Depression in caregivers of demented patients is associated with altered immunity: impaired proliferative capacity, increased CD8+, and a decline in lymphocytes with surface signal transduction molecules (CD38+) and a cytotoxicity marker (CD56+ CD8+).
Changes in relevant immune parameters, including function, were found to be associated with depression in elderly caregiver wives of demented patients. We studied the relationship between immune cell phenotype and T cell proliferative capacity of such caregivers to levels of stress and depression over the course of a support group intervention. The data indicate the strongest association between depression (of all stress parameters) and impaired T cell proliferative capacity. Depression was also most strongly (of stress parameters) associated with a shift in T cell populations with an increase in CD8+ T cells, and a reduced percentage of CD38+ cells in both CD8+ and CD4+ T cell populations. Since CD38 is a signal transduction factor, it was interesting that a decreased percentage of CD38+ cells correlated with impaired T cell function (proliferation). Another significant difference was the reduction in natural killer (NK) cells as well as the percentage of the CD56+ component of the CD8+ population. This latter subset is important in MHC-unrestricted cytotoxicity, and has been found expanded in healthy centenarians. This study shows that both chronic stress, and depression in particular, and age have deleterious effects on T cells, and together could significantly contribute to the higher risk of disease and mortality associated with being a caregiver of a demented individual.
Castle
S
S
Geriatric Research Education and Clinical Centre, VAMC West Los Angeles CA 90073, USA.
Wilkins
S
S
Heck
E
E
Tanzy
K
K
Fahey
J
J
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000367:Age Factors; D000368:Aged; D015703:Antigens, CD / Q000032:analysis*; D000943:Antigens, Differentiation / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D019002:CD56 Antigen; D016827:CD8 Antigens / Q000032:analysis*; D002455:Cell Division; D003863:Depression / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D008562:Membrane Glycoproteins; D009699:N-Glycosyl Hydrolases / Q000032:analysis*; D011369:Professional-Patient Relations; D013315:Stress, Psychological / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D016827:CD8 Antigens; D008562:Membrane Glycoproteins; D009699:N-Glycosyl Hydrolases; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1