珠海市无偿献血者梅毒ELISA不合格结果与TPPA确证实验的对比分析

Comparative analysis of unqualified results of syphilis ELISA and TPPA confirmatory test among blood donors in Zhuhai City

目的:分析无偿献血者梅毒酶联免疫吸附(ELISA)不合格的螺旋体颗粒凝聚实验(TPPA)确证,明确灰区限设置的必要性和合理性以及研究初筛实验S/CO值与梅毒确证分级结果的相关性。方法:收集本地区梅毒螺旋体ELISA检测不合格标本589份,采用TPPA法进行确证实验。结果:ELISA检测不合格血液标本589份,经TPPA法检测阳性380份,阴性209份,ELISA法假阳性率为35.48%;ELISA初次双试剂检测结果S/CO值均>3,阳性符合率为95.70%(356/372);双试剂反应性其中一种试剂检测结果S/CO值≤3,阳性符合在确证阳性的380份标本中,ELISA双试剂反应性的是360份(94.74%),18份呈ELISA的是4份(36.36%);单试剂反应性中,ELISA检测范围灰区值中的有2份。结论:在此次筛查实验中,存在部分假阳性的问题,为了避免血源浪费,可考虑对不合格的样本进行TPPA确证实验,同时还应该在检测时设置合理的灰区范围,可有效降低输血传播梅毒的风险,梅毒抗体酶联免疫吸附实验S/CO值的高低和确证实验分级结果存在正相关性。

Objective:To analyze the substandard Treponema pallidum particle agglutination test(TPPA)confirmation in unpaid blood donors with unqualified syphilis enzyme-linked immunosorbent assay(ELISA),to clarify the necessity and rationality of setting the gray limit,and to study the correlation between the S/CO value of primary screening test and the results of syphilis confirmation classification.Methods:589 unqualified samples of Treponema pallidum ELISA detection in local area were collected,TPPA method was used to confirm the experiment.Results:Among 589 unqualified blood samples detected by ELISA,380 were positive by TPPA method,209 were negative,the false positive rate of ELISA was 35.48%.The S/CO value of the ELISA first double reagent was more than 3,and the positive coincidence rate was 95.70%(356/372).The S/CO value of one of the reagents in double reagent reactivity was less than or equal to 3,in 380 confirmed positive samples,the double reagent reactivity of ELISA was also positive in 360(94.74%),4 cases(36.36%)showed ELISA in 18 samples.In the single reagent reactivity,the detection range of ELISA was in the gray area in 2 samples.Conclusion:In this screening experiment,there are some false positive problems,in order to avoid the waste of blood source,TPPA confirmatory test can be carried out on unqualified samples,at the same time,a reasonable gray area should be set during the detection,which can effectively reduce the risk of transfusion transmitted syphilis,there was a positive correlation between the S/CO value of ELISA and the results of confirmatory test.