HIV infection is associated with an immune activation and an inflammatory response - despite an active antiretroviral therapy - which may lead notably but not exclusively to cardiovascular diseases. It has been shown that the use of Protease Inhibitors (PI) instead of Non Nucleosidic Inhibitors (NNRTI) may increase the risk of myocardial infarction. Platelets may play a role in the occurrence of the inflammatory state: they contain big amounts of chemokines, growth factors, and adhesion proteins. Today, the contribution of platelets to the inflammatory state associated with HIV infection has been little studied. Thus, it has been shown that platelets in HIV patients are able to release interleukin (IL)-18. The group has shown with others that the platelet function could be altered during HIV infection. Inversely, it doesn't know how antiretroviral therapy interacts with platelets.

The aim of the study is to evaluate, according to the antiretroviral therapy, the impact on the platelets activation markers.

Inclusion Criteria:

• Unchanged antiretroviral therapy for at least one year
• Plasmatic viral load < 40 copies/ml.
• signature of informed consent

Exclusion Criteria:

• Hepatitis B Virus (HBV) and/or Hepatitis C Virus (HVC) coinfection

Study populations:

• HIV patients under 2 NRTIs (Nucleosidic analogs of Transcriptase Reverse Inhibitors) and 1 PI or 2 NRTIs and 1 NNRTI, for at least one year with a plasmatic viral load under 40 cp/ml.
• Untreated HIV patients