Interleukin-2 (IL-2) increases the number of CD4 cells in HIV-1 infected patients under highly active antiretroviral therapy (HAART) with a CD4 cell count over 200/mm3, but its activity in patients without antiretroviral therapy is unknown. This study will test the efficacy and safety of IL-2 in naïve patients with a CD4 count between 300 and 500/m3.

IL-2 is produced naturally in the body and helps CD4 cells multiply. In earlier studies in HIV-infection, most of the patients with a controlled viral load under antiretroviral therapy and a high level of CD4 cell count (over 200/mm3) who received IL-2, experienced an increase of their CD4 cell count superior to what is observed with antiretroviral therapy alone. The efficacy of IL-2 when the viral load is high and the patient is not receiving antiretroviral therapy is not known. The purpose of this multicentric national study is to compare the effects of IL-2 versus no treatment in HIV naïve patients. One hundred thirty HIV-1-infected patients, with a CD4 count between 300 and 500/mm3, will be randomly assigned to one of two treatment groups : IL-2 or no treatment. The group with IL-2 will receive a dose of 4.5 million international units by subcutaneous injection twice a day for 5 days (up to a total of 5 cycles, ending at Week 96), the first three cycles 8 weeks apart. Evaluation will be done at week 96. The primary endpoint is the proportion of patients reaching an absolute CD4 count below 300/mm3 at Week 96. Secondary endpoints include the occurrence of HIV-related events, drug safety and the evolution of CD4 cells and of HIV RNA and HIV DNA loads over time.

Inclusion Criteria:

• Adult patients with proven HIV-1-infection
• No prior exposition to antiretrovirals
• CD4 cell count between 300 and 500/mm3
• Signed written inform consent

Exclusion Criteria:

• Pregnancy