联合检测重症肌无力的三种血清抗体诊断

摘要

目的 对重症肌无力(MG)患者的乙酰胆碱受体抗体(AchR-Ab)、连接素抗体(Titin-Ab)和肌肉特异性酪氨酸激酶抗体(MuSK-Ab)评价该3种血清抗体联合检测对MG的诊断价值.方法 选择MG组患者112例、其他疾病对照组53例和健康对照组56例,采用放射免疫法测定AchR-Ab,ELISA法分别测定Titin-Ab和MuSK-Ab,并对结果进行分析.结果 MG患者AchR-Ab、Titin-Ab和MuSK-Ab的阳性率分别为68.8％、54.5％和5.4％,明显高于对照组(P＜0.05).三种抗体联合检测,其敏感性和特异性分别为91.1％和89％.其中,MuSK-Ab仅见于AchR-Ab阴性的MG患者,主要表现为延髓肌受累,病情较重且不伴有胸腺病变.Titin-Ab多见于MG合并胸腺瘤(MGT)患者,其MGT组的阳性率高于未合并胸腺瘤的MG(NTMG)患者(P＜0.05).将MG患者根据Osserman评分进行分型,Titin-Ab阳性率与病情严重程度有关(P＜0.05).结论 AchR-Ab、Titin-Ab、MuSK-Ab三种抗体是MG的诊断性标记抗体,联合检测可以避免因单项检测出现的漏诊和误诊,此外,Titin-Ab对MG合并胸腺瘤具有显著相关性,还可作为判断MG病情严重程度的指标.%Objective To detect the acetylcholine receptor antibodies (AchR-Ab),connecting element (Titin-Ab) and muscle specific tyrosine kinase antibody (MuSK-Ab) for the clinical diagnosis and treatment of myasthenia gravis (MG).Method Select one hundred and twelve cases of patients with MG group and control group of fifty-three cases of other diseases and health control group fifty-six cases,AchR-Ab was evaluated by radioimmunity method,while Titin-Ab and MuSK-Ab were detected by ELISA respectively.The results were analyzed.Results AchR-Ab,Titin-Ab and MuSK-Ab positive rate were 68.8％,54.5％ and 5.4％ in myasthenia gravis,significantly higher than control group (P＜ 0.05).Sensitivity and specificity of joint detection were 91.1％ and 89％respectively.MG patients with the MuSK-Ab restricted to AchR-Ab negative main involved the medulla oblongata muscle,they were heavier and without thyrmus pathological changes.Titin-Ab of MG patients with thymoma (MGT)were higher than that of MG patients without thymoma (P＜0.05).According to the Osserman score,Titin-Ab positive rate of MG were associated with disease severity (P＜0.05).Conclusion AchR-Ab,Titin-Ab and MuSK-Ab were a diagnostic markers of MG patients.The joint detection can avoid missed diagnosis and misdiagnosis.In addition,Titin-Ab of MG combined thymoma might be has significant correlation and as a judge index of illness severity.