HCV core antigen is an alternative marker to HCV RNA for evaluating active HCV infection: implications for improved diagnostic option in an era of affordable DAAs

Rujipat Wasitthankasem; Preeyaporn Vichaiwattana; Chompoonut Auphimai; Nipaporn Siripon; Sirapa Klinfueng; Pisit Tangkijvanich; Sompong Vongpunsawad; Yong Poovorawan

doi:10.7717/peerj.4008

HCV core antigen is an alternative marker to HCV RNA for evaluating active HCV infection: implications for improved diagnostic option in an era of affordable DAAs

PeerJ. 2017 Nov 6:5:e4008. doi: 10.7717/peerj.4008. eCollection 2017.

Authors

Rujipat Wasitthankasem¹, Preeyaporn Vichaiwattana¹, Chompoonut Auphimai¹, Nipaporn Siripon¹, Sirapa Klinfueng¹, Pisit Tangkijvanich², Sompong Vongpunsawad¹, Yong Poovorawan¹

Affiliations

¹ Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
² Research Unit of Hepatitis and Liver Cancer, Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Thailand.

Abstract

The core antigen of the hepatitis C virus (HCV Ag) presents an alternative marker to HCV RNA when screening patients for HCV viremia. This study sought to evaluate the utility of HCV Ag as a marker to assess active HCV infection in individuals residing in an HCV-endemic area. From 298 HCV-seropositive individuals evaluated for the presence of anti-HCV antibody, HCV Ag and HCV RNA, anti-HCV antibody was detected in 252 individuals (signal-to-cutoff ratios ≥5), HCV RNA was detected in 222 individuals (88%), and HCV Ag was reactive (≥3 fmol/L) in 220 individuals (87%). HCV genotype 1, 3, and 6 were identified. HCV Ag significantly correlated with HCV RNA irrespective of HCV genotype and/or HBV co-infection (log HCV RNA = 2.67 + 0.95 [log HCV Ag], R² = 0.890, p < 0.001). To predict HCV viremia (HCV Ag ≥ 3 fmol/L), the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 99%, 99%, 100%, 100% and 97%, respectively. We concluded that HCV Ag was a good surrogate marker for HCV RNA and could be used to diagnose active HCV infection in a resource-limited setting. As a result, a cost-effective strategy for screening and identifying active HCV carriers using HCV Ag detection would enable more patients access to efficacious and increasingly affordable direct-acting antivirals (DAAs) for the treatment of HCV infection.

Keywords: Active HCV infection; HCV Ag; HCV RNA; Hepatitis C virus.

Grants and funding

This work was supported by the Research Chair Grant from the National Science and Technology Development Agency (P-15-5004), Chulalongkorn University Centenary Academic Development Project (CU56-HR01); the Senior Research Scholar, Thailand Research Fund (RTA5980008); Ratchadaphiseksomphot Endowment Fund for Postdoctoral Fellowship to Rujipat Wasitthankasem; the Center of Excellence in Clinical Virology, Chulalongkorn University (GCE58- 014-30-004); and King Chulalongkorn Memorial Hospital. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.