Objective: To Establish the shielding threshold value of TP antibody ELISA for unpaid blood donors, so as to shield true positive blood donors from returning to team management.
Methods: The real serological status of 517 samples with anti-TP ELISA reactivity was determined by confirmation test of Treponema pallidum particle agglutination (TPPA). The shielding threshold of TP antibody was preliminarily determined by using 99% specificity of ROC and 95% positive predictive value of percentile method, respectively. 283 TP antibody reactivity specimens routinely tested in our laboratory were selected to determine the applicability of the initial shielding values obtained by the two methods, and finally to determine the shielding threshold values of TP antibody donors.
Results: The specific S/CO values of reagent A 99% were 13.33-16.18, that of reagent B 99% was 6.34, that of reagent B 99% was 13.17-19.85, and that of 95% was 6.62. Empirical evidence: 99% specific threshold shielding true positive rates of reagents A and B were 100%, 95% positive expected value shielding true positive rates were 98.4%, 99%. Final determination of 99% specific shielding threshold as a low value of blood donors shielding threshold. The shielding limits of reagent A and B were 13.33 and 13.17.
Conclusion: The shielding threshold of TP antibody ELISA for blood donors established in this study can help to reduce the number of blood donors returning to team management.
题目: 献血者TP抗体 ELISA检测屏蔽界限的探讨.
目的: 建立无偿献血者TP抗体 ELISA检测屏蔽界限值，以此屏蔽真阳性献血者进入归队管理.
方法: 通过对本实验室常规检测的 517 份抗TP ELISA反应性的标本进行梅毒螺旋体颗粒凝集（TPPA）确证试验，确定标本的真实血清学状态。分别使用受试者工作曲线（ROC）99%特异性和百分位数法95%阳性预期值初步确定TP抗体屏蔽界限值。选择本实验室常规检测的283份TP抗体反应性标本，判断两种方法得出的初步屏蔽值的适用性，最终确定TP抗体献血者的屏蔽界限值.
结果: 试剂A 99%特异性对应S/CO值为13.33-16.18，95%百分位数法对应S/CO值为6.34；试剂B 99%特异性对应S/CO值为13.17-19.85，95%百分位数法对应S/CO值为6.62。经验证，试剂A、B的99%特异性界值屏蔽真阳性率均为100%；95%阳性预期值屏蔽真阳性率分别为98.4%、99%。最终确定99%特异性屏蔽界限低值作为献血者屏蔽界限值；试剂A的屏蔽界限为13.33，试剂B屏蔽界限为13.17.
结论: 本研究建立的献血者TP抗体 ELISA检测的屏蔽界限值有助于减少进入后续献血者归队管理的数量.