两种CLIA系统检测梅毒抗体的一致性及临界值设置

Consistency and cutoff value set for two chemiluminescence systems for detection of syphilis antibody

目的观察不同化学发光(CLIA)系统检测梅毒(TP)抗体与梅毒螺旋体明胶颗粒凝集试验(TPPA)的一致性并设定临界值。方法以博阳LICA500检测抗TP抗体S/CO>1.0的血清样本296例﹑S/CO<1.0的血清样本50例;同时以雅培i2000SR复检,以TPPA法进行确认检验。以TPPA为标准,方法间一致性比较采用Kappa检验;以TPPA为标准,绘制抗TP抗体S/CO比值受试者工作特征曲线(ROC曲线),得到约登指数最大时的S/CO比值以设定其临界值。结果雅培i2000SR抗TP抗体与TPPA检测结果的一致性较好(Kappa=0.826),博阳LICA500抗TP抗体与TPPA检测结果的一致性较差(Kappa=0.438);两者抗TP抗体与TPPA结果间的差异均具有显著性(P<0.05)。雅培i2000SR检测抗TP抗体的灵敏度为100%,特异度为82.8%,阳性预测值为88.9%,阴性预测值为100%;而LICA500检测抗TP抗体的灵敏度为100%,特异度为61.9%,阳性预测值为73.0%,阴性预测值亦为100%。ROC曲线分析显示,博阳LICA500和雅培i2000SR检测抗TP抗体的曲线下面积分别为0.986和0.989;博阳LICA500抗TP抗体最佳诊断界值为10.095,其灵敏度为96.8%,特异度为97.5%;雅培i2000SR抗TP抗体最佳诊断界值为3.02,其灵敏度为95.8%,特异度为100%。结论不同化学发光系统检测梅毒抗体的诊断效能有差异,各实验室应设置最佳诊断界值并验证后使用。

Objective To observe the consistency of different chemiluminescence(CLIA)systems and TPPA in the detection of syphilis(TP)antibodies and to set the cutoff value.Methods 296 serum samples with anti-TP antibody S/CO>1.0 and 50 serum samples with S/CO<1.0 were tested by Boyang LICA500,and then retested by Abbott i2000 SR,with the results confirmed by treponema pallidum particle agglutination test(TPPA).TPPA used as standard,Kappa test was conducted to compare the consistency between the two.The ROC curve of S/CO ratio of anti-TP antibody was drawn,and the S/CO ratio at the time of maximum Jordan index was obtained to set its cutoff value.Results The results of anti-TP antibody detected by Abbott i2000 SR and TPPA were in good agreement(kappa=0.826),and the consistency between anti-TP antibody detected by Boyang LICA500 and TPPA results was poor(kappa=0.438).The difference of the results between the anti-TP antibody and TPPA was significant(P<0.05).The sensitivity of Abbott i2000 SR for detecting anti-TP antibody was 100%,with 82.80%specificity,88.89%positive predictive value,and 100%negative predictive value.The sensitivity of LICA500 for detecting anti-TP antibody was 100%,with 61.90%specificity,72.97%positive predictive value,and 100%negative predictive value.ROC analysis showed that the area under the curve of anti-TP antibody detected by Boyang LICA500 and Abbott i2000 SR was 0.986 and 0.989,respectively.The optimal diagnostic threshold of Boyang LICA500 anti-TP antibody was 10.095,with 96.8%sensitivity,and 97.5%specificity.The optimal diagnostic threshold of Abbott i2000 SR anti-TP antibody was 3.02,with 95.8%sensitivity,and 100%specificity.Conclusion Different chemiluminescence systems have different diagnostic efficiency for detection of syphilis antibodies.Each laboratory should set a cutoff value and verify it for use.