广州医科大学学报

目的:评价化学发光微粒子免疫测定法(CMIA)、梅毒螺旋体明胶颗粒凝集试验(TPPA)及ELISA在梅毒抗体检测中的表现及阳性符合率,探讨化学发光检测特异性梅毒抗体S/CO的最佳诊断截断值与其影响因素。方法:收集雅培I2000化学发光免疫分析仪抗T.pallidum阴性标本(S/CO<1)118例、阳性标本(S/CO>=1)237例。分别用梅毒螺旋体明胶凝集试验(TPPA)和酶联免疫吸附法(ELISA)对样本进行抗T.pallidum复查检测,并对TPPA阴性样本进行抗核抗体及类风湿抗体IgG检测,并分析CMIA与TPPA不相符样本的临床特征。以TPPA结果为参考标准,比较CMIA与ELISA的特异性、敏感性等,受试者工作曲线分析CMIA在本实验室的最佳截断值。结果:以TPPA为标准,CMIA的敏感性、特异性分别为100%和75.6%,ELISA的敏感性、特异性分别为99.5%和87.8%。用ROC曲线分析CMIA最佳临界值为S/CO=2.56,ROC曲线下面积达到最大为0.992。TPPA-CMIA+与TPPA-CMIA+两组的抗核抗体及类风湿因子检测差异均有统计学意义(P<0.05)。CMIA+TPPA-的样本人群特点为老年人及不孕的育龄女性。结论:CMIA的临界值为2.56时,可提高本实验室的特异性。当患者有特定疾病且CMIA结果偏低时采用TPPA辅助诊断并及时沟通病史、定期复查。

Objective:To evaluate the performance and positive coincidence rate of chemiluminescence microparticle immunoassay(CMIA),Treponema pallidum gelatin particle agglutination assay(TPPA)and enzyme-linked immunosorbent assay(ELISA)in detection of syphilis antibodies,and to explore the diagnostic CO value in CMIA for specific syphilis antibodies.MethodsIncluded in this study were 118 T. pallidum negative(S/CO<1)and 237 T. pallidum positive specimens(S/CO≥1)confirmed by CMIA(Abbott I2000 analyzer). TPPA and ELISA were used to test the samples for T. pallidum antibodies.TPPA-negative samples were further detected for anti-nuclear antibody and rheumatoid antibody IgG. The clinical characteristics of the samples with inconsistent CMIA and TPPA findings were analyzed. Using TPPA findings as the reference,the specificity and sensitivity of CMIA vs ELISA were compared. Receiver operating curve was used to determine the optimal cut-off value for CMIA in our laboratory.ResultsWith TPPA as the reference,the sensitivity and specificity of CMIA were 100% and 75.6%,respectively,compared with 99. 5% and 87. 8%,respectively,by ELISA. The ROC curve analysis showed with an optimal S/CO cut-off value of 2.56,the area under ROC curve reached a maximum of 0.92. There were statistically significant differences in tests for antinuclear antibody and rheumatoid antibody IgG between the TPPA-CMIA+ and TPPA+CMIA-samples(P<0.05).The demographic characteristics of CMIA+TPPA-samples were of elderly and infertile women of childbearing age.ConclusionA S/CO cut-off of 2.56 in CMIA can improve specificity in our laboratory. Patients with specific diseases and a low CMIA value should be subject to adjuntive diagnostic attempt with TPPA,timely inspection of medical history,and regular follow-ups.