Cd8⁺ lymphocyte activation at human immunodeficiency virus type 1 seroconversion: Development of Hla-Dr⁺ Cd38 Cd8⁺ cells is associated with subsequent stable Cd4⁺ cell levels

Subsets of activated CD8⁺ lymphocytes defined by membrane expression of the activation antigens HLA-DR and CD38 were counted by three-color flow cytometry in homosexual men who subsequently became seropositive for human immunodeficiency virus type 1 (HIV). Profound CD8⁺ cell activation was seen in all subjects at seroconversion and 6 and 12 months later. The HLA-DR⁺ CD38⁺ CD8⁺ cell population, which has potent direct HIV cytotoxic T cell activity, was markedly elevated at seroconversion in all subjects. In some men, these levels remained elevated throughout the first year of infection. During the next 5 years, these men had stable CD4⁺ cell levels, whereas the others did not. Long-term survivors (seropositive for 9 years, >800 CD4⁺ cells/mm³) also had elevated levels of this subset, despite few other activated CD8⁺ cells. Thus, selective elevation of HLA-DR⁺ CD38 CD8⁺ cells was a marker of subsequent stable HIV disease.