Immunologic properties of Epstein-Barr virus-seronegative adults.

Epstein-Barr virus (EBV) seronegativity is rare in people > 20 years old. However, some persons remain EBV-seronegative for nearly their whole lives. The aim of this study was to examine properties of the immune system of EBV-seronegative adults that could contribute to long-term EBV seronegativity. Therefore, differential blood cell counts and lymphocyte subpopulations were determined, and the production of interferon (INF)-alpha and -gamma and interleukin (IL)-6 and -2 in a whole blood assay was investigated. Whereas no differences in the distribution of lymphocyte subpopulations between EBV-seronegative and -positive adults were found, a significant higher percentage of monocytes in EBV-seronegative adults was observed. Significantly more IFN-alpha and IL-6 were detected in culture supernatants of EBV-seronegative persons after stimulation with Newcastle disease virus. In contrast, no differences in the induction of the lymphokines IFN-gamma and IL-2 were seen. These data suggest that faster and higher production of IFN-alpha and IL-6 amy protect EBV-seronegative adults against EBV infection.