重症肌无力患者胸腺切除术后合并视神经脊髓炎1例（附文献复习）

目的：分析重症肌无力（MG）患者胸腺切除后合并视神经脊髓炎的临床特点,探讨两者合并发生的机制。方法：结合文献对1例MG胸腺切除后合并视神经脊髓炎患者的临床特点和血清学改变进行分析。结果：现有的MG合并视神经脊髓炎的文献报道中,绝大多数（13/15例）在胸腺切除后发生。胸腺切除后抑制T细胞产生减少,B细胞过度增殖,自身免疫抗体增加,可能与视神经脊髓炎的发病有关。此外,HLAB8、DR2和DR3也可能与MG合并视神经脊髓炎的发生相关。结论：MG患者胸腺切除后引起的免疫系统改变（如血清中抑制T细胞数的改变和自身抗体的出现）,患者的HLA抗原类型（如HLA-B8、DR2和DR3）可能与合并视神经脊髓炎的发生相关。

Neuromyelitis Optica in Patients with Myasthenia Gravis Who Underwent Thymectomy:A Case Report (Literature Review)

Aim：To analyze clinical characteristcs of the occurrence of neuromyelitis optica（NMO） in patients with myasthenia gravis（MG） after thymectomy and to explore possible causes of apparent increased prevalence of NMO among patients with MG.Methods：Clinical characteristic as well as NMO-IgG and autoantibodies in the serum of this case were described and related literatures were reviewed.Results：Most of the published cases（13/15） which reported coocurrence of MG and NMO were among MG patients who underwent thymectomy.Exacerbated B-cells activity due to the failure to generate suppressor T-cells after thymectomy might contribute to the cooccurrence of MG and NMO.Besides,the presence of B8,DR2 and DR3 HLA antigens seem to increase the risk of concurrent autoimmune conditions.Conclusion：Changes in immune system（such as the decrease of suppressor T-cells and increase of autoantibodies） triggered by thymectomy and the HLA typing（B8,DR2 and DR3） possibly correlated with coexistence of MG and NMO.