Effect of methotrexate discontinuation on efficacy of seasonal influenza vaccination in patients with rheumatoid arthritis: A randomised clinical trial

Objective To investigate whether temporary discontinuation of methotrexate (MTX) improves the efficacy of seasonal influenza vaccination in patients with rheumatoid arthritis (RA). Methods In this prospective randomised parallel-group trial, patients with RA taking stable dose of MTX were randomly assigned at a ratio of 1:1:1:1 to continue MTX (group 1), suspend MTX for 4 weeks before vaccination (group 2), suspend MTX for 2 weeks before and 2 weeks after vaccination (group 3) or suspend MTX for 4 weeks after vaccination (group 4). All participants were vaccinated with trivalent influenza vaccine containing H1N1, H3N2 and B-Yamagata. The primary outcome was frequency of satisfactory vaccine response (≥4-fold titre increase 4 weeks postvaccination). Secondary endpoints included fold change in antibody titres from baseline. Results The per-protocol population consisted of 199 patients (n=54, 44, 49 and 52 in groups 1, 2, 3 and 4, respectively). Group 3 achieved higher satisfactory vaccine response against all three antigens than group 1 (51.0% vs 31.5%, p=0.044). The anti-H3N2 antibody fold increase (95% CI) was significantly higher in groups 3 and 4 (12.2 (8.4 to 17.5), p <0.001 and 10.0 (6.8 to 14.8), p=0.043, respectively) than group 1 (5.9 (4.3 to 8.1)). The anti-B-Yamagata antibody responses of groups 3 and 4 were higher (4.7 (3.3 to 6.7), p=0.048; 6.1 (4.2 to 8.8), p <0.001, respectively) than group 1 (2.9 (2.2 to 3.8)). RA flare occurred in 24.1%, 21.2%, 34.1% and 38.8% in groups 1, 2, 3 and 4, respectively (p=NS). Conclusions Temporary MTX discontinuation improves the immunogenicity of seasonal influenza vaccination in patients with RA. Trial registration Trial registration number is: Www.clinicaltrials.gov, NCT02748785.