Journal of IMAB (Dec 2018)
Role of anti-EA-(D) IgM and anti-EA-(D) IgG tests in patients with primary EBV infection, lymphomas and immunosuppression
Abstract
Purpose: The EA (early antigen) is expressed during the lytic phase of the EBV life cycle, together with VCA (viral capsid antigen) and MA (membrane antigen). Antibodies to EA (D) IgG occur in the course of primary infection, but not in all patients. The titers increase in the first 3-4 weeks and usually last about 3-4 months. Their presence is also associated with reactivation of the infection due to impaired immune control of the viral replication. The aim of this study was to compare the primary immune response against the major antigens (VCA) and EA (D) in patients with clinically proven primary infection and to define the antibody response to the EA (D) antigen as a marker for reactivation in patients at risk. Materials/Methods: We examined 86 persons with lymphomas, incl. Hodgkin's lymphoma and non-Hodgkin's lymphoma, immunosuppressed patients, mainly with AML (acute myeloid leukemia) and primary infection (infectious mononucleosis, IM) patients. We used an indirect ELISA for anti-EA (D) IgM/IgG and anti-VCA IgM/IgG (Euroimmun, Germany). Results: Patients with аnti-EA(D) IgM were 29.1% (95% CI:19.8% - 39.9%, n=25) while patients with аnti-EA(D) IgG were 23.3% (95% CI:14.8%-33.6%, n=20) (p>0.05). As expected, younger individuals with IM diagnosis predominated among the positive patients. We found isolated аnti-EA(D) IgM in four persons (with lymphoma and immunosuppression) and isolated аnti-EA(D) IgG in five patients. Conclusion: The routine diagnostic tests used to detect antibodies to VCA have a much better diagnostic value in defining a primary infection. Use of antibodies against EA (D) in case of isolated anti-VCA IgM and anti-VCA IgG needs further evaluation. Use of anti-EA (D) IgG as a reactivation marker should be compared with Real-time PCR results.
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