Psychological stress and neutrophil function

Suliman Khanfer, Riyad (2011). Psychological stress and neutrophil function. University of Birmingham. Ph.D.

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Abstract

Little is known about neutrophil function, an important component of innate immunity, in relation to psychosocial factors. This thesis investigated the effect of acute and chronic psychological stressors on human neutrophil function among young and older adults. The first two studies examined the effects of an acute laboratory psychological stress task on neutrophil function in young and older adults, respectively. Blood samples to determine neutrophil function were taken at resting baseline, during acute stress and during recovery. In the first study (N=40), there was an acute increase in phagocytic ability and a reduction of superoxide production associated with the stress task relative to baseline. In study two (N =17), there was a significant reduction of neutrophil superoxide production associated with the stress task. Study three (N=48) examined the effect of chronic stress, a recent bereavement (<2 months), on neutrophil function in elders. Cortisol and dehydroepiandrosterone-sulphate (DHEAS) levels were determined in serum to assess potential mechanisms. Superoxide production was significantly reduced among the bereaved group when challenged with E. Coli; also, the bereaved had a significantly higher cortisol:DHEAS ratio compared to controls. Overall, this thesis shows that human neutrophil function is sensitive to both acute and chronic psychological stress exposures; however, more research is needed to determine the specific underlying mechanisms behind the observed alterations.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):