Examining the current role of interleukin-2 in the treatment of HIV infection?

Objective: To review the literature and examine the role of interleukin- 2 (IL-2) in the therapy of human immunodeficiency virus (HIV) infection. Data Source: A MEDLINE (1966-1997) and an AIDSLINE search of the English-language literature was performed to identify reviews and research articles. Abstracts from the International Conference on AIDS and the Interscience Conference on Antimicrobial Agents and Chemotherapy were also reviewed. Study Selection: All articles and abstracts were considered for possible inclusion in the review. Data Extraction: Clinically relevant articles from abstracts to clinical trials were reviewed if they contained pertinent information on IL- 2 in the treatment of HIV infection The research needed to meet the following criteria to be selected for a more detailed assessment: clinical trial, concomitant antiretroviral therapy, and publication as a manuscript. Abstracts were excluded from detailed discussion. Data Synthesis: Currently available drugs in the therapy of HIV infection focus on antiviral activity; their effects are frequently limited by drug toxicity and the development of resistance. Through a different mechanism, IL-2 may be a potential therapy in the battle against HIV. Early studies found no benefit from IL-2 in HIV- infected patients; however, its role in the treatment of HIV is being reassessed. Clinical trials using higher doses of IL-2 have demonstrated immunologic, viral, and T-lymphocyte changes. Conclusions: Clinical trials exploring the role of IL-2 in HIV infection are rapidly evolving. Current data suggest that therapy with 6-12 million IU/day of IL-2 for five days every eight weeks may lead to sustained increases in CD4⁺ cell count in patients with CD4⁺ cell counts ≥ 200/mm³. Since most studies were performed prior to the current recommendations of a three-drug regimen for HIV infection, the effect of IL-2 in combination with this regimen needs to be assessed. Thus, many questions still remain to be answered before defining the exact role of IL-2 in the therapy of HIV infection.