Background: Abatacept (ABT) is clinically used as the only T-cell modifier available for rheumatoid arthritis treatment and has shown similar efficacy as tumour necrosis factor inhibitors and a safer profile, especially a lower infection ratio in registry data. Latourte et al. recently published the results of perioperative complications of orthopaedic and other types of surgery in patients using ABT. However, they did not compare the complication rates with those in patients who received csDMARDs. It remains unknown whether ABT is associated with more postoperative complications than conventional synthetic DMARDs (csDMARDs).

Objectives: The aims of this study were to investigate whether ABT is associated with more adverse events after orthopaedic surgery compared with csDMARDs and, if so, to identify significant risk factors for those events.

Methods: A retrospective multicenter nested case–control study was performed in 18 institutions. Patients receiving ABT were matched individually with patients receiving csDMARDs and/or steroid. Serious adverse events were defined as surgical site infection, delayed wound healing, deep vein thrombosis or pulmonary embolism, flare-up, serious infection in other organs. The incidence rates of serious adverse events in both groups were compared with Mantel-Haenzel test. Risk factors for serious adverse events in the ABT group were analyzed by logistic regression model.

Results: A total of 3358 cases were collected. After inclusion and exclusion, 2651 patients were selected for matching, and 194 patients in 97 pairs were chosen for subsequent comparative analyses between the ABT and control groups. No between-group differences were detected in the incidence rates of each adverse event or in the combined incidence rate of adverse events. The odds ratio of the history of serious infection for serious adverse events was 12.6 (95%CI 1.12–141, P=0.04) in patients who received ABT and underwent orthopaedic surgery.

Conclusions: Compared with csDMARDs and/or steroid without ABT, adding ABT to the treatment does not appear to increase the incidence rates of postoperative adverse events in rheumatoid arthritis patients undergoing orthopaedic surgery. A history of serious infection is a significant risk factor for both infection and other serious adverse events, and such patients should be treated with particular caution.

Reference [1]Latourte A, et al. Safety of surgery in patients with rheumatoid arthritis treated by abatacept: data from the French Orencia in Rheumatoid Arthritis Registry. Rheumatology (Oxford)2017Apr 1;56(4):629–637.

Disclosure of Interest: H. Ito Grant/research support from: BMS, ONO Pharmaceutical, S. Tsuji: None declared, M. Nakayama: None declared, Y. Mochida: None declared, K. Nishida: None declared, H. Ishikawa: None declared, T. Kojima: None declared, T. Matsumoto: None declared, A. Kubota: None declared, T. Mochizuki: None declared, K. Sakuraba: None declared, I. Matsushita: None declared, A. Nakajima: None declared, R. Hara: None declared, A. Haraguchi: None declared, T. Matsubara: None declared, K. Kanbe: None declared, N. Nakagawa: None declared, M. Haraguchi: None declared, S. Momohara: None declared