Anti-HIV therapy has been very successful in treating HIV positive patients and in keeping viral load (level of HIV in the blood) low. However, anti-HIV drugs cannot completely rid the body of the virus, and the immune system is never completely restored in HIV positive patients. Doctors hope that giving patients recombinant interleukin-2 (rIL-2) in addition to their anti-HIV therapy will help improve their immune systems and keep them healthier over a longer period of time. rIL-2 is a hormone naturally produced by the body during an immune response to a microbial infection.