The EBV (Epstein Barr) Nuclear Antigen Antibodies, IgG test looks for a type of antibody which the body typically develops in response to Epstein-Barr Virus.
EBNA antibodies usually appear 2-4 months after infection and persist for the life of the person. This test is usually performed to establish a past infection with EBV.
Epstein-Barr Virus is one of the most common viruses with as many as 95% of the people in the US having been exposed by the age of 40. In many people the virus causes no symptoms. Those infected during adolescence or young adulthood may develop Infectious Mononucleosis (Mono). Common symptoms of Mono include fatigue, fever, sore throat, swollen lymph glands, and sometimes an enlarged spleen or liver.
Additional complications affecting the heart or nervous system may occur but are rare. Symptoms of Mono typically clear up after a couple months but EBV will remain dormant in the body for the rest of a person’s life. Periodic reactivation of the virus may occur but usually does not cause symptoms or illness. EBV is normally spread through contact with an infected person’s saliva. Some people remain capable of transmitting the virus throughout their lives.
The presence of antibodies to EBNA means that the infection occurred in the past. Antibodies to EBNA develop six to eight weeks after the time of infection and are present for life.
The test has 3 components:
– viral capsid antigen (VCA) IgG,
– VCA IgM,
– and Epstein-Barr nuclear antigen (EBNA).
Presence of VCA IgM antibodies indicates recent primary infection with Epstein-Barr virus (EBV). The presence of VCA IgG antibodies indicates infection sometime in the past. Antibodies to EBNA develop 6 to 8 weeks after primary infection and are detectable for life. Over 90% of the normal adult population has IgG class antibodies to VCA and EBNA. Few patients who have been infected with EBV will fail to develop antibodies to the EBNA (approximately 5%-10%).
Higher levels:
The presence of antibodies to EBNA means that the infection occurred in the past. Antibodies to EBNA develop six to eight weeks after the time of infection and are present for life.
Possible Results | |||
VCA IgG | VCA IgM | EBNA IgG | Interpretation |
+ | – | + | Past infection |
+ | + | + | Past infection |
Lower levels:
Possible Results | |||
VCA IgG | VCA IgM | EBNA IgG | Interpretation |
– | – | – | No previous exposure |
+ | + | – | Recent infection |
+ | – | – | See note* |
*Results indicate infection with EBV at some time (VCA IgG positive). However, the time of the infection cannot be predicted (ie, recent or past) since antibodies to EBNA usually develop after primary infection (recent) or, alternatively, approximately 5% to 10% of patients with EBV never develop antibodies to EBNA (past).
References:
https://www.cdc.gov/epstein-barr/laboratory-testing.html
Disclaimer:
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
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