Transcript ILD-lecture
Interstitial and Occupational Lung Disease Dr Robin Smith Dept of Respiratory Medicine Interstitial Disease • Any disease process affecting lung interstitium (ie alveoli, terminal bronchi). • Interferes with gas transfer • Restrictive lung pattern (may also have some airway obstruction if small airways involved) • Symptoms: breathlessness, dry cough Interstitial Lung Disease Classification • Acute • Episodic • Chronic - part of systemic disease - exposure to agent (e.g. drug, dust etc) - idiopathic Acute ILD • Infection • Allergy • Toxins - usually viral - eg drug reaction - cytotoxic drugs, toxic fumes e.g. chlorine • Vasculitis - eg Wegener’s granulomatosis, Churg-strauss, SLE, Goodpasture’s syndrome • ARDS - trauma, sepsis Episodic ILD • • • • Pulmonary eosinophilia Vasculitis (Churg-Strauss, Wegener’s, SLE) Extrinsic Allergic Alveolitis Cryptogenic Organising Pneumonia Chronic ILD as part of systemic disease • Connective Tissue Disease (eg Rheumatoid arthritis, SLE, Systemic Sclerosis, Ankylosing Spondylosis) • Vasculitis (Churg-Strauss, Wegener’s, SLE) • Sarcoidosis • Cancer (lymphoma, lymphangitis carcinomatosis) • Miscellaneous - tuberose sclerosis, lipid storage disorders, neurofibromatosis, amyloidosis, miliary TB, bone marrow transplant) Chronic ILD - exposure to foreign agent • Fibrogenic inorganic dusts - coal, silica, asbestos, aluminium, • Non-fibrogenic dust - siderosis (iron), stannosis (tin), baritosis (barium) • Granulomatous/fibrogenic - berylliosis • Organic dusts - Farmer’s lung (Microsporylium), bagassosis (mouldy sugar cane), Bird fancier’s lung (feather and dropping antigen) Chronic ILD - idiopathic • Idiopathic Pulmonary Fibrosis (IPF) – also known as Cryptogenic fibrosing alveolitis (CFA) • Cryptogenic organising pneumonia (COP) • Sarcoidosis • Alveolar proteinosis • Lymphangioleiomyomatosis (LAM) • many other rarer causes SARCOIDOSIS • Multiple-system disease: common - lungs, lymph nodes, joints, liver, skin, eyes less common - kidneys, brain, nerves, heart • non-caseating granuloma of unknown aetiology: probable infective agent in susceptible individual. Imbalance of immune system with type 4 (cell mediated) hypersensitivity Types • Acute sarcoidosis: erythema nodosum, bilateral hilar lymphadenopathy, arthritis, uveitis, parotitis, fever. • Chronic sarcoidosis: lung infiltrates (alveolitis), skin infiltrations, peripheral lymphadenopathy, myocardial, neurological, hepatitis, splenomegaly, hypercalcaemia. SARCOIDOSIS Differential diagnosis = TB (tuberculin test -ve), Lymphoma, Carcinoma, fungal infection. • • Chest X-ray (BHL), CT scan of lungs (peripheral nodular infiltrate) Tissue biopsy (eg transbronchial, skin, lymph node) non-caseating granuloma. • • Pulmonary function: Restrictive defect due to lung infiltrates. Blood test: Angiotensin Converting Enzyme (ACE) activity marker (NOT diagnostic test). - raised calcium - increased inflammitory markers levels • Acute: self-limiting condition. • Chronic: oral steroids if vital organ affected (eg lung, eyes, heart, brain). as SARCOIDOSIS Treatment • Acute: self-limiting condition - usually no treatment Steroids if vital organ affected (eg impaired lung function, heart, eyes, brain, kidneys) • Chronic: oral steroids usually needed Immunosuppression (eg azathioprine, methotrexate) monitor chest X-ray and pulmonary function for several years often relapses Erythema Nodosum-Sarcoidosis Iritis due to sarcoidosis Bilateral hilar lymphadenopathy and lung infiltrares -Sarcoidosis EXTRINSIC ALLERGIC ALVEOLITIS I • Type III hypersensitivity (Immune complex deposition) reaction to antigen lymphocytic alveolitis (hypersensitivity pneumonitis). • Aetiology: Microsporylium (farmers lung, malt workers, mushroom workers), avian antigens (bird fanciers lung), drugs (gold, bleomycin, sulphasalazine) • Can be ACUTE or CHRONIC • ACUTE: cough, breathless, fever, myalgia - several hours after acute exposure (flu-like illness) Signs: +/- pyrexia, crackles (no wheeze!), hypoxia CxR: widespread pulmonary infiltrates Treatment: oxygen, steroid and antigen avoidance EXTRINSIC ALLERGIC ALVEOLITIS II CHRONIC: repeated low dose antigen exposure over time progressive breathlessness and cough • Signs: may be crackles, clubbing is unusual • CxR pulmonary fibrosis - most commonly in the upper zones • PFTs: restrictive defect (low FEV1 & FVC, high or normal ratio, low gas transfer - TLCO) • Diagnosis: history of exposure, precipitins (IgG antibodies to guilty antigen), lung biopsy if in doubt. • Treatment: remove antigen exposure, oral steroids if breathless or low gas transfer. Extrinsic allergic alveolitis[Avian] IDIOPATHIC PULMONARY FIBROSIS (also known as Cryptogenic Fibrosing Alveolitis) Most common interstitial lung disease • Clinical presentation: progressive breathlessness, dry cough OE: clubbing, bilateral fine inspiratory crackles, Ix: restrictive defect (reduced FEV1 and FVC with normal or raised FEV1/FVC ratio, reduced lung volumes, low gas transfer CxR - bilateral infiltrates; CT scan - reticulonodular fibrotic change, worse at the lung bases. The presence of “ground-glass” suggests reversible alveolitis; fibrosis is irreversible. • Causes: amiodarone, methotrexate). Primary (Idiopathic) Secondary (eg rheumatoid, SLE, systemic sclerosis, drugs busulphan, bleomycin, penicillamine, nitrofurantoin, IDIOPATHIC PULMONARY FIBROSIS II • Differential diagnosis = exclude occupational disease (asbestosis, silicosis), mitral valve disease, left ventricular failure, sarcoidosis, extrinsic allergic alveolitis. • Ask about occupation (in depth), pets and drugs • Diagnosis: combination of history, examination and radiology tests • If the presentation is atypical then lung biopsy (either transbronchial or thoracascopic) is needed • Pathology: chronic inflammatory infiltrate (neutrophils and fibrosis in alveolar walls ± intra-alveolar macrophages. IDIOPATHIC PULMONARY FIBROSIS III • Treatment: not clear if influences course of disease oral steroids ± immunosuppressive drugs (eg azathioprine combined with Nacetyly cisteine) worth trying if patient is <75 years and evidence of acute inflammation on CT scan - some response in 30%. NB treatment is aimed as slowing future progression rather than reversing established fibrosis. Oxygen if hypoxic. Lung transplantation in young patients Future treatments: ?Anti-fibrotic agents ?anti-TNFα pulmonary artery vasodilators • Prognosis: most patients progress into respiratory failure and are dead within 5 years DIP-pre steroids Fibrosing Alveolitis Lymphocytic alveolitis and intralumenal macrophages COAL WORKERS PNEUMOCONIOSIS • Simple pneumoconiosis - chest X-ray abnormality only (no impairment of lung function - often associated with chronic obstructive pulmonary disease). • Complicated pneumoconiosis - progressive massive fibrosis restrictive pattern with breathlessness. • Chronic bronchitis (coal dust + smoking). • Caplan’s syndrome (pulmonary nodules). - rheumatoid pneumoconiosis SILICOSIS • 15-20 years exposure to quartz (eg mining, foundry workers, glass workers, boiler workers). • Simple pneumoconiosis - chest X-ray abnormality only (egg-shell calcification of hilar nodes). • Chronic silicosis - restrictive pattern, pulmonary fibrosis. Coal workers progressive massive fibrosis Coal workers progressive massive fibrosis Baritosis ASBESTOS-related lung disorders • Mining, construction, shipbuilding, boilers and piping, automotive components (eg brake linings). • Pleural disease 1- Benign pleural plaques - asymptomatic 2- Acute asbestos pleuritis - fever, pain, bloody pleural effusion 3- Pleural Effusion and Diffuse pleural thickening - restrictive impairment 4- Malignant Mesothelioma - incurable pleural cancer. Presents with chest pain and pleural effusion. No available treatment - fatal within two years. • Pulmonary Fibrosis - “Asbestosis” - heavy prolonged exposure. Diffuse pulmonary fibrosis and restrictive defect. Asbestos bodies in sputum. Asbestos fibres in lung biopsy. • Bronchial carcinoma - asbestos multiplies risk in smokers Asbestosis Asbestos pleural plaques and Bronchial Ca Pleural effusion due to mesothelioma OCCUPATIONAL ASTHMA • Sensitising agents - high molecular weight (eg bakers, enzymes, gums, latex) - low molecular weight (eg isocyanates, wood dust, glutaraldehyde, solder, flux, dye, adhesives, drugs). • Diagnosis: RAST test, provocation testing, PEFR at home/work. • Reactive airway dysfunction syndrome - acute episode of toxic gas or fume inhalation (eg chlorine or sulphur dioxide) followed by persistent bronchial hyperreactivity. Useful clinical & X-ray teaching sites hhhttp://www.radiology.co.uk/srs-x/index.htm guidelines) http://www.brit-thoracic.org.uk/clinical-information/interstitiallung-disease-(dpld)/interstitial-lung-disease-(dpld)guideline.aspx