title: Reduced thymic output in elite athletes.
abstract: Athletes undergoing intensive training schedules have chronic exposure to stress-induced hormones such as cortisol that can depress immune function. We compared the circulating levels of T cell receptor excision circles (TREC), a marker of recent thymic emigrants, as well as the levels of naïve and memory subsets in a group of elite endurance athletes and in controls. The athletes showed a reduction in absolute numbers of naïve T cells, particularly in CD4 T cells. In contrast, memory cells were increased. TREC levels in the athletes were significantly reduced compared to age-matched controls. Such changes resemble premature ageing of the T cell component of the immune system. Since thymic production of T cells naturally decline with age, these results raise the concern that prolonging high intensity exercise into the 4th decade of life may have deleterious consequences for athletes' health.
authors.affiliation: Anthony Nolan Research Institute, The Royal Free Hospital, London, United Kingdom.
authors.forename: Adria
authors.initials: A
authors.lastname: Prieto-Hinojosa
authors.affiliation: Anthony Nolan Research Institute, The Royal Free Hospital, London, United Kingdom.
authors.forename: Andrea
authors.initials: A
authors.lastname: Knight
authors.affiliation: School of Life Sciences, University of Edinburgh, United Kingdom.
authors.forename: Claude
authors.initials: C
authors.lastname: Compton
authors.affiliation: School of Sport and Exercise Science, Loughborough University, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Gleeson
authors.affiliation: Anthony Nolan Research Institute, The Royal Free Hospital, London, United Kingdom; MRC Centre for Regenerative Medicine, Edinburgh Royal Infirmary, United Kingdom. Electronic address: paul.travers@ed.ac.uk.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Travers
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D015444:Exercise / Q000502:physiology*; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*; D055815:Young Adult
keywords: Exercise immunology; Naïve T cell; Thymus