Expert commentary
This current study is consistent with other studies over the last several months showing that methotrexate harms both humoral and cell-mediated COVID-19 responses, noted Kevin Winthrop, MD, MPH, professor of infectious disease and public health at Oregon Health & Science University, Portland, who was not involved in the study. “And so now the new wave of studies are like this one, where they are holding methotrexate experimentally and seeing if it makes a difference,” he said.
Dr. Kevin Winthrop
“The one shortcoming of this study – and so far, the studies to date – is that no one has looked at whether the experimental hold has resulted in a change in T-cell responses, which ... we are [now] recognizing [the importance of] more and more in long-term protection, particularly in severe disease. Theoretically, holding [methotrexate] might help enhance T-cell responses, but that hasn’t been shown experimentally.”
Dr. Winthrop pointed out that one might get the same benefit from holding methotrexate for 1 week instead of 2 and that there likely is a reduced risk of flare-up from underlying autoimmune disease.
It is still not certain that this benefit extends to other vaccines, Dr. Winthrop noted. “It is probably true for most vaccines that if you hold methotrexate for 1 or 2 weeks, you might see some short-term benefit in responsiveness, but you don’t know that there is any clinical meaningfulness of this. That’s going to take other long-term studies. You don’t know how long this benefit lasts.”
Pausing methotrexate during initial COVID vaccine doses
Patients with either rheumatoid arthritis or psoriatic arthritis had higher anti-RBD antibody titers when methotrexate was stopped after both doses of the AstraZeneca vaccine, or simply after the second dose, than when methotrexate was continued, according to results from two single-center, randomized controlled trials called MIVAC I and II, Anu Sreekanth, MD, of Sree Sudheendra Medical Mission in Kochi, Kerala, India, and colleagues reported at EULAR 2022.
Dr. Anu Sreekanth
Results from MIVAC I indicated that there was a higher flare rate when methotrexate was stopped after both vaccine doses, but there was no difference in flare rate in MIVAC II when methotrexate was stopped only after the second dose as opposed to stopping it after both doses.
In the MIVAC I trial, 158 unvaccinated patients were randomized 1:1 to a cohort in which methotrexate was held for 2 weeks after both doses and a cohort in which methotrexate was continued despite the vaccine. In MIVAC II, 157 patients continued methotrexate while receiving the first vaccine dose. These patients were subsequently randomized either to continue or to stop methotrexate for 2 weeks following the second dose.
The findings from MIVAC I demonstrated the flare rate was lower in the methotrexate-continue group than in the methotrexate-pause group (8% vs. 25%; P = .005) and that the median anti-RBD titer was significantly higher for the methotrexate-pause group than the methotrexate-continue group (2,484 vs. 1,147; P = .001).
The results from MIVAC II trial indicated that there was no difference in flare rates between the two study groups (7.9% vs. 11.8%; P = .15). Yet, the median anti-RBD titer was significantly higher in the methotrexate-pause cohort than in the methotrexate-continue cohort (2,553 vs. 990; P = .001).
The report suggests there is a flare risk when methotrexate is stopped, Dr. Sreekanth noted. “It appears more logical to hold only after the second dose, as comparable anti-RBD titers are generated” with either approach, Dr. Sreekanth said.