Epstein-Barr Virus (EBV) Antibodies to Viral Capsid Antigen (VCA), IgM

The Epstein-Barr Virus (EBV) Antibodies to Viral Capsid Antigen (VCA), IgM test—also referred to as EBV VCA IgM or anti‑VCA IgM—is used to establish acute or recent primary EBV infection consistent with infectious mononucleosis. It also assists in distinguishing EBV from other causes of mononucleosis‑like illness when symptoms overlap.

Epstein–Barr virus (human herpesvirus 4) primarily infects B lymphocytes and is linked to infectious mononucleosis and several EBV‑associated conditions, including nasopharyngeal carcinoma, Burkitt lymphoma, Hodgkin disease, oral hairy leukoplakia, and B‑cell lymphomas. The virus is widespread globally and is transmitted through saliva, with many initial infections occurring in childhood or adolescence. Following entry through the oropharyngeal epithelium, EBV disseminates hematogenously and drives B‑cell proliferation, producing tonsillar and nodal enlargement and splenomegaly; immunocompetent individuals typically control the infection and symptoms abate. EBV then persists in a latent state within a subset of B cells and can contribute to lymphoproliferative disease when cellular immunity is compromised (eg, HIV infection or iatrogenic immunosuppression).