Lung Transplantation in Rheumatoid Arthritis Related Interstitial Lung Disease: Risk Factors and Mortality in a Universal Health Care System.

BACKGROUND: Despite therapy, some patients with rheumatoid arthritis related interstitial lung disease (RA-ILD) require lung transplantation for progressive disease. We aimed to identify factors associated with lung transplantation and post-transplantation survival in RA-ILD. METHODS: We performed a retrospective observational cohort study using data from Ontario, Canada between 2003 and 2022. RA-ILD patients were identified from the Ontario RA Database. We used a cause-specific hazards model, considering the competing risk of death, to identify factors associated with lung transplantation. A Cox proportional hazards model was used to evaluate post-transplant survival. RESULTS: Among 6470 RA-ILD patients, 77 (1.2%) underwent lung transplantation, equating to 2.40 transplants per 1000 person years. The median time to transplant was 3.7 years. Younger age [HR 0.93 per increasing year (95%CI 0.91-0.95), p < 0.0001], male sex [HR 2.40 (95%CI 1.523.78), p = 0.0002], and comorbid diabetes [HR 1.70 (95%CI 1.06-2.73), p = 0.003], congestive heart failure [HR 1.87 (95%CI 1.15-3.04), p = 0.01] and COPD [HR 2.14 (95%CI 1.25-3.68), p = 0.006] were associated with transplantation. The median survival following transplantation was 4.3 years. CONCLUSION: Lung transplantation is an uncommon, but important therapy for RA-ILD. Select comorbidities are associated with lung transplantation. Post-transplant survival among RA-ILD patients in Ontario was comparable to that reported elsewhere.