HAART is often successful in decreasing viral load (level of HIV in the blood), but these drugs have not been able to restore the immune systems of HIV-infected patients. IL-2 is a substance naturally produced by the body's immune cells. In ACTG 328, IL-2 is tested to see if it can increase the number of CD4 cells and "boost" a patient's immune system. This study is a follow-up to ACTG 328 so that patients who are benefiting from IL-2 can continue to take it and patients in the control group who do not receive IL-2 can start taking it.