Outcomes in Progressive Pulmonary Fibrosis in Systemic Autoimmune Rheumatic Diseases: Real-World Data from the ILD-PRO Registry.

OBJECTIVE:We evaluated baseline characteristics, treatment patterns, and outcomes in patients with systemic autoimmune rheumatic disease-associated progressive pulmonary fibrosis (SARD-PPF) and evaluated whether outcomes differed by SARD subtype. METHODS:The ILD-PRO Registry is a prospective multicenter US registry of patients with PPF. Eligible participants had an ILD other than idiopathic pulmonary fibrosis with reticulation and traction bronchiectasis on high-resolution computed tomography and/or lung biopsy, and met criteria for PPF within the prior 24 months. Among patients with SARD-PPF, we described baseline characteristics and evaluated associations between SARD subtype and clinical outcomes. RESULTS:Among 585 patients with SARD-PPF, physiologic impairment at enrollment was substantial (median FVC 64.5% predicted; median DLco 38.0% predicted); 39.2% used supplemental oxygen, 73.9% were receiving immunomodulatory therapy, and 22.6% were taking nintedanib. By 24 months, 31.3%-62.1% of patients experienced ILD progression across SARD subtypes, and 9.3%-37.6% experienced death or lung transplant. Rheumatoid arthritis-PPF showed the highest unadjusted probability of ILD progression; however, no significant subtype-associated differences were observed in analyses adjusted for age, sex, and/or baseline FVC % predicted. CONCLUSION:In a large prospective multicenter US cohort, SARD-PPF was characterized by advanced physiologic impairment, high treatment burden, and high risk for further progression and death or lung transplant. After accounting for demographic factors and baseline severity, outcomes were broadly similar across SARD diagnoses, supporting phenotype-focused risk stratification and underscoring the need for systematic monitoring and timely optimization of management for SARD-ILD.