Department of Pharmacology and Therapeutics 4th Medical lectures 20/Oct/2005 Suspicion of DPLD • Dyspnoea/Cough • Symptoms often subtle, non specific and slowly progressive • Long period before diagnosis confirmed • Some patients are asymptomatic – Diagnosed on the basis of abnormal radiology /PFTs • Need to maintain an index of suspicion – Esp if environmental/occupational exposures/ concomitant medical conditions aetiology • Incidence – Males 31.5/100,000 – Females 26.1/100,000 • Pathogenesis – Injury to the lung coupled with attempts to heal Classification • ATS/ERS consensus statement – DPLD secondary to identificable causes • • • • Environmental Occupational Drugs CTD/IBD – DPLD secondary to granulomatous diseases – Rare DPLD with well defined clinicopathological features • • • • – IIP LAM Histiocytosis X Eosinophilic pneumonia Pulmonary alveolar proteinosis Inhaled Agents Connective Tissue Disease Inorganic: Scleroderma Polymyositis/dermatomyositis Systemic lupus erythematosus Rheumatoid arthritis Mixed connective tissue disease Ankylosing spondylitis Primary Sjögren's syndrome Behçet's syndrome Silica Asbestos Beryllium Organic: Animal/bird antigens Farm antigens Drug-Induced Antibiotics Antiarrhythmics Anti-inflammatory agents Chemotherapeutic agents Antidepressants Radiation Oxygen Infectious Atypical pneumonias Pneumocystis carinii pneumonia Tuberculosis Idiopathic Sarcoidosis Eosinophilic granuloma Idiopathic Interstitial Pneumonia (IIP) Bronchiolitis obliterans organizing pneumonia (OP) Lymphocytic interstitial pneumonia (LIP) Usual interstitial pneumonia (UIP) Nonspecific interstitial pneumonia (NSIP) Desquamative interstitial pneumonia (DIP) Respiratory bronchiolitis with interstitial lung disease (RB-ILD) Acute interstitial pneumonia (AIP). Malignant Lymphangitic carcinomatosis Bronchoalveolar cell carcinoma Miscellaneous Lymphangioleiomyomatosis Histiocytosis X Adapted from Flaherty and Martinez. Diagnostic approach • ATS/ERS – Integrated clinical, radiological and pathological approach – Essential to diagnosis UIP/IPF • • • • • History Examinaton Selected lab studies Imaging studies In selected patients – TBBX/Surgical Biopsy Clinical History • Sex – LAM, Tuberosis Sclerosis – premenopausal women – Women with IPF have a better prognosis • Age – sarcoidosis, Familial IPF, Eosinophilic Granuloma • • • • • Co morbidity – CTD, IBD Drug exposure - BPMAN Assessment of living and work conditions Occupation/ social/leisure Risks for HIV Symptoms • • • Dyspnoea Cough Other symptoms – Haemoptysis • alveolar hemorrhage syndromes, pulmonary vascular diseases, lymphangioleiomyomatosis, tuberous sclerosis, and chronic mitral valve disease. – Pleuritic chest pain • collagen vascular illness, or a pneumothorax in patients with lymphangioleiomyomatosis, tuberous sclerosis, or eosinophilic granuloma. – Onset of symptoms can give clues • Acute process: – atypical infections, eosinophilic pneumonia, pulmonary hemorrhage, Wegener's granulomatosis, AIP, initial hypersensitivity reactions, or bronchiolitis obliterans organizing pneumonia (BOOP). • Sub-Acute/Chronic process: – IPF, silica- or asbestos-related lung disease, long-standing hypersensitivity pneumonitis (HP), drug-induced lung diseases Occupational/ Environmental history • Diagnostic importance • Therapeutic importance • Occupational exposure – Often long latent period • avian, animal, fish proteins, fungal spores, asbestos, silica, cobalt, beryllium, aluminum, isocyanates, and copper sulfate. • Home • The presence or absence of pets, especially birds Medications: • http://www.pneumotox.com Smoking history • RBILD, DIP, and eosinophilic granuloma – Almost exclusively in smokers • HP/EAA – Less common in smokers – If occurs in smokers – more severe and chronic Examination • The physical examination are generally nonspecific. • Dry bibasilar crackles, although inspiratory high-pitched rhonchi (“squeaks”) can be seen with bronchiolar disorders. • Clubbing (most common in IPF) • Right heart failure • Signs of underlying connective tissue disorders. Physiology • Restrictive pattern • Laboratory features – FBC – Electrolytes – Autoantibody screen – Inflammatory markers Radiology • Chest X-Ray (20% Normal) • HRCT HRCT Findings in IPF • Bibasal subpleural distribution • Reticular shadowing • Honeycombing • Lack of ground glass opacification • Widened interlobular septae • Tractional bronchiectasis HRCT NSIP/ Path NSIP HRCT NSIP/ Path UIP HRCT UIP/ Path UIP BAL/TBBX/Lung biopsy • Depends on clinical suspicion • Risk v benefit • Presence of classical clinical and radiological features Concordant UIP Discordant UIP NSIP IPF Survival Daniil ZD et al. Am J Respir Crit Care Med. 1999; 160:899 Bjoraker JA et al. Am J Respir Crit Care Med. 1998; 157: 199 • No data exist that adequately documents that any of the current treatment approaches – Improve survival or – Quality of life for patients • “Until adequate studies are conducted that define the best treatment for patients with IPF, this committee suggests… combined therapy (corticosteroid and either azathioprine or cyclophosphamide) for patients…who possess features consistent with a more likely favourable outcome” Interferon Gamma (INF-γ 1b) • • • • • • Rationale for use Pilot study, 1999 Raghu 2004: R, MC, PC, DB; 330 patients 48 week follow up SC TIW Failed to reach primary efficacy endpoint Interferon Gamma Raghu G, et al N Eng J Med, 2004; 350: 125-33 Interferon Gamma INSPIRE International Study of Survival Outcomes in Idiopathic Pulmonary Fibrosis with Interferon Gamma 1-b 2 years, 600 pts, 75 centres, Less severe disease FVC >55% DLCO >35% • • • • • • Pirfenidone: Rationale for Therapy Antifibrotic agent Decreases fibroblast proliferation Decreases ECM production Inhibits TGF-β collagen synthesis Inhibits mitogenic effect of PDGF Ameliorated fibrosis in a hamster model of bleomycin lung • Beneficial effect in Hermansky-Pudlak syndrome • Orally active • Safe Pirfenidone • • • • • Initial trial Raghu et al, 1999 Osaka et al, 2004: R, PC, DB, MC trial 107 pts Dose titrated to 600 t.i.d. 1º endpoint lowest O2 saturation at 6MWT 2º endpoints: – – – – Change in baseline pulmonary function Events of acute exacerbation of IPF QOL score Disease progression by HRCT pattern Pirfenidone • Study aborted by DSMB – Interim analysis of endpoints • Acute exacerbations of IPF: 5 vs. 0 • p =0.0032 • ADR: photosensitivity & nausea • INTERMUNE sponsored larger RCT N-Acetyl Cysteine • Rationale for use – Oxidative stress – Glutathione • NAC properties – – – – Restoration of glutathione Reduction of fibroblasts Decreases ECM components Inhibition of proinflammatory & profibrotic cytokines and signal transducers – Improves lung function – Safe N-Acetyl Cysteine • • • • IFIGENIA trial 155 patients: NAC + Pred + AZA NAC titrated to 600mg t.i.d 1º endpoint at 12 months – 15% Δ VC – 20% Δ DLCO • Trend toward improved mortality Endothelin Receptor Antagonists • Rationale for use – Endothelin promotes expression of smooth muscle, fibrboblasts and ECM protein – Animal models • Endothelin levels elevated in IPF • Efficacy in pulmonary arterial hypertension • 3 drugs currently under evaluation – Bosentan – Sitaxsentan & Ambrisentan Bosentan • BUIILD 1 (IPF) – 132 patients, 32 centres, 9 countries – 1º endpoint at 12 months: 6 MWT – 2 º endpoint: mortality, lung function, QOL – Ongoing – Similar dose titration to PAH trials: 62.5125 bid The Evolution of IPF therapy • Steroids Azathioprine anti-oxidants anti-fibrotic ERA’s,anti-TNF ?????? 1950s 2004 Summary: What should we do now? • No FDA therapy approved for IPF – Multimodality therapy ? • Supplementary oxygen • Pulmonary rehabilitation • Patient with EARLY disease – Combination therapy • Prednisolone and Azathioprine (or Cyclophosphamide) – Experimental therapy in a RCT • Patient with LATE disease – Lung transplantation – Experimental therapy in a RCT