[Efficacy and safety of rituximab in the treatment of pediatric myasthenia gravis].

Objective: To evaluate the efficacy and safety of rituximab in pediatric myasthenia gravis (MG). Methods: Case series study. The clinical manifestations, laboratory tests, treatment plans and prognosis of 27 pediatric MG patients treated with rituximab from June 2013 to June 2023 at Children's Medical Center of Peking University First Hospital were retrospectively collected. Results: There were 5 males and 22 females in 27 MG children. The onset age was 2.1 (1.6, 4.8) years, ranging from 8 months to 11 years. The clinical classification included 20 children (74%) of ocular MG and 7 children (26%) of generalized MG. Seventeen children (63%) had positive MG-related pathogenic antibodies, including 17 children of anti-AchR antibody and 1 of them also had anti-MuSK antibody. Rituximab was used as first-line immunosuppressant in 13 children, second-line immunosuppressant in 13 children and third-line immunosuppressant in 1 child. Immunosuppressants used before rituximab including 8 children of cyclosporine, 3 children of tacrolimus, 1 child of azathioprine, 1 child of mycophenolate mofetil and 1 child of cyclosporine combined with azathioprine. Rituximab was used for at least half a year with a follow-up period of more than 12 months. At the last follow-up after rituximab treatment, all children achieved improved or above, 14 children (52%) achieved complete stable remission, 7 children (26%) achieved pharmacologic remission, 1 child (4%) achieved minimal manifestations, and 5 children (18%) improved. After rituximab treatment, 27 children all could reduce the immunomodulation therapy and shorten the course of glucocorticoid therapy, and 22 children (81%) had stopped the glucocorticoid therapy. Among the 14 children with poor efficacy of other immunosuppressants, rituximab had complete stable remission of 7 children. The most common adverse reaction was respiratory infection (4 children (15%)). Only 2 children had allergic reaction to rituximab and got better after symptomatic treatment. Conclusions: Rituximab has good efficacy and tolerance in pediatric MG. Early application of rituximab can improve the prognosis and shorten the course of glucocorticoid treatment.