Altered human neutrophil function in response to acute psychological stress.

OBJECTIVE: To examine the effects of an acute laboratory psychological stress task on neutrophil function, specifically phagocytosis of Escherichia coli and stimulated superoxide production in human neutrophils. There is mounting evidence that acute stress is associated with short-term increases in a number of immune indices. METHODS: Participants were 40 (n = 20 females) university students (mean age, 25.9 ± 4.56 years). Blood samples to determine neutrophil function by flow cytometry were taken at the end of resting baseline, during an acute stress task, and during recovery. The stress task was a 10-minute time-pressured mental arithmetic challenge with social evaluation. RESULTS: There was an acute increase in phagocytic ability, p = .047, η(2)p = 0.076, and a reduction of superoxide production, p = .026, η(2)p = 0.101, associated with the stress task relative to baseline. CONCLUSION: These findings suggest that neutrophil bactericidal function may be sensitive to mental challenge tasks that provoke acute psychological stress. Further research is needed to replicate the observed psychological stress-induced changes in neutrophil function.