Ideopathic Pulmonary Fibrosis

Question 1

What is Ideopathic pulmonary fibrosis?

Answer 1

Restrictive inflammatory lung disease:

• Inflammatory condition of the lung resulting in fibrosis of alveoli and interstitium

Question 2

What is the epidemiology of ideopathic pulmonary fibrosis?

Answer 2

• Rare: Prevalence in Uk is 6in100.000
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Question 3

What are risk factors for the development of ideopathic pulmonary fibrosis?

Answer 3

• Smoking
• Age
• FHx
• Gender. Men>Women
• Occupational exposure to metal
• Or wood (pine) –> aspiration

Question 4

What is the aetiology of ideopathic pulmonary fibrosis?

Answer 4

Ideopathic

• genetic predisposition
• might be exacerbated by occupational expsure e.g. inhalation of dust/irritants

Question 5

Explain the pathophysiology of idiopathic pulmonary fibrosis

Answer 5

• Damage to alveolar epthelial cells (e.g. due to surfactant mutation)
  
  • secretion of pro-inflammatory cytokines
  • attraction of other immune cells –> e.g. fibroblasts –> fibrosis
• Causing interstitial pneumonia

Question 6

What are the changes in insterstitial tissue in ideopathic pulmonary fibrosis?

Answer 6

Interstitial pneumonia and honeycombing

• Desquamative interstitial pneumonia (DIP: diffuse intra-alveolar accumulation of macrophages, mild thickening of alveolar septa, lymphoid aggregates)
• and non-specific interstitial pneumonia

Question 7

What are the presenting symptoms of someone with idiopathic pulmonary fibrosis?

Answer 7

• Progressive development of dyspnoea on exertion
• Progressive Dry cough, no wheeze
  
  • Might also cause systemic viral-like symptoms
  • Weight loss + fatigue are common

Question 8

What are the presenting signs of idiopathic pulmonary fibrosis?

Answer 8

• Clubbing
• Bibasal end-expiratory fine crackels
• In advanced stated: Findings for Cor-Pulmonale
• Tachypnoea with shallow breathing

Question 9

Which investigations would you consider in a patient with suspected idiopathic pulmonary fibrosis?

Answer 9

• Bloods
  
  • ABG: Normal in early disease, P02 low on exercise
  • RF and ANA (in 1/3)
• CXR
  
  • normal at presentation.
  • Early disease:
    
    • small lung fields
    • ‘ground glass’ shadowing.
  • Later:
    
    • reticulonodular shadowing (especially at bases),
    • signs of Cor pulmonale
    • very late: honeycombing
• If cannot be confirmed: CT
  
  • honeycombing
  • Traction bronchiectasis
  • lung architectural distortion, and
  • interlobular septal thickening
• Spirometry
  
  • Signs of restrictive lung disease
• Exclude other causes
  
  • Bronchoalveolar lavage
  • Biopsy to diagnose
  • Echo to look for Cor pulmonale