Factors associated with rapid progression in fibrotic interstitial lung disease

Background: Early identification of fibrotic interstitial lung disease (F-ILD) patients with high risk of progression will help initiate early therapeutic intervention and potential improvement of outcomes. This study was designed to assess the predictors of progression in patients with F-ILD.Methods: Patients with F-ILD in Shanghai Pulmonary Hospital between January 1, 2019 and July 31, 2021 were retrospectively analyzed. The patients enrolled were divided into progressive group and non-progressive group according to the specified criteria. Baseline characteristics were collected and a multivariate regression was conducted to identify independent predictors of progression.Results: Of the 177 F-ILD cases, 87 were enrolled in the progressive group and 90 were in the non progressive group. The cohort included 11 types of F-ILD, primarily were connective tissue disease-associated interstitial lung disease (CTD-ILD) (43, 24.3 %), idiopathic pulmonary fibrosis (IPF) (39, 22.0 %), interstitial pneumonia with autoimmune features (IPAF) (32, 18.1 %), and unclassifiable (23, 13.0 %). The highest proportion of progression was seen in nonspecific interstitial pneumonia (NSIP) subgroup (66.7 %), followed by IPF (59.0 %) and HP (57.1 %). After adjusting for gender and age, a course of disease longer than 9.5 months (OR: 2.633; 95 % CI: 1.190-5.826, P = 0.017), lymphocyte in peripheral blood more than 2.24 (109/L) (OR: 2.670; 95 % CI: 1.095-6.510, P = 0.031), and emphysema in high-resolution computed tomography (HRCT) (OR: 2.387; 95 % CI: 1.017-5.640, P = 0.046) were independent predictors of progression in F-ILD patients.Conclusions: This study suggested that in patients with F-ILD, long course of disease, elevated blood lymphocyte and emphysema on HRCT were independent predictors of progression, which may suggest utility in early therapeutic intervention.