STABILITY OF INDIVIDUAL-DIFFERENCES IN CELLULAR IMMUNE-RESPONSES TO ACUTE PSYCHOLOGICAL STRESS

To determine the stability of individual differences in cellular immun e reactions to acute mental stress, we correlated enumerative and func tional lymphocyte responses to an evaluative speech task across two ex perimental sessions scheduled 2 weeks apart in 30 young men. Relative to pretask baseline measurements, the speech stressor elicited a dimin ished proliferative response to phytohemagglutinin and concanavalin A, a decrease in circulating CD19 lymphocytes, and an increase in both C D8 and CD56 lymphocytes across the two occasions of testing. Test-rete st correlations were significant for the magnitude of change in prolif erative response to PHA (r = .50, p < .005) and in numbers of circulat ing CD8 and CD56 cells (r = .53, and .42, respectively; p's < .02). Co ncomitant cardiovascular responses also correlated significantly over the two experimental sessions (heart rate: r = .78, p < .0001; systoli c and diastolic blood pressure: r = .79 and .48, p < .0001 and .007). These data provide initial evidence that interindividual variability o f cellular immune responses to acute psychological stress is moderatel y reproducible on retesting and may therefore denote a stable dimensio n of individual differences.