Patients with systemic autoimmune rheumatic disease–associated progressive pulmonary fibrosis (SARD-PPF) experience substantial lung function impairment and high risks of disease progression, hospitalization, and death or lung transplantation — regardless of the underlying autoimmune diagnosis, according to study results published in Arthritis & Rheumatology.
Researchers conducted a prospective, multicenter observational study and analyzed 585 patients with SARD-PPF enrolled in the US ILD-PRO Registry across 46 sites. Patients were aged 30 years and older and met established criteria for progressive fibrosing interstitial lung disease (ILD). Investigators evaluated baseline characteristics, treatment patterns, and clinical outcomes across seven SARD-ILD categories, including rheumatoid arthritis (RA), systemic sclerosis (SSc), idiopathic inflammatory myopathy, and Sjögren’s disease. Outcomes included ILD progression, respiratory hospitalization, death or lung transplant, and initiation of supplemental oxygen.
The total cohort included 585 patients (median age, 67.0 years; 65.6% women). Median forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLco) were 64.5% and 38.0% predicted, respectively. Over a median follow-up of 17.1 months, substantial risks of progression and adverse outcomes were observed. At 24 months, the probability of ILD progression ranged from 31.3% in myositis-associated ILD to 62.1% in RA-ILD. The highest probabilities of death or lung transplantation occurred in RA-ILD (37.6%) and interstitial pneumonia with autoimmune features (32.1%), compared with 9.3% in Sjögren’s disease–associated ILD.
These data provide contemporary real-world benchmarks and suggest that once progressive fibrosis is established, prognosis is influenced more by baseline severity and fibrotic disease behavior than by the underlying autoimmune diagnosis.
Unadjusted analyses identified significant differences in death or lung transplant risk across SARD subtypes, with lower risk in Sjögren’s disease-associated ILD versus RA-ILD (hazard ratio [HR], 0.28). However, these differences were no longer significant after adjustment for age or sex. No significant differences across subtypes were identified for ILD progression, respiratory hospitalization, or the composite outcome of supplemental oxygen initiation, hospitalization, transplant, or death.
Older age and lower baseline FVC independently predicted worse outcomes. Each 5-year increase in age was associated with a 15% higher risk of death or lung transplantation (HR, 1.15), while each 5-percentage-point increase in predicted FVC was associated with a 9% lower risk (HR, 0.91). White race was also associated with increased risk compared with non-White race (HR, 1.97).
Study limitations included modest subgroup sample sizes, heterogeneity within certain SARD-ILD classifications, and limited generalizability to community settings.
“These data provide contemporary real-world benchmarks and suggest that once progressive fibrosis is established, prognosis is influenced more by baseline severity and fibrotic disease behavior than by the underlying autoimmune diagnosis,” the study authors concluded.
This research was supported by Boehringer Ingelheim. Please see the original reference for a full list of disclosures.
