Idiopathic pulmonary fibrosis (IPF) is a chronic diffuse interstitial lung disease that is associated with the histologic appearance of usual interstitial pneumonitis (UIP).1
IPF, which is the most common idiopathic interstitial lung disease, has the worse prognosis, with a median survival of only 3 to 4 years.1–3
This grim prognosis rivals many cancers or disease due to HIV. IPF typically affects people between the age of 50 years and 70 years, and is noted worldwide without any clear ethnic predisposition. The estimated incidence of IPF in the United States is 7 to 11 cases per 100,000 each year.1
The characteristic histologic features of IPF include the following: (1) injury and activation of alveolar epithelial cells in an inhomogeneous subpleural distribution, (2) the distinctive presence of fibroblastic foci, and (3) exuberant extracellular matrix deposition. Although much has been learned recently about the pathogenesis of IPF, the etiology and precise cellular and molecular mechanisms involved are not established. Notably, no specific therapy has been proven unequivocally effective in IPF.4
Accordingly, it is not surprising that there is considerable controversy regarding various aspects of this disease.