Salivary immunoglobulin A response to a collegiate rugby game.

Transient fluctuations in immune function after heavy exercise have been linked to an increased incidence of infection in athletes. Several parameters of immunity, including salivary immunoglobulin A (IgA), are affected by heavy exercise in the laboratory setting. However, few observations have been made during true competition. We tested the hypothesis that salivary IgA levels will be decreased after a collegiate rugby game. Saliva samples obtained from 16 men's college rugby players before and after an 80-minute regulation rugby game were analyzed for total volume, IgA, total protein content, and osmolality. Salivary IgA was expressed relative to secretion rate (s-IgA), osmolality (IgA-Osm), and total protein (IgA-Pro). No significant pregame-postgame changes in salivary IgA were observed (s-IgA: -13%, IgA-Osm: -16%, IgA-Pro: +10%). These data indicate that strenuous physical activity, such as a competitive rugby game, does not affect IgA levels. More study on the immune response to athletic competition is needed.