Sympathetic reactivity to acute stress and immune response in women.

We evaluated if the effects of acute stress on immune parameters were apparent in only the women who showed concomitant and substantial sympathetic nervous system activation and after statistical adjustment for changes in plasma volume. Nineteen women in the follicular stage of their menstrual cycles were assessed for immunological responsiveness to a series of three 3-minute psychological tasks, which reliably elicit cardiovascular and neuroendocrine stress responses. Women were classified as high or low sympathetic reactors based on their cardiovascular and neuroendocrine responses to one of the three tasks, a public speaking task. The stress-induced decreases in CD4+ percentage and increases in natural killer cell number and cytolytic activity were only apparent among the high reactors. Further analysis adjusting for alterations in plasma volume changes showed that the increase in NK cell number remained. Stress-induced proliferative responses to pokeweed mitogen and phytohemagglutinin were not more apparent among high reactors. These results are consistent with the hypothesis that the sympathetic nervous system plays a direct role in modulating the short term response to stress of some indices of the immune system in women.