OBJECTIVES: HIV-infected individuals are at higher risk of non-AIDS diseases associated with procoagulant status. Microparticles are elevated in disorders associated with thrombosis (e.g., cardiovascular diseases). We investigated the association between microparticle levels in untreated and treated HIV-infected subjects, and determined the association with immune status, viral replication, and duration of antiretroviral therapy. PATIENTS AND METHODS: We included 144 HIV-infected subjects, including 123 on antiretroviral therapy (ART) and 21 before treatment initiation. A control group of 40 HIV-negative healthy adults matched for age and sex was used for comparison of microparticle levels. Treated subjects were divided into five groups depending on the period of antiretroviral exposure. Statistically significant differences were determined by Kruskal-Wallis test and Chi2 test. The relation between microparticles and other parameters was assessed using Spearman's coefficient of correlation. RESULTS: Microparticle levels were significantly higher in treated and untreated HIV-infected subjects than in non-HIV-infected controls (P<0.001). The microparticle level was similar between the groups on treatment (P=0.913). No association between the microparticle level and CD4+ count, CD4+/CD8+ ratio, number of HIV-1 RNA copies, or duration of exposure to antiretroviral treatment was observed. CONCLUSION: Increased levels of microparticles may be due to processes independent of viral replication and CD4+ cell count, and microparticle release might persist even during viral suppression by antiretroviral treatment. Elevated microparticle levels might occur in response to other triggers.

Department of hematology Faculty hospital Brno and Faculty of medicine Masaryk University Brno Jihlavska 340 20 62500 Brno Czech Republic

Department of infectious diseases Faculty hospital Brno and Faculty of medicine Masaryk University Brno Jihlavska 340 20 62500 Brno Czech Republic

Institute of biostatistics and analyses Faculty of medicine Masaryk University Brno Kamenice 126 3 62500 Brno Czech Republic

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