Data Interpretation of Hb and protein Electrophoresis 台北醫學大學細分所所長李宏模教授 Data Interpretation of Hb and protein Electrophoresis z Hemoglobin z z Normal Hb Pathological Hb z z z Sickle cell Anemia α-thalassemia β-thalassemia z Protein z z electrophoresis electrophoresis Normal Pathological z z multiple myeloma other pathological profiles 1 Anemia z Depletion anemia z Production defect anemia z z Aplastic anemia/ marrow replacement factor deficiency z z z z Vitamin B12 Folic acid iron deficiency hemoglobinopathies 2 Normal Hb in fetal stage z Embryonic z z z z Gower 1 = ζ2ε2 Portland 1 = ζ2γ2 Gower 2 = α2ε2 At birth A = α2β2 (25%) z Hb F = α2γ2 (75%) z Hb 3 Normal Hb in adult Hb A = α2β2 (97%) z Hb F = α2γ2 (<1 %) z Hb A2 = α2δ2 (2.5%) z 4 Pathological conditions z Hemoglobinopathies Structural Hb variants Substitution, addition, or deletion of one or more amino acids of the globin (b) Thalasssemias Quantitative defect in globin chain production (c) Combination of (a) and (b) (d) Hereditary persistence of fetal Hb (a) Nomenclature of Hb variants HbA, HbF, and HbS were first discovered z Additional variants start from HbC z Too many variants were found(>500) z z z z Hb with similar electrophoretic motility distinguished by adding the place of discover Some new Hb were named by pts’ family z New z z system HbS B6 GluÆ Val (E B6 V) HbC B6 GluÆ Lys (E B6 K) 5 Classification of Hb variants z Amino z acid substitution e.g. Sickle cell anemia z Deletion z and insertion e.g. thalassemia (α chain deletion) z Unequal cross over (fusion genes) z Chain elongation z Frame shift variants 6 Clinical consequences of abnormal Hb z Asymptomatic if they don’t interfere with Hb functions Æ unstable Hb z Produce disease z affect the stability, shape, or function of Hb z Homozygous z for abnormal Hb HbS z Heterozygous z are mostly mild HbC, HbD, HbE but not HbA-HbS Unstable Hb z Hemolytic anemia z Hemichrome formation (Heme iron form various side chain with globin) globin) z Inclusion body formation (Heinz bodies) z Altered oxygen dissociation z Altered hemoglobin stability Æ Increase methemoglobin (Fe++ Æ Fe+++) and sufhemoglobin z Altered solubility (Target cells) 7 Sickle cell anemia zB chain 6th amino acid EÆ V substitution results in polymerization of deoxy form within the red cells z The sickled-shape cells block microcirculation z Stasis Æ hypoxia and ischemic infarction of liver, kidney, heart, bone, nervous system z Hemolytic anemia or even DIC 8 Varying clinical severity of the different sickle syndrome z Sickle z z z SA (30-40% HbS) (mild severity) SF (70% HbS) (mild severity) SC (50% HbS) (+++ severity) z Sickle z z z cell trait cell anemia hemolytic anemia aplastic crisis vaso-occlusive z Sickle cell-HbC disease 9 Thalassemia z Decreased z rate of globin chain production thalassemia γ, ε, ζ Æ embryonic death z Classification z z z Thalassemia major thalassemia minor thalassemia minima z Alpha-thalassemia z Beta-thallasemia z β+ or β0-thalassemia 10 11 Hemoglobin protein has two alpha subunits and two beta subunits. z The two chromosomes #11 have one beta globin gene each (for a total of two genes). z The two chromsomes #16 have two alpha globin genes each (for a total of four genes). z Each alpha globin gene produces only about half the quantity of protein of a single beta globin gene. 12 Alpha-thalassemia z Defective z No α-chain synthesis elevation of HbA2 and HbF (↑in β-thalassemia) z Consequence z z z z of diminished α-chain synthesis decrease production of HbA, HbF, HbA2 Excess β-chain and γ-chain Hb Bart’s (γ4) HbH (β4) 13 The offspring that inherits the double deletion from one parent and the single from the other will have Hemoglobin H disease (Scenario 1). The offspring who inherits no alpha genes from the parents dies in utero (Scenario 2; hydrops fetalis). Beta-thalassemia z Defective β-chain synthesis (β+ or β++)or absent (β0 ) of β-globin z elevation of HbA2 & HbF in β-thalassemia z Diminished z Consequence of diminished β-chain synthesis decrease production of HbA, z Excess γ-chain and δ-chain z HbF z HbA2 z No Hb Bart’s (γ4) z No HbH (β4) z 14 15 Hb electrophoresis (alkaline) z Separation on cellulose acetate (pH8.4) (-) A2 Æ S Æ F Æ A1 (+) z Most frequently used z Resolve most of the major Hbs (A1, A2, S, F) z A2 can not be separated from C z Can not resolve HbD, G; and HbC, E 16 Hb electrophoresis (acidic) z Separation on agarose gel (pH6.0) (-) F A S C (+) z Mostly used in confirmation z E can be separated from C z HbC, HbS migrate toward the Anode z HbA, E migrate toward the cathode 17 Protein electrophoresis z Multiple myeloma and Immunoglobulins z Data of protein electrophoresis z z z z z z z z Acute reaction pattern Nephrotic syndrome Chronic inflammation Cirrhosis of liver a1-antitrypsin deficiency (chronic diseases) polyclonal gammopathies hypogammaglobulinemia Multiple myeloma (M spike) 18 Issues to be discussed z Structure and function of Immunogloblins z Clonal deletion and clonal expansion z Development of lymphocytic lineage z Multiple myeloma z Consequences of multiple myeloma z Normal patterns of protein electrophoresis z Pathological patterns 19 20 Multiple myeloma z Maturation of plasma cells z Proliferation of plasmacytoid lymphocytes z Proliferation of plasma cells z Principle of data interpretation z Blood z z z z Hyperviscosity Cryoglobulinemia M spike Bence Jones proteinuria 21 22 Bone marrow aspirate demonstrating plasma cells of multiple myeloma. Note the blue cytoplasm, eccentric nucleus, and perinuclear pale zone (or halo). multiple punched-out lesions in a patient with multiple myeloma 23 24 Bence Jones proteins z z z z The multiple myeloma cell clone produces an excess of monoclonal (M proteins) and free light chain proteins. The M proteins may be recognized as IgA, IgD, IgG, IgE or IgM, depending on their heavy chain class. The light chain proteins may be designated as kappa or lambda. They may precipitate and deposit, producing organ damage. The organ most commonly affected is the kidney. When these monoclonal light chains appear in the urine, they are called Bence Jones proteins. 25 Routine laboratory z z z Pancytopenia, abnormal coagulation, hypercalcemia, azotemia, elevated alkaline phosphatase and erythrocyte sedimentation rate, and hypoalbuminemia. Proteinuria, hypercalciuria, or both. Urine dipstick tests may not indicate the presence of Bence Jones proteinuria. All patients with suspected multiple myeloma require a 24-hour urinalysis by protein electrophoresis to determine the presence of Bence Jones proteinuria and kappa or lambda light chains. 26 Protein electrophoresis z Supporting matrix z Molecular charge z z Molecular charge and size z z Starch and polyacrylamide pH and ionic strength of buffer z z z Agarose, Agarose, cellulose acetate pH 8.6 Æ most proteins are negative charge barbital, TrisTris-barbital, boric acid, Tris and EDTA Visualization z z Coomasie brilliant blue, Ponsceus S (albumin>globulin) Amido black (agarose (agarose gel), bromphenol blue, 27 Data interpretation of protein electrophoresis z Protein electrophoresis z Data interpretation of z Normal z Acute reaction pattern (2, 3) z Nephrotic syndrome (4) z Chronic inflammation (5) z Cirrhosis of liver (6, 7, 8) z a1-antitrypsin deficiency (chronic diseases) (9) z polyclonal gammopathies (10) z hypogammaglobulinemia (11) z Multiple myeloma (M spike) (12) 28 姓名學號 1. Normal 2 3 4 5 6 7 8 9 10 11 12 29