HBsAg ELISA+/HBV DNA NAT-献血者血清学与分子生物学特征分析

Serological characteristics of HBsAg positive/HBV DNA non-reactive blood donors

目的 了解西安地区无偿献血人群HBsAg ELISA检测结果与HBV DNA检测结果不一致的标本相关血清学标志物的分布情况。方法 收集2022年11月1日—2023年4月30日陕西省血液中心HBsAg ELISA+/HBV DNA NAT-(ELISA+/NAT-)标本共计71份,对其采用电化学发光法检测乙肝血清学标志物,同时复检巢式PCR扩增HBV S区和C区基因片段。结果 双ELISA+/NAT-标本(n=30)巢式PCR检测阳性率远高于单ELISA+/NAT-标本(n=41)(60%vs 24.40%,P<0.05)。前者献血者100%为初次献血者,血清抗-HBc阳性率100%,血清学模式以1、4、5此3项阳性(80%)为主;后者献血者中31.7%为重复献血者,血清抗-HBc阳性率仅为19.51%,血清学模式以单2项阳性(43.90%)和全阴(36.58%)为主。结论 单ELISA+结果存在较多假阳性,导致不必要的血液报废;而NAT-标本可能存在低水平的HBV DNA,产生漏检风险。建议针对单HBsAg ELISA+/NAT-献血者,采用多套系统多种方法追溯检测,提高献血者HBV筛查的准确度,减少不必要的血液浪费。

Objective To explore the distribution of serological markers related to samples whose serological test results were inconsistent with HBV DNA test results among voluntary blood donors in Xi′an.Methods A total of 71 HBsAg ELISA positive and NAT non-reactive(ELISA+/NAT-)blood samples were collected from Shaanxi Blood Center from November 1,2022 to April 30,2023.The serological markers of hepatitis B were detected by electrochemiluminescence method,and the HBV S region and C region gene fragments were amplified by nested-PCR.Results The positive rate of nested-PCR in double ELISA+/NAT-group(n=30)was statistically higher than that of ELISA+/NAT-group(n=41)(60%vs 24.4%,P<0.05).Donors in double ELISA+/NAT-group were all first-time blood donors,with the positive rate of anti-HBc in serum of 100%,and the serological pattern was mainly positive for items 1,4 and 5 items(80%).Among the ELISA+/NAT-group,31.7%were repeat blood donors,with the positive rate of anti-HBc in serum of only 19.51%,and the serological patterns were mainly single anti-HBs positive(43.90%)and all negative(36.58%).Conclusion There are false positives in the test results of ELISA+/NAT-group,which leads to unnecessary blood discarding.Meanwhile,the samples with negative NAT may have low levels of HBV DNA,which may lead to missed detection.It is suggested that multiple systems and methods should be applied to trace the blood donors who are HBsAg positive and NAT non-reactive,so as to improve the accuracy of HBV screening of blood donors and reduce blood waste.