From the Research
Epstein-Barr virus (EBV) IgG antibodies typically remain positive for life after initial infection. Once a person has been infected with EBV, these antibodies develop during the recovery phase and persist indefinitely, serving as a marker of past infection and immunity. This lifelong persistence makes EBV IgG testing useful for determining if someone has ever been infected with the virus, but not helpful for diagnosing recent or active infection. The persistence occurs because after the initial infection, EBV establishes latency in B lymphocytes, and the immune system maintains these antibodies as part of immunological memory.
To distinguish between past and recent infection, other serological markers such as EBV IgM antibodies or EBV viral capsid antigen (VCA) IgG avidity testing are more appropriate, as IgM antibodies typically appear early in infection and disappear within weeks to months, while low avidity IgG suggests recent infection 1. Understanding the permanence of EBV IgG positivity helps clinicians interpret test results correctly when evaluating patients with symptoms potentially related to EBV infection.
Some studies have shown that IgG antibodies to EBV can remain at a constant level for years after infection 2, and even decades later, these antibodies can still be detected 3. The most recent and highest quality study on this topic is from 2007, which found that EBV IgG antibodies can persist for life and are not indicative of recent infection 3.
Key points to consider when interpreting EBV IgG test results include:
- EBV IgG antibodies remain positive for life after initial infection
- IgM antibodies appear early in infection and disappear within weeks to months
- Low avidity IgG suggests recent infection
- EBV IgG testing is useful for determining past infection, but not recent or active infection
- Other serological markers, such as EBV IgM antibodies or VCA IgG avidity testing, are more appropriate for diagnosing recent infection.
In clinical practice, it is essential to consider the patient's symptoms, medical history, and other laboratory test results when interpreting EBV IgG test results 4. By understanding the permanence of EBV IgG positivity, clinicians can make more accurate diagnoses and develop effective treatment plans for patients with symptoms potentially related to EBV infection.