Pulmonary Fibrosis

Question 1

What are the respiratory causes of clubbing?

Answer 1

1. Fibrosis (and TB)
2. Chronic suppurative lung disease (bronchiectasis; empyema; chronic abscess)
3. Lung cancel (not small cell: progresses too quickly)

Question 2

What are the causes if upper zone fibrosis?

Answer 2

Upper lobe (‘A TEA SHOP’)

ABPA

TB
Exrinsic allergic alveolitis
Ankylosing spondylosis

Sarcoid
Histiocytosis
Occupational
- Berylliosis, silicosis
Pneumoconiosis

Question 3

What are the causes of lower zone fibrosis?

Answer 3

Lower (‘BRAD’)

Bronchiectasis
RA (and other connective tissue disease)
Asbestos
Drug’s

Question 4

What is an exacerbation of fibrosis?

Answer 4

• An unexplained worsening or development of dyspnoea within 30 days with new radiological infiltrates on HRCT
• Poor prognosis
• Treatment is iv steroid as 1st line and other immunosuppressant (e.g. cyclophosphamide) as 2nd line

Question 5

What is hystiocytosis?

Answer 5

A multi-system disease with abnormal proliferation of histiocytes. Commonly affects young people.

• Respiratory
• Mixed obstructive and restrictive pattern
• Low KCO, low FEV1/FVC ratio
• Renal damage
• Skin
• 1-5mm papules
• Lymphadenopathy
• Bones
• Radiolucent skull lesions
• Marrow invasion

Question 6

What is the definition of pulmonary fibrosis?

Answer 6

The end-stage of many different pulmonary diseases. The lungs become fibrosed (thickened, stiff and scarred) and lack their usual elasticity and compliance. It can be localised (e.g. one lobe) or affect the whole lung

Question 7

What us the epidemiology if pulmonary fibrosis?

Answer 7

Idiopathic disease approximately 10 per 100,000 per year

Increases with age: peak incidence 50-70 year-olds

Question 8

What causes pulmonary fibrosis?

Answer 8

1. Usual interstitial pneumonia (UIP)
   - Also called Idiopathic Pulmonary Fibrosis (IPF) and Cryptogenic Fibrosing Alveolitis (CFA)
2. Rheumatological
   - Rheumatoid arthritis; SLE; dermatomyositis; polymyositis; mixed connective tissue disease; Sjogrens; anklylosing spondylitis; systemic sclerosis (CREST)
3. Occupational
   - Asbestosis
   - Silicosis
   - Beryliosis
   - Pneumoconiosis
   - Extrinsic Allergic Alveolitis (EAA)
4. Infection
   - Aspergillosis (ABPA)
   - TB
5. Drugs
   - Amiodarone
   - Methotrexate
   - Bleomycin
   - Cyclophosphamide
   - Nitrofurantoin
6. Vasculitis
   - Wegeners; Churg-strauss; Goodpastures
7. Radiation fibrosis
8. Aspiration
9. Sarcoid
10. Histiocytosis

Question 9

What is the presentation of pulmonary fibrosis?

Answer 9

Shortness of breath
Cough: usually non-productive
Haemoptysis
Chest pain
Wheeze

On examination:
Clubbing
Fine bilateral basal ‘velcro’ crackles
Signs of cor pulmonare (RV heave, peripheral oedema, raised JVP)
Signs of underlying cause (e.g. associated auto-immune disease)

Question 10

What are the main differentials of pulmonary fibrosis?

Answer 10

COPD (predominantly bronchitis)
Asthma
Heart failed

Question 11

What are the investigations did pulmonary fibrosis?

Answer 11

1. Bloods
FBC, U&E, LFT, CRP
ESR
Autoimmune profile
- RF; ANA; ANCA; anti-GBM
CK (raised in dermatomyositis)
ACE (may be raised in sarcoid)

2. ABG (Type 1 respiratory failure)
3. CXR
   Reduced volume and reticulonodular shadowing
   Honeycombing
4. Lung function tests
   Restrictive pattern (FEV1/FVC>70%)
   Low TLC
   Reduced KCO

5. High-resolution CT chest (HRCT)
Distribution of fibrosis to sub-pleural lung is typical of IPF/ UIP
Reticular opacities
Sub-pleural honeycombing
Traction bronchiectasis

6. Broncho-alveolar lavage (BAL) and biopsy
   Important as lymphocytes > neutrophils indicate a better response to steroids and a better prognosis

Question 12

What is the diagnostic criteria for Usual Interstitial Pneumonia (UIP) / Idiopathic Pulmonary Fibrosis (IPF)

Answer 12

1. Major Criteria
   Exclusion of other causes e.g. drug toxicities, connective tissue disease
   Abnormal pulmonary function studies (evidence of restriction)
   Bibasilar reticular abnormalities with minimal ground glass opacities on HRCT
   No evidence of alternative diagnosis on transbronchial biopsy or BAL

2. Minor Criteria
Age > 50
Insidious onset of otherwise unexplained dyspnoea on exertion
Duration > 3 months
Bibasilar inspiratory crackles

3. Usual interstitial pneumonia (UIP) is defined pathologically by a heterogenous appearance with alternating areas of normal lung, interstitial inflammation, fibrosis and honeycomb change affecting the peripheral supleural parenchyma most severely.

Question 13

What is the management of pulmonary fibrosis?

Answer 13

1. Medical
Prednisolone
Azathioprine and cyclophosphamide
Pirfenidone
- Licensed for use in patient with UIP with FEV 50-80% predicted (NICE guidelines)

2. Home oxygen
3. Pulmonary rehabilitation
4. Lung transplant
   * Indications:
   Age under 60 with expectancy under 18 months
   Match for ABO, not Rh
   Double transplant preferred
   Donor
   - Good cardiac and lung function, age under 40
   - Chest diameter slightly less than recipient

Question 14

What are the complications of pulmonary fibrosis?

Answer 14

Respiratory failure
Pulmonary hypertension
Pneumothorax
Increased risk of bronchogenic cancer

Question 15

What is the prognosis of pulmonary fibrosis?

Answer 15

Variable and depends on type

Highly cellular with ground glass infiltrate: good response to immunosuppression
- 80% 5 year survival

Honey-combing on CT and no response to immunosuppression
- 20% 5 year survival