Idiopathic Pulmonary Fibrosis

aka cryptogenic fibrosing alveolitis. Prevalence : 5 million worldwide and 200,000 in the US. It affects men and women (1 : 2) and there is some genetic predisposition (3% show familial clustering). There is also a strong association with (current or prior) cigarette smoking.

This is one of those diseases that does not have a real established cause (hence "idiopathic") or even a real cure ( this despite the fact that there are newer treatments and the usual corticosteroids and cytotoxic drugs given in such cases.) So what does a doctor really do ?

The chances of spotting this disease in its earlier stages seem scarce. Like most 'idiopathic' diseases - its diagnosis begins with exclusion. Till the disease is advanced the patient may only present with non-specific symptoms (dyspnea, dry cough) and signs (fine dry bibasilar inspiratory crackles aka Velcro crackles and clubbing). You order a CXR, a pulmonary function test and a HRCT. The HRCT especially is helpful in uncovering parenchymal disease and underlying carcinomas.

The confirmatory diagnostic test (in case of an indeterminate HRCT) remains a lung biopsy- that too an open surgery or video-assisted transthoracic surgery involving a multiple site biopsy - which in itself must be stressful to an already stressed patient.

What do I look for ?

1. CXR showing diffuse reticular basal and peripheral opacities, honeycombing and dilated airways d/t traction bronchiectasis.
2. Pulmonary spirometry showing restrictive pattern
3. HRCT confirming CXR findings plus showing irregularly thickened interlobular septa and intralobular lines.
4. Lung biopsy showing subpleural fibrosis, dense scarring and alternate areas of normal lung tissue & fibroblast proliferation foci. Peripheral cystic dilatations of alveoli (honeycombing) increase with advancing disease.

What can I offer the patient?

1. A mix of corticosteroids and cytotoxic drugs - with the doses regularly titrated depending on how the disease responds.
2. There are a couple of new drugs on the market : Antifibrotic drugs (Pirfenidone and others) and interferon-gamma- 1b have shown promise in certain settings but their true efficacy remains to be established.
3. End of life planning and discussion (median survival is less than 3 years from diagnosis.)

Lung transplant ? only possibly successful in an "otherwise healthy" subgroup of patients < 55 years of age with end stage pulmonary disease. (< 40% of the total IPF population.)

My source for the above info.