Chronic stress and immunity in family caregivers of Alzheimerʼs disease victims.

Abstract

Although acute stress has been associated with transient immunosuppression, little is known about the immunologic consequences of chronic stress in humans. In order to investigate possible health-related consequences of a long-term stressor, we obtained blood samples for immunologic and nutritional analyses and psychologic data from 34 family caregivers of Alzheimer's disease (AD) victims and 34 sociodemographically matched comparison subjects. Family caregivers for AD victims were more distressed than comparison subjects without similar responsibilities. Greater impairment in the AD victim was associated with greater distress and loneliness in caregivers. Caregivers had significantly lower percentages of total T lymphocytes and helper T lymphocytes than did comparison subjects, as well as significantly lower helper-suppressor cell ratios; caregivers also had significantly higher antibody titers to Epstein-Barr virus than did comparison subjects, presumably reflecting poorer cellular immune system control of the latent virus in caregivers. The percentages of natural killer cells and suppressor T lymphocytes did not differ significantly. These data suggest that chronically stressed AD family caregivers do not show immunologic or psychologic adaptation to the level of their well-matched age peers.

Chronic stress modulates the virus-specific immune response to latent herpes simplex virus Type 1

“…No significant changes in antibody titers to poliovirus type-2 (a non-latent virus) and no evidence for a primary infection with EBV were observed (I 1). Consistent with these data from medical students, we found higher antibody titers to latent EBV in AD family caregivers than well-matched controls (2,15).…”

“…In previous studies involving caregivers of dementia patients, we found evidence of the modulation of latent EBV (2,15). These studies were extended to determine if the virus-specific immune response to latent HSV-1 infection was influenced by the stresses of caregiving with respect to three different markers related to the HSV-1 specific immune response: levels of neutralizing antibody, antibody titers to a total viral antigen preparation, and a memory proliferative T-cell response.…”

Antibody response to vaccination and psychosocial stress in humans: relationships and mechanisms

“…Stone and colleagues [29,30] required participants to swallow a capsule containing rabbit albumin each morning for [8][9][10][11][12] weeks, and then measured the daily specific sIgA response in saliva, as well as daily mood [29] and events [30]. This methodology allowed within-subject comparisons between antibody levels on high-stress and low-stress days.…”

“…People experiencing periods of chronic stress have been shown reductions in the number of helper T-lymphocytes [11][12][13], B-lymphocytes [14], and salivary concentrations of secretory immunoglobulin A (sIgA) [15][16][17][18], compared to controls. The clinical implications of reductions in these cell counts in healthy people, and within normal ranges, are unclear [19].…”

“…In vitro measures of immune function, such as lymphocyte proliferation to mitogen, have also been shown to be susceptible to stress-induced alterations [12,[20][21][22][23][24][25][26]. These functional assays give a better indication of immune status than the enumerative methods, as proliferation in response to antigen is a key component of the immune response.…”