Bossi Vincenzo, Galli Claudio
Virology, Ospedale Amedeo di Savoia, corso Svizzera 164, 10100 Turin, Italy.
J Clin Virol. 2004 May;30(1):45-9. doi: 10.1016/j.jcv.2003.08.007.
The diagnosis of ongoing hepatitis C virus (HCV) infection involves the detection of specific antibodies and of HCV-RNA. We aimed to assess the relationship between these two parameters in a representative sample of a population at high risk for HCV infection.
Plasma and serum samples were respectively tested for HCV-RNA by a qualitative PCR (Cobas Amplicor HCV, Roche) and for HCV antibodies by a MEIA screening assay (AxSYM HCV 3.0, Abbott) and an immunoblot (Inno-LIA-III, Innogenetics).
Out of 888 samples assayed, 579 (65.2%) were positive for HCV-RNA, while anti-HCV antibodies were detected respectively in 802 sera by AxSYM (90.3%) and in 783 by LIA (706 positive and 77 indeterminate, 88.2%). The anti-core antibodies displayed the best correlation with viremia, since they were present in 97.1% of the PCR+ samples, followed by anti-NS3 (90.2%) and anti-NS4 (89.6%). Only one HCV-RNA positive sample was negative by LIA and MEIA (early seroconversion). The AxSYM sample/cutoff (S/CO) values were directly correlated with the presence of HCV-RNA: a PCR positivity was found in 4.9% of samples with a S/CO < or =10, in 60.8% of samples with a S/CO between 11 and 50 and in 93.6% of cases with a S/CO >50, (P < 0.005). The immunoblot adds little, on a single specimen, to the information yielded by the AxSYM screening test. A suitable diagnostic algorithm for HCV in high-risk settings could be the anti-HCV screening by MEIA and a qualitative assay for HCV-RNA on samples with low reactivity.
持续性丙型肝炎病毒（HCV）感染的诊断涉及特定抗体及HCV-RNA的检测。我们旨在评估在HCV感染高危人群的代表性样本中这两个参数之间的关系。
分别采用定性聚合酶链反应（Cobas Amplicor HCV，罗氏公司）检测血浆和血清样本中的HCV-RNA，采用微粒子酶免疫分析筛查法（AxSYM HCV 3.0，雅培公司）及免疫印迹法（Inno-LIA-III，Innogenetics公司）检测HCV抗体。
在检测的888份样本中，579份（65.2%）HCV-RNA呈阳性，而AxSYM法在802份血清中检测到抗-HCV抗体（90.3%），LIA法在783份血清中检测到抗-HCV抗体（706份阳性，77份不确定，88.2%）。抗核心抗体与病毒血症的相关性最佳，因为在97.1%的PCR阳性样本中存在该抗体，其次是抗NS3（90.2%）和抗NS4（89.6%）。仅1份HCV-RNA阳性样本经LIA和微粒子酶免疫分析呈阴性（早期血清转化）。AxSYM样本/临界值（S/CO）值与HCV-RNA的存在直接相关：S/CO≤10的样本中4.9%呈PCR阳性，S/CO在11至50之间的样本中60.8%呈PCR阳性，S/CO>50的样本中93.6%呈PCR阳性（P<0.005）。就单个样本而言，免疫印迹法所提供的信息相比AxSYM筛查试验增加甚少。在高危环境中，一种合适的HCV诊断算法可能是采用微粒子酶免疫分析进行抗-HCV筛查，并对反应性低的样本进行HCV-RNA定性检测。
