免疫筛查阴性献血者血样病毒核酸检测的研究

目的了解二次酶联免疫筛查献血者血样漏检的原因。方法将二次酶联免疫筛查阴性的献血者血样在加样仪上实现血液样本汇集,用全自动核酸提取仪提取样本核酸,以核酸扩增检测仪做HBV、HCV和HIV自动扩增检测。对HBsAg阴性、HBVDNA阳性献血者用核酸筛查试剂定量检测HBV,并每隔2周对其跟踪采血,做HBV两对半免疫检测和HBsAgV3的确认试验。结果16320份二次酶联免疫筛查阴性的合格献血者血样中,8份HBVDNA阳性(漏检率0.49‰),未发现HCV和HIV1RNA阳性。8份HBVDNA阳性献血者乙肝两对半免疫检测HBsAg、HBsAb和HBeAg均为阴性,HBcAb均为阳性,3份HBeAb为阳性。6例HBsAg阴性HBVDNA阳性献血者血样的病毒滴度在(76～1490)copies/ml,2例病毒滴度过低,未定量检测到病毒。跟踪6名HBVDNA阳性献血者,1例18周时HBsAg确认试验阳性,其余5例仍为阴性。结论现行的二次酶联免疫技术的血液筛查存在HBV漏检,原因可能是隐匿性乙型肝炎病毒感染。应重视血液筛查工作中HBV的漏检及输血传播,并在现有的血液筛查模式中或增加HBcAb检测,或增加病毒核酸筛查。

NAT testing for HBV,HCV,HIV on donors' samples negative by ELISA tests

Objective To perform NAT testing on samples negative for HBsAg, anti-HCV and anti-HIV by ELISA, and to learn how many infected blood samples could be missed by ELISA tests.Methods Pooling the donor samples by STAR2000 sampling processor and extracting nucleic acid automatically, HBV DNA, HCV RNA and HIV-1 RNA were amplified and detected by Roche COBAS AmpliScreen TM HBV、HCV V2.0 和HIV-1 V1.5 systems. Samples of 8 donors with negative HBsAg but positive HBV DNA were tested by COBAS HBV MONITOR TM for quantitative determinations. HBsAg confirmation tests were done every 2 weeks by ABBOTT Murex HBsAg V3.Results A total of 16320 ELISA negative donor samples were tested and 8 samples were HBV DNA positive. The missing rate was 0.49‰. No HCV RNA and HIV-1 RNA were detected. Those 8 donor samples, negative for HBsAg but positive for HBV DNA,were all positive for HBcAb by ABBOTT,and 3 of them were positive for HbeAb Low serum HBV DNA loads, in the range of 102~103 copies/ml, were found in the 8 donor samples. HBsAg confirmations were performed and one donor became HBsAg positive after 18 weeks.Conclusion The results show that there is 0.49‰ missing rate of HBV with HBsAg screening by ELISA. HBcAb screening or NAT may be warranted in blood donor screening to limit HBV transmission through blood transfusion.The reason for missing HBV positive samples by ELISA could be occult HBV infection.