Idiopathic pulmonary fibrosis

The long-term outlook (prognosis) for people with idiopathic pulmonary fibrosis (IPF) is poor, with only 20-30% of affected people surviving at least 5 years after diagnosis. Several factors have been associated with a shortened survival time, including:^[1]

• older age at diagnosis
• extensive cigarette smoking
• lower body mass index (BMI)
• more severe physiologic impairment
• greater extent of disease on imaging studies
• the development of other complications or conditions (eg, pulmonary hypertension, emphysema, and bronchogenic cancer)

The natural history of IPF is not completely understood. While it usually follows a course of progressive deterioration, some people remain stable for extended periods and individual outcomes can vary significantly. Still, long-term survival of IPF is not expected.^[2]

It now appears that three potential disease courses exist, but there is not currently a definitive way to predict the course in an affected person. They are:^[2]
a) slowly progressive disease (the most common);
b) disease marked by episodes of acute exacerbations; and
c) rapidly progressive disease.

Lung transplantation for idiopathic pulmonary fibrosis (IPF) has been shown to have a survival benefit over medical therapy. IPF is now the most common indication for lung transplantation in the United States. Any person diagnosed with IPF should be referred for lung transplantation evaluation.^[3] A 2009 retrospective review of UNOS data found that the reported 5-year survival rates after lung transplantation in IPF were estimated at 50-56%.^[3] This is greater than the 20-30% general 5-year survival rate for affected people.

It is somewhat controversial whether people with IPF should have a single or bilateral lung transplant. Some have reported no difference in overall survival between the two types of transplants. Others have found a trend toward better early survival after a single transplant, and better long term survival after a bilateral transplant. It has now been seen in several studies that bilateral transplants may have better long-term outcomes, but worse short-term outcomes; single transplants have been associated with a slightly higher later risk of death.^[4]

Although the question of whether to perform a single or bilateral transplant remains unanswered, there is an increasing tendency in the transplant community to perform bilateral rather than single lung transplants. The data overall seem to suggest that although bilateral lung transplant may increase the risk for early death, it promotes long-term survival. It is possible that the early mortality caused by bilateral lung transplants has been improved by better surgical techniques and critical care.^[4]