Utility of enzyme-linked immunosorbent assays to test core antigen in the diagnosis and antiviral therapy management of hepatitis C virus infections

Performance of HCV Antigen Testing for the Diagnosis and Monitoring of Antiviral Treatment: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Active hepatitis C virus (HCV) infection is based on the detection of HCV RNA that it is effective but presents high cost and the need to hire trained personnel. This systematic review and meta-analysis is aimed at evaluating the diagnostic accuracy of HCV Ag testing to identify HCV cases and to monitor antiviral treatment including DAA treatment.

METHODS

The studies were identified through a search in PubMed, Lilacs, and Scopus from 1990 through March 31, 2020. Cohort, cross-sectional, and randomized controlled trials were included. Two independent reviewers extracted data and assessed quality using an adapted Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Our primary outcome was to determine the accuracy of HCV Ag detection for the diagnosis, which we estimated using random-effects meta-analysis.

RESULTS

Of 3,062 articles identified, 54 met our eligibility criteria. The studies described cohorts from 20 countries, including 14,286 individuals with chronic HCV individuals. Studies for ECLIA technology demonstrated highest quality compared to studies that used ELISA. The pooled sensitivity and specificity (95% CI) for HCV Ag detection of active HCV infection were 98.82% (95%CI = 98.04%; 99.30%) and 98.95% (95%CI = 97.84%; 99.49%), respectively. High concordance was found between HCV Ag testing and HCV RNA detection 89.7% and 95% to evaluate antiviral treatment.

CONCLUSIONS

According to our findings, HCV Ag testing could be useful to identify HCV active cases in low-resource areas. For antiviral treatment, HCV Ag testing will be useful at the end of treatment.

Hepatitis C core antigen: a simple predictive marker for treatment response to the new direct-acting antiviral drugs in chronic HCV Egyptian patients

Background

Successful eradication of hepatitis C virus (HCV) has great impact on the prognosis of HCV-related complications and the associated mortality. The development of the new direct-acting antiviral drugs (DAAs) has revolutionized the treatment of HCV infection. HCV core antigen (HCVcAg) is a recently developed marker that displayed a good correlation with HCV RNA assays. Our main objectives were to correlate between serum levels of HCVcAg and HCV RNA loads in chronic HCV patients as well as to explore the potential value of HCVcAg assay in predicting treatment response to the new DAAs. The study enrolled a total of 280 chronic HCV-infected patients scheduled to start the new regimen for treatment of chronic HCV by all-oral, interferon-free DAAs. According to the viral load, the studied individuals were arranged into three groups corresponding to mild, moderate, and sever viremia. Serum level of HCVcAg was determined by ELISA technique and HCV RNA viral loads were quantified using the real-time PCR system. The assays were performed three times for all participants: prior to initiation of treatment, at the end of treatment (week 12), and 3 months post-treatment cessation (week 24).

Results

A statistically significant difference between HCV RNA and HCVcAg baseline levels among different viremia groups was detected (P < 0.001). There was a significant positive correlation between HCV RNA and HCVcAg baseline values among all the studied cases (P < 0.05) with a correlation coefficient of 0.752, 0.976, and 1.00 respectively for mild, moderate, and severe viremia groups. 92.9% (260/280) of the studied patients achieved sustained virologic response, 3.6% (10/280) were non-responders, and 3.6% (10/280) had recurrent viremia/relapse as regards RT-PCR results.

Conclusion

HCVcAg is a promising alternative to HCV RNA assay. The ELISAs for HCVcAg proved excellent correlations with HCV RNA levels. Moreover, HCVcAg can be introduced as a simple and highly specific tool for monitoring the new DAA regimens particularly in low-resource settings.