Efficiency of Different Serological Methods for Diagnosing Epstein−Barr Virus Infection and Atypical Serological Profiles

Diagnosis of Epstein-Barr virus (EBV) infection is primarily based on the detection of specific antibodies against EBV antigens associated with different stages of infection. This study compared enzyme-linked immunosorbent assay (ELISA) and immunoblot (IB) with the reference method, immunofluorescence assay (IFA), to evaluate their performance in defining EBV infection stages and atypical antibody profiles. Sera from symptomatic and asymptomatic pediatric patients were analyzed for EBV VCA (viral capsid antigen) IgM/IgG, EA (early antigen), and EBNA (Epstein-Barr nuclear antigen) IgG to determine EBV infection stages. Avidity ELISA for VCA IgG was performed to assess its utility for disease staging and in clarifying atypical antibody profiles. EBV DNA analysis was performed to investigate its complementary role alongside EBV serology. Almost perfect agreement was observed between ELISA and IFA (κ = 0.81) and between IB and IFA (κ = 0.82) for EBV staging, which further increased with the addition of VCA IgG avidity ELISA (κ = 0.97). During early primary EBV infection, PCR showed a sensitivity of 60% and may support diagnosis when combined with serological staging. In conclusion, the high concordance between IFA and ELISA including avidity suggests its suitability for routine diagnostics, particularly when IFA is impractical due to its technical complexity and cost.