Abstract des Autors

CD4+ cell counts and the CD4+/-CD8+ ratio are important markers of the progression of HIV infection. The effects of exercise and training on circulating CD4+ and CD8+ cell counts have been examined mainly in the context of young men performing aerobic exercise for sustained periods (often 1 hr) at or just below their ventilatory thresholds. During and immediately following such exercise, there is a small increase in CD4+ cell count but a larger increase in CD8+ cell count, leading to a decrease in CD4+/CD8+ ratio. During the 2 hrs following exercise, the CD4+ cell count usually returns to just below its resting level, with a larger decrease in CD8+ cell count, possibly reflecting a selective migration of cytotoxic CD8+ cells to lymphoid tissue or areas of muscle injury. As the intensity of physical activity increases, a larger increase in CD8+ cell count is observed. However, the response to prolonged moderate exercise is less dramatic. Other variables that increase the T-cell response to exercise are test repetition, female gender, a high level of initial fitness, eccentric exercise, and a high environmental temperature. Both cross-sectional comparisons and longitudinal training experiments suggest that vigorous aerobic training not only diminishes circulating CD4+ and CD8+ cell counts but also reduces the CD4+/-CD8+ ratio. Such findings suggest the need for moderation when using exercise in the treatment of patients with HIV infections. Verf.-Referat