Highly active antiretroviral therapy has improved the morbidity and survival of patients with the human immunodeficiency virus (HIV) infection. Currently available antiretroviral agents can suppress viral replication and partially reverse cellular immunity defects in HIV patients. Immune-based therapy with interleukin-2 when used as adjunctive therapy to antiretroviral therapy may further improve immune responses, as demonstrated by an increase in CD4(+) T-lymphocyte counts in recent clinical trials.