title: Distinct categories of immunologic changes in frail elderly.
abstract: Immune changes and their relationships in a frail elderly population (N=116, age 70-103, median 86 years) were defined in comparison to a healthy younger group. Previous immune studies in the elderly have generally focused on one or few parameters without correlation analyses. Furthermore, the study populations have been active elderly in relatively small numbers. A total of 33 immune parameters representing many aspects of the immune system were quantified. Most changes in the frail elderly were parallel to those reported in active elderly. A classification tree analysis revealed that increased plasma activation markers (neopterin and sTNF-R) and increased CD28 expression on CD8 T cells and proliferative response separated the aged and control populations. Statistical procedures utilizing principal components analyses, partial correlations and exploratory factor analyses all indicated that immunologic parameters in frail elderly are grouped in three major clusters of immunologic results. These involved (a) increased plasma levels of neopterin and sTNF receptor indicating elevated IFNgamma and TNF cytokine activity; (b) increased proportion of mature (CD45RO) versus naïve (CD45RA) T cells; and (c) a diverse group of related changes including impaired proliferative response, reduced T cells, CD28 and CD25 expression, B cell percentage and lower CD4:CD8 ratios and increased HLA-DR expression. These findings emphasize that several different groups of immune parameters but not 33 independent immune changes, occurred in the aged population.
authors.affiliation: Center for Interdisciplinary Research in Immunology and Disease (CIRID) and the UCLA AIDS Institute and Department of Microbiology and Immunology, UCLA School of Medicine, 90095-1747, Los Angeles, CA, USA. jlfahey@mednet.ucla.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Fahey
authors.forename: J F
authors.initials: JF
authors.lastname: Schnelle
authors.forename: J
authors.initials: J
authors.lastname: Boscardin
authors.forename: J K
authors.initials: JK
authors.lastname: Thomas
authors.forename: M E
authors.initials: ME
authors.lastname: Gorre
authors.forename: N
authors.initials: N
authors.lastname: Aziz
authors.forename: H
authors.initials: H
authors.lastname: Sadeghi
authors.forename: P
authors.initials: P
authors.lastname: Nishanian
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000032:analysis; D018106:CD28 Antigens / Q000032:analysis; D002455:Cell Division; D016207:Cytokines / Q000097:blood; D005260:Female; D016330:Frail Elderly; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007107:Immune System / Q000473:pathology / Q000503:physiopathology*; D007156:Immunologic Memory / Q000502:physiology; D016131:Lymphocyte Subsets / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D009244:NAD+ Nucleosidase / Q000032:analysis; D010641:Phenotype; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D018106:CD28 Antigens; D016207:Cytokines; D006684:HLA-DR Antigens; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1