[The latent dysfunction of Epstein-Barr virus (EBV)-specific cellular immunity in asymptomatic human immunodeficiency virus (HIV) carriers].

Cellular immunity is known to play a critical role in regulating Epstein-Barr virus (EBV) in the state of latent infection. Activity of EBV-specific cellular immunity decreases as the clinical stages of human immunodeficiency virus (HIV) infection progress, and many complications are induced by reactivated EBV in the late stages of HIV infection. However, in asymptomatic HIV carriers, some show the reduced activity of cellular immunity against EBV, while others still show normal range of the activity even in the presence of abnormality in other immunological parameters. In order to assess early immunological abnormality against EBV in these patients, asymptomatic HIV carriers with normal range of EBV-specific cellular immunity were studied in comparison with that in EBV seropositive healthy controls. 1. All of 4 asymptomatic HIV carriers showed normal range of EBV-specific cellular immunity as seen in healthy controls. 2. Asymptomatic HIV carriers had significantly elevated serum antibody titers to EBV-specific nuclear antigen (EBNA)2, viral capsid antigen(VCA), early antigen(EA), indicative of serological reactivation of EBV. 3. The number and percentage of peripheral CD4 positive lymphocytes, CD4/CD8 ratios were markedly decreased in asymptomatic HIV carriers. 4. In the presence of immunosuppressive agents, 4-deoxy phorbol ester(4-DPE), drastic decrease of EBV-specific cellular immunity was observed in asymptomatic HIV carriers at the concentration which did not affect that of healthy controls. 5. Reduced activity of EBV-specific cellular immunity induced by 4-DPE had no relation with surface marker expression on cytotoxic T cells which serve as cell-to-cell adhesion molecules. Based on these results, it is suggested that there is latent dysfunction of EBV-specific cellular immunity in asymptomatic HIV carriers, who seems to show normal range of immunity in usual assays.