Abstract: Background：There are many widely used immunotherapies for relapse prevention in myelinoligodendrocyte glycoprotein antibodyassociated disease (MOGAD), however, there is no optimal relapse prevention therapy. Objective：To investigate the efficacy of mycophenolate mofetil (MMF) in the treatment of MOGAD. Design：Systematic review and metaanalysis. Methods：English and Chineselanguage articles were searched in PubMed, Embase, Web of Science, Cochrane, Wanfang Data, China National Knowledge Infrastructure (CNKI), and China Science and Technology Journal Database (CQVIP) from the inception to June 1, 2021. All studies related to the efficacy of MMF in treating MOGAD were included regardless of the study design. Inclusion criteria were as the following : the subjects from the original clinical study met the diagnostic criteria of MOGAD, regardless of race, sex, and age; the duration of MMF was ≥ 6 months;the change in annualized relapse rate (ARR) or relapse rate was reported . The literature meeting the following criteria were excluded that studies in which modifying treatment definition was met during treatment; it is unable to obtain the full text; the language is neither English nor Chinese. The metaanalysis was performed using R 4.2.1 and the risk of bias of the included studies was assessed. Main outcome measures：Relapsefree rate and ARR. Results：Twelve studies (161 patients) were included in the metaanalysis, including 1 prospective cohort study and 11 case series reports. Fiftyseven of 161 patients were children, 80 of 161 patients were adults, and age information was unclear in the rest of 24 patients. Age of onset ranged from 1 to 74 years. The followup time ranges from 6 to 67months. Overall, 74% of the patients were relapsefree during followup after MMF therapy (95%CI:58%89%, I2=83%，P＜0.01). ARR was significantly decreased after MMF therapy with a mean reduction of 1.38 times/year (95%CI :0.941.82, I2=0%，P=0.62). Adverse effects was reported in 8%(7/87) of patients, and 5.7%(5/87) of patients discontinued MMF therapy due to serious adverse effects. Conclusion：The metaanalysis showed that the relapsefree rate of MOGAD was 74% after MMF treatment for at least 6 months, and the ARR decreased by 1.38 times/year compared with that pretreatment. More highquality studies were still necessary to confirm the result.

Key words: Anti-myelin oligodendrocyte glycoprotein-IgG associated disorders(MOGAD), Immunotherapy, Mycophenolate mofetil(MMF), Meta-analysis