Kalita Deepjyoti, Deka Sangeeta, Chamuah Kailash, Ahmed Giasuddin
Dept. of Microbiology, All India Institute of Medical Sciences, Rishikesh, Virbhadra Road, Rishikesh 249203, Uttarakhand, India.
State Level Viral Research and Diagnostic Laboratory (VRDL), Gauhati Medical College & Hospital, Guwahati, PO: Indrapur, 781005, Guwahati, India.
J Clin Exp Hepatol. 2022 Mar-Apr;12(2):475-482. doi: 10.1016/j.jceh.2021.05.011. Epub 2021 Jun 16.
Subjects undergoing hemodialysis have enhanced vulnerability to hepatitis C virus (HCV) infection due to invasive procedures and poor infection control practices. Early detection and treatment are essential to prevent cross-infection and mortality/morbidity. However, common use anti-HCV antibody tests lack the necessary accuracy, and alternative tests (e.g. core antigen detection kits) which are available need to be examined as a viable alternative.
A total of 270 continuous serum samples were collected from patients undergoing dialysis within 15 months of study period. Sequentially, multiple tests were performed - immunochromatography-based rapid test, third-generation ELISA i.e. (anti-HCV antibody detection), fourth-generation ELISA (HCV antigen-antibody combined detection assay), and HCV RNA quantitative real time polymerase chain reaction (qPCR) assay. Diagnostic parameters of serological kits were compared in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and so on. Statistical Package for the Social Sciences was used.
HCV-combined core antigen-antibody assays performed better than other serological assays in reference to the gold standard HCV RNA. This fourth-generation assay yielded a Kappa value of 0.947 compared with the value of 0.747 and 0.619 for anti-HCV ELISA and rapid detection test. Other parameters such as sensitivity, specificity, PPV, NPV, and so on were also better for fourth-generation ELISA compared with third-generation ELISA and other serological assays. HCV RNA was negative in 7.3% of anti-HCV-positive patients and was detected in 11.4% of anti-HCV ELISA-negative patients. In about 1.6% of HCV RNA-positive cases, fourth-generation ELISA was negative and had low HCV viral load (650 IU/ml and below). Fourth generation ELISA detected additional 7.4% HCV positive cases (compared to third generation kits) and upon cost effective analyis, additional cost to be bear for the better detection (by fourth generation kit) was found to be only INR 27 per 1% increased case detection.
In resource scant setup, screening and follow-up of patients undergoing hemodialysis can be performed by fourth-generation HCV ELISA (antigen-antibody combined assay) instead of the current practice of anti-HCV antibody ELISA. Better yield in detection rate will compensate for slight addition to costs.
由于侵入性操作和感染控制措施不力，接受血液透析的患者感染丙型肝炎病毒（HCV）的风险增加。早期检测和治疗对于预防交叉感染及死亡率/发病率至关重要。然而，常用的抗HCV抗体检测缺乏必要的准确性，需要对现有的替代检测方法（如核心抗原检测试剂盒）作为可行的替代方法进行研究。
在研究期间的15个月内，从接受透析的患者中总共收集了270份连续血清样本。依次进行多项检测——基于免疫层析的快速检测、第三代酶联免疫吸附测定法（即抗HCV抗体检测）、第四代酶联免疫吸附测定法（HCV抗原-抗体联合检测测定法）以及HCV RNA定量实时聚合酶链反应（qPCR）测定法。从灵敏度、特异性、阳性预测值（PPV）、阴性预测值（NPV）、准确性等方面比较了血清学试剂盒的诊断参数。使用社会科学统计软件包进行分析。
与金标准HCV RNA相比，HCV核心抗原-抗体联合检测法比其他血清学检测法表现更好。与抗HCV酶联免疫吸附测定法和快速检测法的Kappa值分别为0.747和0.619相比，这种第四代检测法的Kappa值为0.947。与第三代酶联免疫吸附测定法和其他血清学检测法相比，第四代酶联免疫吸附测定法的其他参数，如灵敏度、特异性、PPV、NPV等也更好。在抗HCV阳性患者中，7.3%的患者HCV RNA为阴性，在抗HCV酶联免疫吸附测定法阴性的患者中，11.4%检测到HCV RNA。在约1.6%的HCV RNA阳性病例中，第四代酶联免疫吸附测定法为阴性，且HCV病毒载量较低（650 IU/ml及以下）。第四代酶联免疫吸附测定法检测出额外7.4%的HCV阳性病例（与第三代试剂盒相比），经成本效益分析，为更好地检测（通过第四代试剂盒）每增加1%的病例检测需额外承担的成本仅为27印度卢比。
在资源匮乏的情况下，接受血液透析患者的筛查和随访可以通过第四代HCV酶联免疫吸附测定法（抗原-抗体联合检测法）进行，而不是目前使用的抗HCV抗体酶联免疫吸附测定法。检测率的提高将弥补成本的轻微增加。
