EBV Nuclear Antigen (EBNA) IgG
Immunity & allergy markersWhat the test generally measures, and what to ask about it.
Longetic keeps every lab and record you’ve had organized and easy to find, so your own EBV Nuclear Antigen (EBNA) IgG values sit together on one chart and you walk into your next appointment prepared.
What is EBV Nuclear Antigen (EBNA) IgG?
Measures IgG antibodies against the Epstein-Barr nuclear antigen (EBNA), which typically appear later and indicate past infection.
This test measures IgG antibodies against the Epstein-Barr virus (EBV) nuclear antigen (EBNA), which generally develop several weeks to a few months after infection and then persist for life. Because EBNA IgG appears later than VCA antibodies, it relates to the immune system's longer-term memory response and is a key marker for distinguishing past infection from a recent or current one. Clinicians commonly order it alongside VCA IgG and IgM when the timing of EBV exposure needs to be clarified, since a positive VCA IgG with a negative EBNA IgG generally points toward more recent infection, while a positive result for both generally reflects infection from the more distant past.
Tests often checked alongside this
- EBV VCA IgG and IgM — used together to help time the original infection
- EBV Early Antigen D (EA-D) IgG — another marker considered for timing and activity
- Complete Blood Count (CBC) — general immune-related marker sometimes checked alongside
How this can show up in how you look and feel
- May be associated with a history of past mononucleosis-type symptoms, such as fatigue or sore throat
- May be associated with no recollection of symptoms, since many EBV infections go unnoticed
What can affect this marker
- Time elapsed since original infection
- Age, since EBNA IgG typically takes longer to develop than VCA antibodies
- Immune status
- Lab-to-lab variability in assay methods
What to track over time
- How EBNA IgG relates to VCA IgG and IgM results to clarify infection timing
- Whether any current symptoms are consistent with past versus recent infection
- General stability of this marker over time, since it typically remains positive for life once developed
What to ask your doctor
- Does this result confirm my EBV infection was in the past?
- How does this fit with my VCA IgG and IgM results?
- Could my current symptoms be related to something other than EBV?
- Is there any reason to repeat or expand EBV testing?
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References
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