重症肌无力不同抗体类型的免疫学特征

Immunologic characteristics of different antibody types in myasthenia gravis

目的分析不同抗体分型重症肌无力(MG)患者的临床特点及与其他免疫指标异常的关系。方法选取2017年1月~2018年12月深圳市人民医院和深圳市龙华区中心医院收治的155例MG患者进行研究,使用酶联免疫吸附法测定患者血清中的抗乙酰胆碱受体抗体(AChR Ab)、肌肉特异性激酶抗体(MuSK Ab)。根据AChR Ab、MuSK Ab的表达情况对患者进行分组,分为AChR Ab阳性(+)MG组(103例),MuSK Ab阳性(+)MG组(13例)以及双抗体阴性(DSN)MG组(39例),分析三组的临床表现、实验室检查、胸腺病理类型和治疗方案。结果本研究纳入的MG患者中,AChR Ab(+)MG、MuSK Ab(+)MG、DSN MG构成比分别为:66.4%、8.4%、25.2%。MuSK Ab(+)MG组相较于其余两组更易累及球部肌肉,差异有统计学意义(P<0.05)。三组患者出现肌无力危象的比例比较,差异无统计学意义(P>0.05)。AChR Ab(+)MG组相比于其余两组甲状腺异常率、自身抗体阳性率更高,差异有统计学意义(P<0.05)。AChR Ab(+)MG组、MuSK Ab(+)MG组、DSN MG组三组间的胸腺瘤罹患率分别为55.3%、23.1%及25.6%,组间分析,AChR Ab(+)MG组胸腺瘤罹患率相比于其余两组更高,差异有统计学意义(P<0.05)。结论AChR Ab、MuSK Ab不同表达情况下,MuSK Ab(+)MG起病症状以球部肌肉-眼部肌肉受累较多,但累及肌群较局限。AChR Ab(+)MG易出现甲状腺功能异常和自身抗体异常,且AChR Ab(+)MG更易罹患胸腺瘤。

Objective To explore the clinical characteristics of different antibody types and the relationship with other immune factors in myasthenia gravis.Methods A total of 155 patients with myasthenia gravis(MG)who were admitted to Shenzhen People′s Hospital and Shenzhen Longhua District Central Hospital from January 2017 to December 2018 were enrolled in the study.The anti-acetylcholine receptor antibody(AChR Ab)and antibody to muscle-specific kinase(MuSK Ab)in serum were determined by enzyme-linked immunosorbent assay.Patients were divided into AChR Ab positive(+)MG group,MuSK Ab positive(+)MG group and double seronegative(DSN)MG group according to the expression of AChR Ab antibody and MuSK Ab.The clinical manifestations,laboratory tests,thymic pathology and treatment programs of the three groups were analyzed.Results Among the 155 MG patients included in this study,the composition ratios of AChR Ab(+)MG,MuSK Ab(+)MG,and DSN MG were 66.4%,8.4%,and 25.2%respectively.After comparison,MuSK Ab(+)MG group was more likely to involve the muscles of the ball than the remaining two groups,the difference was statistically significant(P<0.05).There was no significant difference in the proportion of myasthenic crisis among the all groups(P>0.05).The AChR Ab(+)MG group had a higher thyroid abnormality rate and autoantibody positive rate than the remaining two groups,and the difference was statistically significant(P<0.05).The incidence of thymoma among the AChR Ab(+)MG group,MuSK Ab(+)MG group,and DSN MG group was 55.3%,23.1%,and 25.6%,respectively.Comparing each subgroup,the AChR Ab(+)MG group had a higher the incidence of thymoma than the remaining two groups,the difference was statistically significant(P<0.05).Conclusion With the different expressions of AChR Ab and MuSK Ab,MuSK Ab(+)MG was more likely to present bulbar muscles or extraocular muscles and the muscles are more limited.AChR Ab(+)MG is prone to abnormal thyroid function and has a higer autoantibody positive rate.AChR Ab(+)MG are prone to be associated with thymoma.