Idiopathic Pulmonary Fibrosis

Question 1

what happens in IPF?

Answer 1

get scarring of the lungs with collagen deposition and honeycombing.

The lung tries to repair lung tissue by laying down scar tissue when it doesn’t need repaired

Question 2

who gets IPF?

Answer 2

more common in males and smokers

It is late onset

Question 3

what is the pathology of IPF?

Answer 3

chronic inflammatory infiltrate (neutrophils and fibrosis in alveolar walls or without intra-alveolar macrophages)

Question 4

why does IPF not respond to steroid treatment?

Answer 4

it is NOT an inflammatory disease

Question 5

what is the cause of IPF?

Answer 5

• as yet unknown -there is an imbalance in the fibrotic repair system
• could be related to gastric reflux, acid from the stomach causing damage

Question 6

what are other secondary causes of pulmonary fibrosis ?

Answer 6

• rheumatoid arthritis, SLE, systemic sclerosis, asbestos

- drugs: amiodarone, busulfan, bleomycin, penicillamine, nitrofuratoin, methotrexate

Question 7

what is the clinical presentation

Answer 7

• progressive breathlessness (several years) usually on exertion
• dry cough

Question 8

what would you find on examination?

Answer 8

• clubbing

- bilateral fine inspiratory crackles

Question 9

what do the fine inspiratory crackles suggest and why is this an issue?

Answer 9

• fine, inspiratory crackles and breathlessness means that a lot of people are referred to cardiology with heart failure but it is important to keep IPF on the differential diagnosis

Question 10

what investigations would be done?

Answer 10

• pulmonary function tests
• CXR
• CT scan
• Lung biopsy (this is not necessary is the CT scan is diagnostic)

Question 11

what would be found on pulmonary function tests?

Answer 11

• there would be a restrictive defect

- reduced FEV1 and FVC

Question 12

what would gas transfer be like?

Answer 12

low

Question 13

what would the CXR show?

Answer 13

bilateral infiltrates however the CXR may be normal in individuals with early or limited disease

Question 14

what would the CT scan show?

Answer 14

• reticulonodular fibrotic change which is worse at the lung bases
• the presence of ground glass suggests reversible alveolitis
• fibrosis is irreversible
• typically demonstrates a patchy, predominantly peripheral, subpleural and basal reticular pattern
• In more advanced disease: honeycombing cysts and traction bronchiectasis

Question 15

what should be on the differential diagnosis for this clinical presentation with investigations?

Answer 15

• exclude occupational disease (asbestosis, Silicosis)
• mitral valve disease - an echo is done to see if they have this
• left ventricular failure
• sarcoidosis
• extrinsic allergic alveolitis

Question 16

what treatment options are there?

Answer 16

-it is frustratingly ineffective
steroid and immunosuppressants do not change the course of disease

• N-acetyl cysteine may have anti-fibrotic effects via its antioxidant properties
• Pirfenidone is a new antifibrotic drug - only therapy shown in randomised controlled trials to slow down disease progression BUT very expensive
• Treatment is aimed at slowing future progression rather than reversing established fibrosis
• oxygen if hypoxic
• Pulmonary artery vasodilators - some patients with pulmonary fibrosis develop pulmonary hypertension
• Future treatments : other anti-fibrotic agents e.g. Tyrosine Kinase Inhibitors

Question 17

what is a potential treatment option for young patients?

Answer 17

lung transplant

Question 18

what is the prognosis like ?

Answer 18

most patients progress into respiratory failure and are dead within 5 years