Hepatitis C core antigen: diagnosis and monitoring of patients infected with Hepatitis C virus.

Abstract

INTRODUCTION\nNew efficient strategies are needed for assessing active hepatitis C virus (HCV) infection. We aim to evaluate the capacity the core antigen as a marker of active HCV infection in new diagnosed patients, treatment monitoring and detection of therapeutic failure.\n\n\nMATERIALS AND METHODS\nA prospective study was carried out in a regional referenced hospital in Spain. HCV core antigen (HCV-cAg) and viral load (RNA-HCV) were tested in plasma or serum samples from three patient groups: new diagnosis, monitoring treatment and therapeutic failure. The monitoring treatment group was tested at the beginning of the treatment, four weeks post-initiation, at the end, and 12 weeks post-treatment finalization. For HCV-cAg testing the Architect core antigen assay® was performed and viral load was quantified with the Cobas 6800 system.\n\n\nRESULTS\nWe analyzed 303 samples from 124 patients. Excellent correlation (R2\u2009=\u20090.932) between HCV-Ag and HCV-RNA was seen. The optimal cut-off value was 3\u2009fmol/L in the ROC analysis and the area under the curve was 0.987 (0.972-1.000). HCV-cAg sensitivity and specificity were 97% and 95%, respectively. Most diverging results were observed in the treatment follow-up group.\n\n\nCONCLUSIONS\nThe HCV-cAg demonstrated good sensitivity and specificity as a marker for active HCV infection, new diagnosis, detection of antiviral therapeutic failure and treatment monitoring.