title: Increased Circulating Anti-inflammatory Cells in Marathon-trained Runners.
abstract: Exercise training can alter immune function. Marathon training has been associated with an increased susceptibility to infectious diseases and an increased activity of inflammatory-based diseases, but the precise mechanisms are unknown. The purpose of this study was to compare levels of circulating CD4+  T cell subsets in the periphery of marathon-trained runners and matched non-marathon controls. 19 recreational marathoners that were 4 weeks from running a marathon and 19 demographically-matched healthy control subjects had the percentage of CD4+ T cell subpopulations (T helper 1, T helper 2, T helper 1/T helper 2 ratio, regulatory T cells, CD4+ IL10+, and CD4+ TGFβ+ (Transforming Growth Factor-beta) measured by flow cytometry. Marathon-trained runners had significantly less T helper 1 and regulatory T cells and significantly more T helper 2, CD4+ IL10+, and TGFβ+ cells than the control subjects. The alterations in the percentage of T helper 1 and T helper 2 cells led to a significantly lower T helper 1/T helper 2 ratio in the marathon-trained runners. These data suggest that endurance-based training can increase the number of anti-inflammatory cells. This may be a potential mechanism for the increased incidence of both infectious and inflammatory diseases observed in endurance athletes.
authors.affiliation: Department of Medicine, University of Mississippi Medical Center, Jackson, United States.
authors.forename: K
authors.initials: K
authors.lastname: Rehm
authors.affiliation: Center for Biostatistics, University Of Mississippi Medical Center, Jackson, United States.
authors.forename: I
authors.initials: I
authors.lastname: Sunesara
authors.affiliation: Department of Medicine, University of Mississippi Medical Center, Jackson, United States.
authors.forename: G D
authors.initials: GD
authors.lastname: Marshall
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D003430:Cross-Sectional Studies; D004198:Disease Susceptibility / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism