Differential Immune Cell Chemotaxis Responses to Acute... : Psychosomatic Medicine (original) (raw)

Original Articles

Differential Immune Cell Chemotaxis Responses to Acute Psychological Stress in Alzheimer Caregivers Compared to Non-caregiver Controls

Redwine, Laura PhD; Mills, Paul J. PhD; Sada, Merna BS; Dimsdale, Joel MD; Patterson, Thomas PhD; Grant, Igor MD

From the Department of Psychiatry, University of California, San Diego.

Received for publication February 4, 2004; revision received May 12, 2004.

Address correspondence and reprint requests to Laura Redwine, PhD, VA San Diego Healthcare System, 9–151, 3350 La Jolla Village Dr., La Jolla, CA 92161. E-mail: [email protected]

This work was supported in part by award 5R01AG015301 to 14 from the National Institutes of Health, National Institute on Aging.

Abstract

Objective:

Caregiving for a spouse with Alzheimer’s disease is associated with alterations in various immune cell responses. Chemotaxis of immune cells to chemokines is an important factor involved in lymphocyte migration, which plays an essential role in inflammatory responses to infection and may also be involved in atherogenesis. However, the effects of chronic stress on chemotaxis have not been investigated. The objective of this study was to examine lymphocyte chemotaxis to chemokines, stromal cell-derived factor-1 (SDF-1), N-formyl-methionyl-leucyl-phenylalanine (FMLP), and a beta-adrenergic agonist, isoproteronol (ISO), in response to an acute stressor in Alzheimer’s caregivers. Correlations between immune cell chemotaxis and epinephrine and norepinephrine levels were also examined.

Methods:

Caregivers (n = 18) and noncaregiver controls (n = 9) completed a public speaking task. Blood was drawn before and immediately after the task for changes in chemotaxis to FMLP, SDF-1, and ISO, and for epinephrine and norepinephrine levels.

Results:

Caregivers had reduced chemotaxis to FMLP, SDF-1, and ISO in response to the speech task, compared with non-caregivers. Also, the direction of the correlations between chemotaxis to FMLP, SDF-1, and ISO and epinephrine levels differed between groups.

Conclusions:

These findings suggest that immune cells released into circulation in response to acute stress are altered in caregivers. Group differences in immune responses may be due to sympathetically mediated alterations, which may have implications for caregivers’ ability to successfully mount viable immune responses, as well as, atherogenesis.

AD = Alzheimer’s disease;

ANOVA = analysis of variance;

FMLP = N-formyl-methionyl-leucyl-phenylalanine;

ISO = isoproterenol;

PBMC = peripheral blood mononuclear cell;

SAM = sympathetic-adrenal medullary;

SDF-1 = stromal cell-derived factor-1;

UCSD = University of California, San Diego.