Treatment with HIV-infection with protease inhibitors is associated with high blood lipids and higher chance for cardiovascular complications. The RASSTER study aims to investigate the effect of switching the protease inhibitor lopinavir/ritonavir to raltegravir on vessel wall function and inflammation,and activation of the immune system. we hypothesize that with this intervention these parameters will improve. Since decreased vessel wall function and inflammation are initial steps in the process of atherosclerosis, it is important to know this data when treating HIV-infected patients.

Fixed dose combination lopinavir/ritonavir (LPV/r) is a widespread used antiretroviral drug belonging to the class of protease inhibitors (PIs). PIs are associated with an increased risk of myocardial infarction. However, data is available suggesting increased levels of plasma lipids are not the sole explanation for this observation. Treatment with LPV/r might lead to a decrease of endothelial function as well, thus explaining the increased risk of myocardial infarction besides increased plasma lipids. Raltegravir is a registered antiretroviral drug with no known cardiovascular side effects. We hypothesize that switching LPV/r to raltegravir in HIV-infected patients with suppressed plasma viral load (<50 copies/ml) will lead to an improvement of endothelial function.

Objective:

• First, to assess the effect of the switch of lopinavir/ritonavir to raltegravir on endothelial function.
• Second, to assess the effect of the intervention mentioned above on markers of endothelial function; immune activation; chronic inflammation; and, on plasma HIV-RNA below the cut-off of 50 copies/ml.

Inclusion Criteria:

• Age ≥ 18 years
• HIV-1 infection
• Treatment with antiretroviral regimen containing lopinavir/ritonavir for at least the previous 3 months
• No other protease inhibitors besides lopinavir/ritonavir in antiretroviral regimen
• Subjects must have a minimum period of viral suppression (plasma HIV-RNA < 50 copies/ml) of 6 months
• Subjects will not have a history of virological failure on antiretroviral therapy
• Results of previous resistance testing allowing replacement of lopinavir/ritonavir by raltegravir
• CD4+ cell count > 200 cells/µL
• Signed informed consent

Exclusion Criteria:

• Pregnancy
• Breastfeeding
• Raltegravir hypersensitivity
• Treatment of underlying malignancy
• Renal insufficiency requiring dialysis
• Acute or decompensated chronic hepatitis (Child-Pugh score C)
• Modification of antiretroviral regimen in the previous 3 months