Updated systematic literature review and meta-analysis to inform the Italian Society of Rheumatology Recommendations on the treatment of rheumatoid arthritis-associated interstitial lung disease

Background: rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a severe extra-articular manifestation of rheumatoid arthritis (RA). Despite recent guideline initiatives, no treatment recommendations specifically tailored to RA-ILD have been developed in Italy. This systematic literature review (SLR) and meta-analysis was conducted to inform the Italian Society of Rheumatology (SIR) national recommendations for the management of RA-ILD. Methods: we conducted a systematic review and meta-analysis of studies evaluating pharmacological interventions for RA-ILD from inception up to October 2023, followed by an update up to April 2025, with a pre-defined protocol. Eligible studies included randomized controlled trials, cohort studies, and case series reporting pulmonary function outcomes, radiological progression, adverse events, and mortality. Meta-analyses were performed, and heterogeneity and publication bias were thoroughly assessed. Results: sixty-nine studies encompassing 7879 RA-ILD patients were included. Treatments with conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs), rituximab (RTX), mycophenolate mofetil (MMF), abatacept (ABA), and Janus kinase inhibitors (JAKi) were associated with stabilization or improvement of forced vital capacity (FVC). Methotrexate (MTX) was associated with reduced risk of ILD progression and mortality. Antifibrotics, particularly nintedanib, demonstrated variable efficacy, while pirfenidone showed limited benefit. Safety profiles favored antifibrotics over csDMARDs/immunosuppressants regarding serious adverse events. Conclusions: this SLR provides an updated synthesis of evidence on RA-ILD treatments, supporting the forthcoming SIR recommendations. Despite inherent limitations of observational studies and heterogeneity, the data highlight the safety of MTX and particularly support ABA, RTX, and nintedanib as promising options, while underscoring the need for further high-quality trials specifically in RA-ILD.