Background Diagnosis of chronic hepatitis C virus (HCV) infection requires both a positive HCV antibody screen and confirmatory nucleic acid testing (NAT). Testing for hepatitis C virus core antigen (HCVcAg) is a potential alternative to NAT. Purpose To evaluate the accuracy of diagnosis of active HCV infection among adults and children for 5 HCVcAg tests compared with NAT. Data sources EMBASE, PubMed, Web of Science, Scopus, and Cochrane Database of Systematic Reviews from 1990 through 31 March 2016. Study selection Case-control, cross-sectional, cohort, or randomized trials that compared any of 5 HCVcAg tests with an NAT reference standard. Data extraction 2 independent reviewers extracted data and assessed quality using an adapted QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool. Data synthesis 44 studies evaluated 5 index tests. Studies for the Abbott ARCHITECT HCV Ag assay had the highest quality, whereas those for the Ortho HCV Ag enzyme-linked immunosorbent assay (ELISA) had the lowest quality. From bivariate analyses, the sensitivity and specificity of the assays were as follows: Abbott ARCHITECT, 93.4% (95% CI, 90.1% to 96.4%) and 98.8% (CI, 97.4% to 99.5%); Ortho ELISA, 93.2% (CI, 81.6% to 97.7%) and 99.2% (CI, 87.9% to 100%); and Hunan Jynda Bioengineering Group HCV Ag ELISA, 59.5% (CI, 46.0% to 71.7%) and 82.9% (CI, 58.6% to 94.3%). Insufficient data were available for a meta-analysis about the Fujirebio Lumipulse Ortho HCV Ag and Eiken Lumispot HCV Ag assays. In 3 quantitative studies using Abbott ARCHITECT, HCVcAg correlated closely with HCV RNA levels greater than 3000 IU/mL. Limitations Insufficient data were available on covariates, such as HIV or hepatitis B virus status, for subgroup analyses. Few studies reported genotypes of isolates, and data for genotypes 4, 5, and 6 were scant. Most studies were conducted in high-resource settings and reference laboratories. Conclusion The HCVcAg assays with signal amplification have high sensitivity, high specificity, and good correlation with HCV RNA levels greater than 3000 IU/mL and have the potential to replace NAT in settings with high HCV prevalence. Primary funding source National Institutes of Health.

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Hepatitis C Core Antigen Testing for Diagnosis of Hepatitis C Virus Infection: A Systematic Review and Meta-analysis

Diagnosis of chronic hepatitis C virus (HCV) infection usually requires both a positive HCV antibody screen and confirmatory nucleic acid testing (NAT). This systematic review of 44 studies evaluat...

Hepatitis C Core Antigen Testing for Diagnosis of Hepatitis C Virus Infection

Who to test and how to test for chronic hepatitis C infection – 2016 WHO testing guidance for low- and middle-income countries

Diagnosis and monitoring of hepatitis C virus (HCV) infection relies mainly on the detection of HCV antibodies and HCV RNA. HCV antibody test has a longer window period and is not applicable in the immunosuppressed population. Although HCV RNA test reduces the window period, it is still not widely recommended because of its high cost and requirement of specific equipment. HCV core antigen is another direct virological marker which has been investigated in recent years. HCV core antigen assay is as simple as the HCV antibodies assay and can detect HCV infection only 1 day delay compared to the HCV RNA assay. In order to evaluate the application of HCV core antigen test in HCV diagnosis and management, we performed this meta-analysis. Twenty five articles were finally included in meta-analysis. All statistical analyses were performed with MetaDisc 1.4 and Stata 11.0. The pooled sensitivity of HCV core antigen assay was 0.84 (95 % CI, 0.83-0.85), and the pooled specificity was 0.98 (95 % CI, 0.97-0.98). HCV core antigen assays may not displace HCV RNA assays to be a definitive diagnosis of HCV infection until now. Considering the higher sensitivity (0.926) and specificity (0.991) of subgroup, HCV-cAg detection is a promising method as a confirmatory test for HCV antibody positive, therapy-naive individuals. Explored by meta-regression and subgroup analysis, possible sources of heterogeneity of specificity was found, while the heterogeneity of sensitivity was still significant.

Core antigen tests for hepatitis C virus: a meta-analysis

Diagnosis and monitoring of hepatitis C virus (HCV) infection relies mainly on the detection of HCV antibodies and HCV RNA HCV antibody test has a longer window period and is not applicable in the immunosup- pressed population Although HCV RNA test reduces the window period, it is still not widely recommended because of its high cost and requirement of specific equipment HCV core antigen is another direct virological marker which has been investigated in recent years HCV core antigen assay is as simple as the HCV antibodies assay and can detect HCV infection only 1 day delay compared to the HCV RNA assay In order to evaluate the application of HCV core antigen test in HCV diagnosis and management, we per- formed this meta-analysis Twenty five articles were finally included in meta-analysis All statistical analyses were per- formed with MetaDisc 14 and Stata 110 The pooled sen- sitivity of HCV core antigen assay was 084 (95 % CI, 083-085), and the pooled specificity was 098 (95 % CI, 097-098) HCV core antigen assays may not displace HCV RNA assays to be a definitive diagnosis of HCV infection until now Considering the higher sensitivity (0926) and specificity (0991) of subgroup, HCV-cAg detection is a promising method as a confirmatory test for HCV antibody positive, therapy-naive individuals Explored by meta- regression and subgroup analysis, possible sources of het- erogeneity of specificity was found, while the heterogeneity of sensitivity was still significant

[Objective]To investigate the significance of serum total HCV core antigen(HCV-cAg) in the HCV infection and treatment.[Methods]One hundred and seventy-three serum specimens of HCV infection patients were examined for HCV cAg and anti-HCV antibody with ELISA,for HCV RNA with real-time RT-PCR.[Results]In 173 anti-HCV positive specimens,the positive rate of HCV RNA was 49.7%(86/173) and the positive rate of HCV-cAg was 36.4%(63/173).The positive rate of HCV RNA was higher than that of HCV-cAg(P0.05).In 86 HCV RNA positive specimens,the positive rate of HCV-cAg was 69.8%(60/86),the negative rate was 30.2%(26/86).The control was negative.[Conclusions]In laboratory where it is impossible for HCV RNA measurement by using RT-PCR,HCV-cAg assay in serum will be very useful for the clinical diagnosis of hepatitis C and the detection of HCV.

Zhang Tao

Papers

Clinical significance of testing hepatitis C virus core antigen.