Individuals treated with interleukin-2 (IL-2) plus highly active antiretroviral therapy (HAART) have significantly fewer resting CD4+ T cells in their bloodstream which harbor HIV than patients receiving HAART alone, according to a study of 26 patients conducted at the National Institute of Allergy and Infectious Diseases (NIAID). Resting CD4+ T cells are among the "safe havens" where HIV may persist for years - sewn into the cells' genes - despite aggressive three-drug antiretroviral therapy.
In resting CD4+ T cells taken from the bloodstream ("peripheral blood") of a small number of study patients receiving IL-2 plus HAART, the researchers have been unable to find HIV capable of replicating, even when they have looked for the virus in millions of cells with sensitive laboratory procedures.
Anthony S. Fauci, M.D., NIAID director and chief of the NIAID Laboratory of Immunoregulation (LIR), plans to present these new findings at the 36th Annual Meeting of the Infectious Diseases Society of America in Denver, Colo., on Sunday, November 15 at 8:30 a.m. Mountain Time. The lead LIR scientist on the new studies is Tae-Wook Chun, Ph.D., who, with Dr. Fauci and other colleagues, has published several seminal papers on latent reservoirs of HIV.
The NIAID team studied two different groups of HIV-infected patients, 12 receiving HAART (generally a combination of at least three antiretroviral drugs including a protease inhibitor) and 14 receiving HAART plus IL-2, administered either intravenously or subcutaneously. IL-2 is a regulatory protein of the immune system produced in the body by T cells. IL-2 has potent effects on the proliferation, differentiation and activity of a number of immune system cells, notably T cells. The 14 patients on HAART plus IL-2 received doses of IL-2 totaling 3 to 18 million international units per day during five-day treatment cycles, followed by a rest period of at least eight weeks before the next treatment cycle.
Contact: Greg Folkers
NIH/National Institute of Allergy and Infectious Diseases