Methotrexate hiatus improved influenza vaccine efficacy in patients with RA

SAN DIEGO — Discontinuing methotrexate for 2 weeks following vaccination improved the effectiveness of the seasonal influenza vaccine among patients with rheumatoid arthritis without exacerbating disease activity, according to findings presented at the American College of Rheumatology Annual Meeting.

In a pilot trial published earlier this year, Jin Kyun Park, MD, assistant professor of medicine at Seoul National University Hospital in South Korea and colleagues determined that suspending methotrexate for 2 to 4 weeks before or after vaccination altered vaccine-immune response among patients with RA.

“The vaccine response was quite interesting. When methotrexate was withheld 2 weeks before vaccination, there was no difference compared to patients who continued using methotrexate,” Park said during a press conference. “However, if we withhold methotrexate 4 weeks after vaccination, we saw an improved vaccine response of 15% to 20%, but an increase in [arthritis] flare rate of 38.8%. Based on this result, we thought that 2 weeks after vaccination might be enough to improve the vaccine response without increasing the risk of flare.”

To determine whether this reduced cessation period would improve vaccine efficacy while mitigating flare risk, Park and colleagues conducted a prospective, multicenter, randomized trial, that enrolled patients with RA (n=320) into two groups: patients who continued with their standard methotrexate dose (n=156); and patients who suspended methotrexate for 2 weeks following influenza vaccination. All patients received vaccinations with a seasonal, quadrivalent influenza vaccine that contained H1N1, H3N2, B-Yamagata and B-Victoria.

According to study results, 75.5% of patients in the methotrexate cessation group achieved satisfactory vaccine response vs. 54.5% of patients who did not discontinue methotrexate. Researchers also found no difference in disease activity following vaccination between the groups.

Following vaccination, researchers observed the seroprotection rate was higher for all four antigens measured in the group that discontinued methotrexate for 2 weeks than the group that continued (H1N1: 75.6% vs. 86.3%; H3N2: 62.2% vs. 78.1%; B-Yamagata: 74.4% vs. 88.1%; B-Victoria: 60.9% vs. 75.6%)

In addition, patients with RA who discontinued methotrexate following vaccination also attained a higher-fold increase of H1 antibody titer in geometric mean titer for each antigen (H1N1: 4.6 vs. 6.7; H3N2: 4.3 vs. 8.; B-Yamagata: 3.1 vs. 5.6; B-Victoria: 2.9 vs. 5.7).

However, Park noted in a press release, “Since antibody production does not always guarantee immune protection, further studies are needed to address as to whether the increased immunogenicity by holding methotrexate for 2 weeks can prevent flu infection.”– by Bob Stott

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Reference:

Park JK, et al. Abstract 827. Presented at: American College of Rheumatology Annual Meeting; Nov. 4-8, 2017; San Diego.

Disclosures: Park reports no relevant financial disclosures. Please see the full study for a complete list of all other authors’ relevant financial disclosures.