BACKGROUND: HIV infection causes chronic activation of cytotoxic CD8+ T-lymphocytes, which is partly responsible for the hallmark of the disease--progressive loss of CD4+ T-lymphocytes. The aim of this study was to evaluate an influence of HIV infection and long-term antiretroviral therapy (HAART) on expression of the activation molecules CD38 on CD8+ T-lymphocytes. METHODS: A group of 16 HIV-positive patients treated with HAART was followed for 12 months. Also, we examined 10 persons with a newly diagnosed HIV infection that were not treated with HAART. Expression of CD38 molecules on CD8+ T-lymphocytes was determined with five-parameter cytometric analysis using monoclonal antibodies as well as their mean fluorescence intensity (MFI). RESULTS: The percentage of CD8+/CD38+ T-lymphocytes in HIV-positive patients treated with HAART significantly decreased during the follow-up period from 46.1 I 3.7 to 35.2 I 3.8 (p = 0,01). Furthermore, the percentage of these cells correlated negatively with the number of CD4+T-lymphocytes at the beginning and the end of the study (r = -0,679, p < 0.01; r = -0,51, p = 0,05, respectively). There was no correlation between these parameters in persons with newly diagnosed HIV infection. However, the percentage of CD8+/CD38+ T-lymphocytes in these patients was significantly higher than in persons treated with HAART (68.5 I 5.3 vs. 35.2 I 3.8, p < 0,01). CONCLUSIONS: Our findings support the importance of expression of CD38 antigen on CD8+ T-lymphocytes as a biological and clinical marker of HIV infection and indicate its usefulness for monitoring of the efficacy of HAART therapy.

Dept Infectious Diseases 1st Medical Faculty Charles University Prague Budínova 2 180 81 Prague 8 Czech Republic