Effects of high and low stress on proinflammatory and antiinflammatory cytokines.

The effects of stress, which varies throughout an academic year, on proinflammatory and antiinflammatory cytokines were examined in 44 medical students. This was tested by comparing stimulated cytokines during a baseline period, stress period, and poststress vacation period. During the stress period, compared with the baseline period, levels of IL-6 were reduced, while levels of IL-10 were elevated. During the poststress vacation period, compared with the stress period, levels of IL-6 and TNF-α were increased. However, the changes in stress-related psychological and physiological variables were not significantly associated with changes in levels of proinflammatory and antiinflammatory cytokines. These results suggest that vacation is more likely to have a counterstress effect on proinflammatory cytokines than on an antiinflammatory cytokine and that a stressor may affect changes in immune function independently of self-reported stress.