我国华南地区MuSK抗体阳性重症肌无力患者的临床特点

Clinical characteristics of MuSK antibody positive myasthenia gravis patients in Southern China

目的分析我国华南地区骨骼肌特异性酪氨酸激酶抗体(MuSK-Ab)阳性重症肌无力(myasthenia gravis,MG)的临床特点。方法回顾性收集2017年8月至2019年8月在中山大学附属第一医院确诊的住院MuSK抗体阳性MG(MuSK-MG)患者26例,并选取同期收治的乙酰胆碱受体抗体(AChR-Ab)阳性MG(AChR-MG)患者157例作为对照组,比较两组患者临床特点以及对治疗反应的差异。结果与AChR-MG患者比较,MuSK-MG患者女性构成(80.8%比58.0%,P<0.05)、平均发病年龄〔(43.12±13.02)岁比(36.04±17.97)岁,P<0.05〕高,球部肌受累(96.2%比70.1%,P<0.01)和肌无力危象(myasthenic crisis,MC;61.4%比28.7%,P<0.05)更常见。两组患者新斯的明试验阳性率(61.5%比70.7%)、低频重复神经电刺激(RNS)阳性率(78.3%比83.3%)比较差异无统计学意义(均P>0.05)。在治疗反应方面,胆碱酯酶抑制剂(AChEIs)对MuSK-MG患者的有效率低于AChR-MG患者(16.0%比58.6%,P<0.01)。两组患者发生MC期间,对血浆置换(PLEX)的反应优于静脉注射丙种球蛋白(IVIG)。结论我国华南地区MuSK-MG以40岁左右女性多见,与AChR-MG比较易累及球部肌和呼吸肌,容易发生MC。MuSK-MG对AChEIs的反应性低于AChR-MG。RNS对我国华南地区MuSK-MG诊断的敏感性与AChR-MG比较无统计学差异,但高于欧美人群。PLEX在MuSK-MG患者的危象前或危象状态中的应用可显著缓解病情。

Objective To analyze the clinical characteristics of skeletal muscle specific tyrosine kinase antibody(MuSK-Ab)positive myasthenia gravis(MG)in Southern China.Methods From August 2017 to August 2019,26 MG inpatients with MuSK-Ab(MuSK-MG group)diagnosed in the first affiliated hospital of Sun Yat-Sen University were reviewed and 157 MG inpatients with acetylcholine receptor antibody(AChR-Ab)were selected as a control group(AChR-MG group).The clinical characteristics and treatment response of the two groups were compared.Results Compared with the AChR-MG patients,the female composition(80.8%vs.58.0%,P<0.05)and average onset age [(43.12±13.02)years vs.(36.04±17.97)years,P<0.05]of the MuSK-MG patients were higher.Bulbar muscle involvement(96.2% vs.70.1%,P <0.01)and myasthenic crisis(MC)(61.4% vs.28.7%,P<0.05)of the MuSK-MG group were more common than the AChR-MG group.There was no significant difference in the positive rate of neostigmine test(61.5%vs.70.7%,P>0.05)or low frequency repetitive nerve stimulation(RNS)(78.3%vs.83.3%,P>0.05)between the two groups.In terms of therapeutic response,the effective rate of cholinesterase inhibitors(AChEIs)in the MuSKMG patients was lower than that in the AChR-MG patients(16.0%vs.58.6%,P<0.01).During the period of MC,the response to PLEX in the two groups was superior to intravenous immunoglobulin(IVIG).Conclusions In Southern China,MuSK-MG patients are more common in 40 years old women.They are more likely to present bulbar muscles and respiratory muscle weakness than AChR-MG patients.And MC is more likely to occur in MuSK-MG patients.The sensitivity of RNS to MuSK-MG in Southern China is similar to AChR-MG and higher than that in Europe and the United States.The efficacy of AChEIs in MuSK-MG patients is lower than AChR-MG.The application of PLEX in MuSK-MG patients in the state of crisis or pre-crisis can significantly relieve the condition.