title: Variation rhythms of lymphocyte subsets during healthy aging.
abstract: Immunological alterations associated with aging (immunosenescence) do not represent a simple unidirectional decline in all functions but develop as a complex remodeling of the immune system, involving multiple reorganization and developmentally regulated changes. In general, most data available about aging were obtained at particular age intervals and most of them come from Caucasian individuals from either Europe or the United States. Here, we report the frequencies of major lymphocyte subsets in healthy Brazilian individuals from 2 distinct geographic regions (Southeast and South) at several age intervals spanning a lifetime period (0-86 years). Overall, we demonstrated that changes in the frequencies of cells related to both innate and adaptive immunity clearly occur with aging in these individuals. These changes were not progressive and equally steady for all cell populations tested but instead showed an oscillatory or rhythmic behavior that was distinctive of each population at different age intervals. We also observed that abrupt changes in the frequencies of immune cells may occur in healthy individuals over 75 years old, suggesting there is an impaired flexibility of the immune system at late stages of life to sustain homeostasis via immune mechanisms. We presented reference ranges for healthy Brazilian individuals at all ages. The knowledge of these parameters in further detail will allow interventions to optimize immune function in advanced age and to improve the quality of life in the elderly.
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. afaria@icb.ufmg.br
authors.forename: Ana Maria Caetano
authors.initials: AM
authors.lastname: Faria
authors.forename: Sara Monteiro
authors.initials: SM
authors.lastname: de Moraes
authors.forename: Ludmila Helene Ferreira
authors.initials: LH
authors.lastname: de Freitas
authors.forename: Elaine
authors.initials: E
authors.lastname: Speziali
authors.forename: Taciana Figueiredo
authors.initials: TF
authors.lastname: Soares
authors.forename: Suzane Pretti
authors.initials: SP
authors.lastname: Figueiredo-Neves
authors.forename: Danielle Marquete
authors.initials: DM
authors.lastname: Vitelli-Avelar
authors.forename: Marina Angela
authors.initials: MA
authors.lastname: Martins
authors.forename: Kátia Valéria Bastos Dias
authors.initials: KV
authors.lastname: Barbosa
authors.forename: Eric Basseti
authors.initials: EB
authors.lastname: Soares
authors.forename: Renato
authors.initials: R
authors.lastname: Sathler-Avelar
authors.forename: Vanessa
authors.initials: V
authors.lastname: Peruhype-Magalhães
authors.forename: Glenda Meira
authors.initials: GM
authors.lastname: Cardoso
authors.forename: Fabiano
authors.initials: F
authors.lastname: Comin
authors.forename: Rosângela
authors.initials: R
authors.lastname: Teixeira
authors.forename: Silvana Maria
authors.initials: SM
authors.lastname: Elói-Santos
authors.forename: Dulciene Maria Magalhães
authors.initials: DM
authors.lastname: Queiroz
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Corrêa-Oliveira
authors.forename: Moisés Evandro
authors.initials: ME
authors.lastname: Bauer
authors.forename: Andréa
authors.initials: A
authors.lastname: Teixeira-Carvalho
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000276:immunology*; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007121:Immunocompetence; D016130:Immunophenotyping; D007223:Infant; D007231:Infant, Newborn; D007694:Killer Cells, Natural; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000166:cytology*; D008297:Male; D012016:Reference Values; D050378:T-Lymphocytes, Regulatory; D055815:Young Adult