Interstitial lung diseasePaul Swift

What the?

1. Extrinsic Allergic alveolitis2. Idiopathic pulmonary fibrosis3. Industrial dust disease4. Organic dust disease5. Sarcoidosis

What’s important

PathophysiologyClinical features InvestigationManagementPrognosis

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

Investigation

Investigations1. Bedside

PEF (work v. home) ABG sats RR

2. Blood FBC, U&Es, LFTs, CRP, ESR ANA and Rf in IPF sometimes

3. Imaging CXR HRCT

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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, bronchoalveolar lavage

Lung function

Treatment

Conservative Weight loss Increased exercise Smoking cessation

Medical Oxygen Steroids

Surgical Transplant

Extrinsic allergic alveolitis

AKA- hypersensitivty penumonitisType III hypersensitivity reaction

Prior sensitisation to inhaled antigenExamples

1. Mould hay (farmer’s lung)2. Bird faeces (bird fancier’s lung)3. Cotton fibres (byssionosis)4. Sugar can fibres (bagassosis)

Famer’s lung

Bird fancier’s lung

EAA- why, why, why

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

Investigations

BedsideBloods

Neutrophil & leukocyte count IgG antibody titres

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

Treatment

Conservative Antigen avoidance!!!!

Medical: ?Corticosteroids Yup, severe disease Speed initial recovery

Prognosis Variable, depends on antigenavoidance

Idiopathic pulmonary fibrosis

AKA- Cryptogenic Fibrosing Alveolitis, Usual Intersitial Pneumonitis

Rare progressive chronic pulmonary fibrosis of unknown aetiology

Peak @ 45-65yrs

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

Clinical features

Same old SOB Dry cough Fatigue Can get considerable weight loss

More chronic/late stage Cyanosis Pulmonary hypertension/cor pulmonale Resp failure

Resp failure

On examination

O/E Clubbing

2/3!! Chest expansion reduced Fine-end inspiratory crackles

N/B. Associations

Investigations

Bedside ABG resp failure

Bloods Autoantibodies

ANA +ive in 1/3 Rf +ive in ½

Raised ESR

Investigations

Imaging CXR HRCT

Special Lung function BAL

Neutrophils Transbronchial or open lung biopsy for

histological diagnosis

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

Prognosis

50% 5 year survival

More dust disease

The pneumoconioses CABS

Coal Worker’s pneumoconiosis Asbestosis Berylliosis Silicosis

Group of disorders due to inhlation of mineral orbiological dusts

Coal Worker’s pneumoconiosis

Dose dependentSimple

Coal dust deposition in the lung Asymptomatic Diagnosis made by several small round opacities

on CXRCaplan’sSevere disease may progress to progressive

massive fibrosis

Progressive massive fibrosis

Large round fibrotic nodules >10mmUpper lobesScarringDyspnoea, cough, sputum

May be black if cavitating lesions

PMF

PMF treatment

Progresses when exposure removed Unlike simple

Prognosis is poor, no treatmentCoal Workers Pneumoconiosis Scheme

Pneumoconiosis Workers’ Compensation Act 1979 Lump sum compensation

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

Rx

No treatmentConsiderable time lag: 20-40 years following

exposureCompensationRisk……….

???

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

Sarcoid path

Non-caseating granulomas (Infiltrated by Th1 lymphocytes and

macrophages) (Fuse to multinucleated epithelioid cells)

Resolution of granulomas 10-20% persistent interstitial fibrosis

Clinical features

90% have pulmonary involvement SOB Chest pain Cough

Non-specific features Lymphadeopathy Weight loss Fever Fatigue

Extrapulmonary features

Inv

Bedside The usual

Bloods FBC (normochronic normocyctic anaemia) ESR Serum Ca2+ Serum ACE

Can be 2x normal levels Used to monitor progression

Imaging- CXR

More inv

Expensive stuff

HRCT Staging Identifying pulmonary fibrosis

Biopsy GOLD standard for diagnosis

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

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

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.

????

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?

Any questions