Interstitial and Granulomatous Lung Disease

Question 1

What are the signs and symptoms of pulmonary fibrosis?

Answer 1

• Progressive breathlessness
• Hacking dry cough
• Fatigue
• Weakness
• Loss of appetite
• Weight loss
• Bibasilar crackles
• Clubbing
• Peripheral interstitial patterns
• Subpleural honeycombing

Question 2

What are the main causes of pulmonary fibrosis?

Answer 2

• Occupational and environmental (silicosis, asbestosis, hypersensitivity pneumonitis)
• Drug induced (amiodarone, nitrofurantoin, methotrexate, cocaine)
• Connective tissue diseases (lupus, RA, scleroderma)
• Primary diseases (sarcoidosis, LAM)
• Idiopathic (IPF, NSIP)
• Genetics

Question 3

How is pulmonary fibrosis diagnosed?

Answer 3

• HRCT (ground glass appearance)
• Clincal features
• Difficult cases involve the use histology from biopsy done using VATS procedude (80% of lung tissue should be space, in PF lots of extra pink material)

Question 4

What is the pathogenesis of IPF?

Answer 4

• Repetitive alveolar epithelial injury
• Altered alveolar microenvironment (affected by oxidative stress, profibrotic cytokines, TIMPS-MMPs imbalance, chemokines, impaired fibrinolysis and eicosanoid imbalance)
• Dysregulated repair, loss of epithelial cells and accumulation of mesenchymal cells
• Fibrosis

Question 5

What are the features of sarcoidosis?

Answer 5

• Non-necrotising granulomatous inflammation and asteroid bodies on histology
• Systemic symptoms in 45% of cases include fever, anorexia, fatigue, night sweats and weight loss
• Clinical signs include dyspnoea, cough, vague chest discomfort and wheezing

Question 6

How are CXRs classified in sarcoidosis?

Answer 6

• 1) Bilateral hilar lymphadenopathy without infiltration
• 2) Bilateral hilar lymphadenopathy with infiltration
• 3) Infiltration alone
• 4) Fibrotic bands, bullae, hilar retraction, bronchiectasis and diphragmatic tenting

NB - Histology is the gold standard for diagnosis of sarcoidosis - shows non-caseating granulomas with epithelioid cells.

Question 7

Management of interstitial lung disease

Answer 7

• Remove or treat the underlying cause
• Home oxygen where they are hypoxic at rest
• Stop smoking
• Physiotherapy and pulmonary rehabilitation
• Pneumococcal and flu vaccine
• Advanced care planning and palliative care where appropriate
• Lung transplant is an option but the risks and benefits need careful consideration
• In PF licenced medicaitons indclude:
  
  • Pirfenidone (antifibrotic and anti-inflammatory)
  • Nintedanib (monoclonal antibody targeting tyrosine kinase)

Question 8

What organs does sarcoidosis affect?

Answer 8

• From most to least common:
  
  • Lungs
  • Systemic symptoms
  • Liver
  • Eyes
  • Skin
  • Heart
  • Kidneys
  • CNS
  • PNS
  • Bones