重症肌无力的发病机制  

The pathogenesis of myasthenia gravis

作　　者：黄一铿 黄嘉正 曾辰林 伏熹 许从峰 HUANG Yikeng;HUANG Jiazheng;ZENG Chenlin;FU Xi;XU Congfeng(Shanghai Jiao Tong University School of Medicine,Shanghai 200025,China;Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University,Shanghai 200233,China)

机构地区：[1]上海交通大学医学院,上海200025 [2]上海交通大学附属第六人民医院,上海200233

出　　处：《生命的化学》2021年第11期2327-2333,共7页Chemistry of Life

基　　金：国家自然科学基金项目(31870885);上海市卫生健康委员会项目(201840173)。

摘　　要：重症肌无力(myasthenia gravis,MG)是一种病变发生在骨骼肌神经肌接头(neuromuscular junction,NMJ)处的自身免疫病。其临床症状主要为骨骼肌波动性的无力和病态的易疲劳,这对患者的日常生活造成极大影响。MG的发病与骨骼肌神经肌接头相关结构的病变有关,后者由接头前膜、接头后膜以及接头间隙构成。正常情况下,骨骼肌神经肌接头通过神经递质乙酰胆碱介导完成兴奋的传递;而当机体免疫系统功能出现异常,影响到神经肌接头的正常结构和功能时,则会导致MG的发生。自身抗体的产生是引发MG的主要机制,其中大于80%的病例是由针对接头后膜上的烟碱型乙酰胆碱受体(nicotinic acetylcholine receptor,nAChR)的抗体所引起,而在n ACh R抗体阴性的部分病例中,则可见针对骨骼肌特异性酪氨酸激酶(muscle-specific tyrosinekinase,MuSK)、及低密度脂蛋白受体相关蛋白4(low density lipoprotein receptor-relatedprotein 4,LRP4)等的自身抗体。除体液免疫外,胸腺的损伤、补体途径的作用以及某些细胞因子和其他分子的作用也参与到MG的发病机制中。本文旨在总结MG的临床特点,概括MG的发病机制,为该疾病的进一步研究提供新的思路。Myasthenia gravis(MG)is a kind of autoimmunity disease in which lesions occur at the neuromuscular junction of skeletal muscles.Mainly manifested as skeletal muscular weakness and pathological fatigue,the disease has a great impact on the daily life of patients.The pathogenesis of MG is related to the lesion of the structures associated with the neuromuscular junction,which is composed of prejunctional membrane,postjunctional membrane and junctional cleft.Under normal circumstances,the neuromuscular junction is mediated by acetylcholine,the neurotransmitter to complete the transmission of excitation.However,the dysfunction of the immune system can cause the structural and functional disorders of the neuromuscular junction,leading to MG.Currently,accumulating evidence indicates that the production of autoantibodies is the main mechanism of inducing MG,and more than 80% of cases are caused by antibodies to nicotinic acetylcholine receptor(nAChR)located on the postjunctional membrane.In patients without nAChR antibodies,autoantibodies against MuSK and LRP4 can be examined.Beyond that,thymus injury,complement pathway,and some cytokines and other molecules are also involved in the pathogenesis of MG.The aim of this short review is to summarize the clinical characteristics of MG,as well as the pathogenesis of MG,thus providing a new idea for the further study of this disease.

关 键 词：重症肌无力 发病机制 nAChR抗体 临床表现 神经肌接头 

分 类 号：R746.1[医药卫生—神经病学与精神病学]