Highlights from the AIDS meeting, July 22-27, Washington, D.C.
Cocaine hinders HIV fight
Cocaine use in HIV patients reduces amounts of much-needed immune cells and seems to hamper the virus-fighting activity of these and other cells and proteins, two studies show. Researchers tested 18 HIV-positive people who had similar T cell counts, 10 of whom were cocaine users. Compared with nonusers, the cocaine group had fewer newly trained T cells emigrating from the thymus, where nascent T cells get specific functions and are sent forth to fight disease. The finding suggests thymus function is impaired by cocaine, said Joumana Zeidan, an immunologist at the Vaccine & Gene Therapy Institute of Florida in Port St. Lucie. In the other study, gene analyses showed defective cell signaling that made cocaine users more prone to producing regulatory T cells, a variant form that actually dampens the immune reaction against HIV. These people also had more immune cells that were susceptible to undergoing programmed cell suicid