National Institutes of Health (NIH) scientists report that brief, widely-spaced courses of the experimental immune-boosting drug interleukin-2 (IL-2) allow people with HIV to maintain near normal levels of a key immune system cell for long periods. The researchers, from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and the Warren G. Magnuson Clinical Center, describe their findings in the May 1 issue of the journal Blood. “These data provide strong evidence that IL-2 therapy, which can be self-administered by patients, could be an important adjunct to highly active antiretroviral therapy (HAART),” says NIAID Deputy Director John R. La Montagne, Ph.D. The new report summarizes the experience of 77 HIV-positive individuals who enrolled in extension phases of three long-running AIDS clinical trials. Participants were taught to inject themselves subcutaneously with IL-2 twice daily in 5-day-long cycles. Cycles were initiated as often as necessary to maintain levels of immune cells called CD4+ T cells at predetermined, individually tailored amounts. HIV infection causes progressive loss of CD4+ T cells. Without enough of these “helper” immune cells, people with HIV disease have a hard time fending off infections. IL-2 can boost CD4+ T cell levels, with the goal of improving overall immune health.
