Restrictive: Idiopathic Pulmonary Fibrosis

Question 1

What is IPF?

Answer 1

Fibrosis (scarring) of lung interstitium

Etiology is unknown

Question 2

Explain the pathogenesis

Answer 2

Wall of alveolar sac interstitium becomes very thick - fibrosed

Repeated cycles of lung injury and wound healing with increased collagen deposition

Pathogenesis:
- Etiology is related to cyclical (recurrent cycles) lung injury

– resulting in cyclical healing

Key mediators in healing is: Cytokine TGF-Beta

• TGF-B from injured pneumocytes induces fibrosis
• Secondary causes for this fibrosis such as drugs (e.g. bleomycin and amiodarone) and radiation therapy must be EXCLUDED

Question 3

Explain the clinical features/signs for IPF

Answer 3

Can develop form 6 mths to several years
- Progressive dyspnoea – which gets worse over time because the fibrosis progresses over time

• Non-productive cough
• Digital clubbing
• Traction bronchiectasis - irreversible dilatation of bronchi and bronchioles
• Fine, dry, inspiratory crackles (Velcro crackles) at both bases

CT:
Fibrosis initially begins in subpleural region underneath pleura
- Progressing to involve whole lung with diffuse fibrosis everywhere known as ‘honeycomb’ lung

Question 4

What is the treatment IPF?

Answer 4

Lung transplantation -

As there’s no way of removing the fibrosis