The role of genetics and cigarette smoking in the development of pulmonary fibrosis

Several lines of evidence suggest that genetic factors and environmental exposure play a role in the development of pulmonary fibrosis. The authors evaluated families with familial pulmonary fibrosis (FPF), defined as the presence of two or more cases of idiopathic interstitial pneumonia (IIP) in first degree family members. In total, 56 families with FPF were evaluated with 193 affected and 196 unaffected individuals. The presence of FPF was based on clinical history, DLCO, and CXR in 27 (14%); clinical history and HRCT scan in 102 (53%); clinical history and SLB in 55 (28%); and clinical history and autopsy in nine (5%). Older age (67.8 vs. 53.6;  < 0.001), male gender (48% vs. 34%;  = 0.004), and cigarette smoking (59% vs. 36%;  < 0.0001) were associated with the development of FPF. Of 237 subjects self‐reported as unaffected, 10 had probable or definite FPF, and 23 had possible FPF. Evidence for aggregation of disease was highly significant ( < 0.001) among sibling pairs. Several pedigrees demonstrated vertical transmission, consistent with autosomal dominant inheritance. More than 50% of pedigrees demonstrated phenotypic heterogeneity, with several subtypes of IIP occurring within families. These findings indicate that FPF is caused by an interaction between cigarette smoking and a gene (or genes) that predisposes to the development of pulmonary fibrosis.

Duke Scholars

Author Holman Page McAdams Radiology, Cardiothoracic Imaging