Abstract
Background: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a major complication of rheumatoid arthritis (RA), but effective treatment remains an unmet need in its management. Our aim was to evaluate the therapeutic efficacy of abatacept for RA-ILD. Methods: This observational retrospective study included patients with RA-ILD treated with abatacept between 2012 and 2021. Indices of RA disease activity and interstitial lung disease (Disease Activity Score in 28 joints using C-reactive Protein [DAS28-CRP], Simplified Disease Activity Index [SDAI], Clinical Disease Activity Index [CDAI], serum Krebs von den Lungen-6 levels, % forced vital capacity [%FVC], and semi-quantified chest high-resolution computed tomography scores) were evaluated before and 1 year after the start of abatacept administration. Results: Overall, 38 patients were included. DAS28-CRP, SDAI, and CDAI were significantly improved (all with p < 0.0001). Total ground-glass opacity scores were decreased in both patients with usual interstitial pneumonia (UIP)-like patterns and with non-UIP-like patterns (p = 0.008 and <0.002, respectively). Total fibrosis scores were also decreased in the UIP-like pattern group (p < 0.042). The %FVC remained stable. Conclusions: Abatacept significantly improves RA disease activity and reduces pulmonary inflammation in patients with RA-ILD.