The potential role of HCV core antigen testing in diagnosing HCV infection.

The potential uses of serological tests that detect HCV core antigens in biological fluids are highlighted. The most common serological tests utilized to detect exposure to HCV rely on the detection of antibodies to HCV. However, these tests cannot distinguish between individuals who have resolved their infection and those who remain actively infected with HCV. By contrast, the HCV core antigen test detects circulating HCV core antigen and identifies individuals who are actively infected with HCV. There is increasing interest in using the HCV core antigen test as a reflex test for seropositive individuals to identify individuals who are actively infected with HCV. In addition, the HCV core antigen test can be utilized to detect the early phase of HCV infection prior to the development of antibodies, both in the blood bank setting and in the diagnostic laboratory. Lastly, quantitative versions of the HCV core antigen test can be used to monitor the effectiveness of antiviral therapy.