当前诊断丙型肝炎病毒（HCV）感染的标准方法需要两个连续的步骤：用于筛选的HCV抗体测试，随后进行HCV RNA RT-PCR测试来验证病毒血症性HCV（viremic HCV, V-HCV）感染（编者注：即导致病毒血症的HCV感染）。这使得它未最优化、成本高、不方便、耗时和不能够在全球广泛使用或负担得起。

　　HCV核心抗原（HCVcAg）测试有潜力提供一步法诊断HCV感染。然而，它的灵敏度和特异性较低限制了它的临床应用。

　　在一项新的研究中，来自美国加州大学欧文分校的研究人员开发出一种新的HCV抗原酶免疫测定法（HCV-Ags EIA），并利用365种血清样品（其中，176种未发生V-HCV感染，189种发生V-HCV感染）评估了这种一步法诊断V-HCV感染的灵敏度、特异性和实用性。相关研究结果于2016年6月6日在线发表在Hepatology期刊上，论文标题为“A Highly Specific and Sensitive Hepatitis C Virus Antigens Enzyme Immunoassay for One-step Diagnosis of Viremic HCV Infection”。

　　首先，研究人员证实在HCV感染期间，除了HCV核心抗原之外，还存在HCV NS3、NS4b和NS5a蛋白。基于此，他们开发出这种新的同时检测这四种HCV蛋白的HCV-Ags EIA方法。

　　这项研究首次证实血清样品变性导致释放出的HCV抗原以HCV免疫复合物的形式存在，从而降低测试特异性，因此应当不能够用于任何HCV抗原测试，包括所有当前的HCV核心抗原测试。

　　另一方面，与血清HCV抗体测试和HCV RNA RT-PCR测试的结果相比较，利用未变性的血清样品，这种HCV-Ags EIA测试结果的特异性为99%，灵敏度为100%。

　　利用未变性的进行过稀释的血清样品进行测试，这种HCV-Ags EIA方法的最低检测限相当于大约150～250 IU/mL的血清HCV RNA水平。

　　研究人员开发出的这种HCV-Ags EIA方法是高度特异性的和高度灵敏的。利用未变性的血清样品，这种HCV-Ags EIA方法能够可靠地区分V-HCV感染和已得到控制的HCV感染，而且是一步法实现对V-HCV感染的筛选和诊断。

　　论文作者写道，“慢性HCV感染影响全世界大约1.7亿人，并且与发展为肝硬化和肝细胞癌的风险相关联。尽管卫生专业实践指导方针主张对HCV感染进行筛选，但是最近的研究表明在HCV感染的筛选和诊断方面还存在重大的缺口。”

　　A Highly Specific and Sensitive Hepatitis C Virus Antigens Enzyme Immunoassay for One-step Diagnosis of Viremic HCV Infection

　　doi:10.1002/hep.28663

　　Ke-Qin Hu,Wei Cui

　　The current standard in diagnosing HCV infection requires 2 sequential steps: anti-HCV test to screen, followed by HCV RNA RT-PCR to confirm viremic HCV (V-HCV) infection. HCV core antigen (HCVcAg) tests provided potential for possible one-step diagnosis. However, low sensitivity and specificity limit their clinical utility. The present study developed a novel HCV antigens enzyme immunoassay (HCV-Ags EIA) and assessed its sensitivity, specificity, and utility for one-step diagnosis of V-HCV infection using 365 serum specimens, including 176 without, and 189 with V-HCV infection. First, we confirmed presence of HCV non-structural protein 3 (NS3), NS4b, and NS5a proteins besides HCVcAg during HCV infection, and developed a novel HCV-Ags EIA via simultaneous detection of all these 4 HCV proteins. For the first time, the presented study demonstrated that serum sample denaturation decreases the test specificity due to release of HCV-Ags sequestered in HCV-immune complexes, and should not be used in any HCV-Ags, including all the current HCVcAg assays. On the other hand, using sample non-denaturation, the HCV-Ags EIA results showed 99% specificity and 100% sensitivity compared to serum anti-HCV and HCV RNA RT-PCR results. Using serum sample dilution, and non-denaturation, the lowest limits of detection of the HCV-Ags EIA were equivalent to serum HCV RNA levels of approximate 150-250 IU/mL. CONCLUSIONS: The highly specific and sensitive HCV-Ags EIA developed in the present study has the lowest limit of detection equivalent to serum HCV RNA levels of 150-250 IU/mL. Using non-denaturation of serum samples, our HCV-Ags EIA reliably differentiated V-HCV infection from resolved HCV infection, accomplishes screening and diagnosis of V-HCV infection in one step. This article is protected by copyright. All rights reserved.