title: Thymic function-related markers within the thymus and peripheral blood: Are they comparable?
abstract: The thymus involutes with age and its functionality has traditionally been assumed to be limited early in life. However, some studies have demonstrated that thymic function persists in adults. In humans, since it is difficult to obtain thymic samples from healthy individuals, indirect parameters have been used to study the thymic function. The aim of this study was to compare thymic function parameters within both the thymus and peripheral blood mononuclear cells from thirty-three patients who underwent cardiac surgery, as well as to relate these parameters with aging. The proportion of peripheral naïve T cells and intrathymic T cell differentiation stages, as well as peripheral and intrathymic TREC levels were analysed. We demonstrated that thymopoyesis persists in the healthy elderly since all T cell differentiation stages were found within the thymus. Among the studied parameters, peripheral TREC levels are found to be a good thymic function marker since they correlated with age. In healthy individuals, peripheral TREC levels are a good reflect of thymic function as demonstrated by their correlation with intrathymic TREC values.
authors.affiliation: AIDS and Hepatitis Study Group, Internal Medicine, Hospital Universitario Virgen del Rocio, Seville, Spain.
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Arellano
authors.forename: Antonio
authors.initials: A
authors.lastname: Ordóñez
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Ruiz-Mateos
authors.forename: Santiago R
authors.initials: SR
authors.lastname: Leal-Noval
authors.forename: Sonia
authors.initials: S
authors.lastname: Molina-Pinelo
authors.forename: Ana
authors.initials: A
authors.lastname: Hernández
authors.forename: Alejandro
authors.initials: A
authors.lastname: Vallejo
authors.forename: Rafael
authors.initials: R
authors.lastname: Hinojosa
authors.forename: Manuel
authors.initials: M
authors.lastname: Leal
mesh_terms: D000368:Aged; D000375:Aging; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry; D002454:Cell Differentiation; D015329:Gene Rearrangement, T-Lymphocyte / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010641:Phenotype; D013950:Thymus Gland / Q000737:chemistry* / Q000166:cytology / Q000502:physiology*
chemical_list: D015415:Biomarkers