Abstract：
Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction of the neuromuscular junction resulting in skeletal muscle weakness. It is equally prevalent in males and females, but debuts at a younger age in females and at an older age in males. Ptosis, diplopia, facial bulbar weakness, and limb weakness are the most common symptoms. MG can be classified based on the presence of serum autoantibodies. Acetylcholine receptor (AChR) antibodies are found in 80%-85% of patients, muscle-specific kinase (MuSK) antibodies in 5%-8%, and <1% may have low-density lipoprotein receptor-related protein 4 (Lrp4) antibodies. Approximately 10% of patients are seronegative for antibodies binding the known disease-related antigens. In patients with AChR MG, 10%-20% have a thymoma, which is usually detected at the onset of the disease. Important differences between clinical presentation, treatment responsiveness, and disease mechanisms have been observed between these different serologic MG classes. Besides the typical clinical features and serologic testing, the diagnosis can be established with additional tests, including repetitive nerve stimulation, single fiber EMG, and the ice pack test. Treatment options for MG consist of symptomatic treatment (such as pyridostigmine), immunosuppressive treatment, or thymectomy. Despite the treatment with symptomatic drugs, steroid-sparing immunosuppressants, intravenous immunoglobulins, plasmapheresis, and thymectomy, a large proportion of patients remain chronically dependent on corticosteroids (CS). In the past decade, the number of treatment options for MG has considerably increased. Advances in the understanding of the pathophysiology have led to new treatment options targeting B or T cells, the complement cascade, the neonatal Fc receptor or cytokines. In the future, these new treatments are likely to reduce the chronic use of CS, diminish side effects, and decrease the number of patients with refractory disease.
摘要：
重症肌无力（MG）是一种自身免疫性疾病，其特征是神经肌肉接头功能障碍，导致骨骼肌无力。它在男性和女性中同样普遍，但在女性中年龄较小，在男性中年龄较大。眼睑下垂,复视,面部延髓无力，和四肢无力是最常见的症状。MG可以基于血清自身抗体的存在进行分类。乙酰胆碱受体（AChR）抗体在80％-85％的患者中发现，肌肉特异性激酶（MuSK）抗体在5％-8％，和<1％可能有低密度脂蛋白受体相关蛋白4（Lrp4）抗体。大约10%的患者对于结合已知疾病相关抗原的抗体是血清阴性的。在AChRMG患者中，10%-20%有胸腺瘤,通常在疾病发作时检测到。临床表现之间的重要差异，治疗反应性，在这些不同的血清MG类别之间观察到了疾病机制。除了典型的临床特征和血清学检测，诊断可以通过额外的测试来确定，包括重复的神经刺激,单纤维肌电图，和冰袋测试。MG的治疗选择包括对症治疗（如吡啶斯的明），免疫抑制治疗,或者胸腺切除术.尽管用对症药物治疗，保留类固醇的免疫抑制剂，静脉注射免疫球蛋白，血浆置换,和胸腺切除术,很大一部分患者仍然长期依赖皮质类固醇(CS).在过去的十年里,MG的治疗选择数量大大增加。对病理生理学的理解的进步导致了针对B或T细胞的新治疗选择。互补级联，新生儿Fc受体或细胞因子。在未来,这些新疗法可能会减少CS的长期使用，减少副作用，减少难治性疾病患者的数量。
