HBsAg双试剂检测结果不一致的献血者HBV感染分析

摘要

目的 研究HBsAg双试剂ELISA检测结果不一致的献血者中HBV感染发生率并分析HBV DNA阳性标本单试剂检测失败的发生原因.方法 收集30例血清学HBsAg双试剂检测结果不一致的献血者血浆标本,采用实时定量PCR进行HBV DNA含量检测.对于HBV DNA定量阳性的标本,PCR扩增HBV pre-S/S区基因,并进行克隆测序.结果 22例标本试剂1检测为阳性(S/CO:3.05 ±1.78)而试剂2检测为阴性(S/CO:0.21±0.22),8例标本试剂1检测为阴性(S/CO:0.11±0.06)而试剂2检测为阳性(S/CO:2.43±1.29).上述30例标本中,仅4例标本HBV DNA定量结果大于103拷贝/ml,占13.3％.这4例标本中2例测序失败,2例得到pre-S/S区测序结果,其中1例标本存在pre-S缺失突变,1例标本存在S基因“a”决定簇内126和135位点突变.结论 不同厂家HBsAg酶联免疫法诊断试剂盒敏感性和特异性不同,个别献血者会出现双试剂检测结果不一致,其中少数存在HBV感染.HBsAg血清免疫学方法单试剂的漏检可能与HBV S基因突变有关.献血者双试剂检测对血液安全性至关重要,HBV核酸检测的推广可减少隐匿性HBV感染对输血安全造成的威胁.%Objective This study was designed to explore the incidence rate of HBV infection in donors with different HBsAg ELISA test results by two kits and analyze the possible reasons of detection failure by single reagent.Methods Plasma of 30 donors with inconsistent HBsAg results were collected and real-time PCR was used to detect HBV DNA.For HBV DNA positive samples,HBV pre-S/S amplification products were obtained by PCR,and then clonal sequencing were used.Results Twenty-two samples were detected positive by reagent 1 (S/CO:3.05 ± 1.78) while negative by reagent 2 (S/CO:0.21 ± 0.22),eight samples were detected negative by reagent 1 (S/CO:0.11 ± 0.06) while positive by reagent 2 (S/CO:2.43 ± 1.29).Four samples were greater than 103 copies / ml in these 30 samples,with a fraction of 13.3％.Pre-S/S sequencing results of two samples from these four samples were obtained and the other two failed.Pre-S deletion mutations were found in one sample and 129 and 135 point mutations within " a" determinant were detected in another sample.Conclusions HBsAg ELISA diagnostic kits by different manufacturers have different sensitivity and specificity,so the results of special donors may show inconsistent,in which the minority has HBV infection.The failure of HBsAg serological methods by a single reagent may be associated with HBV S gene mutations.Detections of donors with double reagents are critical to the transfusion safety.HBV DNA detection can reduce the threat for transfusion safety due to occult HBV infection of blood donors.