Prognostic Significance of Pathologically Proven Chronic Fibrosing Interstitial Lung Diseases with a Progressive Phenotype (Pf-Ilds): Single Center Retrospective Cohort

Background: “Progressive fibrosing ILDs (PF-ILDs)” is a practical emerging concept defined by the progressive disease behavior. Aims: Investigate the prevalence of the progressive phenotype in our consecutive database of pathologically proven interstitial lung diseases (ILDs), and the significance of prognosis. Methods: A progressive phenotype was defined by the criteria of the INBUILD trial (NEJM 2019). Consecutive cases with chronic fibrosing ILDs (pathologically proven and diagnosed by multi-disciplinary discussion) were registered from the recent database (Jan. 2010-Dec. 2016) of our hospital. Clinical data, and the survival were evaluated (Kaplan-Meier and Cox proportional hazards model). Results: We evaluated 144 consecutive cases including 34 cases with idiopathic pulmonary fibrosis (IPF), 32 cases with idiopathic interstitial pneumonias other than IPF (IIPs w/o IPF), 37 cases with chronic hypersensitivity pneumonitis (CHP), 14 cases with connective tissue disease-associated ILDs (CTD-ILDs), and 27 cases with other ILDs (Others). 87 cases (60.4%), including 22 IPF, 21 IIPs w/o IPF, 26 CHP, 7 CTD-ILDs, and 11 Others fulfilled the criteria of PF-ILDs. We didn9t find significant difference between diagnosis and PFILD (p=0.14). Three-year overall survival (OS) rate of all subjects were 87.7 %. Diagnosis didn9t statistically affect OS. In multivariate analysis, PF-ILD {HR 5.345 (95%CI, 1.001-98.94) , P=0.049}, DLCO in baseline (P=0.006) and gender (P=0.041) were significant factor. Conclusions: Diagnosis of PF-ILD may have prognostic significance in patients with pathologically proven cases with ILDs.