Interstitial Lung Disease
1. Definition: Heterogeneous group of diseases which affect the lung parenchyma (all lung tissuesbronchioles, bronchi, alveoli, interstitium) .
2. Characterised by: chronic inflammation and remodelling +/- progressive interstitial fibrosis,
hyperplasia of type II epithelial cells and pneumocytes.
3. Radiological changes keywords: ground-glass opacities/honeycombing/ streaky fibrosis, reticulonodular shadowing.
4. Classification: “Do you know what the cause is?”
 “NO”- IPF aka Cryptogenic Fibrosing Alveolitis
 “YES- SPECIFIC” :
(a) Drugs: Nitrofurantoin, Cytotoxics: Bleomycin/ Methotrexate, Sulfasalazine, Amiodarone (Refer:
http://www.pneumotox.com/pattern/view/8/I.g/pulmonary-fibrosis/)
(b) Infection: “TB is CRAP”- TB, Chlamydia Trachomatis, Respiratory Syncytial Virus, Atypical
Pneumonia, Pneuocystii Pneumonia)
(c) “A-CHOO!!!!”- Dusts!
Organic: Spores/proteins from birds/ malts/ mushrooms/ hot tubs/ cheese!
Industrial: Coal, Asbestos, Berryllium, Silicon
 “YES- SYSTEMIC”: RA, Sarcoidosis, UC, SLE, Sjogren’s, Renal Tubular Acidosis etc.
5. Signs & Symptoms:
 Progressive deterioration
 Dry, persistent cough
 Reduced exercise tolerance
 (effort dyspnoea)
 Drug history
 Occupational history
 Pets and hobbies
 An abnormal CXR
 Signs/symptoms of CT disease
6. Findings O/E:
 Dyspnoeic
 Clubbing/ Cyanosis
 Reduced expansion
 Deviated trachea- towards pathological side
 Dull percussion (localized)
 Fine end-inspiratory crackles
 Bronchial breathing (localized); Vesicular breathing (diffuse)
7. Investigations: BTS Guidelines very useful for all reps conditions!
 Urine dip (e.g. haematuria in RTA)
 FBC, U&E, LFTs
 Spirometry ( RESTRICTIVE DEFECT) and gas transfer (TLCO; <40% =advanced disease- consider
transplant!)
 CXR and HRCT (for those with normal CXR, thin slices 1-2mm at intervals 10-20mm)
 BAL (inflammatory cells/granulomas) and lung biopsy (before treatment- cancers)
 Other tests: sputum culture, ABG , CRP/ESR, BNP, RF/ anti-CCP, ANA, ANCA, Serum ACE;
Echocardiogram (RVF/Cardiomyopathy)
7. General management principles:
 Acute:ABCD and ? ABx if infective exacerbation
 Conservative: Lifestyle – exercise, weight loss, pulmonary rehab + Smoking cessation: up to 10fold increased risk of developing lung cancer
 LTOT: (BTS indications)
(a) PaO2 is ≤7.3 kPa (55 mmHg + clinical stability. Clinical stability = absence of exacerbation of
chronic lung disease for the previous five weeks.)
(b) PaO2 between 7.3 kPa and 8 kPa, together with : Secondary polycythaemia / Clinical and or
echocardiographic evidence of pulmonary hypertension
(c) PaO2> 8kPa : NIL LTOT
8. IPF: Dx of exclusion, unknown aetiology
 Pathogenesis: Soluble immune complexes + sensitized T lymphocytes activate macrophages
+ alveoli epithelial cells growth factor initiations Type 1+3 collagen deposits
 Radiologically: bi-basal, peripheral reticulo-nodular opacities, traction bronchiectasis and
honeycombing. (Rarely GGO)
 HRCT: Usual Interstitial Pneumonia =subpleural basal predominance, reticular pattern,
honeycombing, absence of micronodules/cysts
 Histology- (a) Cell infiltration: T lymphocytes + plasma cells Fibrosis + (b) Alveolitis:
Increased macrophages/ Type II Pneumocytes in alveolar space
 Rx: Supportive; Transplant; N-acetylcysteine+ Azathioprine + Prednisolone (small evidence
of success)
 Prognosis: Poor, 2-5yrs, complicated by bronchogenic Ca, death by T1RF
9. Occupational Lung Disease: HP aka EAA
 dust particles reach the terminal airways and epithelial lining  inflammatory reaction  scarring +
fibrosis
 Type 3 Hypersensitivity Reaction (Neutrophils+Complement Pathway)
 Acute: alveolar infiltration with inflammatory cells; Chronic: granuloma+obliterative bronchiolitis
 Symptoms start 4-6 hours after exposure to the antigen (may resolve and demonstrate cyclical
pattern according to daily routine)
 Measure serum preciptins: IgG
 Histology: lymphocytes and non-caseating granulomas, bronchocentric
 Radiology- upper zone fluffy nodular shadows, mid-zone mottling/consolidation, rarely hilar
lymphadenopathy, honeycombing
 Flu-like Sx: fevers, rigors, myalgia, weight loss, (later) cor pulmonale symptoms + T1RF
 Rx: it is reversible if diagnosed early: Acute: Remove allergen/ PPE, O2 therapy, oral prednisolone
(40mg/24hr- then reduce); Chronic: Avoid exposure (face masks), long term steroids (high dose
Prednisolone 30-60mg OD
 Industrial Dusts: CABS; Eligible for compensation through Industrial Injuries Act 1965
 NB: Malignant Mesothelioma with Asbestosis/ Asbestos Exposure
10. Sarcoidosis:
 Multi-system granulomatous disease of unknown aetiology
 Age 20-40yo, Afro-Caribbeans
 Erythema nodosum/ uveitis/ keratoconjunctivitis sicca/ hepatosplenomegaly/ dysrhythmias/ CCF/
arthralgia/ polyneuropathy/ meningoencephalitis
 Rx: acute NSAIDs, can recover spontaneously
 Steroids if symptomatic or static parenchymal disease, uveitis, hypercalcaemia, neurological or
cardiac involvement
 Prognosis: 60% thoracic involvement have spontaneous resolution, 20% respond to steroids
11. Further reading:
 BTS: http://www.brit-thoracic.org.uk/guidelines-and-quality-standards/interstitial-lung-diseaseguidelines/
 Kumar and Clark page 935-947
 Pnumotox: http://www.pneumotox.com/pattern/view/8/I.g/pulmonary-fibrosis/
 OHCM (Pages depending on edition)
 Radiology Masterclass: http://www.radiologymasterclass.co.uk/tutorials/tutorials.html (Revision on
radiology images)
GOOD LUCK!
Prepared by Rachel Cheong & Grace Pink