22576 EBV Viral Capsid Antigen IgM and IgG Antibodies

EBV, VCA, Epstein-Barr Virus, Mono​

This test detects IgM and IgG class antibodies to Epstein Barr virus (EBV) viral capsid antigen (VCA).
IgM class antibody to EBV VCA develops early in the course of acute EBV infection (clinically described as infectious mononucleosis, IM). Typically, anti-VCA IgM is rapidly replaced by anti-VCA IgG during the late acute phase, although the IgM antibody may persist; it may also reappear in EBV reactivation. Detectable levels of anti-VCA IgG will then persist indefinitely throughout life.
The detection of anti-VCA antibodies is a useful adjunct for patients presenting with IM-like disease in which the Paul-Bunnell heterophile spot antibody test (e.g. Monospot) is negative. The Monospot test has an overall sensitivity of approximately 90% in the detection of IM, although sensitivity increases with age (i.e. the Monospot test is least sensitive in young children). See Infectious Mononucleosis, (test code IM) for information on the Monospot test.
The EBV Comprehensive Antibody Panel (EBVCOMP) should be considered in place of this test for the serodiagnosis of EBV-related chronic and reactivation diseases. ​

Gross hemolysis

The presence of anti-VCA IgM, with or without anti-VCA IgG, provides evidence of acute EBV infection in patients clinically suspected of IM. The presence of anti-VCA IgG alone in patients who appear to be recovering from IM gives evidence of a recent acute EBV infection. In asymptomatic individuals, the presence of anti-VCA IgM & IgG indicates silent acute EBV infection, while the presence of anti-VCA IgG alone is evidence of past infection. Note that EBV, like all herpesviruses, is not cleared after acute infection, but latently persists, primarily in B-lymphocytes and nasopharyngeal epithelial cells. Asymptomatic individuals with anti-VCA IgG may therefore be considered to be latently infected with EBV.​