Disease progression across the spectrum of idiopathic pulmonary fibrosis: A multicentre study

Background and objective: In clinical practice, a working diagnosis of IPF may be performed to provide effective antifibrotic treatment to patients who cannot undergo SLB. In this study, we compared the disease course across IPF diagnostic categories in a real-life clinical setting to clarify the appropriateness of a working diagnosis of IPF and treatment initiation in these patients. Methods: Longitudinal data from IPF patients receiving antifibrotic treatment (pirfenidone or nintedanib) were retrospectively collected at three tertiary centres in Italy. Univariate and multivariate analyses were performed to compare time to death and to a composite endpoint of disease progression between two diagnostic subgroups, that is, patients with UIP on HRCT and/or SLB, and patients with possible UIP and no histological confirmation. Results: A total of 249 IPF patients were included in the analysis. Among patients with a possible UIP pattern on HRCT, 41 (55%) were prescribed antifibrotic treatment (either nintedanib or pirfenidone) despite absence of histological confirmation. This group demonstrated similar mortality and disease progression as compared to patients with a definite diagnosis of IPF as per diagnostic guidelines (log-rank test P = 0.771 and P = 0.139, respectively). Such findings were confirmed on multivariate analysis (HR: 1.19, 95% CI: 0.49–2.89, P = 0.7 for death; HR: 1.42, 95% CI: 0.83–2.44, P = 0.201 for disease progression). Conclusion: In patients receiving antifibrotics following a working diagnosis of IPF, disease progression rates were similar to patients with a confident diagnosis of IPF according to consensus guidelines, supporting the rationale for treatment initiation in these patients by expert multidisciplinary teams.