重症肌无力抗突触受体抗体的检测及其意义

The measurement of anti-synapse receptor antibodies and its significance in myasthenia gravis

目的：探讨一种阳性率更高的实验指标，以提高重症肌无力的实验室诊断率。方法：将α一银环蛇毒素和β－银环蛇毒素混合一起包被酶标板，结合随后加的肌肉提取液中相应蛋白质为抗原，以ＡＢＣ－ＥＬＩＳＡ法检测重症肌无力病人血清中混合的抗乙酰胆碱受体抗体（ＡｃｈＲａｂ）和抗突触前膜受体抗体（ＰｓｍＲａｂ），称为抗突触受体抗体。结果：７５名正常人均阴性。８０例临床对照组中，除２例运动神经元疾病和１例多发性肌炎阳性外，其余均阴性。本组１２２例重症肌无力病人中９８例阳性（８０．３％，其中全身型阳性８７．５％），阳性率明显高于单独检测ＡｃｈＲａｂ，（Ｐ＜０．００１）。结论：检测抗突触受体抗体可作为重症肌无力诊断的一个阳性率较高的较好的实验室指标。

It is important to measure antiacetylcholine receptor antibody (AchRab) and antipresynaptic membrane receptor antibody(PsmRab) in the patient with myasthenia gravis (MG).However,both of them are of low positive rate. The aim of the study was to explore a new method to enhance the diagnostic rate in MG. The wells in the microtiter plates were coated with αand βbungarotoxin to purify the antigen in human muscle extract. Both AchRab and PsmRab in the sera of the MG patients called anti-synapse receptor antibodies (SRab) were measured by ABCELISA.The neutraligation test showed that this method was specific. All of seventyfive healthy controls were of negative SRab .Except one case with polymyositis and two cases with motor neuron disease,all other 77 clinical controls were of negative SRab. In the MG group, the positive rate of SRab measurement was 80.3% (98/122) ,which was much higher than that of either only AchRab (63.1% ,P<0.001) or PsmRab (64.8%,P<0.001) measruement.The authors concluded that the measurement of the SRab may be a higher positive rate laboratory parameter for MG diagnosis.