Influence of gender on response to rituximab in patients with rheumatoid arthritis: results from the Autoimmunity and Rituximab registry

Objective. The response rate to many therapies for RA is lower in women. The aim of this study was to analyse the influence of gender on the response to rituximab (RTX) in patients with RA. Methods. A total of 1709 RA patients were included in the French Autoimmunity and Rituximab (AIR) registry. Disease activity assessed by the 28-joint DAS (DAS28) was recorded at baseline and at follow-up (6, 12, 18 and 24 months). Response criteria [European League Against Rheumatism (EULAR) remission defined as a DAS28 < 2.6 and EULAR response] were compared in both sexes. Results. Seventy-seven per cent of the patients were female (age 61.4 years, disease duration 16 years). Approximately 78.6% of the patients were positive for RF and 75.8% for anti-CCP. Women had a longer disease duration (P < 0.001), less frequently had anti-CCP (P = 0.03) and had lower CRP levels at baseline (P < 0.001). Six months after RTX, 11% were in remission and 62% had a good to moderate EULAR response, irrespective of gender (P = 0.81 and P = 0.38, respectively). No differences were observed in terms of remission or EULAR response during the follow-up except at 12 months, when men achieved remission more frequently (18% vs 12%, P = 0.045). In the cases of anti-TNF failure, remission rates were higher in men than in women at 6, 12 and 18 months. Re-treatment delay between the first and second courses was similar in both genders (P = 0.26). Conclusion. In this large cohort of RA patients we found no significant differences in EULAR response to RTX between men and women during the 2-years of follow-up, but there was a previous anti-TNF exposure-dependent effect of gender on remission rate.