Epstein-Barr Virus Antibodies Blood Test Kit

EBNA IgG antibodies target the Epstein-Barr Nuclear Antigen, a protein produced during the latent phase of EBV infection. These antibodies typically appear several weeks to months after the initial infection and remain detectable for life. What Positive Means: A positive EBNA IgG result indicates past EBV infection. These antibodies are not present during acute infection and typically appear 2–4 months after initial infection. Their presence confirms that you have been infected with EBV at some point and have developed long-term immunity. What Negative Means: A negative EBNA IgG result may indicate you have never been infected with EBV, or that you are in the early stages of acute infection before EBNA antibodies have developed. If VCA IgM is positive but EBNA IgG is negative, this pattern suggests recent primary infection. Clinical Significance: EBNA IgG is particularly useful for distinguishing between recent and past infection. It appears later than other EBV antibodies, so its absence in the presence of other positive markers suggests recent infection.

VCA IgM antibodies target the viral capsid antigen of EBV and are the first antibodies produced during acute infection. They typically appear when symptoms first develop and usually disappear within 4–6 weeks, though they may persist for up to 3 months in some individuals. What Positive Means: A positive VCA IgM result indicates current or recent EBV infection. This is the primary marker used to diagnose acute infectious mononucleosis (glandular fever). If you have symptoms of glandular fever, a positive VCA IgM strongly supports the diagnosis. What Negative Means: A negative VCA IgM result suggests you do not have acute EBV infection. However, if testing was performed very early after infection (within the first few days), antibodies may not yet have developed. A negative result in someone with typical symptoms may warrant repeat testing. Clinical Significance: VCA IgM is the most important marker for diagnosing acute glandular fever. Its presence, particularly when combined with negative EBNA IgG, provides strong evidence of primary EBV infection.

VCA IgG antibodies also target the viral capsid antigen but appear slightly later than IgM and persist for life. They typically appear 1–2 weeks after symptoms begin and remain detectable indefinitely, indicating past exposure to EBV. What Positive Means: A positive VCA IgG result indicates that you have been infected with EBV at some point. When combined with positive VCA IgM and negative EBNA IgG, it suggests recent or current infection. When VCA IgG is positive with negative VCA IgM and positive EBNA IgG, it indicates past infection. What Negative Means: A negative VCA IgG result suggests you have never been infected with EBV, or that you are in the very early stages of infection before IgG has developed. Most adults (90–95%) have positive VCA IgG, indicating past EBV exposure. Clinical Significance: VCA IgG confirms EBV exposure has occurred. Combined with other markers, it helps determine the timing of infection and distinguishes between primary infection, past infection, and reactivation.