Expansion of activated T lymphocytes (CD3 + HLA/DR +) detectable in early stages of HIV-1 infection.

The phenotypic characterization of lymphocyte subsets in relation to different clinical stages of HIV infection has mainly focussed on CD4 and CD8 cells. Some reports focus on expansion of activated T lymphocytes in AIDS patients. Yet there is no detailed knowledge whether such changes occur also in earlier stages of HIV infection. In order to describe the kinetics and possible pathogenetic meaning of this subset when related to all distinct chronologic stages, we performed two-color flow cytometric lymphocyte differentiation in 173 HIV-infected patients and 30 healthy controls. All subjects were classified according to the Walter Reed (WR) system. Our results show that a significant increase of activated T lymphocytes (CD3 + HLA/DR +) occurs early, in WR1 and WR2, thus preceding the clinically relevant CD4 depletion. This increase is paralleled by an expansion of CD8 + Leu7 + cytotoxic cells. We conclude, that early changes of lymphocyte subsets are detectable in addition to inversion of the CD4/CD8 ratio. The possible pathogenetic meaning including the question of possible autoimmune mechanisms is discussed.