Source Division of Infectious Diseases, University of Toronto, University Health Network, Transplant Infectious Diseases, Toronto General Hospital, Toronto, ON, Canada; Urology and Nephrology Research Center (UNRC), Shahid Beheshti University of Medical Sciences, Tehran, IR, Iran. seyed.hosseini@uhn.on.ca.

Chronic hepatitis C virus (HCV) infection which is often a silent disease has resulted in a global epidemic. The diagnosis of hepatitis C virus often requires confirmation with molecular techniques such as the polymerase chain reaction for detection of HCV RNA. Following laboratory confirmation of the diagnosis, molecular techniques are routinely used to monitor HCV RNA levels, particularly in those undergoing treatment. Unfortunately, molecular tests are relatively expensive and their cost may be prohibitive in the developing world. Several studies have investigated the applicability of the hepatitis C core Ag (HCVcAg), as a substitute for measuring HCV RNA levels. In this review, we provide an overview of the major findings of these studies focused on the utility of measuring HCVcAg antigen levels in the clinical setting. Overall, measuring HCVcAg levels is associated with several advantages and disadvantages. It may be useful in different clinical settings for monitoring HCV patients after obtaining an initial baseline HCV RNA result.