title: An analysis of T lymphocyte subpopulations in patients with Alzheimer's disease.
abstract: The relative proportions of regulatory T lymphocyte subpopulations and T lymphocyte proliferative responses to the mitogen phytohemagglutinin (PHA) were studied in 30 patients with clinically apparent Alzheimer's disease (mean age = 71.5). Comparisons were made with 30 age-matched, nondemented healthy controls (mean age = 68.8) and with 20 younger, normal adult controls (mean age = 27.5). The relative percentages of total peripheral T lymphocytes, T helper/inducer lymphocytes (Th), and T suppressor/cytotoxic lymphocytes (Ts) were similar between the Alzheimer patient group and the age-matched controls. However, when the two older groups were compared with the young adult controls, a significant decrease was seen in the percentage of Ts cells, with a concomitant increase in the ratio of Th:Ts. Lymphocyte proliferative responses to PHA were similar in the Alzheimer patients and their age-matched controls; however, when compared with the young adult controls, a significant decrease in responsiveness for both older groups was observed. These results confirm decreases in certain immune indices with aging, but suggest that there are no changes in T lymphocyte subsets or in lymphocyte proliferation, which are unique to Alzheimer's disease.
authors.forename: M S
authors.initials: MS
authors.lastname: Leffell
authors.forename: L
authors.initials: L
authors.lastname: Lumsden
authors.forename: W A
authors.initials: WA
authors.lastname: Steiger
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000544:Alzheimer Disease / Q000276:immunology*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology; D050378:T-Lymphocytes, Regulatory / Q000502:physiology
chemical_list: D010835:Phytohemagglutinins