ABATACEPT IN MONOTHERAPY VERSUS COMBINED IN INTERSTITIAL LUNG DISEASE OF RHEUMATOID ARTHRITIS. MULTICENTER STUDY OF 263 CAUCASIAN PATIENTS.

Objective To assess the efficacy and safety of abatacept (ABA) in monotherapy (ABAMONO) versus combined-ABA, ABA plus methotrexate (ABAMTX) or ABA plus non-MTX conventional-DMARDs (ABANON-MTX), in Rheumatoid Arthritis (RA) patients with Interstitial Lung Disease (ILD) (RA-ILD). Methods Restrospective multicenter study of RA-ILD Caucasian patients treated with ABA. We analyzed in the three groups (ABAMONO, ABAMTX, ABANON-MTX) the following outcome variables: a) Dyspnea b) FVC and DLCO c) chest HRCT, d) DAS28-ESR, e) corticosteroid-sparing effect, f) ABA retention and side-effects. Differences between basal and final follow-up were evaluated. Multivariable linear regression was used to assess the differences between the three groups. Results We studied 263 RA-ILD patients (mean age 64.6±10 years) [ABAMONO (n = 111), ABAMTX (n = 46) and ABANON-MTX (n = 106)]. At baseline, ABAMONO patients were older (67±10 years) and took higher prednisone dose (10 [IQR 5-15] mg/day). At that time, there were no statistically significant differences in sex, seropositivity, ILD patterns, FVC and DLCO or disease duration. Following treatment, in all groups, most patients experienced stabilization or improvement in FVC, DLCO, dyspnoea, chest-HRCT as well as improvement in DAS28-ESR. A statistically significant difference between basal and final follow-up was only found in corticosteroid-sparing effect in the group on combined-ABA (ABAMTX or ABANON-MTX). However, in the multivariable analysis, there were no differences in any outcome variables between the three groups. Conclusion In Caucasian individuals with RA-ILD, ABA in monotherapy or combined with MTX or with other conventional-DMARDS seems to be equally effective and safe. However, a corticosteroid-sparing effect is only observed with combined-ABA.