L19 - Interstitial Lung disease

Question 1

Idiopathic pulmonary fibrosis

Answer 1

• normal areas of lungs punctuated by areas of marked fibrosis

Question 2

What will repetitive injury to alveolar epithelium result in..

Answer 2

Idiopathic Pulmonary Fibrosis

• wound healing mechanisms uncontrolled.
• overproduction fibroblasts
• increased deposition of ECM in interstitium with little inflammation
• loss of elasticity and ability to perform gas exchange of lung parenchyma

Question 3

Summarise specific ILDs

Answer 3

• Asbestosis
• hypersensitivity pneumonitis
• sarcoidosis
• idiopathic pulmonary fibrosis
• non-specific interstitial pneumonia

Question 4

Clinical features of IPF

Answer 4

• insidious onset of progressive dyspnoea accompanied by cough, with or without sputum production.
• honeycombing

Question 5

Hypersensitivity pneumonitis

Answer 5

• allergic reaction affectin the small airway and alveoli in response to inhaled antigen.
  e. g. mouldy hay, bird, mouldy cheese, mouldy grapes

Question 6

Pathogenesis of HSP

Answer 6

• chornic inflammatory infilitrate
• poorly desfined interstitial granuloma
• interstitial fibrosis
• honey comb change

Question 7

HSP on CXR

Answer 7

Increased reticular shadowing.

Diffuse small shadowing.

Question 8

Describe granulomatous lung disease

Answer 8

Granuloma is mainly composed of inflamed tissue by response of macrophage and histocyte to an inciting antigen.

Act of granuloma formation acts to confine a pathogen.

Question 9

Sarcoidosis

Answer 9

• multisystem granulomatous disorder

- characterised by tissue infiltration with non-caseating granulomas

Question 10

Describe the pathogenesis of sarcoid granulomas

Answer 10

non-necrotizing

Typical sarcoid granuloma consists of:
- accumulation of epitheloid cells, macrophages, lymphocytes.

Question 11

Describe extra pulmonary sarcoid

Answer 11

Sarcoidosis most frequently effects the lung.
- ILD, pneumothorax, PE, pulmonary hypertension.

Can present with extrathoracic manifestations esp. Skin, eyes and joints

Question 12

Why might hypercalcaemia arise from sarcoidosis?

Answer 12

• activated macrophages in lungs and lymph nodes are able to hydroxylate vitamin D directly
• leads to increased intestinal absorption of dietary calcium

Question 13

Asbestosis

Answer 13

Fibrosis of lung caused by asbestos dust.

Accompanised by breathlessness, finger clubbing and basal end inspiratory crackles.

Question 14

Symptoms of asbestosis

Answer 14

• insidious onset of breathlessness with exertion.

Question 15

Describe pathogenesis of acute hypersensitivity pneumonitis

Answer 15

antigen exposure leads to specific IgG antibodies.

Subsequent exposure to that antigen leads to lung inflammation.
neutrophil and immune complex formation

Question 16

Describe pathogenesis of chronic hypersensitivity pneumonitis

Answer 16

CD4+ Th1 lymphocyte mediated delayed hypersensitivity reaction
- granuloma formation

Question 17

Management of IPF

Answer 17

Anti-fibrotic therapy: pirfenidone

Lung transplantation

Question 18

Describe non-specific interstitial pneumonia

Answer 18

• chronic IIP characterised by homogenous appearance of dense interstitial fibrosis with mild to moderate chronic interstitial inflammation.