Association of T Cell Proliferative Responses and Phenotype with Virus Control in Chronic Progressive HIV-1 Disease

The role of T cell immunity in virus control during chronic infection was examined in 79 human immunodeficiency virus type 1 (HIV-1)-infected subjects randomized to receive antiretroviral therapy. HIV-1 p24-specific responses were detected in 20% of the subjects at baseline, increasing to 28% of the subjects at weeks 16-24. Induction of virologic suppression was associated with lower plasma HIV-1 RNA levels and a higher percentage of Fas⁺ CD8 ⁺ T cells at baseline, whereas maintenance of suppression was associated with higher CD4⁺ T cell counts and, marginally, with a higher percentage of Fas⁺ CD4⁺ T cells at weeks 16-24. These findings indicate that Fas coexpression on T cells, in addition to plasma HIV-1 RNA levels and CD4⁺ T cell counts, may predict virologic outcome.