Background Previous studies suggested that obesity could play a role in the outcome of rheumatoid arthritis (RA) and negatively affect the response to anti-TNFα agents. However, data are lacking on how it affects the response to abatacept (ABA).

Objectives We aimed to determine whether body mass index (BMI) is involved in the response to ABA in RA.

Methods In this multicenter retrospective study, we included 141 RA patients treated with ABA. BMI was calculated at the initiation of treatment. After six months of treatment, change from baseline in DAS28, pain on a visual analog scale, erythrocyte sedimentation rate and C-reactive protein level, tender and swollen joints, and consumption of corticosteroids were analyzed. The primary endpoint was decrease in DAS28 ≥1.2. Secondary outcomes were good EULAR response and EULAR remission.

Results At baseline, the median [interquartile range] BMI was 26.0 [22.9-30.8] kg/m². The number of patients with normal weight, overweight and obesity was 64, 38 and 39, respectively. Baseline characteristics (erosive status, sex, age, disease duration, and status FR anti-CCP) did not differ between the three subgroups of BMI. After six months, the number of RA patients with DAS28 decrease ≥1.2 and EULAR good response and remission was 57 (40.4%), 26 (18.4%) and 19 (13.5%), respectively.

In univariate analysis, there was no difference in BMI between responders and non-responders for DAS28 decrease ≥1.2 (25.0 [23.4-31.3] vs. 26.3 [22.9-30.2], P=0.95), EULAR good response (26.4 [23.5-30.9] vs. 26.0 [22.9-30.6], P=0.96) and remission (26.7 [21.7-30.3] vs. 26.0 [23.0-30.1], P=0.83).

Conclusions Contrary to anti-TNFα, BMI did not influence the response to ABA in RA. Prospective studies are needed to confirm these data. If confirmed, these results could be useful for the selection of biologic agent in obese RA patients.

Disclosure of Interest None declared