Myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction characterised by an autoantibody against acetylcholine receptor (AChR-Ab), autoantibody against muscle-specific kinase (MuSK-Ab), lipoprotein-related protein 4 or agrin in the postsynaptic membrane at the neuromuscular junction. Many patients are resistant to conventional treatment and effective therapies are needed. Rituximab (RTX) is a monoclonal antibody directed against CD20 antigen on B cells which has been successfully employed in anti-MuSK-Ab+MG, but the efficacy in anti-AChR-Ab+MG is still debated. The purpose of this systematic review was to describe the best evidence for RTX in the acetylcholine receptor subtype. The authors undertook a literature search during the period of 1999-2019 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analys methodology, employing (myasthenia)+(gravis)+(RTX) as search terms. The analysis was confined to studies that include at least five patients with confirmed anti-AChR-Ab+MG. Thirteen studies have been selected, showing a good safety. The data obtained were heterogeneous in terms of posology, administration scheme and patients' evaluation, ranging from a minimum of two to a maximum of three cycles. RTX led to a sustained clinical improvement with prolonged time to relapse, in parallel to a reduction or discontinuation of other immunosuppressive therapies. Treatment with RTX appears to work in some but not all patients with anti-AChR-Ab+MG, but randomised controlled trials are needed. Future studies should take into account the subtype of MG and employ reliable measures of outcome and severity focusing on how to identify patients who may benefit from the treatment. Trial registration number: NCT02110706.

中文翻译：

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利妥昔单抗重症肌无力的AChR亚型：系统评价。

重症肌无力（MG）是一种神经肌肉接头的慢性自身免疫性疾病，其特征在于针对乙酰胆碱受体（AChR-Ab）的自身抗体，针对肌肉特异性激酶（MuSK-Ab）的自身抗体，脂蛋白相关蛋白4或突触后膜中的凝集素在神经肌肉连接处。许多患者对常规治疗有抵抗力，需要有效的治疗方法。利妥昔单抗（RTX）是针对B细胞上CD20抗原的单克隆抗体，已成功用于抗MuSK-Ab + MG，但抗AChR-Ab + MG的功效尚有争议。本系统综述的目的是描述乙酰胆碱受体亚型中RTX的最佳证据。作者根据系统评价的首选报告项目和荟萃分析方法，在1999-2019年进行了文献检索，检索词为（myasthenia）+（gravis）+（RTX）。该分析仅限于包括至少五名确诊抗AChR-Ab + MG的患者的研究。选择了十三项研究，显示出良好的安全性。所获得的数据在病因学，给药方案和患者评估方面均不相同，范围从最少两个到最多三个周期。RTX导致持续的临床改善，延长了复发时间，与此同时减少或终止了其他免疫抑制疗法。RTX治疗似乎对部分但并非全部抗AChR-Ab + MG患者有效，但需要随机对照试验。未来的研究应考虑MG的亚型，并采用可靠的结局和严重程度衡量方法，重点在于如何确定可能从治疗中受益的患者。试用注册号：NCT02110706。