An Immunologic Study of Treatment-Naive HIV Patients Starting a Darunavir/Ritonavir- or Efavirenz-Based HAART

• Change (>=10%) in the proportion of activated HLA-DR+CD38+CD8+ T-cells [ Time Frame: Baseline and Week 24 ] [ Designated as safety issue: No ]
  

• Change (>=10%) in the proportion of activated HLA-DR+CD38+CD8+ T-cells [ Time Frame: Baseline, Week 12, and Week 48 ] [ Designated as safety issue: No ]
  
• Change in peripheral T-lymphocyte immune phenotype [ Time Frame: Baseline, Week 12, Week 24 and Week 48 ] [ Designated as safety issue: No ]
  
• Change in peripheral T-lymphocyte turnover [ Time Frame: Baseline, Week 12, Week 24 and Week 48 ] [ Designated as safety issue: No ]
  

This is an ex-vivo study (study which takes place outside the organism and records immune parameters from stored blood and cells of a defined population without any intervention by the researcher) to evaluate the kinetics (study of the rate of change) of immune recovery quality and function in stored plasma blood samples of treatment-naive (not previously treated with antiretroviral drugs) patients with advanced human immunodeficiency virus (HIV) infection starting a Darunavir/Ritonavir (DRV/r)- or Efavirenz (EFV)-based highly active antiretroviral therapy (HAART) regimen. In previously stored plasma blood samples, the role of DRV/r compared with EFV in reducing T-lymphocyte activation, DRV/r compared with EFV in recovering T-lymphocyte immune phenotype in peripheral blood and thymic production, and DRV/r compared with EFV in recovering T-lymphocyte function (functional immunity) will be studied. Blood samples will be analyzed before (baseline) and up to 48 weeks after initiating HAART.

Each patient will receive orally administered (given by mouth) regimens of either Darunavir/Ritonavir (DRV/r) + Tenofovir/Emtricitabina or Efavirenz (EFV) + Tenofovir/Emtricitabina.