Immunophenotype of progression to AIDS:: deficiency, activation and dysfunction of CD4 and CD8 T-cells

Introduction. One key piece of information required when deciding whether to initiate antiretroviral therapy is the risk of AIDS. The aim of this study was to better characterize the baseline immunophenotypic profile of patients with progression to AIDS. Material and methods. A cross-sectional analysis of the distribution of functional subpopulations of CD4+ and CD8+ T-lymphocytes in 85 intravenous drug addicts with HIV infection. The values observed on patient enrolment in a prospective study were analyzed. Those patients who progressed and did not progress were compared to the HIV-negative controls. Lymphocyte subpopulations were studied by flow cytometry, including the markers: CD3, CD4, CD7, CD8, CD45R0, CD38, HLA-DR and CD25. Results. The immunophenotypic profile that precedes progression to AIDS was mainly characterized by an increase in memory (CD45R0) activated cells and total activated CD4+ and CD8+ cells, and by an increase of T CD4+ cells that have loss expression of markers as receptor or the differentiation marker CD7 (CD7-). Patients not meeting laboratory criteria to initiate antiretroviral therapy (> 350 CD4+ T-cells and < 30,000 HIV-ARN-copies/ml) also showed increased levels of CD4+ and CD8+ activation subsets (CD4+CD38+DR+, CD8+CD38+). Discussion. The fact that immunological activation may contribute to immunological and clinical deterioration of HIV-positive patients might be an additional factor which should be taken into account when deciding whether to initiate antiretroviral therapy.