重症肌无力患者抗骨骼肌抗心肌抗体与心脏损害

The Relationship between Skeletal and Heart Reactive Autoantibodies and Heart Involvement in Patients with MG

目的探讨重症肌无力（ＭＧ）合并心脏损害的发病机制。方法采用无创性心脏检查对５６例ＭＧ患者进行心电图、彩色多普勒二维超声心动图和心肌酶学检查；并应用免疫荧光技术，对其中４９例ＭＧ患者测定抗骨骼肌抗心肌抗体（ＳＨ－Ａｂ）。以正常人作对照检查。结果心电图异常率３０．３５％，超声心动图异常率１０．７１％，心肌酶学异常率４１．０７％。ＳＨ－Ａｂ阳性率４８．９％，对照组无１例有ＳＨ－Ａｂ。还发现伴心肌酶异常的ＭＧ患者ＳＨ－Ａｂ阳性率６９．６％（１６／２３），心肌酶正常的患者ＳＨ－Ａｂ阳性率仅为３０．８％（８／３０），伴胸腺瘤者（ＭＧＴ）ＳＨ－Ａｂ阳性率为４１．６％（５／１２），不伴胸腺瘤者（ＭＧＮＴ）ＳＨ－Ａｂ阳性率仅为２４．３２％（９／３７）。另外，ＭＧＴ心电图、心肌酶学异常率均为５０％，均明显高于ＭＧＮＴ。结论ＭＧ的心脏损害可能与ＳＨ－Ａｂ滴度增高抗原抗体结合等自身免疫机制有关。

Objective To detect the mechanism of heart involvement in patients with MG. Methods The 56 patients with MG and 25 controls were examined by the injury free heart examinations including EKG, Color Doppler Ultrasonic Cardiogram and Myocardial Enzyme. skeletal and heart antibodies (SH Ab) were measured by immunofluorescence in serum for 49 MG patients, 42 controls. Results EKG abnormal rate was 30 35%, Ultrasonic Cardiogram abnormal rate was 30.35%, Myocardial Enzyme abnormal rate was 41.07% and SH Ab positive was 48.9%. Among the controls, none had SH Ab. It was significantly related between the injury free heart examinations abnormal rate and SH Ab positive rate. The positive rate of SH Ab was 69.6% (16/23) in the MG patients with high Myocardial Enzyme and 30.8% (8/30) in the MG patients with normal Myocardial Enzyme. The positive rate of SH Ab was 41.6% (5/12) in the MG patients with thymoma (MGT) and 24.32% (9/37) without thymoma (MGNT). Conclusion The heart involvement in patients with MG may be related with the autoimmune mechanism of antigens and antibodies combination.