摘要:
目的 探讨乙酰胆碱受体抗体(AChR-Ab)与重症肌无力(MG)临床特征的相关性.方法 采用放射免疫法检测11 5例MG患者及92例对照组(非MG神经系统疾病患者42例,健康体检者50名)血清AChRAb浓度,应用临床绝对评分记录MG患者病情严重程度.分析各组血清AChR Ab浓度的差异,以及AChR Ab浓度与MG患者临床特征的相关性.采用ROC工作特征曲线探讨AChR Ab诊断MG的敏感度和特异度.结果 MG患者血清AChR Ab浓度中位数(四分位数间距,下同)为3.45(39.38)nmol/L,较非MG神经系统疾病患者[0(0) nmol/L]和健康体检者[0 (0) nmol/L]增高(P<0.01).全身型MG(GMG)患者AChR-Ab浓度[25.45(46.14)nmol/L]较眼肌型MG(OMG)患者[0.58(3.56)nmol/L]增高(P<0.01).用ROC曲线法分析显示,以血清AChR Ab浓度≥0.50 nmol/L作为诊断MG界值时灵敏度为72.17%,特异度为100%,曲线下面积(AUC) =0.895(95%CI:0.849~0.941).AChR-Ab浓度与发病年龄、病程及改良Osserman分型呈正相关(r=0.220,P<0.05;r=0.184,P<0.05;r=0.382,P<0.01),但相关性较弱(均r<0.5),与临床绝对记分无相关性(r=0.147,P>0.05).结论 用放射免疫法检测血清AChR-Ab浓度诊断MG的灵敏度和特异度均高,有助于减少MG的漏诊率及误诊率,值得临床推广.%Objective To investigate the clinical correlations between the acetylcholine receptor antibody (AChR-Ab) level and myasthenia gravis (MG).Methods Radioimmunoassay is used to detect serum AChR-Ab level of 115 MG patients and 92 control (42 patients with non MG neurological disease and 50 healthy subjects).Clinical absolute score was used to record the severity of MG.Results The data was expressed as median (interquartile range).In patients with MG,the serum AChR-Ab titer was 3.45 (39.38) nmol/L,which was higher than non MG neurological patients [0 (0) nmol/L] and the healthy subjects [0 (0) nmol/L] (P< 0.01).In generalised type MG (GMG),the AChR-Ab titer [25.45 (46.14) nmol/L] was higher than oculartype MG (OMG) patients [0.58 (3.56) nmol/L] (P<0.01).Obtained by ROC curve method:using the serum AChR-Ab titer ≥0.50 nmol/L as the diagnostic cutoff value,sensitivity was 72.17%,and specificity was 100%,the area under the curve was 0.895 (95% CI:0.849-0.941).AChR-Ab titer was associated with age of onset,disease duration and modified Osserman type (r=0.220,P<0.05;r=0.184,P<0.05;r=0.382,P<0.01),whereas the clinical absolute scores was not correlated (r=0.147,P>0.05).Conclusions With radioimmunoassay method to detect the serum AChR-Ab titer,the sensitivity and specificity of the diagnosis of MG are both high,thus this technique helps to reduce misdiagnosis of MG,to distinguish OMG from GMG and predict the OMG transformation to GMG.