Department of Internal Medicine, Kangdong Sacred Heart Hospital of Hallym University Medical Center, Seoul, Korea.
Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Korea.
Korean J Intern Med. 2023 May;38(3):362-371. doi: 10.3904/kjim.2022.350. Epub 2023 Apr 11.
BACKGROUND/AIMS: Although anti-hepatitis C virus (HCV) assay is widely used to screen for HCV infection, it has a high false-positive (FP) rate in low-risk populations. We investigated the accuracy of anti-HCV signal-to-cutoff (S/CO) ratio to distinguish true-positive (TP) from FP HCV infection.
We retrospectively analyzed 77,571 patients with anti-HCV results. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of anti-HCV S/CO ratio in anti-HCV positive patients.
Overall, 1,126 patients tested anti-HCV positive; 34.7% of patients were FP based on HCV RNA and/or recombinant immunoblot assay (RIBA) results. The age and sex-adjusted anti-HCV prevalence was 1.22%. We identified significant differences in serum aspartate transaminase and alanine transaminase levels, anti-HCV S/CO ratio, and RIBA results between groups (viremia vs. non-viremia, TP vs. FP). Using ROC curves, the optimal cutoff values of anti-HCV S/CO ratio for HCV viremia and TP were 8 and 5, respectively. The area under the ROC curve, sensitivity, specificity, positive and negative predictive values were 0.970 (95% CI, 0.959-0.982, p < 0.001), 99.7%, 87.5%, 87.4%, and 99.7%, respectively, for predicting HCV viremia at an anti-HCV S/CO ratio of 8 and 0.987 (95% CI, 0.980-0.994, p < 0.001), 95.3%, 94.7%, 97.1%, and 91.4%, respectively, for TP HCV infection at an anti-HCV S/CO ratio of 5. No patients with HCV viremia had an anti-HCV S/CO ratio below 5.
The anti-HCV S/CO ratio is highly accurate for discriminating TP from FP HCV infection and should be considered when diagnosing HCV infections.
背景/目的：尽管抗丙型肝炎病毒（HCV）检测已广泛用于筛查 HCV 感染，但在低危人群中其假阳性（FP）率较高。本研究旨在探讨抗-HCV 信号与对照（S/CO）比值鉴别真阳性（TP）与 FP HCV 感染的准确性。
我们回顾性分析了 77571 例抗-HCV 检测结果。通过受试者工作特征（ROC）曲线分析评估抗-HCV S/CO 比值在抗-HCV 阳性患者中的诊断准确性。
共有 1126 例患者抗-HCV 检测阳性，其中 34.7%的患者 HCV RNA 和/或重组免疫印迹分析（RIBA）结果为 FP。年龄和性别校正后的抗-HCV 阳性率为 1.22%。我们发现，在病毒血症与非病毒血症组、TP 与 FP 组间，血清天门冬氨酸转氨酶和丙氨酸转氨酶水平、抗-HCV S/CO 比值和 RIBA 结果均存在显著差异。ROC 曲线分析显示，抗-HCV S/CO 比值预测 HCV 病毒血症和 TP 的最佳截断值分别为 8 和 5。其 ROC 曲线下面积、敏感性、特异性、阳性预测值和阴性预测值分别为 0.970（95%CI：0.959-0.982，p < 0.001）、99.7%、87.5%、87.4%和 99.7%，用于预测抗-HCV S/CO 比值为 8 时的 HCV 病毒血症，分别为 0.987（95%CI：0.980-0.994，p < 0.001）、95.3%、94.7%、97.1%和 91.4%，用于预测抗-HCV S/CO 比值为 5 时的 TP HCV 感染。无病毒血症患者的抗-HCV S/CO 比值均<5。
抗-HCV S/CO 比值在鉴别 TP 与 FP HCV 感染方面具有较高的准确性，在诊断 HCV 感染时应加以考虑。
