Temporary MTX Discontinuation Ups Flu Vaccine Efficacy in RA
WASHINGTON, DC—Temporarily discontinuing methotrexate (MTX) treatment can improve seasonal influenza vaccination immunogenicity among patients with rheumatoid arthritis (RA), according to a single center, randomized, single-blind, open-label prospective study (NCT02748785) presented at the 2016 ACR/ARHP Annual Meeting.
“Further studies are needed to determine the duration of MTX discontinuation,” cautioned coauthor Eun Bong Lee, MD, of Seoul National University in the Republic of Korea.
RA patients with stable MTX doses were randomly assigned to one of four study groups: continued MTX treatment (Group 1), hold MTX for 4 weeks before vaccination (Group 2) or 2 weeks before and for 2 weeks after vaccination (Group 3), or hold MTX for 4 weeks after vaccination (Group 4).
“We measured HI antibody titers against each antigen at baseline prior to vaccination with trivalent seasonal influenza vaccination containing A/California/72009 (H1N1), A/Switzerland/9715293/2013 (H3N2) and B/Phuket/3073/2013 (B-Yamagata), and then again 4 weeks post-vaccination,” noted Dr. Lee.
A per-protocol population of 219 patients was enrolled (Group 1 n=54; Group 2 n=44; Group 3 n=49; and Group 4 n=52). Titers were similar for all four groups prior to vaccination.
“Four weeks after vaccination, Group 3 and Group 4 showed higher increase in antibody titers against H1N1 and H3N2 and B-Yamagata antigens than Group 1,” Dr. Lee reported. “The percentage of the satisfactory vaccine response against H3N2 and B-Yamagata were statistically higher in Group 3 and Group 4 than Group 1.”
Group 2 and Group 1 had similar increases in antibody titers “and satisfactory vaccine response,” the research team found.
The percentage of patients with H1N1-protective and B-Yamagata-protective titers were “prominently increased” in Group 3 and Group 4 vs. Group 1, Dr. Lee said. “All groups showed high percentage of protective titers for H3N2.”
Influenza vaccine was well tolerated, with RA flares reported in (Groups 1–4): 7.4%, 13.6%, 18.4%, and 11.5% of patients, respectively.