Gretch D R
Department of Laboratory Medicine, University of Washington Medical Center, Seattle 98195, USA.
Hepatology. 1997 Sep;26(3 Suppl 1):43S-47S. doi: 10.1002/hep.510260708.
Diagnostic tests for hepatitis C can be divided into the following two general categories: 1) serological assays that detect antibody to hepatitis C virus (anti-HCV); and 2) molecular assays that detect, quantify, and/or characterize HCV RNA genomes within an infected patient. Serological assays have been subdivided into screening tests for anti-HCV, such as the enzyme immunoassay (EIA), and supplemental tests such as the recombinant immunoblot assay (RIBA). Three generations of anti-HCV tests have been developed, and each generation has resulted in an improvement in the sensitivity of detecting anti-HCV. Supplemental anti-HCV tests are designed to resolve false-positive testing by EIA, and are appropriately used in low-prevalence settings in which false-positive anti-HCV tests remain a problem. Third-generation anti-HCV tests (EIA-3 and RIBA-3, respectively) contain antigens from the HCV core, nonstructural 3, nonstructural 4, and nonstructural 5 genes. Detection of HCV RNA in patient specimens by polymerase chain reaction (PCR) provides evidence of active HCV infection and is potentially useful for confirming the diagnosis and monitoring the antiviral response to therapy. Optimal HCV PCR assays at present have a sensitivity of less than 100 copies of HCV RNA per milliliter of plasma or serum. Standardization and proficiency testing of diagnostic laboratories performing HCV PCR remains an important problem for future study. Two main technologies exist for assessing HCV RNA levels or viral load. Quantitative PCR is the most sensitive test for determining hepatitis C viral load, whereas the branched-chain DNA test appears to be the most precise method. Major limitations of the current tests are inadequate dynamic range and high variability of PCR-based assays, and poor sensitivity of the branched-chain DNA test. Molecular tests have also been developed to classify HCV into distinct genotypes; the clinical importance of HCV genotype determination remains a subject for future investigation.
1）检测丙型肝炎病毒抗体（抗-HCV）的血清学检测；2）检测、定量和/或鉴定感染患者体内HCV RNA基因组的分子检测。血清学检测已细分为抗-HCV的筛查检测，如酶免疫测定（EIA），以及补充检测，如重组免疫印迹测定（RIBA）。已开发出三代抗-HCV检测，每一代都提高了检测抗-HCV的灵敏度。补充抗-HCV检测旨在解决EIA的假阳性检测问题，适用于假阳性抗-HCV检测仍然是一个问题的低流行率环境。第三代抗-HCV检测（分别为EIA-3和RIBA-3）包含来自HCV核心、非结构3、非结构4和非结构5基因的抗原。通过聚合酶链反应（PCR）检测患者标本中的HCV RNA可提供活动性HCV感染的证据，对确诊和监测抗病毒治疗反应可能有用。目前最佳的HCV PCR检测灵敏度低于每毫升血浆或血清100拷贝的HCV RNA。进行HCV PCR检测的诊断实验室的标准化和能力验证仍是未来研究的一个重要问题。评估HCV RNA水平或病毒载量有两种主要技术。定量PCR是测定丙型肝炎病毒载量最灵敏的检测方法，而分支DNA检测似乎是最精确的方法。当前检测的主要局限性是基于PCR的检测动态范围不足、变异性高，以及分支DNA检测灵敏度低。分子检测也已用于将HCV分为不同的基因型；确定HCV基因型的临床重要性仍是未来研究的课题。
