibly following autologous transplantation. New agents Since most patients will fail to first line therapy, new treatment modalities should be explored. It is likely that significant progress will not be made from the alternative use of classic cytotoxic agents. Some agents have demonstrated significant activity in cutaneous T-cell lymphoma but activity in CTCL does not mean they would also be effective in nodal or other extranodal T-cell lymphomas. Purine analogs, pentostatin, fludarabine and cladribine, have all been reported to have some activity in CTCL and PTCLs with response rates ranging from 20 to 70%. Response rates appeared higher with pentostatin than with other compounds.44 Fludarabine was used in combination with cyclophosphamide, doxorubicin and alemtuzumab in patients with various subtypes of PTCLs (excluding ALK-positive ALCL and CTCL) and led to a 73% CR rate in previously untreated patients.45 The response rate to treatment with the pyrimidine analog gemcitabine in patients with relapsed Tcell lymphoma was around 60-70%46 but this agent has mostly been investigated in CTCL. | 86 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Pralatrexate is a derivative of methotrexate with a higher affinity to the reduced folate carrier. Among the 16 evaluable patients with relapsed PTCL who completed at least 2 courses, the response rate was impressive with 10 patients achieving a major response including 9 CR. Some of these were of a long duration.47 Denileukin diftitox, a fusion protein combining the receptor-binding domain of interleukin-2 and diphtheria toxin, is already approved for the treatment of refractory CTCL. In 25 evaluable patients with non cutaneous T-cell lymphoma, the response rate was 48% with 20% CR and responses were observed CD25-positive and CD25-negative lymphomas.48 Combination of this agent with CHOP regimen appeared feasible.49 Monoclonal antibody alemtuzumab directed against CD52 antigen has been evaluated in a short series of 14 patients with heavily pretreated nodal Tcell lymphoma. Alemtuzumab was programed to be administered intravenously three times a week for 12 weeks. The response rate was quite high, with 3 patients achieving a CR and 2 patients a partial response. However, in these poor prognosis patients there was considerable infectious toxicity.50 Using a lower dosage and subcutaneous route, a 60% response rate was observed in a series of 10 patients with CTCL and nodal PTCL.51 Experience with the combination of alemtuzumab and chemotherapy, mainly CHOP and CHOP-like regimens, is still limited.45,52 Alemtuzumab was usually administered for one or 2 days along with chemotherapy either by IV or subcutaneous route. Preliminary results showed good tolerability and feasibility for these combinations. However, a recent immunochemistry study has evaluated CD52 expression in various hematological malignancies and only 35% (7/20) of PTCLU and 40% (2/5) of AITL cases were found to express CD52 whereas this antigen is highly expressed in normal T-cells.53 These results need to be confirmed and suggest that patients should be assessed for CD52 expression before being offered a treatment with alemtuzumab. Histone deacetylase (HDAC) inhibitor depsipeptide has been evaluated in a series of 19 patients with PTCL leading to a 26% response rate.54 Vorinostat (suberoylanilide hydroxamic acid, SAHA), another HDAC inhibitor, has only been evaluated so far only in refractory CTCL. A partial response was observed in 8 out of 33 evaluable patients with a median duration of response of 15 weeks.55 Conclusions Progress in the treatment of T-cell lymphomas remains a challenging issue due to their rarity, unsatisfactory response to current chemotherapy regimens and, for the time being, the lack of novel agents likely to be incorporated into first line treatment. With a few exceptions, treatment modalities should not depend on histologic subtype, and nodal PTCLs should be treated similarly unless otherwise indicated by ongoing gene profiling or other biological studies. International collaborative efforts are essential to make advances in the treatment of T-cell lymphomas and already several initiatives are focusing on the evaluation of alemtuzumab in combination with chemotherapy, and of allogeneic stem cell transplantation performed early as part of first-line treatment. References 1. Morton LM, Wang SS, Devesa SS, et al. Lymphoma incidence patterns by WHO subtype in the United States 1992-2001. Blood 2006;107:265-76. 2. Jaffe ES, Harris NL, Stein H, Vardiman JW (eds): World Health Organization classification of tumours. Pathology and Genetics of Tumours of haematopoietic and lymphoid tissues. IARC Press: Lyon 2001 3. Rodiger T, Weisenburger DD, Anderson JR, et al. Peripheral Tcell lymphoma (excluding anaplastic large-cell lymphoma): results from the Non-Hodgkin's Lymphoma Classification Project. Ann Oncol 2002;13:140-9. 4. Tilly H, Gaulard P, Lepage E, et al. Primary anaplastic large-cell lymphoma in adults: clinical presentation, immunophenotype, and outcome. Blood 1997;90:3727-34. 5. ten Berge RL, de Bruin PC, Oudejans JJ, et al. ALK-negative anaplastic large-cell lymphoma demonstrates similar poor prognosis to peripheral T-cell lymphoma, unspecified. Histopathology 2003;43:462-9. 6. Gisselbrecht C, Gaulard Ph, Lepage E, et al. Prognostic significance of T-cell phenotype in aggressive non-Hodgkin’s lymphomas. Groupe d’Etudes des Lymphomes de l’Adulte (GELA). Blood 1998;92:76-82. 7. Lopez-Guillermo A, Cid J, Salar A et al. Peripheral T-cell lymphomas: initial features, natural history and prognostic factors in a series of 174 patients diagnosed according to the R.E.A.L. Classification. Ann Oncol 1998;9:849-55. 8. Melnyk A, Rodriguez A, Pugh WC, Cabannillas F. Evaluation of the Revised European-American Lymphoma classification confirms the clinical relevance of immunophenotype in 560 cases of aggressive non-Hodgkin’s lymphoma. Blood 1997;89: 4514-20. 9. Escalon MP, Liu NS, Yang Y et al. Prognostic factors and treatment of patients with T-cell Non-Hodgkin Lymphoma. Cancer 2005;103:2091-8. 10. Sonnen R, Schmidt WP, Muller-Hermelink HK and Schmitz N. The International Prognostic Index determines the outcome of patients with nodal mature T-cell lymphomas. Br J Haematol 2005;129:366-372. 11. Gallamini A, Stelitano C, Calvi R, et al. Peripheral T-cell lymphoma unspecified (PTCL-U): a new prognostic model from a retrospective multicentric clinical study. Blood 2004;103:24749. 12. Mourad N, Mounier N, Brière J, et al. Angioimmunoblastic TCell Lymphoma: a clinicopathologic study of 158 Patients treated in GELA (Groupe d'Etude des Lymphomes de l'Adulte) trials [abstract]. Blood 2006;108:121a. 13. Vose JM, the International PTCL Project. International peripheral T-cell lymphoma (PTCL) clinical and pathological review project: poor outcome by prognostic indices and lack of efficacy with anthracyclines [abstract]. Blood 2005;106:#811. 14. Went P, Agostinelli C, Gallamini A, et al. Marker expression in peripheral T-cell lymphoma: a proposed clinical-pathologic prognostic score. J Clin Oncol 2006;24:1-8. 15. Tsuchiya T, Ohshima K, Karube K, et al. Th1, Th2, and activated T-cell marker and clinical prognosis in peripheral T-cell lymphoma, unspecified: comparison with AILD, ALCL, lymphoblastic lymphoma, and ATLL. Blood. 2004;103:236- 241. 16. Ishida T, Inagaki H, Utsunomiya A, et al. CXC chemokine receptor 3 and CC chemokine receptor 4 expression in T-cell Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 87 | 12th Congress of the European Hematology Association 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. and NK-cell lymphomas with special reference to clinicopathological significance for peripheral T-cell lymphoma, unspecified. Clin Cancer Res. 2004;10:5494-500. Ishida T, Utsunomiya A, Iida S, et al. Clinical significance of CCR4 expression in adult T-cell leukemia/lymphoma (ATLL): its close association with skin involvement and unfavorable outcome. Clin Cancer Res 2003;9:3625–34. Asano N, Suzuki R, Kagami Y, et al. Clinicopathologic and prognostic significance of cytotoxic molecule expression in nodal peripheral T-cell lymphoma, unspecified. Am J Surg Pathol 2005;29:1284-93. Ballester B, Ramuz O, Gisselbrecht C, et al. Gene expres¬sion profiling identifies molecular subgroups among nodal peripheral T-cell lymphomas. Oncogene 2006;25:1560-70. Martinez-Delgado B, Cuadros M, Honrado E, et al. Differential expression of NF-kB pathway genes among peripheral T-cell lymphomas. Leukemia 2005;19:2254-2263. Piccaluga PP, Agostinelli C, Califano A, et al. Gene expression analysis of peripheral T cell lymphoma, unspecified, reveals distinct profiles and new potential therapeutic targets. J Clin Invest 2007;117:823-34. Cheung MM, Chan JK, Lau WH, Ngan RK, Foo WW. Early stage nasal NK/T-cell lymphoma: clinical outcome, prognos¬tic factors, and the effect of treatment modality. Int J Radiat Oncol Biol Phys 2002;54:182-90. You JY, Chi KH, Yang MH, et al. Radiation therapy versus chemotherapy as initial treatment for localized nasal natural killer (NK)/T-cell lymphoma: a single institute survey in Taiwan. Ann Oncol 2004;15:618-25. Karakas T, Bergmann L, Stutte HJ et al. Peripheral T-cell lymphomas respond well to vincristine, adriamycin, cyclophosphamide, prednisone and etoposide (VACPE) and have a similar outcome as high-grade B-cell lymphomas. Leuk Lymph 1996;24:121-9. Delmer A, Mounier N, Gaulard P, et al. Intensified induction therapy with etoposide (VP16) and high-dose cytarabine (AraC) in patients aged less than 60 years with peripheral T- and NK-cell lymphoma: preliminary results of the GELA phase II study LNH98T7. Proc ASCO meeting [abstract]. J Clin Oncol 2003;22 (suppl): 591 Bouabdallah R, Delmer A, Xerri L, et al. ESHAP chemotherapy regimen and 13-cis-retinoic acid in elderly patients with untreated poor prognosis peripheral T cell lymphoma: a GELA phase II trial of feasability and efficacy [abstract]. 9th ICML, Lugano 2005, Ann Oncol 16 (suppl 5): v131. Gressin R, Peoch M, Deconinck et al. The VIP-ABVD regimen is not superior to the CHOP21 for the treatment of non epidermotropic peripheral T cell lymphoma. Final results of the LTP95 protocol of the GOELAMS [abstract]. Blood 2006; 108: 697a. Jerkeman N, Anderson H, Cavalli-Stahl E et al. CHOP versus MACOP-B in aggressive lymphoma - A Nordic Lymphoma Group randomized trial. Ann Oncol 1999;10:1079-86. Pfreundchuh M, Trumper L, Kloess M et al. Two-weekly or 3weekly CHOP chemotherapy with or without etoposide for the treatment of elderly patients with aggressive lymphomas: results of the NHL-B2 trial of the DSHNHL. Blood 2004;104:634-41. Pfreundschuh M, Trumper L, Kloess M et al. Two-weekly or 3-weekly CHOP chemotherapy with or without etoposide for the treatment of young patients with good-prognosis (normal LDH) aggressive lymphomas: results of the NHL-B1 trial of the DSHNHL. Blood 2004;104:626-33. Blystad AK, Enblad G, Kvaloy S, et al. High-dose therapy with autologous stem cell transplantation in patients with peripheral T cell lymphomas. Bone Marrow Transplant 2001;27:711-6. Rodriguez J, Munsell M, Yazji S, et al. Impact of high-dose chemotherapy on peripheral T-cell lymphomas. J Clin Oncol 2001;19:3766-70. Song KW, Mollee P, Keating A, Crump M. Autolo¬gous stem cell transplant for relapsed and refrac¬tory peripheral T-cell lymphoma: variable outcome according to pathological subtype. Br J Haematol 2003;120:978-85. Rodriguez J, Caballero MD, Gutierrez A, et al. High dose chemotherapy and autologous stem cell transplantation in patients with peripheral T-cell lymphoma not achieving complete response after induction chemotherapy: the GEL-TAMO experience. Haematologica 2003;88: 372-7. Rodrigez J, Conde E, Gutierrez A, et al. The results of consolidation with autologous stem-cell transplantation in patients with peripheral T-cell lymphoma (PTCL) in first complete remission: the Spanish Lymphoma and Autologous Transplantation Group experience. Ann Oncol 2007 Jan 17; [Epub ahead of print]. Corradini P, Tarella C, Zallio F, et al. Long-term follow-up of 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. patients with peripheral T-cell lymphomas treated up-front with high-dose chemotherapy followed by autologous stem cell transplantation. Leukemia 2006;20:1533-8. Reimer P, Ruediger T, Schertlin T et al. Autologous stem cell transplantation as first-line therapy in peripheral T-cell lymphomas. A prospective multicenter study [abstract]. Blood 2005;106:#2074. d'Amore F, Relander T, Lauritzsen G, et al. Dose-Dense Induction Followed by Autologous Stem Cell Transplant (ASCT) as 1st Line Treatment in Peripheral T-Cell Lymphomas (PTCL) – A Phase II Study of the Nordic Lymphoma Group [Abstract]. Blood 2006;108:#401 Mounier N, Gisselbrecht C, Briere J et al. Prognostic factors in patients with aggressive non-Hodgkin's lymphoma treated by front-line autotransplantation after complete remission: a cohort study by the Groupe d'Etude des Lymphomes de l'Adulte. J Clin Oncol 2004;22:2826-34. Molina A, Zain J, Arber DA, et al. Durable clinical, cytogenetic, and molecular remissions after allogeneic hematopoietic cell transplantation for refractory Sezary syndrome and mycosis fungoides. J Clin Oncol 2005; 23: 6163-71. Wulf GG, Hasenkamp J, Jung W, et al. Reduced intensity conditioning and allogeneic stem cell transplantation after salvage therapy integrating alemtuzumab for patients with relapsed peripheral T-cell non-Hodgkin's lymphoma. Bone Marrow Transplant 2005;36:271-3. Corradini P, Dodero A, Zallio F, et al. Graft-versus-lymphoma effect in relapsed peripheral T-cell non-Hodgkin's lymphomas after reduced-intensity conditioning followed by allogeneic transplantation of hematopoietic cells. J Clin Oncol 2004;22: 2172-6. Corradini P, Dodero A, Bregni M, et al. Reduced-intensity conditioning followed by allogeneic transplantation (allo-SCT) is an effective salvage treatment for peripheral T-cell nonHodgkin's lymphoma (PTCL) [abstract]. Blood 2005;106: 328a Kurzrock R, Ravandi F. Purine analogues in advanced T-cell lymphoid malignancies. Semin Hematol. 2006;43(2 Suppl 2):S27-34. Weidmann E, Hess G, Krause SW, et al. A phase II immunochemotherapy study with alemtuzumab, fludarabine, cyclophosphamide, and doxorubicin (Campath-FCD) in peripheral T-cell lymphomas[abstract]. Blood 2006;108:769a. Sallah S, Wan JY, Nguyen NP. Treatment of refractory T-cell malignancies using gemcitabine. Br J Haematol 2001;113:1857. O'Connor OA, P.A. Hamlin PA, Gerecitano J et al. Pralatrexate (PDX) produces durable complete remissions in Patients with chemotherapy resistant precursor and peripheral T-Cell lymphomas: results of the MSKCC Phase I/II Experience [abstract]. Blood 2006;108:122a. Dang NH, Pro B, Hagemeister FB, et al. Phase II trial of denileukin diftitox for relapsed/refractory T-cell non-Hodgkin lymphoma. Br J Haematol 2007;136:439-47. Foss FM, Sjak-Shie N, Goy A, et al. Denileukin Diftitox (Ontak®) with CHOP chemotherapy in patients with newlydiagnosed aggressive T-cell lymphomas, the CONCEPT Trial: Interim Analysis [abstract]. Blood 2006;108:696a. Enblad G, Hagberg H, Erlanson M, et al. A pilot study of alemtuzumab (anti-CD52 monoclonal antibody) therapy for patients with relapsed or chemotherapy-refractory peripheral T-cell lymphomas. Blood 2004;103:2920-4. Zinzani PL, Alinari L, Tani M et al. Preliminary observations of a phase II study of reduced-dose alemtuzumab treatment in patients with pretreated T-cell lymphoma. Haematologica 2005; 90:702-3. Gallamini A, Zaja F, Gargantini L et al. CHOP chemotherapy plus Campath-1H as first-line treatment in peripheral T-cell lymphoma (PTCL) [abstract]. Blood 2005;106:#3345. Rodig SJ, Abramson JS, Pinkus GS, et al. Heterogeneous CD52 expression among hematologic neoplasms: implications for the use of alemtuzumab (CAMPATH-1H). Clin Cancer Res 2006; 12:7174-9. Piekarz RL, Frye R, Turner M, et al. Responses and molecular markers in patients with peripheral T-cell lymphoma treated on a phase II trial of depsipeptide, FK228. Proc ASCO 2005;24: 3061a. Duvic M, Talpur R, Ni X, et al. Phase 2 trial of oral vorinostat (suberoylanilide hydroxamic acid, SAHA) for refractory cutaneous T-cell lymphoma (CTCL). Blood 2007;109:31-9. | 88 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) What’s New in T-cell non-Hodgkin’s Lymphomas? Novel drugs for the treatment of T-cell lymphoma O.A. O’Connor Director, Lymphoid Development and Malignancy Program Herbert Irving Comprehensive Cancer Research Center Chief, Lymphoma Services College of Physicians and Surgeons The New York Presbyterian Hospital Columbia University New York, USA Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:89-96 diagnosis of lymphoma has long been interpreted by patients and doctors alike as a lucky diagnosis. While these diseases in general are relatively more chemotherapy sensitive than many solid tumors, many sub-types of lymphoma carry a very poor prognosis. Complicating matters further is the fact that the lymphomas represent one of the most heterogenous group of malignancies known to medicine. Underneath the single title of lymphoma exist some of the fastest growing cancers known to science (Burkitt’s lymphoma, lymphoblastic lymphoma/leukemia), as well as some of the slowest (small lymphocytic lymphoma, follicular lymphoma, and marginal zone lymphoma). Within this complex set of diseases are sub-types of lymphoma that continue to pose significant therapeutic challenges. The T-cell lymphomas represent one of those sub-types of lymphoma for which there has been remarkably little progress over recent years. These diseases not only demonstrate a worse prognosis than their B-cell counterparts but are extremely rare. This means little consensus can be established because of the difficulties in finding enough patients to enroll in the appropriate clinical studies. For this reason, there is a strong need to develop only the most active drugs for these diseases, and to begin studying the most promising new drugs in combination with historically active agents. Clearly, a consensus must be found on a new upfront treatment for these diseases to offer any hope of changing their present natural history. Furthermore, identifying new agents with novel mechanisms of action offers unique opportunities to palliatively treat these lymphomas by employing agents with less cross resistance to prior lines of conventional therapy. A Epidemiology of T-cell lymphomas The etiology of non-Hodgkin’s lymphoma (NHL) remains largely unknown. It is clear, however, that since before 1950, an epidemic of lymphoma, but not other hematopoietic neoplasms, was documented in many populations, with an estimated 50% increase in the age-adjusted incidence from 1970-1990 in the U.S1-3 While recent reports suggest that the steep rise in incidence may have slowed in recent years, caution is required in interpreting them given the innumerable factors which can influence these statistics, like autoimmune deficiency syndrome (AIDs), new diagnostic techniques, and the emergence of other etiologic factors like infections.4-8 It is interesting that industrialized nations experience a higher incidence of NHL than do developing countries, with the highest incidence rate in the world being seen in the United States (US) and Canada.6 These statistics rank NHL as the sixth most common cancer and the sixth most common cause of cancer death, accounting for 4% of all cancers and 4% of cancer deaths.9 Prevalence and incidence Based on the most recent evaluation of SEER registries presented by Morton et al.9 it is estimated there were approximately 114,548 cases of lymphoid neoplasms diagnosed per year in the United States over the period from 1992-2001, including lymphoid leukemias and Hodgkin’s Disease. Approximately 87,666 (about 76%) of these cases were B-cell lymphoid neoplasms, while only about 10,042 cases were attributed to Hodgkin’s disease. T/NK-cell malignancies constituted approximately 6,228 cases per year. In general, Tcell malignancies comprise only about 1015% of lymphoid malignancies, though there is notable variability in the literature on the precise contribution.8,10-13 According to the National Cancer Institute SEER Cancer Statistics Review 1975-2002, the prevalence for all types of sub-types of Non-Hodgkin Lymphoma was 347,039 on January 1, 2002, while the 10-year prevalence estimate was 240,065.14 Unfortunately, the prevalence estimate specific to T-cell NHL was not Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 89 | 12th Congress of the European Hematology Association Table 1. Prevalence of NHL by type, 2005. Disease Total NHL Non T-cell NHL T-cell NHL Table 2. WHO T-cell lymphoma classification. 5-year 10-year 181,928 162,639 19,289 267,116 237,509 29,607 Precursor T/NK neoplasms Precursor T lymphoblastic leukemia/lymphoma Blastic NK lymphoma Peripheral T/NK neoplasms provided in this report (SEER Cancer Statistics Review, 1975-2002, National Cancer Institute. Bethesda, MD, http://seer.cancer.gov/csr/ 1975_2002/, based on November 2004 SEER data submission, posted to the SEER web site 2005). Data provided in an analysis made by the U.S. Census Bureau and the NCI’s SEER data set (SEER*Stat 6.2) using ICD codes for all T-cell lymphoma sub-types (an analysis performed by the DaVinci Oncology Specialists) provided the following prevalence estimates for NHL according to by histology, as shown in Table 1. It is clear that the overall prevalence of T-cell NHL is well below the 200,000 limit to be net to qualify for orphan drug status. Our best estimate of the 10year prevalence is approximately 30,000, more than six times below the limit. Even the most aggressive estimate possible (15% of complete NHL prevalence of 347,039), puts the prevalence at 52,056, which is still almost four times fold below the limit. Numerous published reports, as well as the prior designation of orphan status for several products in Tcell lymphoma, confirm this conclusion.5 Recently, the U.S. FDA has acknowledged the rarity of T-cell lymphomas in the United States by granting orphan drug status to at least 6 other products for T-cell lymphoma (not counting products specified for cutaneous T-cell lymphoma). These include 1S)-1-(9deaza-hypoxanthin-9-yl)-1,4-dideoxy-1,4-imino-Dribitol-hydrochloride (BioCryst Pharma-ceuticals), siplizumab (MedImmune Oncology, Inc.), suberoylanilide hydroxamic acid (Merck & Co.), AGN-30, anti-CD30 antibody (Seattle Genetics, Inc.), and pentostatin (SuperGen). Based on admittedly preliminary data, there is a reasonable expectation that pralatrexate could act similar to or better than these agents now in clinical trials. Classification of T cell lymphomas The T cell lymphomas represent a very heterogenous array of aggressive NHLs, and though rare, they typically account for less than 10% of all newly diagnosed cases of lymphoma in the US. Interestingly, these proportions of lymphoma are the opposite of those found in Far East and Caribbean, where 7080% of all NHLs are derived from T cells. According to the World Health Organization (WHO) classification schema provided in Table 2, T cell lymphomas are divided into either precursor T/NK-cell neo- Predominantly leukemic/disseminated T-cell prolymphocytic leukemia T-cell large granular lymphocytic NK/T-cell leukemia/lymphoma Adult T-cell leukemia/lymphoma Predominantly nodal Angioimmunoblastic T-cell lymphoma Anaplastic large cell lymphoma Peripheral T-cell lymphoma (Unspecified) Predominant extranodal Mycosis Fungoides (CTCL) Sezary syndrome Primary cutaneos CD30+ disorders Anaplastic large cell lymphoma Lymphomatoid papulosis Subcutaneous panniculitis T-cell NK/T-cell lymphoma-nasal Enteropathy-type intestinal lymphoma Hepatosplenic T-cell lymphoma Extranodal peripheral T/NK-cell lymphoma (unspecified) plasms or peripheral T/NK-cell neoplasms. These categories are further sub-classified into a variety of entities.15 According to this classification scheme, there are thought to be at least 15 distinct sub-types of T cell lymphoma, most of which can be broadly classified into either aggressive or indolent lymphoproliferative diseases based on their natural history. Prognosis of T-cell lymphoma is worse than B-cell lymphoma All lymphomas are derived from lymphocytes, and are classified, where possible, based according to their cell of origin. Approximately 75% of all cases of NHL are of B cell origin, while the remainder are of T-cell origin. Lymphomas of T-cell origin have been long considered to represent a worse prognosis. While it is not entirely clear why T-cell lymphomas this is the case several theories have been advanced, including the observation that patients with T cell lymphomas generally present with more high risk disease, at least based on the International Prognostic Index (IPI), at diagnosis.16 While other hypotheses revolve around the fundamental biological differences between Band T-cell lymphomas with regard to their intrinsic chemosensitivity, the IPI allows for the risk stratification of patients with all types of lymphoma, and has been applied to patients with both indolent and | 90 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 1.0 L PROBABILITY 0.8 0.6 0.4 H/I 0.2 0 0 LH/I H 24 48 72 96 120 MONTHS Lopez-Guillermo et al. Ann Oncol 1998 Figure 1. Peripheral T-cell lymphoma. Overall survival by the IPI. aggressive lymphomas. This index is based upon 5 important prognostic factors: (1) age, (2) Eastern Cooperative Oncology Group (ECOG) performance status, (3) abnormal levels of lactate dehydrogenase (LDH), and (4) number of extra nodal sites, and (5) stage. Patients are then classified according to the number of risk factors they have as: low risk (IPI 1), low intermediate risk (IPI 2), intermediate risk (3), high-intermediate risk (IPI 4), or high risk (IPI 5). All aggressive T/NK-cell lymphomas require systemic chemotherapy from the time of diagnosis, and usually at relapse. As noted above, there are select T cell subsets of disease that are considered more indolent. They may not require treatment at diagnosis, or radically different treatments, including for example: T cell prolymphocytic leukemia (T-PLL), T cell large granular lymphocytic leukemia, primary cutaneous CD30+ disorders including anaplastic large cell lymphoma (ALCL) and lymphomatoid papulosis, or mycosis fungoides (MF)/Sézary syndrome. Because of the more indolent and favorable natural history of these diseases, they are not included in this study population. In general, T/NK- cell diseases are associated with a worse prognosis compared to their B cell counterparts. Several informative clinical series of patients have reported very poor median survivals for patients with T cell neoplasms, with 5-year survival rates of less than 30% and a median survival of less than 2 years.17-19 Incredibly, the failure-free survival for patients with high or intermediate high risk disease ranges from 0 to less than 10%, with virtually no long term survivors.18-20 In one such study, the complete response (CR) rate for patients with T/NKcell lymphoma was only 43%, while nearly half of all patients were refractory to their initial up-front chemotherapy.19 A number of important studies have tried to identify the major factors that influence survival in patients with T cell lymphoma. In one multivariate analysis of 125 patients with T cell lymphoma (PTCL-NOS [PTCL not otherwise specified], anaplastic large cell lymphoma; angioimmunoblastic lymphoma), the major parameters influencing outcome were histological subtype and the IPI21. The fiveyear overall survival with all types of T cell lymphoma was only 43%, while the 5-year relapsed-free survival was 69%.18 As expected, not all T cell lymphomas behaved exactly the same. The 5-year overall survival was 61% for anaplastic large cell lymphoma (ALCL), 45% for PTCL not otherwise specified (PTCL NOS), and 28% for angioimmunoblastic lymphoma (AILD). Based strictly on the IPI (Figure 1) in one such study, the 5-year survival for patients with any T cell lymphoma was 74%, 49%, 21%, and 6% for the low, low-intermediate, high-intermediate, and high risk groups, respectively.18 These differences in survival as a function of the IPI are demonstrated in Figure 3.4.1 These data demonstrate that IPI is an important adverse prognostic factor in PTCL, and that patients with PTCL generally present with more advanced IPI than patients with B-cell lymphomas, possibly accounting for some of the adverse prognosis associated with PTCL. It is reasonably well accepted that T cell lymphomas are more challenging to treat than B-cell lymphomas althought this has never really established in any prospective randomized clinical trial. Table 3.4.2 presents some of these data based on a publication from Gisselbrecht et al.22 For example, in this study, the 5-year survival rate for patients with 1, 2 or 3 risk factors with B- versus T cell lymphoma was 63% versus 60%, 53% versus 36%, and 35% versus 23% respectively. Similar trends were also observed for the rates of complete remission. The poor prognosis of these patients is underlined to some extent by a report from the International Lymphoma Study Group (ILSG) classification,19 which categorized different overall survival rates in lymphoma by histological subtype into 4 broad groupings,23 including: (1) those with 5-year overall survival rate more than 70% including follicular lymphoma, marginal zone B-cell lymphoma of mucosaassociated lymphatic tissue lymphomas (MALT type), and anaplastic lymphoma kinase (ALK) positive anaplastic large T cell lymphoma; (2) histologic subtypes with 5-year survival rates of 50%-70% including small lymphocytic, lymphoplasmacytoid, and nodal marginal zone B-cell lymphomas; (3) lymphomas with 5-year overall survival rates of 30%49% including diffuse large B-cell lymphoma, primary mediastinal large B-cell lymphoma, and the high-grade, B-cell, Burkitt-like and Burkitt lymphomas; and finally, (4) histologic subtypes with the worse overall prognosis and 5-year survival rates less than 30%, including PTCL, precursor T-lymphoblas- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 91 | 12th Congress of the European Hematology Association tic lymphoma, and mantle cell lymphoma. These results have been more recently confirmed by others showing that patients with PTCL have an especially poor outcome with a 5-year overall survival rate of only 26% following treatment with standard doxorubicin containing regimens. Collectively, these observations strongly suggest that patients with T cell lymphoma are in urgent need of additional new treatment options. This is especially true for patients with recurrent or refractory disease who typically have a limited response to salvage therapy and an extremely poor overall survival. First-line treatment of T/NK cell lymphomas The diversity and rarity of T cell lymphomas poses a challenge to the systematic study of these malignancies and the identification of standard therapeutic strategies. Recent reviews have attempted to characterize treatment approaches to PTCL, and to describe new agents that have the potential to act on a variety of these diseases.10,20 The most common types of PTCL have been typically treated with combination chemotherapy programs. Without question, the overwhelming majority of patients with PTCL are initially treated with standard regimens containing cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), though there is certainly no consensus that this represents an acceptable standard up-front treatment program for these patients.11,19,24 The response rates to CHOP chemotherapy for patients with PTCL have been reported to range between 50% and 70%. A variety of other anthracycline-based combination therapies have also seened promising, including infusional treatment programs such as EPOCH which contains etoposide, doxorubicin, vincristine, prednisone and cyclophosphamide.25 Non-alkylator based treatment programs exploiting nucleoside analogs like pentostatin, fludarabine, gemcitabine, and cladribine, as well as monoclonal antibodies/immunotoxins, and high-dose chemotherapy followed by peripheral blood stem cell transplant (PBSCT) have also been used in patients with T cell lymphomas with varying degrees of success.26 Increasingly, more and more patients with T cell lymphomas are being referred for PBSCT in first remission. While early data suggest that these strategies may induce meaningful durable complete remissions, there are no randomized data available that allow us to determine whether PBSCT is superior to other forms of up-front conventional combination chemotherapy programs. These studies are currently being planned. Such treatment approaches should therefore be considered investigational until more definitive data become available. Treatment of relapsed and refractory T cell lymphomas Because T cell malignancies are so uncommon, there are few studies that have specifically investigated optimal treatment pathways for patients with relapsed or refractory disease. High dose therapy followed by an autologous stem cell transplant, or less commonly, an allogeneic stem cell transplant, is a common treatment strategy for patients with relapsed and refractory T cell lymphomas. PBSCT has been successful only in patients with disease responsive to chemotherapy. Patients with refractory disease, or those transplanted with bulky disease do not appear to derive any benefit from high dose chemotherapy.26 A cure may be possible for a small sub-set of patients who have chemosensitive disease and are transplanted in states of minimal residual disease. The remainder of patients who have either refractory disease or are not candidates for PBSCT, are destined to succumb not to survive. It is these patients in particular who are in urgent need of additional treatment options. In order to improve the outcome in this patient population, novel agents need to be developed and integrated into conventional treatment programs to improve treatment outcomes. There have been relatively few studies focusing on identifying novel drugs in the treatment of relapsed T cell lymphomas, although several recent studies have clearly established potentially promising new drugs.27-30 For example, one relatively new drug which is very promising for patients with relapsed or refractory cutaneous T cell lymphoma is gemcitabine, a deoxycytidine analogue. Up till now, most of the data with gemcitabine has focused on the more indolent cutaneous T-cell lymphomas. In one clinical trial exploring the single-agent activity of gemcitabine in cutaneous T cell neoplasms, 10 heavily treated patients received 1,200 mg/m2 of weekly gemcitabine, which produced responses in 6 out of 10 patients, with 2 of these achieving complete remissions.29 The lack of standard response criteria, makes this study data to interpret, however, the median duration of response in this trial was 13.5 months. A similar single-agent experience with gemcitabine in 44 patients with heavily pre treated mycosis fungoides and PTCL revealed a 70% response rate, with an 11% CR rate.30 While these trials are encouraging, it should be emphasised that these trials primarily included patients with cutaneous T-cell lymphoma, primarily MF. Mycosis fungoides is a more indolent form of T-cell NHL, and is not at all representative of the more aggressive forms of T-cell lymphoma which is the subject of this proposal. A detailed experience in aggressive PTCL awaits more focused clinical studies of gemcitabine in this population. Another interesting drug that has been used for decades in the treatment of many lymphoprolifera- | 92 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 tive malignancies, especially T cell malignancies, is deoxycoformycin (pentostatin). Deoxycoformycin has been used with benefit in select patient populations. In one such study, pentostatin was shown to produce an overall response rate of 50% with 7% CRs in patients with relapsed T cell lymphomas (n=14).31 Unfortunately, despite a quite promising ORR, the median duration of response was only 6 months. In another study, pentostatin produced a response rate of 38%, with more than half of these seen in patients with Sézary syndrome.32 Although deoxycoformycin is active in T cell malignancies, response tends to be relatively short and no patients are cured. In addition to traditional cytotoxic chemotherapy programs, it is clear that several exciting and new biological agents appear to act promisingly on T cell malignancies. One of the first agents to prove efficacy in this class of drugs was denileukin diftitox, or ONTAK. ONTAK is a fusion protein that combines the receptor-binding domain of interleukin-2 and diphtheria toxin and is approved for cutaneous T cell lymphoma. Preliminary results from the important study in patients with relapsed/refractory B- and T cell NHL demonstrated an overall response rate of 21% (n=28).33 Responses were seen in both B- and T cell lymphomas as well as CD25+ and CD25- tumors. Given the benefit observed from the addition of rituximab to CHOP in B-cell lymphomas additional studies are now underway to explore the merits of combining ONTAK with conventional CHOP based therapy. Another promising agent is the monoclonal antibody alemtuzumab (Campath), a humanized anti-CD52 monoclonal antibody which has been seen to act in the treatment of relapsed or refractory T cell lymphomas, particularly in T PLL and PTCL. In one clinical trial, Keating et al.34 demonstrated an overall response rate of 51% with an impressive 40% complete remission rate. However, despite the overall response rate, the median time to progression (TTP) was only 4.5 months. Based on the promising action seen in T-PLL, a prospective single agent alemtuzumab Phase 2 trial was conducted strictly in patients with T-PLL. Again, an impressive overall response rate of 76% was observed, with a CR rate of over 60%, and a median disease-free interval of 7 months.35,36 While alemtuzumab can benefit patients with relapsed T cell lymphomas, it is also clear that it is a drug associated with a number of toxicities, which can include the potentially fatal reactivation of cytomegalovirus (CMV). In a study exploring the benefits of alemtuzumab in a wider population of T cell lymphomas, patients were found to have an overall response rate of approximately 35%, though the treatment related mortality was significant at approximately 35%. Furthermore, emerging data now appear to suggest O NH2 H2N N H N N N O OH OH O N H Figure 2. (RS) 10-Propargyl-10deazaaminopterin (Pralatrexate). that the rates of CD52 expression may be lower in patients with PTCL compared to T-PLL, potentially making alemtuzumab a less important drug for other T-cell lymphomas besides T-PLL. Methotrexate, while commonly used in select situations in the treatment of lymphoma, is not routinely used in the treatment of aggressive peripheral T-cell lymphomas. In fact, available literature does not include studies which have systematically addressed the issue of how active MTX is in aggressive PTCL. While it may be integrated into the maintenance treatment of lymphoblastic lymphoma, and is occasionally used in low doses the treatment of cutaneous T-cell disorders37 few if any patients receive MTX as a part of their routine care because of the belief that it has limited action. In fact, one report even suggests that the use of MTX may increase the risk of transformation in mycosis fungoides.38 It may no longer be feasible to conduct a suitably large study of MTX in this patient population because of this and the low number of patients. However, it is clear that the identification of novel antifolates with superior action against lymphoproliferative malignancies represents a valid therapeutic option for these patients, as we will see below. (RS) 10-Propargyl-10deazaaminopterin (Pralatrexate) The 10 deazaaminopterins are a class of folate analogues (Figure 2) that demonstrate greater anti tumor effects than methotrexate against murine tumor models and human tumor xenografts in nude mice.39-41 The improved action is due to the more effective internalization by the 1-carbon, reduced folate transporter (RFC-1) and the subsequent accumulation in tumor cells through the formation of polyglutamylated metabolites. RFC-1 is a fetal oncoprotein that is almost exclusively expressed on fetal and malignant tissue. It is believed to be the principal means through which pralatrexate, though not necessarily all anti-folates, enter the cell. This carrier protein has evolved to efficiently transport reduced natural folates into highly proliferative cells to meet the demands for purine and pyrimidine nucelotides during DNA synthesis. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 93 | 12th Congress of the European Hematology Association Table 3. Biochemical properties of aminopterin, methotrexate, edatrexate, and pralatrexate in CCRF-CEM cells. Treatment Aminopterin Methotrexate Edatrexate Pralatrexate DHFR Inhibition Ki (pM) Influx Km (µM) Vmax (pmol/min/mg protein) 4.9±1 5.4±2 5.8±1 13.4±3 1.2±0.2 4.8±1.0 1.1±0.1 0.3±0.1 3.6±1.0 4.1±1.2 3.9±0.9 3.8±1.3 FPGS Activity Vmax/Km Km (µM) Vmax (pmol/min/mg protein) Vmax/Km 3.0 0.9 3.5 12.6 5.8±1 32.2±5 6.3±1 5.9±1 117±18 70±10 65±9 137±26 20.2 2.2 10.3 23.2 Ki :inhibitory constant; Km:binding constant; mg: milligram; min:minute; pM: picomolar; pmol: picomole; Vmax: maximum rate constant; µM:micromolar. Table 3 demonstrates some of the essential pharmacokinetic properties of pralatexate. As can be seen from the influx Vmax/Km data, pralatrexate is far more efficiently transported than methotrexate being incorporated at a rate nearly 14 times greater. Similarly, the Vmax/Km for the folylpolyglutamyl synthetase (FPGS) mediated glutamylation reactions suggest that pralatrexate is also 10 times more efficiently polyglutamylated compared to methotrexate. These biochemical features suggest that pralatrexate should be a more powerful antineoplastic agent in comparison to methotrexate, and could overcome known mechanisms of MTX resistance where downregulation of RFC-1 and/or FPGS leads to clear MTX resistance. The cytotoxicity of pralatrexate was also compared with that of methotrexate in multiple lymphoma cell lines (1 transformed follicular lymphoma, 2 diffuse large B cell lymphoma, 1 cell Burkitt’s, and 1 Hodgkin’s disease). Pralatrexate demonstrated more than 10 times more cytotoxicity than methotrexate in all cell lines.42 Clinical experience with Pralatrexate in patients with lymphoma Pralatrexate exhibits marked action in T-cell lymphomas Until now, approximately 20 patients with lymphoma have received pralatrexate, including 11 with T-cell lymphoma. Only one of these patients received pralatrexate on an every other week basis, having received a single dose of 135 mg/m2. The remaining were enrolled on the phase I study of weekly pralatrexate. These data demonstrate that the first patient, with a chemotherapy refractory peripheral T-cell lymphoma NOS, experienced a complete remission after a single dose that was documented by PET scan to be PET negative. This patient had a real chemotherapy refractory disease, having received CHOP, ICE and Campath. There had been almost no response to any of these initial therapies. Because he developed gram positive bacteremia from numerous healing skin lesions, he could not be retreated on study (as dictated by the protocol). His response lasted 3 months, and he was the last patient treated on the every other week schedule. The first patient treated on the weekly schedule was a 65 year old woman with T-cell acute lymphoblastic leukemia/lymphoma (T-cell ALL). She had received induction chemotherapy and had been on methotrexate maintenance for nearly 18 months when she developed an aggressive systemic relapse of her disease. There was extensive involvement of her nasal passages, parotid gland, and lacrimal gland, and she experienced difficulty breathing, seeing and walking. She began treatment in dose cohort 1, receiving a dose of 30 mg/m2 weekly for 3 weeks. She experienced a marked improvement in her disease within a week of treatment, with marked resolution of disease in her lacrimal and parotid glands and nasal passages. She achieved a documented complete remission by PET and CT, and had a morphologically normal bone marrow which was more than 35% infiltrated with ALL lymphoblasts prior to pralatrexate administration. She was maintained on treatment for 12 months, after which she developed a bone marrow only relapse. A second patient treated at this dose level with chemotherapy refractory HTLV-1 ATLL which progressed rapidly after infusional EPOCH and interferon/Combivir also experienced a complete remission to pralatrexate. He presented with a pathologically proven relapse in the axilla that was non-bulky, and had also been maintained on therapy for 12 months. He is currently in CR. The other patient in this dose cohort with a NK/T-cell lymphoma, achieved a mixed response, having had resolution of her prior disease, but developing a lesion on the tibial plateau requiring radiation therapy. Escalation of pralatrexate to 30 mg/m2 weekly for 6 weeks was well tolerated, with no DLTs in the cohort studied. The first patient enrolled on this dose cohort also had real chemotherapy refractory panniculitic T-cell lymphoma. This particular disease actually belongs to a more aggressive and very poor prognosis sub-set of Tcell lymphomas, namely the ???-T-cell receptor rearranged T-cell malignancies. This patient relapsed following standard chemotherapy for this disease, and achieved a CT, PET and pathologically confirmed complete remission after two cycles of pralatrexate. This response has been maintained and he now has the | 94 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 option to undergo an unmatched allogeneic stem cell transplant in CR. The only patients with T-cell lymphoma to actually progress on the study drug carried a diagnosis of angioimmunoblastic T-cell lymphoma, both of whom received at least two cycles of pralatrexate. The two patients who died from infectious complications following treatment and regression of their lymphoma were discussed above. Both experienced objective disease regression, but were not assessable for response having per protocol not completed a cycle of therapy. At the 45 mg/m2 dose level, another patient with blastic NK/T-cell lymphoma of the skin and blood achieved a rapid complete remission based on complete blood counts, clinical findings and photodocumentation. Now 4 months after registration he continues on study without any obvious toxicities. One patient with ALK positive anaplastic large T-cell lymphoma (ALCL) is still within the first cycle of therapy, and has not yet been evaluated for response. To summarize, of the 11 patients with T-cell lymphoma treated with pralatrexate (on a Phase 1 study), 5 have experienced complete remissions, with durations of response lasting 12, 12+, 9, 3, and 4+ months respectively. Two of the eleven patients died from infectious complications of their disease treatment, both experiencing objective regressions of their lymphoma. Two experienced mixed responses, and 2 patients with angioimmunoblastic lymphoma experienced disease progression. One of two patients with diffuse large B-cell lymphoma in the ongoing weekly pralatrexate study has recently experienced a partial remission. Conclusions It is clear that there are many new drugs in clinical practice. A wide range of novel targets effecting such unique pathways as the Bcl-2 family members, proteasome, histone deacetylase, MAP kinase and AKT and mTOR for example, offer exciting and unique opportunities to change the natural history of these diseases. Furthermore, many of these agents appear to increase the effects of conventional cytotoxic therapy. What remains most challenging however, is the fact that diseases like mantle cell lymphoma and Tcell lymphoma are exceedingly rare diseases. Our new understanding of biology, has rapidly outpaced our ability to test new hypotheses in patients with these diseases. The most significant breakthroughs will only appear if we can continue to collaborate as one community with a shared interest, and put all patients with T-cell lymphoma on clinical trials. It will be the constant transition of strategies from the laboratory to the ward that will make the biggest impact on the quality of our patients’ lives. References 1. Zheng T, Mayne ST, Boyle P, et al. Epidemiology of nonHodgkin lymphoma in Connecticut. 1935-1988. Cancer 1992;70:840-9. 2. Cartwright RA, Gilman EA, Gurney KA. Time trends in incidence of haematological malignancies and related conditions. Br J Haematol 1999;106:281-95. 3. Surveillance E, and End Results (SEER) Program: (www.seer.cancer.gov/publicdata) SEER Stat Database: Incidence-SEER 9 Regs Public Use. Nov 2003 Sub (1973-2001), National Cancer Institute, DCCPS, Surveillance Research Program, Cancer Statistics Branch, released April 2004, based on the November 2003 submission. 4. Dorn HF CS. Morbidity from cancer in the United States Washington: US Government Printing Office 1958. 5. Devesa SS, Fears T. Non-Hodgkin's lymphoma time trends: United States and international data. Cancer Res 1992;52: 5432s-40s. 6. Liu S, Semenciw R, Mao Y. Increasing incidence of nonHodgkin's lymphoma in Canada, 1970-1996: age-periodcohort analysis. Hematol Oncol 2003;21:57-66. 7. Gail MH PJ, Rabkin CS. Projections of the incidence of nonHodgkin's lymphoma related to acquired immunodeficiency syndrome. J Natl Cancer Inst 1991;83:695-701. 8. A clinical evaluation of the International Lymphoma Study Group classification of non-Hodgkin's lymphoma. The NonHodgkin's Lymphoma Classification Project. Blood 1997;89:3909-18. 9. Morton LM, Wang SS, Devesa SS, et al. Lymphoma incidence patterns by WHO subtype in the United States, 1992-2001. Blood 2005. 10. Rizvi MA, Evens AM, Tallman MS, et al. T-cell non-Hodgkin lymphoma. Blood 2006;107:1255-64. 11. Savage KJ CM, Gascoyne RD. Characterization of peripheral T-cell lymphomas in a single North American insitution by thw WHO classification. Ann Oncol 2004;15:1467-75. 12. Evens AM. Treatment of T-cell non-Hodgkin's lymphoma. Curr Treat Options Oncol 2004;5:289-303. 13. Reiser M. T-cell non-Hodgkin's lymphoma in adults: clinicopathological characteristics, response to treatment and prognostic factors Leuk Lymphoma 2002;43:805-11. 14. Dearden CE, Foss FM. Peripheral T-cell lymphomas: diagnosis and management. Hematol Oncol Clin North Am 2003;17: 1351-66. 15. Jaffe E. World Health Organization. pathology and genetics of tumours of haematopoietic and lymphoid tissues. Lyon: IARC Press, 2001. 16. Shipp MA. Prognostic factors in aggressive non-Hodgkin's lymphoma: who has high-risk disease? Blood 1994; 83:116573. 17. Armitage JO, Weisenburger DD. New approach to classifying non-Hodgkin's lymphomas: clinical features of the major histologic subtypes. Non-Hodgkin's Lymphoma Classification Project. J Clin Oncol 1998;16:2780-95. 18. Lopez-Guillermo A, Cid J, Salar A, et al. Peripheral T-cell lymphomas: initial features, natural history, and prognostic factors in a series of 174 patients diagnosed according to the R.E.A.L. Classification. Ann Oncol 1998;9:849-55. 19. Rudiger T, Weisenburger DD, Anderson JR, et al. Peripheral Tcell lymphoma (excluding anaplastic large-cell lymphoma): results from the Non-Hodgkin's Lymphoma Classification Project. Ann Oncol 2002;13:140-9. 20. Campo E, Gaulard P, Zucca E, et al. Report of the European Task Force on Lymphomas: workshop on peripheral T-cell lymphomas. Ann Oncol 1998;9:835-43. 21. Sonnen R, Schmidt WP, Muller-Hermelink HK, et al. The International Prognostic Index determines the outcome of patients with nodal mature T-cell lymphomas. Br J Haematol 2005;129:366-72. 22. Gisselbrecht C, Gaulard P, Lepage E, et al. Prognostic significance of T-cell phenotype in aggressive non-Hodgkin's lymphomas. Groupe d'Etudes des Lymphomes de l'Adulte (GELA). Blood 1998;92:76-82. 23. Harris NL, Jaffe ES, Stein H, et al. A revised EuropeanAmerican classification of lymphoid neoplasms: a proposal from the International Lymphoma Study Group. Blood 1994; 84:1361-92. 24. Fisher RI, Gaynor ER, Dahlberg S, et al. Comparison of a standard regimen (CHOP) with three intensive chemotherapy regimens for advanced non-Hodgkin's lymphoma. N Engl J Med 1993;328:1002-6. 25. Wilson WH, Grossbard ML, Pittaluga S, et al. Dose-adjusted Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 95 | 12th Congress of the European Hematology Association 26. 27. 28. 29. 30. 31. 32. 33. 34. EPOCH chemotherapy for untreated large B-cell lymphomas: a pharmacodynamic approach with high efficacy. Blood 2002; 99:2685-93. Horwitz S MC, Kewalramani T, et al. Second-Line therapy with ICE Followed by High Dose Therapy and Autologous Stem Cell Transplantation for Relapsed/Refractory Peripheral T-Cell Lymphomas; Minimal Benefit When Analyzed by Intent to Treat. Blood 2005;106:752a. Marchi E, Alinari L, Tani M, et al. Gemcitabine as frontline treatment for cutaneous T-cell lymphoma: phase II study of 32 patients. Cancer 2005;104:2437-41. Nabhan C, Krett N, Gandhi V, et al. Gemcitabine in hematologic malignancies. Curr Opin Oncol 2001;13:514-21. Sallah S, Wan JY, Nguyen NP. Treatment of refractory T-cell malignancies using gemcitabine. Br J Haematol 2001;113:1857. Zinzani PL, Baliva G, Magagnoli M, et al. Gemcitabine treatment in pretreated cutaneous T-cell lymphoma: experience in 44 patients. J Clin Oncol 2000;18:2603-6. Escalon MP, Liu NS, Yang Y, et al. Prognostic factors and treatment of patients with T-cell non-Hodgkin lymphoma: the M. D. Anderson Cancer Center experience. Cancer 2005;103: 2091-8. Dearden C, Matutes E, Catovsky D. Deoxycoformycin in the treatment of mature T-cell leukaemias. Br J Cancer 1991;64: 903-6. Dang NH HF, Fayad L, et al. Interim analysis of a phase II of denileukin diftitox (ONTAK) for B and T-cell non-Hodgkin's lymphoma. 2003;22:570. Keating MJ, Cazin B, Coutre S, et al. Campath-1H treatment of T-cell prolymphocytic leukemia in patients for whom at least one prior chemotherapy regimen has failed. J Clin Oncol 2002;20:205-13. 35. Dearden CE, Matutes E, Cazin B, et al. High remission rate in T-cell prolymphocytic leukemia with CAMPATH-1H. Blood 2001;98:1721-6. 36. Enblad G, Hagberg H, Erlanson M, et al. A pilot study of alemtuzumab (anti-CD52 monoclonal antibody) therapy for patients with relapsed or chemotherapy-refractory peripheral T-cell lymphomas. Blood 2004;103:2920-4. 37. Abd-el-Baki J, Demierre MF, Li N, et al: Transformation in mycosis fungoides: the role of methotrexate. J Cutan Med Surg 2002;6:109-16. 38. Sarris AH, Phan A, Duvic M, et al. Trimetrexate in relapsed Tcell lymphoma with skin involvement. J Clin Oncol 2002; 20:2876-80. 39. Schmid FA, Sirotnak FM, Otter GM, et al. New folate analogs of the 10-deaza-aminopterin series: markedly increased antitumor activity of the 10-ethyl analog compared to the parent compound and methotrexate against some human tumor xenografts in nude mice. Cancer Treat Rep 1985;69:551-3. 40. Sirotnak FM, DeGraw JI, Moccio DM, et al. New folate analogs of the 10-deaza-aminopterin series. Basis for structural design and biochemical and pharmacologic properties. Cancer Chemother Pharmacol 1984;12:18-25. 41. Sirotnak FM, DeGraw JI, Schmid FA, et al. New folate analogs of the 10-deaza-aminopterin series. Further evidence for markedly increased antitumor efficacy compared with methotrexate in ascitic and solid murine tumor models. Cancer Chemother Pharmacol 1984;12:26-30. 42. Wang ES, O'Connor O, She Y, et al. Activity of a novel antifolate (PDX, 10-propargyl 10-deazaaminopterin) against human lymphoma is superior to methotrexate and correlates with tumor RFC-1 gene expression. Leuk Lymphoma 2003; 44:1027-35. | 96 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Myeloma Advances in myeloma biology: basis for new therapy N.C. Munshi Jerome Lipper Multiple Myeloma Center Dana-Farber Cancer Institute Boston VA Healthcare System Harvard Medical School Boston, MA, USA Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:97-101 espite the advances in conventional and high dose chemotherapy, Multiple myeloma (MM) remains incurable. To overcome resistance to current therapies and improve patient outcome, novel biologically-based treatment approaches are being developed based upon targeting the MM cell as well as its BM microenvironment, and to target mechanisms whereby MM cells grow and survive in the bone marrow (BM).1 To achieve this goal, we and others have defined oncogenomic changes, at both genomic and expression level, that characterize the myeloma cells, and developed model systems to study growth, survival, and drug resistance mechanisms intrinsic to MM cells. Importantly, both in vitro systems and in vivo animal models characterize mechanisms of MM cell homing to BM, as well as factors (MM cell-bone marrow stromal cell interactions, cytokines, angiogenesis) promoting MM cell growth, survival, drug resistance, and migration in the BM microenvironment.2 These model systems have already stimulated the development of several promising biologically-based therapies including thalidomide (Thal) and its more potent immunomodulatory analog lenalidomide,3 as well as proteasome inhibitor Bortezomib4 which can overcome classical drug resistance and improve patient outcome. The identification of new targets and the development of newer agents is now predicated based on a further understanding of genomic studies in MM and on understanding of role of BM microenvironment on myeloma pathobiology. We here describe the recent advances that have helped the development of novel tagets and agents in MM and which form the basis for their clinical investigation. D Cytogenetic and genomic studies in MM Recent genomics and proteomics studies in MM have improved our understanding of myeloma pathobiology, allowed for molecular classification, identified novel therapeutic targets, and provided the scientific rationale combination therapies to increase tumor cell cytotoxicity and overcome drug resistance. Most if not all MM harbours cytogenetic abnormalities including numerical abnormality with hyperdiploid karyotypes with infrequent translocations (<30%) or nonhyperdiploid karyotypes with high prevalence of translocations involving Ig gene.5 The chief characteristic of translocations in B cell malignancies as well as myeloma is translocations involving chromosome 14q32.6 In one third of the patients these translocations involve chromosomal locus 11q13 (cyclin D1), and lead to cyclin D1 upregulation or, indirectly through other intermediate transcriptional factors, upregulation of cyclin D2 and D3. Upregulation of cyclin D genes may render plasma cells responsive to proliferative stimuli as well as further genomic changes.7 Cyclin D therefore has become important target for prognostic classification as well as therapeutic target in myeloma.8 Another oncogene dysregulated by t(4;14) translocation is the fibroblast growth factor receptor 3 (FGFR3) gene. Ectopic expression of FGFR3 promotes MM cell proliferation and prevents apoptosis.9,10 It is oncogenic in a murine model, as evidenced by transformation of hemopoietic cells. FGFR3 has become a focus of intense therapeutic interest with a number of small molecular FGFR3 inhibitors being evaluated in preclinical as well as clinical studies. This translocation also involves a novel gene MMSET with resultant IgH/MMSET hybrid transcripts.11 The less frequent chromosomal partner in 14q32 translocation are 8q24 (c-myc) 18q21 (bcl-2), 11q23 (MLL-1), 16q23 (cmaf) and 6p25 (IRF)11 all with potential therapeutic interest. Clinical studies have shown that MM patients with t(4;14), or t(14;16) translocations or chromosome 13 or 17p deletions1,5 have a poor prognosis with conventional or high-dose therapies. However, recent studies using novel Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 97 | 12th Congress of the European Hematology Association Cytokines IL-6, IGF-1, VEGF, Il21, TNF-α, SDF-1 Ras JAK Raf MEK p42/44 MAPK Proliferation Bcl-xL Mcl-1 STAT3 MM-BMSC Adhesion Drug resistance antiapoposis mTOR Bad PI3-K Akt (PKB) NF-κB cyclin D FKHR p27 PKC Table 1. Cell surface adhesion molecules on MM cells and BMSCs. MM CELL BMSC CD56 LFA-1 CD38 VLA-4 VLA-5 Syndecan HSP ICAM-1 CD31 VCAM-1 ECM Fibronectin Fibronectin Type I Collagen HSP = Heparan Sulfate Proteoglycan; ECM = Extra Cellular Matrix. agents have demonstrated the ability of both bortezomib and Lenalidomide to overcome the adverse effects of these genetic factors on patient outcome.12 Recently studies with high-resolution analysis of recurrent copy number alterations (CNAs) using array based comparative genomic hybridization (aCGH) and its integration with expression profiling data have identified areas of chromosomal amplifications and deletions in both MM cell lines as well as primary patient samples. These studies have provided a DNA based classification systems for MM and have also defined 87 discrete minimal common regions (MCRs) within recurrent and highly focal CNAs. In this study, integration with expression data has generated a list of MM gene candidates within these MCRs, improving our understanding of the disease pathogenesis, and promoting the identification of targeted drugs.13 Transcriptomic changes in MM Gene microarray profiling has shown that the expression profile of monoclonal Gammopathy of Undetermined Significance (MGUS) and MM is similar but distinct from that of normal plasma cells. These studies have defined the changes associated Celicycle Migration Figure 1. Signaling cascades mediating growth, survival, drug resistance and migration in MM cells. with the progression of normal plasma cells to MGUS and then to multiple myeloma.14 These studies have provided the basis for RNA based prognostic classification.8 Along with aCGH studies, expression profile has also identified novel therapeutic targets including potential novel targets on cell surface for monoclonal antibody development, intracellular targets for development of small molecule inhibitors, and targets for immune-based therapies. Expression profiling preand post-therapeutic intervention have allowed for identification of gene expression patterns that can predict response versus resistance to therapy. These results are likely to lead to expression-based individualized therapy in the future. Bone marrow microenvironment and MM cell interaction We and others have characterized the mechanisms whereby MM cells home to the BM and adhere to BM stromal cells (BMSCs) and extracellular matrix (ECM) protein.15 These studies have identified adhesion molecules mediating MM cell binding to fibronectin and BMSCs (Table 1) and lead to MM cell growth, survival, anti-apoptosis as well as development of drug resistance. Besides the adhesion mediated signaling, the binding leads to secretion of various growth promoting cytokines by both MM cells as well as BMSC. BMSCs secrete cytokines, such as interleukin-6 (IL-6),16 insulin-like growth factor-1 (IGF-1),17 vascular endothelial growth factor (VEGF),18 and stomal cell derived growth factor (SDF-1)α,19 which increase MM cell growth, survival, and the development of drug resistance via MAPK and PI3K/Akt, Jak/STAT, and PI3-K/Akt signaling cascades, respectively (Figure 1).2 IGF-1 has been shown to increase MM cell growth, survival, and drug resistance.17 VEGF secreted by both MM cells and BMSCs is upregulated by the binding of MM cells to BMSCs. | 98 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 It space increases MM cell growth angiogenesis, although reports correlate an increase in angiogenesis with MM stage its precise pathophysiologic significance in MM BM is undefined. VEGF induces migration via PKC signaling.18 Tumor necrosis factorα (TNFα)? does not directly alter MM cell growth and survival. However, it induces NF-κB dependent upregulation of adhesion molecules (ICAM-1, VCAM-1) on both MM cells and BMSCs, resulting in increased binding and related induction of IL-6 and other cytokine secretions.20 The role of other cytokine such as Hepatocyte Growth Factor (HGF), IL-15 and IL-21 in MM cell growth and survival has been described.21, 22 Recombinant IL-1β stimulates IL6 production and thereby MM cell proliferation increases leading to investigation of anti- IL-1β in MGUS. Transforming growth factor-β (TGF-β) is secreted by MM cells and triggers IL-6 secretion in BMSCs and paracine IL-6 mediated tumor cell growth. TGF-β secreted by MM cells probably also contributes to the immunodeficiency characteristic of MM by downregulating B cells, T cells, and natural killer cells, without similarly inhibiting the growth of MM cells.23 Macrophage inflammatory protein-1α (MIP-1α) is an osteoclast stimulating factor in MM.24 Expression profile studies of MM cells and BMSC following their adhesion in both in vitro and in vivo models of human MM in mice have identified upregulation of growth, survival, and drug resistance genes in MM cells; upregulation of adhesions molecules on MM cells and BMSCs, and changes in cytokines in BMSCS.25 This MM-BMSC and MM-ECM interaction confers cell adhesion mediated (CAM) drug resistance to conventional agents with induction of p27 and G1 growth arrest and also induces melphalan resistance.26,27 However, the novel agents including Thalidomide (Thal) and its immunomodulatory derivative lenalidomide, as well as proteasome inhibitor Bortezomib,3,28 target both MM cells as well as its microenvironment and are able to overcome CAM drug resistance to conventional agents. These newer agents work through various mechanisms operative in the BM environment. Besides the variable extent of activity on MM cells themselves, they inhibit MM-BMSC interaction and the consequent local cytokine production, and they decrease VEGF and FGF secretion which are important for neoangiogenesis.3,28 Lenalidomide, and to some extent thalidomide, also have significant immune effects including improving the antigen presenting function of dendritic cells, co-stimulation of T cells via the B7-CD28 pathway and, by secretion of IL-2, it upregulates T and NK cell anti-MM activity.29 Lenalidomide can also upregulate antibody dependent celluar mediated cytotoxicity.30 Molecularly based rational combination therapies The improved understanding of the molecular changes in MM and the effects of various agents on gene expression as well as signaling profiles have led to the development of molecularly-based rational combination therapies. The molecular studies have defined the mechanism of apoptosis by various agents and discovered mechanisms of drug resistance. Exciting, preclinical studies suggest improved activity when these novel agents are combined with conventional agents or with each other. These studies have established a new treatment paradigm targeting the MM cell in its BM microenvironment to further clarity MM pathogenesis as well as overcome drug resistance and improve patient outcome. Expression profiling of MM cells following their treatment with various agents can provide the preclinical rationale for combining novel targeted therapies. For example, expression profile of MM cells following Bortezomib treatment demonstrates induction of various pathways’ upregulation of both ubiquitin/proteasome and stress response gene transcripts,28 specifically Hsp90, which plays a major role in protein folding and ubiquitin-mediated proteasomal protein degradation. In vitro studies show that Hsp90 inhibition by 17AAG can block the Hsp90 stress response induced by Bortezomib and thereby increase MM cell apoptosis.31 These expression profile studies therefore provided the framework for a clinical trial coupling Hsp90 inhibitor KOS953 with Bortezomib to enhance MM cells cytotoxicity and even overcome Bortezomib resistance.32 Similarly, expression as well as proteomic changes following Bortezomib treatment suggested that Bortezomib inhibited DNA repair.33 Subsequent in vitro studies confirmed that combining Bortezomib with DNA damaging agents (alkylating agents and anthracyclines) can improve sensitivity or even overcome resistance to these agents in MM. Already clinical protocols combining Velcade with Doxil and with melphalan are producing very promising clinical results. The apoptotic signaling cascades triggered in MM cells by both conventional and novel agents have been characterized. For example, use of lenalidomide with Bortezomib triggers both caspase 8 and caspase 9-mediated MM cell death.34 An ongoing clinical trial has demonstrated remarkable activity in patients treated with combination lenalidomide and Bortezomib even in patients resistant to either agent alone.35 MM cell signaling studies have defined the role of the aggresome in degrading ubiquitinated protein in MM. Blocking the aggresome with HDAC6 inhibitor tubacin induces a compensatory upregulation of the proteasome while, blocking the proteasome with Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 99 | 12th Congress of the European Hematology Association Bortezomib triggers a compensatory upregulation of the aggresome. Blocking both the proteasome and aggresome with Bortezomib and tubacin respectively induces synergistic toxicity.36 The HDAC inhibitor LBH596 is under clnical investigation singly and in combination with Bortezomib.37 mTOR inhibitor rapamycin sensitizes MM cells to both conventional (dexamethasone) and novel therapies.38 Bortezomib inhibits growth (MEK/ERK) and survival (Jak/STAT) signaling, but activates Akt, providing the preclinical rationale for combining Bortezomib with the Akt inhibitor perifosine.39 Gene expression profiling of patient tumor samples has also identified genes associated with lack of response to Bortezomib. Hsp27 upregulation correspond to intrinsic or acquired Bortezomib resistance. Preclinical studies showed that p38MAPK inhibition downregulated Hsp27 expression and restored velcade sensitivity in resistant MM cell lines providing the basis for a trial combining these two agents.40 Finally, the immunomodulatory agent Lenalidomide can markedly increase antibody-dependent cellular cytotoxicity (ADCC) providing the rationale to combine monoclonal antibodies with novel drugs.30 Once the in vitro potential of these novel agents is demonstrated, they are tested for their efficacy in murine models. Novel murine models simulating human MM have been developed to improve our ability to confirm novel targets and agents in MM. A SCID mice bearing human bone41 and a conditional tranagenic mouse model expressing xbp-1 gene that develops MGUS and MM with characteristics similar to human MM provides such tools.42 Thalidomide, Lenalidomide and Bortezomib all inhibit human MM cell growth, decrease associated angiogenesis, and prolong host survival in animal models. These agents have already demonstrated marked clinical anti-MM activity confirming the usefulness of preclinical models to identify and confirm novel therapeutics and their approval for clnical use in patients with newlydiagnosed myeloma (Thalidomide) and with relapsed myeloma (Bortezomib and Lenalidomide). Ultimately, it may be possible to carry out gene and protein expression profiling on individual patient samples to allow the selection of those agents most likely to be effective. For example, a comparison of gene expression profile of patient MM cells to normal twin plasma cells showed surprisingly few significant differences.43 This data may allow the selection of those combinations of agents targeting these gene products to optimize clinical response. References 1. Hideshima T, Bergsagel PL, Kuehl M, Anderson KC. Advances in biology of multiple myeloma: clinical applications. Blood 2004;104:607-18. 2. Hideshima T, Anderson KC. Molecular mechanisms of novel therapeutic approaches for multiple myeloma. Nat Rev Cancer 2002;2:927-37. 3. Hideshima T, Chauhan D, Shima Y, Raje N, Davies FE, Tai YT, et al.Thalidomide and its analogues overcome drug resistance of human multiple myeloma cells to conventional therapy. Blood 2000;96:2943-50. 4. Hideshima T, Chauhan D, Hayashi T, Akiyama M, Mitsiades N, Mitsiades C, et al. Proteasome inhibitor PS-341 abrogates IL-6 triggered signaling cascades via caspase-dependent downregulation of gp130 in multiple myeloma. Oncogene 2003;22:8386-93. 5. Fonseca R, Harrington D, Oken MM, Dewald GW, Bailey RJ, Van Wier SA, et al. Biological and prognostic significance of interphase fluorescence in situ hybridization detection of chromosome 13 abnormalities (delta13) in multiple myeloma: an Eastern co-operative oncology group study. Cancer Res 2002;62:715-20. 6. Bergsagel PL, Nardini E, Brents L, et al. IgH translocations in multiple myeloma: a nearly universal event that rarely involves c-myc. Curr Topics Microbiol Immunol in press. 7. Fonseca R, Blood EA, Oken MM, Kyle RA, Dewald GW, Bailey RJ, Vet al. Myeloma and the t(11;14)(q13;q32); evidence for a biologically defined unique subset of patients. Blood 2002;99:3735-41. 8. Bergsagel DE, Kuehl M, Zhan F, Sawyer J, Barlogie B, Shaughnessy J. Cyclin D dysregulation: an early and unifying pathogenic event in multiple myeloma. Blood 2005;106:296303. 9. Plowright EE, Li Z, Bergsagel PL, Chesi M, Barber DL, Branch DR, Hawley RG, et al. Ectopic expression of fibroblast growth factor receptor 3 promotes myeloma cell proliferation and prevents apoptosis. Blood 2000;95:992-8. 10. Chesi M, Nardini E, Lim RSC, Smith KD, Kuehl WM, Bergsagel PL. The t(4;14) translocation in myeloma dysregulates both FGFR3 and a novel gene, MMSET, resulting in IgH/MMSET hybrid transcripts. Blood 1998;92:3025-34. 11. Kuehl WM, Bergsagel PL. Multiple myeloma: evolving genetic events and host interactions. Nat Rev Cancer 2002;2:175-187. 12. Jagannath S, Richardson PG, Sonneveld P, Schuster MW, Irwin D, Stadtmauer E, et al. Bortezomib appears to overcome the poor prognosis conferred by chromosome 13 deletion in phase 2 and 3 trials. Leukemia 2007;21:151-7. 13. Carrasco DR, Tonon G, Huang Y, Zhang Y, Sinha R, Feng B, et al. High-resolution genomic profiles define distinct clinicopathogenetic subgroups of multiple myeloma patients. Cancer Cell 2006;9:313-25. 14. Davies F, Dring AM, Li C, Rawstron AC, Shammas MA, Fenton JAL, et al. Insights into the multistep transformation of MGUS to myeloma using microarray expression analysis. Blood 2003;102:4504-11. 15. Mitsiades C, Mitsiades N, Munshi N, Richardson PG, Anderson KC. The role of the bone marrow microenvironment in the pathophysiology and therapeutic management of multiple myeloma; interplay of growth factors, their receptors, and stromal interactions. Eur J Hemaol 2006;42:1564-73. 16. Chauhan D, Uchiyama H, Akbarali Y, Urashima M, Yamamoto KI, Libermann TA,et al. Multiple myeloma cell adhesion-induced interleukin-6 expression in bone marrow stromal cells involves activation of NF-κB. Blood 1996;87: 1104-12. 17. Mitsiades C, Mitsiades N, McMullan CJ, Poulaki V, Shringarpure R, Akiyama M, et al. Inhibition of insulin-like growth factor receptor-1 tyrosine kinase activity as a therapeutic strategy for multiple myeloma, other hematologic malignancies, and solid tumors. Cancer Cell 2004;5:221-30. 18. Podar K, Tai YT, Lin BK, Narsimhan RP, Sattler M, Kijima T, et al. Vascular endothelial growth factor-induced migration of multiple myeloma cells is associated with beta 1 integrin- and phosphatidylinositol 3-kinase-dependent PKC alpha activation. J Biol Chem 2002;277:7875-81. | 100 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 19. Hideshima T, Chauhan D, Hayashi T, Podar K, Akiyama M, Gupta D, et al. The biologic sequelae of stromal cell derived1a in multiple myeloma. Mol Cancer Ther 2002;1:539-544. 20. Hideshima T, Chauhan D, Schlossman RL, Richardson PR, Anderson KC: Role of TNF-alpha in the pathophysiology of human multiple myeloma: therapeutic applications. Oncogene 2001;20:4519-27. 21. Brenne AT, Baade Ro T, Waage A, Sundan A, Borset M, Hjorth-Hansen H. Interleukin-21 is a growth and survival factor for human myeloma cells. Blood 2002;99:3756-62. 22. Hjertner O, Torgersen ML, Seidel C, Hjorth-Hansen H, Waage A, Borset M, et al. Hepatocyte growth factor (HGF) induces interleukin-11 secretion from osteoblasts: a possible role for HGF in myeloma-associated osteolytic bone disease. Blood 1999;94:3883-8. 23. Hayashi T, Hideshima T, Nguyen AN, Munoz O, Podar K, Hamasaki M, et al. TGF-b receptor I kinase inhibitor downregulates cytokine secretion and multiple myeloma cell growth in the bone marrow microenvironment. Clin Cancer Res 2004;10:7540-6. 24. Han JH, Choi SJ, Kurihara N, Koide M, Oba Y, Roodman GD. Macrophage inflammatory protein-1alpha is an osteoclastogenic factor in myeloma that is independent of receptor activator of nuclear factor kappaB ligand. Blood 2001;97:3349-53. 25. Mitsiades CS, Mitsiades NS, McMullan C, Poulaki V, Hideshima T, Chauhan D, et al. Transcriptional profiles of the interactions of multiple myeloma cells with their local bone marrow micronenvironment: implications for rational design of novel anti-tumor therapies. Proc Natl Acad Sci USA 2004;submitted. 26. Damiano JS, Cress AE, Hazlehurst LA, Shtil AA, Dalton WS. Cell adhesion mediated drug resistance (CAM-DR): Role of integrins and resistance to apoptosis in human myeloma cell lines. Blood 1999;93:1658-67. 27. Dalton WS: The tumor microenvironment as a determinant of drug response and resistance. 1999;2:285-8. 28. Mitsiades N, Mitsiades C, Poulaki V, Chauhan D, Gu X, Bailey C, Joseph M, et al. Molecular sequelae of proteasome inhibition in human multiple myeloma cells. Proc Natl Acad Sci USA 2002;99:14374-9. 29. LeBlanc R, Hideshima T, Catley LP, Shringapure R, Burger R, Mitsiades N, et al. Immunomodulatory drug (Revamid) costimulates T cells via the B7-CD28 pathway. Blood 2004;103:1787-90. 30. Tai YT, Li SF, Catley L, Coffey R, Breitkreutz I, Bae J, et al. Immunomodulatory drug lenalidomide augments anti-CD40induced cytotoxicity in human multiple myeloma: clinical implications. Cancer Res 2005;65:11712-20. 31. Mitsiades CS, Mitsiades NS, McMullan CJ, Poulaki V, Kung AL, Davies FE, et al. Anti-myeloma activity of heat shock protein-90 inhibition. Blood 2006;107:1092-100. 32. Chanan-Khan A, Richardson PG, Alsina M, Carroll M, Lonial S, Krishan A, et al. Phase I clinical trial of KOS 953+ Bortezomib in relapsed refractory multiple myeloma. Blood 2005;106-109a. 33. Mitsiades N, Mitsiades C, Richardson PG, Poulaki V, Tai YT, Chauhan D, et al. The proteasome inhibitor PS-341 potentiates sensitivity of multiple myeloma cells to conventional chemotherapeutic agents: therapeutic applications. Blood 2003;101:2377-80. 34. Mitsiades N, Mitsiades CS, Poulaki V, Chauhan D, Richardson PG, Hideshima T, et al. Apoptotic signaling induced by immunomodulatory thalidomide analogs in human multiple myeloma cells: therapeutic implications. Blood 2002;99:452530. 35. Richardson PG. Phase I study of the safety and efficacy of Bortezomib in combination with Revlimid in relapsed and refractory myeloma: the revvel study. Haematologica 2005;90 (s1):PL5.04 (abstr). 36. Hideshima T, Bradner J, Wong J, Chauhan D, Richardson P, Shreiber SL, et al. Small molecule inhibition of proteasome and aggresome function induces synergistic anti-tumor activity in multiple myeloma: therapeutic implications. Proc Natl Acad Sci USA 2005;102:8567-72. 37. Catley L, Weisberg E, Kiziltepe T, Tai YT, Hideshima T, Neri P, et al. Aggresome induction by proteasome inhibitor bortezomib and a-tubulin hyperacetylation by tubulin deacetylase (TDAC) inhibitor LBH589 are synergistic in myeloma cells. Blood 2006;108:3441-9. 38. Raje N, Kumar S, Hideshima T, Ishitsuka K, Chauhan D, Mitsiades C, et al. Combination of the mTOR inhibitor Rapamycine and Revlimid has synergistic activity in multiple myeloma. Blood 2004;104:4188-93. 39. Hideshima T, Catley L, Yasui H, Ishitsuka K, Raje N, Mitsiades C, et al. Perifosine, an oral bioactive novel alkyl-lysophospholipid, inhibits Akt and induces in vitro and in vivo cytotoxicity in human multiple myeloma cells. Blood 2006;107:4053-62. 40. Hideshima T, Akiyama M, Hayahi T, Richarson P, Schlossman R, Chauhan D, et al. Targeting p38MAPK inhibits multiple myeloma cell growth in the bone marrow milieu. Blood 2003;101:703-5. 41. Tassone P, Neri A, Burger R, Carrasco DR, Goldmacher V, Fram R, et al. A clinically relevant SCID-hu in vivo model of human multiple myeloma. Blood 2005;106:713-6. 42. Carrasco DR, Sukhdeo K, Protopopova M, Sinha R, Enos M, Carrasco DE, et al. The differentiation and stress response factor XBP-1 drives multiple myeloma pathogenesis. Cancer Cell 2007; in press. 43. Munshi N, Hideshima T, Carrasco R, Shammas MA, Auclair D, Davies F, et al. Identification of genes modulated in multiple myeloma using genetically identical twin samples. Blood 2004;103:1799-806. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 101 | Myeloma Multiple myeloma: diagnosis, staging and criteria of response J. Bladé Haematology Department, Institute of Hematology and Oncology, Hospital Clínic, IDIBAPS, Barcelona, Spain Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:102-107 onoclonal gammopathies are characterized by the existence of a plasma cell clone which produces a monoclonal protein (M-protein, paraprotein or M-component). The clinical spectrum ranges from asymptomatic disorders such as monoclonal gammopathy of undetermined significance (MGUS) or smoldering multiple myeloma (SMM) to symptomatic multiple myeloma (MM). When the light chain is amyloidogenic the clinical picture is that of primary systemic amyloidosis (AL) which results from the tissue and organ light chains deposition. The median survival of patients with MM is approximately 3 years. However, this varies considerably from patient to patient. Finally, the plasma cell clone has been classically characterized by a high degree of resistance to treatment, and different degrees of response must be considered. The introduction of high-dose therapy/stem cell transplantation (HDT/SCT) and the availability of new drugs with novel mechanisms of action has resulted in a higher tumor reduction with a significant number of patients achieving complete remission. For this reason, new response criteria were developed. These have been recently revisited. In this overview, the differential diagnosis among the above mentioned monoclonal gammopathies with the criteria for symptomatic disease, the prognostic factors/staging systems and the criteria of response for MM are reviewed. M than 30 g/L and less than 10% bone marrow clonal plasma cells with no evidence of other B-cell lymphoproliferative disorder and no symptoms or organ or tissue impairment attributable to the monoclonal gammopathy (Table 1).1,3,4 The transformation rate is about 1% per year with an actuarial probability of malignant evolution at 25 years of follow-up of 30%. When the different causes of death are considered, the actual probability of malignant transformation at 25 years of follow-up is only 11%, much lower than the actuarial prediction.5 The main factors predicting progression are: the M-protein size, IgA-type and abnormal free light chain ratio,6 It is the authors’s experience the so-called evolving type (rising M-protein during the first years of follow-up) is the most important predictor for malignant evolution.7 When the monoclonal protein and the proportion of bone marrow plasma cells are consistent with MGUS but the patient has a nephrotic syndrome, congestive heart failure, peripheral neuropathy, orthostatic hypotension or massive hepatomegaly the most likely diagnosis is primary systemic amyloidosis resulting from the deposition of amyloidogenic light chains.4 In a patient with constitutional symptoms, lytic bone lesions, a small M-spike and less than 10% plasma cells in the bone marrow, the most likely diagnosis is metastatic carcinoma with a coincidental MGUS. Smoldering multiple myeloma Classification and diagnosis The criteria for classification and diagnosis of monoclonal gammopathies has been reviewed by the International Myeloma Working Group.1 Monoclonal gammopathy of undetermined significance MGUS has a high prevalence (3.2 and 5.8 percent in people over 50 and 70 years of age respectively).2 It is characterized by the presence of a serum M-protein lower | 102 | The term smoldering multiple myeloma was clearly defined by Kyle and Greipp as the presence of a serum M-protein higher than 30 g/L and a proportion of bone marrow plasma cells equal or greater than 10% in the absence of lytic bone lesions or clinical manifestations due to the monoclonal gammopathy.8 More recently, the International Myeloma Working Group considered that the term asymptomatic myeloma might be more appropriate than smoldering multiple myeloma. This condition Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 1. Monoclonal gammopathy of undetermined significance (MGUS). higher and all patients will eventually evolve into a symptomatic MM.9-14 Serum M-protein < 30 g/L Symptomatic multiple myeloma Bone marrow clonal plasma cells < 10% The diagnosis of symptomatic MM requires the presence of an M-protein in serum and/or urine, increased plasma cells in the bone marrow or plasmacytoma, and related organ or tissue impairment (including bone lesions). The more common symptoms are weakness and fatigue from anemia and bone pain due to the skeletal involvement. Some patients may have no symptoms but have related organ or tissue impairment. Clinical features may include anemia, skeletal involvement (lytic lesions and/or severe osteoporosis with or without compression fractures), renal failure, hypercalcemia, recurrent bacterial infections, extramedullary plasmacytomas, hiperviscosity (very rare) or associated amyloidosis (Table 3). The criteria agreed by the International Myeloma Working Group for the diagnosis of symptomatic MM are depicted in Table 4.1 Note that no serum or urine M-protein levels were included. About 40% of patients with symptomatic MM have a serum M-protein lower than 30 g/L and 3% have non-secretory MM (see Table 5 for the diagnostic criteria of non-secretory). Also, no minimal proportion of bone marrow plasma cells was required, since about 5% of patients with symptomatic MM have less than 10% plasma cells in the bone marrow. In fact, the most critical criterion for disease requiring cytotoxic therapy is the evidence of organ or tissue impairment (end organ damage) manifested by the clinical features mentioned above. The criteria for solitary plasmacytoma of bone and extramedullary plasmacytoma are shown in Tables 6 and 7 respectively.1 Plasma cell leukemia is an aggressive variant of MM defined by a peripheral blood absolute plasma cell number of at least 2×109/L and more than 20% plasma cells in the peripheral blood differential white cell count.1 Plasma cell leukemia is classified as primary when it presents in the leukemic phase (60% of cases) or as secondary when it results from the transformation of a previously recognized MM. No evidence of other B-cell proliferative disorders No related organ or tissue impairment Table 2. Asymptomatic myeloma (smouldering myeloma). Serum M-protein ≥30 g/L or urine light chain ≥1g/24h or Bone marrow clonal plasma cells ≥10% No related organ or tissue impairment (no end organ damage including bone lesions) or symptoms. Table 3. Myeloma-related organ or tissue impairment (end organ damage) (ROTI) due to the plasma cell proliferative process. Increased serum Calcium Renal insufficiency Anemia: hemoglobin 2 g/dL below the lowest normal limit Bone lesions: lytic lesions or osteoporosis with compression fractures (possibly confirmed by MRI or CT) Other: symptomatic hyperviscosity (rare), amyloidosis, recurrent bacterial infections (> episodes in 12 months), extramedullary plasmacytomas. CRAB (calcium, renal insufficiency, anemia or bone lesions). Table 4. Symptomatic multiple myeloma*. M-protein in serum and /or urine Bone marrow (clonal) plasma cells or plasmacytoma** Related organ or tissue impairment (end organ damage, including bone lesions) * Some patients may have no symptoms but have related organ or tissue impairment; ** If flow cytometry is performed, most plasma cells (>90%) will show a “neoplastic” phenotype. Table 5. Non-secretory myeloma. No M-protein in serum and/or urine with negative immunofixation* Bone marrow clonal plasmacytosis ≥ 10% or plasmacytoma Related organ or tissue impairment (end organ damage, including bone lesions) *Oligosecretory: urine light chain excretion < 200 mg/24hrs (usually of kappa type). was defined as the presence of an M-protein equal or higher than 30 g/L and/or ≥10% bone marrow plasma cells in the absence of symptoms or organ or tissue impairment due to the monoclonal gammopathy1 (Table 2). About 10% of patients diagnosed with MM have smoldering disease.9,10 This situation is clinically and biologically very close to that observed in MGUS. However, the plasma cell mass is much Prognostic factors and staging systems The median survival of patients with MM is about 3 years. However, survival varies from one patient to another. While some patients die within the first few months from diagnosis others survive for more than 5 and even for more than 10 years. This variability in survival relates mainly to prognostic factors associated with certain characteristics of both the host and the tumor. Since the first report in 1967 by Carbone et al.,15 many studies on prognostic factors have been published resulting in the identification of a large Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 103 | 12th Congress of the European Hematology Association Table 6. Solitary plasmacytoma of bone. No M-protein in serum and/or urine* Single area of bone destruction due to plasma cell involvement Bone marrow not consistent with multiple myeloma Normal skeletal survey (and MRI of spine and pelvis if performed) No related organ or tissue impairment (no end organ damage other than solitary bone lesion) *A small M-component may sometimes be present. Table 7. Extramedullary plasmacytoma. No M-protein in serum and/or urine* Extramedullary tumour of clonal plasma cells Normal skeletal survey No related organ or tissue impairment (end organ damage including bone lesions) *A small M-component may sometimes be present. Table 8. Cytogenetic prognostic subgroups in multiple myeloma. Good/average prognosis Hyperdiploidy t(11;14)(q32;q32): cyclin D1 upregulation Bad prognosis Hypodiploidy t(4 ;14)(p16.3 ;q32) : FGFR3 & MMSET upregulation t(14 ;16)(q32 ;q23) : c-MAF upregulation Chromosome 13 deletion Chromosome 1 abnormalities : 1q gains, 1p losses number of features with prognostic impact. In this review we will consider: 1) host factors, 2) factors related to the malignant clone, and 3) factors associated with tumor mass and disease complications. We will also review the different staging systems developed for MM, with particular emphasis on the International Staging System (ISS) as well as the impact of response to therapy on long-term outcome. Host factors Age is an important prognostic factor in MM. Thus, the median survival of patients younger than 40 and 30 years was 54 and 87 months respectively.16,17 In contrast, the median survival of patients over 70 years was only 23 months.18 Another critical prognostic feature is the performance status (PS) at the time of diagnosis. In fact, patients with a PS greater than 2 have a significantly poorer survival compared with those with a lower PS.19 Factors related to the malignant clone In the Mayo Clinic experience, plasmablastic morphology is an important prognostic feature.20 However, plasma cell proliferative status, measured either by plasma cell labelling index or by flow cytometry, is one of the most reliable prognostic indicators in patients with MM.21 Cytogenetic status has emerged as the most important prognostic factor in MM. As shown in Table 8, patients with hyperdiploidy have a good outcome in contrast with those with hypodiploidy, and patients with t(11;14) have an average survival. The cytogenetic poor prognostic features are: retinoblastoma (RB) and P53 deletions and immunoglobulin heavyheavy chain (IgH) translocations, mainly the t(4;14) and t(14;16).22 Although RB deletions have emerged as an important prognostic indicator in many studies, the coexistence of RB deletions with IgH translocations has raised the question of whether the prognostic impact of each abnormality may be influenced by the other. In considearation of this, the Spanish Myeloma Group has just reported that in a multivariate analysis that the only features independently affecting survival were t(4;14), RB deletion associated with other cytogenetic abnormalities, age > 60 years, high proportion of S-phase cells and the advanced disease stage according to the ISS.23Thus, RB deletion as single cytogenetic abnormality would not have a negative prognostic impact while t(4;14) is the worst prognostic feature. On the other hand, gains in chromosome 1 is one of the more frequent cytogenetic findings in patients with MM. The up-regulation of 1q genes as well as the down-regulation of 1p genes is a poor prognostic feature.24 Thus, gene expression profiling studies have shown that the high expression of the gene CKS1B (located in 1q21) is a marker of very short survival. Thus, a high expression of CKS1B, plus other cytogenetic abnormalities excluding t(11;14), define a poor prognosis population even in patients undergoing a tandem transplant approach.24 Prognostic factors associated with plasma cell mass and disease complications The most important prognostic marker in MM is beta2-microglobulin.25 Its serum levels are related to both the plasma cell mass and the renal filtering capacity. Its value has been reproduced in many studies and has been successfully included in many staging systems (see below). It must be emphasized that its measurement is only useful at the time of diagnosis and not for disease monitoring during follow-up. The hemoglobin level, and in some series a low platelet count, resulting from bone marrow involvement by plasma cells is an important prognostic factor. The presence of circulating plasma cells, identified either by morphology or immunophenotyping, is associated with advanced disease and is an independent prognostic factor.26 Renal function impair- | 104 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 9. Main staging systems in multiple myeloma. Author, year Durie and Salmon, 1975 Merlini et al., 1980 MRC, 1980 Parameters Other Hb, Ca, M-protein, bone lesions Renal function %PC, Cr, and Ca (IgG) Hb, Ca, M-protein (IgA) Hb, urea, PS than 11,000 patients included in cooperative studies and from large individual institutions.37 The ISS is based on the serum levels of beta2-microglobulin and albumin. It defines three risk groups with median survival of 62, 44 and 29 months respectively. Importantly, this classification was reproduced in all age groups, in patients with different geographic origins, and in patients treated with standard dose therapy as well as those undergoing autologous transplantation. Cavo et al., 1989 D & S, platelet count Greipp et al., 1988 β2-microglobulin, LI Bladé et al., 1989 Albumin, urea Response to therapy as prognostic factor San Miguel et al., 1989 Hb, Cr, PS, PI San Miguel et al.,1995 S-phase, β2-microglobulin, age, PS Before the introduction of novel drugs, few patients treated with conventional chemotherapy achieved CR and the correlation between the degree of tumor response and survival was the subject of debate.38 In fact, in many studies, the stabilization of tumor burden was a more powerful prognostic indicator than the degree of tumor reduction.38-42 In contrast with the low CR rate attained with conventional chemotherapy, between 35 and 50 percent of patients enter CR after highdose therapy/stem cell support (HDT/SCT).43-45 A correlation between the degree of response and survival has been shown after HDT/SCT.43,44-47 So patients entering CR post-transplant have a significantly longer EFS and OS than those who enter in PR or do not respond.46-48 This would suggest that there is a difference in the quality of CR after conventional chemotherapy and after HDT/SCT. However, in the MD Anderson experience, the EFS and OS survival of patients achieving CR was similar irrespective of whether the CR was achieved with conventional or with HDT/SCT.46,48 This thus raises the question of whether patients already in CR with primary therapy gain benefit from highdose intensification. With the incorporation of novel therapies (thalidomide, bortezomib, lenalidomide) in the primary therapy, up the one-third of patients with MM achieve CR.49-52 A longer followup is needed to establish the impact of these CR on PFS and OS and to evaluate how far the increased tumor reduction with initial chemotherapy can represent a real influence on the long-term outcome of patients undergoing HDT/SCT intensification. IMWG, 2005 β2-microglobulin, albumin MRC, Medical Research Council; IMWG, International Myeloma Working Group; Hb, haemoglobin; Ca, calcium; PC, plasma cells; Cr, creatinine; Ig, Immunoglobulin; PS, performance status; LI, labeling index; PI, paraprotein index. ment due to tubular damage by nephrotoxic light chains is one of the most adverse prognostic indicators.27,28 In the overall series, the median survival of patients with renal failure is less than 1 year. The reversibility rate of renal failure in patients with MM ranges from 20% to 60%.27,28 The survival of patients with reversible renal failure is similar to the survival of patients with initial normal renal function. In the author’s experience, the factors associated with renal function recovery are a serum creatinine level lower than 4 mg/dL, a 24-hour urine protein excretion lower than 1 g, and a serum calcium level higher than 11.5 mg/dL.28 Staging systems for multiple myeloma A number of prognostic classification systems for MM have been developed during the last 30 years (see Table 9). These staging systems are usually based on prognostic factors derived from multivariate regression models. The most widely used classification was proposed by Durie and Salmon in 1975.29 Based on a mathematical model to assess tumor cell mass, three stages based on the four parameters showing a higher correlation with the number of plasma cells (M-protein size, hemoglobin, calcium, and extent of bone disease) were established. Each stage was subclassified as A or B according to renal function status. Despite the widespread use of the Durie and Salmon staging system, there has been no universal agreement on its prognostic value. Unfortunately, neither have other proposed systems been entirely satisfactory.30-36 In the search for a more useful and reproducible prognostic classification, the International Myeloma Working Group has recently developed the so-called International Staging System (ISS) derived from a total of more Criteria of response First response criteria Response criteria were first developed by the Chronic Leukemia and Myeloma Task Force (CLMTF) in 1968 and were reviewed by the same group in 1973.53 The main response parameter was a an minimum 50% a reduction in the M-protein. In 1972, the Southwest Cancer Chemotherapy Study Group, now the Southwest Oncology Group (SWOG), defined partial response as a reduction of at Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 105 | 12th Congress of the European Hematology Association Table 10. International uniform response criteria for multiple myeloma. Response Category* Criteria CR Negative IF (serum and urine) 5% BMPC No soft tissue plasmacytomas sCR As above plus Normal FLC ratio Absence of clonal plasma cells** VGPR ≥90% serum M-protein ⇓ Urine M-protein < 100 mg/24h PR ≥50% serum M-protein ⇓ ≥90% urine M-protein ⇓ or < 200 mg/24hrs ≥50% ⇓ soft tissue plasmacytomas *All response categories require two consecutive measurements made at any time; ** Determined by immunohistochemistry or immunofluorescence; CR, complete remission; sCR, stringent complete remission; VGPR, very good partial response; PR, partial response; IF, immunofixation; BMPC, bone marrow plasma cells; FLC, free-light chain. least 75% in the calculated serum paraprotein synthetic rate and/or a decrease of at least 90% in urinary light chain urine protein excretion sustained for at least two months.54 The CLMTF or SWOG criteria were used in most clinical trials, although modifications to the original proposals were frequently made. An exception to the above criteria was the Medical Research Council Myelomatosis trials, in which response was evaluated by the proportion of patients achieving the so-called plateau phase.This phase consists of a period of stability after chemotherapy in which tumor progression does not occur despite the persistence of measurable disease. The minimum period of stability required to define plateau was 3 months.55 Since complete remissions (CR) were rarely observed with the old conventional dose chemotherapy, neither the CLMTF nor the SWOG response criteria included a definition of CR. In addition, there was no definition for disease progression or relapse. The EBMT, IBMTR and ABMTR criteria for response, relapse and progression With the introduction of high-dose therapy/stem cell transplantation, the M-protein has disappeared in a significant number of patients, ans is therefore associated with a significant survival prolongation. In this context, the EBMT developed new criteria defining CR (negative inmunofixation in serum and urine in the absence of increased plasma cell in the bone marrow), partial response (PR), minimal response (MR), as well as criteria for relapse (reappearance of the M-protein in patients who had achieved CR), and progression from PR or MR.56 It is important that any type of response should be maintained for a minimum of six weeks. These criteria have been used over recent years in both transplant and in non-transplant series as well as in prospective phase II and III clinical trials, and have been shown to be useful and reproducible. The international uniform response criteria for multiple myeloma The International Myeloma Working Group has expanded the EBMT criteria and categories for stringent CR and very good partial response have been added.57 Also, the serum free light chain measurements have been included for the definition of stringent CR and for the evaluation of response in patients with non-secretory or oligosecretory disease (Table 10). All response categories require two consecutive assessments at any time in contrast to the EBMT which required an interval of at least six weeks between the two measurements for response confirmation. In addition, the time to event, duration of response, clinical relapse and time to alternative treatment are emphasized as critical end points.57 References 1. The International Myeloma Working Group. Criteria for the classification of monoclonal gammopathies, multiple myeloma and related disorders: a report of the International Myeloma Working Group. Br J Haematol 2003;121:49-57. 2. Kyle RA, Therneau TM, Rajkumar SV, et al. Prevalence of monoclonal gammopathy of undetermined significance. N Engl J Med 2006;354:1362-9. 3. Kyle RA. Monoclonal gammopathy of undetermined significance: natural history in 241 cases. Am J Med 1978;64:814-26. 4. Bladé J. Monoclonal gammopathy of undetermined significance. N Engl J Med 2006;355:2765-70. 5. Kyle RA, Therneau TM, Rajkumar SV, et al. Long-term study of prognosis in monoclonal gammopathy of undetermined significance. N Engl J Med 2002;346:564-569. 6. Rajkumar SV, Kyle RA, Therneau TM, et al. Serum free light chain ratio is an independent risk factor for progression in monoclonal gammopathy of undetermined significance. Blood 2005;106:812-817. 7. Rosiñol L, Cibeira MT, Montoto S, et al. Monoclonal gammopathy of undetermined significance: predictors of malignant transformation and recognition of an evolving type characterized by a rising M-protein. Mayo Clin Proc 2007 (in press). 8. Kyle RA, Greipp PR. Smoldering multiple myeloma. N Engl J Med 1980;302:1347-9. 9. Rosiñol L, Bladé J, Esteve J, et al. Smoldering multiple myeloma: natural history and recognition of an evolving type. Br J Haematol 2003;123:631-6. 10. Wisloff F, Andersen P, Andersson TR. Incidence and follow-up of asymptomatic multiple myeloma. Eur J Haematol 1991;47:338-341. 11. Alexanian R, Barlogie B, Dixon D. Prognosis of asymptomatic multiple myeloma. Arch Intern Med 1988;148:1963-5. 12. Dimopoulos M, Moulopoulos L, Smith T, Delasalle K, Alexanian R. Risk of disease progression in asymptomatic multiple myeloma. Am J Med 1993;94:57-61. 13. Weber D, Dimopoulos M, Moulopoulos L, Delasalle E, Smith T, Alexanian R. Prognostic features of asymptomatic multiple myeloma. Br J Haematol 1997;97:810-4. 14. Facon T, Menard JF, Michaux JL, et al. Prognostic factors in low tumor mass asymptomatic multiple myeloma: a report on 91 | 106 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 patients. Am J Haematol 1995;48:71-5. 15. Carbone PP, Kellerhouse LE, Gehan EA. Plasmacytic myeloma. A study of the relationship of survival to various clinical manifestations and anomalous protein type in 112 patients. Am J Med 1967;42:937-48. 16. Bladé J, Kyle RA, Greipp PR. Presenting features and prognosis in 72 patients with multiple myeloma who were younger than 40 years. Br J Haematol 1996;93:345-51. 17. Bladé J, Kyle RA, Greipp PR. Multiple myeloma in patients younger than than 30 years. Report of 10 cases and review of the literature. Arch Intern Med 1996;156:1463-8. 18. Bladé J, Muñoz M, Fontanillas M, et al. Treatment of multiple myeloma in elderly people: long-term results in 178 patients. Age and Ageing 1996;25:357-61. 19. San Miguel JF, Fonseca R, Greipp PR. Prognostic factors and classification for multiple myeloma: contribution to clinical management. In: Myeloma. Biology and Management. Malpas JS, Bergsadel DE, Kyle RA, Anderson KC, Eds. Third Ed. Saunders, Elsevier Inc, Oxford, 2004;pp:189-99. 20. Greipp PR, Raymond NM, Kyle RA, O`Fallon WM. Multiple myeloma: significance of plasmablastic subtype in morphological classification. Blood 1985;65:305-10. 21. Greipp PR, Witzig TE, Gonchoroff NJ, et al. Immunofluorescence labeling indeces in myeloma an related monoclonal gammopathies. Mayo Clin Proc 1987;62:969-77. 22. Fonseca R. Cytogenetics in multiple myeloma. In: Myeloma. Biology and Management. Malpas JS, Bergsagel DE, Kyle RA, Anderson KC, Eds. Third Ed. Saunders, Elsevier Inc, Oxford, 2004, pp:67-81. 23. Gutiérrez NC, Castellanos MV, Martin ML, et al. Prognostic and biological implications of genetic abnormalities in multiple myeloma undergoing autologous stem cell transplantation: t(4;14) is the most relevant adverse prognostic factor, whereas RB deletion as a unique abnormality is not associated with adverse prognosis. Leukemia 2007;21:143-50. 24. Shaughnessy JD, Zhan F, Burington B, et al. A validated gene expression signature of high-risk multiple myeloma is defined by disregulated expression of genes mapping chromosome 1. Blood 2006;108:37a (Abstract 111). 25. Bataille R, Grenier J, Sany J. Beta2-microglobulin in myeloma. Optimal use for sataging, prognosis and treatment: a prospective study of 160 patients. Blood 1984;63:468-76. 26. Witzig TE, Gertz MA, Lust JA, Byle RA, O’Fallon W, Greipp PR. Peripheral blood monoclonal plasma cells as a predictor of survival in patients with multiple. Blood 1996;88: 1780-1787. 27. Alexanian R, Barlogie B, Dixon D. Renal failure in multiple myeloma: pathogenesis and prognostic implications. Arch Intern Med 1990;150:1693-5. 28. Bladé J, Fernández-Llama P, Bosch F, et al. Renal failure in multiple myeloma. Presenting features and predictors of outcome in 94 patients from a single institution. Arch Intern Med 1998;158:1889-93. 29. Durie BGM, Salmon SE. A clinical staging system for multiple myeloma. Correlation of myeloma cell mass with presenting clinical features, response to treatment, and survival. Cancer 1975;36:842-54. 30. Merlini G, Waldenström JG, Jayakar SD. A new improved clinical staging system for multiple myeloma based on analysis of 123 treated patients. Blood 1980;55:1011-9. 31. Medical research Council’s Working Party on Leukemia in Adults. Prognostic features on the third MRC myelomatosis trial. Br J Cancer 1980;42:831-40. 32. Cavo M, Galieni P, Zuffa E, Baccarani M, Gobbi M, Tura S. Prognostic variables and clinical staging in multiple myeloma. Blood 1989;74:1778-80. 33. Greipp PR, Katzmann JA, O’Fallo WM, Kyle RA. Value of beta2-microglobulin and plasma cell labeling indeces as prognostic factors in patients with newly diagnosed myeloma. Blood 1988;72:219-23. 34. Bladé J, Rozman C, Cervantes F, Reverter JC, Montserrat E. A new prognostic system for multiple myeloma based on easily available parameters. Br J Haematol 1989;72:507-511. 35. San Miguel JF, Sánchez I, González M. Prognostic factors and classification in multiple myeloma. Br J Cancer 1989;59:11318. 36. San Miguel JF, García Sanz R, González M, et al. A new staging system for multiple myeloma based on the number of Sphase plasma cells. Blood 1995;85:448-55. 37. Greipp PR, San Miguel J, Durie BG, Crowley JJ, Barlogie B, Blade J, et al. International staging system for multiple myeloma.J Clin Oncol 2005;23:3412-20. 38. Bladé J, López-Guillermo A, Bosch F, et al. Impact of response to treatment on survival in multiple myeloma: results in a series of 243 patients. Br J Haematol 1994;88:117-21. 39. Palmer M, Belch A, Brox L, Pollock E, Koch M. Are the current criteria for response useful in the management of multiple myeloma. J Clin Oncol 1987;5:1373-7. 40. Marmont F, Levis A, Falda M, Resegotti L. Lack of correlation between objective response and death rate in multiple myeloma patients treated with oral melphalan and prednisone. Ann Oncol 1991;2:191-5. 41. Oivanen TM, Kellokumpu-Lehtinen P, Koivisto AM, Koivunen E, Palva I. Response level and survival after conventional chemotherapy for multiple myeloma: a Finnish Leukemia Group study. Eur J Haematol 1999;62:109-16. 42. Durie BGM, Jacobson J, Barlogie B, Crowley J. Magnitude of response with myeloma frontline therapy does not predict outcome: importance of time to progression in Southwest Oncology Group chemotherapy trials. J Clin Oncol 2004;22:1857-63. 43. Attal M, Harousseau JL, Stoppa AM, et al. A prospective, randomized trial of autologous bone marrow transplantation and chemotherapy in multiple myeloma. Intergroup Francais du Myelome. N Engl J Med 1996;335:91-7. 44. Child JA. Morgan GJ, Davies FE, et al. High-dose chemotherapy with hematopoietic stem-cell rescue for multiple myeloma. N Engl J Med 2003;348:1875-83. 45. Lahuerta JJ, Martínez-López J, de la Serna J, et al. Remission status by immunofixation vs. electrophoresis after autologous transplantation has a major impact on the outcome of multiple myeloma patients. Br J Haematol 2000;109:438-46. 46. Alexanian R, Weber D, Giralt S, et al. Impact of complete remission with intensive therapy in patients with responsive multiple myeloma. Bone Marrow Transpl 2001;27:1037-43. 47. Bladé J, Esteve J, Rives S, et al. High-dose therapy autotransplantation/ intensification vs continued standard chemotherapy in multiple myeloma in first remission. Results of a nonrandomized study from a single institution. Bone Marrow Transpl 2000;26:845-9. 48. Wang M, Delasalle K, Thomas S, Giralt S, Alexanian R. Complete remission represents the major surrogate marker of long survival in multiple myeloma. Blood 2006;108:123a (Abstract 403). 49. Facon T, Mary JY, Hulin C, et al. Major superiority of melphalan-prednisone (MP) plus thalidomide (THAL) over MP and autologous stem cell transplantation in the treatment of newly diagnosed elderly patients with multiple myeloma. Blood 2005;106 (Abstract 780). 50. Palumbo A, Bringhen S, Caravita T, et al. Oral melphalan and prednisone chemotherapy plus thalidomide compared with melphalan and prednisone alone in elderly patients with multiple myeloma: randomised controlled trial. Lancet 2006;367:825-31. 51. Mateos MV, Hernández JM, Hernández MT, et al. Bortezomib plus melphalan and prednisone in elderly untreated patients with multiple myeloma: results of a multicenter phase 1/2 study. Blood 2006;108:2165-72. 52. Palumbo A, Falco P, Falcone A, et al. Oral Revlimid plus melphalan and prednisone (R-MP) for newly diagnosed multiple myeloma: results of a multicenter phase I/II study. Blood 2006;108:240a (Abstract 800). 53. Chronic Leukemia-Myeloma Task Force. National Cancer Institute. Proposed guidelines for protocol studies. II. Plasma cell myeloma. Cancer Chemother Reports 1973;4:145-58. 54. Alexanian R, Bonnet J, Gehan E, et al. Combination chemotherapy for multiple myeloma. Cancer 1972;30:382-9. 55. MacLennan ICM, Chapman C, Dunn J, Kelly K. Combined chemotherapy with ABCM versus melphalan for treatment of myelomatosis. Lancet 1992;339:2000-5. 56. Bladé J, Samson D, Reece D, et al. Criteria for evaluating disease response and progression in patients with multiple myeloma treated by high-dose therapy and haematopoietic stem cell transplantation. Br J Haematol 1998;102:1115-23. 57. Durie BGM, Harousseau JL, San Miguel JF, et al. International uniform response criteria for multiple myeloma. Leukemia 2006;20:1467-73. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 107 | Myeloma Novel treatment approaches in multiple myeloma A. Palumbo1 I. Avonto1 P. Falco1 F. Cavallo1 T. Caravita2 M.T. Petrucci3 M. Cavo4 M. Boccadoro1 1 Divisione di Ematologia dell'Università di Torino, Azienda Ospedaliera S. Giovanni Battista, Torino; 2 Cattedra e Divisione di Ematologia, Università Tor Vergata, Ospedale S. Eugenio, Roma; 3 Dipartimento di Biotecnologie ed Ematologia, Università La Sapienza, Roma; 4 Istituto di Ematologia e Oncologia Medica “Seragnoli”, Università di Bologna, Italy. Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:108-114 ultiple myeloma is the second most common oncohematological disease. At diagnosis, the majority of patients are older than 65 years. About 35% of myeloma patients are aged under 65, 28% are between 6574 and 37% are over 75.1 The current changes of the European demographic curves will probably increase the incidence of elderly patients in the near future. In newly diagnosed myeloma patients under 65, high-dose melphalan followed by autologous stem cell transplantation is considered the standard of care. In elderly patients, usually over 65, oral melphalan and prednisone (MP) have been considered the standard. The recent discovery of new drugs, such as thalidomide, lenalidomide and the proteasome inhibitor bortezomib, targeting both the myeloma cells and the bone marrow microenvironment, have significantly increased the clinical efficacy of the old chemotherapy regimens. The challenge is now to define the optimal sequence and combination of these drugs to allow a significant impact on the natural history of the disease. M New induction regimens for younger patients candidates for autologous transplantation In patients younger than 65 years, melphalan 200 mg/m2 supported by autologous stem cell transplantation appears to be the treatment of choice. Several studies clearly demonstrated the superiority of melphalan 200 mg/m2 in terms of response rate and event-free survival when compared with conventional treatments. Results were less consistent when overall survival was examined.2 In a randomized study, tandem autologous transplantation improved complete response (CR) rates, prolonged event-free and overall survival in comparison with the single transplantation.3 These results were particularly evident among patients who did not have a very good partial response (VGPR) after one transplantation. The 7| 108 | year overall survival was 11% in the single-transplant group and 43% in the double-transplant group (p<0.001). Autologous transplantation is usually preceded by de-bulking chemotherapy with steroid-based regimens. High-dose dexamethasone or vincristine-doxorubicin-dexamethasone (VAD) were the most commonly used induction regimens. Recently, new drugs such as thalidomide, lenalidomide and bortezomib have been used in association with dexamethasone as induction treatment for newly diagnosed patients. In a randomized study, the combination thalidomide-dexamethasone increased partial response (PR) rate (p=0.001) and 2-year event-free survival (p<0.0001) when compared with dexamethasone alone.4 No marked survival differences were reported, although the trial was not powered for a long-term followup (Table 1). A retrospective case-control study showed superior PR rates for thalidomide-dexamethasone in comparison with standard VAD, but higher rates of deep-vein thrombosis (15%) were reported.5 In a randomized study, the combination thalidomide-dexamethasone was compared with VAD. Before stem cell collection, the VGPR rate was 24.7% vs 7.3% (p=0.0027), respectively. Six months after transplantation the VGPR rate was quite similar in both arms (44.4% vs 41.7%, p=0.87).6 Toxicity was higher in the thalidomide-dexamethasone group. Thalidomide-dexamethasone reduced the mean duration of hospitalization before stem cell collection from 20 to 8.3 days, without any negative impact on the amount of stem cell harvest. When thalidomide was incorporated into the high-dose therapy followed by autologous transplantation, a higher CR rate (62% vs 43%) and improved 5-year event-free survival (56% vs 44%) was observed compared with high-dose therapy without thalidomide.7 Unfortunately, the 5-year overall survival was similar in both groups (p=0.9). In the thalidomide Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 group, a higher rate of thromboembolism (30% vs 17%) and peripheral neuropathy (27% vs 17%) were reported (Table 1). The combination lenalidomide-dexamethasone has been evaluated in 34 newly diagnosed patients. The PR rate was 91%, including a CR plus VGPR rate of 56%. In 13 patients 4 induction cycles of lenalidomide–dexamethasone were followed by autologous transplantation. In 21 patients, the lenalidomide-dexamethasone induction regimen was delivered for a prolonged period of time without autologous transplant consolidation, and the CR plus VGPR rate was 67%. The 2-year progression-free survival was 83% in the group that received autologous transplantation and 59% in the group that received lenalidomidedexamethasone only.8 These preliminary data support the proposal to incorporate high-dose melphalan after the induction treatment of myeloma patients. Grade 3 or higher adverse events were very limited, including neutropenia, pneumonia, and cutaneous rash. Deep-vein thrombosis was only 3%, but prophylactic aspirin was introduced during treatment. A randomized phase III trial of lenalidomide plus high-dose dexamethasone versus lenalidomide plus low-dose dexamethasone (40 mg; days 1, 8, 15, and 22) has been recently reported.9 Although efficacy data were not available, the incidence of adverse events was significantly reduced in the low-dose dexamethasone arm. Early deaths were reduced from 4.5% to 1.4%; infections from 19% to 9%, and deepvein thrombosis from 18% to 5% (Table 1). Bortezomib, as single agent or in combination with dexamethasone has been studied as first-line treatment. In this trial, dexamethasone was added to bortezomib when suboptimal responses, such as less than PR after 2 cycles or less than CR after 4 cycles, were reported.10 This approach improved the suboptimal responses of bortezomib alone in 64% of patients. After the addition of dexamethasone, the PR rate was 90%, including 19% of CR and near CR. Stem cell harvest and engraftment were successful in all patients. The most common adverse events were neuropathy (37%), fatigue (20%), constipation (16%), nausea (12%) and neutropenia (12%). In a recent randomized trial, the association bortezomibdexamethasone has been compared with VAD as induction regimen before autologous transplantation.11 Bortezomib-dexamethasone significantly increased both PR rate (82% vs 67%) and VGPR plus CR rate (43% vs 26%). In the bortezomib-dexamethasone group, 78% of patients did not require a second autologous transplantation. Serious adverse events were similar in both arms. In 21 newly diagnosed patients, the combination of bortezomib, pegylated-liposomal doxorubicin and dexamethasone induced a PR rate of 95%, including 29% of CR plus nearCR.12 More frequent grade ≥3 adverse events were infections (48%), neuropathy (5%), nausea and vomiting (5%) (Table 1). New maintenance approaches Maintenance therapy has been shown to prolong response rate and event-free survival in patients who have received induction treatment. However, the role of maintenance remains controversial in myeloma. After conventional or high-dose therapy, maintenance with interferon-alpha provided marginal benefits. In patients who responded to conventional chemotherapy, maintenance therapy with 50 mg alternate-day prednisone significantly improved progression-free and overall survival in comparison with 10 mg alternate-day prednisone.13 In a large randomized study conducted by the French group, patients younger than 65 years were randomly assigned to receive no maintenance, pamidronate, or pamidronate plus thalidomide.14 The 3-year post-randomization probability of event-free survival (p<0.009) and the 4-year overall survival (p<0.04) were significantly prolonged in patients who received thalidomide. The proportion of patients who had skeletal events was not influenced by the administration of pamidronate. Grade 3-4 Table 1. New induction regimens tested in myeloma patients < 65 years of age. Diagnosis Therapy No. of patients Median age (range) ≥PR % CR Progression-free % Survival Overall Survival TD TD TD ASCT-T RD VD PAD 103 100 100 323 34 79 21 65 (38-83) 54 (49-59) 55 (ND) ND 64 (32-78) 55 (ND) 55 (37-66) 63 70 25§ ND 91 82 95 4 50% at 22 months 10 ND ND ND 62 56% at 5 years* 18 74% at 2 years 9 ND 21 ND 72% at 2 years ND ND 65% at 5 years 91% at 2 years ND ND PeripheralDVT/ Neutropenia Thrombocytopenia Infection References Neuropathy Embolism grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) 7 4 17° 27°° ND 3 5 17 15 23° 30°° 3 3 0 9 0 ND 94°° 21 ND 5 ND ND ND ND 0 ND 0 6 4 ND ND 6 4 48 4 5 6 7 8+ 11 12 ASCT-T: autologous transplant+thalidomide; CR: complete response; DVT: deep-vein thrombosis; ND: not determinate; PAD: bortezomib+doxorubicin+dexamethasone; PR: partial response; RD: lenalidomide+dexamethasone; TD: thalidomide+dexamethasone; VD: bortezomib+dexamethasone; *event-free survival; §very good partial response; °all grades; °°> grade 2; +updated information was presented at ASH 2006 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 109 | 12th Congress of the European Hematology Association Table 2. New induction regimens tested in myeloma patients > 65 years of age. Therapy Diagnosis MPT MPT MPR VMP No. of pts. 124 129 54 60 Median >65 years ≥PR CR age (range) % % ND (65-75) 72 (60-85) 71 (57-77) 75 (65-85) 100 97 96 100 81 76 85 89 16 16 24 32 Progression-free survival Overall survival PeripheralDVT/ Neutropenia Thrombocytopenia Infection References neuropathy embolism grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) 50% at 28 months 78% at 2 years 6 54% at 2 years° 80% at 3 months 8 91% at 2 years 92% at 2 years 0 91% at 16 months 90% at 16 months 17 12 12 6 ND 48 16 66 43 14 3 34 51 13 10 8 16 18+ 19 21+ 22 CR: complete response; DVT: deep-vein thrombosis; MPR: melphalan+prednisone+lenalidomide; MPT: melphalan+prednisone+thalidomide; ND: not determinate; PR: partial response; VMP: bortezomib+melphalan+prednisone; °event-free survival; +updated information was presented at ASH 2006. neuropathy (7%), fatigue (6%) and constipation (1%) were more prominent in the thalidomide group. The incidence of thromboembolic events was not significantly different in the 3 arms. More recently, a randomized trial compared thalidomide-prednisone versus prednisone alone as maintenance therapy after autologous stem cell transplantation. The 1-year progression-free survival was 91% vs 69%, and the 2year overall survival was 90% vs 81 respectively. Neurological side effects were more common with thalidomide, but no differences were observed in the incidence of thromboembolic events.15 New induction regimens for elderly patients The MP regimen has been considered the standard of care for elderly patients. In a randomized trial, 4 treatment regimens have been evaluated: MP, melphalan and dexamethasone, high-dose dexamethasone, or high-dose dexamethasone plus interferon-alpha.16 PR rates were significantly higher among patients receiving melphalan-dexamethasone. Median progression-free survival was 21 and 23 months after MP or melphalan and dexamethasone, but only 12 and 15 months after high-dose dexamethasone or high-dose dexamethasone plus interferon-alpha respectively. No difference in overall survival was reported among the 4 different groups. These data clearly show that melphalan should be incorporated in the induction regimen for elderly patients who are not candidates for autologous transplant. In patients older than 65 years, melphalan 200 mg/m2 followed by autologous transplant is too toxic, while intermediate-dose melphalan (100-140 mg/m2) seems more suitable. In the Italian study, patients were aged 65-70 years and melphalan 100 mg/m2 was superior to MP.17 In the French study, patients were aged 65-75 years and melphalan 100 mg/m2 was superior to MP in terms of response rate, but not in terms of progression-free and overall survival.18 In the first study, 22% of patients did not complete the assigned treatment and in the second trial, 37% did not complete it. According to these data, the age of 70 years might be considered the age limit for intermediate-dose melphalan. Recently, thalidomide has been added to the MP regimen (MPT). In the Italian randomized trial, oral MPT was compared with MP in patients aged 60-85 years.19 The PR rates were 76% in MPT patients and 47.6% in MP subjects. Near-CR or CR rates were 27.9% after MPT and 7.2% after MP. The 2-year event-free survival rates were 54% for MPT and 27% for MP (p=0.0006). The 3-year survival rates were 80% for MPT and 64% for MP (p=0.19). MPT was associated with a higher risk of grade 3-4 neurological adverse events compared to MP regimen (10% vs 1%), infections (10% vs 2%, p=0.001), cardiac toxicity (7% vs 4%) and thromboembolism (12% vs 2%). The introduction of enoxaparin prophylaxis significantly reduced the rate of thromboembolism from 20% to 3% (p=0.005) (Table 2). In the French phase III trial, comparing MPT with MP with intermediate-dose melphalan (100 mg/m2) followed by autologous stem cell transplantation, a higher PR rate in the MPT and in the melphalan 100 mg/m2 arms, compared with MP, was observed (81% vs 73% vs 40%, respectively).18 Similarly, the CR rates were significantly increased after MPT and autologous transplant only. Progression-free survival was superior in the MPT patients compared with both MP (p<0.001) and autologous transplantation (p=0.001). Furthermore, overall-survival was significantly improved in the MPT group in comparison with both MP (p=0.001) and autologous transplantation (p=0.004). MPT was associated with a higher risk of grade 3-4 neutropenia, infections, thrombocytopenia, thromboembolic complications, peripheral neuropathy, constipation, and cardiac events (Table 2). These data strongly support the use of MPT as standard of care in elderly patients with newly diagnosed myeloma. An increased risk of venous thromboembolism has been reported when thalidomide is combined with chemotherapy, in particular at diagnosis. The risk of venous thromboembolism is particularly high in the first 4–6 months of therapy. At diagnosis, antithrombotic prophylaxis is recom- | 110 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 mended. At present there is no evidence of the best prophylaxis. Low-molecular-weight heparin, therapeutic doses of warfarin, or daily aspirin are the preferred options.20 Lenalidomide appears to be an attractive alternative to thalidomide. In a phase I/II trial dosing, safety and efficacy of melphalan plus prednisone and lenalidomide (MPR) have been evaluated in newly diagnosed elderly myeloma patients.21 Aspirin was administered as antithrombotic prophylaxis. At the maximum tolerated dose (lenalidomide 10 mg plus melphalan 0.18 mg/kg), 85% of patients achieved at least a PR and 23.8% immunofixation negative CR. The 1-year event-free and overall survivals were 92% and 100%. In the MPT historical controls, the corresponding 1-year event-free and overall survivals were 78% and 87.4%. Grade 3-4 adverse events were mainly related to hematological toxicities (neutropenia 66%). Severe non-hematological side effects were less frequent and included febrile neutropenia (8%), cutaneous rash (10%) and thromboembolism (6%) (Table 2). Preliminary results showed that the event-free survival of patients with deletion of chromosome 13 or chromosomal translocation (4;14) was not significantly different from those who did not have show such abnormalities. By contrast, patients with high-levels of serum β2-microglobulin experienced a shorter event-free survival in comparison with those who showed low-levels of β2-microglobulin. Neutropenia and deep-vein thrombosis are the major complications with lenalidomide. The addition of aspirin markedly reduced the risk of thromboembolic events in newly diagnosed patients treated with lenalidomide in association with dexamethasone or chemotherapy. Although the optimal prophylaxis strategy has not been established, aspirin seems to be the preferred choice. The proteasome inhibitor, bortezomib, enhanced chemosensitivity and overcame chemoresistance in both preclinical and clinical studies. Bortezomib seems a rational approach to combinational regimens incorporating corticosteroids or chemotherapy agents. The Spanish cooperative group conducted a large phase I/II trial of bortezomib, melphalan, and prednisone (VMP).22 The association showed encouraging results. PR rate was 89%, including 32% immunofixation-negative CR, half of them achieved immunophenotypic remission (no detectable plasma cells at 10-4 to 10-5 sensitivity). The progression-free survival at 16 months of VMP patients was significantly prolonged in comparison with historical controls treated with MP only (91% versus 66%). Similarly overall survival at 16 months was improved (90% versus 62%). Interestingly, response rate, progression-free and overall survivals were similar among patients with or without retinoblastoma gene deletion or IgH translocations. These data showed that VMP overcome the poor prognosis induced by such chromosomal abnormalities. Grade 3-4 adverse events were thrombocytopenia, neutropenia, peripheral neuropathy, infections and diarrhea. (Table 2) The treatment appeared more toxic in patients older than 75 years and during early cycles. Bortezomib may induce transient thrombocytopenia and peripheral neuropathy. Pre-existing neuropathy or previous neurotoxic therapy increases the risk of peripheral neuropathy, which can be reduced or resolved by timely dose-adjustment of the drug. Bortezomib may enhance the incidence of infections, in particular Herpes Zoster reactivation, and prophylactic antiviral medication is highly recommended. New salvage combinations The majority of the combinational approaches have been studied in patients with relapsed-refractory myeloma. The thalidomide-dexamethasone combination23,24 induced a PR rate of 41-55%, and the 1year progression-free survival was around 50% (Table 3). More than 50% of patients showed constipation, somnolence and peripheral neuropathy. Thromboembolism was 7% and no antithrombotic prophylaxis was performed. The association of thalidomide with chemotherapy further increased response rates. In relapsed-refractory patients the combination of thalidomide, dexamethasone and pegylated-liposomal doxorubicin induced a CR rate of 26%, and a 22-month progression-free survival of 50%.25 Grade 3-4 neutropenia was low, but a higher rate of infections and thromboembolic events was noticed. Similar response rates were reported with the oral combination cyclophosphamide-thalidomide-dexamethasone:26 PR rate was 57% and the 2year progression-free survival was 57%. The major adverse events included constipation (24%) infections (13%) and thromboembolic toxicity (7%). In previously treated patients, lenalidomide has been combined with both steroids and chemotherapy. In two independent phase III randomized trials, the combination of lenalidomide-dexamethasone significantly increased the PR rate (59% and 58%) in comparison with dexamethasone alone (21% and 22%, p< 0.001). Similarly, the 1-year progression-free (p<0.001) and overall survival (p<0.03) were significantly improved in the lenalidomide-dexamethasone groups.27,28 These results were unchanged in the subgroup of patients older than 65 years and in those who received previous thalidomide treatment. Grade 3-4 neutropenia (16.5%) as well as thromboembolism (8.5%) were more frequent in the lenalidomide-dexamethasone group. Other side effects were reported in similar frequencies in both arms. In 62 refractory patients, lenalidomide, pegylated-liposo- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 111 | 12th Congress of the European Hematology Association Table 3. New salvage combinations. Therapy Relapsed TD Refractory TD TAD CTD RD RD RAD CRD V VDoxo VCP VMPT No. Median >65 years ≥PR CR of patients age (range) % % 77 44 50 71 177 176 62 18 333 323 27 30 65 (ND) 67 (38-87) 68 (41-82) ND 64 (33-86) 63 (33-84) 62 (57-70) 60 (34-76) 62 (48-74) 61(ND) 59 (48-74) 66 (38-79) 50 21* 44* 65 ND ND ND ND ND ND ND 57 41 55 76 57 59 58 75 70 38 48 93 67 3** 0 26 2 13 13 15 6 6 14** 43** 17 Progression-free Survival Overall Survival PeripheralDVT/ Neutropenia Thrombocytopenia Infection References Neuropathy Embolism grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) grade 3-4 (%) 50% at 1 year ND 50% at 4 months 50% at 1 year 50% at 22 months 64% at 2 years 57% at 2 yeras 66% at 2 yeras 50% at 11 months 50% at 29 months 50% at 15 months 50% at 22 months 50% at 1 year 51% at 2 years ND ND 50% at 6 months 80% at 1 year 50% at 9 months 86% at 16 months 47% at 11 year 83% at 1 year 61% at 1 year 84% at 1 year 17^ 23^ 2 6## ND ND 5 0 8 4 7°° 7 0 7^ 12 7 15 8 9 11 ND 1 0 0 5^ 9^ 16 10° 24 16 32 44 14 30 ND 43 4^ 0 2 0 12 10 13 ND 30 22 4 33 5^ ND 16 7° ND ND 13 22 13^^ 3 48 16 23 24 25 26 27+ 28+ 29 30+ 31 33+ 34 35 CR: complete response; CRD: cyclophosphamide+lenalidomide+dexamethasone; CDT: cyclophosphamide+dexamethasone+thalidomide; DVT: deep-vein thrombosis; ND: not determinate; PR: partial response; RAD: lenalidomide+ pegylated lyposomal doxorubicin+dexamethasone; RD: lenalidomide+dexamethasone; TAD: thalidomide+ pegylated lyposomal doxorubicin+dexamethasone; TD: thalidomide+dexamethasone; V: bortezomib; VCP: bortezomib+cyclophosphamide+prednisone; VDoxo: bortezomib+pegylated lyposomal doxorubicin; VMPT: bortezomib+melphalan+prednisone+thalidomide; * >70 years; **CR+nCR; ^WHO all grade; ^^ Herpes Zoster infections; #OMS score; ##OMS score>2; °°grade>2; +updated information was presented at ASH 2006. mal doxorubicin and dexamethasone showed a PR rate of 75%, including a CR rate of 15% and the 1year progression-free survival was 50%.29 The most common grade 3-4 adverse events were neutropenia (32%), thrombocytopenia (13%), infections (13%), gastrointestinal events (12%) and thromboembolism (9%) despite aspirin prophylaxis. High responses were also observed with the association of oral lenalidomide, cyclophosphamide and dexamethasone. The PR rate was 70%, including 6% CR, but grade 4 neutropenia, neutropenic fever and deep-vein thrombosis were observed (Table 3).30 Bortezomib has been effectively used alone or in combination with steroids or chemotherapy to treat relapsed-refractory myeloma patients. In the randomized phase III APEX study, 669 relapsed patients received bortezomib or oral dexamethasone.31 The response rate was significantly superior in the bortezomib arm compared with the dexamethasone arm (PR 38% versus 18%; CR 6% vs 1% respectively). Similarly, duration of response, 1-year progressionfree and 1-year survival of the bortezomib group were significantly increased. Serious adverse events included peripheral neuropathy, thrombocytopenia and gastrointestinal disorder in the bortezomib arm; psychotic disorder and hyperglycemia in the dexamethasone arm (Table 3). A recent update of this trial, confirmed the higher response rate and longer survival of the bortezomib group, even if dexamethasone-resistant patients in the control arm were allowed to crossover to receive bortezomib. Jagannath et al. recently analyzed the impact of chromosomal abnormalities on response rate and survival after treatment with bortezomib.32 Matched-pairs analysis demonstrated that borte- zomib overcomes the negative impact of chromosome 13 deletion as an independent prognostic factor, both responses and survival appeared comparable in bortezomib-treated patients with or without chromosome 13 deletion. In advanced myeloma, the association of bortezomib-doxorubicin has been compared with bortezomib alone.33 Bortezomibdoxorubicin significantly improved time to progression even in those patients previously treated with thalidomide or doxorubicin or in patients with unfavourable cytogenetic markers. Another combination of bortezomib-cyclophosphamide-prednisone proved to be very effective with a high PR rate of 93%, including 43% of CR or near CR.34 Most frequent adverse events were infections. The synergistic activity showed by bortezomib with thalidomide or melphalan provided the rationale to combine bortezomib, melphalan, prednisone and thalidomide (50 mg/day).35 In relapsed-refractory patients, the PR rate was 67%, including 17% CR. The 1-year progression-free survival was 61%, and the 1-year survival from study entry was 84%. Patients treated in the earlier phases of disease (first relapse) achieved a higher PR rate of 78%, including 36% CR. The most common grade 3 adverse events were hematologic toxicity (56%), infections (9%), Herpes Zoster reactivation (7%) and peripheral neuropathy (7%) (Table 3). Conclusions High-dose melphalan followed by autologous stem cell transplantation in the younger patients and oral melphalan-prednisone in the elderly have been considered the standard of care for the initial therapy of myeloma. | 112 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Figure 1. A proposed treatment algorithm using novel agents, according to Level of Evidence Ib based on >1 randomized controlled trial. *Thalidomide as maintenance was evaluated in patients who have not received any previous thalidomide therapy. Abbreviations: ASCT, autologous stem cell transplantation; DEX, dexamethasone; DOXO, doxorubicin; MEL200, Melphalan 200 mg/m2; MPT, melphalan plus prednisone plus thalidomide; REV, Lenalidomide; THAL, thalidomide; VEL, bortezomib Survival after transplant appears to be related to the achievement of CR or VGPR.3,7,36 An improved response rate after induction treatment, prior to transplant, could translate into better results after high-dose therapy and into a prolonged survival. In younger patients, combinations incorporating thalidomide or lenalidomide or bortezomib with dexamethasone or doxorubicin significantly increase the pre-transplant CR rate before high-dose melphalan and autologous transplantation. These combinations might further improve the CR rate achieved after transplant. Based on the data available, the combination of thalidomide and dexamethasone is recommended as induction treatment in younger patients. Further randomized prospective trials are needed to definitively assess the role of bortezomib and lenalidomide combinations and their impact on remission duration in newly diagnosed patients. Based on the French randomized study, thalidomide could also be suggested as optimal maintenance treatment after autologous stem cell transplantation. In elderly patients, the MPT combination has been shown to achieve more rapid and higher response rates and, most significantly, achieved improved event-free survival compared with conventional MP in two independent randomized trials.18,19 The MPT regimen is now recommended as the new standard of care for the elderly and for patients who are not candidates for high-dose chemotherapy with stem cell support. Other regimens such as MPR21 or VMP22 are currently under investigation and might be introduced in the clinical practice in the near future. Whether a sequential single agent treatment would yield similar survival benefits with less toxicity in comparison with a more complex combinational regimen administered at diagnosis remains an unanswered question. If a combinational approach is superior to single agent therapy, it should be considered at diagnosis, when there is the best chance to induce a prolonged remission duration. A sequential approach should then be considered at first and subsequent relapses, when less intense and more palliative regimens are needed. The combination of bortezomib-dexamethasone or bortezomib-doxorubicin or lenalidomide-dexamethasone are currently recommended in the setting of relapsed myeloma patients. The choice of combination relies on previous exposure to such drugs as well as concomitant co-morbidities which might contraindicate the delivery of a specific compound (Figure 1). Cytogenetic abnormalities, such as deletion of chromosome 13 or chromosomal translocation (4;14) are considered negative prognostic factors.37 Unfortunately, most of the studies reported to date have not prospectively stratified patients based on cytogenetic abnormalities, making conclusions difficult. In the VMP patients,22 as well as in a smaller cohort of MPR patients,21 the event-free survival of patients with deletion of chromosome 13 or chromosomal translocation (4;14) was not significantly different from those who did not show such abnormalities. If these data are confirmed, it seems likely that a cytogenetically adapted strategy will represent the most rational, molecularly targeted approach to myeloma therapy. Potential conflicts of interest Two of the authors (AP, MB) have received scientific advisory-board and lecture fees from Pharmion, Celgene, and Janssen-Cilag. M.C. has received scientific advisoryboard, lecture fees and research funding from Janssen-Cilag and Novartis. The other authors declare that they have no conflict of interest. Acknowledgments Supported in part by the Università degli Studi di Torino, Fondazione Neoplasie Sangue Onlus, Associazione Italiana Leucemie, Compagnia di S. Paolo, Fondazione Cassa di Risparmio di Torino, Ministero dell’Università e della Ricerca (MIUR), and Consiglio Nazionale delle Ricerche (CNR), Italy. References 1. Ries LAG, Eisner MP, Kosary CL, Linet M, Tamra T, Young JL, Bunin GR (eds) SEER cancer statistics review, 1975-2000. National Cancer Institute. Available at: http//seer.cancer.gov// csr/1975_2001. Accessed on september 7, 2004. 2. Barlogie B, Kyle RA, Anderson KC, Greipp PR, Lazarus HM, Hurd DD et al. Standard chemotherapy compared with high- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 113 | 12th Congress of the European Hematology Association 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. dose chemoradiotherapy for multiple myeloma: final results of phase III US Intergroup trial S9321. J Clin Oncol 2006;24:929-36. Attal M, Harousseau JL, Facon T, Guidlhot F, Doyen C, Fuzibet JG et al. Single versus double autologous stem cell transplantation for multiple myeloma. N Engl J Med 2003;349:2495-502. Rajkumar SV, Blood E, Vesole D, Fonseca R, Greipp PR et al. Phase III clinical trial of thalidomide plus dexamethasone compared with dexamethasone alone in newly diagnosed multiple myeloma: a clinical trial co-ordinated by the Eastern Co-operative Oncology Group. J Clin Oncol 2006;24:431-6. Cavo M, Zamagni E, Tosi P, Tacchetti P, Cellini C, Cangini D et al. Superiority of thalidomide and dexamethasone over vincristine-doxorubicin dexamethasone (VAD) as primary therapy in preparation for autologous transplantation for multiple myeloma. Blood. 2005;106:35-9. Macro M, Divine M, Uzunhan Y, Jaccard A, Bouscary D, Leblond V et al. Dexamethasone+Thalidomide (Dex/Thal) Compared to VAD as a Pre-Transplant Treatment in Newly Diagnosed Multiple Myeloma (MM): A Randomized Trial. Blood 2006;108:57a[abstract]. Barlogie B, Tricot G, Anaissie E, Shaughnessy J, Rasmussen E, Van Rhee F et al. Thalidomide and hematopoietic-cell transplantation for multiple myeloma. N Engl J Med 2006;354; 1021-30. Lacy M, Gertz M, Dispenzieri A, Hayman S, Geyer S, Zeldenrust S et al. Lenalidomide plus dexamethasone (Rev/Dex) in newly diagnosed myeloma: response to therapy, time to progression and survival. Blood 2006;108:798a [abstract]. Rajkumar V, Jacobus S, Callander N, Callander N, Fonseca R, Vesole D A Randomized Phase III Trial of Lenalidomide Plus High-Dose Dexamethasone Versus Lenalidomide Plus LowDose Dexamethasone in Newly Diagnosed Multiple Myeloma (E4A03): A Trial Coordinated by the Eastern Cooperative Oncology Group. Blood 2006;108:799a[abstract]. Jagannath S, Durie B, Wolf JL, Camacho ES, Irwin D, Lutzky J et al. Long- term follow-up of patients treated with bortezomib alone and in combination with dexamethasone as front-line therapy for multiple myeloma. Blood 2006;108:796a[abstract]. Harousseau JL, Marit G, Caillot D, Casassus P, Facon T, Mohty M et al. VELCADE/Dexamethasone (Vel/Dex) Versus VAD as Induction Treatment Prior to Autologous Stem Cell Transplantation (ASCT) in Newly Diagnosed Multiple Myeloma (MM): An Interim Analysis of the IFM 2005-01 Randomized Multicenter Phase III Trial. Blood 2006;108:56a[abstract]. Oakervee HE, Popat R, Curry N, Smith P, Morris C, Drake M et al. PAD combination theraphy (PS-341/bortezomib, doxorubicin and dexamethasone) for previously untreated patients with multiple myeloma. Br J Haematol 2005;129:75562. Berenson JR, Crowley J, Grogan TM, Zangmeister J, Briggs AD, Mills GM et al. Maintenance therapy with alternate-day prednisone improves survival in multiple myeloma patients. Blood 2002;99:3163-8. Attal M, Harousseau JL, Leyvraz S, Doyen C, Huylin C, Benboubker L et al. Maintenance therapy with thalidomide improves survival in patients with multiple myeloma. Blood 2006;108:3289-94. Spencer A, Prince M, Roberts AW, Bradstock KF, Prosse IW First Analysis of the Australasian Leukaemia and Lymphoma Group (ALLG) Trial of Thalidomide and Alternate Day Prednisolone Following Autologous Stem Cell Transplantation (ASCT) for Patients with Multiple Myeloma (ALLG MM6). Blood 2006;108:58a[abstract]. Facon T, Mary JY, Pegourie B, Attal M, Renaud M, Sadoun A et al. Dexamethasone-based regimens versus melphalan-prednisone for elderly multiple myeloma patients ineligible for high-dose therapy. Blood 2006;107:1292-8. Palumbo A, Bringhen S, Petrucci MT, Musto P, Rossini F, Callea V et al. Intermediate-dose melphalan improves survival of myeloma patients aged 50 to 70: results of a randomized controlled trial. Blood 2004;104 :3052-7. Facon T, Mary J, Harousseau J, Huguet F, Berthou C, Grosbois B et al. Superiority of melphalan-prednisone (MP) + thalidomide (THAL) over MP and autologous stem cell transplantation in the treatment of newly diagnosed elderly patients with multiple myeloma. J Clin Oncol 2006 24(18S):1a[abstract]. Palumbo A, Bringhen S, Caravita T, Merla E, Carapella V, Callea V et al. Oral melphalan and prednisone chemotherapy plus thalidomide compared with melphalan and prednisone alone in elderly patients with multiple myeloma: randomised controlled trial. Lancet 2006; 367:825-31. 20. Bennet CL, Angelotta C, Yarnold PR, Evens AM, Zonder A, Raisch W et al. Thalidomide and lenalidomide-associated thromboembolism among patients with cancer. JAMA 2006;296:2559-60. 21. Palumbo A, Falco P, Falcone A, Corradini P, Di Raimondo F, Giuliani N et al. Oral Revlimid plus melphalan and prednisone (R-MP) for newly diagnosed multiple myeloma: a phase I-II study. Blood 2006;108(11):800a[abstract]. 22. Mateos MV, Hernandez JM, Hernandez MT, Guiterrez N-C, Palomera L, Fuertes M et al. Bortezomib plus melphalan and prednisone in elderly untreated patients with multiple myeloma: results of a multicenter phase I/II study. Blood 2006;108:2165-72. 23. Palumbo A, Giaccone L, Bertola A, Pregno P, Bringhen S, Rus C et al. Low-dose thalidomide plus dexamethasone is an effective therapy for advanced myeloma. Haematologica 2001;86:399-403. 24. Dimopoulos MA, Zervas K, Kouvatseas G, Galani E, Grigoraki V, Kiamouris C et al. Thalidomide and dexamethasone combination for refractory multiple myeloma. Ann Oncol 2001;12:991-5. 25. Offidani M, Corvatta L, Marconi M, Visani G, Alesiani F, Brunori M et al. Low-dose thalidomide with pegylated liposomal doxorubicin and high-dose dexamethasone for relapsed/refractory multiple myeloma: a prospective, multicenter, phase II study. Haematologica 2006;91:133-6. 26. Garcia-Sanz R, Gonzales-Porras JR, Hernandez JM, Zarzuela MP, Sureda A, Barrenetxea C et al. The oral combination of thalidomide, cyclophosphamide and dexamethasone (ThaCyDex) is effective in relapsed/refractory multiple myeloma. Leukemia 2004;18:856-63. 27. Weber DM, Chen C, Niesvizky R, Belch A, Stadtmauer E, Yu Z et al. Lenalidomide plus high-dose dexamethasone improved overall survival compared to high-dose dexamethasone alone for relapsed or refractory multiple myeloma (MM): Results of a North American phase III study (MM-009). J Clin Oncol 2006;24(18S): 7521a [abstract]. 28. Dimopoulos MA, Spencer A, Attal M, Prince M, Harousseua JL, Dmazynsk A et al. Study of lenalidomide plus dexamethasone alone in relapsed or refractory multiple myeloma (MM): results of a phase 3 study (MM-010). Blood 2005;106:6a [abstract]. 29. Baz R, Walker E, Karam MA, Jawde RA, Bruening K, Reed J et al. Lenalidomide and pegylated liposomal doxorubicin-based chemotherapy for relapsed or refractory multiple myeloma: safety and efficacy. Ann Oncol 2006;17:1766-71. 30. Morgan G, Schey S, Wu P, Srikanth M, Phekoo M, Jenner MW et al. Lenalidomide (Revlimid), in combination with cyclophosphamide and dexamethasone (CRD) is an effective regimen for heavily pre-treated myeloma patients. Blood 2006;108:355[abstract]. 31. Richardson PG, Sonneveld P, Schuster MW, Irwin D, Stadtmauer EA, Facon T et al. Bortezomib or high-dose dexamethasone for relapsed multiple myeloma. N Engl J Med 2005;352:2487-98. 32. Jagannath S, Richarson PG, Sonneveld P, Schster MW, Irwin D, Stadtmauer EA et al. Bortezomib appears to overcome the poor prognosis conferred by chromosome 13 deletion in phase 2 and 3 trials. Leukemia 2007;21:151-7. 33. Orlowski RZ, Zhuang SH, Parekh T, Xiu L, Harouseau JL. The combination of pegylated liposomal doxorubicin and bortezomib significantly improves time to progression of patients with relapsed/refractory multiple myeloma compared with bortezomib alone: results from a planned interim analysis of a randomized phase III study. Blood 2006;108: 404a[abstract]. 34. Reece DE, Piza G, Trudel S, Pantoja M, Chen , Mikhael JR et al. A phase I–II trial of bortezomib plus oral cyclophosphamide and prednisone for relapsed/refractory multiple myeloma. Blood 2006;108:3536a[abstract]. 35. Palumbo A, Ambrosini MT, Benevolo G, Pregno P, Pescosa N, Callea V et al. Bortezomib, melphalan, prednisone and thalidomide for relapsed multiple myeloma. Blood 2006 Dec 5; [Epub ahead of print]. 36. Child JA, Morgan GJ, Davies FE, et al. Medical Research Council Adult Leukaemia Working Party. High-dose chemotherapy with hematopoietic stem-cell rescue for multiple myeloma. N Engl J Med. 2003;348:1875-83. 37. Fonseca R, Blood R, Rue M, et al. Clinical and biologic implications of recurrent genomic aberrations in myeloma. Blood 2003;101:4569-70. | 114 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Chronic Lymphocytic Leukemia Genetics in chronic lymphocytic leukemia: impact for prognosis and treatment decisions U. Jäger M. Shehata D. Heintel R. Hubmann B. Kainz E. Porpaczy A. Hauswirth A. Gaiger Medical University of Vienna Department of Internal Medicine I, Division of Hematology and Hemostaseology Währinger Gürtel Vienna, Austria Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:115-121 he prognosis of patients with B-cell chronic lymphocytic leukemia (BCLL) has long been determined by the clinical staging systems of Binet and Rai.1-4 Unfortunately, these systems fail to identify patients in early stages whose disease will rapidly progress. In addition, the response of individual patients to specific therapies can scarcely be predicted by this approach. In recent years, numerous genetic approaches have provided new markers for prognosis and response prediction.5 The predictive potential of genetic factors associated with CLL outcome is determined by (i) its accessibility for routine use; (ii) its stability throughout the course of disease; and (iii) its sensitivity and specificity. Prognostic factors are largely dependent on the conventional therapeutic regimens used (i.e. chemotherapy) as well as on the availability of specific targeting drugs. This review will discuss the advances in the genetics of CLL with a special focus on molecular markers. The first part will focus on prognostic markers which have already been firmly established, while the second part will review the current status of molecular predictive markers and their potential influence on treatment decisions. T Prognostic markers Conventional cytogenetics Karyotypes from CLL cells collected from peripheral blood or bone marrow are difficult to assess. However, stimulation by CD40L or CpG oligonucleotides has yielded positive results in the majority of cases.6 One of the most important findings was that the number of chromosomal translocations has largely been underestimated. Patients with translcations have a poor prognosis with short treatment free and overall survival times.6 Recent advances were also made in identifying chromosomal regions predisposing for familial CLL. Regions on chromosomes 13q as well as 1, 3, 6, 12, and 17 have been linked to pathogenesis of inherited disease.7-9 However, while relatives of CLL patients have increased numbers of circulating CD19+/CD5+ B-cells (a phenomenon called B-cell monoclonal lymphocytosis, MBL), the risk factors leading to the final development of overt CLL are still unclear.10 Moreover, familial CLL does not seem to be associated with shorter survival in affected individuals.11 MicroRNAs (MiRs) are also connected to familial disease.12 However, their impact is not yet clear. Fluorescence in situ hybridization The prognostic value of aberrations has long been established following the hierarchical model described by Döhner et al.13,14 Half of the B-CLL cases have a del 13q indicating good prognosis. On the other hand, 11q deletions are associated with bulky disease and short survival times. This is even more pronounced for 17p deletions which predict for very poor outcome.15,16 Interphase cytogentics have been extended to a molecular level by microarray analysis in several instances.17–19 Thus, a number of genes over- or underexpressed in association with chromosomal aberrations have been identified. Some of these are directly related to the location on deleted or duplicated chromosomes (gene dosage effect). However, a number of genes from unaffected chromosomes change their expression, suggesting trans-acting effects. These genes have only partially been evaluated.20 Molecular prognostic markers Molecular markers can be classified according to their presence on the DNA level (mutations, polymorphisms) or on the RNA level (gene expression) (Table 1). Most markers are predictive at diagnosis, but dynamic markers predicting response to therapy (e.g.minimal residual disease) are also available (see also Table 4). hematology - the european hematology association education program | 2007; 3(1) | 115 | 12th Congress of the European Hematology Association Gene mutations Immunoglobulin VH-mutational status is now well established as a strong predictor of outcome.21-28 By convention, a 98% sequence homology to germline has been defined as a useful clinical cut-off between good (mutated) or poor (unmutated) prognosis. More detailed analysis has revealed that the 98% threshold is indeed relevant, but that some variation exists.29 Further analysis has revealed the prognostic relevance of specific VH-families: VH 1-69 cases are always unmutated CLL and mutated cases with a VH 3-21 have a poor outcome.30, 31 A number of non-immunoglobulin genes have been searched for mutations in CLL. Germline or somatic mutations were found in 5 of 42 sequenced microRNAs (miR) in 11 out 75 patients with CLL.12 Gene expression Perhaps the most important value of IgVH mutational status was its use as a discriminator of patient subgroups for further analysis in microarray studies. Gene expression profiling revealed the association of a number of genes previously thought to be unrelated to CLL. Depending on the use of CD19-selected/T-cell depleted or unpurified B-CLL samples, a variety of markers have been found since the initial experiments of Klein and Rosenwald in 2001.19,32-34 (Table 2) When CD19+ cells were used, the receptor kinase ZAP-70 was identified. The prognostic value of this genetic marker has now been well established by FACS-analysis or PCR.35-41 ZAP-70 protein expression predicts for treatment-free survival (TFS) and overall survival independently of mutation status. While convincing results were obtained by several groups using different protein detection methodology, harmonization efforts by the European Initiative in CLL Research (ERIC) have shown problems and were not successful to date.42 Moreover, contrasting results concerning association with IgVH mutational status have been observed. Particularly, 17p- samples cluster in the ZAP-70 negative group.43 Assessment of ZAP-70 mRNA expression by real time PCR requires positive (CD19) or negative selection of B-cells.39 Despite these drawbacks, ZAP-70 is a useful clinical marker and may also serve as a future target for specific signal transduction inhibitors. Among the markers with an even stronger correlation to IgVH mutational status,33,34 lipoprotein lipase has been extensively studied44-48 (Table 3). Its association with other markers (cytogenetic risk groups, molecular markers) as well as patient outcome (time to treatment, overall survival) is also strong. LPL is a stable marker which has been studied by real-time PCR in several large series using purified or unpurified CLL cells or even whole blood. No difference Table 1. Genetic markers in CLL with prognostic significance. Cytogenetic markers Conventional cytogenetics translocations FISH 17p-, 11q-, 13q-, +12 Molecular markers Mutations mRNA expression Minimal residual disease Ref. 6 13-19 IgVH-Status Micro RNAs ZAP70 LPL PEG 10 sarcoglycan ε septin 10 dystrophin AID telomerase L-selectin Integrin-β2 CLLU1 21-31 12 39 44-48 53 53 19 19 49-52 54 20 20 55 ASO-PCR 56-59 Table 2. Factors associated with IgVH mutational status by gene expression profiling. ZAP-70 LPL Dystrophin Gravin/AKAP12 BCL7A FGL2 Rosenwald A, J Exp Med 200132 CD19+ sorted Klein U, J Exp Med 200133 unsorted Vasconcelos Y, IWCLL 200334 CD19-selection Bilban M, Leukemia 200619 unsorted + + + + + - + + + + + + + + + + - + + + + + between purified and unpurified samples was observed in several studies, indicating its potential for easy and general use. Its specificity regarding IgVH mutational status is 89%, with a sensitivity of 68%, a positive predictive value of 83% and a negative predictive value of 78%48 (Table 3). Contrasting results are also observed.45 LPL can be combined with a downregulated marker (ADAM29) to increase specificity.44 While LPL protein can also be detected on normal Bcells, its cytoplasmatic expression correlates well with RNA levels.45 We have used the level of LPL expression as a discriminator for microrray analysis.19 Several markers emerging from this experiment have been validated by real time PCR. Among those, septin 10 and dystrophin (DMD) were strongly associated with time to treatment. The prognostic significance of some of | 116 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 these factors has also been confirmed by other groups (septin 10, DMD, AKAP12/gravin).32-34, 44-48 (Tables 2 and 3) In addition, LPL expression correlated with several functional modules including the MTA3 and fatty acid degradation pathways.19 Using special statistical methods exploiting the LPL-associated gene expression signature we have shown that LPL-positive CLL cells show similarities to other tissues like fat, muscle and dendritic cells. This suggests that LPL mRNA and protein expression may be of functional importance. Expression of other markers was also linked to prognosis. The gene responsible for somatic mutations in immunoglobulins (activation induced cytidine deaminase – AID) is overexpressed in high-risk (unmutated) CLL cases.49-52 We have investigated the prognostic significance of PEG10. This maternally expressed gene is overexpressed in high-risk CLL in parallel with sarcoglycan ε which resides within the same locus on chromosome 7q21. Knock-down of PEG10 expression in primary CLL patient cells results in increased apoptotic cell death.53 Another functionally important target is the telomerase gene which is overexpressed in CLL cells of patients with poor prognosis.54 Additional prognostic factors include L-selectin and integrin-β2.20 A very CLL-specific gene is CLLU1 whose mRNA expression level can predict time to initiation of treatment and survival in CLL patients.55 One of the most significant findings in the field of CLL research was the detection of certain microRNA genes which are over- or underexpressed in conjunction with certain chromosomal aberrations.12,18 Specific miR expression signatures are correlated with IgVH mutational status, ZAP-70 expression and treatment-free survival indicating prognostic importance. Minimal residual disease Molecular monitoring of residual CLL cells during therapy has been used as a dynamic marker during therapy. Eradication of MRD below detection levels of tailored PCR (ASO-PCR) or multicolour FACS is a predictor of favourable outcome.56,57 This has been shown for induction therapy with the antibody alemtuzumab as well as for autologous or allogeneic stem cell transplantation.58,59 Table 3. Studies on lipoprotein lipase mRNA and protein expression as a prognostic factor. Method n Microarray purified CLL cells Association with IgVH mutation status OS/EFS TFS Association yes - - Specific comments with other markers Publication author/ref. ZAP70, BCL7A and others J Exp Med 2001 Rosenwald A,32 J Exp Med 2001 Klein U,33 signature related to fat, Leukemia muscle, DC’s; 2006 functional modules: MTA3, fatty acid degradation Bilban M,19 Microarray purified + unpurified CLL cells 34 + NA NA BCL7A, ZAP70, gravin, DMD, FGL2 and others RQ-PCR +Microarray Purified CLL cells 42 NA NA NA Septin10, DMD, gravin RQ-PCR + + competitive PCR Unpurified cells 127 + 99% NA/yes ? ADAM29, ZAP70 significance in Binet A Blood 2005 Oppezzo P, 44 RQ-PCR Unpurified cells 104 + Odds ratio 25.9 84% discrimination no/NA yes cytogenetics significance in Binet A, LPL protein correlates with mRNA Leukemia 2005 Heintel D,45 RQ-PCR Unpurified cells 130 + yes -ZAP70, ADAM29, Septin10, AKAP12, DMD, NRIP1, TPM2, CLECSF2 10 markers selected unpurified more realiable than ZAP70 Haematologica van’t Veer MB,46 2006 RQ-PCR Unpurified cells RQ-PCR whole blood CD19-selected 133 NA yes?/NA - ADAM29, CD38, ZAP70 stable over time Leuk Lymphoma 2006 Nückel H,47 50 + 83% pos. pred. v. 78% neg. pred. v. yes/NA yes ZAP70 unpurified + CD19 selected equal Clin Chem 2006 van Bockstaele F, 48 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 117 | 12th Congress of the European Hematology Association Prediction of response and influence on treatment decisions Cytogentics/FISH Chromosome 17p deletions or p53 mutations result in poor response to fludarabine and rituximab which can be overcome by therapy with alemtuzumab60,61 (Table 4). Alemtuzumab is particularly effective when combined with high-dose steroids.62 The predictive value of trisomy 12 is annulled when fludarabine-containing regimens are used (Stilgenbauer, personal communication). Patients with deletions in 17p or 11q have been shown to respond to flavopiridol.63 While combination chemoimmunotherapy with rituximab, pentostatin and cyclophosphamide was not effective in 17ppatients, it was very effective in patients with 11q deletions.64 These novel data will obviously have consequences for treatment selection and expected response and will lead the way to tailored therapy. Minimal residual disease MRD detection may not only be used as a measure of outcome, but could potentially serve to guide therapy in individual patients. In particular, response assessment after induction therapy could be used to tailor maintenance treatment with alemtuzumab or rituximab.58,65 Since the clinical outcome of patients who become MRD-negative is substantially improved these molecular data may also impact on transplant decisions. Thus, MRD data will contribute to challange the paradigm that CLL should not be treated aggressively.57,66-68 In vitro evidence for response to specific targeting drugs Molecular markers have led to the detection of potentally active novel agents or off-label use of known drugs against CLL (Table 4). While these data are still based on in vitro or ex vivo observations, some of the agents used are close to clinical testing. Inhibitors of activated heat shock protein 90 (HSP90) have been shown to influence survival of B-cells expressing high levels of ZAP70.69 Specific ZAP70 inhibitors are currently being developed. Since there is strong evidence for the functional importance of LPL in high-risk CLL, it is noteworthy that lipoprotein lipase inhibitors are already on the market for metabolic disorders. There is preliminary evidence that one of these agents (orlistat) leads to apoptosis in B-CLL cells.70 Since orlistat has low toxicity, its off-label use in BCLL seems called for. We have shown that PI3kinase/AKT inhibitors (Wortmannin, Ly294002) also effectively induce apoptosis of primary B-CLL cells.71 A number of genes important for CLL survival have been knocked down by siRNA technology. Thus, even miR genes or others may eventually serve as targets for therapeutic interventions.12,18 Molecules detected by molecular methods may also serve as targets for T-cell immunotherapy. One such example is the CLL specific antigen fibromodulin which allows expansion of specific CD8+ autologous T lymphocytes in vitro.72 Table 4. Impact of selected genetic markers on treatment decisions. Prognostic Cytogenetics /FISH 17p- Influence of treatment decision, response to specific drugs Reference (yes) effective: alemtuzumab, flavopirdol, high-dose steroids; ineffective: fludarabine, rituximab 60-62 11p- yes effective: flavopiridol, pentostatin (PCR) not very effective: alemtuzumab 63, 64 +12 yes prognostic power lost after treatment with FC yes yes no unclear unclear effect of rituximab dependent on genotype 73 yes HSP90 inhibitors effective in vitro, direct inhibitors in development 69 yes no no yes LPL inhibitor orlistat effective in vitro Antiapoptotic effect of Wortmannin, Ly294002 in vitro Elicits autologous CD8+ T-cell response in vitro Multidrug resistance, target for specific agents 70 71 72 75 no yes fludarabine response influenced maintenance treatment with alemtuzumab Molecular markers Mutation IgVH MiR genes FCγReceptor IIIA Expression ZAP70 LPL PI3-Kinase Fibromodulin MDR1 Dynamic markers microarray p53 signature Minimal residual disease | 118 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) 74 58, 65 Vienna, Austria, June 7-10, 2007 Pharmacogenomics In addition to general static and dynamic prognostic markers related to the disease, several genetic markers associated with response to specific therapies have been investigated (Table 4). Polymorphisms of the FC receptorγIIIA (FCGR3A) generally predict response to rituximab.73 Rosenwald et al. have studied the gene expression pattern of CLL cells after therapy with fludarabine in vivo and in vitro and have shown that fludarabine induced changes which resulted in a p53-related expression signature.74 The results predict that fludarabine treatment will lead to selection of p53-mutated CLL clones. The phenomenon of multi-drug resistance has recently been investigated.75 Conclusions Genetic markers have already contributed many important insights into the biology of B-CLL. Some genetic markers have been established as routinely used prognostic factors in addition to the traditional staging systems.76 This is particularly true for cytogenetic aberrations detected by FISH. Other markers like ZAP70 have shown their prognostic power in large patient series, but need to be more thoroughly harmonized for standard use; markers like IgVH mutational status and minimal residual disease detection by PCR are harmonized, but cannot easily used in daily routine. The least developed group including lipoprotein lipase, AID, or micro RNAs have not reached either one of these stages, but are potentially interesting prognostic markers. There is strong evidence that several of the predictive markers will influence treatment decisions for tailored therapy.77,78 While generalized routine use of these data cannot be recommended to date, results from randomized trials are imminent. These trials have been powered to answer the questions related to the rational use of specific therapies on the basis of identification of molecular genetic markers. Acknowledgements This work has been supported by the Austrian Human Genome Project (GEN-AU c.h.i.l.d.). References 1. Rai KR, Sawitsky A, Cronkite EP, Chanana AD, Levy RN, Pasternack BS. Clinical staging of chronic lymphocytic leukemia. Blood 1975;46:219-34. 2. Binet JL, Lepoprier M, Dighiero G, Charron D, D'Athis P, Vaugier G, et al. A clinical staging system for chronic lymphocytic leukemia: prognostic significance. Cancer 1977;40:85564. 3. Rozman C, Montserrat E. Chronic lymphocytic leukemia. N Engl J Med. 1995;333:1052-7. 4. Kipps TJ. Chronic lymphocytic leukemia. Curr Opin Hematol 2000;7:223-34. 5. Montserrat E. New prognostic markers in CLL. Hematology Am Soc Hematol Educ Program 2006;279-84. 6. Mayr C, Speicher MR, Kofler DM, Buhmann R, Strehl J, Busch R, et al. Chromosomal translocations are associated with poor prognosis in chronic lymphocytic leukemia. Blood 2006; 107: 742-51. 7. Ng D, Toure O, Wei MH, Arthur DC, Abbasi F, Fontaine L, et al. Identification of a novel chromosome region, 13q21.33q22.2, for susceptibility genes in familial chronic lymphocytic leukaemia. Blood 2007;109:916-25. 8. Goldin LR, Pfeiffer RM, Li X, Hemminki K. Familial risk of lymphoproliferative tumors in families of patients with chronic lymphocytic leukemia: results from the Swedish FamilyCancer Database. Blood 2004;104:1850-4. 9. Caporaso N, Marti GE, Goldin L. Perspectives on familial chronic lymphocytic leukemia: genes and the environment. Semin Hematol 2004;42:201-6. 10. Marti GE, Rawstron AC, Ghia P, Hillmen P, Houlston RS, Kay N, et al. The International Familial CLL Consortium. Diagnostic criteria for monoclonal B-cell lymphocytosis. Br J Haematol 2005;130:325-32. 11. Mauro FR, Giammartini E, Gentile M, Sperduti I, Valle V, Pizzuti A, et al. Clinical features and outcome of familial chronic lymphocytic leukemia. Haematologica 2006;91:111720. 12. Calin GA, Ferracin M, Cimmino A, Di Leva G, Shimizu M, Wojcik SE, et al. A MicroRNA signature associated with prognosis and progression in chronic lymphocytic leukaemia. N Engl J Med 2005;352:1667-76. 13. Dohner H, Stilgenbauer S, Benner A, Leupolt E, Krober A, Bullinger L, et al. Genomic aberrations and survival in chronic lymphocytic leukemia. N Engl J Med 2000;343:1910-6. 14. Catovsky D, Richards S, Matutes E et al. Response to therapy and survival in CLL is influenced by genetic markers. preliminary analysis from the LRF CLL4 trial. Blood 2004;104: abstract 8a. 15. Dohner H, Stilgenbauer S, James MR, Benner A, Weilguni T, Bentz M, et al. 11q deletions identify a new subset of B-cell chronic lymphocytic leukemia characterized by extensive nodal involvement and inferior prognosis. Blood 1997;89: 2516-22. 16. Oscier DG, Gardiner AC, Mould SJ, Glide S, Davis ZA, Ibbotson RE, et al. Multivariate analysis of prognostic factors in CLL: clinical stage, IGVH gene mutational status, and loss or mutation of the p53 gene are independent prognostic factors. Blood 2002;100:1177-84. 17. Haslinger C, Schweifer N, Stilgenbauer S, Dohner H, Lichter P, Kraut N, et al. Microarray gene expression profiling of B-cell chronic lymphocytic leukemia subgroups defined by genomic aberrations and VH mutation status. J Clin Oncol 2004;22: 3937-49. 18. Calin GA, Liu CG, Sevignani C, Ferracin M, Felli N, Dumitru CD, et al. MicroRNA profiling reveals distinct signatures in B cell chronic lymphocytic leukemias. Proc Natl Acad Sci USA 2002;99:15524-9. 19. Bilban M, Heintel D, Scharl T, Woelfel T, Auer MM, Porpaczy E, et al. German CLL Study Group. Deregulated expression of fat and muscle genes in B-cell chronic lymphocytic leukemia with high lipoprotein lipase expression. Leukemia 2006;20: 1080-8. 20. Stratowa C, Loffler G, Lichter P, Stilgenbauer S, Haberl P, Schweifer N, Dohner H, Wilgenbus KK. CDNA microarray gene expression analysis of B-cell chronic lymphocytic leukemia proposes potential new prognostic markers involved in lymphocyte trafficking. Int J Cancer. 2001;91:474-80. 21. Hamblin TJ, Davis Z, Gardiner A, Oscier DG, Stevenson FK. Unmutated Ig V(H) genes are associated with a more aggressive form of chronic lymphocytic leukemia. Blood 1999; 94:1848-54. 22. Damle RN, Wasil T, Fais F, Ghiotto F, Valetto A, Allen SL, et al. Ig V gene mutation status and CD38 expression as novel prognostic indicators in chronic lymphocytic leukemia. Blood 1999; 94:1840-7. 23. Hamblin TJ, Orchard JA, Ibbotson RE, Davis Z, Thomas PW, Stevenson FK, et al. CD38 expression and immunoglobulin variable region mutations are independent prognostic variables in chronic lymphocytic leukemia, but CD38 expression may vary during the course of the disease. Blood 2002; 99: 1023-9. 24. Krober A, Seiler T, Benner A, Bullinger L, Bruckle E, Lichter P, et V(H) mutation status, CD38 expression level, genomic aberrations, and survival in chronic lymphocytic leukemia. Blood 2002;100:1410-6. 25. Vasconcelos Y, Davi F, Levy V, Oppezzo P, Magnac C, Michel A, et al. Binet's staging system and VH genes are independent Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 119 | 12th Congress of the European Hematology Association 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. but complementary prognostic indicators in chronic lymphocytic leukemia. J Clin Oncol 2003;21:3928-32. Thunberg U, Johnson A, Roos G, Thorn I, Tobin G, Sallstrom J, et al. CD38 expression is a poor predictor for VH gene mutational status and prognosis in chronic lymphocytic leukemia. Blood 2001;97:1892-4. Stilgenbauer S, Bullinger L, Lichter P, Dohner H. German CLL Study Group (GCLLSG). Chronic lymphocytic leukemia. Genetics of chronic lymphocytic leukemia: genomic aberrations and V(H) gene mutation status in pathogenesis and clinical course. Leukemia 2002;16:993-1007. Guarini A, Gaidano G, Mauro FR, Capello D, Mancini F, De Propris MS, et al. Chronic lymphocytic leukemia patients with highly stable and indolent disease show distinctive phenotypic and genotypic features. Blood 2003;102:4497-506. Oscier DG, Gardiner AC, Mould SJ, Glide S, Davis ZA, Ibbotson RE, et al. Multivariate analysis of prognostic factors in CLL: clinical stage, IGVH gene mutational status, and loss or mutation of the p53 gene are independent prognostic factors.Blood 2002;100:1177-84. Thorselius M, Krober A, Murray F, Thunberg U, Tobin G, Buhler A, et al. Strikingly homologous immunoglobulin gene rearrangements and poor outcome in VH3-21-using chronic lymphocytic leukemia patients independent of geographic origin and mutational status. Blood 2006;107:2889-94. Kienle D, Benner A, Krober A, Winkler D, Mertens D, Buhler A, et al. Distinct gene expression patterns in chronic lymphocytic leukemia defined by usage of specific VH genes. Blood 2006;107:2090-3. Rosenwald A, Alizadeh AA, Widhopf G, Simon R, Davis RE, Yu X, et al. Relation of gene expression phenotype to immunoglobulin mutation genotype in B cell chronic lymphocytic leukemia. J Exp Med 2001;194:1639-47. Klein U, Tu Y, Stolovitzky GA, Mattioli M, Cattoretti G, Husson H, et al. Gene expression profiling of B cell chronic lymphocytic leukemia reveals a homogeneous phenotype related to memory B cells. J Exp Med 2001;194:1625-38. Vasconcelos Y, De Vos J, Vallat L, Reme T, Lalanne AI, Wanherdrick K, et al. French Cooperative Group on CLL. Gene expression profiling of chronic lymphocytic leukemia can discriminate cases with stable disease and mutated Ig genes from those with progressive disease and unmutated Ig genes. Leukemia 2005;19:2002-5. Chen L, Widhopf G, Huynh L, Rassenti L, Rai KR, Weiss A, et al. Expression of ZAP-70 is associated with increased B-cell receptor signaling in chronic lymphocytic leukemia. Blood 2002;100:4609-14. Wiestner A, Rosenwald A, Barry TS, Wright G, Davis RE, Henrickson SE, et al. Staudt LM. ZAP-70 expression identifies a chronic lymphocytic leukemia subtype with unmutated immunoglobulin genes, inferior clinical outcome, and distinct gene expression profile. Blood 2003;101:4944-51. Crespo M, Bosch F, Villamor N, Bellosillo B, Colomer D, Rozman M, et al. ZAP-70 expression as a surrogate for immunoglobulin-variable-region mutations in chronic lymphocytic leukemia. N Engl J Med 2003;348:1764-75. Rai KR, Chiorazzi N. Determining the clinical course and outcome in chronic lymphocytic leukemia. N Engl J Med 2003;348:1797-9. Durig J, Nuckel H, Cremer M, Fuhrer A, Halfmeyer K, Fandrey J, et al. ZAP-70 expression is a prognostic factor in chronic lymphocytic leukemia. Leukemia 2003;17:2426-34. Orchard JA, Ibbotson RE, Davis Z, Wiestner A, Rosenwald A, Thomas PW, et al. ZAP-70 expression and prognosis in chronic lymphocytic leukaemia. Lancet 2004;363:105-11. Rassenti LZ Huynh L, Toy TL, Chen L, Keating MJ, Gribben JG, et al. ZAP-70 compared with immunoglobulin heavychain gene mutation status as a predictor of disease progression in chronic lymphocytic leukemia. N Engl J Med 2004;351:893-901. Letestu R, Rawstron A, Ghia P, Villamor N, Leuven NB, Boettcher S, et al. Evaluation of ZAP-70 expression by flow cytometry in chronic lymphocytic leukemia: A multicentric international harmonization process.Cytometry B Clin Cytom 2006;70:309-14. Krober A, Bloehdorn J, Hafner S, Buhler A, Seiler T, Kienle D, et al. Additional genetic high-risk features such as 11q deletion, 17p deletion, and V3-21 usage characterize discordance of ZAP-70 and VH mutation status in chronic lymphocytic leukemia. J Clin Oncol 2006;24:969-75. Oppezzo P, Vasconcelos Y, Settegrana C, Geannel D, Vuillier F, Legarff-Tavernier M, et al. French Cooperative Group on CLL. The LPL/ADAM29 expression ratio is a novel prognosis indicator in chronic lymphocytic leukaemia. Blood 2005;106:650- 657. 45. Heintel D, Kienle D, Shehata M, Kröber A, Kroemer E, Schwarzinger I, et al. CLL Study Group. High expression of lipoprotein lipase in poor risk B-cell chronic lymphocytic leukaemia. Leukemia 2005;19:1216-23. 46. van’t Veer MB, Brooijmans AM, Langerak AW, Verhaaf B, Goudswaard CS, Graveland WJ, et al. The predictive value of lipoprotein lipase for survival in chronic lymphocytic leukemia. Haematologica 2006;91:56-63. 47. Nückel H, Huttmann A, Klein-Hitpass L, Schroers R, Führer A, Sellmann L, et al. Lipoprotein lipase expression is a novel prognostic factor in B-cell chronic lymphocytic leukemia. Leuk Lymphoma 2006;47:1053-61. 48. Van Bockstaele F, Pede V, Janssens A, Callewaert F, Offner F, Verhasselt B, et al. Lipoprotein lipase mRNA in whole blood is a prognostic marker in B cell chronic lymphocytic leukaemia. Clin Chem 2006 Dec 12; (Epub ahead of print) 49. Oppezzo P, Vuillier F, Vasconcelos Y, Dumas G, Magnac C, Payelle-Brogard B, et al. Chronic lymphocytic leukemia B cells expressing AID display a dissociation between class switch recombination and somatic hypermutation. Blood 2003;101:4029-32. 50. McCarthy H, Wierda WG, Barron LL, Cromwell CC, Wang J, Coombes KR, et al. High Expression of Activation-Induced Cytidine Deaminase (AID) and Splice Variants is a Distinctive Feature of Poor Prognosis Chronic Lymphocytic Leukemia. Blood. 2003;101:4903-8. 51. Albesiano E, Messmer BT, Damle RN, Allen SL, Rai KR, Chiorazzi N. Activation-induced cytidine deaminase in chronic lymphocytic leukemia B cells: expression as multiple forms in a dynamic, variably sized fraction of the clone. Blood. 2003;102:3333-9. 52. Heintel D, Kroemer E, Kienle D, Schwarzinger I, Gleiss A, Schwarzmeier J, et al. German CLL Study Group. High expression of activation-induced cytidine deaminase (AID) mRNA is associated with unmutated IGVH gene status and unfavourable cytogenetic aberrations in patients with chronic lymphocytic leukaemia. Leukemia 2004;18:756-62. 53. Kainz B, Shehata M, Bilban M, et al. Overexpression of the paternally expressed gene 10 (PEG10) from the imprinted locus on chromosome 7q21 in high-risk B-cell chronic lymphocytic leukemia. 2007; manuscript submitted. 54. Tchirkov A, Chaleteix C, Magnac C, Vasconcelos Y, Davi F, Michel A, et al. hTERT expression and prognosis in B-chronic lymphocytic leukemia. Ann Oncol. 2004;15:1476-80. 55. Buhl AM, Jurlander J, Geisler CH, Pedersen LB, Andersen MK, Josefsson P, et al. CLLU1 expression levels predict time to initiation of therapy and overall survival in chronic lymphocytic leukemia. Eur J Haematol 2006;76:455-64. 56. Bottcher S, Ritgen M, Pott C, Bruggemann M, Raff T, Stilgenbauer S, et al. Comparative analysis of minimal residual disease detection using four-color flow cytometry, consensus IgH-PCR, and quantitative IgH PCR in CLL after allogeneic and autologous stem cell transplantation. Leukemia 2004;18:1637-45. 57. Nabhan C, Coutre S, Hillmen P. Minimal residual disease in chronic lymphocytic leukaemia: is it ready for primetime? Br J Haematol 2007;136:379-92. 58. Wendtner CM, Ritgen M, Schweighofer CD, Fingerle-Rowson G, Campe H, Jager G, et al. German CLL Study Group (GCLLSG). Consolidation with alemtuzumab in patients with chronic lymphocytic leukemia (CLL) in first remission--experience on safety and efficacy within a randomized multicenter phase III trial of the German CLL Study Group (GCLLSG). Leukemia 2004;18:1093-101. 59. Moreton P, Kennedy B, Lucas G, Leach M, Rassam SM, Haynes A, et al. Eradication of minimal residual disease in Bcell chronic lymphocytic leukemia after alemtuzumab therapy is associated with prolonged survival. J Clin Oncol 2005;23:2971-9. 60. Stilgenbauer S, Dohner H. Campath-1H-induced complete remission of chronic lymphocytic leukemia despite p53 gene mutation and resistance to chemotherapy. N Engl J Med 2002;347:452-3. 61. Lozanski G, Heerema NA, Flinn IW, Smith L, Harbison J, Webb J, et al. Alemtuzumab is an effective therapy for chronic lymphocytic leukemia with p53 mutations and deletions. Blood 2004;103:3278-81. 62. Pettitt AR, Matutes E, Oscier D. Alemtuzumab in combination with high-dose methylprednisolone is a logical, feasible and highly active therapeutic regimen in chronic lymphocytic leukaemia patients with p53 defects. Leukemia 2006;20:14415. 63. Byrd JC, Lin TS, Dalton JT, Wu D, Phelps MA, Fischer B, et al. | 120 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 64. 65. 66. 67. 68. 69. 70. Flavopiridol administered using a pharmacologically derived schedule is associated with marked clinical efficacy in refractory, genetically high-risk chronic lymphocytic leukaemia. Blood 2007;109:399-404. Kay NE, Geyer SM, Call TG, Shanafelt TD, Zent CS, Jelinek DF, et al. Combination chemoimmunotherapy with pentostatin, cyclophosphamide, and rituximab shows significant clinical activity with low accompanying toxicity in previously untreated B chronic lymphocytic leukemia. Blood 2007;109: 405-11. Montillo M, Tedeschi A, Miqueleiz S, Veronese S, Cairoli R, Intropido L, et al. Alemtuzumab as consolidation after a response to fludarabine is effective in purging residual disease in patients with chronic lymphocytic leukemia. J Clin Oncol 2006;24:2337-42. Montserrat E. Treatment of chronic lymphocytic leukemia: achieving minimal residual disease-negative status as a goal.J Clin Oncol 2005;23:2884-5. Ritgen M, Stilgenbauer S, von Neuhoff N, Humpe A, Bruggemann M, Pott C, et al. Graft-versus-leukemia activity may overcome therapeutic resistance of chronic lymphocytic leukemia with unmutated immunoglobulin variable heavychain gene status: implications of minimal residual disease measurement with quantitative PCR. Blood 2004;104:2600-2. Moreno C, Villamor N, Colomer D, Esteve J, Martino R, Nomdedeu J, et al. Allogeneic stem-cell transplantation may overcome the adverse prognosis of unmutated VH gene in patients with chronic lymphocytic leukemia. J Clin Oncol 2005;23:3433-8. Castro JE, Prada CE, Loria O, Kamal A, Chen L, Burrows FJ, et al. ZAP-70 is a novel conditional heat shock protein 90 (Hsp90) client: inhibition of Hsp90 leads to ZAP-70 degradation, apoptosis, and impaired signaling in chronic lymphocytic leukemia. Blood 2005;106:2506-12 Pallasch CP, Schwamb J, Schulz A, Debey S, Kofler D, Schultze JL et al. Overexpression of Lipases Enables Specific Cytotoxicity by the Lipase Inhibitor Orlistat in Chronic Lymphocytic Leukemia Cells. ASH Annual Meeting Abstracts. Blood 2006; 108: abtract 2800. 71. Shehata M, Schnabl S, Demirtas D, Schwarzmeier JD, Hilgarth M, Duechler M, et al. Lymphoid Microenvironment Inhibits Apoptosis in B-CLL Cells: Involvement of PI3-K/AKT Pathway and PTEN. ASH Annual Meeting Abstracts. Blood 2006; 108: abstract 1441. 72. Mayr C, Bund D, Schlee M, Moosmann A, Kofler DM, Hallek M, et al. Fibromodulin as a novel tumor-associated antigen (TAA) in chronic lymphocytic leukemia (CLL), which allows expansion of specific CD8+ autologous T lymphocytes. Blood 2005;105:1566-73. 73. Kim DH, Jung HD, Kim JG, Lee JJ, Yang DH, Park YH, et al. FCGR3A gene polymorphisms may correlate with response to frontline R-CHOP therapy for diffuse large B-cell lymphoma. Blood 2006;108:2720-5. 74. Rosenwald A, Chuang EY, Davis RE, Wiestner A, Alizadeh AA, Arthur DC, et al. Fludarabine treatment of patients with chronic lymphocytic leukemia induces a p53-dependent gene expression response. Blood 2004;104:1428-34. 75. Matthews C, Catherwood MA, Larkin AM, Clynes M, Morris TC, Alexander HD. MDR-1, but not MDR-3 gene expression, is associated with unmutated IgVH genes and poor prognosis chromosomal aberrations in chronic lymphocytic leukemia. Leuk Lymphoma 2006;47:2308-13. 76. Binet JL, Caligaris-Cappio F, Catovsky D, Cheson B, Davis T, Dighiero G, et al. International Workshop on Chronic Lymphocytic Leukemia (IWCLL).Perspectives on the use of new diagnostic tools in the treatment of chronic lymphocytic leukemia. Blood 2006;107:859-61. 77. Gowda A, Byrd JC. Use of prognostic factors in risk stratification at diagnosis and time of treatment of patients with chronic lymphocytic leukemia. Curr Opin Hematol 2006;13:266-72. 78. Byrd JC, Gribben JG, Peterson BL, Grever MR, Lozanski G, Lucas DM, et al. Select high-risk genetic features predict earlier progression following chemoimmunotherapy with fludarabine and rituximab in chronic lymphocytic leukemia: justification for risk-adapted therapy. J Clin Oncol 2006 ;24:437-43. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 121 | Chronic Lymphocytic Leukemia State-of-the-art treatment of chronic lymphocytic leukemia M. Hallek On behalf of the German CLL Study Group Klinik I für Innere Medizin Universität zu Köln, Germany Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:122-128 he last decade has seen rapid progress in the management of chronic lymphocytic leukemia (CLL). Fludarabine and a monoclonal antibody, alemtuzumab, have been approved by the European and American regulatory agencies. Additional monoclonal antibodies (anti-CD20; anti-CD23; anti-MHC II; anti-CD40) as well as other drugs (flavopiridol, bendamustine) are currently being tested in clinical trials. In addition, the increased experience with allogeneic progenitor cell transplantation has offered this intensified treatment option to physically fit patients at very high risk of relapse or at the time of relapse. Similarly, rapid progress has been achieved with regard to new diagnostic tests to identify prognostic subgroups in CLL and to assess their response to therapy. However, the optimal use of these different therapeutic and diagnostic modalities remains to be determined. This review attempts to summarize the best developments today in the initial management of CLL. T Clinical staging and prognostic markers The survival period from the time of diagnosis of CLL varies between 2 and more than 10 years, depending on stage. The staging systems of Rai et al.1 and Binet et al.2 are used to predict the prognosis. Both are based on the extent of lymphadenopathy, splenomegaly, and hepatomegaly on physical examination and on the degree of anemia and thrombocytopenia in peripheral cell counts. These simple studies are inexpensive and can be applied to every patient without sophisticated technical equipment. Both staging systems describe three major prognostic subgroups. However, it has long been recognized that the above clinical staging systems are not sufficient to predict the individual prognosis, especially in the early stages of disease (Binet stage A, Rai stages 0–II) and in younger patients. Therefore, additional parameters have been identified allowing a more accurate prediction of the prognosis | 122 | of CLL patients (Table 1). While these parameters are effective in predicting the prognosis (survival, time to progression) of individual patients independent of the Binet or Rai stage, only molecular cytogenetics hasve proven useful in predicting the response to chemotherapy in CLL. Therefore, the assessment of most parameters remains a task of clinical trials, but is not recommended in general practice. The only exception is the use of molecular cytogenetics (FISH), since the occurrence of del(17p13.1) or del(11q22.3) is associated with a shorter PFS or overall survival.3,4 Therefore, molecular cytogenetics should be performed prior to first treatment. Treatment decision Any decision to treat should be guided by clinical staging, the presence of symptoms, and disease activity. Evidence that current treatment can improve outcome is only available for patients with Rai III and IV or Binet B and C stages. Patients in earlier stages (Rai 0-II, Binet A and B) are generally not treated but monitored with a watch and wait strategy. In early stages, treatment is necessary only if symptoms associated with the disease occur (e.g., B symptoms, decreased performance status, or symptoms or complications from hepatomegaly, splenomegaly, and lymphadenopathy). High disease activity, often defined by a lymphocyte doubling time of less than 6 months or by rapidly growing lymph nodes, is also an indication to treat. In contrast, even in advanced disease (Binet C), the absence of disease progression (e.g., with a stable platelet count around 80,000/µL) may sometimes justify a watch and wait strategy. Response assessment As with other malignancies, eradication of the disease is a desired endpoint of CLL treatment, especially in younger patients. New detection technologies have found that most patients who achieve a complete response as defined by the National Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 1. Parameters predicting the prognosis of CLL independent of disease stage. treatment (chlorambucil plus prednisone vs. cladribine, 82% vs. 78% at 2 years). Parameter Reference Combination chemotherapy with purine analogs Aberrations in chromosomes 13 (13q-), 11 (11q-) and 17 (17p-) 45 Cytoplasmic ZAP70 in CLL cells 46,47 Expression of CD38 on CLL cells 48,49 Lymphocyte doubling time 50 Serum β2-microglobulin concentration 51 Serum levels of soluble CD23 52,53 Serum thymidine kinase activity 54 Somatic hyper-mutations of the immunoglobulin VH-gene region 48,55 Cancer Institute-sponsored working group (NCI-WG) guidelines5 typically have minimal residual disease (MRD). Critical in this assessment is a standardization of the techniques used to define MRD. The most sensitive techniques are 4-color flow cytometry and realtime quantitative polymerase chain reaction (PCR). Fortunately, the techniques for assessing MRD have now become standardized.6 Nevertheless, the clinical relevance of MRD testing needs to be verified by prospective clinical trials and is not recommended for general practice. Clinical trials that aim to achieve long-lasting complete remissions should include a test for MRD, because eradication of leukemia may have a strong prognostic impact..7-9 First-line treatment Monotherapy with purine analogs Three purine analogues are currently used in CLL: fludarabine, pentostatin, and cladribine (2-CdA). Fludarabine remains by far the best studied compound of the three in CLL. Fludarabine monotherapy produces superior overall response (OR) rates compared with other treatment regimens containing alkylating agents or corticosteroids.10-12 In three Phase III studies in treatment-naïve CLL patients (Table 2), fludarabine induced more remissions and more complete remissions (CR) (7-40%) than other conventional chemotherapies, like CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone), CAP (cyclophosphamide, doxorubicin, prednisone), or chlorambucil.12-14 Despite the superior efficacy of fludarabine, overall survival is not improved by this drug when used as single agent.12-15 Similarly, the comparison of cladribine monotherapy to chlorambucil plus prednisone in one Phase III trial has yielded a higher CR rate of 47% versus 12% respectively (Table 2). However, this difference did not result in a longer survival after cladribine first-line Fludarabine has been evaluated in a variety of combination regimens. The combination of fludarabine and another purine analog, cytarabine, appears to be less effective than fludarabine alone, while the combination of fludarabine with chlorambucil or prednisone increases hematological toxicity without improving the response rate compared with fludarabine alone (response rates 27–79%).12,16 The most thoroughly studied combination chemotherapy for CLL is fludarabine plus cyclophosphamide (FC) (Table 2).16-19 In preliminary, non-comparative trials, the overall response rates did not appear to be better than with fludarabine alone, but the addition of cyclophosphamide appeared to improve the quality of response. This combination, with or without mitoxantrone, has achieved response rates of 64% to 100%, with CR rates of up to 50%.16 Variations on this regimen have shown that a slightly decreased cyclophosphamide dose improves the safety profile of the regimen without compromising efficacy, and that results were similar with concurrent or sequential administration of the two therapies.16 The addition of mitoxantrone to FC in 37 patients with relapsed/refractory CLL produced a high CR rate (50%), including 10 cases of MRD negativity, with a median duration of response of 19 months.9 All MRDnegative patients were alive at analysis. The median duration of response had not been reached in the CR patients compared to 25 months in non-CR patients. A Phase II study of cladribine in combination with cyclophosphamide has also been seen to be active in advanced CLL, but the results seemed inferior to those of FC.20 In a prospective trial of the German CLL study group (GCLLSG) comparing fludarabine versus FC, results for 375 patients showed superior response rates for the combination.3 The FC combination chemotherapy resulted in a significantly higher complete remission rate (16%) and overall response rate (94%) compared to fludarabine alone (5% and 83%; p=0.004 and 0.001 respectively). The FC treatment also resulted in a longer median duration of response (48 vs. 20 months; p=0.001), and a longer event-free survival (49 vs. 33 months; p=0.001). So far, no difference in the median overall survival could be observed within a median observation period of 22 months. FC caused significantly more thrombocytopenia and neutropenia, but less anemia than fludarabine. FC did not increase the number of severe infections3 (Table 2). Two additional phase III trials have confirmed these findings. The American study21 has included 278 previously untreated patients with CLL randomly Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 123 | 12th Congress of the European Hematology Association Table 2. Summary of recent major randomized trials for advanced chronic lymphocytic leukemia in treatment-naïve patients. Study n CR (%) PR (%) Response Duration Survival (median, months) (median, months) Rai12 Fludarabine Chlorambucil 170 181 20 4 43 33 25 14 66 56 Johnson13 Fludarabine CAP 52 48 23 17 48 43 NR 6.9 60% at 4 years 60% at 4 years Leporrier14 Fludarabine CAP CHOP 341 240 305 40.1 15.2 29.6 31 43 41.9 31.7 27.7 29.5 69 70 67 Robak56 Cladribine + prednisone Chlorambucil + prednisone 126 103 47 12 40 45 21 18 78% at 2 years 82% at 2 years Eichhorst3 Fludarabine Fludarabine, cyclophosphamide 182 180 4.9 16.5 78 78 20 48 Median not reached Median not reached Flinn21 Fludarabine Fludarabine, cyclophosphamide 137 141 4.6 23.4 59.5 50.9 19.2 31.6 79% at 2 years 80% at 2 years Robak23 Cladribine Cladribine, cyclophosphamide Cladribine, cyclophosphamide, mitoxantrone 166 162 151 21 29 36 56 54 44 23.5 22.4 23.6 51.2 Median not reached Median not reached O’Brien24 Fludarabine, cyclophosphamide Fludarabine, cyclophosphamide, oblimersen 121 120 7* 17* ND ND ND ND 32.9 33.8 CAP,cyclophosphamide, doxorubicin, prednisone; CHOP, cyclophosphamide, doxorubicin, vincristine, prednisone; CR, complete response; PR, partial response; NR, not reached. Please note that the response definitions varied considerably among the 4 trials. In the study by Leporrier et al.,14 a systematic evaluation of the bone marrow was not performed routinely to confirm a CR. Thus, the CR rates are somewhat higher than in the other trials. *included nPRs. ND = not determined. assigned to receive either fludarabine 25 mg/m2 intravenously (IV) days 1 through 5 or cyclophosphamide 600 mg/m2 IV day 1 and fludarabine 20 mg/m2 IV days 1 through 5. These cycles were repeated every 28 days for a maximum of six cycles. Treatment with fludarabine and cyclophosphamide was associated with a significantly higher complete response (CR) rate (23.4% v 4.6%; p<0.001) and a higher overall response (OR) rate (74.3% v 59.5%, p=0.013) than treatment with fludarabine as a single agent. Progression-free survival (PFS) was also superior in patients treated with fludarabine and cyclophosphamide than those treated with fludarabine (31.6 v 19.2 months, p<0.0001). Fludarabine and cyclophosphamide caused additional hematologic toxicity, including more severe thrombocytopenia (p=0.046), but it did not increase the number of severe infections (p=0.812).21 The UK study was presented at the American Society of Hematology Meeting in 2005 and has shown very similar results.22 Finally, the Polish study group compared 2-CdA alone to 2-CdA combined with cyclophosphamide (CC) or to cyclophosphamide and mitoxantrone (CMC) in 479 cases with untreated progressive CLL.23 Surprisingly, the CC combination therapy did not produce any benefit in terms of progression free sur- vival or response rates when compared to 2-CdA alone. Compared with 2-CdA, CMC induced a higher CR rate (36% vs 21%, p=0.004), and a trend for a higher CR rate with CC was observed (29% vs 21%, p=0.08). Furthermore, the percentage of patients who were in CR and were MRD negative was higher in the CMC arm compared with 2-CdA (23% vs 14%, p=0.042). There were no differences in overall response, progression-free survival, and overall survival among treatment groups. Grade 3/4 neutropenia occurred more frequently in CC (32%) and CMC (38%) than in 2-CdA (20%) (p=0.01 and p=0.004, respectively). Infections were more frequent in CMC compared with 2-CdA (40% vs 27%, p=0.02). Based on these results, cladribine combination therapies do not seem to offer any advantage when used as first line treatment for CLL (Table 2). Finally, Susan O’Brien and her colleagues examined the effect of oblimersen, an anti-Bcl2 antagonist, when added to the FC regimen in a study on 241 patients. Fludarabine 25 mg/m2/d plus cyclophosphamide 250 mg/m2/d were administered intravenously for 3 days with or without oblimersen 3 mg/kg/d as a 7-day continuous intravenous infusion (beginning 4 days before chemotherapy) for up to six cycles. CR/nPR was achieved in 20 (17%) out of 120 | 124 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 3. Efficacy of combination regimens using fludarabine plus concurrent monoclonal antibodies in chronic lymphocytic leukemia in Phase II trials. Reference Fludarabine + rituximab Schulz28 Byrd29 (Phase III) randomized No. of evaluable patients 31 104 Stage Prior therapy no. Treatment regimen 100% Binet B or C Yes 20; No 11 FLU 25 mg/m2 d1-5 q 4 wk rituximab 375 mg/m2 d1 q4wk Rai I/II 59% Rai III/IV 41% No FLU 25 mg/m2 d1-5 q4wk rituximab 375 mg q 4 wk concurrent vs. sequential Yes FLU 25 mg/m2 d1-3 q4wk CYC 250 mg/m2 d1-3 q4wk rituximab* 375/500 mg/m2 d1 q4wk FLU 25 mg/m2 d1-3 q4wk CYC 250 mg/m2 d1-3 q4wk rituximab 375 mg/m2 d1 q4wk Fludarabine + cyclophosphamide + rituximab 177 Rai IV 44% Wierda57 Keating31 224 Fludarabine + alemtuzumab Kennedy39 6 Elter40 36 Rai III + IV 33% No Binet B 50% Binet C 50% Binet B 24% Binet C 76% Yes Yes CR Clinical response CR + PR 32% 87% Survival/duration of response Median survival 33 mths; median duration of response 75 weeks 47% concurrent 90% concurrent After 23 months median 28% sequential 77% sequential duration of response not yet reached in both arms 25% 73% Median survival 42 months; median time to progression 28 months 70% 95% 69% failure free at 4 years FLU 25 mg/m2 d1-3 q4wk 17% alemtuzumab 30 mg tiw 8-16 wk FLU 25 mg/m2 d1-3 q4wk 30% alemtuzumab 30 mg d1-3 q4wk 83% 83% survival after 12 months n.a. 83% CR: complete response; CYC: cyclophosphamide; FLU: fludarabine; PR: partial response. *rituximab 375 mg/m2 course 1, 500 mg/m2 all subsequent courses. patients in the oblimersen group and eight (7%) of 121 patients in the chemotherapy-only group (p= 0.025). Achievement of CR/nPR was correlated with both an extended time to progression and survival (p <0.0001). However, the overall survival and the progression-free survival did not show any difference indicating that oblimersen did not strongly improve the efficacy of the FC regimen.24 Rituximab-based chemo-immunotherapy Rituximab, an anti-CD20 monoclonal antibody, has only recently provoked interest for the treatment of CLL. As a single agent rituximab is less active than in follicular lymphoma, unless very high doses are used.25,26 Somewhat surprisingly, combinations of rituximab with chemotherapy have proven to be very effective in CLL. There is preclinical evidence for synergy between rituximab and fludarabine.27 The majority of rituximab combination studies in CLL have focused on combinations with fludarabine or fludarabine-based regimens (Table 3). A multicenter Phase II study of the German CLL study group has evaluated the efficacy and safety of rituximab plus fludarabine in patients with previously treated or untreated CLL.28 Of 31 patients treated, 27 (87%) responded, with 10 patients (32%) achieving a complete response. Byrd and colleagues combined rituximab with fludarabine in either a sequential or concurrent regimen in a randomized study (CALGB 9712 protocol).29 Patients (n=104) with previously untreated CLL received six cycles of fludarabine, with or without rituximab, followed by four once-weekly doses of rituximab. Overall and complete response rates were higher in the concurrent regimen group (90% and 47% vs. 77% and 28%). More recently, in a retrospective analysis, all patients under the CALGB 9712 protocol treated with fludarabine and rituximab were compared with 178 patients from the previous CALGB 9011 trial, who received only fludarabine.30 The basic characteristics of patients were comparable, except for an 8year longer observation time in the CALGB 9011 protocol. The patients receiving fludarabine and rituximab had a better progression-free survival (PFS) and overall survival (OS) than patients receiving fludarabine alone. Two-year PFS probabilities were 67% versus 45% and 2-year OS probabilities were 93% versus 81%. Similarly, in a large Phase II trial conducted at the MD Anderson Cancer Center on 224 patients with previously untreated CLL, rituximab plus fludarabine/cyclophosphamide (FC) achieved a response rate of 95% with 71% complete responses.31 Median overall survival was not reached in patients treated Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 125 | 12th Congress of the European Hematology Association with rituximab plus FC, and was significantly longer than in patients treated with FC alone in an historical comparison (Table 3). Taken together, these results suggest that rituximab plus fludarabine-based therapies represent a significant advance in therapy for CLL. However, the analysis by Byrd and colleagues is retrospective and could be confounded by differences in supportive care or different prognostic subsets included in the two trials. Therefore, these findings need to be confirmed by prospective trials. The results from the GCLLSG CLL8 trial comparing FC to FCR are expected next year. Alemtuzumab-based chemo-immunotherapy Alemtuzumab is a recombinant, fully humanized, monoclonal antibody against the CD52 antigen. Monotherapy with alemtuzumab has produced response rates of 33% to 53%, with a median duration of response ranging from 8.7 to 15.4 months in patients with advanced CLL who were previously treated with alkylating agents and had failed or relapsed after second-line fludarabine therapy.32-34 In addition, alemtuzumab has proven effective even in patients with poor prognostic factors, including highrisk genetic markers such as deletions of chromosome 11 or 17 and p53 mutations.35,36 If these results are confirmed in larger, prospective trials, alemtuzumab might be a rational choice for first-line treatment of patients with these poor prognostic factors. Alemtuzumab consolidation therapy after fludarabine-based chemotherapy also improved the quality of response, achieved molecular remissions in a substantial proportion of patients, and increased PFS compared with patients who had no further treatment.8,37,38 Results of a Phase III trial by the GCLLSG showed improved PFS with alemtuzumab consolidation therapy compared to the observation arm (no progression vs. 24.7 months, p=0.036) when calculated from the start of fludarabine-based treatment0.8 When PFS was calculated from the date of alemtuzumab administration, the same benefit was apparent, with no progression compared to 17.8 months (p=0.036). O’Brien and colleagues reported an overall response rate of 53%, in 9 out of 23 patients (39%) at a 10 mg dose and 17 out of 26 (65%) at a 30 mg dose (p=0.066)0.38 Residual disease was cleared from the bone marrow in most patients, and 11 (38%) of the 29 patients with available data achieved a molecular remission. Median time to disease progression had not yet been reached for patients who achieved MRD negativity, compared to 15 months for patients who still had residual disease after alemtuzumab consolidation treatment.38 While the GCLLSG trial was stopped early because of infectious adverse events, this was not the case in the study by O’Brien et al. This was perhaps due to a longer time interval between induction therapy and consolidation with alemtuzumab (6 months versus 3 months in the GCLLSG study). Perhaps the most potent regimen for CLL is the combination of the most effective single chemotherapeutic agent with the most effective monoclonal antibody fludarabine plus alemtuzumab (Table 3). The synergistic activity of these two agents was initially suggested by the induction of responses, including one CR, in 5 out of 6 patients who were refractory to each agent alone.39 The combination of fludarabine and alemtuzumab was investigated in a Phase II trial enrolling patients with relapsed CLL (Table 3).40 Using a four-weekly dosing protocol, this combination has proven feasible, safe, and very effective. Among the 36 patients, the ORR was 83% (30/36 patients), which included 11 CRs (30%) and 19 PRs (53%). In addition, one patient achieved stable disease. Sixteen out of 31 (53%) evaluated patients achieved MRD negativity in the peripheral blood by 3 months’ follow-up, and resolution of disease was observed in all disease sites, particularly in the blood, bone marrow and spleen. The fludarabine/alemtuzumab combination therapy was well tolerated. Infusion reactions (fever, chills, and skin reactions) occurred primarily during the first infusions of alemtuzumab, and were mild in the majority of patients. While 80% of patients were cytomegalovirus immunoglobulin G (CMV IgG)-positive before treatment, there were only two subclinical CMV reactivations. The primary grade 3/4 hematological events were transient, including leukocytopenia (44%) and thrombocytopenia (30%). Stable CD4+ T-cell counts (> 200/µL) were seen after 1 year. A Phase III prospective randomized study evaluating the effectiveness of fludarabine and alemtuzumab combination in comparison with fludarabine alone is currently underway. The combination of both monoclonal antibodies (alemtuzumab and rituximab) has been studied in patients with lymphoid malignancies, including those with refractory/relapsed CLL, producing an ORR of 52% (8% CR; 4% nodular PR, nPR; 40% PR).41 A larger trial with a longer follow-up is needed to confirm these preliminary results and determine the long-term efficacy of this combination. Conclusions Treatment of CLL in first line Given the potential of the chemoimmunotherapy regimens described above, choosing the right treatment for a patient with CLL has become a task that requires skill and experience. Table 4 proposes an algorithm for the selection of the best treatment option, which is based on three potentially relevant considerations. a) Patient physical condition (fitness | 126 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 4. Summary of the current options for first second line treatment in CLL. Binet stage Fitness First line treatment GCLLSG trialk A, asymptomatic B Irrelevant None CLL7 (FCR at high risk?) C, symptomatic B Go Go Slow Go FCR, FC CLB, F (reduced dose) CLL8 CLL9 Relapse Fitness Second line GCLLSG trial Early (<1 year) = refractory disease GoGo Slow Go Allo Tx Alemtuzumab (17p-) Bendamustin, R-CHOP CLL3X CLL2G, CLL2M Late(>1 year) Go Go & Slow Go Repeat first line and comorbidity) is independent of calendar age; b) the prognostic risk of the leukemia as determined by the factors mentioned above; c) Rai or Binet disease stage Patients at early stage (Binet A and B without symptoms) should not be treated outside clinical trials. Treatment may be indicated in clinical trials in patients at high risk of disease progression. Patients with advanced disease (Binet C, or symptomatic stage A or B) should start treatment. In this situation, patients need to be evaluated for their physical condition (or comorbidity). For patients in good physical condition (go go) as defined by a normal creatinine clearance and a low score at the cumulative illness rating scale (CIRS),42 patients should be offered more combination therapies such as FC or FR or FCR. Patients with an impaired physical condition (slow go) may be offered either chlorambucil or a dose-reduced fludarabine monotherapy for symptom control. Patients with symptomatic disease and with del(17p) or p53 mutations should receive an alemtuzumab-containing regimen as first-line treatment, because these patients respond poorly to fludarabine or fludarabine-cyclophosphamide. Treatment for relapsed or refractory disease While an extensive review of all treatment options for relapsed or refractory CLL is beyond the scope of this paper, Table 4 summarizes some principles of the management of patients at relapse according to the duration of remission and the physical fitness. In general, first-line treatment may be repeated, if the duration of the first remission exceeds 12 months (or with the modern chemoimmunotherapies, 24 months). The choice becomes more difficult and limited in treatment-refractory CLL (as defined by an early relapse within 12 months after the last treatment) or in cases with the chromosomal aberration del(17p). In principle, the initial regimen should be changed. There options are: Alemtuzumab alone or in combination.33,40 Flavopiridol (if available).43 Allogeneic stem cell transplantation with curative intent.44 The choice of one of these options depends on the fitness of the patient, the availability of drugs and the molecular cytogenetics. Physically fit patients with a del(17p) should be offered an allogeneic transplantation, since their prognosis remains poor with conventional therapies. The EMBT consensus has defined criteria for including patients in allogeneic transplantation protocols.44 Finally, it is important to emphasize that all patients with refractory disease should be treated within clinical trials whenever possible. References 1. Rai KR, Sawitsky A, Cronkite EP, Chanana AD, Levy RN, Pasternack BS. Clinical staging of chronic lymphocytic leukemia. Blood 1975;46:219-34. 2. Binet JL, Auquier A, Dighiero G, et al. A new prognostic classification of chronic lymphocytic leukemia derived from a multivariate survival analysis. Cancer 1981;48:198-204. 3. Stilgenbauer S, Kröber, Busch R, et al. 17p Deletion Predicts for Inferior Overall Survival after Fludarabine - Based First Line Therapy in Chronic Lymphocytic Leukemia: First Analysis of Genetics in the CLL4 Trial of the GCLLSG. Blood (ASH Annual Meeting Abstracts). 2005;106:715. 4. Grever MR, Lucas DM, Dewald GW, et al. Comprehensive assessment of genetic and molecular features predicting outcome in patients with chronic lymphocytic leukemia: results from the US Intergroup Phase III Trial E2997. J Clin Oncol 2007;25:799-804. 5. Cheson BD, Bennett JM, Grever M, et al. National Cancer Institute-Sponsored Working Group guidelines for chronic lymphocytic leukemia: revised guidelines for diagnosis and treatment. Blood 1996;87:4990-7. 6. Rawstron AC, Villamor N, Ritgen M, et al. International standardized approach for flow cytometric residual disease monitoring in chronic lymphocytic leukaemia. Leukemia 2007. 7. Moreton P, Kennedy B, Lucas G, et al. Eradication of Minimal Residual Disease in B-Cell Chronic Lymphocytic Leukemia After Alemtuzumab Therapy Is Associated With Prolonged Survival. J Clin Oncol 2005;23:2971-9. 8. Wendtner CM, Ritgen M, Schweighofer CD, et al. Consolidation with alemtuzumab in patients with chronic lymphocytic leukemia (CLL) in first remission--experience on safety and efficacy within a randomized multicenter phase III trial of the German CLL Study Group (GCLLSG). Leukemia 2004;18:1093-101. 9. Bosch F, Ferrer A, Lopez-Guillermo A, et al. Fludarabine, cyclophosphamide and mitoxantrone in the treatment of resistant or relapsed chronic lymphocytic leukaemia. Br J Haematol 2002;119:976-84. 10. Anaissie EJ, Kontoyiannis DP, O'Brien S, et al. Infections in patients with chronic lymphocytic leukemia treated with fludarabine. Ann Intern Med. 1998;129:559-66. 11. Plunkett W, Gandhi V, Huang P, et al. Fludarabine: pharmacokinetics, mechanisms of action, and rationales for combination therapies. Semin Oncol 1993;20:2-12. 12. Rai KR, Peterson BL, Appelbaum FR, et al. Fludarabine compared with chlorambucil as primary therapy for chronic lymphocytic leukemia. N Engl J Med 2000;343:1750-7. 13. Johnson S, Smith AG, Loffler H, et al. Multicentre prospective randomised trial of fludarabine versus cyclophosphamide, doxorubicin, and prednisone (CAP) for treatment of advancedstage chronic lymphocytic leukaemia. The French Cooperative Group on CLL [see comments]. Lancet 1996;347: 1432-8. 14. Leporrier M, Chevret S, Cazin B, et al. Randomized comparison of fludarabine, CAP, and ChOP in 938 previously untreated stage B and C chronic lymphocytic leukemia patients. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 127 | 12th Congress of the European Hematology Association Blood 2001;98:2319-25. 15. Steurer M, Pall G, Richards S, Schwarzer G, Bohlius J, Greil R. Purine antagonists for chronic lymphocytic leukaemia. Cochrane Database Syst Rev 2006;3:CD004270. 16. Hallek M, Eichhorst BF. Chemotherapy combination treatment regimens with fludarabine in chronic lymphocytic leukemia. Hematol J. 2004;5 Suppl 1:S20-30. 17. O'Brien S, Kantarjian H, Cortes J, et al. Results of the fludarabine and cyclophosphamide combination regimen in chronic lymphocytic leukemia. J Clin Oncol 2001;19:1414-20. 18. Hallek M, Schmitt B, Wilhelm M, et al. Fludarabine plus cyclophosphamide for the treatment of chronic lymphocytic leukemia: Results of a phase II study (CLL2 protocol) of the German CLL Study Group (GCLLSG). Br J Haematol 2001; 114:342-8. 19. Flinn IW, Byrd JC, Morrison C, et al. Fludarabine and cyclophosphamide with filgastrim support in patients with previously untreated indolent lymphoid malignancies. Blood 2000;96:71-5. 20. Montillo M, Tedeschi A, O'Brien S, et al. Phase II study of cladribine and cyclophosphamide in patients with chronic lymphocytic leukemia and prolymphocytic leukemia. Cancer 2003;97:114-20. 21. Flinn IW, Neuberg DS, Grever MR, et al. Phase III trial of fludarabine plus cyclophosphamide compared with fludarabine for patients with previously untreated chronic lymphocytic leukemia: US Intergroup Trial E2997. J Clin Oncol 2007;25: 793-8. 22. Catovsky D, Richards S, Hillmen P. Early Results from LRF CLL4: A UK Multicenter Randomized Trial. ASH Annual Meeting Abstracts 2005;106:716. 23. Robak T, Blonski JZ, Gora-Tybor J, et al. Cladribine alone and in combination with cyclophosphamide or cyclophosphamide plus mitoxantrone in the treatment of progressive chronic lymphocytic leukemia: report of a prospective, multicenter, randomized trial of the Polish Adult Leukemia Group (PALG CLL2). Blood 2006;108:473-9. 24. O'Brien S, Moore JO, Boyd TE, et al. Randomized Phase III Trial of Fludarabine Plus Cyclophosphamide With or Without Oblimersen Sodium (Bcl-2 antisense) in Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia. J Clin Oncol 2007;25:1114-20. 25. Huhn D, von Schilling C, Wilhelm M, et al. Rituximab therapy of patients with B-cell chronic lymphocytic leukemia. Blood 2001;98:1326-31. 26. O'Brien S, Kantarijan H, Thomas D, et al. Rituximab doseescalation trial in chronic lymphocytic leukaemia. J Clin Oncol 2001;19:2165-70. 27. di Gaetano N, Xiao Y, Erba E, et al. Synergism between fludarabine and rituximab revealed in a follicular lymphoma cell line resistant to the cytotoxic activity of either drug alone. Br J Haematol 2001;114:800-9. 28. Schulz H, Klein SH, Rehwald U, et al. Phase II study of a combined immunochemotherapy using rituximab and fludarabine in patients with chronic lymphocytic leukemia. Blood 2002;100:3115-20. 29. Byrd JC, Peterson BL, Morrison VA, et al. Randomized phase 2 study of fludarabine with concurrent versus sequential treatment with rituximab in symptomatic, untreated patients with B-cell chronic lymphocytic leukemia: results from Cancer and Leukemia Group B 9712 (CALGB 9712). Blood 2003;101:6-14. 30. Byrd JC, Rai K, Peterson BL, et al. Addition of rituximab to fludarabine may prolong progression-free survival and overall survival in patients with previously untreated chronic lymphocytic leukemia: an updated retrospective comparative analysis of CALGB 9712 and CALGB 9011. Blood 2005; 105:49-53. 31. Keating MJ, O'Brien S, Albitar M, et al. Early results of a chemoimmunotherapy regimen of fludarabine, cyclophosphamide, and rituximab as initial therapy for chronic lymphocytic leukemia. J Clin Oncol 2005;23:4079-88. 32. Österborg A, Dyer MJ, Bunjes D, et al. Phase II multicenter study of human CD52 antibody in previously treated chronic lymphocytic leucemia. European study group of CAMPATH1H treatment in chronic lymphocytic leukemia. J Clin Oncol 1997;15:1567-74. 33. Rai KR, Freter CE, Mercier RJ, et al. Alemtuzumab in previously treated chronic lymphocytic leukemia patients who also had received fludarabine. J Clin Oncol 2002;20:3891-7. 34. Keating MJ, Flinn I, Jain V, et al. Therapeutic role of alemtuzumab (Campath-1H) in patients who have failed fludarabine: results of a large international study. Blood 2002;99: 3554-61. 35. Stilgenbauer S, Dohner H. Campath-1H-induced complete remission of chronic lymphocytic leukemia despite p53 gene mutation and resistance to chemotherapy. N Engl J Med 2002;347:452-3. 36. Lozanski G, Heerema NA, Flinn IW, et al. Alemtuzumab is an effective therapy for chronic lymphocytic leukemia with p53 mutations and deletions. Blood 2004;103:3278-81. 37. Montillo M, Cafro AM, Tedeschi A, et al. Safety and efficacy of subcutaneous Campath-1H for treating residual disease in patients with chronic lymphocytic leukemia responding to fludarabine. Haematologica. 2002;87:695-700; discussion 700. 38. O'Brien SM, Kantarjian HM, Thomas DA, et al. Alemtuzumab as treatment for residual disease after chemotherapy in patients with chronic lymphocytic leukemia. Cancer 2003; 98:2657-63. 39. Kennedy B, Rawstron A, Carter C, et al. Campath-1H and fludarabine in combination are highly active in refractory chronic lymphocytic leukemia. Blood 2002;99:2245-7. 40. Elter T, Borchmann P, Schulz H, et al. Fludarabine in combination with alemtuzumab is effective and feasible in patients with relapsed or refractory B-cell chronic lymphocytic leukemia: results of a phase II trial. J Clin Oncol 2005;23:702431. 41. Faderl S, Thomas DA, O'Brien S, et al. Experience with alemtuzumab plus rituximab in patients with relapsed and refractory lymphoid malignancies. Blood. 2003;101:3413-15. 42. Extermann M, Overcash J, Lyman GH, Parr J, Balducci L. Comorbidity and functional status are independent in older patients. J Clin Oncol 1998;16:1582-7. 43. Byrd JC, Lin TS, Dalton JT, et al. Flavopiridol administered using a pharmacologically derived schedule is associated with marked clinical efficacy in refractory, genetically high-risk chronic lymphocytic leukemia. Blood. 2007;109:399-404. 44. Dreger P, Corradini P, Kimby E, et al. Indications for allogeneic stem cell transplantation in chronic lymphocytic leukemia: the EBMT transplant consensus. Leukemia 2007;21:12-7. 45. Döhner H, Stilgenbauer S, Benner A, et al. Genomic aberrations and survival in chronic lymphocytic leukemia. N Engl J Med 2000;343:1910-6. 46. Rassenti LZ, Huynh L, Toy TL, et al. ZAP-70 compared with immunoglobulin heavy-chain gene mutation status as a predictor of disease progression in chronic lymphocytic leukemia. N Engl J Med 2004;351:893-901. 47. Crespo M, Bosch F, Villamor N, et al. ZAP-70 expression as a surrogate for immunoglobulin-variable-region mutations in chronic lymphocytic leukemia. N Engl J Med 2003; 348: 1764-75. 48. Damle RN, Wasil T, Fais F, et al. Ig V gene mutation status and CD38 expression as novel prognostic indicators in chronic lymphocytic leukemia [see comments]. Blood 1999;94:1840-7. 49. Ibrahim S, Keating M, Do KA, et al. CD38 expression as an important prognostic factor in B-cell chronic lymphocytic leukemia. Blood 2001;98:181-6. 50. Montserrat E, Sanchez BJ, Vinolas N, Rozman C. Lymphocyte doubling time in chronic lymphocytic leukaemia: analysis of its prognostic significance. Br J Haematol 1986;62:567-75. 51. Keating MJ, Lerner S, Kantarjian H, Freireich EJ, O'Brien S. The serum ß2-microglobulin (ß2m) level is more powerful than stage in predicting response and survival in chronic lymphocytic leukemia (CLL). Blood 1995;86 (Suppl. I):606a. 52. Reinisch W, Willheim M, Hilgarth M, et al. Soluble CD23 reliably reflects disease activity in B-cell chronic lymphocytic leukemia. J Clin Oncol 1994;12:2146-9. 53. Sarfati M, Chevret S, Chastang C, et al. Prognostic importance of serum soluble CD23 level in chronic lymphocytic leukemia. Blood. 1996;88:4259-64. 54. Hallek M, Langenmayer I, Nerl C, et al. Elevated serum thymidine kinase levels identify a subgroup at high risk of diseaseprogression in early, non-smoldering chronic lymphocytic leukemia. Blood. 1999;93:1732-7. 55. Hamblin TJ, Davis Z, Gardiner A, Oscier DG, Stevenson FK. Unmutated Ig V(H) genes are associated with a more aggressive form of chronic lymphocytic leukemia [see comments]. Blood 1999;94:1848-54. 56. Robak T, Blonski JZ, Kasznicki M, et al. Cladribine with prednisone versus chlorambucil with prednisone as first- line therapy in chronic lymphocytic leukemia: report of a prospective, randomized, multicenter trial. Blood 2000;96:2723-9. 57. Wierda W, O'Brien S, Wen S, et al. Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab for relapsed and refractory chronic lymphocytic leukemia. J Clin Oncol 2005;23:4070-8. | 128 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Chronic Lymphocytic Leukemia New drugs for chronic lymphocytic leukemia A J. Gribben Institute of Cancer, Barts and The London School of Medicine, University of London, United Kingdom Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:129-133 B S T R A C T Recently there has been an improvement in response rates in patients with chronic lymphocytic leukemia (CLL) using combination chemotherapy and chemoimmunotherapy, most commonly with rituximab or alemtuzumab. After relapse, retreatment is more difficult in patients who have received combination chemoimmunotherapy and is particularly difficult once patients become refractory to fludarabine, and new agents are needed. Ongoing clinical trials are investigating the role of new agents, including alternative nucleoside analogs, monoclonal antibodies, novel agents including lenalidomide and flavopirodol, signal transduction inhibitors/small molecules targeting novel pathways capable of overcoming the failure of apoptosis in CLL cells. he outcome of patients with CLL is improving with the use of combination chemotherapy1,2 and chemoimmunotherapy3and the use of purine analog combinations have resulted in the highest response rates observed to date in CLL. Most studies have used fludarabine while, similar responses have been seen with pentostatin.4 Although an early report noted responses to cladribine in patients with fludarabine-refractory CLL5 this has not been confirmed in later studies which also demonstrated considerable toxicity from cladribine due to myelosuppression and infections.6 Trials with the novel purine analog clofarabine, administered daily for five days, demonstrated minimal activity in CLL.7 Therefore, there is no evidence to support the use of an alternative nucleoside analog in fludarabine-refractory CLL. Once patients relapse after combination chemoimmunotherapy, and particularly as they become resistant to fludarabine, there are few therapeutic options available. Alemtuzumab is the only drug currently licensed for use in fludarabine refractory CLL following an important demonstrating improved survival in this setting.8 There is clearly a need for additional agents with activity in this disease New drug development in CLL has been seriously compromised both by the lack of suitable cell lines derived from T patients with CLL as well as appropriate animal models of the disease. The EµTCL1 mouse develops a B cell lymphoproliferative disorder resembling CLL9 and although there are concerns regarding how accurately the model reflects the human disease, CLL cells in the Eµ-TCL1 mouse model express relevant therapeutic targets including anti-apoptotic proteins, survival kinases and DNA methlytrasferases. Specifically, the TCL-1 leukemia cells express BCL-2, MCL-1 and DNMT1, with corresponding phosphorylation of AKT and PDK1 and also demonstrate similar in vitro and in vivo sensitivity to agents including fludarabine, flavopiridol and OSU03012 and resistance to paclitaxel, as occurs in the human disease.10 Therefore, this model has sufficient clinical and therapeutic similarities to human CLL to suggest exciting new opportunities to screen new drugs and novel combinations in vivo and speed therapeutic development in this still incurable disease. Targeting anti-apoptotic pathways in CLL Over-expression of BCL-2 in CLL is associated with chemotherapy resistance and decreased survival and inhibition of this antiapoptotic proteins is an attractive strategy for either restoring normal apoptotic process in CLL cells or making them more susceptible to conventional chemo- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 129 | 12th Congress of the European Hematology Association therapy. A number of agents are under investigation which target not only BCL-2, but also other antiapoptotic proteins in CLL cells. Oblimersen is an antisense oligonucleotide compound designed to bind to the first six codons of human BCL-2 mRNA, resulting in degradation of subsequent decrease in Bcl-2 protein translation. Studies have investigated the role of this agent in improving responses to chemotherapy in patients with relapsed or refractory CLL. Twohundredandforty-one patients were randomly assigned to 28-day cycles of fludarabine plus cyclophosphamide (FC) with or without oblimersen 3 mg/kg/d as a 7-day continuous intravenous infusion (beginning 4 days before chemotherapy) for up to six cycles. Complete remission (CR) or nodular partial remissions (nPR) were achieved in 17% of the oblimersen group but only 7% of the chemotherapy-only group (p=0.025) and those patients who achieved CR/nPR had increased time to progression and survival (p<0.0001).11 This was particularly the case in those patients who remained fludarabine sensitive. The major toxicity was thrombocytopenia and, rarely, tumor lysis syndrome and cytokine release reactions. The incidence of opportunistic infections and second malignancies was similar in both groups. Novel agents specifically targeting anti-apoptotic proteins include the pan-BCL-2 inhibitor GX15-070 which mimics BH3-only proteins by binding to multiple antiapoptotic BCL-2 members. A number of agents targeting these pathways are in pre-clinical development. It is also clear that a number of agents that are thought to target other pathways, also mediate at least some of their effect by alteration of the balance of pro-and anti-apoptotic proteins in malignant cells, including the proteosome inhibitor bortezomib. Although this agent has impressive activity in a number of B cell malignancies, disappointing response rates were observed in a clinical trial in CLL.12 Lenalidomide There is increasing interest in agents that target the tumor-cell microenvironment. Immunomodulating agents alter cytokine expression, co-stimulate immune effector cells, and have direct and indirect effects upon CLL cells. Lenalidomide is a synthetic analog of thalidomide and while its mechanism of action is uncertain, lenalidomide downregulates tumor necrosis factor-α and enhances antibodydependent cytotoxicity. Significant activity of lenalidomide has been observed in both 5qmyelodysplasia and multiple myeloma and now also in CLL.13 In a study of CLL patients, lenalidomide was administered orally at 25 mg on days 1 through to 21 of a 28-day cycle and patients continued treat- ment until disease progression, unacceptable toxicity, or complete remission. Rituximab could be added to lenalidomide on disease progression. Forty-five patients were enrolled, 51% refractory to fludarabine. Overall response was 47%, with 9% of patients attaining CR. The most common adverse effects were fatigue, thrombocytopenia, and neutropenia. Lenalidomide is clinically active in patients with relapsed or refractory B-CLL and is under investigation in ongoing clinical trials. Flavopiridol Flavopiridol is a synthetic flavone that inhibits CDK1, CDK2, CDK4 and other kinases, including cyclin-dependent kinase 9, leading to inactivation of RNA polymerase II and global inhibition of gene transcription. Flavopiridol induces apoptosis in CLL cells in vitro at concentrations attainable in the clinic and induces apoptosis in CLL cells by activating caspase 3. Importantly, induction of apoptosis by flavopiridol occurred in a p53 independent manner. It is likely that alternative mechanisms of action are also involved in producing flavopiridol’s rapid cytotoxic effect on CLL cells in vivo. A variety of different schedules of administration have been explored with flavopiridol, including 72-hour continuous infusion, 24-hour continuous infusion, and 1-hour bolus. The 24-hour infusion schedule was examined at two doses in 28 patients and no clinical responses were noted.14 Pharmakinetic modeling studies at Ohio State University suggested that a 30-minute bolus followed by a 4-hour CI schedule could provide a sufficient concentration of flavopiridol to induces apoptosis in primary CLL cells. In a subsequent clinical trial 42 patients were enrolled in 3 cohorts. Cohort 1 was treated at 30 mg/m2 loading dose followed by 30 mg/m2 4-hour infusion, cohort 2 at 40 mg/m2 loading dose followed by 40 mg/m2 4hour infusion, and cohort 3 at cohort 1 dose for treatments 1 to 4, then a 30 mg/m2 loading dose followed by a 50 mg/m2 4-hour infusion. The dose-limiting toxicity was hyperacute tumor lysis syndrome, which may be prevented by aggressive prophylaxis and exclusion of patients with high white blood counts. Of the 42 patients treated, 45% achieved a PR and responses were noted in patients with del 17p13 and del 11q22, justifying a further study of flavopiridol in CLL and other diseases. In addition, other studies with flavopiridol, both to eliminate minimal residual disease and in combination with other agents, are being developed. Monoclonal antibodies Alemtuzumab is the only monoclonal antibody currently licensed for use in CLL and is licensed for fludarabine refractory CLL following a pivotal trial | 130 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 demonstrating improved survival in this setting.8 Alemtuzumab is being investigated as consolidation therapy to eradicate minimal residual disease.15,16 There have been concerns regarding the safety of this approach17 and ongoing studies are examining the optimal timing, duration and route of administration of this agent as consolidation. Alemtuzumab has been investigated in combination with fludarabine,18 and with rituximab.19 Despite its impressive activity in B cell nonHodgkin’s lymphoma, the activity of rituximab as a single agent in CLL is modest when rituximab is used at the standard 375 mg/m2 weekly for 4 to 8 weeks as for lymphoma, but does have increased activity at higher doses or with increased frequency of scheduling.20,21 Patients with del 17p did not respond to rituximab monotherapy.22 Most interest in rituximab is in its potential synergistic activity with chemotherapy, including fludarabine alone,23 FC,3 or pentostatin and cyclophosphamide.4 Ongoing randomized trials will demonstrate whether the addition of rituximab to chemotherapy is associated with improved response rates, durations of response and overall survival. Rituximab is also being investigated as monotherapy in early stage disease in the elderly and in combination with chlorambucil, lenalidomide and bortezomib. Since CD23 expression is a characteristic feature of CLL cells, the anti-CD23 antibody lumiliximab is of interest and is being investigated in combination with chemotherapy and rituximab. HuMax-CD20 is the first fully human monoclonal antibody and targets a different epitope of the CD20 molecule expressed by B cells and is currently in clinical trials. Other monoclonal antibodies of interest in CLL include anti-CD40. CHIR-12.12 is a fully humanized anti-CD40 monoclonal antibody that blocks interaction with CD40 ligand, thereby preventing an antiapoptotic stimulus to CLL cells. Based on a promising clinical study, successful xenograft lymphoma studies, and acceptable toxicity in vivo, a phase I study of CHIR-12.12 has recently been initiated in relapsed and refractory CLL. SGN40 is another fully humanized CD40 directed antibody that does not block interaction with CD40. Preclinical studies with SGN40 are underway both as a single agent and in combination with other biologic therapies. Tru 16.4 is a single-chain protein with a modified CD37 binding Fv domain linked to a modified human IgG1 hinge, CH2 and CH3 domains, and is a member of a novel composition class called small modular immunopharmaceuticals (SMIPs). Preclinical studies with Tru 16.4 demonstrated that it binds to CD37 on primary CLL cell surface and induces caspase-independent apoptosis. Further modifications of Tru16.4 are underway to enhance ADCC mechanisms. Hu1D10 is a humanized mon- oclonal antibody that targets a β-chain epitope of HLA-DR and induces apoptosis via a novel pathway. Up to 70% of patients express this antigen on their CLL cells. A phase I trial administering this agent three times a week in CLL patents has been completed with clinical responses noted, including patients with del 17p13 and a phase II study is underway in fludarabine-refractory CLL. Combination studies with Hu1D10 and granulocyte colony-stimulating factor and Hu1D10 and rituximab are also ongoing. Additionally, there are other broad HLA-DR–directed antibodies that are currently being considered for clinical trials. Small molecules in CLL Increased understanding of CLL pathophysiology has led to the investigation of a variety of targeted therapies directed at specific signal transduction pathways. Many of these either have preclinical rationale or have been demonstrated to have preclinical activity in CLL and merit further investigation. Notable among these agents are 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) and 17-dimethylaminoethylamino-17-demethoxygeldanamycin (DMAG) that inhibit function of activated heat shock protein 90 (hsp90), thus preventing chaperoning of client proteins including AKT and ZAP70 in CLL cells..25 The nutlins are smallmolecule activators of p53 that have been developed and who inhibit binding of p53 to MDM2. Nutlin-3 stabilized p53, induced p53 target genes and synergized with chemotherapy, suggesting that MDM2 antagonists alone or in combination with chemotherapy may have potential in CLL.26 Of note, nutlin-3 activates the p53 pathway and effectively induces apoptosis in cells with dysfunctional ATM, but not mutant p53. Other agents Protein kinase C inhibitors including UCN-01 (27) and PKC412,28 and alternative cyclin-dependent kinase inhibitors including Roscovitine,29 may also be promising in CLL. Chromatin remodeling agents which have been studied include the histone deacetylase inhibitors depsipeptide30 and MS275,31 as well as decitabine, which inhibits DNA methyltransferase which has shown promise in preclinical testing. Other agents including epigallocatechin-3 gallate (EGCG)32 have shown promising preclinical activity and are entering clinical trials. R-etodolac (SDX-101) is an isoform of the non-steroidal anti-inflammatory drug etodolac which shows activity against CLL cells33 and is currently being tested in phase II clinical trials for the treatment of refractory B-cell. Deletion and dysfunction of p53 in CLL are associated with poor response to chemotherapy and Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 131 | 12th Congress of the European Hematology Association poor outcome. Corticosteroids have long been recognized to have activity in CLL, and recent studies have focused on the use of high dose methylprednisolone to induce response in patients with p53 dysfunction.24 When high-dose corticosteroids are used for the treatment of CLL, it is necessary to administer antibiotic and antiviral prophylaxis and to monitor patients closely. High dose methylprednisolone is being investigated in combination with monoclonal antibodies including rituximab and alemtuzumab and, in particular, the combination of alemtuzumab and high dose corticosteroids appears attractive to target CLL cells with dysfunctional p53. Future directions After many years in which few agents showed documented activity in CLL, there is increased interest in the development of agents that target specific pathways. These agents have often been chosen on the basis of a fuller understanding of the underlying pathophysiology of CLL and selected for further study according to their preclinical activity. The potential role of novel agents in CLL will be dependent upon the results of ongoing clinical trials and the subsequent use of these agents will probably be dependent upon particular agents showing activity in subsets of patients with specific genetic risk factors. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. References 1. Eichhorst BF, Busch R, Hopfinger G, Pasold R, Hensel M, Steinbrecher C, et al. Fludarabine plus cyclophosphamide versus fludarabine alone in first-line therapy of younger patients with chronic lymphocytic leukemia. Blood 2006;107:885-91. 2. Grever MR, Lucas DM, Dewald GW, Neuberg DS, Reed JC, Kitada S, et al. Comprehensive assessment of genetic and molecular features predicting outcome in patients with chronic lymphocytic leukemia: results from the US Intergroup Phase III Trial E2997. J Clin Oncol 2007;25:799-804. 3. Keating MJ, O'Brien S, Albitar M, Lerner S, Plunkett W, Giles F, et al. Early results of a chemoimmunotherapy regimen of fludarabine, cyclophosphamide, and rituximab as initial therapy for chronic lymphocytic leukemia. J Clin Oncol 2005;23: 4079-88. 4. Kay NE, Geyer SM, Call TG, Shanafelt TD, Zent CS, Jelinek DF, et al. Combination chemoimmunotherapy with pentostatin, cyclophosphamide, and rituximab shows significant clinical activity with low accompanying toxicity in previously untreated B chronic lymphocytic leukemia. Blood 2007;109: 405-11. 5. Juliusson G, Elmhorn-Rosenborg A, Liliemark J. Response to 2-chlorodeoxyadenosine in patients with B-cell chronic lymphocytic leukemia resistant to fludarabine. N Engl J Med 1992; 327:1056-61. 6. O'Brien S, Kantarjian H, Estey E, Koller C, Robertson B, Beran M, et al. Lack of effect of 2-chlorodeoxyadenosine therapy in patients with chronic lymphocytic leukemia refractory to fludarabine therapy. N Engl J Med 1994;330:319-22. 7. Kantarjian HM, Gandhi V, Kozuch P, Faderl S, Giles F, Cortes J, et al. Phase I clinical and pharmacology study of clofarabine in patients with solid and hematologic cancers. J Clin Oncol 2003;21:1167-73. 8. Keating MJ, Flinn I, Jain V, Binet JL, Hillmen P, Byrd J, et al. Therapeutic role of alemtuzumab (Campath-1H) in patients 19. 20. 21. 22. 23. 24. 25. 26. who have failed fludarabine: results of a large international study. Blood 2002;99:3554-61. Bichi R, Shinton SA, Martin ES, Koval A, Calin GA, Cesari R, et al. Human chronic lymphocytic leukemia modeled in mouse by targeted TCL1 expression. Proc Natl Acad Sci USA 2002;99:6955-60. Johnson AJ, Lucas DM, Muthusamy N, Smith LL, Edwards RB, De Lay MD, et al. Characterization of the TCL-1 transgenic mouse as a preclinical drug development tool for human chronic lymphocytic leukemia. Blood 2006; 108:1334-8. O'Brien S, Moore JO, Boyd TE, Larratt LM, Skotnicki A, Koziner B, et al. Randomized phase III trial of fludarabine plus cyclophosphamide with or without oblimersen sodium (Bcl-2 antisense) in patients with relapsed or refractory chronic lymphocytic leukemia. J Clin Oncol 2007. Faderl S, Rai K, Gribben J, Byrd JC, Flinn IW, O'Brien S, et al. Phase II study of single-agent bortezomib for the treatment of patients with fludarabine-refractory B-cell chronic lymphocytic leukemia. Cancer 2006;107:916-24. Chanan-Khan A, Miller KC, Musial L, Lawrence D, Padmanabhan S, Takeshita K, et al. Clinical efficacy of lenalidomide in patients with relapsed or refractory chronic lymphocytic leukemia: results of a phase II study. J Clin Oncol 2006;24: 5343-9. Flinn IW, Byrd JC, Bartlett N, Kipps T, Gribben J, Thomas D, et al. Flavopiridol administered as a 24-hour continuous infusion in chronic lymphocytic leukemia lacks clinical activity. Leuk Res 2005;29:1253-7. Moreton P, Kennedy B, Lucas G, Leach M, Rassam SM, Haynes A, et al. Eradication of minimal residual disease in Bcell chronic lymphocytic leukemia after alemtuzumab therapy is associated with prolonged survival. J Clin Oncol 2005; 23: 2971-9. Montillo M, Tedeschi A, Miqueleiz S, Veronese S, Cairoli R, Intropido L, et al. Alemtuzumab as consolidation after a response to fludarabine is effective in purging residual disease in patients with chronic lymphocytic leukemia. J Clin Oncol 2006;24:2337-42. Wendtner CM, Ritgen M, Schweighofer CD, Fingerle-Rowson G, Campe H, Jager G, et al. Consolidation with alemtuzumab in patients with chronic lymphocytic leukemia (CLL) in first remission--experience on safety and efficacy within a randomized multicenter phase III trial of the German CLL Study Group (GCLLSG). Leukemia 2004;18:1093-101. Elter T, Borchmann P, Schulz H, Reiser M, Trelle S, Schnell R, et al. Fludarabine in combination with alemtuzumab is effective and feasible in patients with relapsed or refractory B-cell chronic lymphocytic leukemia: results of a phase II trial. J Clin Oncol 2005;23:7024-31. Faderl S, Thomas DA, O'Brien S, Garcia-Manero G, Kantarjian HM, Giles FJ, et al. Experience with alemtuzumab plus rituximab in patients with relapsed and refractory lymphoid malignancies. Blood 2003;101:3413-5. O'Brien SM, Kantarjian H, Thomas DA, Giles FJ, Freireich EJ, Cortes J, et al. Rituximab dose-escalation trial in chronic lymphocytic leukemia. J Clin Oncol 2001;19:2165-70. Byrd JC, Murphy T, Howard RS, Lucas MS, Goodrich A, Park K, et al. Rituximab using a thrice weekly dosing schedule in Bcell chronic lymphocytic leukemia and small lymphocytic lymphoma demonstrates clinical activity and acceptable toxicity. J Clin Oncol 2001;19:2153-64. Byrd JC, Smith L, Hackbarth ML, Flinn IW, Young D, Proffitt JH, et al. Interphase cytogenetic abnormalities in chronic lymphocytic leukemia may predict response to rituximab. Cancer Res 2003;63:36-8. Byrd JC, Rai K, Peterson BL, Appelbaum FR, Morrison VA, Kolitz JE, et al. Addition of rituximab to fludarabine may prolong progression-free survival and overall survival in patients with previously untreated chronic lymphocytic leukemia: an updated retrospective comparative analysis of CALGB 9712 and CALGB 9011. Blood 2005;105:49-53. Thornton PD, Matutes E, Bosanquet AG, Lakhani AK, Grech H, Ropner JE, et al. High dose methylprednisolone can induce remissions in CLL patients with p53 abnormalities. Ann Hematol 2003;82:759-65. Castro JE, Prada CE, Loria O, Kamal A, Chen L, Burrows FJ, et al. ZAP-70 is a novel conditional heat shock protein 90 (Hsp90) client: inhibition of Hsp90 leads to ZAP-70 degradation, apoptosis, and impaired signaling in chronic lymphocytic leukemia. Blood 2005;106:2506-12. Coll-Mulet L, Iglesias-Serret D, Santidrian AF, Cosialls AM, de Frias M, Castano E, et al. MDM2 antagonists activate p53 and | 132 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 27. 28. 29. 30. synergize with genotoxic drugs in B-cell chronic lymphocytic leukemia cells. Blood 2006;107:4109-14. Byrd JC, Shinn C, Willis CR, Flinn IW, Lehman T, Sausville E, et al. UCN-01 induces cytotoxicity toward human CLL cells through a p53-independent mechanism. Exp Hematol 2001;29:703-8. Ganeshaguru K, Wickremasinghe RG, Jones DT, Gordon M, Hart SM, Virchis AE, et al. Actions of the selective protein kinase C inhibitor PKC412 on B-chronic lymphocytic leukemia cells in vitro. Haematologica 2002;87:167-76. Alvi AJ, Austen B, Weston VJ, Fegan C, MacCallum D, Gianella-Borradori A, et al. A novel CDK inhibitor, CYC202 (R-roscovitine), overcomes the defect in p53-dependent apoptosis in B-CLL by down-regulation of genes involved in transcription regulation and survival. Blood 2005;105:4484-91. Byrd JC, Marcucci G, Parthun MR, Xiao JJ, Klisovic RB, Moran M, et al. A phase 1 and pharmacodynamic study of depsipeptide (FK228) in chronic lymphocytic leukemia and acute myeloid leukemia. Blood 2005;105:959-67. 31. Lucas DM, Davis ME, Parthun MR, Mone AP, Kitada S, Cunningham KD, et al. The histone deacetylase inhibitor MS275 induces caspase-dependent apoptosis in B-cell chronic lymphocytic leukemia cells. Leukemia 2004;18:1207-14. 32. Shanafelt TD, Lee YK, Call TG, Nowakowski GS, Dingli D, Zent CS, et al. Clinical effects of oral green tea extracts in four patients with low grade B-cell malignancies. Leuk Res 2006;30:707-12. 33. Robak P, Linke A, Cebula B, Robak T, Smolewski P. Cytotoxic effect of R-etodolac (SDX-101) in combination with purine analogs or monoclonal antibodies on ex vivo B-cell chronic lymphocytic leukemia cells. Leuk Lymphoma 2006;47:262534. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 133 | Sickle Cell Disease Hemolysis-associated pulmonary hypertension in sickle cell disease and thalassemia G.J. Kato1,2 M.T. Gladwin1,2 1 Vascular Medicine Branch, National Heart Lung and Blood Institute; 2 Critical Care Medicine Department, Clinical Center National Institutes of Health, Bethesda, Maryland, USA Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:134-139 | 134 | edical advances in the management of patients with sickle cell disease, thalassemia, and other hemolytic anemias have led to significant increases in life expectancy. Improved public health, neonatal screening, parental and patient education, advances in red cell transfusion medicine, iron chelation therapy, penicillin prophylaxis for children, pneumococcal immunization, and hydroxyurea therapy have all probably contributed to this effect on longevity. Importantly, as a generation of patients with sickle cell disease and thalassemia ages, new chronic complications of these hemoglobinopathies emerge. In this context, pulmonary hypertension is emerging as one of the leading causes of morbidity and mortality in adult sickle cell and thalassemia patients, and in patients with other hemolytic anemias. A common feature of both sickle cell disease and thalassemia is intravascular hemolysis and chronic anemia. Recent data suggests that chronic intravascular hemolysis is associated with a state of endothelial dysfunction. This is characterized by reduced nitric oxide (NO) bioavailability, pro-oxidant and proinflammatory stress and coagulopathy, leading to vasomotor instability and ultimately producing a proliferative vasculopathy, with the development of pulmonary hypertension in adulthood. This article will briefly review the role of NO in homeostatic endothelial and vasomotor function and the specific mechanisms of endothelial dysfunction in sickle cell disease. The mechanisms held responsible for the development of pulmonary hypertension in hemolytic diseases and the role of pulmonary hypertension as a risk factor for death in patients with sickle cell anemia will then be discussed. Finally, a case will be made that hemolytic anemia produces a clinical subphenotype in patients with sickle cell disease that is shared by other hemolytic disorders, a phenotype characterized by pul- M monary hypertension, priapism, cutaneous leg ulceration, sudden death, and possibly stroke. Hemolysis, a forgotten complication of sickle cell disease Sickle cell disease is basically a form of hemolytic anemia. The average patient with SCD has a hemoglobin level that is approximately one-half that of normal. The red cell survival is as low as 10-20 days, requiring massively increased red cell production to maintain even this very low hemoglobin level, indicated by a reticulocyte count elevation often five to twenty times normal. The red cell mass hemolyzed in a single day has been estimated to release 30 gm of hemoglobin. Although approximately two-thirds of the hemolysis takes place extravascularly in the reticuloendothelial system, the remaining one-third of the hemolysis occurs intravascularly, decompartmentalizing up to 10 gm of hemoglobin and other red cell contents into blood plasma daily.1 Almost 40 years ago, Naumann and Neely and their colleagues documented the high levels of hemoglobin and lactate dehydrogenase (LDH) in the plasma of patients with SCD.2,3 They also demonstrated crisis-associated hyperhemolysis, with sharply higher levels of plasma hemoglobin and LDH during vaso-occlusive pain crisis. Using more modern methods, these pioneering findings have recently been confirmed by our group and by Ballas and colleagues.4,5 These levels far exceed the hemoglobin-scavenging capacity of the haptoglobin-hemopexin system, resulting in prolonged exposure of the blood vessel wall and blood plasma to high levels of hemoglobin. NO and vascular function Nitric oxide (NO) is a soluble diatomic gas molecule, produced by the endothelial cells that line the blood vessel. It serves as a master regulator of vascular function and enhances blood flow.6 NO diffuses from Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 the endothelial cell, binding to its primary receptor in vascular smooth muscle cells, guanylyl cyclase, activating the conversion of GTP to cGMP. This cyclic nucleotide induces a signal transduction cascade that effects smooth muscle relaxation and vasodilation. NO also represses a whole program of pathways that contribute to vascular obstruction. NO represses activation of platelets and endothelial cells, release of coagulation factors, and expression of endothelial adhesion molecules. This response seems to have evolved so that loss of NO signaling results in hemostasis, including vasoconstriction, endothelial adhesiveness and thrombosis. Intravascular hemolysis and impaired NO bioavailability There are multiple lines of evidence indicating impaired nitric oxide bioavailability in patients and mice with SCD, linked to intravascular hemolysis. This decompartmentalization of red cell contents into blood plasma releases hemoglobin, which inactivates NO in a diffusion-limited stoichiometric reaction, generating plasma methemoglobin and inert nitrate.5 The large amount of hemoglobin released into blood plasma in SCD saturates and overwhelms the hemoglobin scavenging system, resulting in prolonged exposure of endothelial cells to levels of plasma hemoglobin in the 10-20 µM range, at times reaching levels of 50-100 µM. This degree of hemoglobinemia results in readily identifiable blunted vasodilatory responses to exogenous nitric oxide donors in several human and animal blood flow physiology studies, constituting a form of nitric oxide resistance.6-12 These data imply that in patients with SCD, a portion of NO released from endothelial cells is intercepted by plasma hemoglobin, diminishing its bioavailability to effector cells. Intravascular hemolysis also releases red cell arginase into blood plasma, which worsens the state of impaired NO bioavailability. This ectopic arginase activity depletes blood plasma of L-arginine, limiting the expected compensatory increase in NO production due to accelerated NO turnover. Plasma arginase or its proxy (decreased arginine: ornithine ratio) is associated with pulmonary hypertension and risk of early mortality.13 Parallel findings are seen in thalassemia.14 Increased plasma levels of methylated arginine species are also detectable in patients with SCD, which may potentially further impair L-arginine transport or NO synthase activity in endothelial cells.15 Reactive oxygen species can also impair NO bioavailability in SCD.16-18 These oxygen radicals can react stoichiometrically with NO, contributing to NO depletion and giving rise to highly oxidative peroxynitrite.19 Besides inhibiting NO production, depletion of L-arginine can uncouple NO synthase activity, Table 1. Contributory factors to hemolysis-associated vasculopathy. Scavenging of nitric oxide by cell-free plasma hemoglobin Diversion of plasma L-arginine by cell-free plasma arginase from nitric oxide synthase Generation of oxygen radicals: Xanthine oxidase NADPH oxidase Uncoupled nitric oxide synthase activity causing it to generate reactive oxygen species.20 Xanthine oxidase and NADPH oxidase, present in large amounts in sickle cell blood vessels, also produce superoxides and hydrogen peroxides.17,21 Oxygen radical production in SCD is associated with endothelial dysfunction (Table 1). Sickle vasculopathy: pulmonary hypertension Pulmonary hypertension was the first sickle cell complication to be linked to NO scavenging due to chronic intravascular hemolysis. Once considered a rare occurrence in SCD, more recent reports indicate the frequency of pulmonary hypertension, and its association with early death.22,23 Prospective echocardiography screening studies indicate that approximately one-third of adults with SCD have a tricuspid regurgitant jet velocity (TRV) of 2.5 m/sec or higher.24-26 Furthermore, such patients have a 9-10-fold risk for early mortality compared to those with a normal TRV.24,27 Further characterization of a subset of these patients with right heart catheterization studies indicate that the vast majority of patients with a high TRV have pulmonary arterial hypertension (PAH), a state of chronic pulmonary vasoconstriction leading to chronic proliferative vascular changes.24 Independent correlates of high TRV include older age, systolic hypertension, and markers of high hemolytic rate, renal insufficiency, iron overload and a subtle cholestatic hepatopathy. Frequency of vaso-occlusive pain or acute chest syndrome episodes do not appear to contribute. Interestingly, SCD males with a high TRV are more likely to have a history of priapism.24 Concurrent with hyperhemolysis during vaso-occlusive crisis, the TRV rises acutely, then later falls back to baseline levels.28 There has been some controversery as to whether pulmonary hypertension in SCD might be due to left ventricular diastolic dysfunction (LVDD). In a recent study by our group, tissue Doppler measurements and other detailed echocardiographic analysis indicate that LVDD and PAH are independent and additive risk factors for death.29 In this cohort, roughly three-quarters of SCD adults with TRV ≥2.5 m/sec have isolated pulmonary arterial hypertension. The remaining quar- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 135 | 12th Congress of the European Hematology Association ter have evidence of combined PAH and LVDD, with a far worse prognosis than either PAH or LVDD alone (Figure 1). Finally, only 7% of the entire cohort had isolated LVDD without PAH. The primary correlates of LVDD were systemic hypertension and renal insufficiency. Thus LVDD and PAH are independent and overlapping risk factors for early mortality in SCD, but isolated PAH appears to be three times as common. Pulmonary hypertension is now also known to occur frequently in patients with thalassemia.30-36 Its prevalence may exceed 65% in untransfused thalassemia intermedia patients, who have particularly severe chronic intravascular hemolysis. Originally, such cases were believed to be caused by recurrent pulmonary emboli, but the mechanism of hemolysisassociated impairment of NO bioavailability, may better define the clinical circumstances,14 especially since recurrent pulmonary thrombosis in situ is a recognized common complication of all forms of pulmonary hypertension.37 Many reports indicate that pulmonary hypertension is more frequently recognized in thalassemia patients who have undergone splenectomy.38-40 Although it is possible that surgical splenectomy serves only to identify a subset of patients with more severe and high risk thalassemia, there is circumstantial evidence that post-splenectomy thalassemia patients have higher levels of cellfree plasma hemoglobin.41 Even though splenectomy may reduce the overall hemolytic rate, it might shunt a portion of hemolysis from an extravascular to intravascular pattern, resulting in the observed high level of plasma hemoglobin, and high levels of plasma arginase which are probably associated. Since NO is well known to suppress hemostasis at many levels, including platelet activation and adhesion, and release of tissue factor and other procoagulant proteins,42 decreased bioavailability of NO may account in part for the thromboembolic events that are gaining increased recognition in thalassemia patients.43-49 Sickle vasculopathy: cutaneous leg ulceration Leg ulceration occurs in about 20% of patients with SCD, often a troublesome and recurrent problem. These ulcers develop most frequently in those patients with clinical markers of more severe chronic hemolysis: lower hemoglobin, higher serum bilirubin and LDH.50 SCD patients with concurrent α-thalassemia, which serves to reduce hemolysis, have a lower prevalence of leg ulcers.51,52 SCD males with leg ulcers are more likely to have a history of priapism. Polymorphisms are more common in SCD patients with leg ulcers in genes implicated in pathways affecting angiogenesis and vascular function: Klotho, TEK, TGF-β and BMP.50 All of these data point to a pattern of hemolysis-associated vascular dysfunction PAH Only 29% RR 3.4 Normal 51% LVDD Only 7% RR 4.8 Both 11% RR 12.0 Figure 1. Relative contribution of diastolic dysfunction in sickle cell pulmonary hypertension. In a subset of 138 sickle cell patients studied in detail with echocardiography and tissue Doppler measurements, 29% had isolated pulmonary arterial hypertension (PAH), as indicated by TRV ≥2.5 m/sec; 7% met criteria for isolated left ventricular diastolic dysfunction (LVDD); and 11% had evidence of simultaneous PAH and LVDD. Either PAH or LVDD alone were associated with an increased relative risk (RR) of early mortality, but simultaneous PAH and LVDD was associated with a particularly poor prognosis. Diagram adapted from reference 29. in the development of leg ulceration in patients with SCD. So sickling does not appear to be necessary for leg ulceration. Leg ulcers are also described in thalassemia, particularly thalassemia intermedia, and hereditary spherocytosis.53–60 They have been reported in other hemolytic anemias, including pyruvate kinase deficiency.61,62 Sickle vasculopathy: priapism A very similar picture has emerged for the relationship of priapism and hemolysis associated vascular dysfunction. Males with SCD and a history of priapism are more likely to have clinical markers of accelerated hemolysis: lower hemoglobin, higher reticulocyte counts, and higher serum levels of bilirubin, and LDH.63 Like leg ulcers, priapism has been linked to polymorphisms of the Klotho gene.64 A link to hemolysis, is further supported by reports of priapism in several other hemolytic disorders besides SCD, particularly thalassemia.65-71 Since penile erection requires NO bioactivity, it would be expected that the hemolysis-related impairment in NO bioavailability would tend to inhibit, not promote, priapism. However, consistent with the association of priapism and NO consumption in SCD, the eNOS | 136 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 2. Subphenotypes of sickle cell disease. Hemolysis-associated vasculopathy Pulmonary arterial hypertension Cutaneous leg ulceration Priapism Ischemic stroke? Viscosity-vaso-occlusion syndrome Vaso-occlusive pain crisis Acute chest syndrome Osteonecrosis deficient mouse also develops priapism.72 The proposed cause of this paradoxical association of priapism with impaired NO bioavailability is loss of NO-stimulated phosphodiesterase-5 (PDE5) expression. Intermittent treatment with PDE5 inhibitors is thought to induce a compensatory increase in PDE5 protein expression, which ultimately serves to reduce priapic activity in pilot studies in patients with SCD.73,74 Is stroke part of sickle vasculopathy? Cerebrovascular disease with ischemic stroke is another example of large-vessel arteriopathy, histopathologically very similar to pulmonary hypertension.75,76 Like pulmonary hypertension, ischemic stroke in SCD has been epidemiologically linked to a low hemoglobin level and higher systemic systolic blood pressure.77 Although the contribution of a hemolysis-associated low NO state to cerebrovascular disease in SCD is an attractive hypothesis, it has not been specifically investigated. However, our group has published a case series of six patients with SCD and PAH who developed cerebrovascular disease or stroke.78 The characteristics of these patients support the hypothesis that cerebrovascular disease may be part of the spectrum of sickle vasculopathy, but further research in this area is needed. Sickle vasculopathy and platelet activation For many years, high levels of platelet activation have been recognized in patients with sickle cell disease.79-81 The level of platelet activation appears to be even higher during vaso-occlusive crisis.80 Our group has found that platelet activation correlates significantly with the TRV in patients with SCD, and to some extent also with markers of hemolytic severity.82 This suggests that platelet activation may join vasoconstriction as a downstream consequence of hemolysis-associated impaired NO bioavailability. This interpretation is consistent with the known strong anti-platelet effects of NO.83 Once again, some parallel findings have been reported in thalassemia.84 Vasculopathy versus viscosity-vaso-occlusion The concepts presented above describe a subset of sickle cell complications that were previously ascribed to sickling and vaso-occlusion. Although sickling may play a role in these disorders, there are now stronger mechanistic and epidemiologic data to implicate hemolysis-associated impairment of nitric oxide bioavailability. The steady state serum level of lactate dehydrogenase is in large part an indicator of intravascular hemolysis in SCD, and is associated with impaired NO bioavailability, PAH, leg ulcers, priapism and early mortality.85 These complications are associated with particularly severe hemolytic anemia. In contrast, vaso-occlusive crisis, acute chest syndrome, and osteonecrosis of the femoral head have been associated with less severe hemolysis and higher hemoglobin, presumably leading to high blood viscosity and poor microvascular blood flow and tissue infarction (Table 2). We have described in detail the body of data supporting this model.86 In support of this concept, as described above, these features of the hemolytic vasculopathy syndrome have all been reported in thalassemia and other hemolytic disorders, demonstrating that sickling is not required for these complications to occur. However, it is likely that sickling and cell adhesion mechanisms increase the vasculopathy defect. Pulmonary hypertension: diagnosis and treatment The most useful screening modality for pulmonary hypertension has been echocardiography, with careful measurement of TRV in two or three views. Our screening data and confirmation by others indicate that 2.5 m/sec is a threshold for abnormal values.24 There may be a role for measurement of serum Nterminal pro-brain-type natriuretic peptide (NTproBNP) to identify the highest risk patients for echocardiography, but this requires further study.87 A small minority of patients may have mitral valvular insufficiency rather than pulmonary hypertension, but this should be readily detected on echo. Patients with TRV 2.5-2.9 m/sec should be followed clinically for any other cardiopulmonary concerns, with follow up studies every 6-24 months. In patients with repeated TRV ≥ 3 m/sec, consideration should be given to right heart catheterization studies by a pulmonologist or cardiologist experienced with pulmonary hypertension. More detailed studies may be clinically indicated.88 Right heart catheterization data will confirm whether pulmonary hypertension is present, its severity and whether this is due to PAH, or to LVDD.29 Encouraging pilot data indicate a potential role for sildenafil, and there are other approved treatments for PAH for which specific studies are underway in SCD and thalassemia.89,90 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 137 | 12th Congress of the European Hematology Association Conclusions Pulmonary hypertension is a complication of sickle cell disease and thalassemia that is frequently underdiagnosed. Progressive dyspnea on exertion may be misattributed to chronic anemia. Even mild pulmonary hypertension is poorly tolerated in SCD, is associated with early mortality. Pulmonary hypertension, leg ulceration and priapism are epidemiologically associated, reflecting a new subphenotype of SCD with a common pathophysiological mechanism. Although the etiology is undoubtedly multifactorial, one large component, marked by elevated steady state serum LDH levels, involves impaired NO bioavailability, mainly due to scavenging of NO by cell-free plasma hemoglobin. Important new directions in SCD and thalassemia will include improved screening for PAH and larger scale clinical trials of therapeutic agents for PAH and associated vasculopathy. Acknowledgements The authors are supported by intramural funds from the National Institutes of Health. M.T.G. also holds a cooperative research and development agreement with INO Therapeutics. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. References 1. Crosby WH. The metabolism of hemoglobin and bile pigment in hemolytic disease. Am J Med 1955;18:112-22. 2. Naumann HN, Diggs LW, Barreras L, Williams BJ. Plasma hemoglobin and hemoglobin fractions in sickle cell crisis. Am J Clin Pathol 1971;56:137-47. 3. Neely CL, Wajima T, Kraus AP, Diggs LW, Barreras L. Lactic acid dehydrogenase activity and plasma hemoglobin elevations in sickle cell disease. Am J Clin Pathol 1969;52:167-9. 4. Ballas SK, Marcolina MJ. Hyperhemolysis during the evolution of uncomplicated acute painful episodes in patients with sickle cell anemia. Transfusion (Paris). 2006;46:105-10. 5. Reiter CD, Wang X, Tanus-Santos JE et al. Cell-free hemoglobin limits nitric oxide bioavailability in sickle-cell disease. Nat Med 2002;8:1383-9. 6. Walford G, Loscalzo J. Nitric oxide in vascular biology. J Thromb Haemost 2003;1:2112-8. 7. Gladwin MT, Schechter AN, Ognibene FP et al. Divergent nitric oxide bioavailability in men and women with sickle cell disease. Circulation 2003;107:271-8. 8. Eberhardt RT, McMahon L, Duffy SJ et al. Sickle cell anemia is associated with reduced nitric oxide bioactivity in peripheral conduit and resistance vessels. Am J Hematol 2003;74:104-11. 9. Belhassen L, Pelle G, Sediame S et al. Endothelial dysfunction in patients with sickle cell disease is related to selective impairment of shear stress-mediated vasodilation. Blood 2001;97: 1584-9. 10. Kaul DK, Liu XD, Chang HY, Nagel RL, Fabry ME. Effect of fetal hemoglobin on microvascular regulation in sickle transgenic-knockout mice. J Clin Invest 2004;114:1136-45. 11. Nath KA, Shah V, Haggard JJ et al. Mechanisms of vascular instability in a transgenic mouse model of sickle cell disease. Am.J.Physiol.Regul.Integr.Comp Physiol 2000;279:R1949-55. 12. Kaul DK, Liu XD, Fabry ME, Nagel RL. Impaired nitric oxidemediated vasodilation in transgenic sickle mouse. Am J Physiol Heart Circ Physiol 2000;278:H1799-806. 13. Morris CR, Kato GJ, Poljakovic M et al. Dysregulated Arginine Metabolism, Hemolysis-Associated Pulmonary Hypertension and Mortality in Sickle Cell Disease. JAMA 2005;294:81-90. 14. Morris CR, Kuypers FA, Kato GJ et al. Hemolysis-associated pulmonary hypertension in thalassemia. Ann NY Acad Sci 2005;1054:481-5:481-5. 15. Schnog JB, Teerlink T, van der Dijs FP, Duits AJ, Muskiet FA. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. Plasma levels of asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, are elevated in sickle cell disease. Ann Hematol 2004;84:282-6. Aslan M, Thornley-Brown D, Freeman BA. Reactive species in sickle cell disease. Ann NY Acad Sci 2000;899:375-91. Aslan M, Ryan TM, Adler B et al. Oxygen radical inhibition of nitric oxide-dependent vascular function in sickle cell disease. Proc Natl AcadSci USA 2001;98:15215-20. Aslan M, Freeman BA. Oxidant-mediated impairment of nitric oxide signaling in sickle cell disease–mechanisms and consequences. Cell Mol Biol (Noisy.-le-grand) 2004;50:95-105. Aslan M, Ryan TM, Townes TM et al. Nitric oxide-dependent generation of reactive species in sickle cell disease. Actin tyrosine induces defective cytoskeletal polymerization. J Bio Chem 2003;278:4194-204. Xia Y, Dawson VL, Dawson TM, Snyder SH, Zweier JL. Nitric oxide synthase generates superoxide and nitric oxide in arginine-depleted cells leading to peroxynitrite-mediated cellular injury. Proc Natl Acad Sci USA 1996;93:6770-4. Wood KC, Hebbel RP, Granger DN. Endothelial cell NADPH oxidase mediates the cerebral microvascular dysfunction in sickle cell transgenic mice. FASEB J 2005;19:989-91. Sutton LL, Castro O, Cross DJ, Spencer JE, Lewis JF. Pulmonary hypertension in sickle cell disease. Am J Cardiol 1994;74:626-8. Castro O, Hoque M, Brown BD. Pulmonary hypertension in sickle cell disease: cardiac catheterization results and survival. Blood 2003;101:1257-61. Gladwin MT, Sachdev V, Jison ML et al. Pulmonary hypertension as a risk factor for death in patients with sickle cell disease. N Engl J Med 2004;350:886-95. Ataga KI, Sood N, De GG et al. Pulmonary hypertension in sickle cell disease. Am J Med 2004;117:665-9. De Castro LM, Jonassaint JC, Graham FL, Ashley-Koch A, Telen MJ. Pulmonary Hypertension in SS, SC and SbThalassemia: Prevalence, Associated Clinical Syndromes, and Mortality. Blood 2004;104:462a. Ataga KI, Moore CG, Jones S et al. Pulmonary hypertension in patients with sickle cell disease: a longitudinal study. Br J Haematol 2006;134:109-15. Machado RF, Kyle MA, Martyr S et al. Severity of pulmonary hypertension during vaso-occlusive pain crisis and exercise in patients with sickle cell disease. Br J Haematol 2007;136:319-25. Sachdev V, Machado RF, Shizukuda Y et al. Diastolic Dysfunction is an independent risk factor for death in patients with sickle cell disease. J Am Coll Cardiol 2007;49:472-9. Aessopos A, Farmakis D, Deftereos S et al. Thalassemia heart disease: a comparative evaluation of thalassemia major and thalassemia intermedia. Chest 2005;127:1523-30. Aessopos A, Farmakis D. Pulmonary hypertension in beta-thalassemia. Ann NY Acad Sci 2005;1054:342-9. Aessopos A, Farmakis D, Karagiorga M et al. Cardiac involvement in thalassemia intermedia: a multicenter study. Blood 2001;97:3411-6. Du ZD, Roguin N, Milgram E, Saab K, Koren A. Pulmonary hypertension in patients with thalassemia major. Am Heart J 1997;134:532-7. Aessopos A, Stamatelos G, Skoumas V et al. Pulmonary hypertension and right heart failure in patients with beta-thalassemia intermedia. Chest 1995;107:50-3. Koren A, Garty I, Antonelli D, Katzuni E. Right ventricular cardiac dysfunction in beta-thalassemia major. Am J Dis Child 1987;141:93-6. Chotivittayatarakorn P, Seksarn P, Pathmanand C, Thisyakorn C, Sueblinvong V. Cardiac dysfunction in beta-thalassemic children. J Med Assoc Thai 1993;76:591-6. Raiesdana A, Loscalzo J. Pulmonary arterial hypertension. Ann Med 2006;38:95-110. Atichartakarn V, Likittanasombat K, Chuncharunee S et al. Pulmonary arterial hypertension in previously splenectomized patients with beta-thalassemic disorders. Int J Hematol 2003;78:139-45. Aessopos A, Farmakis D, Deftereos S et al. Cardiovascular effects of splenomegaly and splenectomy in beta-thalassemia. Ann Hematol 2005;84:353-7. Wu KH, Chang JS, Su BH, Peng CT. Tricuspid regurgitation in patients with beta-thalassemia major. Ann Hematol 2004; 83:779-83. Westerman MP, Pizzey A, Hirschmann JV et al. Plasma free HB is related to red cell derived vesicle numbers in sickle cell anemia and thalassemia intermedia: implications for nitric oxide (NO) scavenging and pulmonary hypertension [abstract]. Blood 2004;104:465a. | 138 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 42. Loscalzo J. Nitric oxide insufficiency, platelet activation, and arterial thrombosis. Circ Res 2001;88:756-62. 43. Chuansumrit A, Hathirat P, Isarangkura P, Pintadit P, Mahaphan W. Thrombotic risk of children with thalassemia. J Med Assoc Thai 1993;76 Suppl 2:80-4. 44. Cohen AR, Galanello R, Pennell DJ, Cunningham MJ, Vichinsky E. Thalassemia. Hematology (Am Soc Hematol Educ Program) 200414-34. 45. Visudhiphan S, Ketsa-Ard K, Tumliang S, Piankijagum A. Significance of blood coagulation and platelet profiles in relation to pulmonary thrombosis in beta-thalassemia/Hb E. Southeast Asian J Trop.Med.Public Health 1994;25:449-56. 46. Taher A, Abou-Mourad Y, Abchee A, Zalouaa P, Shamseddine A. Pulmonary thromboembolism in beta-thalassemia intermedia: are we aware of this complication? Hemoglobin 2002;26:107-12. 47. Moratelli S, De Sanctis V, Gemmati D et al. Thrombotic risk in thalassemic patients. J Pediatr Endocrinol Metab 1998;11 Suppl 3:915-21. 48. Michaeli J, Mittelman M, Grisaru D, Rachmilewitz EA. Thromboembolic complications in beta thalassemia major. Acta Haematol 1992;87:71-4. 49. Sonakul D, Suwanagool P, Sirivaidyapong P, Fucharoen S. Distribution of pulmonary thromboembolic lesions in thalassemic patients. Birth Defects Orig Artic Ser 1987;23:375-84. 50. Nolan VG, Adewoye AH, Baldwin CT et al. Associations with haemolysis and SNPs in KlOTHO, TEK and genes of the TGFβ/BMP pathway. Br J Haematol. In press. 51. Koshy M, Entsuah R, Koranda A et al. Leg ulcers in patients with sickle cell disease. Blood 1989;74:1403-8. 52. Nolan VG, Adewoye A, Baldwin C et al. Sickle cell leg ulcers: associations with haemolysis and SNPs in Klotho, TEK and genes of the TGF-beta/BMP pathway. Br J Haematol 2006; 133:570-8. 53. Stevens DM, Shupack JL, Javid J, Silber R. Ulcers of the leg in thalassemia. Arch Dermatol 1977;113:1558-60. 54. Pope FM, Hodgson GA. Leg ulceration and thalassaemia. Br J Dermatol 1968;80:840. 55. Taher A, Isma'eel H, Cappellini MD. Thalassemia intermedia: revisited. Blood Cells Mol Dis 2006;37:12-20. 56. Levy LA. Foot and ankle ulcers associated with hematologic disorders. Clin Podiatry 1985;2:631-7. 57. Giraldi S, Abbage KT, Marinoni LP et al. Leg ulcer in hereditary spherocytosis. Pediatr Dermatol 2003;20:427-8. 58. Lawrence P, Aronson I, Saxe N, Jacobs P. Leg ulcers in hereditary spherocytosis. Clin Exp Dermatol 1991;16:28-30. 59. Vanscheidt W, Leder O, Vanscheidt E et al. Leg ulcers in a patient with spherocytosis: a clinicopathological report. Dermatologica 1990;181:56-9. 60. Marks J, Shuster S. Anaemia and skin disease. Postgrad Med J 1970;46:659-63. 61. Muller-Soyano A, Tovar dR, Duke PR et al. Pyruvate kinase deficiency and leg ulcers. Blood 1976;47:807-13. 62. Tanaka KR, Paglia DE. Pyruvate kinase deficiency. Semin Hematol 1971;8:367-96. 63. Nolan VG, Wyszynski DF, Farrer LA, Steinberg MH. Hemolysis-associated priapism in sickle cell disease. Blood 2005;106:3264-7. 64. Nolan VG, Baldwin C, Ma Q et al. Association of single nucleotide polymorphisms in klotho with priapism in sickle cell anaemia. Br J Haematol 2005;128:266-72. 65. Thuret I, Bardakdjian J, Badens C et al. Priapism following splenectomy in an unstable hemoglobin: hemoglobin Olmsted beta 141 (H19) Leu-->Arg. Am J Hematol 1996;51:133-6. 66. Edney MT, Schned AR, Cendron M, Chaffee S, Ellsworth PI. Priapism in a 15-year-old boy with congenital dyserythropoietic anemia type II (hereditary erythroblastic multinuclearity with positive acidified serum lysis test). J Urol 2002;167:30910. 67. Dore F, Bonfigli S, Pardini S, Pirozzi F, Longinotti M. Priapism in thalassemia intermedia. Haematologica 1991;76:523. 68. Montalban J, Lozano P, Lu L, Gonzalez A. [Paroxysmal noctur- 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. nal hemoglobinuria and priapism]. Med Clin (Barc.) 1986;87 :394. Goulding FJ. Priapism caused by glucose phosphate isomerase deficiency. J Urol 1976;116:819-20. Macchia P, Massei F, Nardi M et al. Thalassemia intermedia and recurrent priapism following splenectomy. Haematologica 1990;75:486-7. Jackson N, Franklin IM, Hughes MA. Recurrent priapism following splenectomy for thalassaemia intermedia. Br J Surg 1986;73:678. Champion HC, Bivalacqua TJ, Takimoto E, Kass DA, Burnett AL. Phosphodiesterase-5A dysregulation in penile erectile tissue is a mechanism of priapism. Proc Natl Acad Sci USA 2005;102:1661-6. Burnett AL, Bivalacqua TJ, Champion HC, Musicki B. Longterm oral phosphodiesterase 5 inhibitor therapy alleviates recurrent priapism. Urology 2006;67:1043-8. Bialecki ES, Bridges KR. Sildenafil relieves priapism in patients with sickle cell disease. Am J Med 2002;113:252. Haque AK, Gokhale S, Rampy BA et al. Pulmonary hypertension in sickle cell hemoglobinopathy: a clinicopathologic study of 20 cases. Hum Pathol 2002;33:1037-43. Rothman SM, Fulling KH, Nelson JS. Sickle cell anemia and central nervous system infarction: a neuropathological study. Ann Neurol 1986;20:684-90. Ohene-Frempong K, Weiner SJ, Sleeper LA et al. Cerebrovascular accidents in sickle cell disease: rates and risk factors. Blood 1998;91:288-94. Kato GJ, Hsieh M, Machado RF et al. Cerebrovascular disease associated with sickle cell pulmonary hypertension. Am J Hematol 2006;81:503-10. Westwick J, Watson-Williams EJ, Krishnamurthi S et al. Platelet activation during steady state sickle cell disease. J Med 1983;14:17-36. Wun T, Paglieroni T, Rangaswami A et al. Platelet activation in patients with sickle cell disease. Br J Haematol 1998;100:7419. Wun T, Paglieroni T, Tablin F et al. Platelet activation and platelet-erythrocyte aggregates in patients with sickle cell anemia. J Lab Clin Med 1997;129:507-16. Villagra JD, Shiva S, Hunter LA, Machado RF, Gladwin MT, Kato GJ. Platelet activation in patients with sickle disease, hemolysis-associated pulmonary hypertension and nitric oxide scavenging by cell-Free hemoglobin. Manuscript submitted. Jin RC, Voetsch B, Loscalzo J. Endogenous mechanisms of inhibition of platelet function. Microcirculation 2005;12:24758. Singer ST, Kuypers FA, Styles L et al. Pulmonary hypertension in thalassemia: Association with platelet activation and hypercoagulable state. Am J Hematol 2006;81:670-5. Kato GJ, McGowan V, Machado RF, et al. Lactate dehydrogenase as a biomarker of hemolysis-associated nitric oxide resistance, priapism, leg ulceration, pulmonary hypertension, and death in patients with sickle cell disease. Blood 2006;107:2279-85. Kato GJ, Gladwin MT, Steinberg MH. Deconstructing sickle cell disease: Reappraisal of the role of hemolysis in the development of clinical subphenotypes. Blood Rev 2007;21:37-47. Machado RF, Anthi A, Steinberg MH et al. N-terminal probrain natriuretic peptide levels and risk of death in sickle cell disease. JAMA 2006;296:310-8. Machado RF, Gladwin MT. Chronic sickle cell lung disease: new insights into the diagnosis, pathogenesis and treatment of pulmonary hypertension. Br J Haematol 2005;129:449-64. Machado RF, Martyr S, Kato GJ et al. Sildenafil therapy in patients with sickle cell disease and pulmonary hypertension. Br J Haematol 2005;130:445-53. Derchi G, Forni GL, Formisano F et al. Efficacy and safety of sildenafil in the treatment of severe pulmonary hypertension in patients with hemoglobinopathies. Haematologica 2005;90:452-8. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 139 | Sickle Cell Disease The contribution of asthma to sickle cell diseaserelated morbidity and mortality M.R. DeBaun1 J.E. Jennings1 J.H. Boyd1 J.J. Field2 C. Hillery3 R.C. Strunk1 1 Department of Pediatrics, Washington University School of Medicine, St. Louis; 2 Department of Internal Medicine, Washington University School of Medicine, St. Louis; 3 Department of Pediatrics, Medical College of Wisconsin, Milwaukee Wisconsin, USA Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:140-147 A B S T R A C T Pulmonary complications are the leading cause of death for individuals with sickle cell disease (SCD). Recently, asthma has been identified as a significant contributor to SCDrelated morbidity and mortality. Among children with SCD, asthma has been associated with an increased incidence of pain and acute chest syndrome (ACS) episodes when compared to children without asthma. Additionally, children and adults with SCD and asthma were noted to have a higher rate of death when compared to those without asthma. The proposed biological mechanism for the disease-modifying role of asthma in SCD is based on a combined inflammotory effect of the vasculature in SCD and the airways in asthma. Further, asthma results in ventilation-perfusion mismatch with regional hypoxia leading to an up-regulation of inflammatory proteins and increased adhesion of sickled red blood cells. This abnormal lung process accelerates the sickling process in the vascular beds which leads to vaso-occlusive episodes and other complications associated with SCD. This article will focus on the epidemiology, pathophysiology, and potential mechanisms for the association between asthma and SCD-related morbidity and mortality. omozygous sickle cell disease (SCD) results from a single nucleotide substitution at the 6th codon of the β-globin gene, yet SCD is rather heterogenic in terms of disease expression. The most common causes of disease-related morbidity are pain and ACS episodes. Pulmonary complications also contribute significantly to premature death. Although the relationship is not completely understood, asthma, bronchial hyperreponsiveness, and atopy are three overlapping clinical phenotypes that occur among individuals with SCD. When asthma is diagnosed among children with SCD there is an associated increase in the incidence of painful episodes, acute chest syndrome and death. We will review the epidemiology of how these separate clinical entities (Figure 1) influence the clinical course of individuals with SCD. H lence of approximately 20% in the USA. We are unaware of data relating to the prevalence of asthma in ethnic groups outside of the USA. The co-existence of asthma and SCD was first published in a 1983. This case report describes a six year-old girl with SCD and severe asthma who, several days following hospital admission for a slight worsening of her astmatic condition, developed abdominal pain that was identified as a vaso-occlusive episode.2 The authors believed the pain episode to be a result of asthma-induced hypoxia and acidosis due to ventilationperfusion mismatch. Although the exact mechanism has yet to be clarified, a complex interaction between SCD-related complications. Asthma and asthma risk factors such as atopy and bronchial hyperresponsiveness exists. Prevalence of asthma in patients with SCD Asthma in SCD Asthma is a chronic lung disease that affects approximately 9 million children in the USA.1 Asthma disproportionately affects African Americans with a preva| 140 | Diagnosis of asthma among children with SCD increases SCD-related complications. Although SCD and asthma are both common diseases among the African American population, conflicting evidence Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 exists as to whether asthma is more common among children with SCD. In a case control study, Madden et al.3 demonstrated that children with SCD have a two times greater risk of developing asthma compared children without SCD (48% vs. 22%, p=0.002). In contrast, in cohort study of children with SCD from birth to approximately 12 years of age, Boyd et al.7 demonstrated that in the absence of a diagnosis of ACS, the prevalence of asthma does not differ from that of the general African-American population (17.1%). Each study has limitations. Madden et al.3 reported a high rate of asthma when compared to other epidemiological surveys which suggests a selection bias. The study by Boyd et al.7 lacked prevalence data obtained from concurrent ethnic-matched controls. Atopy Asthma Phenotype Bronchial HyperResponsiveness SCD Morbidity Asthma increases SCD morbidity and mortality Pain and ACS episodes are common manifestations of SCD among children. Many studies support the contributory effect asthma has on SCD-related complications, especially pulmonary complications (Tables 1 and 2). Painful episodes in SCD can be precipitated by known triggers, such as dehydration and cold exposure, but many precipitating factors remain unknown. In a prospective infant cohort study of 291 infants followed for a total of 4,062 patient-years,4 Boyd et al. demonstrated a two-fold increase in the incidence of pain episodes in individuals with SCD and asthma compared to SCD alone (1.39 vs. 0.47 events per patient years p=0.001) (Figure 2). Boyd et al., adjusted their risk analysis for established factors associated with pain (age, gender, lifetime average hemoglobin and percent fetal hemoglobin) thus Figure 1. Proposed relationship between atopy, bronchial hyperreponsiveness, asthma phenotype, and SCD morbidity. The intersection of the asthma phenotype, bronchial hyper-responsiveness and atopy are thought to increase the rate of sickle cell disease morbidity. For the moment, no studies have demonstrated whether children with SCD and asthma risk factors have an increased rate of pain or ACS episodes. strengthening the evidence of their findings.5 Furthermore, among children with SCD and asthma, mild respiratory symptoms either immediately precede or occur simultaneously with painful episodes more frequently when compared to with children with SCD without asthma. Glassberg et al.6 showed that cough, wheeze, tachypnea, retractions, or grunting occurred within 96 hours prior to the Table 1. Influence of co-morbid conditions of SCD and asthma on the incidence or risk of painful episodes. Study Retrospective Study Nordness (2005) Case-control Glassberg (2006) Cohort Number of Participants (age range) Pain 96 (3-18 yrs of age) No significant difference in the rate of pain episodes in SCD and asthma vs. SCD alone 74 with SCD (2-21 yrs of age) Respiratory symptoms preceded pain episodes in patients with SCD and asthma vs. SCD alone 35% vs. 12%; p = 0.016 Respiratory symptoms were more likely to occur in association with a pain episode in children with SCD and asthma OR = 4.9 (95%CI:2.2-10.7) Increased incidence of pain in children with SCD and asthma 1.7 vs. 1.2 episodes per patient–years; p=0.005 Prospective Study Boyd (2006) Cohort 291 with SCD (<6 months-5 yrs of age) Increased incidence of pain in children with SCD and asthma 1.39 vs. 0.47 episodes per patient-years; p<0.001 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 141 | 12th Congress of the European Hematology Association Table 2. Influence of co-morbid conditions of SCD and asthma on the incidence or risk of acute chest syndrome (ACS). Number of participants (age range) Study Retrospective Boyd (2004) ACS and asthma 139 (2-21 yrs of age) Increased likelihood of developing ACS in children with SCD and asthma hospitalized for painful episode; OR = 4.0 (95%CI:1.7-9.5) Case-control Cases: ACS and pain Controls: no ACS and pain Knight-Madden (2005) Case-control 160 (5-10 yrs of age) Cases: SCD Controls: no SCD Recurrent ACS is associated with SCD and asthma; OR = 6.0 (95%CI:1.5-23.4) Nordness (2005) Case-control 96 (3-18 yrs of age) Cases: Asthma Controls: no Asthma ACS episodes are increased in children with SCD and asthma 7.5 vs.4.8 episodes per 100 patient-years; p=0.03 Bryant (2005) Descriptive 60 (1.5-17 yrs of age) SCD and ACS ACS develops in children with a prior history of asthma and/or abnormal pulmonary function tests 53% Sylvester (2007) Case-control 316 (0-18 yrs of age) Cases: SCD Controls: no SCD Increased anti-asthmatic medication use in children with a ACS history vs. no ACS history 18% vs. 5%; p=0.02 Asthma was diagnosed at a median of 3.5 (0.5-7) years prior to children developing the first ACS episode 291 (< 6 months – 5 yrs) Increased incidence of ACS in children with SCD and asthma vs. SCD alone; 0.39 vs. 0.20 episodes per patient-years; p<0.001 Prospective Study Boyd (2006) Cohort 400 Asthmatic Not Asthmatic Pain rate (/100 pt-yrs) 300 200 100 0 0-2 2-4 4-6 6-8 8-10 10-12 12-20 Age (yrs) Figure 2. Age-specific incidence of pain in the infant sickle cell anemia (SCA) cohort. An infant cohort of 291 African-American children with SCA enrolled in the Cooperative Study for Sickle Cell Disease (CSSCD) before six months of age and followed beyond five years of age for a total of 4,062 patient-years. A clinical diagnosis of asthma was made in 17% of the cohort. Overall incidence rate of painful events is higher in children with SCA and asthma (1.39 events/patient-year) when compared to children with SCA and without asthma (0.47 events/patient-year, p<0.001).*4 painful episode in children with SCD and asthma more frequently than in children with SCD alone (35% vs. 12%, p=0.016). Children with SCD and asthma were approximately five times more likely to have preceding or simultaneous respiratory symptoms associated with pain versus children with SCD only (95% confidence intervals, odds ratio 2.2-10). The incidence rate of painful episodes among children with SCD and asthma was higher compared to children with SCD but without asthma 1.7 vs 1.2 episodes per patient year respectively. ACS, defined as a new infiltrate on chest radiograph in combination with fever or respiratory symptoms, affects primarily the pediatric population with an incidence rate of 0.20 episodes per patient years.7 Similarly, asthma predominantly affects children. Sufficient clinical overlap exists between the presentation of an asthma exacerbation and ACS to obscure a clinical diagnosis. Specifically, a clinical diagnosis of ACS is associated with fever, tachypnea, wheezing, cough, new radiodenisty on chest X-ray and decreased oxygen saturation. As anticipated and based on the strong clinical and epidemiological overlap between the two co-morbidities ACS and an asthma exacerbation, diagnosis of asthma has been associated with an increased incidence of ACS. In a single center retrospective study, approximately 53% | 142 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 3. Prevalence of bronchial hyper-responsiveness (BHR) in children with sickle cell disease (SCD). Study Number of Participants (age range) BHR Assessment BHR prevalence (SCD vs. controls) Leong (1997) 50 (6-19 years of age) Bronchodilator Cold - air challenge SCD overall - 73% SCD and asthma - 83% SCD and no asthma - 64% Controls 0% Bronchodilator SCD - 54% Bronchodilator Exercise Test SCD - 44% Controls - 20% Cases: SCD and asthma SCD and no asthma Controls: No SCD and no asthma Koumbourlis (2001) 41 (5-18 years of age) SCD Knight-Madden (2005) 87 (5-10 years of age) Cases: SCD Controls: No SCD of children with SCD were noted to have a diagnosis of asthma or suggestive of obstructive airway disease prior to their first ACS episode.8 Boyd et al.9 demonstrated in a retrospective study that children with SCD and asthma had a four times greater risk of developing ACS after being hospitalized for pain compared to children with SCD alone (OR=4.0; 95%CI, 1.7-9.5). Longer hospitalizations for ACS were observed in children with SCD and asthma versus individuals with SCD alone (5.6 vs. 2.6 days, p=0.01). Due to the limitations of a retrospective study design, none of the before mentioned studies were able to establish a temporal relationship between asthma and ACS. Based on these studies, no data exist to determine whether asthma increases the incidence of ACS or if SCD increases the incidence of asthma exacerbations. Despite this, collectively these studies firmly establish a strong association between asthma and ACS. Additional evidence that there is an association between asthma and ACS episodes comes from Nordness et al.10 who conducted a retrospective chart review and found that patients with SCD and asthma had more episodes of ACS (7.5 vs. 4.8 episodes per 100 patient-years, p=0.03) than patients with SCD without asthma. Furthermore, this study illustrated that patients with both SCD and asthma had more disease- related complications with a resultant need for additional SCD treatment including, total blood transfusion, and chronic transfusion compared to controls. In the previously mentioned prospective infant cohort study, children with SCD and asthma were also younger at the time of their first ACS episode, median 2.4 years compared to 4.6 years of age for children with SCD without astma (hazard ratio 1.64, 95% CI 1.13 to 2.39, p=0.0096).4 Children with SCD and asthma also required more transfusions (1.00 per patient-year v. 0.60 per patient-year, p=0.02) than children with SCD without asthma.4 Sylvester et al.11 in a retrospective control study also found there was a higher prevalence of asthma among children who had a history of ACS. Specifically, 18% of the children that had an ACS episode were taking anti-asthmatic medication compared to 5% of the children with ACS that were not. Limited data exist regarding the affect of asthma on mortality among individuals with SCD. To date only one study addresses the association between asthma and SCD in terms of mortality. In a prospective cohort study (n=1963), Boyd et al.9 demonstrated that asthma was associated with a shortened life expectancy among individuals with SCD and asthma compared to SCD alone (52.2 years vs. 64.3 years). The existence of both SCD and asthma increased the risk of mortality by two-fold (hazard ratio 2.36, 95% CI 1.21-4.62, p=0.01). Bronchial hyperreponsiveness in SCD Bronchial hyper-responsiveness (BHR), a non-specific finding associated with asthma,10 also occurs in children without a clinical diagnosis of asthma. The presence of a positive BHR test is not a diagnosis of asthma. To diagnose asthma, the National Asthma Education and Prevention Program recommends obtaining a detailed medical history, physical examination, and pulmonary function testing to confirm airflow obstruction reversibility.12 In the absence of asthma, approximately 20% of children will have evidence of BHR.13 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 143 | 12th Congress of the European Hematology Association Bronchial hyper-responsiveness in children with SCD and without asthma The relationship between the presence of BHR and SCD-related pain or ACS is not known. Bronchial provocation tests such as bronchodilator challenges,3,14,15 exercise tests,3 methacholine tests,16 and cold air bronchial challenges14 have been used to assess BHR among children with SCD (Table 3). An increased rate of BHR has been demonstrated in children with SCD without a previous diagnosis of asthma when compared to controls. Leong et al.14 conducted a case-control study in children with SCD and no asthma compared to normal controls to determine the prevalence of BHR. Pulmonary function testing was performed in 22 cases and 10 controls. BHR was assessed in each participant using either the cold air challenge or bronchodilator challenge based on the forced expiratory volume in 1 second (FEV-1). Patients with SCD, but no history of wheezing, had a BHR prevalence of 64%. These results suggest an increased propensity to airway hyper-responsiveness even in the absence of a diagnosis of asthma. Cold air challenge is not specific for diagnosing asthma, thus results should be interpreted cautiously. Exposure to cold stimuli is known to precipitate sickling and a vaso-occlusive process that may have contributed significantly to bronchospasm. This is substantiated by the association of pain episodes with a decrease in ambient temperature,17 as well as an increase in forearm vascular resistance (an indicator of vasoconstriction) in patients with homozygous SCD compared to controls following repetitive exposure to cool immersion stimuli.18 Atopy in SCD A 10- to 20-fold increased risk of developing asthma occurs in the presence of atopy, as determined by skin testing.3 Savoy et al.19 reviewed medical records, questionnaires, and performed physical examinations to evaluate the prevalence of atopy (i.e. asthma, atopic dermatitis, and allergic rhinitis) in the SCD population. Overall the atopy prevalence was 13.7% in the SCD population with a similar rate in controls. Specifically, the prevalence of bronchial asthma, allergic rhinitis, and atopic dermatitis was not significantly different from that found in similar population studies. This observation was subsequently supported by KnightMadden et al.3 who demonstrated that the incidence of positive skin prick test performed in children with SCD was not significantly different compared to controls (36% vs. 34%, p=0.75). While these findings are suggestive of two independent events, this conclusion cannot be drawn because asthmatics are not always atopic. Pro-inflammatory status of SCD and its link to asthma Hypoxia-induced polymerization of HbS is the initial step in occlusion of the vasculature by red blood cells, ultimately leading to tissue injury. While the exact mechanism of vaso-occlusion is poorly defined, it involves a complex interaction of sickle and nonsickle erythrocytes, leukocytes, platelets, and vascular endothelial cells.20,21 Inflammatory mediators are the driving force behind these cellular interactions through the up-regulation of adhesion molecules (see also Kato and Gladwin, this book). At baseline, SCD is a pro-inflammatory state, based on systemic increases in inflammatory markers such as leukocyte count,22,23 platelet count,24 C-reactive protein,25-27 and cytokines.28-31 Inflammatory mediators stimulate an elevation in up-regulation of intracellular adhesion molecules (I-CAM), vascular adhesion molecules (V-CAM), and selectins.20 Expression of these adhesion molecules promotes the interaction of less deformable sickle erythrocytes with endothelial cells. More specifically, significant evidence suggests that sickled red blood cells result in continued injury to the endothelium resulting in tissue specific inflammation. Circulating endothelial cells and endothelial cell molecules (I-CAM, V-CAM, and E-selectin) in the plasma provide evidence of this vascular injury.32 Non-sickle erythrocytes, leukocytes, and platelets also bind to the activated endothelium of the microvasculature with resultant occlusion. Upon reperfusion, activated leukocytes and radical oxygen species released during tissue hypoxia further increase cellular damage and inflammation. This added elevation of inflammatory mediators further promotes endothelial cell activation, and thus propagates a cycle of inflammation, tissue injury, and vasoocclusion. Analogous to chronic endothelial inflammation in SCD is chronic airway inflammation in asthma. The stimulus for inflammation associated with asthma is an interaction between an airway allergen and a specific IgE on the surface of airway mast cells, which triggers the release of IL-4, IL-5, GM-CSF, histamine, and leukotrienes.33 IL-5 stimulates the bone marrow to increase eosinophil production, and circulating eosinophils bind to vascular endothelium through cell surface adhesion molecules.34 Inflammatory mediators associated with asthma up-regulate the expression of adhesion molecules to increase the eosinophil-endothelial cell interaction.35 Following attachment to the endothelium, eosinophils migrate into airway tissues, inflicting injury and perpetuating the inflammation that is characteristic of asthma. Despite the observation that the primary basis for inflammation differs between SCD and asthma, inflammation is fundamental to the pathophysiology of both disease processes. Furthermore, elevations of | 144 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 4. Elevated inflammatory markers common to sickle cell disease and asthma. Inflammatory Markers Sickle Cell Disease Asthma IL-5 Walter (2006) Br J Haematol39 Hoekstra (1997) Clin Exp Allergy40 sICAM-1 Shiu (2000) Blood Oymar (1998) Ped Allergy Immunol42 El Sawy (1999) Int. Arch Allergy43 Marquet (2000) Am J Respir Crit Care Med44 sVCAM-1 Duits (1996) Clin Immunol and Immunopathol45 Sakhalkar (2004) Am J Hematol46 Tang (2002) Pediatr Pulmonol47 Hamzaoui (2001) Mediators Inflamm48 Koizumi (1995) Clin Exp Immunol49 TNF-α Malave (1993) Acta Haematol29 Halasz (2003) Allergy Asthma Proc50 Koizumi (1995) Clin Exp Immunol49 Baysigit (2004) Mediators Inflamm51 LTB4 Setty (2002) J Lab Clin Med52 Baysigit (2004) Mediators Inflamm51 CRP Hedo (1993) J Intern Med25 Hibbert (2004) Exp Bio Med53 Sinn (2004) Am J Respir Crit Care Med54 eNO Pawar (2006) Pediatr Blood Cancer55 Girgis (2003) Am J Hematol56 Sullivan (2001) Am J Respir Crit Care Med57 Beck-Ripp (2002) Eur Respir J58 Kelly (2006) J Allergy Clin Immunol59 41 similar systemic inflammatory markers have been observed in both diseases (Table 4). Thus, we think that the combination of inflammatory processes in SCD and asthma together contribute to the increase in the rate of SCD-related complications, pain and ACS. Anti-inflammatory medication in the treatment of SCDrelated complications Additional evidence of a pro-inflammatory state in SCD is based on the quick return to baseline in individuals with either painful episodes or ACS after treatment with steroids for their systemic antiinflammatory effects. Two separate trials have been conducted using steroids to treat pain or ACS in SCD. A double-blind placebo-controlled study by Griffin et al.36 was conducted to determine the effect of intravenous methylprednisolone on children and adolescents with SCD (n=36) hospitalized for acute pain episodes. Duration of hospital stay was significantly shorter in patients receiving IV methylprednisolone compared to those receiving placebo (mean, 41.3 vs. 71.3 hours; p=0.030). Recurrence of pain leading to hospital readmission within two weeks of discharge was observed in approximately 15% of patients in the methylprednisolone study group (n=4) compared to 3% in the placebo group (n=1). Bernini et al.37 evaluated the efficacy and toxicity of IV dexamethasone in children with SCD hospitalized for ACS episodes (n=43) in a randomized, doubleblind placebo-controlled study. Hospital stay among patients in the dexamethasone group was shorter compared to the placebo group (mean hospital dura- tion: 47 hours vs. 80 hours; p=0.005). The dexamethasone group was also observed to have less clinical deterioration and a decreased need for blood transfusion (p<.001 and =0.013, respectively). Additionally, the mean duration of oxygen therapy, analgesic therapy, number of opioid doses, and duration of fever was significantly reduced in the dexamethasone group compared to the placebo group. Although not statistically significant, seven patients were readmitted within 72 hours, 6 patients from the dexamethasone treated group (27%) compared to one patient in the placebo group (4.7%), after hospital discharge. Only one patient was readmitted for an ACS episode within this group. Similar to the treatment of asthma, both studies provide evidence that anti-inflammatory therapy may be beneficial in the treatment of acute complications of SCD. However, the use of corticosteroids during the acute illness, particularly for patients with ACS and without a previous diagnosis of asthma, must be measured against the more recent evidence that the use of corticosteroids is temporally associated with cerebral hemorrhage in children with ACS38 and the high rate of readmission shortly after discharge.37 Summary This review describes the epidemiology of asthma and its associated increased rate of co-morbidity among children with SCD. Among children with SCD and asthma, the clinical management of SCD should include adherence to evidence-based practice of clinical care for asthma. Future research should be directed at clarifying the mechanism for this associa- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 145 | 12th Congress of the European Hematology Association tion. With a better understanding of the association between SCD and asthma, targeted therapy can be developed to decrease the morbidity and mortality linked to SCD. Acknowledgments Funded by: National Heart, Lung and Blood Institute, contract N01-HB-47110, RO1 HL079937 (MD, RS), Doris Duke Foundation (JJ), T32 HL07873 (JHB). References 1. Bloom B, Dey AN. Summary health statistics for U.S. children: National Health Interview Survey, 2004. Vital Health Stat 10. 2006;227:1-85. 2. Perin RJ, McGeady SJ, Travis SF, Mansmann HC Jr. Sickle cell disease and bronchial asthma. Ann Allergy. 1983;50:320-2. 3. Knight-Madden JM, Forrester TS, Lewis NA, Greenough A. Asthma in children with sickle cell disease and its association with acute chest syndrome. Thorax 2005;60:206-10. 4. Boyd JH, Moinuddin A, Strunk RC, DeBaun MR. Asthma and acute chest in sickle-cell disease. Pediatr Pulmonol 2004; 38:229-32. 5. Platt OS, Thorington BD, Brambilla DJ, Milner PF, Rosse WF, Vichinsky E, et al. Pain in sickle cell disease. Rates and risk factors. N Engl J Med 1991;325:11-6. 6. Glassberg J, Spivey JF, Strunk R, Boslaugh S, DeBaun MR. Painful episodes in children with sickle cell disease and asthma are temporally associated with respiratory symptoms. J Pediatr Hematol Oncol 2006;28:481-5. 7. Boyd JH, Macklin EA, Strunk RC, DeBaun MR. Asthma is associated with acute chest syndrome and pain in children with sickle cell anemia. Blood 2006;108:2923-7. 8. Bryant R. Asthma in the pediatric sickle cell patient with acute chest syndrome. J Pediatr Health Care 2005;19:157-62. 9. Boyd JN, Mackin EA, Strunk R, DeBaun M. Asthma is associated with an increased rate of acute chest syndrome, pain, and death in children with sickle cell anemia. Haematologica accepted for publication. 10. Nordness ME, Lynn J, Zacharisen MC, Scott PJ, Kelly KJ. Asthma is a risk factor for acute chest syndrome and cerebral vascular accidents in children with sickle cell disease. Clin Mol Allergy 2005;3:2. 11. Sylvester KP, Patey RA, Broughton S, Rafferty GF, Rees D, Thein SL, et al. Temporal relationship of asthma to acute chest syndrome in sickle cell disease. Pediatr Pulmonol 2007;42:1036. 12. National Institutes of Health. National Asthma Education and Prevention Program. Expert panel report 2: guidelines for the diagnosis and management of asthma. In: National Heart L, and Blood Institute, editor 1997. 13. Weiss ST, Tager IB, Weiss JW, Munoz A, Speizer FE, Ingram RH. Airways responsiveness in a population sample of adults and children. Am Rev Respir Dis. 1984;129:898-902. 14. Leong MA, Dampier C, Varlotta L, Allen JL. Airway hyperreactivity in children with sickle cell disease. J Pediatr 1997;131: 278-83. 15. Koumbourlis AC, Zar HJ, Hurlet-Jensen A, Goldberg MR. Prevalence and reversibility of lower airway obstruction in children with sickle cell disease. J Pediatr 2001;138:188-92. 16. Vendramini EC, Vianna EO, De Lucena Angulo I, De Castro FB, Martinez JA, Terra-Filho J. Lung function and airway hyperresponsiveness in adult patients with sickle cell disease. Am J Med Sci 2006;332:68-72. 17. Amjad H, Bannerman RM, Judisch JM. Letter: Sickling pain and season. Br Med J 1974;2:54. 18. Mohan J, Marshall JM, Reid HL, Thomas PW, Hambleton I, Serjeant GR. Peripheral vascular response to mild indirect cooling in patients with homozygous sickle cell (SS) disease and the frequency of painful crisis. Clin Sci (Lond). 1998;94: 111-20. 19. Savoy LB, Lim JD, Sarnaik SA, Jones DC. Prevalence of atopy in a sickle-cell anemia population. Ann Allergy 1988;61:129-32. 20. Okpala I. Leukocyte adhesion and the pathophysiology of sickle cell disease. Curr Opin Hematol. 2006 Jan;13(1):40-4. 21. Hebbel RP, Vercellotti GM. The endothelial biology of sickle cell disease. J Lab Clin Med 1997;129:288-93. 22. Awogu AU. Leucocyte counts in children with sickle cell anaemia: usefulness of stable state values during infections. West Afr J Med 2000;19:55-8. 23. West MS, Wethers D, Smith J, Steinberg M. Laboratory profile of sickle cell disease: a cross-sectional analysis. The Cooperative Study of Sickle Cell Disease. J Clin Epidemiol 1992; 45:893-909. 24. Okpala I. Steady-state platelet count and complications of sickle cell disease. Hematol J 2002;3:214-5. 25. Hedo CC, Aken'ova YA, Okpala IE, Durojaiye AO, Salimonu LS. Acute phase reactants and severity of homozygous sickle cell disease. J Intern Med 1993;233:467-70. 26. Singhal A, Doherty JF, Raynes JG, McAdam KP, Thomas PW, Serjeant BE, et al. Is there an acute-phase response in steadystate sickle cell disease? Lancet 1993;341:651-3. 27. Stuart J, Stone PC, Akinola NO, Gallimore JR, Pepys MB. Monitoring the acute phase response to vaso-occlusive crisis in sickle cell disease. J Clin Pathol 1994;4:166-9. 28. Francis RB Jr, Haywood LJ. Elevated immunoreactive tumor necrosis factor and interleukin-1 in sickle cell disease. J Natl Med Assoc 1992;84:611-5. 29. Malave I, Perdomo Y, Escalona E, Rodriguez E, Anchustegui M, Malave H, et al. Levels of tumor necrosis factor alpha/cachectin (TNF alpha) in sera from patients with sickle cell disease. Acta Haematol 1993;90:172-6. 30. Croizat H. Circulating cytokines in sickle cell patients during steady state. Br J Haematol 199487:592-7. 31. Kuvibidila S, Gardner R, Ode D, Yu L, Lane G, Warrier RP. Tumor necrosis factor alpha in children with sickle cell disease in stable condition. J Natl Med Assoc 1997;89:609-15. 32. Solovey A, Lin Y, Browne P, Choong S, Wayner E, Hebbel RP. Circulating activated endothelial cells in sickle cell anemia. N Engl J Med 1997;337:1584-90. 33. Busse WW, Lemanske RF Jr. Asthma. N Engl J Med 2001; 344:350-62. 34. Sanderson CJ. Interleukin-5, eosinophils, and disease. Blood 1992;79:3101-9. 35. Bochner BS, Klunk DA, Sterbinsky SA, Coffman RL, Schleimer RP. IL-13 selectively induces vascular cell adhesion molecule-1 expression in human endothelial cells. J Immunol 1995;154: 799-803. 36. Griffin TC, McIntire D, Buchanan GR. High-dose intravenous methylprednisolone therapy for pain in children and adolescents with sickle cell disease. N Engl J Med 1994;330:733-7. 37. Bernini JC, Rogers ZR, Sandler ES, Reisch JS, Quinn CT, Buchanan GR. Beneficial effect of intravenous dexamethasone in children with mild to moderately severe acute chest syndrome complicating sickle cell disease. Blood 1998;92:3082-9. 38. Strouse JJ, Hulbert ML, DeBaun MR, Jordan LC, Casella JF. Primary hemorrhagic stroke in children with sickle cell disease is associated with recent transfusion and use of corticosteroids. Pediatrics 2006;118:1916-24. 39. Walter PB, Fung EB, Killilea DW, Jiang Q, Hudes M, Madden J, et al. Oxidative stress and inflammation in iron-overloaded patients with beta-thalassaemia or sickle cell disease. Br J Haematol 2006;135:254-63. 40. Hoekstra MO, Hoekstra Y, De Reus D, Rutgers B, Gerritsen J, Kauffman HF. Interleukin-4, interferon-gamma and interleukin-5 in peripheral blood of children with moderate atopic asthma. Clin Exp Allergy 1997;27:1254-60. 41. Shiu YT, Udden MM, McIntire LV. Perfusion with sickle erythrocytes up-regulates ICAM-1 and VCAM-1 gene expression in cultured human endothelial cells. Blood 2000;95:3232-41. 42. Oymar K, Bjerknes R. Differential patterns of circulating adhesion molecules in children with bronchial asthma and acute bronchiolitis. Pediatr Allergy Immunol 1998;9:73-9. 43. El-Sawy IH, Badr-El-Din OM, El-Azzouni OE, Motawae HA. Soluble intercellular adhesion molecule-1 in sera of children with bronchial asthma exacerbation. Int Arch Allergy Immunol. 1999;119:126-32. 44. Marguet C, Dean TP, Warner JO. Soluble intercellular adhesion molecule-1 (sICAM-1) and interferon-gamma in bronchoalveolar lavage fluid from children with airway diseases. Am J Respir Crit Care Med 2000;162:1016-22. 45. Duits AJ, Pieters RC, Saleh AW, van Rosmalen E, Katerberg H, Berend K, et al. Enhanced levels of soluble VCAM-1 in sickle cell patients and their specific increment during vasoocclusive crisis. Clin Immunol Immunopathol 1996;81:96-8. 46. Sakhalkar VS, Rao SP, Weedon J, Miller ST. Elevated plasma | 146 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 47. 48. 49. 50. 51. 52. sVCAM-1 levels in children with sickle cell disease: impact of chronic transfusion therapy. Am J Hematol 2004;76:57-60. Tang RB, Chen SJ, Soong WJ, Chung RL. Circulating adhesion molecules in sera of asthmatic children. Pediatr Pulmonol 2002;33:249-54. Hamzaoui A, Ammar J, El Mekki F, Borgi O, Ghrairi H, Ben Brahim M, et al. Elevation of serum soluble E-selectin and VCAM-1 in severe asthma. Mediators Inflamm 2001;10:33942. Koizumi A, Hashimoto S, Kobayashi T, Imai K, Yachi A, Horie T. Elevation of serum soluble vascular cell adhesion molecule1 (sVCAM-1) levels in bronchial asthma. Clin Exp Immunol. 1995;101:468-73. Halasz A, Cserhati E, Kosa L, Cseh K. Relationship between the tumor necrosis factor system and the serum interleukin-4, interleukin-5, interleukin-8, eosinophil cationic protein, and immunoglobulin E levels in the bronchial hyperreactivity of adults and their children. Allergy Asthma Proc 2003;24:111-8. Basyigit I, Yildiz F, Ozkara SK, Boyaci H, Ilgazli A. Inhaled corticosteroid effects both eosinophilic and non-eosinophilic inflammation in asthmatic patients. Mediators Inflamm 2004;13:285-91. Setty BN, Stuart MJ. Eicosanoids in sickle cell disease: potential relevance of neutrophil leukotriene B4 to disease pathophysiology. J Lab Clin Med 2002;139:80-9. 53. Hibbert JM, Hsu LL, Bhathena SJ, Irune I, Sarfo B, Creary MS, et al. Proinflammatory cytokines and the hypermetabolism of children with sickle cell disease. Exp Biol Med (Maywood) 2005;230:68-74. 54. Sin DD, Lacy P, York E, Man SF. Effects of fluticasone on systemic markers of inflammation in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2004;170:760-5. 55. Pawar SS, Panepinto JA, Brousseau DC. The effect of acute pain crisis on exhaled nitric oxide levels in children with sickle cell disease. Pediatr Blood Cancer 2006 Apr 17. 56. Girgis RE, Qureshi MA, Abrams J, Swerdlow P. Decreased exhaled nitric oxide in sickle cell disease: relationship with chronic lung involvement. Am J Hematol 2003;72:177-84. 57. Sullivan KJ, Kissoon N, Duckworth LJ, Sandler E, Freeman B, Bayune E, et al. Low exhaled nitric oxide and a polymorphism in the NOS I gene is associated with acute chest syndrome. Am J Respir Crit Care Med 2001;164:2186-90. 58. Beck-Ripp J, Griese M, Arenz S, Koring C, Pasqualoni B, Bufler P. Changes of exhaled nitric oxide during steroid treatment of childhood asthma. Eur Respir J 2002;19:1015-9. 59. Kelly MM, Leigh R, Jayaram L, Goldsmith CH, Parameswaran K, Hargreave FE. Eosinophilic bronchitis in asthma: a model for establishing dose-response and relative potency of inhaled corticosteroids. J Allergy Clin Immunol 2006;117:989-94. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 147 | Sickle Cell Disease Hydroxyurea: benefits and risks in patients affected with sickle cell anemia M. de Montalembert Service de Pédiatrie Générale, Hôpital Necker, Paris, France Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:148-153 ydroxyurea is increasingly being used to treat patients with sickle cell anemia (SCA). A recent survey of 1,673 North-American patients enrolled in the NIH-NHLBI funded Comprehensive Sickle Cell Centers Program, found that 18% of children and 41% of adults were treated with hydroxyurea.1 Approximately 10 years after the major publication by Charache et al.2 reporting the benefits related to hydroxyurea treatment, more than 1,000 SCA patients are currently being treated in the world. H Mechanisms of action of hydroxyurea Hydroxyurea is a cytostatic agent (Sphase inhibitor) that was first used to treat myeloproliferative diseases. It is hypothesized that hydroxyurea increases fetal hemoglobin (HbF) (α2γ2) production through recruitment of new stem cells, since the gamma globin expression of such progenitors is still present. Higher HbF levels are known to be associated with an alleviation of the severity of SCA. Saudi Arabian patients have high HbF levels with a milder disease, SCA newborns do not experience complications, and in the Cooperative Study of Sickle Cell Disease, the mortality rate and frequency of painful crises were inversely correlated with HbF concentration.3,4 The clinical and pathological features of SCA are related to the occlusion of the vessels of the microcirculation by red cells sickled and stiffened after polymerization of the abnormal hemoglobin S upon deoxygenation. There is a time delay before polymerization occurs. This time delay increases when the proportion of HbF is raised, because in a mixture of hemoglobin S (HbS) (α2β2S) and HbF, there is a third tetrameric species, the hybrid (α2βSγ), which co-polymerizes very poorly with the others. As a result, red cells are able to exit from the capillary network before polymerization occurs.5 | 148 | These biophysical and clinical findings have led to a the search for ways of stimulating HbF synthesis to treat SCA. In a study exploring the effects of hydroxyurea in 3 SCA patients treated over 24 weeks, sickle hemoglobin polymerization delay time increased by at least four times after 12 weeks of treatment, and by approximately another two times after the second 12 week treatment period.6 Furthermore, as noted by others,7 increased K+ content and decreased K-Cl cotransport after 12 weeks of therapy indicated an improvement in red cell hydration status. The earliest effect was the striking decrease in erythrocyte adhesiveness to endothelial cells within 2 weeks of therapy. This is consistent with the observation that clinical improvement precedes HbF increase, and that HbF change is not correlated with clinical benefit,8 suggesting additional mechanisms are involved. Investigators have shown that hydroxyurea reduces expression of very late activation antigen-4 and CD36 on sickle reticulocytes,9 and that hydroxyurea therapy decreases the in vitro adhesion of sickle erythrocytes to thrombospondin and laminin.10 It is highly likely that Hydroxyurea also acts via a decrease of polymorphonuclear neutrophil (PMN) adhesion to endothelial cells which contributes to vascular inflammation and vaso-occlusion. Hydroxyurea decreases the PMN count wich is the measurement most strongly related to the beneficial effect of the drug,11 and as evidenced by a correction of dysregulated L-selectin expression and increased H2O2 production in SCA patients.12 It has also been shown that hydroxyurea enhances NO and cGMP production in endothelial cells in a cAMP-dependent protein kinase manner, which could participate in the induction of HbF as well as in the modification of vascular tone.13 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Clinical efficacy of hydroxyurea Short-term and median-term (1 to 5 years of treatment) controlled trials The Multicenter Study of Hydroxyurea (MSH) in sickle cell anemia2 This double-blind randomized study, enrolled SCA adult patients with severe disease (at least 3 painful crises per year). It assigned hydroxyurea to 152 patients and placebo to 147 controls. Patients given hydroxyurea received an initial dose of 15 mg/kg/day. This was increased by 5 mg /kg/d every 12 weeks unless marrow depression occurred (indicated by neutrophil count <2.0×109/L, reticulocyte or platelet count <80×109/L, or Hb level <4.5 g/dL). In the case of marrow depression, treatment was stopped until the blood count recovered and was then resumed at a dose 2.5 mg/kg lower than that associated with marrow depression. This defined the maximum tolerated dose (MTD). The hydroxyureatreated patients had a lower annual rate of crises than the controls (2.5 vs 4.5 crises per year, p<0.001), fewer patients had chest syndrome (25 vs 51, p <0.001), and fewer underwent transfusions (48 vs 73, p=0.001). Treatment was stopped after a mean follow-up of 21 months because of the benefits observed in the treated patients. The Belgian pediatric trial14 Twenty-five children (median age 9 years) were randomized to receive either hydroxyurea or placebo for 6 months, and then switched to the other arm for the next 6 months. The initial dosage was 20 mg/kg/d, increased to 25 mg/kg/d after 2 months if no increase of HbF level >2% had occurred. No attempt was made to reach the MTD. Among the 22 evaluable patients (median age 8 years) hydroxyureatreated children had significantly less hospitalizations (p=0.0016) and fewer hospitalized days (p= 0.0027). Short-term and median-term (1 to 5 years of treatment) non controlled trials A Cochrane review15 focused on the use of hydroxyurea in SCA patients. It included studies involving homozygous SS and Sbeta thalassemic adults16-18 and children,19-23 and even very young children.24 All of the studies but the last one enrolled patients with severe forms of disease. North-American studies increased the hydroxyurea dosage up to the MTD (the median dosage in Kinney’s study was 26±6.2 mg/kg/d), whereas European studies usually kept the dosage around 20 mg/kg/d. The drug was provided in 500 mg capsules for adults and older children, and in a liquid formula prepared by dissolution of the capsules for young children. All the studies reported increases in HbF, MCV and steady-state Hb, decrease of PMN, along with improvement in the number of painful crises, hospitalizations, and acute chest syndrome rates. However, clinical responses varied widely among patients and the best results were observed in children. Long-term trials There are no controlled long-term trials. One of the most important long-term studies is the extension of the MSH study conducted between 1992-1995. After completion of this initial study, patients were free to continue, start or stop treatment with hydroxyurea (25). Data for 233 patients were collected until 2001. Ninety-six patients (32%) never received hydroxyurea, 48 (16%) received hydroxyurea for less than 1 year, and 156 (52%) received hydroxyurea for 1 or more years. Twenty-five percent (n=75) of the 299 who originally volunteered for the MSH died during follow-up, 28% from pulmonary disease. Cumulative mortality at 9 years was inversely related to HbF level (p=0.03) and positively related to the occurrence of 1 or more episodes of acute chest syndrome during the trial (p=0.02). Hydroxyurea treatment was associated with a 40% reduction in mortality (p=0.04). Long-term studies on hydroxyurea use in children confirm a sustained efficacy in young patients. In the Belgian trial, there was a significant difference in the number of hospitalizations (p=0.0002) and hospitalized days (p<0.01) during 5-year treatment, compared to previous hydroxyurea therapy.26 The NorthAmerican Hydroxyurea Safety and Organ Toxicity (HUSOFT)24 which had included 28 infants was extended for up to 4 years for 17 patients and up to 6 years for 11 patients.27 Patients experienced 7.5 acute chest syndrome events/100 person-years, compared with 24.5 events/100 person-years among historical controls (p=0.001). Hydroxyurea-treated infants had a comparatively preserved splenic function compared to historical controls. The proportion of asplenic patients assessed by Tc-99m sulphur colloid uptake showed an absent uptake (i.e. functional asplenia) in 43% patients after study completion, versus the 94% percent standard for that age. Remarkably, two babies with markedly decreased or absent splenic uptake prior to hydroxyurea treatment recovered normal splenic uptake after 4 years of hydroxyurea. Biologically, all of the studies reported a long-term increase in Hb, MCV, and HbF levels, and a significant decrease in reticulocyte, PMN, and platelet counts.26-29 Increases in Hb and HbF levels were greater in the Duke cohort,29 where children received higher dosages (average dose: 25.4 mg±5.4 mg/kg/d, with 17% receiving more than 30 mg/kg/d) than in the Belgian cohort (where children received 20-25 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 149 | 12th Congress of the European Hematology Association mg/kg/d).26 The minimal HbF level increase needed to observe clinical benefit has not yet been determined, therefore no recommendation can be made for optimal dosage. Predictors of the response to hydroxyurea Clinical response to HU in SCA patients varies widely, with children generally experiencing greater benefits than adults. All of the patients in the Duke pediatric cohort responded,29 whereas half the adults in the Multicenter Study of Hydroxyurea showed an almost stable fetal hemoglobin level after 2 years,30 despite identical treatment protocols. Most probably, mothers’ compliance is greater than that of adult patients, but it cannot be excluded that children’s erythroid progenitors also have a greater capacity to increase HbF production than adult progenitors. It is impossible to predict individual response to treatment, regardless of patient age. To identify determinants of response, 150 HU-treated adult patients were grouped by quartiles of change in HbF from baseline to 2 years of treatment.30 In the top two quartiles, HbF increased to 18.1% and 8.8%. These patients had the highest baseline neutrophil and reticulocyte count and the largest treatmentassociated decrements in these counts. In the lower two quartiles, 2-year HbF levels (4.2% and 3.9%) and blood counts changed little from baseline. This finding suggests that the capacity of the bone marrow to withstand HU might be an important factor influencing response to treatment. In the quartile with the highest HbF response, myelosuppression developed in less than 6 months, compliance was greatest, and final doses were 15 to 22.5 mg/kg/d. All quartiles had substantial increases of F-cells (the HbF containing cells). These were maintained for 2 years only in the top three quartiles. HbF response was not associated with initial HbF in this study, but was highly related to initial HbF in others.21,29,32 Pharmacokinetic differences among individuals may account for the wide range of HbF response among SCA patients. We studied pharmacokinetic parameters in 15 adults and 11 children. Pharmacokinetics was not significantly different between adults and children but considerable individual variation was noted.33 Genetic factors modulating HbF response are most probably involved. In a study exploring the influence of 226 single nucleotide polymorphisms with possible roles in HbF regulation and hydroxyurea metabolism, aquaporin 9, a membrane channel that stimulates urea transport and allows the passage of uncharged solutes, and CYP2CP, a member of the cytochrome P450 family, appeared as possible modulators of HbF response to hydroxyurea.34 Safety of hydroxyurea treatment Short-term and mid-term safety The most frequently reported side effect is myelosuppression, which is usually transient and resolved by decreased dosage. Persistent pancytopenia has occasionally been reported,35 and there is one publication of an opportunistic infection occurring during hydroxyurea treatment.36 A complete blood count must be performed before starting treatment, 2 weeks after starting treatment, at 2-4 week intervals during the initial phase, and then every 6 weeks. These results should be monitored by a medical professional. Rash, dizziness, headache and asthenia have been reported, though these rarely led to cessation of treatment.37 Nail hyperpigmentation is common, and moderate alopecia can occur.37,38 The relationship with the development of leg ulcers is controversial, since leg ulcers are classic complications of SCA.39 One case of azoospermia has been reported in a SCA patient treated with hydroxyurea who before treatment had a normal spermatic fluid analysis. Azoospermia was reversible after stopping hydroxyurea.40 Many patients treated with hydroxyurea have had children during hydroxyurea treatment, but uncertainty remains over the long-term fertility of boys treated since childhood. Studies in rats showed an increase in fetal losses, and reduced fetal and placental weights.41 Although many healthy babies are now born from hydroxyurea-treated women, female patients should be informed of the theoretical risks of teratogenicity and advised to cease hydroxyurea treatment when planning a pregnancy. A study of infant mice exposed to high doses of hydroxyurea showed impaired brain and spleen growth in mice aged less than 8 days (equivalent to 2 years old in humans) when receiving the dose.42 These findings led most pediatricians to wait until the age of 2 to prescribe hydroxyurea. However, no toxicities, and in particular no growth abnormalities, have been reported in the trial in very young children.24 Hankins et al. have in fact reported improved growth in infants receiving hydroxyurea than in controls.27 In older children, hydroxyurea treatment had no adverse effect on height or weight gain or pubertal development.43 The possibility that hydroxyurea increases the risk of splenic sequestration in children is still under discussion. In fact, hydroxyurea has been shown to delay splenic infarction or even to restore splenic function in older patients.27,44,45 We reported 6 cases of hypersplenism leading to withdrawal of the drug in our cohort of 225 hydroxyurea-treated children, with recurrent splenic sequestration episodes in 2 homozygous for HbS children aged 6 and 7 years.37 In | 150 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 children, we therefore recommend careful monitoring of spleen size and blood tests at each evaluation particularly for children with prior splenomegaly or past history of splenic sequestration before starting hydroxyurea treatment. Compliance remains the most frequent problem encountered. Using analyses of laboratory parameters and review of peripheral blood smears (MCV increase in particular), and pill counts when possible, Zimmerman estimated that non-compliance led to hydroxyurea withdrawal in 12% of her pediatric patients.29 This percentage was 7.5% in our series.37 Table 1. Malignancies in SCD patients treated with hydroxyurea. ALL Ph + AML/MDS AML Hodgkin AML ALL Testis cancer Breast cancer Age (years) Duration of treatment Reference 10 27 42 8 21 14 39 58 7 weeks 8 years 6 years 6 months 8 years unknown unknown unknown 22 47 48 49 50 51 51 51 Long-term safety As discussed above, uncertainties remain as to the long-term consequences on fertility of boys treated with hydroxyurea for several years. Storage of frozen sperm must be proposed systematically to mature boys and adults, though this is rarely accepted. The risk of malignancies is also cause for concern Hemoglobinopathies are not thought to increase the risk of developing of secondary malignancies. A study of 64 patients treated for 2-15 years with hydroxyurea for cyanotic congenital heart disease showed no increased malignancy.46 So far, 8 malignancies have been reported in SCA patients receiving hydroxyurea (Table 1):22,47-51 Five cases have been published as single reports, 3 come from a NorthAmerican register which enrolled 16,613 SCA patients followed in 52 centers.51 Two (1 ALL, 1 Hodgkin disease) occurred in the first 6 months after starting treatment, reducing the probability that hydroxyurea is responsible for the malignancies. Three other hematological cases (3 AML) occurred after 6, 8, and 8 years of treatment. The register mentions one ALL occurring in a 14 year old child, testicular cancer in a 39 year old man, breast cancer in a 47 year old woman. However, time intervals between the start of hydroxyurea treatment and malignancy are not noted. While it is not possible to identify the role of hydroxyurea in the pathogenesis of these malignancies, great caution must be observed. In vitro, quantitative analyses of acquired DNA mutations suggest that the mutagenic potential of hydroxyurea is low.52 Indications for hydroxyurea treatment Randomized studies assessed the efficacy of hydroxyurea in preventing recurrences of painful crises in adults and children severely affected with SCA, and in adults with repeated episodes of acute chest syndrome. It seems reasonable to also expert such efficacy for prevention of acute chest syndrome recurrences, in children, although this has not been demonstrated by a pediatric controlled study. The Food and Drug Administration has approved its use in adult SCA patients with recurrent moderate to severe painful crises (at least 3 over 12 months), and European regulatory authorities are currently approving a coated breakable 1,000 mg tablet for patients with repeated vaso-occlusive events. However, hydroxyurea is currently used in many other indications. In addition to prevention of painful crises and acute chest syndromes, hydroxyurea is mainly used in adults with early chronic organ damage (respiratory, renal, hepatic, myocardial insufficiencies), or in association with an auto-immune disease requiring steroids, conditions for which chronic transfusion therapy was usually employed prior to the introduction of hydroxyurea. However, there has been no randomized study comparing transfusion to hydroxurea in these indications. The decision to use hydroxyurea or chronic transfusions is usually based on better tolerability to hydroxyurea treatment compared with chronic transfusions which carry the risk of allo-immunization, iron overload, venous access problems, and transfusion-related infections, particularly in developing countries. There are also some general reports of hydroxyurea use in children with hepatic53 or myocardial54 failure. Hydroxyurea is sometimes also prescribed in patients with severe anemia, after elimination of an aggravating factor such as iron or vitamin deficiency, inflammation, or renal insufficiency. It may be prescribed either systematically when Hb level is below 6 g/dL, or in patients whose tolerance of anemia is decreased. Erythropoietin is sometimes associated with hydroxyurea therapy in patients with pulmonary hypertension or mild renal insufficiency, since erythropoietin may allow more aggressive hydroxyurea dosing.55 The most controversial use of hydroxyurea is in the prevention of cerebro-vascular events. The pathophysiology of these events associates sickling and adhesion of sickle red cells to the vascular endothelium, progressive narrowing of the lumen of medium and large intracranial vessels leading to stenosis and occlusion, collateral circulation with moya-moya disease, microcirculation perfusion Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 151 | 12th Congress of the European Hematology Association defects, a procoagulant state, chronic hemolysis and abnormal vasomotor tone.56 Given that hydroxyurea improves deformability, decreases sickling and adhesion of red cells, and is probably a NO donor, a protective effect on the brain could be expected. In fact, two studies argue for this protective effect. Thirtyfour Belgian SCA children at high-risk of primary stroke on the basis of transcranial Doppler velocities (TCD) > 200 cm/s were given hydroxyurea rather than transfusion because of a high rate of allo-immunization. Only one of them experienced a cerebrovascular event (seizures) after a follow-up of 96 patient-years.28 Another study reports a stroke recurrence rate of 10% in 20 children who had had a stroke, had been transfused during a median period of 27±23 months, and had then discontinued transfusion and been treated with hydroxyurea after an overlap period of 6±3 months.57 However, there are many reports of cerebrovascular accidents, sometimes fatal, in patients receiving hydroxyurea.20,24,35,37,58 The incidence of stroke was identical in the treated and control groups in the MSH study.2 We therefore believe that chronic transfusion which keeps the HbS level permanently below <30%, whenever feasible and safe, remains the best option for children who have had an overt stroke, or who have abnormal TCD studies. One study reports stopping transfusion in 10 patients initially transfused for abnormal TCD, but without stroke history. After checking normalization of TCD velocities during transfusion and normality of MRA, hydroxyurea was prescribed after an overlap period with transfusions, and TCD measured every 3 months.59 Four of these ten patients redeveloped high velocities off transfusion and transfusions were therefore resumed. The other six remain transfusion-free after a mean follow-up of 4.4 years. This could suggest that i) hydroxyurea is better than no treatment at all after a stroke in countries without adequate blood supplies, ii) hydroxyurea may prevent a first overt stroke in patients with moderate narrowing of vessels lumen, but that iii) hydroxyurea is insufficient to prevent a stroke in patients with advanced cerebral vessel disease. It is not possible to say today whether hydroxyurea is an appropriate treatment for the 20% of SCD children and 40% of SCD adults who currently receive it. Efficacy and safety data are encouraging but we lack long-term follow-up on cohorts of patients with longterm exposure to the drug. Randomized studies are needed. We would like to conclude by quoting Charache: «We’d best be cautious in what we tell our patients and their parents. We can hold out our hope of improvement, but we should not promise it».60 The author is indebted to Sam Charache for his helpful comments. References 1. Rogers ZR, Lieff S, McMurray M, Dampier C, Wang WC, Chelednik M, et al. Collaborative Data Project [C-DATA] of the comprehensive Sickle Cell Centers Program. Blood 2006; 108:353a. 2. Charache S, Terrin ML, Moore RD, Dover GJ, Barton FB, Eckert SV, et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. N Engl J Med 1995; 332:1317-22. 3. Platt OS, Brambilla DJ, Rosse WF, Milner PF, Castro O, Steinberg MH, et al. Mortality in sickle cell disease: life expectancy and risk factors for early death. N Engl J Med 1994;330:1639-44. 4. Platt OS, Thorington BD, Brambilla DJ, Milner PF, Rosse WF, Vichinsky E, et al. Pain in sickle cell disease. Rate and risk factors. N Engl J Med 1991;325:11-6. 5. Eaton WA, Hofrichter J. The biophysics of sickle cell hydroxyurea therapy. Science 1995;268:1142-3. 6. Bridges KR, Barabino GD, Brugnara C, Cho MR, Christoph GW, Dover G, et al. A multiparameter analysis of sickle erythrocytes in patients undergoing hydroxyurea therapy. Blood 1996;88:4701-10. 7. Ballas SK, Dover GJ, Charache S. Effects of hydroxyurea on the rheological properties of sickle erythrocytes in vivo. Am J Hematol 1989;32:104-11. 8. De Montalembert M, Belloy M, Bernaudin F, Gouraud F, Capdeville R, Mardini R, et al. Three-year follow-up of hydroxyurea treatment in severely ill children with sickle cell disease. J Pediatr Hematol Oncol 1997;19:313-8. 9. Styles LA, Lubin B, Vichinsky E, Lawrence S, Hua M, Test S, et al. Decrease of very late activation antigen-4 and CD36 on reticulocytes in sickle cell patients treated with hydroxyurea. Blood 1997;89:2554-9. 10. Hillery CA, Du MC, Wang WC, Scott JP. Hydroxyurea therapy decreases the in vitro adhesion of sickle erythrocytes to thrombospondin and laminin. Br J Haematol 2000;109:322-7. 11. Charache S. Mechanism of action of hydroxyurea in the management of sickle cell anemia in adults. Semin Hematol 1997;34:15-21. 12. Benkerrou M, Delarche C, Brahimi L, Fay M, Vilmer E, Elion J, et al. Hydroxyurea corrects the dysregulated L-selectin expression and increased H2O2 production of polymorphonuclear neutrophils from patients with sickle cell anemia. Blood 2002;99:2297-303. 13. Cokic VP, Beleslin-Cokic BB, Tomic M, Stojilkovicz SS, Noguchi CT, Schechter AN. Hydroxurea induces the eNOScGMP pathway in endothelial cells. Blood 2006;108:184-9. 14. Ferster A, Vermylen C, Cornu G, Buyse M, Corazza F, Devalck C , et al. Hydroxyurea for treatment of severe sickle cell anemia: a pediatric clinical trial. Blood 1996;88:1960-4. 15. Davies SC, Olyjohungbe A. Hydroxyurea for sickle cell disease (Cochrane review). In: the Cochrane Library, Issue 3, 2002, Update Software, Oxford. 16. Kutlar A, Woods KF, Clair B, Daitch L, Milner PF, Samuels BJ, et al. Long-term use of hydroxyurea (HU. in adults with sickle cell disease (SS): a large single center experience. Blood 2000;96:10a. 17. Voskaridou E, Kalotychou V, Loukopoulos D. Clinical and laboratory effects of long-term administration of hydroxyurea to patients with sickle-cell/beta-thalassaemia. Br J Haematol 1995; 89:479-85. 18. Rigano P, Rodgers GP, Renda MC, Aquino A, Maggio A. Clinical and hematological responses to hydroxyurea in Sicilian patients with HbS/b-thalassemia. Hemoglobin 2001;25:9-17. 19. Jayabose S, Tugal O, Sandoval C, Patel P, Puder D, Lin T, et al. Clinical and haematological effects of hydroxyurea in children with sickle cell disease. J Pediatr 1996;129:559-65. 20. Scott JP, Hillery CA, Brown ER, Misiewicz V, Labotka RJ. Hydroxyurea therapy in children severely affected with sickle cell disease. J Pediatr 1996;128:820-8. 21. Kinney TR, Helms RW, O’Branski EE, Ohene-Frempong K, Wang WC, Daeschner C, et al. Safety of hydroxyurea in children with sickle cell anemia: results of the HUG-KIDS study, a phaseI/II trial. Blood 1999;94 :1550-4. 22. De Montalembert M, Bégué P, Bernaudin F, Thuret I, Bachir D, Micheau M. Preliminary report of a toxicity study of hydroxyurea in sickle cell disease. Arch Dis Child 1999;81:437-9. 23. Hoppe C, Vichinsky E, Quirolo K, Van Warmedam J, Allen K, Styles L. Use of hydroxyurea in children aged 2 to 5 years with sickle cell disease. J Pediatr Hematol Oncol 2000;22:330-4. | 152 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 24. Wang WC, Wynn LW, Rogers ZR, Scott JP, Lane PA, Ware RE. A two-year pilot trial of hydroxyurea in very young children with sickle-cell anemia. J Pediatr 2001;139:790-6. 25. Steinberg MH, Barton F, Castro O, Pegelow CH, Ballas SK, Kutlar A, et al. Effect of hydroxyurea on mortality and morbidity in adult sickle cell anemia. Risk and benefits up to 9 years of treatment. JAMA 2003;289:1645-51. 26. Ferster A, Tahriri P, Vermylen C, Sturbois G, Corazza F, Fondu P, et al. Five years of experience with hydroxyurea in children and young adults with sickle cell disease. Blood 2001;97:362832. 27. Hankins JS, Ware RE, Rogers ZR, Wynn LW, Scott JP, Wang WC. Long-term hydroxyurea therapy for infants with sickle cell anemia- the Husoft extension study. Blood 2005;106:226975. 28. Gulbis B, Haberman D, Dufour D, Christophe C, Vermylen C, Kagambega F, et al. Hydroxyurea for sickle cell disease in children and for prevention of cerebrovascular events. The Belgian experience. Blood 2005;105:2685-90. 29. Zimmerman SA, Schultz WH, Davis JS, Pickens CV, Mortier NA, Howard TA, et al. Sustained long-term efficacy of hydroxyurea at maximum tolerated dose in children with sickle cell disease. Blood 2004;103:2039-45. 30. Steinberg MH, Lu ZH, Barton FB, Terrin ML, Charache S, Dover GJ. Fetal hemoglobin in sickle cell anemia: determinants of response to hydroxyurea. Blood 1997;89:1078-88. 31. Maier-Redelsperger M, de Montalembert M, Flahaut A, Neonato MG, Ducrocq R, Masson MP, et al. Fetal hemoglobin and F-cell response to long-term hydroxyurea treatment in young sickle cell patients. Blood 1998;91:4472-9. 32. Ware RE, Eggleston B, Redding-Lallinger R, Wang WC, SmithWhitley K, Daescher C, et al. Predictors of fetal haemoglobin response in children with sickle cell anemia receiving hydroxyurea therapy. Blood 2002;99:10-4. 33. De Montalembert M, Bachir D, Hulin A, Gimeno L, Mogenet A, Bresson JL, et al. Pharmacokinetics of the 1,000 mg coated breakable tablets and 500 mg capsules in pediatric and adults with sickle cell disease Haematologica 2006;91:1685-8. 34. Wyszynski DF, Baldwin CT, Cleves MA, Farrell JJ, Bisbee A, Kutlar A, et al. Genetic polymorphisms associated with fetal haemoglobin response to hydroxyurea in patients with sickle cell anemia. Blood 2004;104: 34a. 35. Vichinsky EP, Lubin BH. A cautionary note regarding hydroxyura in sickle cell disease. Blood 1994;83: 1124-8. 36. Venigalla P, Motwani B, Nallari A, Allen S, Agarwal M, Alva M, et al. A patient on hydroxyurea for sickle cell disease who developed an opportunistic infection. Blood 2002;100: 363-4. 37. De Montalembert M, Brousse V, Elie C, Bernaudin F, Shi J, Landais P. Long-term hydroxyurea treatment in children with sickle cell disease:tolerance and clinical outcomes. Haematologica 2006;91:125-8. 38. O’Branski EE, Ware RE, Prose NS, Kinney TR. Skin and nail changes in children with sickle cell disease receiving hydroxyurea therapy. J Am Acad Dermatol 2001;44: 859-61. 39. Chaine B, Neonato MG, Girot R, Aractingi S. Cutaneous adverse reaction to hydroxyurea in patients with sickle cell disease. Archives of Dermatology 2001;137: 467-70. 40. Carozzo G, Disca S, Fidone C, Bonomo P. Azoospermia in a patient with sickle cell disease treated with hydroxyurea. Haematologica 2000;85:1216-8. 41. Spencer F, Chi L, Zhu MX. Hydroxyurea inhibition of cellular and developmental activities in the decidualized and pregnant uteri of rats. Journal of Applied Toxicology 2000;20:407-12. 42. Bennett T, Bal H, Chen Q, Abdulmalik O, Yang J, Iyamu E, et 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. al. Effects of orally-administered hydroxyurea on infant mice. Blood 2003;10:761a Wang WC, Helms RW, Lynn HS, Redding-Lallinger R, Gee B, Ohene-Frempong K, et al. Effect of hydroxyurea on growth in children with sickle cell anemia: results of the HUG-KIDS study. J Pediatr 2002;140:225-9. Claster S, Vichinsky E. First report of reversal of organ dysfunction in sickle cell anemia by the use of hydroxyurea: splenic regeneration. Blood 1996;88:1951-3. Santos A, Pinheiro V, Anjos C, Brandelise S, Fahel F, Lima M, et al. Scintigraphic follow-up of the effects of therapy with hydroxyurea on splenic function in patients with sickle cell disease. Eur J Nucl Med Mol Imaging 2002;29:536-41. Triadou P, Maier-Redelsperger M, Krishnamoorty R, Deschamps A, Casadevall N, Dunda O, et al. Fetal haemoglobin variations following hydroxyurea treatment in patients with cyanotic congenital heart disease. Nouv Rev Fr Hematol 1994;36:367-72. Rauch A, Borromeo M, Ghafoor A, Khoyratty B, Maheshwari J. Leukemogenesis of hydroxyurea in the treatment of sickle cell anemia. Blood 1999;84:415a . Wilson S. Acute leukaemia in a patient with sickle cell anemia treated with hydroxyurea. Ann Intern Med 2000;133:925-6. Moschovi M, Psychou F, Memegas D, Tsangari GT, Tzortzatou-Stathopoulou F, Nikolaidou P. Hodgkin’s disease in a child with sickle cell disease treated with hydroxyurea. Pediatr Hematol Oncol 2001;18:371-6. Ferster A, Sariban E, Meulemann N. Malignancies in sickle cell disease patients treated with hydroxyurea. Br J Haematol 2003;123:368-9. Schultz WH, Ware RE. Malignancy in patients with sickle cell disease. Am J Hematol 2003;74:249-53. Hanft VN, Fruchtman SR, Pickens CV, Rosse WF, Howard TA, Ware RE. Acquired DNA mutations associated with in vitro and in vivo hydroxyurea exposure. Blood 2000;95:3589-93. Jeng MR, Rieman MD, Naidu PE, Kaste SC, Jenkins III JJ, Serjeant G, et al. Resolution of chronic hepatic sequestration in a patient with homozygous sickle cell disease receiving hydroxyurea. J Pediatr Hematol Oncol 2003;25:257-60. De Montalembert M, Maunoury C, Acar P, Brousse V, Sidi D, Lenoir G. Myocardial ischemia in children with sickle cell disease. Arch Dis Child 2004;89:359-62. Little JA, McGowan VR, Kato GJ, Partovi KS, Feld JJ, Maric I, et al. Combination erythropoietin-hydroxyurea therapy in sickle cell disease: experience from the National Institutes of Health and a literature review. Haematologica 2006;91:107683. Switzer JA, Hess DC, Nichols FT, Adams RT. Pathophysiology and treatment of stroke in sickle-cell disease: present and future. Lancet Neurol 2006 5:501-12. Ware RE, Zimmerman SA, Sylvestre PB, Mortier NA, Davis JS, Treem WR, et al. Prevention of secondary stroke and resolution of transfusional iron overload in children with sickle cell anemia using hydroxyurea and phlebotomy. J Pediatr 2004;145:346-52. Bakanay SM, Dainer A, Clai B, Adekile A, Daitch L, Wells L, et al. Mortality in sickle cell patients on hydroxyurea therapy. Blood 2005;105:545-7. Bernaudin F, Verlhac S, Coic S, Lesprit E, Brugières P, Reinert P. Long-term follow-up of pediatric sickle cell disease patients with abnormal high velocities on transcranial Doppler. Pediatr Radiol 2005;35:242-8. Charache S. Who should get HU? And how? Blood 2002;99:1. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 153 | Acute Lymphoblastic Leukemia Genetics of T-cell acute lymphoblastic leukemia C.J. Harrison Leukaemia Research Cytogenetics Group, Cancer Sciences Division, University of Southampton, UK Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:154-160 -cell acute lymphoblastic leukemia (T-ALL) is a high risk malignancy of thymocytes, which accounts for approximately 15% of childhood and 25% of adult ALL.1 It is a heterogeneous disease, classified according to the expression of specific cytoplasmic or surface markers.2 The development of normal thymocytes and their regulation mechanisms have been studied extensively and it has been shown that the significant genes in T-cell development are also involved in T-ALL.3 This is supported by the gene expression signatures of T-ALL, which mirror the specific stages of thymocyte development.4 These observations indicate a multistep process of pathogenesis in T-ALL.3 De Keersmaecker et al.5 defined four pathways based on different classes of mutations that: 1) provide a proliferative advantage; 2) impair differentiation and survival; 3) affect the cell cycle; 4) provide self renewal capacity. The recurrent chromosomal abnormalities and molecular changes as defined within these pathways are described below and summarised in Table 1. T The role of cytogenetics and molecular analysis in the detection of mutations Cytogenetic analysis, and more recently fluorescence in situ hybridisation (FISH), have been instrumental in revealing chromosomal rearrangements, which have identified a number of important oncogenes in T-ALL. Visible chromosomal changes are seen in approximately 50% of T-ALL, while the remainder show a normal karyotype. Cryptic translocations, for example t(5;14)(q35;q32) involving TLX3, and deletions, such as TAL1, may be detected by FISH using appropriate probes6 (Figure 1). In T-ALL, translocations involving the T-cell receptor (TCR) loci, α (TRA@) and δ (TRD@), located to chromosomal band 14q11; β (TRB@) and γ (TRG@) located to 7q34 and 7p15, respectively, are found in approximately 35% of | 154 | T-ALL by FISH, many of which are cryptic at the cytogenetic level.7 Breakpoints within the TCR loci give rise to illegitimate recombination. This may result in oncogenes becoming juxtaposed to the promoter and enhancer elements of the TCR genes leading to their aberrant expression and the development of TALL. Alternatively, aberrant expression of oncogenic transcription factors may result from loss of the upstream transcriptional mechanisms that normally downregulate the expression of these oncogenes during T-cell development.8 The Krüppel-like zinc-finger gene, BCL11B, encodes a transcription factor essential in T-cell development.9 In the translocation, t(5;14)(q35;q32), BCL11B specifically associates with TLX3, leading to upregulation of TLX3.10 There are an increasing number of reports of the involvement of BCL11B in other rearrangements in T-ALL. For example, t(5;14)(q35.1;q32.2), in which NKX2-5, another homeobox gene, is upregulated,11 and inv(14)(q11.2q32.31), which results in expression of the BCL11B-TRD@ fusion in association with the absence of the wild type BCL11B transcript.12 A number of other novel BCL11B partners have been identified by FISH, which are in the process of being characterized.13 The interrelationships between the TCR genes, BCL11B and partners are shown in Figure 2. Alternatively, chromosomal rearrangements may produce fusion genes, formed by in frame fusion of part of the two partner genes located at the chromosomal breakpoints. The fusion gene encodes a new chimeric protein with oncogenic potential. Translocations of this type involving MLL fusions and PICALMMLLT10 (CALM-AF10) are classified among the mutations which impair differentiation, while those involving the tyrosine kinase, ABL1, play a role in the proliferation and survival pathway. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Four classes of mutations in the pathogenesis of T-ALL Mutations which impair differentiation Aberrant expression of one or more transcription factors is a critical component of the molecular pathogenesis of T-ALL. These include the class B basic helix-loop-helix (bHLH) genes: TAL1, TAL2, LYL1, bHLHB1 and MYC, as well as genes involved in transcription regulation, for example, the cysteinerich LIM-domain-only genes, LMO1 and LMO2. Abnormalities also affect the homeodomain genes, TLX1 and TLX3, and members of the HOXA cluster. The TAL1 gene maps to 1p32. TAL1 deregulated expression is common in childhood T-ALL, and is found in ~17% childhood cases.14 It results from the translocation, t(1;14)(p32;q11), in which TAL1 is translocated into TRA/D@,15 or more frequently a submicroscopic interstitial deletion of part of SIL and the 5’ untranslated region (UTR) of TAL1 generating the SIL-TAL1 fusion gene16,17 It was shown that both the t(1;14) translocation and TAL1 deletions disrupt the 5' part of the TAL1 gene, placing its entire coding sequence under the control of the regulatory elements of TRD@ or SIL, both of which are normally expressed in T-cell development.17,18 High expression levels of TAL1 in the absence of detectable rearrangements have been described in about 40% of T-ALL.8,19 TAL2 is upregulated in T-ALL as a result of the translocation, t(7;9)(q34;q32), which juxtaposes TAL2 and [email protected] LYL1 is the partner gene of TRB@ in the translocation, t(7;19)(q34;p13).21 It is also constitutively overexpressed in a subset of T-ALL in the absence of chromosomal rearrangements.22 T-ALL with LYL1 overexpression shows an immature phenotype and is associated with a poor prognosis. bHLHB1 is upregulated in T-ALL by the translocation, t(14;21)(q11,2;q22), which juxtaposes bHLHB1 and [email protected] In T-ALL with the translocations, t(7;12)(q34;p13.3) and t(12;14)(p13;q11), massive upregulation of CCND2 is produced by translocation to TRB@ and TRA@, respectively. This expression is associated with overexpression of TAL1, TLX1, TLX3, NOTCH1 mutations and CDKN2A deletions indicating a role for CCND2 in the multistep leukemogenesis of T-ALL.24 The MYC gene is well known for its upregulation by the IGH promoter in Burkitt’s lymphoma and mature B-cell ALL. In T-ALL, upregulation is brought about by the juxtaposition of MYC to TRA@ or TRB@ promoters. The LIM-domain-only genes, LMO1 and LMO2, are located at 11p15 and 11p13 respectively. They are frequently rearranged in T-ALL.25 The most common translocations are t(11;14)(p15;q11) and t(11;14) (p13;q11), juxtaposing LMO1 and LMO2 to the Figure 1. Break apart probe for TLX3 showing the split red and green signals on chromosomes 5 and 14, respectively. A fused red/green signal is present on the normal chromosome 5. LYL1 NOTCH1 TLX1 TAL2 TRB@ LMO1 LCK CDK6 MYC TLX3 CCND2 TRA/D@ HOXA@ LMO2 2p21 IGH@ bHLHB1 TAL1 Single Case BCL11B Recurrent (n=2-9) Recurrent (n=>10) Figure 2. Interrelationships between TCR loci, BCL11B and relevant oncogenes. TRA/D@ locus respectively.26,27 Translocations with TRB@ have also been reported.7 Cryptic deletions of the short arm of chromosome 11, del(11)(p12p13), have been identified in ~4% paediatric T-ALL by array based comparative genomic hybridization (aCGH).28 The deletion activates the LMO2 oncogene in the same way as the translocation which together Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 155 | 12th Congress of the European Hematology Association Table 1. The recurrent chromosomal abnormalities and molecular changes as defined within four pathways. HOXA@ TLX1* TLX3 PICALM-MLLT10* MLL 2. Proliferation and survival BCR-ABL1 NUP214-ABL1 ETV6-ABL1 EML1-ABL1 ETV6-JAK2 LCK FLT3 N-RAS t(9;22)(234;q11) t(9;9)(q34;q34)** t(9;12)(p24;p13) t(9;14)(q34;q32) t(9;12)(p24;p13) t(1;7)(p34;q34) mutations mutations 3. Cell cycle defects CDKN2A/CDKN2B del(9)(p21) 4. Self-renewal capacity NOTCH1 mutations t(7;9)(q34;q34.3) T T T B T T B T CDK6 ? F F F F F F F T F *Upregulated expression in the absence of visible abnormalities; v, various; **episomal or HSR; T, translocations involving TCR; B, translocation involving BCL11B; F, translocations (arising from) gene fusions; CDK6, upregulated by CDK6 promoter; ?, involved gene unknown account for about 9% of pediatric T-ALL. Overall, abnormal expression of LMO1 and LMO2 occurs in 45% of T-ALL including cases with no evidence of chromosomal changes.22,29 Their deregulation often occurs in association with deregulation of LYL1 (LMO2) or TAL1 (LMO1 and LMO2) confirming their involvement within common oncogeneic pathways. Homeobox (HOX) genes are key regulators in embryonic development and normal hematopoiesis. They are divided into two classes. Class 1 HOX genes BCL11B IGH@ 3’ TRG@ HOXA@ 3’ TRA/D@ 3’ TRG@ HOXA@ 3’ TRA/D@ 3’ BCL11B 5’ BCL11B 3’ BCL11B IGH@ der(14) LMO2* 5’ TRA/D@ 5’ TRG@ TRA/D@ Normal 14 LMO1* T F T T T T T T T T T T T B IGH@ 5’ BCL11B der(7) MYC t(1;14)(p32;q11) del(1)(p32) t(7;9)(q34;q32) t(7;19)(q34;p13) t(14;21)(q11;q22) t(7;12)(q34p13.3) t(12;14)(p13;q11) t(8;14)(q24;q11) t(7;8)(q34;q24) t(11;14)(p15;q11) t(7;11)(q34;p15) t(11;14)(p13;q32) t(7;11)(q34;p13) t(11;14)(p13;q32) del(11)(p13p13) inv(7)(p15q34) t(7;7)(p15;q34) t(7;14)(p15;q32) t(7;14)(p15;q32) t(10;14)(q24;q11) t(7;10)(q34;q24) t(5;14)(q35;q32) t(5;14)(q35;q11) t(5;7)(q35;q21) t(2;5)(p21;q35) t(10;11)(p13;q14) t(11;v)(q23;v) Normal 7 1. Differentiation impairment TAL1* SIL-TAL1 TAL2* LYL1* bHLHB1 CCND2 HOXA@ TRG@ Figure 3. Idiogram showing the position of probes specific for TCR, BCL11B, IGH@ and HOXA@ loci in a complex rearrangement involving TRA/D@, TRG@, BCL11B and HOXA@. comprise 39 genes distributed in four clusters (A-D) located to 7p15, 17q21, 12q13, and 2q31 respectively. In T-ALL, HOXA10 and HOXA11 are upregulated as a consequence of an often cryptic inversion of chromosome 7, inv(7) (p15q34) or the translocation, t(7;7)(p15;q34), which brings the TRB@ enhancer within the HOXA@ locus.31,32 HOXA is also upregulated by TRD@33 and BCL11B, specifically HOXA13.34 HOXA@ rearrangements are found in up to 3% of TALL by FISH.35 Rare reports of HOXA@ involved in complex rearrangements with TCR genes35 (Figure 3) indicate an additional mechanism of transcriptional activation of HOXA@ cluster genes, overexpression with gene dosage. Expression studies have identified a subgroup of HOXA@ expressing T-ALL32 which include, as well as cases with TCR-HOXA@, MLL,36 PICALM-MLLT10,37 cases without these rearrangements. This suggests the presence of additional as yet undisclosed mechanisms of HOX activation. The genes TLX1 and TLX3 belong to the class II homeobox genes. TLX1 is not normally expressed in developing T-cells although its oncogeneic potential is well known. It is located at 10q24 and is involved in the translocations, t(10;14)(q24;q11) and t(7;10) (q34;q24).38;39 As a result of juxtaposition of promoter elements of TRA@ and TRB@ respectively, the full length protein is expressed at a high level. TLX1 is also frequently activated in T-ALL in the absence of visible genetic rearrangement.8,22,40 TLX1 is expressed in ~30% T-ALL, more often in adults than children. These leukemias show an early cortical phenotype and a more favourable outcome than other classes of T-ALL.41 In the majority of cases, expression of TLX3 in TALL results, from the cryptic translocation t(5;14) | 156 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 A B Figure 4. A. Extrachromosomal amplification of the ABL1 signals (red) on episomes. B. Co-localization of 3’ ABL1 (red) and NUP214 signals (green) on episomes. (q35;q32), juxtaposing TLX3 to the distal region of BCL11B.42 This translocation is found in ~20% childhood and 13% adult T-ALL.43 Rare variants have been reported, as well as subtle genomic deletions and insertions within 5q.43,44 The latter abnormalities highlight that TLX3 expression in T-ALL rarely occurs in the absence of 5q abnormalities. The occasional findings of a t(5;14)(q35;q11) juxtaposing TLX3 and TRA/D@,45 a t(5;7)(q35;q21), a t(2;5)(p21;q35) involving TLX3 with CDK6 and an as yet uncharacterized locus on 2p21, respectively,43 indicate that the regulatory elements of TCR, along with other genes, may contribute to the upregulation of TLX3. Although their expression is mutually exclusive, gene expression studies have shown that T-ALL expressing either TLX3 or TLX1 cluster together, suggesting a common mechanism of action.22 TLX3 expressing T-ALL do not have the favourable outcome associated with TLX1 expression.14,22,46 The PICALM-MLLT10 fusion of the t(10;11) (p13;q14) is found in approximately 10% childhood and adult T-ALL and is associated with a poor prognosis.47-49 The fusion may occur in a cryptic rearrangement, as expression has been shown in the absence of the translocation. Expression arrays showed associated upregulation of HOXA5, HOXA9, and HOXA10 and their coregulator MEIS137 in these patients. The MLL gene at 11q23 is known to rearrange with more than 50 partners in translocations encoding chimeric proteins in which the N-terminal portion of MLL is fused to the C-terminal portion of the new partner.50 MLL fusions are rare in T-ALL, accounting for about 5%.51,52 The most frequent partners in TALL are MLLT1 (ENL) in the t(11;19) (q23;p13.3) and MLLT4 in the t(6;11) (q27;q23).51 Gene expression profiling demonstrated increased expression of the HOX@ gene: HOXA9, HOXA10, HOXC6, as well as MEIS1, to be a central mechanism of leukemic transformation in MLL positive T-ALL.36 This strongly indicates common oncogeneic pathways in PICALMMLLT10 and MLL T-ALL. Mutations providing a proliferative and survival advantage ABL1 is a ubiquitously expressed cytoplasmic tyrosine kinase, encoded by the ABL1 gene at 9q34. Although the BCR-ABL1 fusion of chronic myeloid leukemia and B-lineage ALL is exceptionally rare in T-ALL1 an alternative ABL1 fusion with NUP214 has recently been described as a secondary abnormality in 6% of T-ALL53 and 4% of adult patients.54 This was initially discovered by FISH screening for evidence of the BCR-ABL1 fusion which revealed multiple extrachromosomal ABL1 signals on episomes53,55 and, rarely, homogeneously staining regions (HSR).56 Cohybridisation of 3’ ABL1 and NUP214 signals confirmed the presence of both genes in the same episomes (Figure 4). An in-frame fusion between introns 23 to 34 of NUP214 and intron 1 of ABL1 was confirmed in patients with this abnormality. The results were compatible with a model in which the genomic region from ABL1 to NUP214 was circularized to provide the NUP214-ABL1 fusion. The copy number of the episome is increased due to unequal segregation during cell division. The NUP214-ABL1 fusion is associated with increased HOX@ expression22 and deletion of CDKN2A,57 consistent with a multistep pathogenesis of T-ALL. Like BCR-ABL1, NUP214ABL1 acts as a constitutively phosphorylated tyrosine kinase, which is also sensitive to imatinib, a selective inhibitor of ABL1 kinase activity. However, in a recently published case, the NUP214-ABL1 positive patient showed no response to imatinib.58 Other rare ABL1 fusions have been reported in TALL: ETV6-ABL1 of t(9;12)(q34;p13),59 the cryptic t(9;14)(q34;q32) encoding the EML1-ABL1 fusion protein.60 The latter case also had a deletion of CDKN2A and expression of TLX1 consistent with a multistep pathogenesis of T-ALL. The JAK2 gene is essential for transmission of signals from cytokine receptor to downstream signaling. In one case of pediatric T-ALL, a t(9;12) (p24;p13),61 encoding the ETV6-JAK2 fusion protein, was shown to result in constitutive tyrosine kinase activity. Its transforming role was demonstrated in mice.62 LCK is a tyrosine kinase gene specifically expressed in T cells. It is overexpressed in rare cases with t(1;7)(p34;q34), joining LCK to the TRB@ locus.63 FLT3 is a receptor tyrosine kinase. Activating mutations, such as internal tandem duplication (ITD) in the juxtamembrane domain or point mutations in the activation loop of the kinase domain are common in AML but rare in T-ALL. They are restricted to cases with a very immature phenotype expressing LYL1, LMO2 and the KIT receptor.64 Activating mutations of N-RAS have been detected in 10% of pediatric T-ALL.65 It is highly activated in 50% T-ALL66 suggesting a key role in T-ALL pathogenesis. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 157 | 12th Congress of the European Hematology Association Mutations affecting the cell cycle The CDKN2A and CDKN2B loci at 9p21 contain genes coding for p16INK4A, p14ARF and p15INK4B respectively, all involved in cell cycle regulation.67,68 Deletion of CDKN2A, often with CDKN2B, is the most frequent abnormality in T-ALL.57,69 Deletions may be homozygous or heterozygous seen in 65% and 15% of cases respectively. This abnormality usually occurs as a secondary change and is associated with all other primary genetic abnormalities in TALL.13 Inactivation of these loci may also arise from promoter hypermethylation or mutation at both the transcriptional and post transcriptional levels.70,71 The functional inactivation of CDKN2A in the majority of T-ALL implies a direct involvement in T-cell leukemogenesis72 through the RB1 and TP53 pathways.5 Mutations providing self renewal capacity NOTCH1 is a direct regulator of cell growth, playing a critical role in T-cell development.73 MYC is an important target of NOTCH1 in T-ALL and also in normal pre-T cell development.74 In T-ALL, NOTCH1 forms a fusion with TRB@ in the rare translocation t(7;9)(q34;q34.3). This results in aberrant expression of a truncated activated form of NOTCH1.75 Altogether, NOTCH1 activating mutations are found in more than 50% T-ALL, occurring most frequently in the heterodimerization (HD) and PEST domains, and are associated with short survival in adults but not children.76-78 NOTCH1 acts cooperatively with oncogene transcription factors in T-ALL pathogenesis.79 As NOTCH1 needs a gamma secretase enzyme for activation, there are ongoing trials on inhibitors of gamma secretase for treatment of aberrant NOTCH1 T-ALL. Molecular classification Interlaced with the four major classes of mutations involved in the molecular classification of T-ALL, as described by De Keersmaecker et al.,5 is the molecular classification which has emerged from gene expression profiling.4,22 That the relative expression of genes is of fundamental importance in T-ALL leukemogenesis comes from the observations that many of the significant transcription factors are aberrantly expressed in a large proportion of T-ALL in the absence of chromosomal abnormalities affecting the locus. Expression profiling of T-ALL has identified several gene expression signatures indicative of arrest at specific stages of thymocyte development: a LYL1 positive signature represents immature thymocytes (pro-T), TLX1 positive represented early cortical thymocytes and TAL1 correlated with late cortical thymocytes. Thus gene expression profiling has improved our understanding of the biological heterogeneity of the disease while revealing clinically rele- vant subtypes. Five different multistep molecular pathways have been defined that involve the activation of different oncogenes that lead to T-ALL: 1) TLX1; 2) TLX3; 3) TAL1 plus LMO1 and/or LMO2; 4) LYL1 plus LMO2; 5) MLL-MLLT1. TLX1, TLX3 and TAL1 positive patients show high levels of MYC expression and share the loss of CDKN2A locus whereas LYL1 positive cases show high level expression of MYC-N. The MLL-MLLT1 group has low levels of MYC expression but high levels of HOXA9, HOXA10, HOXC6 and MEIS1.4 It is evident that the interrelationships between the different molecular aberrations in T-ALL define multistep pathogenesis of the disease which may currently be oversimplified. New abnormalities may be uncovered as intensive research in the genetics of TALL continues. However, to date, molecular analysis has shown its capacity to clarify significant pathways relevant to the future treatment of T-ALL. References 1. Pui CH, Relling MV, Downing JR. Acute lymphoblastic leukemia. N Engl J Med 2004;350:1535-48. 2. Bene MC, Castoldi G, Knapp W et al. Proposals for the immunological classification of acute leukemias. European Group for the Immunological Characterization of Leukemias (EGIL). Leukemia 1995;9:1783-6. 3. Graux C, Cools J, Michaux L, Vandenberghe P, Hagemeijer A. Cytogenetics and molecular genetics of T-cell acute lymphoblastic leukemia: from thymocyte to lymphoblast. Leukemia 2006;20:1496-510. 4. Ferrando AA, Look AT. Gene expression profiling in T-cell acute lymphoblastic leukemia. Semin Hematol 2003;40:27480. 5. De Keersmaecker K, Marynen P, Cools J. Genetic insights in the pathogenesis of T-cell acute lymphoblastic leukemia. Haematologica 2005;90:1116-27. 6. van der Burg M, Poulsen TS, Hunger SP et al. Split-signal FISH for detection of chromosome aberrations in acute lymphoblastic leukemia. Leukemia 2004;18:895-908. 7. Cauwelier B, Dastugue N, Cools J et al. Molecular cytogenetic study of 126 unselected T-ALL cases reveals high incidence of TCRbeta locus rearrangements and putative new T-cell oncogenes. Leukemia 2006;20:1238-44. 8. Ferrando AA, Herblot S, Palomero T et al. Biallelic transcriptional activation of oncogenic transcription factors in T-cell acute lymphoblastic leukemia. Blood 2004;103:1909-11. 9. Wakabayashi Y, Watanabe H, Inoue J et al. Bcl11b is required for differentiation and survival of alphabeta T lymphocytes. Nat Immunol 2003;4:533-9. 10. Su XY, la-Valle V, ndre-Schmutz I et al. HOX11L2/TLX3 is transcriptionally activated through T-cell regulatory elements downstream of BCL11B as a result of the t(5;14)(q35;q32). Blood 2006;108:4198-201. 11. Nagel S, Kaufmann M, Drexler HG, MacLeod RA. The cardiac homeobox gene NKX2-5 is deregulated by juxtaposition with BCL11B in pediatric T-ALL cell lines via a novel t(5;14)(q35.1;q32.2). Cancer Res 2003;63:5329-34. 12. Przybylski GK, Dik WA, Wanzeck J et al. Disruption of the BCL11B gene through inv(14)(q11.2q32.31) results in the expression of BCL11B-TRDC fusion transcripts and is associated with the absence of wild-type BCL11B transcripts in TALL. Leukemia 2005;19:201-8. 13. Harrison CJ, Barber KE, Broadfield ZJ et al. Cytogenetic Classification of T lineage acute lymphoblastic leukaemia: multiple partners of BCL11B and other novel rearrangements [abstract]. Blood 2006; 14. Cave H, Suciu S, Preudhomme C et al. Clinical significance of HOX11L2 expression linked to t(5;14)(q35;q32), of HOX11 expression, and of SIL-TAL fusion in childhood T-cell malignancies: results of EORTC studies 58881 and 58951. Blood | 158 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 2004;103:442-50. 15. Carroll AJ, Crist WM, Link MP et al. The t(1;14)(p34;q11) is nonrandom and restricted to T-cell acute lymhoblastic leukemia:A pediatric oncology group study. Blood 1990; 76:1220-4. 16. Brown L, Cheng JT, Chen Q et al. Site-specific recombination of the tal-1 gene is a common occurrence in human T cell leukemia. EMBO Journal 1990;9:3343-51. 17. Janssen JW, Ludwig WD, Sterry W, Bartram CR. SIL-TAL1 deletion in T-cell acute lymphoblastic leukemia. Leukemia 1993;7:1204-10. 18. Bernard O, Lecointe N, Jonveaux P et al. Two site-specific deletions and t(1;14) translocation restricted to human T-cell acute leukemias disrupt the 5' part of the tal-1 gene. Oncogene 1991;6:1477-88. 19. Bash RO, Hall S, Timmons CF et al. Does activation of the TAL1 gene occur in a majority of patients with T-cell acute lymphoblastic leukemia? A pediatric oncology group study. Blood 1995;86:666-6. 20. Xia Y, Brown L, Yang CY et al. TAL2, a helix-loop-helix gene activated by the (7;9)(q34;q32) translocation in human T-cell leukemia. Proceedings of the National Academy of Sciences of the United States of America 1991;88:11416-20. 21. Mellentin JD, Smith SD, Cleary ML. lyl-1, a novel gene altered by chromosomal translocation in T cell leukemia, codes for a protein with a helix-loop-helix DNA binding motif. Cell 1989;58:77-83. 22. Ferrando AA, Neuberg DS, Staunton J et al. Gene expression signatures define novel oncogenic pathways in T cell acute lymphoblastic leukemia. Cancer Cell 2002;1:75-87. 23. Wang J, Jani-Sait SN, Escalon EA et al. The t(14;21)(q11.2;q22) chromosomal translocation associated with T-cell acute lymphoblastic leukemia activates the BHLHB1 gene. Proc Natl Acad Sci USA 2000;97:3497-502. 24. Clappier E, Cuccuini W, Cayuela JM et al. Cyclin D2 dysregulation by chromosomal translocations to TCR loci in T-cell acute lymphoblastic leukemias. Leukemia 2006;20:82-6. 25. Rabbitts TH. LMO T-cell translocation oncogenes typify genes activated by chromosomal translocations that alter transcription and developmental processes. Genes Dev 1998;12:2651-7. 26. McGuire EA, Hockett RD, Pollock KM et al. The t(11;14)(p15;q11) in a T-cell acute lymphoblastic leukemia cell line activates multiple transcripts, including Ttg-1, a gene encoding a potential zinc finger protein. Mol Cell Biol 1989;9:2124-32. 27. Royer-Pokora B, Loos U, Ludwig WD. TTG-2, a new gene encoding a cysteine-rich protein with the LIM motif, is overexpressed in acute T-cell leukaemia with the t(11;14)(p13;q11). Oncogene 1991;6:1887-93. 28. van Vlierberghe P, van GM, Beverloo HB et al. The cryptic chromosomal deletion del(11)(p12p13) as a new activation mechanism of LMO2 in pediatric T-cell acute lymphoblastic leukemia. Blood 2006;108:3520-9. 29. Asnafi V, Beldjord K, Libura M et al. Age-related phenotypic and oncogenic differences in T-cell acute lymphoblastic leukemias may reflect thymic atrophy. Blood 2004;104:417380. 30. van Oostveen J, Bijl J, Raaphorst F, Walboomers J, Meijer C. The role of homeobox genes in normal hematopoiesis and hematological malignancies. Leukemia 1999;13:1675-90. 31. Speleman F, Cauwelier B, Dastugue N et al. A new recurrent inversion, inv(7)(p15q34), leads to transcriptional activation of HOXA10 and HOXA11 in a subset of T-cell acute lymphoblastic leukemias. Leukemia 2005;19:358-66. 32. Soulier J, Clappier E, Cayuela JM et al. HOXA genes are included in genetic and biologic networks defining human acute T-cell leukemia (T-ALL). Blood 2005;106:274-86. 33. Bergeron J, Clappier E, Cauwelier B et al. HOXA cluster deregulation in T-ALL associated with both a TCRD-HOXA and a CALM-AF10 chromosomal translocation. Leukemia 2006;20:1184-7. 34. Su X, Drabkin H, Clappier E et al. Transforming potential of the T-cell acute lymphoblastic leukemia-associated homeobox genes HOXA13, TLX1, and TLX3. Genes Chromosomes Cancer 2006;45:846-55. 35. Cauwelier B, Cave H, Gervais C et al. Clinical, cytogenetic and molecular characteristics of 14 T-ALL patients carrying the TCRbeta-HOXA rearrangement: a study of the Groupe Francophone de Cytogenetique Hematologique. Leukemia 2007;21:121-8. 36. Ferrando AA, Armstrong SA, Neuberg DS et al. Gene expression signatures in MLL-rearranged T-lineage and B-precursor acute leukemias: dominance of HOX dysregulation. Blood 2003;102:262-8. 37. Dik WA, Brahim W, Braun C et al. CALM-AF10+ T-ALL expression profiles are characterized by overexpression of HOXA and BMI1 oncogenes. Leukemia 2005;19:1948-57. 38. Kennedy MA, Gonzalez Sarmiento R, Kees UR et al. HOX11, a homeobox-containing T-cell oncogene on human chromosome 10q24. Proc Natl Acad SciUSA. 1991;88:8900-4. 39. Hatano M, Roberts CW, Minden M, Crist WM, Korsmeyer SJ. Deregulation of a homeobox gene, HOX11, by the t(10;14) in T cell leukemia. Science 1991;253:79-82. 40. Kees UR, Heerema NA, Kumar R et al. Expression of HOX11 in childhood T-lineage acute lymphoblastic leukaemia can occur in the absence of cytogenetic aberration at 10q24: a study from the Children's Cancer Group (CCG). Leukemia 2003;17:887-93. 41. Ferrando AA, Neuberg DS, Dodge RK et al. Prognostic importance of TLX1 (HOX11) oncogene expression in adults with Tcell acute lymphoblastic leukaemia. Lancet 2004;363:535-6. 42. Bernard OA, Busson-LeConiat M, Ballerini P et al. A new recurrent and specific cryptic translocation, t(5;14)(q35;q32), is associated with expression of the Hox11L2 gene in T acute lymphoblastic leukemia. Leukemia 2001;15:1495-504. 43. Berger R, Dastugue N, Busson M et al. t(5;14)/HOX11L2-positive T-cell acute lymphoblastic leukemia. A collaborative study of the Groupe Francais de Cytogenetique Hematologique (GFCH). Leukemia 2003;17:1851-7. 44. Su XY, Busson M, Della V, V et al. Various types of rearrangements target TLX3 locus in T-cell acute lymphoblastic leukemia. Genes Chromosomes.Cancer 2004;41:243-9. 45. Hansen-Hagge TE, Schafer M, Kiyoi H et al. Disruption of the RanBP17/Hox11L2 region by recombination with the TCRdelta locus in acute lymphoblastic leukemias with t(5;14)(q34;q11). Leukemia 2002;16:2205-12. 46. Ballerini P, Blaise A, Busson-Le Coniat M et al. HOX11L2 expression defines a clinical subtype of pediatric T-ALL associated with poor prognosis. Blood 2002;100:991-7. 47. Asnafi V, Radford-Weiss I, Dastugue N et al. CALM-AF10 is a common fusion transcript in T-ALL and is specific to the TCRgammadelta lineage. Blood 2003;102:1000-6. 48. Groupe Francais de Cytogenetique Hematologique (GFCH). t(10;11)(p13-14;q14-21): a new recurrent translocation in T-cell acute lymphoblastic leukemias. Groupe Francais de Cytogenetique Hematologique (GFCH). Genes Chromosomes Cancer 1991;3:411-5. 49. Dreyling MH, Schrader K, Fonatsch C et al. MLL and CALM are fused to AF10 in morphologically distinct subsets of acute leukemia with translocation t(10;11): both rearrangements are associated with a poor prognosis. Blood 1998;91:4662-7. 50. Meyer C, Schneider B, Jakob S et al. The MLL recombinome of acute leukemias. Leukemia 2006;20:777-84. 51. Hayette S, Tigaud I, Maguer-Satta V et al. Recurrent involvement of the MLL gene in adult T-lineage acute lymphoblastic leukemia. Blood 2002;99:4647-9. 52. Armstrong SA, Staunton JE, Silverman LB et al. MLL translocations specify a distinct gene expression profile that distinguishes a unique leukemia. Nat Genet 2002;30:41-7. 53. Graux C, Cools J, Melotte C et al. Fusion of NUP214 to ABL1 on amplified episomes in T-cell acute lymphoblastic leukemia. Nat Genet 2004;36:1084-9. 54. Burmeister T, Gokbuget N, Reinhardt R et al. NUP214-ABL1 in adult T-ALL: the GMALL study group experience. Blood 2006;108:3556-9. 55. Barber KE, Martineau M, Harewood L et al. Amplification of the ABL gene in T-cell acute lymphoblastic leukemia. Leukemia 2004;18:1153-6. 56. Ballerini P, Busson M, Fasola S et al. NUP214-ABL1 amplification in t(5;14)/HOX11L2-positive ALL present with several forms and may have a prognostic significance. Leukemia 2005;19:468-70. 57. Hebert J, Cayuela JM, Berkeley J, Sigaux F. Candidate tumorsuppressor genes MTS1 (p16INK4A) and MTS2 (p15INK4B) display frequent homozygous deletions in primary cells from T- but not from B-cell lineage acute lymphoblastic leukemias [see comments]. Blood 1994;84:4038-44. 58. Stergianou K, Fox C, Russell NH. Fusion of NUP214 to ABL1 on amplified episomes in T-ALL: implications for treatment. Leukemia 2005;19:1680-1. 59. Golub TR, Goga A, Barker GF et al. Oligomerization of the ABL tyrosine kinase by the Ets protein TEL in human leukemia. Mol & Cel Biol 1996;16:4107-16. 60. De Keersmaecker K, Graux C, Odero MD et al. Fusion of EML1 to ABL1 in T-cell acute lymphoblastic leukemia with cryptic t(9;14)(q34;q32). Blood 2005;105:4849-52. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 159 | 12th Congress of the European Hematology Association 61. Peeters P, Raynaud SD, Cools J et al. Fusion of TEL, the ETSvariant gene 6 (ETV6), to the receptor-associated kinase JAK2 as a result of t(9;12) in a lymphoid and t(9;15;12) in a myeloid leukemia. Blood 1997;90:2535-40. 62. Lacronique V, Boureux A, Valle VD et al. A TEL-JAK2 fusion protein with constitutive kinase activity in human leukemia. Science 1997;278:1309-12. 63. Burnett RC, Thirman MJ, Rowley JD, Diaz MO. Molecular analysis of the T-cell acute lymphoblastic leukemia- associated t(1;7)(p34;q34) that fuses LCK and TCRB. Blood 1994; 84:1232-6. 64. Paietta E, Ferrando AA, Neuberg D et al. Activating FLT3 mutations in CD117/KIT+ T-cell acute lymphoblastic leukemias. Blood 2004;104:558-60. 65. Yokota S, Nakao M, Horiike S et al. Mutational analysis of the N-ras gene in acute lymphoblastic leukemia: a study of 125 Japanese pediatric cases. Int J Hematol 1998;67:379-87. 66. von Lintig FC, Huvar I, Law P et al. Ras activation in normal white blood cells and childhood acute lymphoblastic leukemia. Clin.Cancer Res. 2000;6:1804-10. 67. Stone S, Jiang P, Dayananth P et al. Complex structure and regulation of the P16 (MTS1) locus. Cancer Res. 1995;55:2988-94. 68. Stone S, Dayananth P, Jiang P et al. Genomic structure, expression and mutational analysis of the P15 (MTS2) gene. Oncogene 1995;11:987-91. 69. Cayuela JM, Madani A, Sanhes L, Stern MH, Sigaux F. Multiple tumor-suppressor gene 1 inactivation is the most frequent genetic alteration in T-cell acute lymphoblastic leukemia. Blood 1996;87:2180-6. 70. Okamoto A, Demetrick DJ, Spillare EA et al. Mutations and altered expression of p16INK4 in human cancer. Proc Natl Acad Sci USA 1994;91:11045-9. 71. Garcia-Manero G, Jeha S, Daniel J et al. Aberrant DNA methylation in pediatric patients with acute lymphocytic leukemia. Cancer 2003;97:695-702. 72. Omura-Minamisawa M, Diccianni MB, Batova A et al. Universal inactivation of both p16 and p15 but not downstream components is an essential event in the pathogenesis of T-cell acute lymphoblastic leukemia. Clin Cancer Res 2000;6:1219-28. 73. Maillard I, Fang T, Pear WS. Regulation of lymphoid development, differentiation, and function by the Notch pathway. Annu Rev Immunol 2005;23:945-74. 74. Weng AP, Millholland JM, Yashiro-Ohtani Y et al. c-Myc is an important direct target of Notch1 in T-cell acute lymphoblastic leukemia/lymphoma. Genes Dev 2006;20:2096-109. 75. Ellisen LW, Bird J, West DC et al. TAN-1, the human homolog of the Drosophila notch gene, is broken by chromosomal translocations in T lymphoblastic neoplasms. Cell 1991; 66:649-61. 76. Mansour MR, Linch DC, Foroni L, Goldstone AH, Gale RE. High incidence of Notch-1 mutations in adult patients with Tcell acute lymphoblastic leukemia. Leukemia 2006;20:537-9. 77. Weng AP, Ferrando AA, Lee W et al. Activating mutations of NOTCH1 in human T cell acute lymphoblastic leukemia. Science 2004;306:269-71. 78. Lee SY, Kumano K, Masuda S et al. Mutations of the Notch1 gene in T-cell acute lymphoblastic leukemia: analysis in adults and children. Leukemia 2005;19:1841-3. 79. Zhu YM, Zhao WL, Fu JF et al. NOTCH1 mutations in T-cell acute lymphoblastic leukemia: prognostic significance and implication in multifactorial leukemogenesis. Clin Cancer Res 2006;12:3043-9. | 160 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Acute Lymphoblastic Leukemia Treatment of Philadelphia chromosome positive acute lymphoblastic leukemia O.G. Ottmann H. Pfeifer B. Wassmann Johann Wolfgang Goethe Universität, Frankfurt/Main, Germany Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:161-167 A B S T R A C T Introduction of imatinib-based therapy into front-line treatment of Ph+ALL has greatly improved the rates of complete remission and there is evidence of improved overall outcome in adult patients with Ph+ALL. Accordingly, Imatinib combined with chemotherapy is now becoming the gold standard for treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia. The optimal treatment combinations, particularly with respect to consolidation and maintenance therapy remain to be determined for different populations, and are likely to differ substantially between elderly patients and younger patients, in whom SCT in first CR is still widely considered an essential element of curative therapy. Overcoming or preventing acquired imatinib resistance remains the predominant therapeutic challenge; the introduction of several novel kinase inhibitors that are more potent inhibitors of the Abl-kinase and are active against a wide spectrum of BCR-ABL mutations conferring imatinib resistance is an important addition to our therapeutic armament. The lessons learned during the clinical development of imatinib will have to be applied to these compounds as well to facilitate further rapid advances in treatment of Ph+ALL. he Philadelphia (Ph) chromosome is the result of a reciprocal translocation between chromosomes 9 and 22 [t(9;22)] and is characterized at the molecular level by expression of the BCR-ABL fusion gene. It is the most frequent genetic aberration in adult acute lymphoblastic leukemia (ALL), being detectable in 30-40% of patients with B-precursor ALL.1,2 In particular, its incidence increases with age, so that leukemic cells from approximately 50% of ALL patients older than 60 years have the Ph chromosome and/or express BCR-ABL transcripts. The prognosis of Ph+ALL is extremely poor even in younger patients, even though the complete remission rates with dose-intensive induction chemotherapy (approximately 60-80%) are only moderately inferior to those achieved in Ph negative.1-5 Conventional chemotherapy regimens that have been effective in other precursor B-cell ALL cases are largely unable to cure patients with this disease. Median remission duration ranges from 916 months in patients treated only with chemotherapy but there are almost no longterm survivors. Allogeneic stem cell transplantation (SCT) is considered to be the treatment of choice in adult Ph+ALL, with probabilities of long-term survival ranging from 27% to 65% in patients undergoing SCT in first complete remission (CR1). However, even T after SCT in CR1, the probability of relapse is approximately 30%.6 The highly successful introduction of the first ABL-kinase inhibitor imatinib into the treatment of Philadelphia chromosome positive chronic myeloid leukemia (CML) has led to clinical testing of imatinib in Ph+ALL. It has recently been approved for Ph+ALL in Europe and Japan. Given the much more aggressive nature of Ph+ALL when compared with chronic or even accelerated phase CML, a variety of imatinib-based treatment strategies have been explored in ALL. These studies will be the focus of this review. Induction therapy with single-agent imatinib The prognosis of elderly patients with acute lymphoblastic leukemia (ALL) is considerably inferior to that of younger patients, irrespective of cytogenetic aberrations. Chemotherapy induces complete remissions (CR) in approximately 50% of patients but responses are not sustained, with remission duration ranging from 3 to 12 months and a probability of long-term survival below 10%.7-10 Because of its high frequency in elderly patients, the Ph chromosome contributes significantly to the poor prognosis in this patient population, in addition to the greater frequency of comorbidity and reduced tolerability of cytotoxic drugs. Allogeneic SCT is not Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 161 | 12th Congress of the European Hematology Association appropriate applicable in elderly patients, as treatment-related mortality (TRM) increases substantially with age.6 Accordingly, monotherapy with an agent that selectively targets the leukemogenic BCR-ABL oncoprotein is an attractive option. The initial phase II studies of imatinib monotherapy in Ph+ALL were conducted in patients who had failed previous chemotherapy and, in some cases, also SCT;11-13 the overall response rate was 60-70%, with a CR rate of 17-30%. In addition, median time to progression was only 2.2 months, and median survival about 4.9 months.12,13 Together with the favorable toxicity profile of imatinib, these date led to the start several studies in which imatinib was used either alone or in conjunction with chemotherapy of varying intensities in elderly patients with newly diagnosed rather than advanced Ph+ALL. The efficacy of induction therapy with imatinib plus prednisone followed by maintenance treatment with imatinib alone was examined by the GIMEMA, as recently reported by Vignetti et al.14 Patient median age was 69 years, and all 29 patients evaluable for response achieved a CR within the first 45 days of treatment. However, only one patient had a complete molecular response as defined by undetectable BCR-ABL transcripts. Treatment was well tolerated with no deaths in CR. Relapse during imatinib maintenance was frequent, with a median remission duration of 8 months and an approximately 40% relapse rate within the first 4-6 months of treatment. The first prospective, randomized trial comparing the efficacy and tolerability of imatinib monotherapy with age-adapted multi-agent chemotherapy as induction treatment in de novo Ph+ALL was conducted by the German Multicenter Study Group for Adult ALL (GMALL). This study also examined the tolerability and outcome of subsequent uniform consolidation therapy in which all patients received imatinib concurrently with successive cycles of consolidation chemotherapy. Fifty-five patients with a median age of 68 years were enrolled.15 The overall CR rate was 96% in patients randomly assigned to imatinib induction and 50% in patients allocated to induction chemotherapy (p=0.0001). No patient failed imatinib induction whereas 35% of patients were refractory and 8% of patients died during induction chemotherapy. As expected, severe adverse events were significantly more frequent during front-line chemotherapy (90% vs. 39%; p=0.005). This initial benefit associated with imatinib induction was lost during the prolonged consolidation phase because of a substantial rate of death in CR that was attributable to cytotoxic chemotherapy. As a result, estimated overall survival (OS) was not significantly different between the two cohorts (42±8% at 24 months). The treatment strategy adopted by the GRAALL Study Group to assess the use of imatinib in previously untreated elderly patients was different in several respects.16 ALL patients aged 55 years or older were given steroids for the one week needed to establish the diagnosis of BCR-ABL positive ALL. Ph+ patients were then offered a chemotherapybased induction followed by a consolidation phase with imatinib and steroids lasting 2 months. Patients in CR after consolidation were given 10 maintenance blocks of alternating chemotherapy, including two additional 2-month blocks of imatinib. Therefore, this study used a more intensive maintenance therapy compared with the GIMEMA and GMALL studies.14,15 Thirty patients were included in this study and compared with 21 historic controls. Out of 29 assessable patients, 21 (72%) were in CR after induction chemotherapy vs 6/21 (29%) in controls (p=0.003). Five additional CR were obtained after salvage with imatinib and four after salvage with additional chemotherapy in the control group. Overall survival (OS) was 66% at 1 year vs 43% in the control group (p=0.005). The 1-year relapse-free survival was 58% vs 11% (p=0.0003).16 Therefore, the use of imatinib during the consolidation and maintenance phases in elderly patients with Ph+ ALL appears to improve outcome, including OS, but there was no apparent plateau on the Kaplan-Meier survival curves, mainly because of relapse. Combination therapy with imatinib and chemotherapy Several clinical trials conducted mainly in younger adult patients with newly diagnosed BCR-ABL-positive ALL assessed the efficacy and feasibility of different imatinib-chemotherapy combination regimens. In a prospective phase II study conducted by the Japan Adult Leukemia Study Group (JALSG), 80 patients with newly diagnosed BCR-ABL-positive ALL received imatinib in combination with induction therapy, followed by alternating cycles of imatnib and intensive consolidation chemotherapy.17 Remission induction therapy resulted in complete remission (CR) in 96% of patients, resistant disease was observed in one patient and early death in two patients. Polymerase chain reaction negativity for BCR-ABL transcripts in bone marrow samples was obtained in 71% of patients. The profile and incidence of severe toxicity were not different from those associated with the historic chemotherapyalone regimen. Twenty patients relapsed after a median CR duration of 5.2 months. Allogeneic hematopoietic stem-cell transplantation (HSCT) was performed in 49 patients, 39 of whom underwent transplantation during their first CR. The 1-year event-free and OS rates were estimated to be 60% | 162 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 and 76% respectively. These were significantly better than those for the historical control group treated with chemotherapy alone (p<.0001). Remarkably, the probability for OS at 1 year was not lower for those patients who underwent allogeneic HSCT (73%) as opposed to those who did not (85%). Therefore, their study not only shows that imatinibcombined regimen is effective and feasible for newly diagnosed BCR-ABL-positive ALL, but suggests that it may achieve outcome results comparable to allo SCT. The relatively short period of observation must however be taken into account. Encouraging survival data were also reported by Thomas et al. in a study combining imatinib with hyperCVAD chemotherapy. The CR rate was 96% in patients with active disease, and bcr-abl transcripts became undetectable by RT-PCR in 5 patients after hyperCVAD plus imatinib and in an additional 12 patients after allogeneic SCT.18 Parallel administration of imatinib with induction and consolidation chemotherapy was studied by the Spanish PETHEMA group, with a CR rate approaching 90%.19 Overall, these studies yielded no evidence of unexpected toxicities related to the addition of imatinib, and subsequent TBI-based stem cell transplantation did not appear to be adversely affected by preceding imatinib therapy. Two different schedules of imatinib-chemotherapy combinations were explored in sequential patients cohorts who were treated within a recent prospective multicenter GMALL trial including 92 patient with newly diagnosed Ph+ALL.20 While imatinib and chemotherapy were administered on an alternating schedule in the first cohort of patients, the second cohort received imatinib parallel to induction and early consolidation chemotherapy, and then without interruption until SCT. Coadministration of imatinib and induction cycle 2 (INDII) resulted in a CR rate of 95% and PCR negativity for BCR-ABL in 52% of patients, compared to 19% in patients in the alternating treatment cohort (p=0.01). This indicates greater antileukemic efficacy of a treatment strategy in which imatinib is started earlier and given parallel to chemotherapy. In the concurrent cohort, grade III/V cytopenias and transient hepatotoxicity required interruption of induction in 87% and 53% of patients respectively. However, duration of induction was not prolonged when compared to patients receiving chemotherapy alone. No imatinib-related severe hematologic or non-hematologic toxicities were noted with the alternating schedule. This confirmed the PETHEMA data19 showing that parallel administration does not significantly increase toxicity. Importantly, both schedules of imatinib help SCT in CR1 in the majority (77%) of patients, compared with just above 60% in a historic control group. The imatinib dosage most commonly used in the above studies ranged from 400 to 600 mg, partly because of concerns regarding toxicity when combined with intensive chemotherapy. A clinical trial evaluating a strategy based on high-dose imatinib (800 mg per day) combined with a less intensive chemotherapy regimen consisting of vincristine and dexamethasone (DIV induction regimen) enrolled 31 patients with Ph+ lymphoid leukemias (18 relapsing or refractory Ph+ ALL and 13 lymphoid blast crisis of CML).21 Complete remission was obtained in 28 out of 30 assessable patients, and the CR rate in patients older than 55 years was 90%. Median time to neutrophil recovery was 21 days. Six out of 31 patients developed fungal infections, possibly related to dexamethasone. Vincristine-induced neuropathy was noted in 14 patients, with no evidence of additional toxicity in older patients. Nine out of 19 patients below 55 years underwent allogeneic SCT. Given the favourable balance between efficacy and toxicity, the authors proposed investigating the use of this DIV regimen as front-line therapy in elderly patients. While the former studies initiated imatinib during induction and independent of the response to chemotherapy, the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAAPH) conducted a study in which imatinib was first administered after induction with HAM (mitoxantrone with intermediate-dose cytarabine) consolidation in good early responders (corticosensitive and chemosensitive ALL) or earlier during the induction course in combination with dexamethasone and vincristine in poor early responders (corticoresistant and/or chemoresistant ALL).22 Imatinib was then continuously administered until stem cell transplantation (SCT). Forty-five patients with newly diagnosed Ph+ ALL were treated, with overall CR and BCR-ABL real-time quantitative polymerase chain reaction (RQ-PCR) negativity rates of 96% and 29% respectively. All of the 22 CR patients (100%) with a donor actually received allogeneic SCT in first CR. At 18 months, the estimated cumulative incidence of relapse, disease-free survival, and overall survival were 30%, 51%, and 65% respectively, comparing favorably with results obtained in the pre-imatinib LALA-94 trial.4 Overall, the results obtained in this GRAAPH study are very consistent in tems of the overall response rate, and in confirming the value of a combined approach with imatinib and chemotherapy. Differences between the study results mostly relate to outcome, both in patients who underwent SCT and those who did not. This shows the need to evaluate the role of allogeneic SCT in the context of different pre-transplant regimens. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 163 | 12th Congress of the European Hematology Association Stem cell transplantation after front-line imatinib As described above, incorporation of imatinib into chemotherapy regimens prior to SCT appears to be a useful strategy for managing the time to allogeneic SCT and making SCT in CR1 easier for a great majority of Ph+ALL patients. Post-transplant outcome of 29 patients previously treated with an imatinibbased strategy was reported by Lee et al.23 At the time of enrollment, 23 patients (79%) had achieved a CR while 3 patients were refractory to both imatinib and chemotherapy. Relapse prior to SCT was significantly less frequent in the imatinib group than in the historic control (3.5% vs 42.3%, p=0.002). This allowed allogeneic SCT in first CR in 86% of the 29 patients, a significantly greater proportion than in the historic control group. With a median follow-up duration of 25 months after SCT, the 3-year estimated probabilities of relapse, non-relapse mortality and disease-free survival were 3.8%, 18.7% and 78.1% respectively. Acute transplant-related toxicity and mortality were not different in the two groups. These results indicate overall superior survival with pre-transplant imatinib therapy. The question whether imatinib therapy may compromise the outcome of subsequent SCT is very important in advanced Ph+ leukemias in which SCT offers the best option for cure. The effect of prior exposure to imatinib on transplant-related mortality was retrospectively analyzed by Deininger et al. in 21 patients with Ph+ ALL and 70 patients with CML who had received imatinib before SCT.24 At the time of SCT, 40% of ALL patients had active disease compared to 84% and 95% prior to imatinib, and 44% of CML patients were in accelerated phase or blast crisis. At 24 months, estimated transplant-related mortality was 44% and estimated relapse mortality 24%. No unusual organ toxicities were observed. Compared to historic controls, previous imatinib treatment did not influence overall survival, progression-free survival or non-relapse mortality, although there was a trend towards higher relapse mortality and significantly less chronic graft-versus-host disease. Overall, there was no evidence that imatinib negatively affects major outcomes after SCT, suggesting that imatinib before SCT is safe. Imatinib after stem cell transplantation Detection of minimal residual disease (MRD) after SCT is associated with a high probability of relapse. Starting Imatinib in the setting of MRD may lower this high relapse rate. In a prospective multicenter GMALL study, 27 Ph+ALL patients received Imatinib on detection of MRD after SCT. Bcr/abl transcripts became undetectable in 14 of 27 patients (52%), after a median of 1.5 months (earlyCRmol). All patients who achieved an earlyCRmol remained in remission for the duration of Imatinib treatment, 3 patients relapsed after Imatinib was discontinued. Failure to achieve PCR negativity soon after starting Imatinib predicted relapse. This occurred in 12 out of 13 patients (92%) after a median of 3 months. Disease-free survival (DFS) in earlyCRmol patients is 91±9% and 54±21% after 12 and 24 months respectively, compared with 8±7% after 12 months in patients remaining MRD-positive (p=0.0001).25 Therefore, approximately half of Ph+ALL patients who receive Imatinib for MRD positivity after SCT experience prolonged DFS which can be anticipated by the rapid achievement of a molecular CR. Continued detection of bcr/abl transcripts after 2-3 months on Imatinib identifies patients who will ultimately experience relapse and in whom additional or alternative antileukemic treatment should be started.26-27 Acquired resistance to imatinib Given the remarkably high CR rate achieved with imatinib-based therapy and its good tolerability in newly diagnosed Ph+ALL patients, acquired resistance to imatinib is the principal cause of treatment failure.28,29 Enhanced drug efflux, insufficient serum levels or BCR-ABL independence due to secondary transforming events are theoretical causes of drug failure that have not been confirmed in Ph+ALL. Pharmakokinetic resistance has been shown to cause the substantial rate of meningeal leukemia in patients with Ph+ALL receiving Imatinib without adequate CNS-directed prophylaxis, due to insufficient penetration of the blood brain barrier by imatinib.28 Prophylactic intrathecal CNS prophylaxis is therefore an essential element of any imatinib-based treatment strategy for Ph+ALL or CML-LBP. Mutations in the tyrosine kinase domain (TKD) of BCR-ABL have been the focus of studies on resistance and are found in the majority of Ph+ALL patients who relapse while on imatinib,33-37 Two recent reports addressing the frequency and distribution in patients with advanced or de novo Ph+ALL, demonstrated TKD mutations in up to 80% of patients with acquired resistance, with predominance of p-loop mutations known to confer high Numerous point mutations in the KD of BCR-ABL that impair imatinib binding to varying degrees have been identified as a major mechanism of acquired resistance in patients with chronic myeloid leukemia (CML).28,29 Data on BCR-ABL mutations in patients with Ph+ALL or lymphoid blast crisis of CML are more limited. Two studies of patients with advanced Ph+ lymphoid leukemias identified 5 different KD mutations in 14 of the 17 evaluted patients with acquired resistance to imatinib.31,32 Greater quantities of the E255K/V p-loop mutation, which occurred in 6 of 9 patients (67%) following their treatment with | 164 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 imatinib was suggested by one of these reports31 but not by the other.32 However, all point mutations arose at positions within the KD that are known to be important for drug binding and to give significant resistance to imatinib in vitro.33-35 This demonstrated that different mutations within the BCR-ABL KD can be responsible for refractoriness of Ph+ lymphoid leukemias to imatinib, and also suggested that KD mutations may be a frequent mechanism of, or contributory factor to, acquired imatinib resistance during salvage therapy with imatinib. Using denaturing high-performance liquid chromatography and sequencing, Soverini et al. screened for ABL kinase domain mutations in 370 patients with Ph+ lymphoid leukemias with hematologic or cytogenetic resistance to imatinib.38 Mutations were found in 83% of lymphoid blast crisis/Ph+ acute lymphoblastic leukemia (ALL) patients. P-loop and T315I mutations were particularly frequent in Ph+ ALL and advanced-phase CML patients. Amino acid substitutions at seven residues (M244V, G250E, Y253F/H, E255K/V, T315I, M351T, and F359V) accounted for 85% of all resistance-associated mutations.31,32 The very short median time to progression observed in patients with advanced Ph+ALL treated with imatinib in the early phase II studies suggested the possibility that KD mutations might already be present before imatinib therapy. While BCR-ABL KD mutations were not detected in patients with chemotherapy-resistant acute lymphoid leukemia before imatinib treatment when a direct sequencing approach was used,31,32 it was subsequently demonstrated that low-level KD mutations are present at least in a small proportion of imatinib-naïve Ph+ ALL.39 As the proportion of mutant alleles at the start of imatinib therapy were low, highly sensitive detection techniques are required to detect low-level mutant clones. Pfeifer et al. investigated the prevalence and distribution pattern of BCR-ABL TKD mutations in pretherapeutic leukemic samples and bone marrow samples collected throughout imatinib-based therapy from patients with newly diagnosed Ph+ ALL, and in leukemic samples from relapsed patients by means of highly sensitive denaturing HPLC (WAVE™) and allel-specific oligonucleotide PCR (ASO-PCR) and by cDNA sequencing.40 Remarkably, TKD mutations were detected in a minor subpopulation of leukemic cells in 40% of newly diagnosed and imatinib-naïve patients. At relapse, the dominant cell clone had an identical mutation in 90% of cases, the overall prevalence of mutations at relapse was 80%, with predominance of p-loop mutations. Thus, BCR-ABL mutations giving highlevel imatinib resistance are present in a substantial proportion of patients with de novo Ph+ ALL and eventually lead to relapse. This provides a rationale for the front-line use of kinase inhibitors active against these BCR-ABL mutants. Second generation ABL-kinase inhibitors Several novel ABL kinase inhibitors have recently entered the clinical testing phase.41,42 Nilotinib is a selective, aminopyrimidine which is 30 times more potent in vitro than imatinib and active against most tested imatinib resistant Bcr-Abl mutations. The safety and efficacy of nilotinib administered at a dose of 400 mg bid was evaluated in 34 patients with Ph+ALL who had relapsed after or were refractory to imatinib. Chromosomal abnormalities other than Ph+ were noted in 35% and extramedullary involvement in 9% of Ph+ALL patients. Complete responses were reported in 2 (6%) patients. The main reason for discontinuing nilotinib was disease progression. The most frequent Grade 3 or 4 adverse events occurring in patients with Ph+ALL were thrombocytopenia in 3 (9%) patients, and 2 (6%) patients each had neutropenia, blood bilirubin increased, ALT elevation and bone pain. These clinical phase II data therefore show clinical activity and an acceptable safety and tolerability profile in patients with imatinib resistant relapsed/refractory Ph+ALL, suggesting that trials in front-line treatment are warrented.43 Dasatinib is a novel, oral, multi-targeted kinase inhibitor of BCR-ABL and SRC. Its usefulness in the treatment of Ph+ALL was explored in an open label, multi-center, global phase-II study which included 46 relapsing patients with Ph+ALL. These patients had previously been treated with chemotherapy including imatinib, and 37% of them had received a stem cell transplant. The starting dose of dasatinib was 70 mg twice daily (BID). In the 40 patients with baseline mutation data, imatinib-resistant BCR-ABL mutations were observed in 78%, one with T315I. The overall complete hematologic response rate was 35%. The major hematologic response (MHR) in the 31 patients with baseline mutations was 45%. The median duration of MHR was 11 months and the median progression-free survival was 3.7 months. Grades 3 and 4 thrombocytopenia occurred in 13% and 67%, respectively and grades 3 and 4 neutropenia occurred in 27% and 52% of patients, respectively. Most frequent non-hematologic toxicities included diarrhea, nausea and pleural effusion. Overall, these data show significant clinical efficacy in this prognostically poor group of patients, but also emphasize the need to employ these second generation kinase inhibitor at earlier stages of Ph+ALL rather than as salvage therapy.44 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 165 | 12th Congress of the European Hematology Association Acknowledgments Supported by the Competence Network Acute and Chronic Leukemias, BMBF grant 01GI9971, the National Genome Research Network (NGFN) and the Adolf Messer Foundation. References 1. Radich JP. Philadelphia chromosome-positive acute lymphocytic leukemia. Hematol Oncol Clin North Am 2001;15:21-36. 2. Hoelzer D, Gökbuget N. Recent approaches in acute lymphoblastic leukemia in adults. Crit Rev Oncol Hematol 2000;36:49-58. 3. Gleißner B, Gökbuget N, Bartram CR, et al. Leading prognostic relevance of the BCR-ABL translocation in adult acute Blineage lymphoblastic leukemia: a prospective study of the German Multicenter Trial Group and confirmed polymerase chain reaction analysis. Blood 2002;99:1536-43. 4. Dombret H, Gabert J, Boiron JM, Rigal-Huguet F, Blaise D, Thomas X et al. Outcome of treatment in adults with Philadelphia chromosome-positive acute lymphoblastic leukemia-results of the prospective multicenter LALA-94 trial. Blood 2002;100:2357-66. 5. Kantarjian HM, O'Brien S, Smith TL, Cortes J, Giles FJ, Beran M, Pierce S, Huh Y, Andreeff M, Koller C, Ha CS, Keating MJ, Murphy S, Freireich EJ. Results of treatment with hyperCVAD, a dose-intensive regimen, in adult acute lymphocytic leukemia. J Clin Oncol 2000;18:547-61. 6. Martin TG, Gajewski JL. Allogeneic stem cell transplantation for acute lymphocytic leukemia in adults. Advances in the treatment of adult acute lymphocytic leukemia. Hematol Oncol Clin North Am 2001;15:97-120. 7. Brandeis JM, Gupta V, Wells RA, et al. Treatment of elderly patients with acute lymphoblastic leukemia-evidence for a benefit of imatinib in BCR-ABL positive patients. Leuk Res 2005;29:1381-6 8. Ferrari A, Annino L, Crescenzi S, et al. Acute lymphoblastic leukemia in the elderly: results of two different treatment approaches in 49 patients during a 25-year period. Leukemia 1995;9:1643-7. 9. Goekbuget N, de Wit, M, Gerhardt, A, et al. Results of a shortened, dose reduced treatment protocol in elderly patient with acute lymphoblastic leukaemia. Blood 2000;96:3104a [abstract]. 10. Annino L, Goekbuget N, Delannoy A. Acute lymphoblastic leukemia in the elderly. Hematol J 2002;3:219-23. 11. Druker BJ, Sawyers CL, Kantarjian H, et al. Activity of a specific inhibitor of the BCR-ABL tyrosine kinase in the blast crisis of chronic myeloid leukemia and acute lymphoblastic leukemia with the Philadelphia chromosome. N Engl J Med 2001;344:1038-42. 12. Ottmann OG, Druker BJ, Sawyers CL, Goldman JM, Reiffers J, Silver RT et al. A phase 2 study of imatinib in patients with relapsed or refractory Philadelphia chromosome-positive acute lymphoid leukemias. Blood 2002;100:1965-71. 13. Wassmann B, Pfeifer H, Scheuring UJ, Binckebanck A, Gökbuget N et al. Early prediction of response in patients with relapsed or refractory Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+ALL) treated with imatinib mesylate (Glivec). Blood 2004;103:1495-8. 14. Vignetti M, Fazi P, Cimino G, Martinelli G, Di Raimondo F, Ferrara F, et al. Imatinib plus steroids induces complete remissions and prolonged survival in elderly Philadelphia chromosome-positive acute lymphoblastic leukemia patients without additional chemotherapy: results of the GIMEMA LAL0201-B protocol. Blood 2007 Jan 9;[Epub ahead of print] 15. Ottmann OG, Wassmann B, Pfeifer H, Giagounidis A, Stelljes M, Dührsen U, et al. Imatinib compared with chemotherapy as front-line treatment of elderly patients with philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ALL). Cancer (in press). 16. Delannoy A, Delabesse E, Lheritier V, et al. Imatinib and methylprednisolone alternated with chemotherapy improve the outcome of elderly patients with Philadelphia-positive acute lymphoblastic leukemia: results of the GRAALL AFR09 study. Leukemia 2006;20:1526-32. 17. Yanada M, Takeuchi J, Sugiura I, et al. High complete remission rate and promising outcome by combination of imatinib and chemotherapy for newly diagnosed BCR-ABL-positive 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. acute lymphoblastic leukemia: a phase II study by the Japan Adult Leukemia Study Group. J Clin Oncol 2006;24:460-6. Thomas DA, Faderl S, Cortes J, et al. Treatment of Philadelphia chromosome-positive acute lymphocytic leukemia with hyper-CVAD and imatinib mesylate. Blood 2004; 103:4396-407. Ribera J-M, Oriol A, Gonzalez M, Vidriales M-B, Xicoy B et al. Treatment of Philadelphia Chromosome (Ph)-Positive Acute Lymphoblastic Leukemia (ALL) with Concurrent Chemotherapy and Imatinib Mesylate. Blood 2004;104: [abstr. 4483]. Wassmann B, Pfeifer H, Goekbuget N, et al. Alternating versus concurrent schedules of imatinib and chemotherapy as frontline therapy for Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). Blood 2006;108:1469-77. Rea D, Legros L, Raffoux E, Thomas X, Turlure P, Maury S, et al. Intergroupe Francais des Leucemies Myeloides Chronique; Group for Research in Adult Acute Lymphoblastic Leukemia. High-dose imatinib mesylate combined with vincristine and dexamethasone (DIV regimen) as induction therapy in patients with resistant Philadelphia-positive acute lymphoblastic leukemia and lymphoid blast crisis of chronic myeloid leukemia. Leukemia. 2006;20:400-3. de Labarthe A, Rousselot P, Huguet-Rigal F, Delabesse E, Witz F, Maury S, et al. Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL). Imatinib combined with induction or consolidation chemotherapy in patients with de novo Philadelphia chromosome-positive acute lymphoblastic leukemia: results of the GRAAPH-2003 study. Blood 2007 15;109:1408-13. Epub 2006 Oct 24. Lee KH, Lee JH, Choi SJ, et al. Clinical effect of imatinib added to intensive combination chemotherapy for newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia. Leukemia 2005;19:1509-16. Deininger M, Buchdunger E, Druker BJ. The development of imatinib as a therapeutic agent for chronic myeloid leukemia. Blood 2005;105:2640-53. Wassmann B, Pfeifer H, Stadler M, Bornhauser M, Bug G et al. Early molecular response to post-transplant imatinib determines outcome in MRD-positive Philadelphia-positive acute lymphoblastic leukemia (Ph+ALL) Blood First Edition Paper, prepublished online April 7,2005. Blood 2004;05:1746. Ottmann OG, Wassmann B, Pfeifer H, Goekbuget N, Bug G et al. Imatinib given concurrently with induction chemotherapy is superior to imatinib subsequent to induction and consolidation in newly diagnosed philadelphia-positive acute lymphoblastic leukemia (PH+ALL). Blood 2004;104: [abstr. 685] Lee S, Kim YJ, Min CK, Kim HJ, Eom KS, Kim DW, et al. The effect of first-line imatinib interim therapy on the outcome of allogeneic stem cell transplantation in adults with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia. Blood 2005;105:3449-57. Hofmann WK, Komor M, Hoelzer D, Ottmann OG. Mechanisms of resistance to STI571 (Imatinib) in Philadelphia-chromosome positive acute lymphoblastic leukemia. Leuk Lymphoma 2004; 45:655-60. von Bubnoff N, Peschel C, Duyster J. Resistance of Philadelphia-chromosome positive leukemia towards the kinase inhibitor imatinib (STI571, Glivec): a targeted oncoprotein strikes back. Leukemia 2003;17:829-38. Pfeifer H, Wassmann B, Hofmann WK, Komor M, Scheuring U et al. Risk and prognosis of central nervous system (CNS) leukemia in patients with philadelphia chromosome positive (Ph+) acute leukemias treated with imatinib mesylate (GlivecTM). Clin Cancer Res 2003;9:4674-81. Hofmann WK, Jones LC, Lemp NA, et al. Ph(+) acute lymphoblastic leukemia resistant to the tyrosine kinase inhibitor STI571 has a unique BCR-ABL gene mutation. Blood 2002;99:1860-2. von Bubnoff N, Schneller F, Peschel C, et al. BCR-ABL gene mutations in relation to clinical resistance of Philadelphiachromosome-positive leukaemia to STI571: a prospective study. Lancet 2002;359:487-91. Corbin AS, La Rosee P, Stoffregen EP, et al. Several Bcr-Abl kinase domain mutants associated with imatinib mesylate resistance remain sensitive to imatinib. Blood 2003;101:46114. Gorre ME, Mohammed M, Ellwood K, et al. Clinical resistance to STI-571 cancer therapy caused by BCR-ABL gene mutation or amplification. Science 2001;293:876-80. Shah NP, Nicoll JM, Nagar B,et al. Multiple BCR-ABL kinase domain mutations confer polyclonal resistance to the tyrosine kinase inhibitor imatinib (STI571) in chronic phase and blast crisis chronic myeloid leukemia. Cancer Cell 2002;2:117-25. | 166 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 36. Branford S, Rudzki Z, Walsh S, et al. High frequency of point mutations clustered within the adenosine triphosphate-binding region of BCR/ABL in patients with chronic myeloid leukemia or Ph-positive acute lymphoblastic leukemia who develop imatinib (STI571) resistance. Blood 2002;99:3472-5. 37. Hochhaus, A. Kreil S, Corbin AS, et al. Molecular and chromosomal mechanisms of resistance to imatinib (STI571) therapy. Leukemia 2002;16:2190-6. 38. Soverini S, Colarossi S, Gnani A, et al. Contribution of ABL Kinase domain mutations to imatinib resistance in different subsets of Philadelphia-positive patients. Clin Cancer Res 2006; 12:7374-9. 39. Hofmann WK, Komor M, Wassmann B, Jones LC, Gschaidmeier H, Hoelzer D, Koeffler HP, Ottmann OG. Presence of the BCR-ABL mutation Glu255Lys prior to STI571 (imatinib) treatment in patients with Ph+ acute lymphoblastic leukemia. Blood 2003;102:659-61. 40. Pfeifer H, Wassmann B, Pavlova A, Wunderle L, Oldenburg J, Binckebanck A, et al. Kinase domain mutations of BCR-ABL frequently precede imatinib-based therapy and give rise to relapse in patients with de novo Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). Blood 2007 Apr 3; [Epub ahead of print] 41. Kantarjian H, Giles F, Wunderle L, et al. Nilotinib in imatinibresistant CML and Philadelphia chromosome-positive ALL. N Engl J Med 2006;354:2542-51. 42. Talpaz M, Shah NP, Kantarjian H, et al. Dasatinib in imatinibresistant Philadelphia chromosome-positive leukemias. N Engl J Med 2006;354:2531-41. 43. Ottmann O, Kantarjian H, Larson R, le Courte P, Baccarani M, Rafferty T, et al. A Phase II study of nilotinib, a novel tyrosine kinase inhibitor administered to imatinib resistant or intolerant patients with chronic myelogenous leukemia (CML) in blast crisis (BC) or relapsed/refractory Ph+ acute lymphoblastic leukemia (ALL). Blood (ASH Annual Meeting Abstracts) 2006;108:1862. 44. Dombret H, Ottmann OG, Rosti G, Simonsson B, Larson RA, Gollerkeri A, et al. Dasatinib (SPRYCEL®) in patients (pts) with philadelphia chromosome-positive acute lymphoblastic leukemia who are imatinib-resistant (im-r) or -intolerant (imi): updated results from the CA180-015 ‘START-L’ Study. Blood (ASH Annual Meeting Abstracts) 2006;108:286. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 167 | Acute Lymphoblastic Leukemia Detection of minimal residual disease in adult patients with acute lymphoblastic leukemia: methodological advances and clinical significance M. Brüggemann T. Raff S. Böttcher S. Irmer S. Lüschen C. Pott M. Ritgen N. Gökbuget D. Hoelzer M. Kneba Universitätsklinikum, Schleswig-Holstein, Kiel, Germany Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:168-174 lthough 80%-95% of adult patients with acute lymphoblastic leukemia (ALL) achieve complete clinical remission with current treatment protocols,1-4 the majority of them ultimately relapse. Relapses are caused by residual malignant cells that are undetectable by standard diagnostic techniques.5 With the development of more sensitive techniques for the detection of malignant cells, the presence of minimal residual disease (MRD) in patients in complete clinical remission has clearly been demonstrated. It is important to determine whether such sensitive MRD detection has clinical significance.6-13 Therefore, different techniques for sensitive and specific MRD quantification have been established in the past 15 years. A MRD techniques Each approach is characterized by advantages and limitations, mainly related to its sensitivity and specificity (see Table 1, reviewed in5,14-18), which should be taken into account when large scale multicenter clinical MRD studies are planned. Immunological analysis Flow cytometry represents a rapid and reliable option for investigating MRD in the vast majority of ALL patients. The characteristic immunophenotype of residual ALL cells is identified via multi-colour flow cytometry. The main problem is the discrimination of malignant cells from normal lymphoid precursors resembling ALL cells. In T-ALL, discrimination is facilitated by the fact that early T-cell development takes place in the thymus and therefore detection of (TdT+ and/or CD34+) T-precursors in the bone marrow or blood signifies the presence of T-ALL cells.15 By contrast, in precursor-B-ALL the sensitive distinction of residual ALL from normal precursor-B-cells is not easy, particularly in regenerating bone marrow during or after therapy when benign B-precursors can account for up to 5% of all leucocytes.19 The unambiguous | 168 | identification is based on aberrant immunophenotypes with qualitative (e.g. expression of CD66c, CD13, CD33, NG-2, CD21) or quantitative (e.g. underexpression of CD10, CD38, CD45 and overexpresssion of CD58) differences in expression patterns compared to benign B-precursors.15,20-23 Using 4-colour flow cytometry, leukemia-associated immunophenotypes can be identified in about 90% of B-precursor and more than 95% of all T-ALL patients24 reaching a detection limit of 10–3 to 10–4.9,22,25-27 However, immunophenotypic shifts occur;20,28 therefore preferably two different aberrant immunophenotypes should be monitored to prevent false negativity. New immunophenotypic tools like 6- to 8-colour flow cytometry, new fluorochromes, improved analysis facilities, and characterisation of additional leukemia-associated antigens will improve sensitivity and specificity of this method.22,29 Recently, EuroFlow, a European network of Flow laboratories started to develop standardized ≥6-colour flow cytometric strategies for fast, accurate and sensitive quantification of low level MRD. PCR analysis of clonal immunereceptor gene rearrangements During early T- and B-cell development immunoglobulin (Ig) and T-cell receptor (TCR) genes rearrange and form fingerprint-like sequences at their junctional regions. As the different subtypes of ALL represent clonal expansions of the malignant counterpart of early lymphoid development, almost all ALLs harbour clonal Ig and/or TCR gene rearrangements allowing for DNA based MRD quantification in more than 90% of all ALL patients. Clonal Ig rearrangements can be identified in >95% of all precursor B-ALL but also in about 10% to 15% of T-ALL. The large majority of T-ALL display clonally rearranged TCR genes which also occur as cross-lineage rearrangements in about 90% of precursor B-ALL.16,30-35 Clonality can be assessed using primers annealing to Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 conserved regions of the V-, D- and J-segments of the different immunereceptor genes. With the use of fluorescent dye labeled primers PCR-products can be easily detected by automated fluorescence fragment analysis (GeneScanning) with a size-discrimination down to 1 basepair. By this consensus primer – PCR approach a clonal rearrangement can be detected with a sensitivity of one single tumour cell in the background of 20 to 1,000 polyclonal lymphoid cells.36-38 To obtain a higher level of sensitivity, DNA sequencing of the junctional regions is required in order to design tumour-specific primers and probes. Thanks to the development of real-time quantitative (RQ)-PCR techniques, precise quantification is possible during the early exponential phase of PCR amplification. This technology eliminates variations during late post-exponential phases of PCR reaction and during post-PCR manipulation of samples. A major problem when using rearranged immunereceptor genes as MRD-PCR targets is the possibility of oligoclonality and continued rearranging during the course of therapy and during follow-up that can lead to false negative PCR results.30,39-41 Therefore two immunereceptor gene PCR targets should usually be used for Ig/TCR based MRD analyses. Several RQ-PCR approaches have been developed for almost all Ig/TCR gene rearrangements.17,42-47 Standardization of analysis and data interpretation are the subject of the European Study Group on MRD detection in ALL (ESG) made up of 32 experienced PCR laboratories spread over Europe, Israel, Singapore, and Australia.48 Currently, most ALL trials that implement MRD analysis apply Ig/TCR based assays since for the moment these represent the most standardized and sensitive techniques. PCR analysis of chromosomal translocations Structural chromosomal aberrations that lead to characteristic fusion genes are ideal PCR targets because they are highly specific and can reach excellent sensitivities of 10–4 to 10–6.49 In ALL most assays analyze specific fusion gene transcripts via reverse transcriptase (RT)-PCR analysis, but some chromosome aberrations are also detected on DNA level.50,51 These targets allow a rapid and relatively cheap MRD quantification because the same set of reagents can be used for different patients. The disadvantages are the possibility of false positivity due to cross-contamination which is difficult to recognize, since leukemia-specific fusion gene RT-PCR products are not patient-specific. Also, RNA is rather unstable and different stability of fusion gene transcripts and control gene transcripts may result in unreliable MRD quantification.52 The main problem is that only about 30-40% of precursor B-ALL (BCR-ABL, E2A-PBX1, MLL-AF4, TEL-AML1) and about 10-20% of T-ALL (particularly SIL-TAL1, CALM-AF10) patients have specific PCR detectable chromosome aberrations.16 Standardized approaches have been developed particularly for the quantification of BCR-ABL fusion gene transcripts in Philadelphia chromosome positive (Ph+) ALL.53,54 MRD quantification in this ALL subgroup is important not only after stem cell transplantation but also for monitoring treatment with tyrosine kinase inhibitors. Although similar MRD results can be obtained by flow cytometry and PCR analysis, MRD levels and sensitivity may differ in a significant proportion of cases, emphasizing that these techniques are not simply exchangeable.26,55-58 Table 1. Characteristics of MRD techniques in acute lymphoblastic leukemia.16,18 Applicability PrecursorB-ALL T-ALL Immunophenotyping 80-95% >95% PCR analysis of chromosomal translocations 30-40% 10-20% PCR analysis of clonal Ig/TCR gene rearrangements >90% ~95% Advantages Disadvantages fast quantitative with information on benign cells cell viability can be determined immunophenotypic shift background of benign cells limited sensitivity using 3- to 4-colour flow cytometry fast high sensitivity (10-4-10-6) stable targets relatively cheap cross-contamination of PCR products instability of RNA differences in expression levels possible applicable only for a minority of patients high sensitivity (10-4 -10-5) stability of DNA applicable for almost all ALL patients time consuming relatively expensive loss of markers due to clonal evolution Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 169 | 12th Congress of the European Hematology Association Clinical significance of MRD in ALL Prognostic value of MRD in adult ALL Several large-scale studies in childhood ALL have demonstrated that MRD analysis by molecular or highly sensitive immunological methods can predict clinical outcome and that this MRD information is independent of classic prognostic factors at diagnosis such as age, sex, white blood cell count, immunophenotype and chromosome aberrations.6-13 Results of MRD evaluation in adult ALL generally confirmed the findings obtained in paediatric ALL.59-63 However, frequency of MRD positivity tends to be higher in adult disease, probably reflecting the higher in vivo drug resistance. Comparable to the result of paediatric trials, high level MRD after induction treatment is associated with a high risk of relapse in adult ALL. In the GMALL MRD study on 196 standard-risk ALL patients, MRD levels ≥10–4 after start of consolidation treatment was detected in about 25% of cases and was associated with an extremely poor prognosis (3year disease-free survival (DFS) 12%)59 (Figure 1). This agrees with findings of Mortuza and colleagues60 who investigated 85 adult patients with Blineage ALL. DFS for patients with detectable MRD 3-5 months and 6-9 months after diagnosis, was 11% and 0% respectively, compared to 74% and 80% in MRD-negative patients. Similarly, Brisco et al.64 analyzed MRD in 27 adults using PCR techniques. Eight out of 11 patients (73%) with MRD >10–3 relapsed compared to 6/16 (38%) with MRD <10–3 after the end of induction (day +22 to +68). In an immunophenotypic study on 102 adolescent and adult ALL patients Vidriales and colleagues62 demonstrated the high predictive value of day +35 MRD. However relapse rate was about 50%, even in patients with MRD levels <0.05%. Therefore, MRD after induction in adult ALL has a high discriminative value. But also patients with low or undetectable MRD at this timepoint show considerable relapse rates.59,62,64 In contrast, early MRD quantification during induction (day +11 or day +14) identifies patients with a very rapid molecular response and an excellent prognosis (3year DFS 90-92%), in line with reports on childhood ALL. Therefore, the same MRD status achieved after a different period of time results in different prognoses. The combined information on MRD kinetics identifies those patients with a rapid tumour clearance and a favourable outcome from those with persistent disease and a particularly high relapse rate. Few MRD studies focussed on T-ALL patients65,66 who account for about 20% of adult ALL cases. Immunophenotypic data suggest the relapse-predicting value of MRD also for this patient group.66 MRD positivity before consolidation (MRD+: 38% of patients), before the third reinduction (MRD+: 34%), and before reinduction cycle 6 (MRD+: 17%) was associated with a 2-year relapse rates of 81.5%, 54.5% and 50.0% respectively, while MRD negativity at those time-points predicted a more favorable outcome (relapse rate 38.9%, 15.8% and 16.4%).66 By contrast, preliminary PCR data of the UKALL study group did not provide conclusive results and, in particular, failed to predict outcome on the basis of discrete testing time-points,65 whereas MRD was highly predictive in B-cell precursor ALL.60 Within the GMALL trial, percentages of MRD positivity and prognostic impact did not significantly differ in patients with T-lineage ALL compared with B-lineage ALL.59 However, only standard risk patients, and therefore only the immunophenotypic subgroups of cortical T-ALL, pre-B and c-ALL, were investigated. Systematic and prospective analyses on differences in MRD kinetics depending on immunophenotypes have still not been carried out for adult ALL. In Ph+ ALL, RT-PCR analysis of BCR-ABL fusion transcript is a useful tool for MRD detection and is traditionally used to monitor disease after bone marrow/stem cell transplantation (BMT/SCT). It appears, that evidence of MRD after allogeneic SCT in Ph+ patients is a poor prognostic sign.67,68 Wassmann et al.69 investigated the effect of imatinib to lower the probability of relapse in this setting and started imatinib treatment after re-conversion to MRD-positivity after SCT within a phase II trial. BCR-ABL transcripts became undetectable by both quantitative and nested RT-PCR in 15/29 (52%) patients. This was associated with a sustained remission whereas MRD persistence 6-10 weeks after start of Imatinib treatment correlated with an almost certain relapse. In addition, Pane et al.70 demonstrated that early quantification of residual disease before SCT is a prognostic parameter in Ph+ ALL. Leguay et al. presented data from the GRAAL AFR03 study71 in which imatinib combined with high dose chemotherapy improved molecular remission before transplantation and led to an improved outcome. MRD as indicator of impending relapse Outcome in adult patients with relapsed ALL is extremely poor, even if a second remission is achieved.72 Molecular detection of an imminent relapse may help to initiate salvage therapy before hematological relapse with a lower tumour burden and therefore possibly improve treatment results. The power of MRD monitoring as an indicator of an imminent relapse was prospectively evaluated in 105 MRD negative patients after consolidation treatment within the GMALL trials.61 From a total of 28 out of 105 patients (27%) who converted to MRD positivity, 17/28 (61%) have so far relapsed with a median time to relapse of 9.5 months after MRD conversion. | 170 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) 100 100 80 80 DFS (%) DFS (%) Vienna, Austria, June 7-10, 2007 60 40 20 day+11 p(trend)<0.001 0 0 1 2 3 4 5 60 40 20 week+16 p<0.001 0 0 1 Years MRD negative <10-2 ≥10-2 3-year DFS (95% CI) 91.7 (76.1-100) 51.9 (21.4-82.4) 33.1 (18.7-47.5) 2 3 4 Years MRD negative/<10-4 ≥10-1 3-year DFS (95%) 65.5 (53.9-77.1) 12.2 (0.0-27.4) Figure 1. Probability of disease-free survival (DFS) according to MRD results during induction (day +11)and after start of consolidation (week 16) in adults treated according to the GMALL 06/99 or 07/03 protocol (see for details59) In 15 of those patients, MRD was detectable within the quantitative range of PCR in hematological remission. Thirtheen of these patients (89%) relapsed after a median interval of 4.1 months. Of the 77 continuously MRD negative patients, only 5 (6%) have relapsed. Therefore, conversion to quantifiable MRD positivity during early postconsolidation was highly predictive of subsequent relapse. In the ongoing GMALL 07/03 trial, salvage treatment should be started at the time of re-occurrence of quantifiable MRD. olds. Precise MRD thresholds for risk-group assignment have to be defined for each treatment protocol. Treatment blocks before the critical MRD sampling. time-points cannot be changed because this directly influences the prognostic value and discriminative thresholds.73 3. preferably at least two time-points should be chosen for MRD-based risk stratification because confirmation of the MRD result by the second improves accuracy, particularly when MRD levels are around the discriminative threshold. Requirements for an MRD based risk stratification Treatment options for MRD-based risk-groups In both childhood and adult ALL, MRD quantification can be used to evaluate the treatment response and therefore allow the identification of low-risk (LR) and high-risk (HR) patients who may benefit from therapy reduction or therapy intensification respectively. Several considerations are important when MRD information from existing treatment protocols is developed into new clinical treatment protocols:16 1. the choice of the MRD technique, because different techniques may differ in sensitivity, optimal sampling time-point and applicability in multicenter trials. A switch-over between different MRD techniques should be avoided unless proof is provided that the MRD results are fully identical. High sensitive MRD techniques (at least 10–4) are required for accurate recognition of LR patients. However, if only HR patients need to be identified, less sensitive but cheaper and more rapid methodologies like GeneScanning of Ig/TCR gene rearrangements and 3to 4-colour flow cytometry may be suitable; 2. the optimal sampling time-points and thresh- Patients with a low risk of relapse might benefit from reduction of treatment intensity in order to avoid overtreatment. Overall shortening of treatment duration or omission of intensification cycles are possible options. The decision depends on the overall treatment intensity and on the time-point of MRDbased risk-stratification. Although earlier studies without maintenance therapy beyond the first year of treatment gave inferior results,74,75 this approach might be justified in MRD LR patients. By contrast, MRD HR patients may benefit from any kind of treatment intensification, including SCT, intensification cycles and experimental approaches. However, it is known that patients with high MRD levels before SCT76,77 are at high risk of relapse, so that attempts to minimize MRD levels before transplantation can be considered.71 For patients with an intermediate MRD course a third risk group can be defined. These intermediate risk patients, along with patients with suboptimal MRD assays that do not fulfil technical requirements for MRD-based risk assessment, should probably receive standard treat- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 171 | 12th Congress of the European Hematology Association ment according to the experience of the individual study.75 In these cases, MRD information at later time-points could identify MRD re-occurrence before clinical relapse allowing for an early salvage treatment.61 The relative sizes of MRD-based risk groups differ from those that were obtained in childhood trials. In pediatric patients, MRD-defined LR-groups make up 40% to 90% of patients, whereas only 5% to 15% belong to the MRD-HR-groups.6,7,13,22 In trials on adult ALL, the MRD-HR-group is larger and the MRD-LRgroup smaller, probably reflecting the differences in biology of the disease.59 Based on the results of the MRD studies protocol committees of several clinical trials on MRD in adult ALL patients included MRD into treatment stratification. Within the ongoing GMALL 07/03 trial patients with MRD levels consistently <10–4 after induction treatment and undetectable MRD after end of consolidation treatment form the MRD-LR group. Patients with persistent MRD levels >10–4 after induction (day +71) and/or during consolidation are allocated to the MRD-HR group.75,78 In MRD-LR patients, maintenance treatment is not given after the first year of therapy while the MRD-HR-group is eligible for allogeneic SCT. Bassan et al.63 describe an MRDoriented therapy for all t(4;11)neg/t(9;22)neg ALL patients. MRD positive patients (defined as MRD >10–4 before induction-consolidation cycle 6 and MRD positivity before cycle 8) are allocated to allogeneic or autologous SCT, whereas MRD negative patients receive standard maintenance regardless of classic risk factors. Four-year DFS was 76% in MRD negative patients compared with only 24% in the MRD positive group despite treatment intensification. The PETHEMA ALL-AR-03 trial79 focuses on high risk t(9;22)neg ALL and does not perform SCT in first complete remission in cases of standard cytologic response and MRD <0,05% after early consolidation. By contrast, patients with a slow cytologic response and/or MRD >0,05% after early consolidation later receive allogeneic SCT. Preliminary results indicate that prognosis of HR patients with adequate response to induction and adequate clearance of MRD does not worsen if allogeneic SCT is avoided. Conclusions MRD has been proven to be an independent prognostic factor in childhood and adult ALL. Quantitative PCR and flow cytometry are the most widely used techniques at the moment for MRD quantification although each has advantages and disadvantages that must be carefully considered. Precise MRD levels and optimal sampling time-points must also be defined for each treatment protocol before MRD-based risk stratification can be implemented. Whether or not patient outcome can be improved by integrating MRD into treatment decisions is currently the subject of several clinical trials. References 1. Gökbuget N, Hoelzer D, Arnold R, Bohme A, Bartram CR, Freund M, et al. Treatment of Adult ALL according to protocols of the German Multicenter Study Group for Adult ALL (GMALL). Hematol Oncol Clin North Am 2000;14:1307-25. 2. Hoelzer D, Thiel E, Loffler H, Buchner T, Ganser A, Heil G, et al. Prognostic factors in a multicenter study for treatment of acute lymphoblastic leukemia in adults. Blood. 1988;71:12331. 3. Larson RA, Dodge RK, Burns CP, Lee EJ, Stone RM, Schulman P, et al. A five-drug remission induction regimen with intensive consolidation for adults with acute lymphoblastic leukemia: cancer and leukemia group B study 8811. Blood 1995;85:2025-37. 4. Rowe JM, Buck G, Burnett AK, Chopra R, Wiernik PH, Richards SM, et al. Induction therapy for adults with acute lymphoblastic leukemia: results of more than 1500 patients from the international ALL trial: MRC UKALL XII/ECOG E2993. Blood 2005;106:3760-7. 5. Campana D, Pui CH. Detection of minimal residual disease in acute leukemia: methodologic advances and clinical significance. Blood 1995;85:1416-34. 6. Cave H, van der Werff ten Bosch, Suciu S, Guidal C, Waterkeyn C, Otten J, et al. Clinical significance of minimal residual disease in childhood acute lymphoblastic leukemia. European Organization for Research and Treatment of Cancer-Childhood Leukemia Cooperative Group. N Engl J Med 1998;339:591-8. 7. Coustan-Smith E, Behm FG, Sanchez J, Boyett JM, Hancock ML, Raimondi SC, et al. Immunological detection of minimal residual disease in children with acute lymphoblastic leukaemia. Lancet 1998;351:550-4. 8. Coustan-Smith E, Sancho J, Hancock ML, Boyett JM, Behm FG, Raimondi SC, et al. Clinical importance of minimal residual disease in childhood acute lymphoblastic leukemia. Blood 2000;96:2691-6. 9. Coustan-Smith E, Sancho J, Behm FG, Hancock ML, Razzouk BI, Ribeiro RC, et al. Prognostic importance of measuring early clearance of leukemic cells by flow cytometry in childhood acute lymphoblastic leukemia. Blood 2002;100:52-8. 10. Dworzak MN, Froschl G, Printz D, Mann G, Potschger U, Muhlegger N, et al. Prognostic significance and modalities of flow cytometric minimal residual disease detection in childhood acute lymphoblastic leukemia. Blood 2002;99:1952-8. 11. Nyvold C, Madsen HO, Ryder LP, Seyfarth J, Svejgaard A, Clausen N, et al. Precise quantification of minimal residual disease at day 29 allows identification of children with acute lymphoblastic leukemia and an excellent outcome. Blood 2002;99:1253-8. 12. Panzer-Grumayer ER, Schneider M, Panzer S, Fasching K, Gadner H. Rapid molecular response during early induction chemotherapy predicts a good outcome in childhood acute lymphoblastic leukemia. Blood 2000;95:790-4. 13. van Dongen JJ, Seriu T, Panzer-Grumayer ER, Biondi A, Pongers-Willemse MJ, Corral L, et al. Prognostic value of minimal residual disease in acute lymphoblastic leukaemia in childhood. Lancet 1998;352:1731-8. 14. Campana D. Determination of minimal residual disease in leukaemia patients. Br J Haematol 2003;121:823-38. 15. Campana D, Coustan-Smith E. Minimal residual disease studies by flow cytometry in acute leukemia. Acta Haematol 2004;112:8-15. 16. Hoelzer D, Gökbuget N, Ottmann O, Pui CH, Relling MV, Appelbaum FR, et al. Acute lymphoblastic leukemia. Hematology (Am Soc Hematol Educ Program). 2002;162-92. 17. van der Velden VHJ, Hochhaus A, Cazzaniga G, Szczepanski T, Gabert J, van Dongen JJM. Detection of minimal residual disease in hematologic malignancies by real-time quantitative PCR: principles, approaches, and laboratory aspects. Leukemia 2003;17:1013-34. 18. van der Velden VHJ, Boeckx N, van Wering ER, van Dongen JJ. Detection of minimal residual disease in acute leukemia. J Biol Regul Homeost Agents 2004;18:146-54. 19. van Wering ER, van der Linden-Schrever BE, Szczepanski T, Willemse MJ, Baars EA, Wijngaarde-Schmitz HM, et al. | 172 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. Regenerating normal B-cell precursors during and after treatment of acute lymphoblastic leukaemia: implications for monitoring of minimal residual disease. Br J Haematol 2000;110: 139-46. Campana D, Coustan-Smith E. Advances in the immunological monitoring of childhood acute lymphoblastic leukaemia. Best Pract Res Clin Haematol 2002;15:1-19. Dworzak MN, Fritsch G, Fleischer C, Printz D, Froschl G, Buchinger P, et al. Multiparameter phenotype mapping of normal and post-chemotherapy B lymphopoiesis in pediatric bone marrow. Leukemia 1997;11:1266-73. Dworzak MN, Fröschl G, Printz D, Mann G, Pötschger U, Mühlegger N, et al. for the Berlin-Frankfurt-Münster Study Group. Immunological detection of minimal residual disease in acute lymphoblastic leukemia. Blood 2002;99:1952-8. Veltroni M, De Zen L, Sanzari MC, Maglia O, Dworzak MN, Ratei R, et al. Expression of CD58 in normal, regenerating and leukemic bone marrow B cells: implications for the detection of minimal residual disease in acute lymphocytic leukemia. Haematologica 2003;88:1245-52. Lucio P, Gaipa G, van Lochem EG, van Wering ER, PorwitMacDonald A, Faria T, et al. BIOMED-I concerted action report: flow cytometric immunophenotyping of precursor BALL with standardized triple-stainings. BIOMED-1 Concerted Action Investigation of Minimal Residual Disease in Acute Leukemia: International Standardization and Clinical Evaluation. Leukemia 2001;15:1185-92. Kerst G, Kreyenberg H, Roth C, Well C, Dietz K, CoustanSmith E, et al. Concurrent detection of minimal residual disease (MRD) in childhood acute lymphoblastic leukaemia by flow cytometry and real-time PCR. Br J Haematol 2005;128: 774-82. Malec M, van der Velden VHJ, Bjorklund E, Wijkhuijs JM, Soderhall S, Mazur J, et al. Analysis of minimal residual disease in childhood acute lymphoblastic leukemia: comparison between RQ-PCR analysis of Ig/TcR gene rearrangements and multicolor flow cytometric immunophenotyping. Leukemia 2004;18:1630-6. Robillard N, Cave H, Mechinaud F, Guidal C, Garnache-Ottou F, Rohrlich PS, et al. Four-color flow cytometry bypasses limitations of IG/TCR polymerase chain reaction for minimal residual disease detection in certain subsets of children with acute lymphoblastic leukemia. Haematologica 2005;90:151623. Gaipa G, Basso G, Maglia O, Leoni V, Faini A, Cazzaniga G, et al. Drug-induced immunophenotypic modulation in childhood ALL: implications for minimal residual disease detection. Leukemia. 2005;19:49-56. Chen JS, Coustan-Smith E, Suzuki T, Neale GA, Mihara K, Pui CH, et al. Identification of novel markers for monitoring minimal residual disease in acute lymphoblastic leukemia. Blood 2001;97:2115-20. Szczepanski T, Langerak AW, Wolvers-Tettero IL, Ossenkoppele GJ, Verhoef G, Stul M, et al. Immunoglobulin and T cell receptor gene rearrangement patterns in acute lymphoblastic leukemia are less mature in adults than in children: implications for selection of PCR targets for detection of minimal residual disease. Leukemia 1998;12:1081-8. Szczepanski T, Beishuizen A, Pongers-Willemse MJ, Hahlen K, van Wering ER, Wijkhuijs AJ, et al. Cross-lineage T cell receptor gene rearrangements occur in more than ninety percent of childhood precursor-B acute lymphoblastic leukemias: alternative PCR targets for detection of minimal residual disease. Leukemia 1999;13:196-205. Szczepanski T, Flohr T, van der Velden VHJ, Bartram CR, van Dongen JJ. Molecular monitoring of residual disease using antigen receptor genes in childhood acute lymphoblastic leukaemia. Best Pract Res Clin Haematol 2002;15:37-57. Szczepanski TP-WMJ, Langerak AW, Harts WA, Wijkhuijs AJM, van Wering ER, van Dongen JJM. Ig heavy chain gene rearrangements in T-cell acute lymphoblastic leukemia exhibit predominant DH6-19 and DH7-27 gene usage, can result in complete V-D-J rearrangements, and are rare in T-cell receptor alpha beta lineage. Blood 1999;93:4079-85. van Dongen JJ, Wolvers-Tettero IL. Analysis of immunoglobulin and T cell receptor genes. Part II: Possibilities and limitations in the diagnosis and management of lymphoproliferative diseases and related disorders. Clin Chim Acta 1991;198:93174. van Dongen JJ, Wolvers-Tettero IL. Analysis of immunoglobulin and T cell receptor genes. Part I: Basic and technical aspects. Clin Chim Acta 1991;198:1-91. Kneba M, Bolz I, Linke B, Hiddemann W. Analysis of 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. rearranged T-cell receptor beta-chain genes by polymerase chain reaction (PCR) DNA sequencing and automated high resolution PCR fragment analysis. Blood 1995;86:3930-7. Linke B, Bolz I, Fayyazi A, von Hofen M, Pott C, Bertram J, et al. Automated high resolution PCR fragment analysis for identification of clonally rearranged immunoglobulin heavy chain genes. Leukemia. 1997;11:1055-62. van Dongen JJ, Langerak AW, Brüggemann M, Evans PA, Hummel M, Lavender FL, et al. Design and standardization of PCR primers and protocols for detection of clonal immunoglobulin and T-cell receptor gene recombinations in suspect lymphoproliferations: report of the BIOMED-2 Concerted Action BMH4-CT98-3936. Leukemia 2003;17: 2257-317. Beishuizen A, Verhoeven MA, van Wering ER, Hahlen K, Hooijkaas H, van Dongen JJ. Analysis of Ig and T-cell receptor genes in 40 childhood acute lymphoblastic leukemias at diagnosis and subsequent relapse: implications for the detection of minimal residual disease by polymerase chain reaction analysis. Blood 1994;83:2238-47. Szczepanski T, van der Velden VHJ, Raff T, et al. Comparative analysis of T-cell receptor gene rearrangements at diagnosis and relapse of T-cell acute lymphoblastic leukemia (T-ALL) shows high stability of clonal markers for monitoring of minimal residual disease and reveals the occurrence of secondary T-ALL. Leukemia 2003;17:2149-56. Szczepanski T, Willemse MJ, Brinkhof B, van Wering ER, van der Burg M, van Dongen JJM. Comparative analysis of Ig and TCR gene rearrangements at diagnosis and at relapse of childhood precursor-B-ALL provides improved strategies for selection of stable PCR targets for monitoring of minimal residual disease. Blood 2002;99:2315-23. Brüggemann M, Droese J, Bolz I, Luth P, Pott C, von Neuhoff N, et al. Improved assessment of minimal residual disease in B cell malignancies using fluorogenic consensus probes for realtime quantitative PCR. Leukemia 2000;14:1419-25. Brüggemann M, van der Velden VHJ, Raff T, Droese J, Ritgen M, Pott C, et al. Rearranged T-cell receptor beta genes represent powerful targets for quantification of minimal residual disease in childhood and adult T-cell acute lymphoblastic leukemia. Leukemia 2004;18:709-19. Donovan JW, Ladetto M, Zou G, Neuberg D, Poor C, Bowers D, et al. Immunoglobulin heavy-chain consensus probes for real-time PCR quantification of residual disease in acute lymphoblastic leukemia. Blood 2000;95:2651-8. van der Velden VHJ, Wijkhuijs JM, Jacobs DC, van Wering ER, van Dongen JJM. T cell receptor gamma gene rearrangements as targets for detection of minimal residual disease in acute lymphoblastic leukemia by real-time quantitative PCR analysis. Leukemia 2002;16:1372-80. van der Velden VHJ, Willemse MJ, van der Schoot CE, Hahlen K, van Wering ER, van Dongen JJM. Immunoglobulin kappa deleting element rearrangements in precursor-B acute lymphoblastic leukemia are stable targets for detection of minimal residual disease by real-time quantitative PCR. Leukemia 2002;16:928-36. van der Velden VHJ, Brüggemann M, Hoogeveen PG, de Bie M, Hart PG, Raff T, et al. TCRB gene rearrangements in childhood and adult precursor-B-ALL: frequency, applicability as MRD-PCR target, and stability between diagnosis and relapse. Leukemia 2004; 18:1971-80. van der Velden VH, Cazzaniga G, Schrauder A, Hancock J, Bader P, Panzer-Grumayer ER, et al. Analysis of minimal residual disease by Ig/TCR gene rearrangements: Guidelines for interpretation of real-time quantitative PCR data. Leukemia 2007;Feb 8; [Epub ahead of print] van Dongen JJ, Macintyre EA, Gabert JA, Delabesse E, Rossi V, Saglio G, et al. Standardized RT-PCR analysis of fusion gene transcripts from chromosome aberrations in acute leukemia for detection of minimal residual disease. Report of the BIOMED-1 Concerted Action: investigation of minimal residual disease in acute leukemia. Leukemia 1999;13:1901-28. Breit TM, Beishuizen A, Ludwig WD, Mol EJ, Adriaansen HJ, van Wering ER, et al. tal-1 deletions in T-cell acute lymphoblastic leukemia as PCR target for detection of minimal residual disease. Leukemia 1993;7:2004-11. Burmeister T, Marschalek R, Schneider B, Meyer C, Gokbuget N, Schwartz S, et al. Monitoring minimal residual disease by quantification of genomic chromosomal breakpoint sequences in acute leukemias with MLL aberrations. Leukemia 2006;20:451-7. van der Velden VHJ, Boeckx N, Gonzalez M, Malec M, Barbany G, Lion T, et al. Differential stability of control gene Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 173 | 12th Congress of the European Hematology Association 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. and fusion gene transcripts over time may hamper accurate quantification of minimal residual disease-a study within the Europe Against Cancer Program. Leukemia 2004;18:884-6. Beillard E, Pallisgaard N, van der Valden VH, Bi W, Dee R, van der Schott E, et al. Evaluation of candidate control genes for diagnosis and residual disease detection in leukemic patients using 'real-time' quantitative reverse-transcriptase polymerase chain reaction (RQ-PCR) - a Europe against cancer program. Leukemia 2003;17:2474-86. Gabert J, Beillard E, van der Velden VHJ, Bi W, Grimwade D, Pallisgaard N, et al. Standardization and quality control studies of real-time quantitative reverse transcriptase polymerase chain reaction of fusion gene transcripts for residual disease detection in leukemia - a Europe Against Cancer program. Leukemia 2003;17:2318-57. Boettcher S, Irmer S, Lueschen S, Ritgen M, Raff T, Goekbuget N, et al. Sensitivity and applicability of six-color flow cytometry is comparable to ASO-primer-real-time PCR (RQ-PCR) for minimal residual disease (MRD) monitoring in adult acute lymphoblastic leukemia (ALL) - A comparative analysis in 70 Patients from the German Multicenter Study Group for Adult Acute Lymphoblastic Leukemia (GMALL). ASH Annual Meeting Abstracts 2006;108:2287. Krejcikova K, Muzikova K, Fronkova E, Kalinova M, Reznickova L, Zuna J, et al. Limited reliability of Ig/TCR based MRD monitoring in BCR/ABL-positive childhood ALL: comparison to quantitative fusion transcript detection. ASH Annual Meeting Abstracts 2006;108:2340. Böttcher S, Ritgen M, Pott C, Bruggemann M, Raff T, Stilgenbauer S, et al. Comparative analysis of minimal residual disease detection using four-color flow cytometry, consensus IgH-PCR, and quantitative IgH PCR in CLL after allogeneic and autologous stem cell transplantation. Leukemia 2004;18: 1637-45. Neale GA, Coustan-Smith E, Stow P, Pan Q, Chen X, Pui CH, et al. Comparative analysis of flow cytometry and polymerase chain reaction for the detection of minimal residual disease in childhood acute lymphoblastic leukemia. Leukemia 2004;18: 934-8. Brüggemann M, Raff T, Flohr T, Gokbuget N, Nakao M, Droese J, et al. Clinical significance of minimal residual disease quantification in adult patients with standard-risk acute lymphoblastic leukemia. Blood 2006;107:1116-23. Mortuza FY, Papaioannou M, Moreira IM, Coyle LA, Gameiro P, Gandini D, et al. Minimal residual disease tests provide an independent predictor of clinical outcome in adult acute lymphoblastic leukemia. J Clin Oncol 2002;20:1094-104. Raff T, Gökbuget N, Lüschen S, Reutzel R, Ritgen M, Irmer S, et al. Molecular relapse in adult standard-risk ALL patients detected by prospective MRD monitoring during and after maintenance treatment: data from the GMALL 06/99 and 07/03 trials. Blood 2007;109:910-15. Vidriales MB, Perez JJ, Lopez-Berges MC, Gutierrez N, Ciudad J, Lucio P, et al. Minimal residual disease in adolescent (older than 14 years) and adult acute lymphoblastic leukemias: early immunophenotypic evaluation has high clinical value. Blood 2003;101:4695-700. Bassan R, Spinelli O, Oldani E, Intermesoli T, Tosi M, Rossi G, et al. Minimal Residual Disease (MRD) and Risk-Oriented Therapy in Adult Acute Lymphoblastic Leukemia (ALL). ASH Annual Meeting Abstracts 2005;106:1836. Brisco J, Hughes E, Neoh SH, Sykes PJ, Bradstock K, Enno A, et al. Relationship between minimal residual disease and outcome in adult acute lymphoblastic leukemia. Blood 1996; 12: 5251-6. Gameiro P, Mortuza FY, Hoffbrand AV, Foroni L. Minimal residual disease monitoring in adult T-cell acute lymphoblastic leukemia: a molecular based approach using T-cell receptor g and d gene rearrangements. Haematologica 2002;87:1126-34. 66. Krampera M, Vitale A, Vincenzi C, Perbellini O, Guarini A, Annino L, et al. Outcome prediction by immunophenotypic minimal residual disease detection in adult T-cell acute lymphoblastic leukaemia. Br J Haematol 2003;120:74-9. 67. Miyamura K, Tanimoto M, Morishima Y, Horibe K, Yamamoto K, Akatsuka M, et al. Detection of Philadelphia chromosome-positive acute lymphoblastic leukemia by polymerase chain reaction: possible eradication of minimal residual disease by marrow transplantation. Blood 1992;79:136670. 68. Radich J, Gehly G, Lee A, Avery R, Bryant E, Edmands S, et al. Detection of bcr-abl transcripts in Philadelphia chromosomepositive acute lymphoblastic leukemia after marrow transplantation. Blood 1997;89:2602-9. 69. Wassmann B, Pfeifer H, Stadler M, Bornhauser M, Bug G, Scheuring UJ, et al. Early molecular response to post-transplantation imatinib determines outcome in MRD+ Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). Blood 2005;106:458-63. 70. Pane F, Cimino G, Izzo B, Camera A, Vitale A, Quintarelli C, et al. Significant reduction of the hybrid BCR/ABL transcripts after induction and consolidation therapy is a powerful predictor of treatment response in adult Philadelphia-positive acute lymphoblastic leukemia. Leukemia 2005;19:628-35. 71. Leguay T, Witz F, De Botton S, Gabert J, Cayuela JM, Macintyre E, et al.Post-remission therapy with Imatinib and HAM improve MRD before tansplant for patients with Philadelphia-positive acute lymphoblastic leukemia (Ph+ALL): Results of the GRAALL AFR03 Study. ASH Annual Meeting Abstracts 2006;108:1877. 72. Fielding AK, Richards SM, Chopra R, Lazarus HM, Litzow MR, Buck G, et al. Medical Research Council of the United Kingdom Adult ALL Working Party and the Eastern Cooperative Oncology Group. Outcome of 609 adults after relapse of acute lymphoblastic leukemia (ALL); an MRC UKALL12/ECOG 2993 study. Blood 2007;109:944-50. 73. Winick N, Borowitz MJ, Devidas M, Martin PL, Pullen J, Hunger SP, et al. Changes in the delivery of standard chemotherapeutic agents during induction affect early measures of minimal residual disease (MRD): POG 9900 for patients with B-precursor low and standard risk ALL. ASH Annual Meeting Abstracts 2006;108:2272. 74. Hoelzer D, Gökbuget N. New approaches to acute lymphoblastic leukemia in adults: where do we go? Semin Oncol 2000;27:540-59. 75. Gökbuget N, Kneba M, Raff T, Brüggemann M, Scheuring U, Reutzel R, et al. Risk-adapted treatment according to minimal residual disease in adult ALL. Best Pract Res Clin Haematol 2002;15:639-52. 76. Dombret H, Gabert J, Boiron JM, Rigal-Huguet F, Blaise D, Thomas X, et al. Outcome of treatment in adults with Philadelphia chromosome-positive acute lymphoblastic leukemia-results of the prospective multicenter LALA-94 trial. Blood 2002;100:2357-66. 77. Knechtli CJ, Goulden NJ, Hancock JP, Grandage VL, Harris EL, Garland RJ, et al. Minimal residual disease status before allogeneic bone marrow transplantation is an important determinant of successful outcome for children and adolescents with acute lymphoblastic leukemia. Blood 1998;92:4072-9. 78. Gökbuget N, Raff R, Brüggemann M, Flohr T, Scheuring U, Pfeifer H, et al. Risk/MRD adapted GMALL trials in adult ALL. Ann Hematol 2004;83 Suppl 1:S129-S31. 79. Ribera J, Oriol A, Morgades M, Sarra J, Brunet S, Llorente A, et al. Treatment of high-risk (HR) philadelphia chromosomenegative (Ph-) adult acute lymphoblastic leukemia (ALL) according to classical risk factors and minimal residual disease (MRD). Interim Results of the PETHEMA ALL-AR-03 Trial. ASH Annual Meeting Abstracts 2006;108:1872. | 174 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Acute Myeloid Leukemia Targeting critical pathways in leukemia stem cells S. Anand W-I. Chan B.T. Kvinlaug B.J.P. Huntly Department of Hematology, University of Cambridge, Cambridge Institute for Medical Research, Hills Road, Cambridge, UK Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:175-182 ecently, many cancers have been demonstrated to be completely dependent upon a small population of putative cancer stem cells for their continued growth and propagation.1 The existence of cancer stem cells was first demonstrated in acute myeloid leukemia (AML), by Dick and colleagues in Toronto.2,3 Leukemic blasts from patients with a spectrum of phenotypic subtypes of AML (M0-M7, excluding M3, by the FAB classification) were flow sorted into an immature fraction which was CD34+ and CD38– and a more mature fraction which was both CD34+ and CD38+. Following xenotransplantation into immunocompromised non-obese diabetic-severe combined immunodeficiency (NOD-SCID) mice, which are known to support the engraftment of normal hematopoietic cells, it was demonstrated that only the immature (CD34+/CD38–) fraction could transfer the leukemia. This putative SCID leukemia initiating cell (SL-IC, equivalent to the leukemia stem cell or LSC) population shares a surface phenotype (CD34+/ CD38–) with the stem cell population which regenerates normal human hematopoiesis in NOD-SCID mice, the SCID repopulating cell (SRC). Based on these findings, the authors proposed that AML arranges itself as a developmental hierarchy and that the normal hematopoietic stem cell was the likely target cell for transformation.3 Subsequently, LSCs have also been demonstrated in acute lymphoblastic leukemia (ALL),4 and cancer stem cells have been demonstrated in a number of solid organ tumours such as breast,5 CNS tumors,6 prostate7 and colon8,9 suggesting that the majority of malignancies are dependent upon such a compartment. Survival rates for the majority of patients with AML have not improved much in the last twenty years,10 and any improvement is probably due to the risk stratification and changes in treatment of young patients with favourable cytogenet- R ics, along with overall improvements in general supportive care.11 Two drugs, an anthracycline and cytosine arabinoside (Ara-C), have provided the basis of AML therapy for this entire period,11 although newer agents are currently under investigation.12 Therefore, most patients with AML continue to die following relapse of their disease and it is the LSC compartment that is responsible for both relapse and the development of resistance to therapy that often accompanies it. This suggests that current AML therapeutic regimens, which often lead to complete morphological remissions in patients, preferentiality target bulk leukemia cells and tend to spare the LSC compartment (Figure 1). Leukemia stem cells therefore represent the critical targets for eradication of leukemia. Unfortunately, little is known of the biology of these cells. Particularly important for any therapeutic strategy is to recognise that the targeted pathway should have efficacy against LSCs but preferentially spare normal hematopoietic stem cell (HSC) function. Recently in vitro and in vivo assays which can assess both leukemic and normal hematopoietic stem cell function have been developed (see later), allowing for the development of such therapies.13 This article will outline current knowledge and suggest how leukemia stem cells might be targeted for future therapeutic gain. Targeting leukemia stem cells The importance of specifically targeting LSCs whilst relatively sparing normal HSC function has already been emphasised. Unfortunately, our knowledge of LSC biology and even normal HSC function is relatively limited. To specifically target the LSC we must therefore improve our knowledge of the basic biology of these cells and of potential differences between normal and leukemic stem cells. Already, we know of differences in surface antigen expression and current strategies for therapeutically exploiting this are Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 175 | 12th Congress of the European Hematology Association underway (see below). The primary functions of the HSC are to maintain both the stem cell compartment and adequate numbers of the terminally differentiated effector cells of the blood. The control of these functions is complex and involves the interaction between cell autonomous programmes within the HSC and cell non-autonomous signals from the stem cell niche. However, the number of potential cell fate decisions available to a stem cell are relatively few. A stem cell may quiesce, self-renew, differentiate or apoptose (Figure 2) and it is the delicate balance between these interconnected processes which allows us to dramatically respond throughout life to stresses such as severe infection and bleeding where increased numbers of mature effector cells are required without depleting the stem cell reserve. Basically, the same cell fate decisions are available to leukemia stem cells, although the processes controlling the decisions are dysregulated (Figure 2). Targeting these processes, based upon a differential reliance of LSCs and normal HSCs on specific pathways, may allow for preferential eradication of the LSC compartment. A list of such potential targets is summarised in Table 1. Targeting differences in surface phenotype Although both the LSC in AML and normal HSCs express CD34+ but not CD38–, there are differences between the LSC and HSC surface phenotype. Whilst the normal HSC is lin–, CD 34+/38–/90+/123– /lo /117+/71+/HLA-DR– , the majority of AML LSC are lin–, CD34+/38–/90–/123+/117–/71+/HLA-DR– 2,3,14,15-17 (see Figure 3, panel A). Recent therapeutic success with monoclonal antibodies and immunoconjugate therapy, for example in CD20+ lymphoproliferative disorders with Rituximab (Mabthera®) and in AML with gemtuzumab ozogamicin (GO, Myelotarg®), have demonstrated the potential efficacy of targeting cells based on their surface phenotype. Therefore, the differences already noted between the AML LSC and normal HSC make this an attractive proposition in AML therapy. Interestingly, a recent report suggests that the majority of AML LSC actually express CD33,18 the target of GO. Unfortunately however, CD33 also appears to be expressed on the majority of HSC.18 This suggests that GO may not be a specific agent targeting AML stem cells, but it may explain the high complete remission rate seen with this agent and the occasional cases of prolonged cytopenia fol- Table 1. Potential LSC targets. Potential LSC targets Comments CD123 (IL-3 receptor α) Present on most LSC but absent or only present at low levels on normal HSC. A fusion immunoconjugate of the cognate ligand of the receptor, IL-3, to the Diptheria toxin, DT388IL3 is currently in clinical trials. The AP-1 transcriptional pathway Both JunB and c-Jun are AP1 transcription factors. 48 The AP-1 complex consists of either a Jun-Jun homodimer or a Jun-Fos heterodimmer. T his complex regulates the expression of multiple genes essential for cell proliferation, differentiation and apoptosis. c-Jun appears to direct myelomonocytic differentiation whilst JunB is a stem cell tumour suppressor. Decreased expression of both c-Jun and JunB in AML appears to contribute to the leukemic phenotype and restoration of their levels may annul this phenotype. mTOR The mammalian target of rapamycin is a downstream signaling component of the PI3K-AKT 29,30,70 pathway and mediates cellular responses to stresses such as DNA damage and nutrient deprivation through phosphorylation of substrates such as p70S6K and 4EBP. The PI3K-AKT pathway is constitutively activated in AML and recent mouse studies suggest that PI3K activity may have a role in the self-renewal of LSC. Inhibitors of mTOR, such as Rapamycin, exist and are currently in randomized trials for AML NF-κB Nuclear Factor kappa B is a dimeric transcription family formed by combination of 5 members which share a related DNA binding element. NF-kB controls gene expression of a number of targets in response to stimuli such as cytokines, growth factors, stress stimuli, and viral and bacterial infection. It is frequently dysregulated in cancer and is constitutively activated in the AML LSC compartment where it appears to be anti-apoptotic, but not the normal HSC compartment. NF-κB is retained in an inactive form under basal conditions by the inhibitor of kB (I-κB) family of proteins, which sequester the inactive dimers in the cytoplasm. Most stimuli activate NF-κB by stimulating the I-κB kinase (IKK) family of proteins, which phosphorylate the I-κB proteins and target them for ubiquitination and degradation in the proteasome. Therapies which target this pathway, such as Parthenolide, proteasome inhibitors and IKK inhibitors are currently in clinical trials. 57-60 CD44 CD44 is a cell surface glycoprotein involved in cell/cell and cell/matrix interactions, and is widely expressed on a number of tumours. CD44 is present on AML LSC and ligation of this receptor with an activating antibody (H90) appears to direct differentiation and loss of LSC activity. 67,68 | 176 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Reference 20 Vienna, Austria, June 7-10, 2007 A A Current Chemotherapy Recurrence of disease B Targeted LSC HSC : CD34+/38-/ CD90+/123-/Io/117+ CD 71+/HLA-DR- HSC LSC Normal Leukeamic LSC : CD34+/38-/ CD90-/123+/117+ CD 71+/HLA-DR- Tumor involution Targeted LSC + Conventional therapy Disease remission B Tumor debulking Leukemia stem cell Non-clonogenic leukemia cell HSC Figure 1. Targeting the leukemia stem cell in AML therapy. (A) Current therapies for AML usually result in a significant decrease in leukemic burden, often a complete morphological response. However, the majority of patients relapse. This suggests that current therapies kill the nonclonogenic leukemic cells while sparing the LSC compartment. (B) Specifically targeting the LSC compartment, either alone or more probably in combination with conventional AML therapy, should lead to more durable remissions and improved survival in AML. CD123/ IL-3 receptor α Monoclonal Ab/ Immunoconjugate i.e. IL3-Diptheria toxin Normal progeny LSC Leukemic progeny C HSC Quiescence Differentiation Normal progeny Niche D LSC Self-renewal Leukemic progeny Apoptosis Figure 2. Cell fate decisions available to a leukemia stem cell. A leukemia stem cell and its specific niche are shown. Similarly to a normal HSC, intrinsic cell-autonomous cues and extrinsic interactions between the LSC and the niche determine the fate of the LSC. In addition, there are the same, limited numbers of cell fate decisions available to the LSC: to quiesce, to differentiate, to self-renew or to apoptose. Targeting differences in these processes between the LSC and the HSC compartment may help to eradicate leukemia stem cells (see text). lowing GO treatment.19 CD123, the IL3α receptor is expressed on most LSCs but not, or only at low levels, on HSCs16,18, its expression being upregulated on later normal myeloid progenitors. To take advantage of this, and selectively target AML LSCs, a specific fusion of IL3 and a diphtheria toxin (DT388IL3) has been generated by Hogge, Frankel and colleagues.20 Preclinical studies demonstrated in vitro sensitivity of AML- HSC Tumor involution Normal progeny Figure 3. Targeting the AML LSC surface phenotype. (A) Differences exist between the surface phenotype of the normal HSC and the LSC (shown in red in the figure). Where there is expression of an antigen on an LSC but not an HSC (i.e. for CD123, the IL3α receptor), the use of a monoclonal antibody or immunoconjugate specific to this antigen will target the LSC but not the normal HSC compartment. Targeting this compartment will lead to selective LSC depletion or eradication (B). Even if, as is the case with CD123, the antigen is expressed later during normal ontogeny (where the MoAb or immunoconjugate will target a more committed normal progenitor cell, in this instance a myeloid progenitor cell), this will simply lead to transient cytopenias, with the progenitor compartment eventually regenerated by the normal HSC. However, targeting the LSC should help to eradicate the leukemia, as decrease or preferentially eradication of the LSC compartment will prevent recurrence of AML post-therapy (C and D). Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 177 | 12th Congress of the European Hematology Association colony forming cells (CFC), AML-long-term culture initiating cells (LT-CIC) and AML-suspension culture initiating cells (SC-IC) to DT388IL3, whereas normal bone marrow showed no change in LT-CIC, minimal change in SC-IC and some decrease in CFC, but to a lesser degree than in AML.20 In addition, ex vivo treatment of AML cells with DT388IL3 dramatically decreased the engraftment of disease in NOD-SCID mice, and in vivo administration to NOD-SCID recipients of AML cell inoculums was demonstrated to be safe, significantly decreased AML engraftment and in 50% of cases eradicated the disease completely.20 Furthermore, normal bone marrow cells treated ex vivo with DT388IL3 showed no difference in engraftment in NOD-SCID mice compared to untreated controls20 (Figure 3 panels B-D). Further toxicity studies have since shown an acceptable side effect profile in Cynomolgus monkeys,21 and DT388IL3 is currently being assessed in a phase I/II clinical trial in patients with relapsed or refractory AML.22 In this poor prognostic grouping, preliminary data suggests efficacy in clearing marrow blasts with acceptable toxicity and further dose escalation is planned.22 Targeting self-renewal/quiescence in LSCs Unlimited self-renewal potential is one of the hallmarks of cancer,23 but is also a defining characteristic of normal stem cells. Currently, the mechanisms of self renewal in malignant cells are poorly understood. Pathways such as the HOX gene,24,25 WNT/βCatenin,26,27 Notch,28 PTEN,29,30 Hedgehog31 and BMI132,33 pathways have all been found to be mutated in human cancers and these same pathways are also implicated in the maintenance of normal stem cells.29,30,33-38 Although their involvement in normal stem cell self-renewal makes these pathways less attractive candidates, the finding that they are frequently mutated or aberrantly activated suggests that they may function differently in malignant and normal stem cells, and thus may be selectively targeted in LSCs. In addition, β-catenin has recently been shown to be dispensable for hematopoiesis in a mouse model39 and two recent reports have demonstrated that constitutive Wnt signaling actually impairs normal HSC function.40,41 Overall, these data suggest as an example that the WNT/β-Catenin pathway, known to be constitutively activated in AML,15 may potentially be beneficially targeted in the LSC compartment.42 Recent evidence has demonstrated that certain leukemia-associated fusion oncogenes, such as MOZ-TIF2,43 MLL-ENL44 and MLL-AF945 may alter the properties of committed murine myeloid progenitors and confer self-renewal when retrovirally expressed within this compartment. This ultimately leads to the generation of AML from the committed myeloid progenitor compartment in bone marrow transplant recipient mice. Existing evidence in humans also suggests that a progenitor compartment may be transformed to generate leukemia.4,27 Overall, these data challenge the previously held belief which suggested the HSC was the only target for transformation in acute leukemias. However, the ability to alter self-renewal of murine committed myeloid progenitors was shown to be missing in another representative and fully transforming leukemia-associated oncogene, BCR-ABL.43 As the oncogenes MOZ-TIF2, MLL-ENL and MLL-AF9 are fusions of transcriptionally active proteins, whereas BCR-ABL encodes a constitutively activated tyrosine kinase, this suggests that MOZ-TIF2, MLL-ENL and MLL-AF9 (re)-establish a transcriptional programme which leads to selfrenewal. Using this technical platform, it should be possible to identify the transcriptional programmes associated with this self-renewal, using expression analysis following the expression of these oncogenes in committed myeloid progenitors. This in turn may identify both known and novel genes and pathways that are commonly activated to mediate self-renewal in AML. Furthermore, examination of the reliance of normal HSC on these pathways may then identify pathways differentially used by the HSC and LSC compartments that can be therapeutically targeted. A self-renewal signature has recently been demonstrated by Armstrong and colleagues for MLL-AF9 using such an approach, confirming the importance of the Hoxa cluster and suggesting newer candidate selfrenewal genes such as Mef2c.45 Another transcriptional pathway which appears to alter self-renewal in myeloid malignancies is that associated with the AP-1 transcription factor JunB. JunB is a known transcriptional regulator of myelopoiesis and also a tumour suppressor gene.46 In further experiments, enforced expression of JunB has been shown to cause a decrease in the size of the stem cell compartment in mice and targeted deletion of JunB in HSCs led to an increase in the size of the long-term (LT) HSC and granulocyte monocyte progenitor (GMP) compartments. Furthermore, these mice developed a myeloproliferative disorder with some progressing to develop acute leukemia.47 In this study, JunB was also shown to regulate LT-HSC self renewal, and its loss was associated with an increase in proliferation of the HSC compartment and a decrease in apoptosis of HSCs. JunB loss has also been associated with leukemic self-renewal in AML.48 Using a murine model of AML induced by a graded reduction of the PU.1 myeloid regulatory transcription factor, Rosenbauer, Tenen and colleagues demonstrated that JunB and the related factor c-Jun were critical target genes, in turn downregulated by the reduction in PU.1. In addition, the | 178 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 association between low PU.1 and low JunB expression was confirmed from expression analysis of human AML samples, and was particularly marked when expression within the LSC compartment (CD34+/CD38–) was analysed. Lastly, restoration of JunB expression in murine leukemic PU.1 knockdown cells inhibited their clonogenic efficiency in vitro and their ability to transfer leukemia in vivo.48 Overall, these data demonstrate that modulation of the JunB transcriptional pathway may reduce selfrenewal in leukemia stem cells, and suggest this pathway as a therapeutic target. Quiescence and cell cycle entry are very tightly controlled in normal HSC to help self-renewal and prevent depletion of the stem cell pool. The PI3KAKT-FoxO pathway, mediated through effectors such as p21, seems to be central to this cell cycle control.29,30,49,50 Two recent reports demonstrate that constitutive activation of the PI3K pathway through targeted deletion of PTEN, the major lipid phosphatase attenuating PI3K signaling, results both in HSC depletion and in the development of acute leukemia in mice.29,30 Following deletion of PTEN, HSC numbers were seen to briefly rise, with increased entry into cell cycle. However, this was followed by a marked reduction in HSC number over time. This quantitative decrease was also accompanied by qualitative defects in stem cell and hematopoietic reconstitution, as confirmed by competitive and non-competitive bone marrow transplant assays. The mice also demonstrated an initial myeloproliferative phase that was quickly followed by acute leukemia of both lymphoid and myeloid phenotype, that was transplantable to secondary recipients.29,30 Deregulation of the mTOR pathway downstream of AKT is a prominent consequence of PTEN inactivation. Inhibition of this pathway is possible and the authors used the inhibitor, rapamycin, to examine the effects on both leukemogenesis and normal HSC self-renewal. Not only did rapamycin restore normal cell cycle characteristics, normal number and reconstitution function to PTEN-/- HSC, its administration to PTEN-/- mice prevented the development of leukemia. In adoptive transfer experiments, rapamycin also depleted the number of leukemia-initiating cells and, importantly, rapamycin was shown to prolong survival even when administered to mice with established leukemia. This important study therefore demonstrates in a mouse model that drugs may target selfrenewal/quiescence in leukemia stem cells without eliminating normal bystander HSC. Furthermore, it identifies genes which promote stem cell quiescence as amenable targets, because although normal stem cells require quiescence as a defense mechanism, adopting quiescence may be detrimental to LSCs. The PI3K pathway is one of the major signaling pathways downstream of oncogenic tyrosine kinases, and as such, is constitutively activated in human AML.51 mTOR inhibitors such as rapamyin (sirolimus) and its derivatives (temsirolimus, CCI-779, everolimus, RAD001 and AP23573) have already been demonstrated to have efficacy against AML cell lines and patient samples.52,53 These studies not only showed a decreased survival of AML blasts, due partly to induction of apoptosis,52 but also demonstrated a loss of clonogenic potential of AML blasts whilst sparing normal hematopoietic progenitors.53 This supports the suggestion made above in mice that rapamycin targets LSC self-renewal whilst sparing self-renewal of normal HSC. mTOR inhibitors have also been shown to synergise with Ara-C and Etoposide, with the latter combination dramatically decreasing engraftment of AML in NOD-SCID mice.52,54 Furthermore, rapamycin induced clinically significant responses in 4 out of 9 patients with poor risk AML.49 Overall, these data suggest that mTOR inhibitors may target both self-renewal and survival mechanisms in AML. Further phase I and II studies of mTOR inhibitors, alone and in combination with standard chemotherapy regimens, are currently underway to test these hypotheses.55,56 Targeting apoptosis in LSCs The NF-κB pathway has been shown to be activated in cancer, where it mediates growth and proliferation signals, evasion of apoptosis and tumor invasion and metastasis. Furthermore, inhibition of NFκB induces apoptosis in several malignant cell types.57 NF-κB was first demonstrated by Jordan and colleagues to be constitutively active in primary AML CD34+ cells, but not normal CD34+ cells. They further demonstrated that the proteosome inhibitor MG-132 could downregulate NF-κB activity in primary AML cells and led to apoptosis in CD34+ AML cells but not in normal CD34+ cells.58 This work was subsequently extended to demonstrate that pretreatment of AML cells with MG-132 and the anthracycline idarubicin selectively prevented the engraftment of AML in NOD/SCID mice, but did not affect the ability of normal marrow to engraft.59 Use of a dominant negative inhibitor of NF-κB (IκB) also downregulated NF-κB activity and induced a p53-regulated apoptotic response in primary AML cells, confirming the importance of the NF-κB pathway in this response. The NF-κB pathway has also more recently been targeted using parthenolide. Parthenolide (PTL) is a sesquiterpine lactone and is the major active component in feverfew. This is herbal medicine which has been used to treat headache and rheumatoid arthritis for centuries and has recently been demonstrated to have antitumour activity.60 Jordan and colleagues Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 179 | 12th Congress of the European Hematology Association have demonstrated that PTL preferentially targets the LSC compartment, both in vitro and in vivo, while sparing the normal HSC compartment. This selection process was not demonstrated when AML and normal CD34+ cells were treated with Ara-C. PTL was also demonstrated to inhibit NF-κB, and the level of inhibition of NF-κB and activation of p53 correlated with the induction of apoptosis.60 PTL also increased the levels of reactive oxygen species (ROS) in AML cells and the induction of apoptosis also seemed to be dependent upon the oxidative changes, as pretreatment of AML cells with the antioxidant N-acetylcysteine (NAC) completely abolished the effects of PTL. These data suggest that PTL acts selectively through a number of pathways, through inhibition of NF-κB, but also through activation of p53 and the induction of ROS. Importantly, this study also suggests that AML LSC may be more sensitive to alterations in their oxidative environment than normal HSC, presenting another potential pathway for therapeutic targeting. Unfortunately, the solubility of PTL prevents its clinical use but chemical modification to improve this are underway. Other inhibitors of IκB kinase (which phosphorylates and targets IκB for destruction, and whose inhibition would in turn decrease NF-κB activity) are also entering clinical trials.61 Directing differentiation in LSC Another important characteristic of cancer is the failure of normal differentiation. A differentiation block of varying degrees is a main feature of AML. The paradigm of differentiation therapy has been demonstrated in acute promyelocytic leukemia (APML), associated with certain rearrangements of the retinoic acid receptor alpha (RARA), where pharmacological doses of all-trans retinoic acid (ATRA) cancel the differentiation block and induces myeloid differentiation. It is not known if this specifically targets the LSC or a later leukemic progenitor. However, it is known that ATRA treatment needs to be combined with standard chemotherapy or arsenic trioxide to maximise the likelihood of cure. This suggests that at least some LSCs fail to differentiate when exposed to ATRA. The differentiation block seen in AML probably reflects repression of gene programmes associated with differentiation, either through loss of function mutations to myeloid master-regulators such as PU.1 and C/EBPα, or through repression of these masterregulators by leukemia-associated fusion oncogenes such as AML1-ETO and PML-RARA.62,63 These fusion oncogenes are known to involve corepressors and histone deacetylases in an inhibitory complex leading to gene silencing. This suggests that histone deacetylation inhibitors (HDACi) may cancel these properties, restoring gene expression. Some degree of success has been shown in the treatment of cutaneous T-cell lymphomas, however, there are concerns over the specificity of these agents64 and clinical trials continue. A future alternative might be to re-establish the PU.1 and C/EBPα programmes through direct peptidomimetics or peptidomimetics of downstream effectors such as c-Jun.48 A more likely alternative would be through small molecular inhibition of, or systemic siRNA delivery against leukemia-associated fusion proteins. However this is not yet technically possible, but advances suggest that in the future this may be an option for certain transcription factors.65,66 Differentiation is a complex process driven by specific transcriptional programmes started through cell intrinsic cues in stem and progenitor cells and also via external stimuli from the stem cell niche. A mediator of this stem cell/niche interaction, the CD44 surface antigen, is another potential target for differentiation of LSCs. CD44 is a glycoprotein that functions as a cell adhesion molecule through interaction with matrix ligands such as hyaluron. Ligation of CD44 in vitro was shown to restore differentiation to AML primary cells from subtypes M1-M567 and a recent report by Dick and colleagues demonstrates that targeting CD44 with an activating monoclonal antibody (H90) led to eradication of human AML LSCs in an in vivo NOD/SCID transplantation assay.68 This effect appeared to be due to a combination of induction of differentiation, with concomitant loss of SL-IC (LSC) activity, and a decreased SLIC homing efficiency to the stem cell niche. These effects were considerably more apparent for the LSC compartment than the normal HSC compartment. These findings are also confirmed by a simultaneous report of the requirement for CD44 in a mouse model of CML. This demonstrated that the BCRABL+ LSC compartment was dependent upon CD44 to a much greater degree for homing and engraftment than the normal HSC compartment.69 Overall, these data suggest that in vivo disruption of the CD44-mediated LSC/niche interaction may induce commitment at the expense of self-renewal. Another important conclusion is that the leukemic process does not totally annul niche requirements of the LSC. This could lead to a completely new therapeutic approach, that of targeting the LSC/niche interaction. Further studies defining the biology of this interaction and how it differs from normal HSC/niche requirements may also lead to future therapeutic benefit. Conclusions There is much room for improvement in the current treatment of acute myeloid leukemia. Recent | 180 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 studies have demonstrated the importance of leukemia stem cells in treatment failure associated with AML and have looked at the biology of these rare and elusive cells. Importantly, these new studies suggest that there are some identifiable differences between normal HSCs and LSCs. These could be used in therapy. These studies also suggest that some existing therapeutic agents may already have selective activity against the LSC compartment. In particular, it will be important in future studies to understand more about the biology of LSCs and better define the differences from normal HSC biology. This should identify potential molecular targets for prospective preclinical and clinical evaluation. The existence and critical importance of LSC also suggests that we need to assess newer therapeutics in a different way. Until now, these response assays have mainly measured proliferation as an end point and may therefore have missed activities against the LSC compartment. As detailed above, in vitro and in vivo assays do exist to measure LSC activity. Using these assays will identify agents to test against the LSC compartment in vivo in clinical trials. The availability of such agents, probably used in combination with current AML therapy to target the total tumour load, should make an important impact on the outlook and survival of patients with AML. References 1. Huntly BJ, Gilliland DG. Leukemia stem cells and the evolution of cancer-stem-cell research. Nat Rev Cancer 2005;5:31121. 2. Lapidot T, Sirard C, Vormoor J, Murdoch B, Hoang T, CaceresCortes J, et al. A cell initiating human acute myeloid leukemia after transplantation into SCID mice. Nature 1994;367:645-8. 3. Bonnet D, Dick JE. Human acute myeloid leukemia is organized as a hierarchy that originates from a primitive hematopoietic cell. Nat Med 1997;3:730-7. 4. Castor A, Nilsson L, Astrand-Grundstrom I, Buitenhuis M, Ramirez C, Anderson K, et al. Distinct patterns of hematopoietic stem cell involvement in acute lymphoblastic leukemia. Nat Med 2005;11:630-7. 5. Al-Hajj M, Wicha M, Benito-Hernandez A, Morrison S, Clarke M. Prospective identification of tumorigenic breast cancer cells. Proceedings of the National Academy of Sciences of the United States of America 2003;100:3983-8. 6. Singh SK, Hawkins C, Clarke ID, Squire JA, Bayani J, Hide T, et al. Identification of human brain tumour initiating cells. Nature 2004;432:396-401. 7. Collins AT, Berry PA, Hyde C, Stower MJ, Maitland NJ. Prospective identification of tumorigenic prostate cancer stem cells. Cancer Res 2005;65:10946-51. 8. O'Brien CA, Pollett A, Gallinger S, Dick JE. A human colon cancer cell capable of initiating tumour growth in immunodeficient mice. Nature 2007;445:106-10. 9. Ricci-Vitiani L, Lombardi DG, Pilozzi E, Biffoni M, Todaro M, Peschle C, et al. Identification and expansion of human coloncancer-initiating cells. Nature 2007;445:111-5. 10. Stone RM, O'Donnell MR, Sekeres MA. Acute myeloid leukemia. Hematology Am Soc Hematol Educ Program 2004: 98-117. 11. Estey E, Dohner H. Acute myeloid leukemia. Lancet 2006; 368:1894-907. 12. Tallman MS. New agents for the treatment of acute myeloid leukemia. Best Pract Res Clin hematol 2006;19:311-20. 13. Coulombel L. Identification of hematopoietic stem/progenitor cells: strength and drawbacks of functional assays. Oncogene. 2004;23:7210-22. 14. Blair A, Hogge DE, Ailles LE, Lansdorp PM, Sutherland HJ. Lack of expression of Thy-1 (CD90) on acute myeloid leukemia cells with long-term proliferative ability in vitro and in vivo. Blood 1997;89:3104-12. 15. Blair A, Hogge DE, Sutherland HJ. Most acute myeloid leukemia progenitor cells with long-term proliferative ability in vitro and in vivo have the phenotype CD34+/CD71–/HLADR Blood 1998;92:4325-35. 16. Jordan CT, Upchurch D, Szilvassy SJ, Guzman ML, Howard DS, et al. The interleukin-3 receptor alpha chain is a unique marker for human acute myelogenous leukemia stem cells. Leukemia 2000;14:1777-84. 17. Blair A, Sutherland HJ. Primitive acute myeloid leukemia cells with long-term proliferative ability in vitro and in vivo lack surface expression of c-kit (CD117). Exp Hematol 2000; 28:660-71. 18. Taussig DC, Pearce DJ, Simpson C, Rohatiner AZ, Lister TA, Kelly G, et al. Hematopoietic stem cells express multiple myeloid markers: implications for the origin and targeted therapy of acute myeloid leukemia. Blood 2005;106:4086-92. 19. Abutalib SA, Tallman MS. Monoclonal antibodies for the treatment of acute myeloid leukemia. Curr Pharm Biotechnol 2006;7:343-69. 20. Feuring-Buske M, Frankel AE, Alexander RL, Gerhard B, Hogge DE. A diphtheria toxin-interleukin 3 fusion protein is cytotoxic to primitive acute myeloid leukemia progenitors but spares normal progenitors. Cancer Res 2002;62:1730-6. 21. Cohen KA, Liu TF, Cline JM, Wagner JD, Hall PD, Frankel AE. Toxicology and pharmacokinetics of DT388IL3, a fusion toxin consisting of a truncated diphtheria toxin (DT388) linked to human interleukin 3 (IL3), in cynomolgus monkeys. Leuk Lymphoma 2004;45:1647-56. 22. Frankel AE, Weir MA, Hall PD, Hogge DE, Rizzieri DA. Diptheria toxin-interleukin 3 fusion protein therapy of patients with elderly or relapsed/refractory acute myeloid leukemia (AML)[abstract]. J Clin Oncol 2006;24:6569. 23. Hanahan D, Weinberg R. The hallmarks of cancer. Cell 2000;100:57-70. 24. Owens BM, Hawley RG. HOX and non-HOX homeobox genes in leukemic hematopoiesis. Stem Cells 2002;20:364-379. 25. Abate-Shen C. Deregulated homeobox gene expression in cancer: cause or consequence? Nat Rev Cancer 002;2:777-85. 26. Simon M, Grandage VL, Linch DC, Khwaja A. Constitutive activation of the Wnt/beta-catenin signalling pathway in acute myeloid leukemia. Oncogene. 2005;24:2410-20. 27. Jamieson CH, Ailles LE, Dylla SJ, Muijtjens M, Jones C, Zehnder JL, et al. Granulocyte-macrophage progenitors as candidate leukemic stem cells in blast-crisis CML. N Engl J Med 2004;351:657-67. 28. Weng AP, Ferrando AA, Lee W, Morris JPT, Silverman LB, Sanchez-Irizarry C, et al. Activating mutations of NOTCH1 in human T cell acute lymphoblastic leukemia. Science 2004; 306:269-71. 29. Yilmaz OH, Valdez R, Theisen BK, Guo W, Ferguson DO, Wu H, Morrison SJ. Pten dependence distinguishes hematopoietic stem cells from leukemia-initiating cells. Nature 2006; 441:47582. 30. Zhang J, Grindley JC, Yin T, Jayasinghe S, He XC, Ross JT, et al. PTEN maintains hematopoietic stem cells and acts in lineage choice and leukemia prevention. Nature 2006;441:518-22. 31. Taipale J, Beachy PA. The Hedgehog and Wnt signalling pathways in cancer. Nature 2001;411:349-54. 32. Valk-Lingbeek ME, Bruggeman SW, van Lohuizen M. Stem cells and cancer; the polycomb connection. Cell 2004;118:40918. 33. Lessard J, Sauvageau G. Bmi-1 determines the proliferative capacity of normal and leukemic stem cells. Nature 2003; 423:255-60. 34. Reya T, Duncan AW, Ailles L, Domen J, Scherer DC, Willert K, et al. A role for Wnt signalling in self-renewal of hematopoietic stem cells. Nature 2003;423:409-14. 35. Antonchuk J, Sauvageau G, Humphries RK. HOXB4-induced expansion of adult hematopoietic stem cells ex vivo. Cell 2002;109:39-45. 36. Varnum-Finney B, Xu L, Brashem-Stein C, Nourigat C, Flowers D, Bakkour S, et al. Pluripotent, cytokine-dependent, hematopoietic stem cells are immortalized by constitutive Notch1 signaling. Nat Med 2000;6:1278-81. 37. Bhardwaj G, Murdoch B, Wu D, Baker DP, Williams KP, Chadwick K, et al. Sonic hedgehog induces the proliferation of primitive human hematopoietic cells via BMP regulation. Nat Immunol 2001;2:172-80. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 181 | 12th Congress of the European Hematology Association 38. Park I, Qian D, Kiel M, Becker M, Pihalja M, Weissman I, et al. Bmi-1 is required for maintenance of adult self-renewing hematopoietic stem cells. Nature 2003;423:302-5. 39. Cobas M, Wilson A, Ernst B, Mancini SJ, MacDonald HR, Kemler R, et al. Beta-catenin is dispensable for hematopoiesis and lymphopoiesis. J Exp Med 2004;199:221-9. 40. Kirstetter P, Anderson K, Porse BT, Jacobsen SE, Nerlov C. Activation of the canonical Wnt pathway leads to loss of hematopoietic stem cell repopulation and multilineage differentiation block. Nat Immunol 2006;7:1048-56. 41. Scheller M, Huelsken J, Rosenbauer F, Taketo MM, Birchmeier W, Tenen DG, et al. Hematopoietic stem cell and multilineage defects generated by constitutive beta-catenin activation. Nat Immunol 2006;7:1037-47. 42. Trowbridge JJ, Moon RT, Bhatia M. Hematopoietic stem cell biology: too much of a Wnt thing. Nat Immunol 2006;7:10213. 43. Huntly BJ, Shigematsu H, Deguchi K, Lee BH, Mizuno S, Duclos N, et al. MOZ-TIF2, but not BCR-ABL, confers properties of leukemic stem cells to committed murine hematopoietic progenitors. Cancer Cell 2004;6:587-96. 44. Cozzio A, Passegue E, Ayton PM, Karsunky H, Cleary ML, Weissman IL. Similar MLL-associated leukemias arising from self-renewing stem cells and short-lived myeloid progenitors. Genes Dev 2003;17:3029-35. 45. Krivtsov AV, Twomey D, Feng Z, Stubbs MC, Wang Y, Faber J, et al. Transformation from committed progenitor to leukemia stem cell initiated by MLL-AF9. Nature 2006; 442:818-22. 46. Passegue E, Jochum W, Schorpp-Kistner M, Mohle-Steinlein U, Wagner EF. Chronic myeloid leukemia with increased granulocyte progenitors in mice lacking junB expression in the myeloid lineage. Cell 2001;104:21-32. 47. Passegue E, Wagner EF, Weissman IL. JunB deficiency leads to a myeloproliferative disorder arising from hematopoietic stem cells. Cell 2004;119:431-43. 48. Steidl U, Rosenbauer F, Verhaak RG, Gu X, Ebralidze A, Otu HH, K et al. Essential role of Jun family transcription factors in PU.1 knockdown-induced leukemic stem cells. Nat Genet 2006; 38:1269-77. 49. Tothova Z, Kollipara R, Huntly BJ, Lee BH, Castrillon DH, Cullen DE, et al. FoxOs are critical mediators of hematopoietic stem cell resistance to physiologic oxidative stress. Cell 2007;128:325-39. 50. Cheng T, Rodrigues N, Shen H, Yang Y, Dombkowski D, Sykes M, et al. Hematopoietic stem cell quiescence maintained by p21cip1/waf1. Science 2000;287:1804-8. 51. Martelli AM, Nyakern M, Tabellini G, Bortul R, Tazzari PL, Evangelisti C, et al. Phosphoinositide 3-kinase/Akt signaling pathway and its therapeutical implications for human acute myeloid leukemia. Leukemia 2006;20:911-28. 52. Xu Q, Simpson SE, Scialla TJ, Bagg A, Carroll M. Survival of acute myeloid leukemia cells requires PI3 kinase activation. Blood 2003;102:972-80. 53. Recher C, Beyne-Rauzy O, Demur C, Chicanne G, Dos Santos C, Mas VM, et al. Antileukemic activity of rapamycin in acute myeloid leukemia. Blood 2005;105:2527-34. 54. Xu Q, Thompson JE, Carroll M. mTOR regulates cell survival after etoposide treatment in primary AML cells. Blood 2005; 106:4261-8. 55. Luger SM, Perl A, Kemner A, Stadtmauer E, Porter D, Schuster SJ, et al. A phase I dose escalation study of the mTOR inhibitor Sirolimus and MEC chemotherapy targeting signal transduction in leukemic stem cells for AML [abstract]. Blood 2006;108:52a. 56. Feldman E, Giles F, Roboz G, Yee K, Curcio T, Rivera V, et al. A phase 2 clinical trial of AP23573, an mTOR inhibitor, in patients with relapsed or refractory hematologic malignancies [abstract]. J Clin Oncol 2005;23:6631. 57. Basseres DS, Baldwin AS. Nuclear factor-kappaB and inhibitor of kappaB kinase pathways in oncogenic initiation and progression. Oncogene 2006;25:6817-30. 58. Guzman ML, Neering SJ, Upchurch D, Grimes B, Howard DS, Rizzieri DA, et al. Nuclear factor-kappaB is constitutively activated in primitive human acute myelogenous leukemia cells. Blood 2001;98:2301-7. 59. Guzman ML, Swiderski CF, Howard DS, Grimes BA, Rossi RM, Szilvassy SJ, et al. Preferential induction of apoptosis for primary human leukemic stem cells. Proc Natl Acad Sci USA 2002;99:16220-5. 60. Guzman ML, Rossi RM, Karnischky L, Li X, Peterson DR, Howard DS, Jordan CT. The sesquiterpene lactone parthenolide induces apoptosis of human acute myelogenous leukemia stem and progenitor cells. Blood 2005;105:4163-9. 61. Frelin C, Imbert V, Griessinger E, Peyron AC, Rochet N, Philip P, et al. Targeting NF-kappaB activation via pharmacologic inhibition of IKK2-induced apoptosis of human acute myeloid leukemia cells. Blood 2005;105:804-11. 62. Tenen DG. Disruption of differentiation in human cancer: AML shows the way. Nat Rev Cancer 2003;3:89-101. 63. Rosenbauer F, Tenen DG. Transcription factors in myeloid development: balancing differentiation with transformation. Nat Rev Immunol 2007;7:105-17. 64. Karagiannis TC, El-Osta A. Will broad-spectrum histone deacetylase inhibitors be superseded by more specific compounds? Leukemia 2007;21:61-5. 65. Zimmermann TS, Lee AC, Akinc A, Bramlage B, Bumcrot D, Fedoruk MN, et al. RNAi-mediated gene silencing in nonhuman primates. Nature 2006;441:111-4. 66. Best JL, Amezcua CA, Mayr B, Flechner L, Murawsky CM, Emerson B, et al. Identification of small-molecule antagonists that inhibit an activator: coactivator interaction. Proc Natl Acad Sci USA 2004;101:17622-7. 67. Charrad RS, Li Y, Delpech B, Balitrand N, Clay D, Jasmin C, et al. Ligation of the CD44 adhesion molecule reverses blockage of differentiation in human acute myeloid leukemia. Nat Med 1999;5:669-76. 68. Jin L, Hope KJ, Zhai Q, Smadja-Joffe F, Dick JE. Targeting of CD44 eradicates human acute myeloid leukemic stem cells. Nat Med 2006;12:1167-74. 69. Krause DS, Lazarides K, von Andrian UH, Van Etten RA. Requirement for CD44 in homing and engraftment of BCRABL-expressing leukemic stem cells. Nat Med 2006;12:117580. 70. Cully M, You H, Levine AJ, Mak TW. Beyond PTEN mutations: the PI3K pathway as an integrator of multiple inputs during tumorigenesis. Nat Rev Cancer 2006;6:184-92. | 182 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Acute Myeloid Leukemia Clinical use of molecular markers in adult acute myeloid leukemia K. Mrózek P. Paschka G. Marcucci S.P. Whitman C.D. Bloomfield Division of Hematology and Oncology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:183-192 A B S T R A C T It is generally accepted that specimens from all newly diagnosed patients with acute myeloid leukemia (AML) should be subjected to cytogenetic analysis. The results are then used to determine prognosis and often therapeutic approaches. Increasingly, testing for submicroscopic molecular genetic alterations is also performed. Several gene mutations and changes in gene expression have been shown to represent prognostic factors and/or potential targets for therapy in patients categorized in specific cytogenetic subsets. Until now, these molecular genetic alterations have been most important to determine prognosis of patients with core-binding AML, i.e., those having either t(8;21)(q22q;22) or inv(16)(p13q22)/t(16;16)(p13;q22), and of patients with a normal karyotype, the single largest cytogenetic group with approximately 45% of adults with AML. Gene-expression profiling has also been shown to be a useful tool for the classification and, to some extent, prognosis of AML. In this article we provide a brief overview of the most important molecular genetic alterations with established or potential clinical significance in adult AML. ytogenetic and molecular genetic studies have revealed that acute myeloid leukemia (AML) is a genetically heterogeneous disease.1-3 More than 200 structural and numerical aberrations have been recognized as recurring in AML.1 Cytogenetic findings at diagnosis have been among the most important independent prognostic factors for complete remission (CR), relapse risk and overall survival.4-10 However, there is a continuous increase in the amount of data on the prognostic role of molecular genetic alterations within cytogenetically defined groups of AML patients. In this article, we will briefly summarize recent publications about those molecular genetic alterations that contribute to prognosis of AML patients with specific cytogenetic findings such as t(8;21)(q22q;22) and inv(16) (p13q22)/t(16;16)(p13;q22), chromosome aberrations characteristic of corebinding factor (CBF) AML,11 and patients with a normal karyotype (Table 1). Together these cytogenetic groups account for about 60% of adults with AML under the age of 60. C Mutations of KIT as molecular genetic prognostic factors in core-binding factor (CBF) AML with t(8;21) and inv(16)/t(16;16) Among adults with de novo AML, t(8;21) and inv(16)/t(16;16) are found in 7% and 8% of patients respectively.7 At the molecular level, both chromosome aberrations lead to rearrangements involving genes encoding different subunits of CBF,12-14 This is a transcription factor involved in the regulation of normal hematopoiesis.15 In t(8;21), the RUNX1 (AML1) gene encoding subunit α of CBF is fused to the RUNX1T1(ETO) gene,12 and in inv(16)/ t(16;16) the CBFB gene, encoding subunit β of CBF, is fused to the MYH11 gene.13 Protein products of the CBF fusion genes act as dominant negative inhibitors of normal hematopoiesis and contribute to leukemogenesis.15-17 The introduction of higher doses of cytarabine (HiDAC) as consolidation therapy has considerably improved the outcome for AML patients with t(8;21) and inv(16)/t(16;16).18 It appears that HiDAC is more effective in the setting of repetitive cycles than in one cycle.19,20 Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 183 | 12th Congress of the European Hematology Association Table 1. Clinically relevant genes mutated and/or overexpressed in CBF AML and CN AML. Gene symbol Gene name Chromosome location KIT v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog FLT3 fms-related tyrosine kinase 3 13q12 MLL myeloid/lymphoid or mixed-lineage leukemia (trithorax homolog, Drosophila) 11q23 CEBPA CCAAT/enhancer binding protein (C/EBP), alpha NPM1 nucleophosmin (nucleolar phosphoprotein B23, numatrin) 5q35 WT1 Wilms tumor 1 11p13 BAALC brain and acute leukemia gene, cytoplasmic 8q22.3 ERG v-ets erythroblastosis virus E26 oncogene like (avian) 21q22.3 MN1 meningioma (disrupted in balanced translocation) 1 4q11-q12 19q13.1 22q11 Because of the involvement of subunits of CBF at the molecular level and favorable response to treatment, patients with t(8;21) are often combined with those with inv(16)/t(16;16) into one favorable-risk prognostic category of AML. However, despite similarities, patients with t(8;21) differ from those with inv(16)/t(16;16) in many pretreatment features and clinical outcome.21-23 The relatively high CR rates of 85% to 89% are similar in both cytogenetic groups.21-23 But lower CR probability was associated with hepatomegaly only in inv(16)/t(16;16) patients, while higher BM blasts and, unexpectedly, nonwhite race were associated only in t(8;21) patients.22 There was no significant difference in either relapse risk or overall survival (OS) did not differ significantly between t(8;21) and inv(16)/t(16;16) groups in univariable analyses.21-23 However, the OS of patients with t(8;21) was significantly shorter than the OS of those with inv(16)/t(16;16) after adjusting for age, log[WBC], and log[platelets].22 This seems to be related to a different response to salvage treatment. Patients with t(8;21) have had a significantly shorter survival after relapse than inv(16)/t(16;16) patients in three large, independent studies.21-23 Also, two studies have shown that the presence of a secondary +22 was a favorable prognostic factor for relapse risk in inv(16)/t(16;16) patients.21,22 By contrast, a possible interaction between secondary chromosome aberrations and race was observed in t(8;21) patients in one study.22 Nonwhite patients with secondary aberrations other than del(9q) had shorter OS than patients with t(8;21) as a single abnormality or those with a secondary del(9q). By contrast, OS of white patients with t(8;21) was not influenced by secondary aberrations.22 Since approximately 50% of all CBF AML patients are still not cured with contemporary chemotherapy,22 it is important to identify patients who are likely to fail current standard therapy early, if possible at diagnosis. They can then be treated with novel investigational or more aggressive therapies, e.g., stem cell transplantation (SCT). Recent studies have shown that mutations in the KIT gene, which encodes a member of the type III receptor tyrosine kinase (RTK) family,24 may be the first molecular prognostic marker in CBF AML predicting a less favorable outcome (Table 2). Importantly, the abnormal KIT protein encoded by the mutated KIT gene represents a potential therapeutic target. KIT mutations have been reported in 20-45% of CBF AML cases,25-27 although some studies report a lower frequency.28-29 This variable incidence of KIT mutations can be partly explained by different sizes of patient cohorts studied, a variety of techniques used to detect mutations, and differences in regions of the KIT gene covered by mutational analyses. The existence of potential geographic and ethnic variation in the frequency of KIT mutations still hasn’t been evaluated. In CBF AML, KIT mutations mainly cluster within the activation loop in the kinase domain encoded by sequences of exon 17 and in exon 8 that encodes an extracellular part of the receptor. But mutations in other regions have also been reported.26,30,31 The adverse prognostic significance of KIT mutations in patients with t(8;21) at diagnosis has been well documented. Different KIT mutations analyzed as one group and mutations in exon 17 have both been associated with inferior OS,26,28,29 eventfree survival (EFS),28,29 relapse incidence,26 relapsefree survival (RFS),29 and cumulative incidence of relapse (CIR).27 The prognostic impact of KIT mutations in AML with inv(16)/t(16;16) is less clear. In one study, KIT mutations in exon 8 increased the relapse rate, but not OS,25 but had no prognostic significance in two other smaller series.26,29 The most recent, study was performed on a relatively large group of inv(16) patients, all of whom were similarly treated on Cancer and Leukemia Group B protocols including higher cytarabine doses for consolidation.27 This study showed that the presence of any KIT mutation (involving both exon 8 and exon 17) led to a higher CIR. Notably, the difference in CIR was primarily caused by KIT mutations in exon 17.27 Patients with exon 17 mutations had more than 6 times a higher risk of relapse than those without KIT mutations. In multivariable analyses, KIT mutations, both those in exon 8 and exon 17, impacted negatively on OS after adjusting for sex.27 | 184 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 2. Molecular genetic alterations affecting clinical outcome of AML patients with core binding AML and cytogenetically normal AML. Cytogenetic group Molecular genetic alteration Frequency % Prognostic significance t(8;21)(q22;q22) Mutations of KIT 12-47 Patients with KIT mutations, especially those with mutations in exon 17 that encodes the activation loop in the kinase domain of KIT, have lower OS, EFS, RFS, relapse incidence and CIR compared with patients with wild-type KIT. inv(16)(p13q22)/ t(16;16)(p13;q22) Mutations of KIT 22-47 Patients with KIT mutations in exon 8 had worse RR than patients with wild-type KIT in one study. 25 Patients with KIT mutations in exon 17 had higher CIR, and OS after adjusting for sex in one study. 27 Normal karyotype Normal karyotype FLT3-ITD MLL-PTD 28-33 5-11 References 26-29 Two relatively small studies did not detect any prognostic impact of KIT mutations. 26,29 Patients with FLT3-ITD have significantly shorter CRD, DFS and OS than patients without FLT3-ITD. 52, 53, 57, 60 FLT3-ITD-positive patients with either no expression of a FLT3 wild-type allele or a high FLT3 mutant to FLT3 wild-type allele ratio have particularly poor prognosis. 51, 56 Patients with MLL-PTD have a significantly shorter remission duration than patients without MLL-PTD. No difference in DFS and OS between patients with and without 80-82 MLL-PTD undERGoing intensive treatment that included autologous SCT in one recent study. 84 Normal karyotype Mutations of CEBPA 15-19 Patients with CEBPA mutations have CRD and OS significantly longer than patients with the wild-type CEBPA gene. 60, 61, 87 Normal karyotype Mutations of NPM1 45-64 Patients with NPM1 mutations and no FLT3-ITD have significantly better CR rates, EFS, RFS, DFS, and OS than patients without NPM1 mutations and FLT3-ITD. NPM1 mutations do not seem to significantly affect poor prognosis of patients with FLT3-ITD. 55, 64, 92 Normal karyotype Mutations of WT1 10 Patients with WT1 mutations and FLT3-ITD fail to achieve a CR with standard induction chemotherapy Normal karyotype Overexpression of BAALC NA Patients with high expression of the BAALC gene have significantly worse CR rates and shorter DFS, EFS and OS than patients with low expression of the BAALC gene. Normal karyotype Overexpression of ERG NA Patients with high expression of the ERG gene in blood have significantly shorter OS and higher CIR than patients with low expression of the ERG gene. 100, 101 Normal karyotype Overexpression of MN1 NA Patients with high expression of the MN1 gene have significantly shorter OS and RFS and higher RR than patients with low expression of the MN1 gene. 105 94 60, 62, 97 OS, overall survival; EFS, event-free survival; RFS, relapse-free survival; CIR, cumulative incidence of relapse; RR, risk of relapse; CRD, complete remission duration; DFS, disease-free survival; SCT, stem cell transplantation; CR, complete remission; NA, not applicable. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 185 | 12th Congress of the European Hematology Association When activated by binding of its ligand, KIT RTK manages biologic processes like cell proliferation, differentiation, and survival. Importantly, KIT mutations lead to a constitutive activation of the receptor. This makes the abnormal KIT protein a potential target for TK inhibitors. However, it is essential to determine the exact type of KIT mutation in each patient because of the differential sensitivity to TK inhibitors. The first generation TK inhibitor imatinib shows in vitro activity against the variants of exon 8 mutations tested so far32-35 and against exon 17 mutations involving codon N822,31,36 but not against mutants involving codon D816.37 The latter mutations may be successfully targeted with other compounds, such as dasatinib,38 tandutinib (MLN518)39 and midostaurin (PKC412).28,35,40 In the future, testing for the presence of KIT mutations might guide therapeutic decisions at diagnosis,. Future clinical trials are necessary to investigate the usefulness of TK inhibitors as part of therapy administered to patients with CBF AML. Molecular markers in cytogenetically normal AML (CN-AML) Around 45% of adults with AML are cytogenetically normal (CN) at presentation.5-8 Their outcome is varied, with usually 20-40% of patients being longterm survivors.1,5-8,41 Consequently, considerable research is on-going to identify molecular markers that predict outcome and can serve as therapeutic targets. Using molecular genetic techniques, such as RT-PCR, global gene-expression profiling and/or direct sequencing, recurring molecular alterations of prognostic significance are increasingly being identified in CN-AML.42-44 These include gene mutations and overexpression of single genes (Tables 1 and 2). Recently, global gene-expression profiling has been undertaken to identify gene expression signatures associated with important molecular markers in CNAML patients.45-47 Mutations of the FLT3 gene The FLT3 gene encodes a membrane-bound protein of the class III RTK family. It is involved in regulation of proliferation, differentiation and apoptosis of hematopoietic cell progenitors.48 Internal tandem duplications (ITDs) of the FLT3 gene occur within the juxtamembrane domain (exons 14 and 15). The duplications can vary in length from 3 to over 400 nucleotides but always create an in-frame transcript. This is translated into a constitutively activated protein which, ligand-independent, promotes the aberrant proliferation and survival of leukemic blasts.49 FLT3-ITDs are detected in 28-33% of CN-AML patients.50-57 Further 5-14% of CN-AML patients carry missense mutations in exon 20 of FLT3, i.e., within the activation loop of the tyrosine kinase domain (FLT3-TKD).52,55-57 FLT3-TKDs also promote constitutive phosphorylation of the FLT3 protein and disruption of normal hematopoiesis. Point mutations in the juxtamembrane domain have also been reported, although not frequently.58,59 Multiple studies have demonstrated the impact of FLT3 mutations on the clinical outcome of CN-AML patients. FLT3-ITD has been found to be an independent prognostic factor for complete remission duration (CRD),60,61 CIR,62 and OS.60,62 This is particularly true for FLT3-ITD-positive patients whose blasts do not express the FLT3 wild-type (WT) allele,51 or have a FLT3 mutant/FLT3-WT allele ratio higher than the median value.56 The prognostic significance of the FLT3-TKD in the absence of the FLT3ITD remains controversial,52,63 as does the high-level overexpression of FLT3-WT. Optimum treatment for CN-AML patients with FLT3-ITD mutations is unclear. Both allogeneic SCT64 and autologous peripheral blood SCT in first CR65-67 have been reported to overcome the adverse prognostic effect of FLT3-ITD. However, other groups have found that the outcome of FLT3-ITD-positive patients is still worse than that of patients without FLT3-ITD, even in the setting of SCT.51,68 The constitutively activated FLT3 protein is an attractive therapeutic target for small-molecule TK inhibitors (e.g., midostaurin, lestaurtinib or tandutinib). As single agents these compounds have shown limited benefit in relapsed or refractory patients.69-73 However, inhibition of FLT3 autophosphorylation has been shown in responding patients.71-73 This has led to the current evaluation of these TK inhibitors in combination with chemotherapy in newly diagnosed patients. Other approaches currently in pre-clinical studies include FLT3 antibody therapy,74 which is predicted to also target overexpressed FLT3-WT, and inhibitors of downregulatory pathways such as 17allylamino-17-demethoxygeldanamycin (17-AAG), an inhibitor of the molecular chaperone heat shock protein 90.75-77 Mutations of the MLL gene The MLL gene is a homeotic regulator that encodes a nearly 430-kilodalton protein with histone lysine 4 methyltransferase activity. This protein regulates HOX gene expression during hematopoietic stem cell development.78 ALU-mediated recombination within the MLL gene generates a partial tandem duplication (PTD) spanning exons 5 through 11 or, less often, exons 5 through 12.79,80 MLL-PTD occurs in about 8% of adult de novo CN-AML,80-82 and it was the first molecular defect identified as an adverse prognostic factor in CN-AML.80,83 It has usually been reported to adversely impact CRD, but not OS.80-82 Recent data indicate improved outcome in younger adults treated | 186 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 with autologous SCT in first CR.84 The MLL-WT transcript is not expressed in AML blasts with the MLL-PTD.85 Transcriptional reactivation of the MLL-WT allele occurs in response to DNA methyltransferase (DNMT) and/or histone deacetylase (HDAC) inhibitors and is associated with enhanced sensitivity to cell death. Therefore, pharmacologic reversal of MLL-WT silencing by demethylating agents and histone deacetylase inhibitors should be investigated in CN-AML patients with the MLL-PTD.85 Mutations of the CEBPA gene The CEBPA gene encodes the C/EBPα protein, a member of the family of basic region leucine zipper (bZIP) transcription regulators involved in granulopoiesis.86 CEBPA mutations occur in 15-19% of CNAML.60,61,87 They confer significantly longer CRD and OS.60,61 Mutations of the NPM1 gene NPM1 encodes nucleophosmin, a nucleus-cytoplasm shuttling protein, involed in preventing nucleolar protein aggregation, regulation of ribosomal protein assembly and their nucleocytoplasmic transport, the initiation of centrosome duplication and the regulation of the p53 and Arf tumor-suppressor pathways.88 Its exact role in oncogenesis is controversial. Nucleophosmin is most prominent in the nucleus, but in patients with mutated NPM1, nucleophosmin shows cytoplasmic expression that may interfere with its normal functions.89 NPM1 mutations are found in 45-64% of CN-AML patients,55,64,90-92 and usually predict outcome only in the context of other markers. Coexistence of NPM1 mutations with MLL-PTD and CEBPA mutations is rare, but about 40% of NPM1 mutated patients are also FLT3-ITD-positive. The poor outcome of patients with FLT3-ITD is relatively unaffected by the presence or absence of NPM1 mutations. However, among patients without FLT3-ITD, those with NPM1 mutations have a significantly better response to induction therapy, disease-free survival (DFS), RFS, EFS and OS.55,64,92 Mutations of the WT1 gene WT1 encodes a zinc finger DNA-binding protein that continually shuttles between the nucleus and cytoplasm.93 Depending on cellular context, it can also be involved in transcriptional activation or repression. Its role in hematopoiesis and leukemogenesis is not well established, although it has been suggested that impairment of WT1 protein function could promote stem cell proliferation and induce a block in differentiation.94 In a recent study of CNAML, WT1 mutations were found in 7 out of 70 patients, and in 6 of them it coexisted with FLT3ITD. None of the 5 patients with WT1 mutations and FLT3-ITD treated with curative intent achieved a CR with standard induction chemotherapy.94 This agrees with results of an earlier study which was not restricted to CN-AML.95 Overexpression of the BAALC gene The BAALC gene encodes a protein with no homology to known proteins or functional domains. BAALC expression is mostly detected in hematopoietic precursors and neuroectoderm-derived tissues. High expression has been found in AML, acute lymphoblastic leukemia (ALL) and chronic myelogenous leukemia (CML) in blast crisis, but not in chronicphase CML or chronic lymphocytic leukemia (CLL).96 High expression of BAALC mRNA in CN-AML predicts adverse clinical outcome, including primary resistant disease, shorter DFS, OS, EFS and higher CIR.60,62,97 BAALC expression seems to be particularly useful in predicting outcome in CN-AML patients without FLT3-ITD and CEBPA mutations.60 It has been suggested that patients with high BAALC expression might benefit from allogeneic SCT.62 Overexpression of the ERG gene ERG is one of over 30 members of the ETS gene family. Most of these are down-stream nuclear targets of signal transduction pathways regulating and promoting cell differentiation, proliferation and tissue invasion.98,99 In CN-AML high ERG expression adversely impacts on CIR and EFS.100,101 For OS, an interaction between expression of ERG and BAALC has been observed. The adverse impact of high ERG expression on OS was only observed in patients with low BAALC expression.100,101 Overexpression of the MN1 gene The MN1 gene is a transcriptional co-activator,102 which was initially found rearranged in patients with meningioma with t(4;22)(p16;q11)103 and AML with t(12;22)(p13;q11~12).104 Mn1 null mice die shortly after birth as the result of a secondary cleft palate, suggesting that this gene plays an important role in normal bone development.102 Recently, overexpression of MN1 was found to be an independent unfavorable prognostic factor for OS and RFS in CNAML.105 These results await corroboration. Further evidence of these results must still be provided. Interrelation of molecular genetic markers It has been suggested that at least two somatic mutations with different consequences cooperate with each other to cause AML, since one mutation alone is not enough to transform a normal cell into a leukemic blast. Class I mutations are those in the sig- Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 187 | 12th Congress of the European Hematology Association nal transduction pathways (e.g., FLT3-ITD, FLT3TKD) that provide a proliferation stimulus, and class II mutations occur in genes encoding hematopoietic transcription factors (e.g., CEBPA or RUNX1) that impair cell differentiation.106,107 Because different mutations and changes in gene expression can occur in the same AML patient, it is important to evaluate the prognostic impact of the interaction between molecular alterations. For instance, NPM1 mutations predict better outcome mainly in the absence of FLT3-ITD,55,64,92 and the level of ERG expression identifies subsets of patients with differing prognoses within the subset of patients with NPM1 mutations but not FLT3-ITD.101 Clearly, prospective investigation of prognostic interactions among many genetic lesions is needed to design a clinically relevant prognostic classification of CNAML. Gene-expression profiling in AML Gene-expression profiling (GEP) has been shown to be a useful tool for the classification of leukemias. Golub et al.108 were the first to show that AML and ALL could be distinguished on the basis of characteristic gene-expression signatures. More recently, Haferlach et al.109 reported the ability of GEP to correctly identify cytogenetic subsets of AML with t(15;17), t(8;21), and inv(16), CLL, and pro-B-cell ALL (pro-B-ALL) with translocations involving 11q23 with 100% specificity and 100% sensitivity. A similar specificity (i.e. 99.7%) with a lower degree of sensitivity was achieved for the diagnosis of CN-AML, AML with translocations involving 11q23, AML with complex karyotype, pre-B- and T-ALL and CML.109 Within adult AML, distinct gene-expression patterns have been shown to be associated with specific cytogenetic and molecular alterations.45,46,109 Using unsupervised hierarchical analysis, two groups reported clustering to be driven by the presence of specific karyotypes (i.e., t(15;17), t(8;21), inv(16), normal cytogenetics)45,46 and genetic mutations (i.e. CEBPA) or abnormal oncogene expression (i.e. EVI1).46 Both unsupervised and supervised approaches were able to identify specific gene signatures associated with the aforementioned karyotypes and/or molecular aberrations (including also del(7q)/-7 and FLT3 mutations). But it is of interest that no distinct gene-expression patterns were found to identify patients with other molecular or cytogenetic rearrangements (e.g. MLL-PTD or trisomy 8) from those without these aberrations.45 Within specific cytogenetic categories, GEP has also helped identify novel biologic and prognostic subgroups. In the study by Bullinger et al.,45 CN-AML patients predominantly clustered into two distinct subclasses. The presence or absence of FLT3 muta- tions and the FAB morphologic subtypes (M1/M2 versus M4/M5) were different between the two. Patients in these subclasses had a significantly different OS. Prognostic significance of these clusters has recently been confirmed by Radmacher et al.47 in an independent set of patients, using a different microarray platform. Cluster analysis confirmed the prognostic impact of the Bullinger gene-expression signature for OS and DFS. Also, Radmacher et al.47 developed a class prediction algorithm that identified a signature-based classifier for outcome prediction. Subgroups of patients with significantly different OS and DFS were identified by this outcome classifier which seemed strongly associated with the FLT3ITD. However, the classifier for dichotomized outcome classes had only modest predictive accuracy, with OS and DFS of about 60% of patients being accurately predicted. Furthermore, although the classifier showed some ability to identify a subset of patients with poor outcome among patients without FLT3-ITD,47 other classifiers which can more precisely predict outcome of CN-AML patients are needed. Although in a recent study of pediatric patients,110 commonalities between t(8;21) and inv(16) geneexpression signatures were found, GEP has been repeatedly shown to accurately identify these two cytogenetic subgroups in adult patients.45,46 Within each cytogenetic group of adult patients distinct molecular subgroups were identified45,46 whose biologic and prognostic significance is under evaluation. Similarly, although distinct gene-expression signatures could identify patients with FLT3 or NPM1 mutations from those carrying the corresponding WT alleles,45,111 these patients appear to segregate in several clusters. This perhaps reflects the presence of these genomic abnormalities in different cytogenetic groups and/or the overlapping of these with other molecular markers in AML.45,46,112 Gene-expression profiling seems to be useful in AML classification. But this approach also has limitations. Several studies have shown that the differentiation stage of the lineage, reflected by the FAB classification, might direct the unsupervised clustering, which may prevent clear analyses.113 Furthermore, inconsistencies between data obtained using different microarray platforms have been detected.113,114 Finally, at least in CN-AML, only a moderate predictive accuracy for outcome prediction has been reported.47 However, by taking a general view of the molecular heterogeneity of AML, gene-expression profiling may help to examine pathogenetic mechanisms and therefore provide new understanding of tumor biology and identify novel therapeutic targets. Geneexpression profiling by itself will probably nor be enough to show the whole pathobiologic nature of AML. The integration with other genomic technolo- | 188 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 gies, such as high-throughput mutational analyses and proteomic approaches, will be necessary to take on this important challenge.113 11. Conclusions Several molecular markers with prognostic significance within particular cytogenetic groups of AML have been and continue to be identified. These molecular markers will probably guide future therapies both as prognostic factors and targets for specific therapeutic intervention. It is, however, important to understand complex interactions among various mutations and changes in gene expression. Studies investigating all known prognostic molecular alterations concurrently to determine their relative impact on patients’ prognosis are ongoing, especially in CNAML. It is hoped that cytogenetic and molecular genetic analyses will allow accurate prediction of the response to therapy and the tailoring of treatment to specific genetic lesions acquired by the leukemic blasts, and that this will result in an improved clinical outcome for AML patients. Acknowledgements Supported in part by National Cancer Institute, Bethesda, Maryland grants CA77658, CA101140 and CA16058, and the Coleman Leukemia Research Foundation. 12. 13. 14. 15. 16. 17. 18. 19. References 1. Mrózek K, Heinonen K Bloomfield CD. Clinical importance of cytogenetics in acute myeloid leukaemia. Best Pract Res Clin Haematol 2001;14:19-47. 2. Frohling S, Scholl C, Gilliland DG, Levine RL. Genetics of myeloid malignancies: pathogenetic and clinical implications. J Clin Oncol 2005;23:6285-95. 3. Estey E, Döhner H. Acute myeloid leukaemia. Lancet 2006;368;1894-907. 4. Bloomfield CD, Goldman A, Hossfeld D, de la Chapelle A. Fourth International Workshop on Chromosomes in Leukemia, 1982: clinical significance of chromosomal abnormalities in acute nonlymphoblastic leukemia. Cancer Genet Cytogenet 1984;11:332-50. 5. Grimwade D, Walker H, Oliver F, Wheatley K, Harrison C, Harrison G, et al. The importance of diagnostic cytogenetics on outcome in AML: analysis of 1,612 patients entered into the MRC AML 10 trial. Blood 1998;92:2322-33. 6. Slovak ML, Kopecky KJ, Cassileth PA, Harrington DH, Theil KS, Mohamed A, et al. Karyotypic analysis predicts outcome of preremission and postremission therapy in adult acute myeloid leukemia: a Southwest Oncology Group/Eastern Cooperative Oncology Group study. Blood 2000;96:4075-83. 7. Byrd JC, Mrózek K, Dodge RK, Carroll AJ, Edwards CG, Arthur DC, et al. Pretreatment cytogenetic abnormalities are predictive of induction success, cumulative incidence of relapse, and overall survival in adult patients with de novo acute myeloid leukemia: results from Cancer and Leukemia Group B (CALGB 8461). Blood 2002;100:4325-36. 8. Mrózek K, Heerema NA, Bloomfield CD. Cytogenetics in acute leukemia. Blood Rev 2004;18:115-36. 9. Schoch C, Kern W, Schnittger S, Hiddemann W, Haferlach T. Karyotype is an independent prognostic parameter in therapy-related acute myeloid leukemia (t-AML): an analysis of 93 patients with t-AML in comparison to 1,091 patients with de novo AML. Leukemia 2004;18:120-5. 10. Farag SS, Archer KJ, Mrózek K, Ruppert AS, Carroll AJ, 20. 21. 22. 23. 24. 25. 26. 27. 28. Vardiman JW, et al. Pretreatment cytogenetics add to other prognostic factors predicting complete remission and longterm outcome in patients 60 years of age or older with acute myeloid leukemia: results from Cancer and Leukemia Group B 8461. Blood 2006;108:63-73. Mrózek K, Prior TW, Edwards CG, Marcucci G, Carroll AJ, Snyder PJ, et al. Comparison of cytogenetic and molecular genetic detection of t(8;21) and inv(16) in a prospective series of adults with de novo acute myeloid leukemia: a Cancer and Leukemia Group B study. J Clin Oncol 2001;19:2482-92. Erickson P, Gao J, Chang K-S, Look T, Whisenant E, Raimondi S, et al. Identification of breakpoints in t(8;21) acute myelogenous leukemia and isolation of a fusion transcript, AML1/ETO, with similarity to Drosophila segmentation gene, runt. Blood 1992;80:1825-31. Liu P, Tarlé SA, Hajra A, Claxton DF, Marlton P, Freedman M, et al. Fusion between transcription factor CBFb/PEBP2b and a myosin heavy chain in acute myeloid leukemia. Science 1993;261:1041-4. Shurtleff SA, Meyers S, Hiebert SW, Raimondi SC, Head DR, Willman CL, et al. Heterogeneity in CBFb/MYH11 fusion messages encoded by the inv(16)(p13q22) and the t(16;16)(p13;q22) in acute myelogenous leukemia. Blood 1995;85:3695-703. de Bruijn MFTR, Speck NA. Core-binding factors in hematopoiesis and immune function. Oncogene 2004;23: 4238-48. Peterson LF, Zhang D-E. The 8;21 translocation in leukemogenesis. Oncogene 2004;23:4255-62. Shigesada K, van de Sluis B, Liu PP. Mechanism of leukemogenesis by the inv(16) chimeric gene CBFB/PEBP2BMHY11. Oncogene 2004;23:4297-307. Bloomfield CD, Lawrence D, Byrd JC, Carroll A, Pettenati MJ, Tantravahi R, et al. Frequency of prolonged remission duration after high-dose cytarabine intensification in acute myeloid leukemia varies by cytogenetic subtype. Cancer Res 1998;58:4173-9. Byrd JC, Dodge RK, Carroll A, Baer MR, Edwards C, Stamberg J, et al. Patients with t(8;21)(q22;q22) and acute myeloid leukemia have superior failure-free and overall survival when repetitive cycles of high-dose cytarabine are administered. J Clin Oncol 1999;17:3767-75. Byrd JC, Ruppert AS, Mrózek K, Carroll AJ, Edwards CG, Arthur DC, et al. Repetitive cycles of high-dose cytarabine benefit patients with acute myeloid leukemia and inv(16)(p13q22) or t(16;16)(p13;q22): results from CALGB 8461. J Clin Oncol 2004;22:1087-94. Schlenk RF, Benner A, Krauter J, Büchner T, Sauerland C, Ehninger G, et al. Individual patient data-based meta-analysis of patients aged 16 to 60 years with core binding factor acute myeloid leukemia: a survey of the German Acute Myeloid Leukemia Intergroup. J Clin Oncol 2004;22:374150. Marcucci G, Mrózek K, Ruppert AS, Maharry K, Kolitz JE, Moore JO, et al. Prognostic factors and outcome of core binding factor acute myeloid leukemia patients with t(8;21) differ from those of patients with inv(16): a Cancer and Leukemia Group B study. J Clin Oncol 2005;23:5705-17. Appelbaum FR, Kopecky KJ, Tallman MS, Slovak ML, Gundacker HM, Kim HT, et al. The clinical spectrum of adult acute myeloid leukaemia associated with core binding factor translocations. Br J Haematol 2006;135:165-73. Roskoski R Jr. Signaling by Kit protein-tyrosine kinase - the stem cell factor receptor. Biochem Biophys Res Commun 2005;337:1-13. Care RS, Valk PJM, Goodeve AC, Abu-Duhier FM, Geertsma-Kleinekoort WMC, Wilson GA, et al. Incidence and prognosis of c-KIT and FLT3 mutations in core binding factor (CBF) acute myeloid leukaemias. Br J Haematol 2003;121:775-7. Cairoli R, Beghini A, Grillo G, Nadali G, Elice F, Ripamonti CB, et al. Prognostic impact of c-KIT mutations in core binding factor leukemias. An Italian retrospective study. Blood 2006;107:3463-8. Paschka P, Marcucci G, Ruppert AS, Mrózek K, Chen H, Kittles RA, et al. Adverse prognostic significance of KIT mutations in adult acute myeloid leukemia with inv(16) and t(8;21): a Cancer and Leukemia Group B study. J Clin Oncol 2006;24:3904-11. Schnittger S, Kohl TM, Haferlach T, Kern W, Hiddemann W, Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 189 | 12th Congress of the European Hematology Association 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. Spiekermann K, et al. KIT-D816 mutations in AML1-ETOpositive AML are associated with impaired event-free and overall survival. Blood 2006;107:1791-9. Boissel N, Leroy H, Brethon B, Philippe N, de Botton S, Auvrignon A, et al. Incidence and prognostic impact of cKit, FLT3, and Ras gene mutations in core binding factor acute myeloid leukemia (CBF-AML). Leukemia 2006;20:965-70. Nanri T, Matsuno N, Kawakita T, Suzushima H, Kawano F, Mitsuya H, et al. Mutations in the receptor tyrosine kinase pathway are associated with clinical outcome in patients with acute myeloblastic leukemia harboring t(8;21)(q22;q22). Leukemia 2005;19:1361-6. Wang Y-Y, Zhou G-B, Yin T, Chen B, Shi J-Y, Liang W-X, et al. AML1-ETO and C-KIT mutation/overexpression in t(8;21) leukemia: implication in stepwise leukemogenesis and response to Gleevec. Proc Natl Acad Sci USA 2005;102:1104-9. Cammenga J, Horn S, Bergholz U, Sommer G, Besmer P, Fiedler W, et al. Extracellular KIT receptor mutants, commonly found in core binding factor AML, are constitutively active and respond to imatinib mesylate. Blood 2005;106:3958-61. Goemans BF, Zwaan CM, Miller M, Zimmermann M, Harlow A, Meshinchi S, et al. Mutations in KIT and RAS are frequent events in pediatric core-binding factor acute myeloid leukemia. Leukemia 2005;19:1536-42. Kohl TM, Schnittger S, Ellwart JW, Hiddemann W, Spiekermann K. KIT exon 8 mutations associated with corebinding factor (CBF)-acute myeloid leukemia (AML) cause hyperactivation of the receptor in response to stem cell factor. Blood 2005;105:3319-21. Growney JD, Clark JJ, Adelsperger J, Stone R, Fabbro D, Griffin JD, et al. Activation mutations of human c-KIT resistant to imatinib mesylate are sensitive to the tyrosine kinase inhibitor PKC412. Blood 2005;106:721-4. Beghini A, Bellini M, Magnani I, Colapietro P, Cairoli R, Morra E, et al. STI 571 inhibition effect on KITAsn822Lysmediated signal transduction cascade. Exp Hematol 2005; 33:682-8. Frost MJ, Ferrao PT, Hughes TP, Ashman LK. Juxtamembrane mutant V560GKit is more sensitive to Imatinib (STI571) compared with wild-type c-kit whereas the kinase domain mutant D816VKit is resistant. Mol Cancer Ther 2002;1:1115-24. Schittenhelm MM, Shiraga S, Schroeder A, Corbin AS, Griffith D, Lee FY, et al. Dasatinib (BMS-354825), a dual SRC/ABL kinase inhibitor, inhibits the kinase activity of wild-type, juxtamembrane, and activation loop mutant KIT isoforms associated with human malignancies. Cancer Res 2006; 66:473-81. Corbin AS, Griswold IJ, La Rosee P, Yee KW, Heinrich MC, Reimer CL, et al. Sensitivity of oncogenic KIT mutants to the kinase inhibitors MLN518 and PD180970. Blood 2004; 104:3754-7. Gleixner KV, Mayerhofer M, Aichberger KJ, Derdak S, Sonneck K, Böhm A, et al. PKC412 inhibits in vitro growth of neoplastic human mast cells expressing the D816Vmutated variant of KIT: comparison with AMN107, imatinib, and cladribine (2CdA) and evaluation of cooperative drug effects. Blood 2006;107:752-9. Farag SS, Ruppert AS, Mrózek K, Mayer RJ, Stone RM, Carroll AJ, et al. Outcome of induction and postremission therapy in younger adults with acute myeloid leukemia with normal karyotype: a Cancer and Leukemia Group B study. J Clin Oncol 2005;23:482-93. Mrózek K, Marcucci G, Paschka P, Whitman SP, Bloomfield CD. Clinical relevance of mutations and gene-expression changes in adult acute myeloid leukemia with normal cytogenetics: are we ready for a prognostically prioritized molecular classification? Blood 2007;109:431-48. Mrózek K, Döhner H, Bloomfield CD. Influence of new molecular prognostic markers in patients with karyotypically normal acute myeloid leukemia: recent advances. Curr Opin Hematol 2007;14:106-14. Baldus CD, Mrózek K, Marcucci G, Bloomfield CD. Clinical outcome of de novo acute myeloid leukaemia patients with normal cytogenetics is affected by molecular genetic alterations: A concise review. Br J Haematol. In press 2007. Bullinger L, Döhner K, Bair E, Fröhling S, Schlenk RF, Tibshirani R, et al. Use of gene-expression profiling to iden- 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. tify prognostic subclasses in adult acute myeloid leukemia. N Engl J Med 2004;350:1605-16. Valk PJM, Verhaak RGW, Beijen MA, Erpelinck CAJ, Barjesteh van Waalwijk van Doorn-Khosrovani S, Boer JM, et al. Prognostically useful gene-expression profiles in acute myeloid leukemia. N Engl J Med 2004;350:1617-28. Radmacher MD, Marcucci G, Ruppert AS, Mrózek K, Whitman SP, Vardiman JW, et al. Independent confirmation of a prognostic gene-expression signature in adult acute myeloid leukemia with a normal karyotype: A Cancer and Leukemia Group B study. Blood 2006;108:1677-83. Stirewalt DL Radich JP. The role of FLT3 in haematopoietic malignancies. Nat Rev Cancer 2003;3:650-65. Gilliland DG, Griffin JD. The roles of FLT3 in hematopoiesis and leukemia. Blood 2002;100:1532-42. Kottaridis PD, Gale RE, Frew ME, Harrison G, Langabeer SE, Belton AA, et al. The presence of a FLT3 internal tandem duplication in patients with acute myeloid leukemia (AML) adds important prognostic information to cytogenetic risk group and response to the first cycle of chemotherapy: analysis of 854 patients from the United Kingdom Medical Research Council AML 10 and 12 trials. Blood 2001;98:1752-9. Whitman SP, Archer KJ, Feng L, Baldus C, Becknell B, Carlson BD, et al. Absence of the wild-type allele predicts poor prognosis in adult de novo acute myeloid leukemia with normal cytogenetics and the internal tandem duplication of FLT3: a Cancer and Leukemia Group B study. Cancer Res 2001;61: 7233-9. Fröhling S, Schlenk RF, Breitruck J, Benner A, Kreitmeier S, Tobis K, et al. Prognostic significance of activating FLT3 mutations in younger adults (16 to 60 years) with acute myeloid leukemia and normal cytogenetics: a study of the AML Study Group Ulm. Blood 2002;100:4372-80. Kainz B, Heintel D, Marculescu R, Schwarzinger I, Sperr W, Le T, et al. Variable prognostic value of FLT3 internal tandem duplications in patients with de novo AML and a normal karyotype, t(15;17), t(8;21) or inv(16). Hematol J 2002;3:283-9. Schnittger S, Schoch C, Dugas M, Kern W, Staib P, Wuchter C, et al. Analysis of FLT3 length mutations in 1,003 patients with acute myeloid leukemia: correlation to cytogenetics, FAB subtype, and prognosis in the AMLCG study and usefulness as a marker for the detection of minimal residual disease. Blood 2002;100:59-66. Schnittger S, Schoch C, Kern W, Mecucci C, Tschulik C, Martelli MF, et al. Nucleophosmin gene mutations are predictors of favorable prognosis in acute myelogenous leukemia with a normal karyotype. Blood 2005;106:3733-9. Thiede C, Steudel C, Mohr B, Schaich M, Schäkel U, Platzbecker U, et al. Analysis of FLT3-activating mutations in 979 patients with acute myelogenous leukemia: association with FAB subtypes and identification of subgroups with poor prognosis. Blood 2002;99:4326-35. Beran M, Luthra R, Kantarjian H, Estey E. FLT3 mutation and response to intensive chemotherapy in young adult and elderly patients with normal karyotype. Leuk Res 2004;28:547-50. Stirewalt DL, Meshinchi S, Kussick SJ, Sheets KM, Pogosova-Agadjanyan E, Willman CL, et al. Novel FLT3 point mutations within exon 14 found in patients with acute myeloid leukaemia. Br J Haematol 2004;124:481-4. Reindl C, Bagrintseva K, Vempati S, Schnittger S, Ellwart JW, Wenig K, et al. Point mutations in the juxtamembrane domain of FLT3 define a new class of activating mutations in AML. Blood 2006;107:3700-7. Bienz M, Ludwig M, Oppliger Leibundgut E, Mueller BU, Ratschiller D, Solenthaler M, et al. Risk assessment in patients with acute myeloid leukemia and a normal karyotype [Erratum in: Clin Cancer Res 2005;11:5659]. Clin Cancer Res 2005;11:1416-24. Fröhling S, Schlenk RF, Stolze I, Bihlmayr J, Benner A, Kreitmeier S, et al. CEBPA mutations in younger adults with acute myeloid leukemia and normal cytogenetics: prognostic relevance and analysis of cooperating mutations. J Clin Oncol 2004;22:624-33. Baldus CD, Thiede C, Soucek S, Bloomfield CD, Thiel E, Ehninger G. BAALC expression and FLT3 internal tandem duplication mutations in acute myeloid leukemia patients with normal cytogenetics: prognostic implications. J Clin Oncol 2006;24:790-7. | 190 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 63. Whitman SP, Ruppert AS, Radmacher MD, Mrózek K, Paschka P, Kolitz JE, et al. FLT3 D835/I836 mutations predict worse disease-free survival (DFS) in younger adults with cytogenetically normal acute myeloid leukemia (CN AML) without FLT3 internal tandem duplications (ITD): A Cancer and Leukemia Group B (CALGB) study [abstract]. J Clin Oncol In press 2007. 64. Döhner K, Schlenk RF, Habdank M, Scholl C, Rücker FG, Corbacioglu A, et al. Mutant nucleophosmin (NPM1) predicts favorable prognosis in younger adults with acute myeloid leukemia and normal cytogenetics - interaction with other gene mutations. Blood 2005;106:3740-6. 65. Yoshimoto G, Nagafuji K, Miyamoto T, Kinukawa N, Takase K, Eto T, et al. FLT3 mutations in normal karyotype acute myeloid leukemia in first complete remission treated with autologous peripheral blood stem cell transplantation. Bone Marrow Transplant 2005;36:977-83. 66. Palmieri S, Ferrara F, Leoni F, Ciolli S, Pollio F, D'Amico MR, et al. Myeloablative chemotherapy followed by autologous stem cell infusion may overcome the adverse prognostic impact of FLT3 (foetal liver tyrosine kinase 3) mutations in patients with acute myeloid leukaemia and normal karyotype. Hematol Oncol 2007;25:1-5. 67. Bornhäuser M, Illmer T, Schaich M, Soucek S, Ehninger G, Thiede C. Improved outcome after stem-cell transplantation in FLT3/ITD-positive AML. Blood 2007;109:2264-5. 68. Gale RE, Hills R, Kottaridis PD, Srirangan S, Wheatley K, Burnett AK, et al. No evidence that FLT3 status should be considered as an indicator for transplantation in acute myeloid leukemia (AML): an analysis of 1,135 patients, excluding acute promyelocytic leukemia, from the UK MRC AML10 and 12 trials. Blood 2005;106:3658-65. 69. Fiedler W, Mesters R, Tinnefeld H, Loges S, Staib P, Dührsen U, et al. A phase 2 clinical study of SU5416 in patients with refractory acute myeloid leukemia. Blood 2003;102:2763-7. 70. Giles FJ, Stopeck AT, Silverman LR, Lancet JE, Cooper MA, Hannah AL, et al. SU5416, a small molecule tyrosine kinase receptor inhibitor, has biologic activity in patients with refractory acute myeloid leukemia or myelodysplastic syndromes. Blood 2003;102:795-801. 71. Smith BD, Levis M, Beran M, Giles F, Kantarjian H, Berg K, et al. Single-agent CEP-701, a novel FLT3 inhibitor, shows biologic and clinical activity in patients with relapsed or refractory acute myeloid leukemia. Blood 2004;103:366976. 72. Stone RM, DeAngelo DJ, Klimek V, Galinsky I, Estey E, Nimer SD, et al. Patients with acute myeloid leukemia and an activating mutation in FLT3 respond to a small-molecule FLT3 tyrosine kinase inhibitor, PKC412. Blood 2005;105:5460. 73. DeAngelo DJ, Stone RM, Heaney ML, Nimer SD, Paquette RL, Klisovic RB, et al. Phase 1 clinical results with tandutinib (MLN518), a novel FLT3 antagonist, in patients with acute myelogenous leukemia or high-risk myelodysplastic syndrome: safety, pharmacokinetics, and pharmacodynamics. Blood 2006;108:3674-81. 74. Piloto O, Nguyen B, Huso D, Kim K-T, Li Y, Witte L, et al. IMC-EB10, an anti-FLT3 monoclonal antibody, prolongs survival and reduces nonobese diabetic/severe combined immunodeficient engraftment of some acute lymphoblastic leukemia cell lines and primary leukemic samples. Cancer Res 2006;66:4843-51. 75. Yao Q, Nishiuchi R, Li Q, Kumar AR, Hudson WA, Kersey JH. FLT3 expressing leukemias are selectively sensitive to inhibitors of the molecular chaperone heat shock protein 90 through destabilization of signal transduction-associated kinases. Clin Cancer Res 2003;9:4483-93. 76. Yao Q, Nishiuchi R, Kitamura T, Kersey JH. Human leukemias with mutated FLT3 kinase are synergistically sensitive to FLT3 and Hsp90 inhibitors: the key role of the STAT5 signal transduction pathway. Leukemia 2005;19:1605-12. 77. George P, Bali P, Annavarapu S, Scuto A, Fiskus W, Guo F, et al. Combination of the histone deacetylase inhibitor LBH589 and the hsp90 inhibitor 17-AAG is highly active against human CML-BC cells and AML cells with activating mutation of FLT-3. Blood 2005;105:1768-76. 78. Hess JL. MLL: a histone methyltransferase disrupted in leukemia. Trends Mol Med 2004;10:500-7. 79. Schichman SA, Caligiuri MA, Strout MP, Carter SL, Gu Y, Canaani E, et al. ALL-1 tandem duplication in acute myeloid 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. leukemia with a normal karyotype involves homologous recombination between Alu elements. Cancer Res 1994;54:4277-80. Caligiuri MA, Strout MP, Lawrence D, Arthur DC, Baer MR, Yu F, et al. Rearrangement of ALL1 (MLL) in acute myeloid leukemia with normal cytogenetics. Cancer Res 1998;58:559. Schnittger S, Kinkelin U, Schoch C, Heinecke A, Haase D, Haferlach T, et al. Screening for MLL tandem duplication in 387 unselected patients with AML identify a prognostically unfavorable subset of AML. Leukemia 2000;14:796-804. Döhner K, Tobis K, Ulrich R, Fröhling S, Benner A, Schlenk RF, et al. Prognostic significance of partial tandem duplications of the MLL gene in adult patients 16 to 60 years old with acute myeloid leukemia and normal cytogenetics: a study of the Acute Myeloid Leukemia Study Group Ulm. J Clin Oncol 2002;20:3254-61. Bloomfield CD, Mrózek K, Caligiuri MA. Cancer and Leukemia Group B Leukemia Correlative Science Committee: major accomplishments and future directions. Clin Cancer Res 2006;12:3564s-71s. Whitman SP, Ruppert AS, Marcucci G, Mrózek K, Paschka P, Langer C, et al. Long-term disease-free survivors with cytogenetically normal acute myeloid leukemia and MLL partial tandem duplication: A Cancer and Leukemia Group B study. Blood. In press 2007. Whitman SP, Liu S, Vukosavljevic T, Rush LJ, Yu L, Liu C, et al. The MLL partial tandem duplication: evidence for recessive gain-of-function in acute myeloid leukemia identifies a novel patient subgroup for molecular-targeted therapy. Blood 2005;106:345-52. Pabst T, Mueller BU, Zhang P, Radomska HS, Narravula S, Schnittger S, et al. Dominant-negative mutations of CEBPA, encoding CCAAT/enhancer binding protein-a (C/EBPa), in acute myeloid leukemia. Nat Genet 2001;27:263-70. Boissel N, Renneville A, Biggio V, Philippe N, Thomas X, Cayuela J-M, et al. Prevalence, clinical profile and prognosis of NPM mutations in AML with normal karyotype. Blood 2005;106:3618-20. Grisendi S, Mecucci C, Falini B, Pandolfi PP. Nucleophosmin and cancer. Nat Rev Cancer 2006;6:493-505. Falini B, Mecucci C, Tiacci E, Alcalay M, Rosati R, Pasqualucci L, et al. Cytoplasmic nucleophosmin in acute myelogenous leukemia with a normal karyotype. N Engl J Med 2005; 352:254-66. Verhaak RGW, Goudswaard CS, van Putten W, Bijl MA, Sanders MA, Hugens W, et al. Mutations in nucleophosmin (NPM1) in acute myeloid leukemia (AML): association with other gene abnormalities and previously established gene expression signatures and their favorable prognostic significance. Blood 2005;106:3747-54. Bardet V, Costa LD, Elie C, Malinge S, Demur C, Tamburini J, et al. Nucleophosmin status may influence the therapeutic decision in de novo acute myeloid leukemia with normal karyotype. Leukemia 2006;20:1644-6. Thiede C, Koch S, Creutzig E, Steudel C, Illmer T, Schaich M, et al. Prevalence and prognostic impact of NPM1 mutations in 1,485 adult patients with acute myeloid leukemia (AML). Blood 2006;107:4011-20. Niksic M, Slight J, Sanford JR, Caceres JF, Hastie ND. The Wilms' tumour protein (WT1) shuttles between nucleus and cytoplasm and is present in functional polysomes. Hum Mol Genet 2004;13:463-71. Summers K, Stevens J, Kakkas I, Smith M, Smith LL, Macdougall F, et al. Wilms' tumour 1 mutations are associated with FLT3-ITD and failure of standard induction chemotherapy in patients with normal karyotype AML. Leukemia 2007;21:550-1. King-Underwood L, Pritchard-Jones K. Wilms' tumor (WT1) gene mutations occur mainly in acute myeloid leukemia and may confer drug resistance. Blood 1998;91:2961-8. Tanner SM, Austin JL, Leone G, Rush LJ, Plass C, Heinonen K, et al. BAALC, the human member of a novel mammalian neuroectoderm gene lineage, is implicated in hematopoiesis and acute leukemia. Proc Natl Acad Sci USA 2001;98:139016. Baldus CD, Tanner SM, Ruppert AS, Whitman SP, Archer, KJ, Marcucci G, et al. BAALC expression predicts clinical outcome of de novo acute myeloid leukemia patients with normal cytogenetics: a Cancer and Leukemia Group B study. Blood 2003;102:1613-8. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 191 | 12th Congress of the European Hematology Association 98. Oikawa T, Yamada T. Molecular biology of the Ets family of transcription factors. Gene 2003;303:11-34. 99. Oikawa T. ETS transcription factors: possible targets for cancer therapy. Cancer Sci 2004;95:626-33. 100. Marcucci G, Baldus CD, Ruppert AS, Radmacher MD, Mrózek K, Whitman SP, et al. Overexpression of the ETSrelated gene, ERG, predicts a worse outcome in acute myeloid leukemia with normal karyotype: a Cancer and Leukemia Group B study. J Clin Oncol 2005;23:9234-42. 101. Marcucci G, Maharry K, Whitman SP, Paschka P, Langer C, Mrózek K, et al. High ERG expression predicts adverse outcome and refines molecular risk-based classification of cytogenetically normal (CN) acute myeloid leukemia (AML): A Cancer and Leukemia Group B (CALGB) study [abstract]. Proc Am Assoc Cancer Res. In press 2007. 102. Meester-Smoor MA, Molijn AC, Zhao Y, Groen NA, Groffen CAH, Boogaard M, et al. The MN1 oncoprotein activates transcription of the IGFBP5 promoter through a CACCC-rich consensus sequence. J Mol Endocrinol 2007;38:113-25. 103. Lekanne Deprez RH, Riegman PHJ, Groen NA, Warringa UL, van Biezen NA, Molijn AC, et al. Cloning and characterization of MN1, a gene from chromosome 22q11, which is disrupted by a balanced translocation in a meningioma. Oncogene 1995;10:1521-8. 104. Buijs A, Sherr S, van Baal S, van Bezouw S, van der Plas D, Geurts van Kessel A, et al. Translocation (12;22)(p13;q11) in myeloproliferative disorders results in fusion of the ETS-like TEL gene on 12p13 to the MN1 gene on 22q11. Oncogene 1995;10:1511-9. 105. Heuser M, Beutel G, Krauter J, Döhner K, von Neuhoff N, Schlegelberger B, et al. High meningioma 1 (MN1) expression as a predictor for poor outcome in acute myeloid leukemia with normal cytogenetics. Blood 2006;108:3898905. 106. Gilliland DG. Hematologic malignancies. Curr Opin Haematol 2001;8:189-91. 107. Reilly JT. Pathogenesis of acute myeloid leukaemia and inv(16)(p13;q22): a paradigm for understanding leukaemogenesis? Br J Haematol 2005;128:18-34. 108. Golub TR, Slonim DK, Tamayo P, Huard C, Gaasenbeek M, Mesirov JP, et al. Molecular classification of cancer: class discovery and class prediction by gene expression monitoring. Science 1999;286:531-7. 109. Haferlach T, Kohlmann A, Schnittger S, Dugas M, Hiddemann W, Kern W, et al. Global approach to the diagnosis of leukemia using gene expression profiling. Blood 2005;106: 1189-98. 110. Ichikawa H, Tanabe K, Mizushima H, Hayashi Y, Mizutani S, Ishii E, et al. Common gene expression signatures in t(8;21)- and inv(16)-acute myeloid leukaemia. Br J Haematol 2006; 135:336-47. 111. Alcalay M, Tiacci E, Bergomas R, Bigerna B, Venturini E, Minardi SP, et al. Acute myeloid leukemia bearing cytoplasmic nucleophosmin (NPMc+ AML) shows a distinct gene expression profile characterized by up-regulation of genes involved in stem-cell maintenance. Blood 2005;106:899-902. 112. Wilson CS, Davidson GS, Martin SB, Andries E, Potter J, Harvey R, et al. Gene expression profiling of adult acute myeloid leukemia identifies novel biologic clusters for risk classification and outcome prediction. Blood 2006;108:68596. 113. Bullinger L, Valk PJM. Gene expression profiling in acute myeloid leukemia. J Clin Oncol 2005;23:6296-305. 114. Marshall E. Getting the noise out of gene arrays. Science 2004;306:630-1. | 192 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Acute Myeloid Leukemia Management of elderly patients with acute myeloid leukemia H. Dombret E. Raffoux L. Degos From the Department of Clinical Hematology Saint-Louis Hospital, University Paris, Paris, France Hematology Education: the education program for the annual congress of the European Hematology Association 2007;1:193-199 dvances in the treatment of younger patients with acute myeloid leukemia (AML) have been obtained with intensified treatments such as high-dose chemotherapy or allogeneic stem cell transplantation. However, AML is predominantly a disease of the elderly and these options are not appropriate for patients over 50 to 60 years old. In older patients, even the advantages offered by standard intensive chemoteraphy are still open to discussion because of excessive toxicity and short duration of response. Factors related to age, including poor performance status (PS), pharmacodynamic changes, and organ dysfunctions, may negatively impact on treatment tolerance.1-5 Factors related to disease biology, including more frequent prior myelodysplastic syndrome (MDS), expression of a multidrug resistance (MDR) phenotype, and unfavorable karyotype, may lower the response rate and response duration.1-5 In a recent retrospective American survey, the outcome of elderly patients with AML was very poor with a median survival of 2 months and a 2-year survival rate of 6%. Only a minority of patients underwent chemotherapy within two years after AML diagnosis.6 The proportion of elderly patients treated intensively is probably slightly higher in European countries than in the United States, but does not exceed 30 to 40% even when considering only de novo AML patients. The eligibility of older patients with AML for standard chemotherapy must be appropriately defined. This is particularly important because many of the new agents and therapeutic strategies being developed in AML are only proposed for these so-called unfit patients. However, some of these new agents may also benefit fit patients when combined with standard chemotherapeutic agents. This has led to a great deal of current research in these patients. A Standard intensive chemotherapy Objectives and results of the recent prospective randomized trials using intensive chemotherapy in older patients with AML are summarized in Table 1. As indicated, study objectives were essentially hematopoietic growth factors (HGF) (9 studies),8-11,14-16,18,19,22 anthracyclines or induction regimen (5 studies),7,12,13,17,18,25 postremission therapy (5 studies),7,12-15,20,21,25 alltrans retinoic acid (1 study),20,21 MDR modulation (1 study),23 and interleukin-2 (IL-2) maintenance (1 study).24 Response to intensive induction Induction death (ID) Compared to earlier reports,26 CR rates have only slightly improved during the last 15-year period and are now 50-60% (Table 1). This is much lower than in younger patients. A reduction in ID rate (now usually 10-20%) has been progressively observed. This reduction may be related to a more rigorous selection of patients, but other positive factors may have played a role. The state of health of people aged around 70 years of age has improved and these patients present less frequent or severe pretreatment comorbidities. Advances in supportive care, notably antifungal therapies, may have also contributed. Surprisingly, all studies which tested the ability of granulocyte or granulocyte-macrophage colony-stimulating factor (G-CSF and GM-CSF) to reduce ID rate gave negative results, even if both factors were able to significantly reduce the duration of chemotherapy-induced neutropenia without affecting response and response duration. This means that the role of G-CSF and GM-CSF in elderly AML management is not clearly defined, although HGF administration may reduce hospitalization duration, a particular problem for these older patients. Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 193 | 12th Congress of the European Hematology Association Resistant disease Resistant disease after intensive induction (25 to 45%) is now the main cause of failure in older patients. Compared to younger patients, higher resistance disease (RD) rates are also observed when considering only patients with AML-nk, suggesting that the trend towards more unfavorable cytogenetics is not the only determining factor for the higher resistance rates observed in older patients. We have already mentioned the more frequent expression of a MDR phenotype, which has been shown to influence the outcome independently of unfavorable cytogenetics.27 Poor-prognosis internal tandem duplications of the FLT3 gene do not appear to be more frequent in older patients.28-30 The incidence of good-prognosis NPM1 mutations has not yet been fully defined in older patients and might play a role. In a gene expression profile study, unsupervised clustering of samples from 170 older patients with AML (median age, 65 years) identified a cluster of 24 patients associated with NMP1 mutation and a relatively favorable outcome.31 Interestingly, the highest rate of RD was observed in a cluster of 22 patients with notable MDR gene expression. Finally, genome-wide analysis using comparative genomic hybridization (CGH) or single nucleotide polymorphism (SNP) arrays which are currently being performed in large cohorts of pediatric, younger, and older AML patients will probably identify those with cryptic abnormalities associated with resistance to standard chemotherapy. At present, most attempts to Table 1. Response to intensive induction chemotherapy (period 1990-2006). Study (period) Study objectives Patients (N) Median age (years) Secondary AML (%) Normal or favorable cytogenetics* (%) CR rate (%) ID rate (%) RD rate (%) EORTC-HOVON7 (1986-1993) Anthracycline Post-remission 489 68 10 38 42 18 40 AMLCSG8 (1990-1992) HGF 173 71 0 49 59 17 24 ECOG9 (1990-1992) HGF 117 64 0 NA 52 NA NA EORTC-HOVON10 (1990-1994) HGF 318 68 22 48 56 13 31 GOELAMS11 (1992-1994) HGF 240 66 0 58 62 16 22 MRC 12,13 (1990-1998) Induction regimen Post-remission 1311 66 23 55 55 19 26 CALGB14,15 (1990-1993) HGF Post-remission 388 69 0 NA 53 25 22 SWOG16 (1992-1994) HGF 211 68 24 NA 46 19 35 SWOG17 (1995-1998) Induction regimen 328 67 23 36 38 17 45 ECOG18 (1993-1997) Anthracycline HGF 348 68 NA 50 42 17 41 HGF 110 77 0 NA 65 12 23 ATRA Post-remission 242 66 16 NA 33 13 54 HGF 722 68 22 50 55 14 31 HOVON-MRC23 (1997-1999) MDR modulation 419 67 25 56 51 15 34 CALGB24 (1998-2002) IL-2 maintenance 669 71 27 NA 46 NA NA ALFA25 (1999-2006) Anthracycline Post-remission 416 72 15 53 57 10 33 Swedish group19 (1992-1999) AMLSG20,21 (1997-2003) EORTC-GIMEMA22 (1995-2001) * Percentage is given in patients with adequate cytogenetic study; HGF: hematopoietic growth factor; MDR: multidrug resistance; CR: complete remission; ID: induction death; RD: resistant disease; NA: not available. | 194 | Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) Vienna, Austria, June 7-10, 2007 Table 2. Cytogenetic risk subsets. Younger AML studies* Older AML studies MRC (N= 1065 patients) CALGB (N= 635 patients) AMLSG4 (N= 361 patients) HOVON41 (N=293 patients) t(8;21) inv(16)/t(16;16) t(8;21) inv(16)/t(16;16) t(8;21) inv(16)/t(16;16) inv(16)/t(16;16) t(8;21) inv(16)/t(16;16) Other Other Other Normal t(8;21) 11q abns +8, +11 Normal -Y 7q- Complex –7, 3q abns. ± -5, 5q-, 7q+8, t(6;9), t(9;22) 9q, 11q, 20q, 21q, 17p abns. Complex Complex Rare aberrations Other Other 13 Favorable (Low-risk) Intermediate (Standard-risk) Unfavorable (High-risk) 5 * According to MRC, SWOG/ECOG, and CALGB classifications for younger adults42; abns: abnormalities. significantly reduce the rate of RD after intensive induction have failed. Studies evaluating variations of or additions to the standard 3+7 regimen (daunorubicin, 45-60 mg/m2 for 3 days; cytarabine, 100-200 mg/m2 CI for 7 days) were essentially negative. MDR modulation using either PSC-833 or zosuquidar did not increase the response rate.23,32,33 Some results were observed in studies testing HGF with the aim of priming AML blasts in the cell cycle during chemotherapy.10,11,18,19,22 But although HGF priming has been reported to be beneficial in younger patients with standardrisk AML,34,35 results were more heterogeneous in older patients.36 No recommendation on G-CSF or GM-CSF priming may therefore be made in elderly AML patients. A very interesting recent study which awaits confirmation showed increased CR rate, longer eventfree and overall survival when all-trans retinoic acid (ATRA) was added to standard ICE chemotherapy.20 Finally, the addition of fludarabine to cytarabine and G-CSF failed to show any significant improvement.37 Selection of eligible patients There are no standardized selection criteria for intensive chemotherapy. As a consequence, selection bias may vary from one study to another, making valuable comparisons difficult. In patients enrolled in prospective trials, trial eligibility criteria are an important first selection step usually including favorable PS, the absence of organ failure, severe uncontrolled infection, psychiatric disease, or central nervous system involvement. However, most investigators would agree that patients are also more subjectively selected according to their physiological age and associated comorbidities. Their own willingness to receive or not receive intensive chemotherapy is also an important factor. Usually, intensive treatment is not offered to patients aged 80 years or more. Very recently, a refined comorbidity index, namely the Hematopoetic Cell Transplantation Comorbidity Index (HCTCI), has also been used in elderly patients with AML.38-40 Even if HCTCI was identified as an independent prognostic factor for outcome, a larger evaluation of the sensitivity and specificity of each HCTCI item by itself is needed to more precisely define AML patients unlikely to benefit from intensive therapy because of unacceptable toxicity. Some AML features such as cytogenetics and prior MDS also influence this decision. This can be seen from the variations observed in the proportion of patients with secondary AML or AML with a normal or favorable karyotype enrolled in the trials listed in Table 1. In four recent studies evaluating the prognostic value of cytogenetics exclusively in older patients, some important differences or uncertainties may be noted (Table 2).4,5,13,41 It seems, however, that the optimal classification for older patients should clearly differ from the classification(s) used in younger patients (Table 2).42 First, core binding factor (CBF) leukemias which represent the favorable subset in younger patients are much less frequent in older patients and appear to be also less favorable.3,13,41 It is even unclear whether all these CBF-AMLs are to be associated with a better prognosis than AMLs with a normal karyotype (AML-nk) in older patients.3,4,13 At the other end of the spectrum, due to relatively low numbers of patients and the relatively poor outcome in general, the unfavorable subset is difficult to define. Only very unfavorable features such as complex karyotype always identify patients with a significantly worse outcome (Table 2). Hematology Education: the education program for the annual congress of the European Hematology Association | 2007; 1(1) | 195 | 12th Congress of the European Hematology Association Incorporation of more recently developed agents Emerging agents for older AML treatment were reviewed last year by S. Amadori and R. Stasi in the EHA 2006 Education Program.43 Because of their predominant hematologic toxicity, some of these agents are candidates for combination with standard chemotherapeutic agents in the context of an intensive treatment. Some others may be combined with intensive chemotherapy to sensitize AML blasts to chemotherapy-induced damage. Gemtuzumab ozogamicin (GO) is approved in the US for the treatment of patients with CD33-positive AML in first relapse aged 60 years or older who are not considered to be candidates for standard chemotherapy. In a sequential front-line Phase II study, GO has been used as single agent before standard intensive chemotherapy.44 Several cooperative groups are currently investigating the role of GO administered concomitantly to first line chemotherapy, mainly in younger adults. The first very interesting results came last year from the British MRC Phase III AML-15 study.45 The addition of intermediate-dose GO (3 mg/m2 for one dose) to the first and third courses of chemotherapy significantly reduced the risk of relapse and prolonged diseasefree survival (DFS) without a significant advantage in terms of overall survival (OS), at least with the present follow-up. Some patients aged 60 years or more were included in this study and seemed to tolerate the combined treatment well. However, larger specific studies are needed for these patients. GO is less effective in AML blasts expressing a MRD phenotype. This might make it less beneficial in older patients. Clofarabine is a next generation purine nucleoside analog approved for the treatment of children with refractory or relapsing acute lymphoblastic leukemia. In adults, interesting results have been recently reported in patients with AML. In patients eligible for intensive therapy, clofarabine has been combined with intermediate-dose cytarabine,46 anthracycline with or without cytarabine,47 or anthracycline and GO.48 Larger front-line studies are needed to confirm the promising potential of these combined therapies, especially in older patients. Cloretazine is a novel sulfonylhydrazine alkylating agent which has recently been reported to be associated with significant efficacy and modest extrahematologic toxicity when administered as a single agent to older patients with previously untreated AML.49 Intensive induction combining cloretazine with usual chemotherapeutic agents may be another option that could be tested. Liposomal daunorubicin might also be of interest in older AML patients, as recently reported in a phase III study from the Italian GIMEMA group.50 Bortezomib, FLT3 inhibitors, or bcl2 antisens,51 may also be good candidates to combine with standard chemotherapeutic agents, to sensitize AML blasts to chemotherapy-induced apoptosis. Post-remission therapy and relapses Consolidation chemotherapy There is no confirmed post-remission strategy in elderly patients with AML once CR has been reached using standard intensive induction. Highdose consolidation courses, with or without highdose cytarabine, are usually too toxic to benefit most of these patients, as a large number of them may not receive all programed treatment because of acquired comorbidities. On the other hand, beneficial effects associated with prolonged therapy with lower doses of chemotherapy have been reported in elderly patients but not in younger patients.7,52 In the ALFA-9803 study, CR patients randomized to receive a consolidation therapy with six relatively mild cycles as out-patients had a longer DFS and OS than those randomized to receive one intensive induction-like cycle.25 The neeed for re-hospitalization, transfusions, and intravenous antibiotics was significantly less in those treated as out-patients. Interesting large, cooperative group studies testing prolonged maintenance with new agents such as GO, tipifarnib, or 5-azacitidine have been carried out or are ongoing. However, results are not yet available. Allogeneic stem cell transplants Allogeneic stem cell transplantation
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