Idiopathic Pulmonary Fibrosis

Question 1

Idiopathic Pulmonary Fibrosis

Answer 1

a chronic progressive fibrotic interstitial lung disease of unknown cause which primarily occurs in older adults.

progressive pulmonary fibrosis with no clear cause.

Question 2

signs and symptoms of IPF

Answer 2

unexplained exertional dyspnoea (insidious onset) for more than 3 months.
dry chronic cough (no mucopurulent coughs)
clubbing
cyanosis
fatigue, lethargy
bibasal fine inspiratory crackles

Question 3

differential diagnosis of IPF

Answer 3

CHF, COPD

Question 4

pathophysiology of IPF

Answer 4

cause is unknown
risk factors - genetic issue with surfactant/telomerase
male, smoker, GORD, OSA, air pollution

recurrent micro-injuries to the epithelial and basement membrane > TNF alpha, IL1, and MCP -1 are released which activates resident fibroblasts and pro-fibrotic chemicals are secreted

fibroblasts activate
differentiate into myofibroblast - increase in collagen production (profibrotic event)

Question 5

investigations for IPF

Answer 5

bedside
blood
imaging:

CXR *lower lobe predominance
hazy opacities, bilateral reticular infiltrates, reduced inspiratory volumes

high res CT (gold standard) bilateral reticulation and honeycombing

special- pulmonary function test (reduced DLCO, reduced FVC, and low TLC).

Question 6

treatment of IPF

Answer 6

conservative
- smoking cessation
- annual vaccination
- pulmonary rehabilitation

medical
- pirfenidone (anti-fibrotic and anti inflammatory)
- nintedanib (monoclonal antibody targeting tyrosine kinase)

Question 7

drug induced pulmonary fibrosis

Answer 7

meds that can cause pulmonary fibrosis:

Amiodarone
Cyclophosphamide
Methotrexate
Nitrofurantoin

Question 8

secondary pulmonary fibrosis

Answer 8

Alpha-1 antitripsin deficiency
Rheumatoid arthritis
Systemic lupus erythematosus (SLE)
Systemic sclerosis

Question 9

interstitial lung disease

Answer 9

an umbrella term to describe conditions that affect the lung tissue (parenchyma) causing inflammation and fibrosis.

Question 10

how is ILD diagnosed?

Answer 10

imaging:
high rest CT scan of thorax
‘ground glass’ apperance

special:
biopsy for histology

Question 11

hypersenstivity pneumonitis (AKA extrinsic allergic alveolitis)

Answer 11

pathophysiology- type III hypersenstivity to an environemntal allergen. causes parenchymal inflammation.

investigation:
bronchoalveolar lavage (collect cells from the airways during bronchoscopy) and wash the airways with fluid = raised lymphocytes and mast cells

management:
remove allergen
oxygyen
steroids

Question 12

hypersenstivity pneumonitis (AKA extrinsic allergic alveolitis)

Answer 12

pathophysiology- type III hypersenstivity to an environemntal allergen. causes parenchymal inflammation.

investigation:
bronchoalveolar lavage (collect cells from the airways during bronchoscopy) and wash the airways with fluid = raised lymphocytes and mast cells

management:
remove allergen
oxygyen
steroids

Question 13

examples of specific cases of hypersensitivity pneumonitis

Answer 13

Bird-fanciers lung is a reaction to bird droppings
Farmers lung is a reaction to mouldy spores in hay
Mushroom workers’ lung is a reaction to specific mushroom antigens
Malt workers lung is a reaction to mould on barley