Atypical Profile Problem in Serological Diagnosis of EBV

Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. Burkitt's lymphoma, nasopharyngeal carcinoma and post-transplant lymphoproliferative diseases are also associated with EBV. Diagnosis is frequently based on detection of specific antibodies. Using three parameters (anti VCA-IgM, anti VCA-IgG and anti EBNA-1 IgG), it is possible to define infection status and diagnose acute or past infection. However, sometimes the detection of atypical serological profiles makes it difficult to interpret these results. This study aims to evaluate the serological profiles of patient sera suspected of EBV infection and to determine atypical profiles. Sera of 2749 patients were analyzed between January 2014 and August 2016, in the Dokuz Eylul University Hospital Central Laboratory and evaluated retrospectively. Serum samples were tested for EBV VCA IgM and EBV VCA IgG antibodies with immunofluorescence test (Euroimmun, Germany), EBNA-1 IgG antibodies with enzyme immunoassay (Euroimmun, Germany). Medical files of the patients with two or more samples and have an atypical profile were reviewed. Patients were grouped as no EBV infection, acute infection, past infection and atypical serologic profile according to three routine laboratory assays (VCA IgG, VCA IgM and EBNA-1 IgG). Out of 2794 subjects 1334 (48.5%) were female and 1415 (51.5%) were male, with mean age 30 (< 1-89 years, median value: 27). The distribution of the results was; 72.5% past infection, 10.9% absence of EBV infection and 5.2% acute infection and 11.4% showed atypical serologic profile. Among the atypical profiles, isolated VCA-IgG positivity was the most frequent pattern detected in 7.9% which is followed by 2.7% of the cases with all three markers positive and 0.8% with isolated EBNA-1 IgG positivity. Off the patients, 72.5% were seropositive for EBV and this result is consistent with the seroprevalence studies previously conducted in Turkey. The rate of atypical profiles was 11.4% which is close to the result (15%) of another study performed in Izmir. Nearly one third of the patients with atypical serological profile had an immune disorder and it was possible to reach a conclusion only among half of the patients during serological follow-up. This study points out that clinical diagnosis and serologic follow-up is important for the interpretation of the atypical profiles