Idiopathic Pulmonary Fibrosis

Question 1

IDIOPATHIC PULMONARY FIBROSIS

Answer 1

• Characterised by Diffuse Inflammation and
Fibrosis of Lung Parenchyma; Mean onset 60+,
More common in Males, relatively rare
• Unknown Aetiology – Possibly contributed by
Cigarette smoking, Chronic Aspiration,
Antidepressants, Dust and EBV infection;
Suggested due to repeated exogenous and
endogenous stimuli; Inflammation plays little
or no part in IPF
o Multiple Microinjuries to Alveolar cells
cause secretion of growth factors that
recruit and stimulate fibroblasts;
Differentiate into Myofibroblasts
• Patchy Fibrosis of the Interstitium; Acute
Fibroblastic proliferation, Collagen Deposition
and Honeycombing

Question 2

Presentation of Idiopathic Pulmonary Fibrosis

Answer 2

• Progressive Breathlessness, Non-productive Cough, Cyanosis leading to Respiratory Failure,
Pulmonary Hypertension and Cor Pulmonale; Fine Bilateral End Inspiratory Crackles, Gross
Finger Clubbing (two thirds of cases); Acute form (Hamman-Rich Syndrome)
• Various Autoimmune diseases including Coeliac, UC, as well as Renal Tubular Acidosis

Question 3

Management of Idiopathic Pulmonary Fibrosis

Answer 3

• CXR/High Res CT – Ground Glass appearance followed by irregular Reticulonodular Shadowing
(Maximal in Lower Zones) finally leading to Honeycomb Lung
• Respiratory Function Tests – Restrictive Ventilatory Defect; ↓TLC, High/Normal FEV1/FVC
ratio, Reduced CO transfer
• ABG – Hypoxaemia due to Alveolar-Capillary block
and V/Q Mismatch; Normal/Low PaCO2 due to
compensatory Hyperventilation
• ANA and RF positive in 1/3 of patients; ↑ESR and Ig
• Histology – Transbronchial Lung Biopsy, VATS Biopsy
• Treatment with Prednisolone (little benefit),
Azathioprine, Cyclophosphamide; Home Oxygen and
in severe disease in younger patients, Lung
Transplantation possible