化学发光法和TPPA试验检测梅毒抗体的比较及阳性符合率分析

Comparison of Chemiluminescent Assay and TPPA Test in Detecting Syphilis Antibody and Analysis of Positive Coincidence Rate

目的评价化学发光微粒子免疫测定(CMIA)法和梅毒螺旋体明胶颗粒凝集试验(TPPA)试验在梅毒抗体检测中的表现及阳性符合率。方法对809例受检者同时进行CMIA法和TPPA检测,以TPPA试验为金标准,计算CMIA法的灵敏度、特异度等指标及其与TPPA试验的阳性符合率。对CMIA法S/CO值绘制ROC曲线,确定CMIA法对梅毒诊断效能最大时的S/CO截断值。结果 CMIA法检测阳性率为40.42%,TPPA试验检测阳性率为36.34%,二者差异无统计学意义。CMIA法的灵敏度为97.96%,特异度为92.43%。CMIA法与TPPA试验的阳性符合率为88.07%,CMIA法的S/CO值越小,其与TPPA试验的阳性符合率越低。ROC曲线分析CMIA法S/CO的最佳诊断截断值为4.98,敏感度和特异度分别为83.71%和94.93%。此外受检者年龄越大,两种方法的阳性符合率越低,60岁以上者两种方法的阳性符合率显著低于60岁以下者。结论 CMIA法的诊断效能与TPPA试验接近,是较好的梅毒筛查方法。应用CMIA法对低值标本和老年人标本进行梅毒特异性抗体检测时须警惕假阳性结果,必要时进行TPPA检测以确保结果准确。当CMIA法S/CO截断值设定为4.98时,可获得最大诊断效能。

Objective In order to evaluate the performance and positive coincidence rate of CMIA and TPPA test in syphilis antibody test. Methods Totally 809 subjects were tested by CMIA and TPPA at the same time,and the TPPA test was the gold standard. The sensitivity and specificity of CMIA and the positive coincidence with the TPPA test were calculated. The ROC curve was made with S/CO value of CMIA,and the S/CO cut-off value of CMIA was determined to obtain maximum diagnostic efficiency in diagnosis of syphilis. Results The positive rate of CMIA was 40.42%,and the positive rate of TPPA test was 36.34%. There were no statistical differences between them. The sensitivity of CMIA was 97.96%,and the specificity was 92.43%. The positive coincidence rate between CMIA and TPPA test was 88.07 %. The smaller the S/CO value of CMIA,the lower the positive coincidence rate with TPPA test. ROC curve analysis showed that the best S/CO cut-off value of CMIA was 4.98,sensitivity and specificity were 83.7% and 94.9%,respectively. The greater the age of the subjects,the lower the positive coincidence rate of two methods. The positive coincidence rate of two methods was significantly lower in subjects over the age of 60 than that of those under the age of 60. Conclusion The diagnostic efficiency of CMIA is close to that of TPPA test. CMIA is a good method for syphilis screening. We should be alert to false positive results when using CMIA to detect syphilis specific antibody in low value specimens and elderly people. If necessary,TPPA test will be performed to ensure the accuracy of the results. When the S/CO cut-off value of CMIA is set to 4.98,the maximum diagnostic efficiency can be obtained.