Interstial Lung Disease

Question 1

What is the basic underlying pathology of interstitial lung disease?

Answer 1

Condition effecting of lung parenchyma which leads to inflammation and fibrosis= loss of normal elastic function of lungs

Remodelling and fibrosis of interstitium

Hyperplasia of type 2 epithelial cells and pneumocytes

Question 2

What are the 3 main classifications of interstitial lung disease?

Answer 2

1. Know cause
   - occupational or environmental= asbestosis/silicosis
   - drugs= bleomycin/amiodarone/cyclophosphamide/methotrexate/nitrofurantoin
   - hypersensitivity reactions
   - infections= TB/fungal
   - GORD
2. Associated systemic disease
   - Sarcoidosis
   - RA= important to check for signs of RA in hands of patient with lung disease
   - SLE
   - alpha-1 antitripsin deficiency
   - systemic scelrosis
   - UC
3. Idiopathic
   - progressive pulmonary fibrosis without clear cause

Question 3

How features might idiopathic pulmonary fibrosis present with?

Answer 3

Insidious onset of SOB w/ dry cough over the last 3 months

Adults 50+

Bibasal fine inspiratory crackles

Finger clubbing

Smoking history

Prior medication or irradiation

Occupational/environmental exposure

Extra-pulmonary symptoms
-IBD/malignancy/weakness/fever/pain

Question 4

What investigations would you do if you suspected someone had interstial lung disease?
How is ILD diagnosed?

Answer 4

Bloods
-looking for ANA/anti-CCP antibodies and RF interstial lung disease being related to RA/sclerosis and CTD i.e. AI conditions

CXR

Spirometry to assess for lung function

CT scan

Diagnosis:
Clinical features in combo with HRCT showing “ground glass appearance”
Restrictive pulmonary spirometry
(Can take biopsy to confirm diagnosis)

Question 5

How can you manage ILD?

Answer 5

Hard to manage due to damage being irreversible so management tends to be to stop further progression of disease

• remove or treat cause
• LTOT (long term oxygen therapy) when hypoxic at rest
• prednisolone
• immunosuppression
• anti-fibrotic agents i.e . Pirfenidone and nintedanib
• smoking cessation
• physiotherapy and pulmonary rehab
• pneumococcal and flu vaccines
• advanced care planning
• lung transplant if benefits > harms

Question 6

What is hypersensitivity pneumonitis and what can it also be known as?
How can it be diagnosed?
What are specific causes?

Answer 6

Type 3 hypersensitivity reaction to environmental allergens which causes parenchyma inflammation

Bronchoalveolar lavage= washes airways to collect cells to test for raised lymphocytes and mast cells

Extrinsic allergic alveolitis (EAA)

Bird-fanciers lung= bird dropping
Farmers lung= mouldy spores
Mushroom workers lung= mushroom antigens

Question 7

What problems are associated with asbestosis?

Answer 7

Lung fibrosis 
Pleural thickening 
Pleural plaques 
Adenocarcinoma 
Mesothelioma