Immunity, inflammatory and psychophysiological stress response during a competition of professional rugby union

Neopterin, cortisol and immunoglobulin A were measured to determine what effect a professional rugby competition has on the immunity, inflammatory and psychophysiological stress response. Urine and saliva were collected from 37 professional players at regular intervals throughout a 20 week professional competition. Total neopterin, cortisol and secretory immunoglobulin A were analysed using enzyme linked immunosorbant assay (ELISA) and high performance liquid chromatography (HPLC). All markers did not change significantly when analysed as a group during the course of the season compared to baseline (p>0.05), although long-distance travel had a minor effect on cortisol and secretory immunoglobulin A concentrations (p<0.05). More importantly, a large inter-individual variation for all markers was observed (p<0.001). These results indicate this competition of professional rugby does not cause significant changes in psychophysiological stress. Some players however, may become more susceptible to fatigue and infection during the course of a season as a result of suppressed immunity and sustained activation of the inflammatory response.