丙型肝炎核心抗原检测在丙型肝炎诊断中的意义

目的了解丙型肝炎核心抗原（HCV-cAg）检测方法的敏感性及特异性,确定具有临床意义的S/CO值,探讨其在丙型肝炎诊断中的意义。方法使用ELASA方法检测丙型肝炎核心抗原,RT-PCR检测HCV RNA定量,观察不同S/CO值所对应的HCV RNA定量之间的关系,以HCV RNA为诊断金标准,列四格表做诊断实验。结果 HCV-cAg抗原检测的敏感性为87.05%,特异性为76.67%,阳性预测值为96.53%,阴性预测值为44.23%。结论 （1）随着HCV-cAg的S/CO值逐渐增大,其与HCV RNA阳性符合率明显增高,随着HCV-cAg的S/CO值减小,其与HCV RNA阴性符合率明显增高;（2）S/CO值=2可以作为临床判断HCV感染病毒血症存在的一个标准;（3）本实验的敏感性和特异性较好,检测方法简单,可以作为丙型肝炎临床诊断的补充试验及筛查。

Detection of HCV core antigen and its diagnostic significance

Objective To compare the abilities of the hepatitis C virus（HCV） core antigen（cAg） test and the HCV RNA assay for confirming anti-HCV presence in order to determine the clinical utility of the HCV-cAg as an alternative or confirmatory diagnostic tool.Methods Serum samples collected from 158 patients diagnosed with HCV infection were subjected to the enzyme-linked immunosorbent assay-based HCV-cAg test.The optical density（OD） measured values were used to calculate the ratio of specimen absorbance to the cutoff value（S/CO）.Simultaneously,the serum samples were subjected to PCR-based nucleic acid amplification quantitative fluorescence detection of HCV RNA.Results None of the serum samples had a S/CO value 1 for the HCV-cAg test（100% negative）,but all of the samples had a S/CO value 5（100% positive）.The HCV-cAg test sensitivity was 87.05%,specificity was 76.67%,positive predictive value was 96.53%,and negative predictive value was 44.23%.As the S/CO value gradually increased,the significantly higher positive coincident rate of the HCV RNA test decreased.The HCV RNA negative coincident rate was significantly higher than that of the HCV-cAg test.HCV-cAg S/CO values between 1 and 2 corresponded to an HCV RNA values between 1.0×103 copies/ml and 1.0×104 copies/ml.The highest S/CO value obtained was 1.992.Conclusion The HCV-cAg test is comparable to the HCV RNA assay for diagnosing HCV infection.