Pathogenic Th17 cells are a potential therapeutic target for tacrolimus in AChR-myasthenia gravis patients.

In our study, we investigated the impact of tacrolimus (TAC) on CD4+ T cell subsets in 41 AChR-MG patients over 12 weeks. Twenty-seven patients were classified as the response group (RG) (improved myasthenia gravis composite scores ≥3), while 14 were non-response. We found that TAC treatment significantly reduced Th17 and pathogenic Th17 cells, along with IL-17 levels in RG, while Th1 and Tfh cells slightly decreased without affecting Th2 or Treg subsets. This indicates that TAC's clinical benefits may be due to its inhibitory effect on the Th17 response, enhancing our insight into its immunomodulatory mechanisms in MG management.