Idiopathic pulmonary fibrosis (IPF) is the most common and severe form of interstitial lung disease (ILD). Although relatives of patients with familial pulmonary fibrosis (FPF) are at an increased risk for ILD, the risk among relatives of sporadic IPF is not known.
Undiagnosed first-degree relatives of patients with pulmonary fibrosis (PF) consented to participate in a screening study that included the completion of questionnaires, chest computed tomography, pulmonary function testing, a blood sample collection for immunophenotyping, telomere length assessments, and genetic testing.
Of the 105 relatives in the study, 33 (31%) had ILA, whereas 72 (69%) were either indeterminate or had no ILA. Of the 33 relatives with ILA, 19 (58%) had further evidence for ILD. There was no evidence in multivariable analyses that the prevalence of either ILA or ILD differed between the 46 relatives with FPF and the 59 relatives with sporadic IPF. Relatives with decrements in either total lung or diffusion capacity had a greater than 9-fold increase in their odds of having ILA (odds ratio, 9.6; 95% confidence interval, 3.1–29.8; P < 0.001).
Our findings suggest that screening for PF in relatives might be warranted.