Prolonged statin administration does not act on the cell-mediated immunity of HIV-infected dyslipidemic patients treated with a steady and effective highly active antiretroviral therapy. A two-year prospective study of statin versus fibrate administration, versus a dietary/exercise program

OBJECTIVE: To assess whether statin administration for HIV-associated hyperlipidemia has long-term effects on immune recovery (as expressed by the trend of mean CD4+ lymphocyte count), in patients on a virologically-active HAART regimen since 12 months or more. METHODS: Single-centre, open-label, prospective study of 301 hyperlipidemic patients treated with statins (99 cases, with a predominant hypercholesterolemia), fibrates (116 subjects, when hypertriglyceridemia prevailed), or a isolated dietary/exercise program (86 patients, used as a control group). Neither epidemiological nor clinical, virological, or immunological differences were detected among the three study groups at baseline. During the subsequent follow-up, patients were excluded from evaluation should virological efficacy was not maintained, and/or initial hypolipidemic therapy was modified or interrupted for any reason. RESULTS: The quarterly assessment of mean CD4+ lymphocyte count did not disclose any statistically significant difference among the three study groups, since baseline and until at least 24 consecutive months of follow-up. Our data tend to exclude relevant in vivo negative activities of statins on immune system recovery of HIV-infected individuals who undergo a virologically effective HAART treatment. CONCLUSIONS: Multiple, pleiotropic features have been attributed to both statins and fibrates, and also apparently significant effects on laboratory markers of HIV disease progression have been recently claimed or expected. Despite some preliminary in vitro and ex-vivo models, both the main hypolipidemic classes administered for the management of HIV-related dyslipidemia (both statins and fibrates) do not seem to act significantly on clinical immune response of patients successfully treated with HAART. Multifactorial pathways are expected to interact with the cell-mediated immune system of HIV-infected patients undergoing successful HAART, and further studies are needed to elucidate whether more subtle immune effects might be prompted by a long-term administration of hypolipidemic drugs in this speciasl setting.