Functional impact of Usual Interstitial Pneumonia pattern in Interstitial Lung Diseases

Abstract

Objective: To evaluate longitudinal changes in pulmonary function among patients with interstitial lung disease presenting the pattern of Usual Interstitial Pneumonia treated with antifibrotic agents. Secondary objectives involved comparing the evolution between idiopathic pulmonary fibrosis and non-IPF progressive fibrosing Interstitial Lung Diseases and assessing the prognostic value of the Gender, Age, Physiology score in relation to baseline functional parameters.

Methods: A retrospective observational study was conducted between June 2021 and September 2025 at the Pneumology Clinic of Mureș County Clinical Hospital that included 15 patients. Demographic data, high-resolution Computer Tomography findings, Forced Vital Capacity, Diffusing Capacity for Carbon Monoxide, and GAP scores were analyzed before and after treatment initiation. Data was assessed using Shapiro Wilk distribution test and paired t-tests.

Results: The study group consisted in 11 IPF and 4 non-IPF patients, with a mean baseline Gap score of 3.83±1.69. Under antifibrotic therapy, FVC showed numerical stabilization (83.50 ± 22.09% to 94.00 ± 16.09%; p = 0.94), while DLCO suggested a non-significant, controlled decline (43.86 ± 13.23% to 40.90 ± 16.15%; p = 0.26). IPF patients had greater baseline functional impairment and a more pronounced DLCO decline evolution. Gap score negatively correlated with baseline DLCO.

Conclusions: Nintedanib was associated with clinically relevant functional stabilization in UIP-pattern ILDs. Baseline functional impairment and the GAP score were revealed to be valuable variables in terms of risk stratification. Larger prospective studies are needed to confirm long-term outcomes.