Significance of the “isolated EBNA-1 IgG” pattern in past EBV infection

Abstract

The ELISA screening detection of anti-EBNA-1 IgG in the absence of VCA IgG and IgM is rare but may lead to doubts in interpretation.We used immunoblotting to characterise 23 serum samples with “isolated EBNA-1 IgG” upon ELISA screening, and found that all showed VCA anti-p23 and 13 (56.6%) also showed VCA anti-p18 antibodies. It therefore seems impossible for a sample to show anti-EBNA-1 IgG without anti-VCA IgG antibodies. Furthermore, although anti-p18 antibodies are thought to develop later and therefore considered to be markers of past infection, about 1% of all previously infected EBNA-1 IgG-positive patients do not have them.

Keywords

• immunoblotting
• EBNA-1
• EBV
• mononucleosis
• serological pattern