A risk-benefit assessment of interleukin-2 as an adjunct to antiviral therapy in HIV infection

Immunomodulation has become a major focus of HIV research in an effort to a ugment, boost or restore the patient's damaged immune system. Recombinant i nterleukin-2 is currently being studied in phase II/III trials in HIV-infec ted patients. Several clinical studies have demonstrated that intermittent regimens are associated with marked rises in CD4+ cell counts without an in crease in viral load. Most of these studies employ 5 consecutive days of in terleukin-2 therapy by continuous intravenous infusion or subcutaneous inje ction, repeated every 8 weeks. An alternative strategy is the daily adminis tration of low doses of interleukin-2, but clinical experience with this re gimen is limited. Interleukin-2 administration can adversely affect virtually every organ sys tem, requiring aggressive supportive care. A variety of administration stra tegies and interventions are being evaluated to minimise toxicity. Currently, no clinical end-point data are available for interleukin-2 in HI V-infected patients. Until phase III studies are completed, interleukin-2 c an be used in the research setting as an immunomodulator and adjunct to ant iretroviral therapy. Its potential to activate latently infected cells and promote HIV eradication from reservoir sites is also an important area for further study. If clinical benefit can be demonstrated, interleukin-2 could be useful as an adjunct to antiretroviral therapy if adverse effects can b e minimised and therapy can be given infrequently on an outpatient basis.