Hepatitis C virus (HCV) core antibody (anti-HCV core antibody) is an antibody produced by the host immune system in response to the HCV core protein, a highly conserved structural protein that forms the viral nucleocapsid. The HCV core protein plays important roles in viral RNA packaging, capsid assembly, and interactions with host cellular pathways.

Anti-HCV core antibodies are important markers of exposure to HCV infection. They generally develop during the course of infection and may persist after viral clearance, either spontaneously or following successful antiviral treatment. Therefore, the presence of anti-HCV antibodies indicates previous or current exposure to HCV but does not, by itself, distinguish between active and resolved infection. Detection of HCV RNA is required to confirm ongoing viral replication and active infection.

Because of their diagnostic value, anti-HCV antibodies are widely used in screening assays for HCV infection. In addition to their clinical applications, antibodies targeting the HCV core protein are valuable research tools for studying viral biology, antigen detection, and the development of diagnostic assays.