Efficacy of rituximab in neuromyelitis optica: A meta-analysis

Background: Neuromyelitis optica (NMO) is a severe autoimmune disorder of inflammatory central nervous system, which often resulting in paralysis or blindness. Rituximab (RTX) is a mouse-human chimeric monoclonal antibody specific for the CD20 antigen on B lymphocytes used to treat many autoimmune diseases. This review performed a meta-analysis of the efficacy of rituximab use in NMO. Methods: We searched through the databases of PubMed, Embase, and Cochrane Library. We compiled 28 studies in this meta-analysis: 19 used annualized relapse rate (ARR) ratio, 24 used Expanded Disability Status Scale (EDSS) score. Differences in the ARR ratio and EDSS score before and after rituximab therapy were the main efficacy measures. After a consistency test, the publication bias was evaluated and a sensitivity analysis was performed with mean difference (MD) of the efficacy of rituximab. Results: A meta-analysis of 28 studies with 613 participants total was conducted. NMO patients have antibodies against aquaporin 4 autoantibody (AQP4-Ab) were recorded in 440 of 613 (71.78%). The mean difference of ARR ratio after rituximab therapy was 1.59 (95% CI, 1.33 to 1.85), and a mean difference 1.14 (95%CI, 0.95 to 1.33) reduction in the mean EDSS score. 345 of 563 patients (61.28%) reached a relapse-free state. 94 of 613 (15.33%) patients had adverse reactions. Conclusions: RTX has acceptable tolerance, reduces the frequency of relapse, and improves disability in most patients. However, the potential impact of early diagnosis of NMO and treatment with RTX in reducing health-care costs and improving functional outcome should be carefully addressed in future studies.