A cohort of patients with a progressive fibrosing phenotype of interstitial lung disease (PF-ILD) other than idiopathic pulmonary fibrosis (IPF): the PROGRESS study

Aim: This retrospective, monocentric cohort study aimed at assessing clinical characteristics, lung function course and overall survival of patients with non-IPF PF-ILD in a real-world setting. Methods: All successive patients hospitalized in a French Rare Lung Disease Reference Centre between 2010 and 2017, aged ≥18 years, with at least 10% fibrosis extent at baseline high resolution computed tomography of chest (HRCT) were included. PF-ILD over a period of 2 years was defined as: relative decline in forced vital capacity (FVC) ≥ 10% with or without clinical deterioration (a); or a moderate relative decline between 5% and 10% associated with worsening respiratory symptoms or increased extent of fibrosis in HRCT (b); or increased extent of fibrosis on HRCT with worsening respiratory symptoms with or without FVC decline (c). Results: 165 patients (57% of women) were included with a mean age of 60 (±14 years). Most of patients (65%) were included with criterion (a), 24% with criterion (b) and 9% with criterion (c). Estimates of overall survival were 99%, 82%, and 66% at 1, 3 and 6 years, respectively. Mortality was significantly associated with FVC Conclusion: The natural history of non-IPF ILD in patients with PF phenotype follows a course characterized by worsening of respiratory symptoms, progressive lung function decline and early mortality despite appropriate management.