丙型肝炎病毒抗体酶联免疫吸附试验阳性判断值在献血员血液筛检中的意义

目的探讨丙型肝炎病毒(HCV)抗体酶联免疫吸附试验(ELISA)测定阳性判断值(Cut-off)“灰区”在献血员血液筛检中的应用价值。方法采用逆转录-聚合酶链反应(RT-PCR)方法检测了503份抗-HCV ELISA测定为阴性的献血员血清(浆)标本的HCV RNA。如HCV RNA检测为阳性，则使用重组免疫印迹(RIBA)方法进一步检测抗HCV。结果在503份抗-HCV ELISA阴性献血员血清(浆)标本中，发现有5份HCV RNA阳性，其中2份标本抗HCV ELISA测定S/CO比值小于0．5，RIBA结果均为阴性。另外3份抗HCV阴性(ELISA检测的S/CO值在0．8-0．9之间)但HCV RNA为阳性的献血员血标本，进一步进行RIBA检测，发现其中2份为抗核心区(C22)单独阳性，另外1份为抗NS3单独阳性。阳性标本HCV RNA的含量测定均约为10^4拷贝/ml。结论为尽可能减少输血后HCV感染的发生，有必要将抗-HCV ELISA测定的Cut-off值下移20％，因为S/CO比值接近Cut-off值的血液有很大可能为HCV感染者。

Significance of the cut-off value of anti-HCV ELISA in screening of blood donors

Objective Tode termine applicati onvalue oft hegray zon eofanti HCV ELISA cut off insc reenin gofbloo ddonors Methods The 5 0 3an ti HCVEL ISA negati veserumorp lasmaof donors weret estedf orHCVR NAbyRT PCR IfHCVRN Awere posi tive ,the anti HCV recomb inanti mmuno blo tassay (RIBA)co nfirma tionte stwould becar riedout Results Therew erefive HCVRN Apos itive among 5 0 3samples,wher etheanti HCVELISA S/COvalues oftwo HCVRNAposit ivesampleswe reless than 0 5andresu ltsofR IBAwere negative Othert hrees amplesw ithHC VRNA p ositi ve butanti HCV negative (S/CObyE LISAwe rebe tween 0 8and 0 9)wer efurthert estedby RIBA There sultss howed thatt woofthreesa mpl esw ereanti C2 2 positi veandanot heron ewasan ti NS3p ositive Theq uant itative detectionofHC VRNAsh owedthatthe am ountofHCVRNAofthepositivesampl eswere about 10 4 copies/ml Conclusion Itisnecessarytodecreasethecut offvalue (S/CO)ofanti HCVELISAto 0 8 inordertoreducetheriskofpost transfusi onHCV infection because odunits fromdono rswithanti HC VELISAne gative (S/CO valu enearby 1 0 )butHC VRNAp ositive