A Phase III Multicenter Randomized Study of the Biological and Clinical Efficacy of Subcutaneous Recombinant, Human Interleukin-2 in HIV-infected Patients with Low CD4+ Counts Under Active Antiretroviral Therapy (SILCAAT) The purpose of this study is to compare the effects of subcutaneous recombinant interleukin-2 (SC rIL-2) and no SC rIL-2 o­n disease progression and death over an average follow-up period of 6-7 years period in patients with HIV-1 infection o­n stable antiretroviral therapy who have a CD4+ cell count between 50 and 299 cells/mm3 and a viral load <10,000 copies/mL.