Interstitial lung disease

1. Interstitial lung disease Paul Swift

2. What the? • Extrinsic Allergic alveolitis • Idiopathic pulmonary fibrosis • Industrial dust disease • Organic dust disease • Sarcoidosis

3. What’s important • Pathophysiology • Clinical features • Investigation • Management • Prognosis

4. Expaaaaand • Pathophysiology • Varies: inflammation  scarring  fibrosis • Presentation • Variation on a theme • SOBOE, lethargy, dry cough • SMOKING, PETS, OCCUPATION • O/E • Tachypnoea, clubbing • Cyanosis • Fine end inspiratory creps

5. Investigation • Investigations • Bedside • PEF (work v. home) • ABG  sats • RR • Blood • FBC, U&Es, LFTs, CRP, ESR • ANA and Rf in IPF sometimes • Imaging • CXR • HRCT

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8. Special tests • Lung function tests • Restrictive defect • FVC is reduced • FEV1 is reduced in proportion or slightly less • FEV1:FVC ratio normal or raised • TLCO the key! • Thickened fibrotic alveolar walls  shit for gas transfer • Others: Bronchoscopy, bronchoalveolarlavage

9. Lung function

10. Treatment • Conservative • Weight loss • Increased exercise • Smoking cessation • Medical • Oxygen • Steroids • Surgical • Transplant

11. Extrinsic allergic alveolitis • AKA- hypersensitivtypenumonitis • Type III hypersensitivity reaction • Prior sensitisation to inhaled antigen • Examples • Mould hay (farmer’s lung) • Bird faeces (bird fancier’s lung) • Cotton fibres (byssionosis) • Sugar can fibres (bagassosis)

12. Famer’s lung

13. Bird fancier’s lung

14. EAA- why, why, why

15. Clinical features • Standard stuff • Cough • SOB • Fever • Malaise • Acute onset hours after exposure • More insidious if long-term exposure to small amounts • O/E: Coarse end inspiratory crackles- upper lung • http://www.youtube.com/watch?v=HTNo_ovhcv8

16. Investigations • Bedside • Bloods • Neutrophil & leukocyte count • IgG antibody titres

17. Investigations • Imaging • CXR • Often normal in acute form • Subacute- reticular nodular Shadowing • Chronic- fibrosis with volume loss • HRCT • Special • Lung function • Bronchoalveolar lavage • Hisolopathological diagnosis

18. Treatment • Conservative • Antigen avoidance!!!! • Medical: ?Corticosteroids • Yup, severe disease • Speed initial recovery • Prognosis • Variable, depends on antigen avoidance

19. Idiopathic pulmonary fibrosis • AKA- Cryptogenic FibrosingAlveolitis, Usual Intersitial Pneumonitis • Rare progressive chronic pulmonary fibrosis of unknown aetiology • Peak @ 45-65yrs

20. IPF- patho • Alveolar walls thickened because of fibrosis • Predominantly lower lobes • Number of chronic inflammatory cells in alveoli and interstitium • Usual interstitial pneumonitis • Other patterns: • Desquamative interstitial pneumonitis • Bronchiolitis obliterans

21. Clinical features • Same old • SOB • Dry cough • Fatigue • Can get considerable weight loss • More chronic/late stage • Cyanosis • Pulmonary hypertension/corpulmonale • Resp failure

22. Resp failure

23. On examination • O/E • Clubbing • 2/3!! • Chest expansion reduced • Fine-end inspiratory crackles • N/B. Associations

24. Investigations • Bedside • ABG  resp failure • Bloods • Autoantibodies • ANA +ive in 1/3 • Rf +ive in ½ • Raised ESR

25. Investigations • Imaging • CXR • HRCT • Special • Lung function • BAL • Neutrophils • Transbronchial or open lung biopsy for histological diagnosis

26. Treatment • Conservative • Stop smoking • Weight Exercise • Medical • 50% respond to immunosuppression with combo therapy recommended: • Prednisolone 0.5mg/kg 1/12 • Azathioprine 2-3mg/kg • (can sub in cyclophosphamide for azathioprine) • Oxygen • Surgical • Transplant

27. Prognosis • 50% 5 year survival

28. More dust disease • The pneumoconioses • CABS • Coal Worker’s pneumoconiosis • Asbestosis • Berylliosis • Silicosis • Group of disorders due to inhlationof mineral or biological dusts

29. Coal Worker’s pneumoconiosis • Dose dependent • Simple • Coal dust deposition in the lung • Asymptomatic • Diagnosis made by several small round opacities on CXR • Caplan’s • Severe disease may progress to progressive massive fibrosis

30. Progressive massive fibrosis • Large round fibrotic nodules >10mm • Upper lobes • Scarring • Dyspnoea, cough, sputum • May be black if cavitating lesions

31. PMF

32. PMF treatment • Progresses when exposure removed • Unlike simple • Prognosis is poor, no treatment • Coal Workers Pneumoconiosis Scheme • Pneumoconiosis Workers’ Compensation Act 1979 • Lump sum compensation

33. Asbestosis • Inhlation of asbestos • Plumbers, electricians, builders • Blue asbestos (crocidolite) • Can’t be cleared by immune system • Histology: asbestos bodies and features of pulmonary fibrosis, affecting lower lobes more

34. Rx • No treatment • Considerable time lag: 20-40 years following exposure • Compensation • Risk……….

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36. Sarcoidosis • A 25-year old afro-Caribbean woman presents with SOB and bilateral leg lesions…… • Multisystem granulomatous disorder of unknown aetiology • Commonly effects the lungs • Non-caseating granulomas • Rare (19/100000 in UK) • Peak 20-40yrs

37. Sarcoid path • Non-caseating granulomas • (Infiltrated by Th1 lymphocytes and macrophages) • (Fuse to multinucleated epithelioid cells) • Resolution of granulomas • 10-20% persistent  interstitial fibrosis

38. Clinical features • 90% have pulmonary involvement • SOB • Chest pain • Cough • Non-specific features • Lymphadeopathy • Weight loss • Fever • Fatigue

39. Extrapulmonary features

40. Inv • Bedside • The usual • Bloods • FBC (normochronicnormocycticanaemia) • ESR • Serum Ca2+ • Serum ACE • Can be 2x normal levels • Used to monitor progression • Imaging- CXR

41. More inv

42. Expensive stuff • HRCT • Staging • Identifying pulmonary fibrosis • Biopsy • GOLD standard for diagnosis

43. Rx • Hilar lymphadenopathy and no pulmonary involvement = no treatment • Medical • Infiltration > 6weeks = steroids • Prognosis • Depends on stage • Mortality < 5% UK • Shadowing on CXR >2 years  risk pulm fibrosis

44. Summary • Pathogenesis • Varied but endstage is fibrosis and inflammation of the alveoli and interstitium • Presentation • Cough, SOB, fine end inspiratory crackles • Smoking, occupation, pets • Investigations • Bed, blood, imaging, special • Lung function- restrictive • CT- honeycombing, groundglass • Treatment • Steroids, transplant, avoid exposure

45. Case study A 64 year old gentleman presents to his GP with increasing SOB over the last 6 months. His exercise tolerance has reduced to the point where walking to the corner shop makes him out of breath. He also complains of a dry cough. He has a past medical history of high blood pressure which is managed with Ramipril. He has never smoked and works as an office manager. On examination he is slightly short of breath with O2 sats 93% on air and he has clubbing. Auscultation reveals bilateral basal fine end inspiratory crepitations and no wheeze.

46. ???? • What are your main differential diagnoses for this gentleman? (make sure these include all important differentials that must be ruled out) • How would you investigate this gentleman? • What is your management plan? Will anything help? • Can you tell me about the pathophysiology of ILD? • Can you tell me some causative organisms for EAA?

47. Any questions