Changes in lymphocyte and neutrophil function induced by a marathon race

The aim of this study was to investigate the changes in lymphocyte and neutrophil selected functions before and after a marathon race. Fifteen professional athletes were recruited, and the following parameters were measured: plasma concentrations of IL-1ra, IL-6, IL-8, IL-10, TNF-α and C-reactive protein (CRP); neutrophil phagocytic capacity; cytokine production by neutrophils and lymphocytes and signs of neutrophil and lymphocyte death. The marathon race had no effect on CRP levels, but plasma concentrations of IL-6 and IL-1ra were increased. Although no effect was observed on the production of IL-6, IL1-ra, TNF-α, IL-1β and IL-8 by unstimulated or stimulated neutrophils, a decrease in neutrophil phagocytic activity was observed immediately following the marathon. A high percentage of neutrophils undergoing apoptosis was observed due to the intense training regimen, whereas the percentages of apoptotic neutrophils were reduced after the race. The production of IL-2, TNF-α, IL-1β and IL-10 by lymphocytes was decreased by 50%-80%, and the percentage of apoptotic and necrotic lymphocytes was increased by 42% and fourfold, respectively, as a result of the race. In conclusion, the increase in plasma levels of IL-6, IL-8, IL-1ra and IL-10 after the race was not due to the production of the cytokines by neutrophils or lymphocytes. In fact, the marathon led to a decrease in lymphocyte and neutrophil function, and the diminished function was more pronounced in lymphocytes, indicating an impairment in acquired immunity.