Familial idiopathic pulmonary fibrosis: Clinical features and outcome

Study objectives: Familial idiopathic pulmonary fibrosis (FIPF) has been defined as idiopathic pulmonary fibrosis (IPF) occurring in two or more members of a family. The clinical course of FIPF has not been fully defined. Accordingly, the current study was undertaken to establish clinical, radiologic, and histologic features, and survival in a consecutive series of patients with FIPF. Design: Retrospective analysis of clinical, radiologic, and pathologic data from a consecutive series of patients with FIPF who were seen at Mayo Medical Center. Survival in patients with FIPF was contrasted to that of previously characterized patients with nonfamilial IPF who were evaluated at our institution. Setting: Tertiary referral medical center. Patients: We screened 47 patients and family members with FIPF from 15 families who were identified between the years 1992 and 2002. We further analyzed the subgroup of FIPF patients that was composed of 27 patients from 15 families in whom the complete clinical course was monitored at our institution. Measurements: All patients exhibited clinical features that were compatible with IPF and either compatible high-resolution CT (HRCT) scan findings or histologic evidence of usual interstitial pneumonia. Clinical data, including symptoms, physical findings, HRCT scan findings, lung function test results, biopsy results, and survival were abstracted from the clinical records. Results: Compared to patients with nonfamilial IPF, patients with FIPF did not demonstrate any notable differences in clinical, radiologic, or pathologic features. We observed that the total number of affected members in a family with FIPF was a significant risk factor for earlier mortality (p = 0.0157; hazard ratio, 1.434). Overall, however, patients with FIPF had a statistically similar outcome to those patients with nonfamilial IPF. Conclusions: Although uncommon, FIPF represents a distinct syndrome, which has clinical features and patient survival rates that are similar to those of nonfamilial IPF.