The effects of methotrexate on the immune responses to the COVID-19 vaccines in the patients with immune-mediated inflammatory disease: A systematic review of clinical evidence

COVID-19 vaccines exhibit high levels of immunogenicity in the overall population. Data on the effects of immunomodulators on the consequences of COVID-19 in patients with Immune-mediated inflammatory diseases (IMIDs) remains scarce. This systematic review aimed to evaluate the immune responses to the COVID-19 vaccines in IMID patients receiving methotrexate (MTX) compared to healthy individuals. A comprehensive literature search was carried out using electronic databases such as PubMed, Web of Science, Scopus, Google Scholar, and Embase up to August 2022 to identify eligible RCTs evaluating the effect of MTX on immune responses in patients with COVID-19. The PRISMA checklist protocol was applied for the quality assessment of the selected trials. Our findings demonstrated that MTX lowered the responses of T cells and antibodies in IMID patients compared to healthy controls. We also discovered that young age (<60 years) was the main parameter influencing the antibody response after vaccination, while MTX had little effect. Following vaccination, MTX-hold and age were considered the main factors influencing the antibody response. In patients older than 60 years of age, the time point of 10 days of MTX discontinuation was critical to boosting the humoral response to anti-SARS-CoV-2 IgG. Because many IMID patients did not have adequate humoral and cellular responses, our findings highlighted the importance of second or booster doses of vaccine and temporary MTX discontinuation. As a result, it implies that individuals with IMIDs should be subjected to more research, particularly humoral and cellular immunity efficiency trials after COVID-19 vaccination, until credible information is achieved.