Host-environment interactions in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive scarring disease of the pulmonary parenchyma, leading to respiratory failure and death. Several epidemiological and theoretical observations link the pathogenesis of this disease to environmental injury to the lungs. We discuss the theoretical framework of this hypothesis and we present data in support of the concept that genetic and nongenetic host susceptibility may interact with repetitive environmental injury to lead to IPF.