• CD4 cell count [ Time Frame: From Basal to 48 week (last visit) every 3 months ] [ Designated as safety issue: No ]
  

• Epidemiologic variables: Age, sex, time of HIV diagnosis/duration of HIV infection, duration of antiretroviral treatment with HAART, duration of treatment with a PI, HIV infection status/CDC disease stage. Epidemiologic, virologic, and immunologic data [ Time Frame: Baseline ] [ Designated as safety issue: No ]
  
• Virologic and immunologic variables: Time/duration of viral suppression, nadir CD4+ count, change in CD4+ count (absolute and percentage) since initiation of antiretroviral therapy, since initiation of HAART, and since achieving and undetectable viral [ Time Frame: From Basal to 48 week (last visit) every 3 months ] [ Designated as safety issue: No ]
  
• Apoptotic variables: Cell death in CD4 and CD8 cells, defined as the percentage of cells which present a weak DIOC measurement (DIOC low) after 1 or 4 days of culture. [ Time Frame: From Basal to 48 week (last visit) every 3 months ] [ Designated as safety issue: No ]
  
• The toxicity parameters will be evaluated: Hematology: Hematocrit, red blood cell count, hemoglobin, MCV, lymphocyte, platelet count, quick Index. • Biochemistry: glucose, total cholesterol, HDL and LDL cholesterol, triglycerides, urea, creatinine, A [ Time Frame: From Basal to 48 week (last visit) every 3 months ] [ Designated as safety issue: Yes ]
  
• Clinical adverse effects and clinical events [ Time Frame: From Basal to 48 week (last visit) every 3 months ] [ Designated as safety issue: Yes ]
  

One of the many adverse consequences of the human immunodeficiency virus (HIV) infection is the increase in the rate of lymphocyte cell death (Badley AD, Blood. 2000; 96:2951-64). Increased lymphocyte death is associated with the level of activation of the immune system (Gougeon ML. Nat Rev Immunol. 2003: 3:392-404), along with the disregulation of the cytokine network and a plethora of cytotoxic effects induced by HIV proteins (Badley AD, Blood. 2000; 96:2951-64). Hence, cell death can be observed in vivo not only in CD4+ cells, which are the main target of HIV, but also in CD8 T cells. Current knowledge suggest that immune activation and different mechanisms of cell death play a determinant role in T-lymphocyte (CD4+) loss during HIV infection and recovery after HAART (Bofill M et al AIDS. 1996 :827-34).

Highly active antiretroviral treatment (HAART) induces a decline in the level of immune activation and lymphocyte apoptosis in HIV-infected patients as a result of a reduction in viral replication (Kolber MA, et al, Clin Immunol. 2007 [Epub ahead of print]). This reduction contributes to the recovery of immune system associated with antiretroviral therapy. In addition to this effect, which is induced through the reduction in viral load, antiretroviral therapy has been implicated in the regulation of apoptosis in different cell types, inhibiting or activating the process and influencing treatment efficacy and toxicity (Petit F, et al.Trends Pharmacol Sci. 2005. 26:258-64).

Interestingly, it is not always true that antiretroviral therapy and viral suppression are associated with progressive immune recovery. Approximately 30% of patients present a paradoxical response to treatment, achieving progressive increases in immunity (measured by CD4+ count) despite failing to achieve viral suppression, or, vice versa, patients who maintain or reduce CD4+ cell count despite achieving viral suppression. Indeed, it is well known that higher CD8 activation is associated with fewer treatment-mediated CD4 gain. Each 10% increase in activated CD8+HLADR+CD38+ mean 90 fewer CD4 cell gained (Hunt PW et al J Infect Dis. 2003. 187:1534-43). The failure of recover CD4 T cells may rely on a incomplete viral suppression than could be responsible for increased immune activation and lymphocyte death. Recently, it has been pointed out that intensification strategies may be useful in reducing activation and improving CD4 T cell recovery (Kolber MA, et al, Clin Immunol. 2007 [Epub ahead of print]).