SIgA and Upper Respiratory Syndrome During a College Cross Country Season

It has been almost 40 years since Tomasi and colleagues reported their groundbreaking work on the link between exercise and upper respiratory tract infections (URTI). This rightly inspired a revival of study on exercise and infection [38]. Mackinnon and colleagues [20] furthered this impetus for more study with their finding connecting decreased secretion rates of salivary IgA (SIgA) to increased URTI [20]. This finding, in turn, has led to decades of study and thousands of publications examining the relationship between SIgA and URTI in athletes. For over 30 years now, studies examining the effects of exercise, URTI and SIgA have continued across multiple populations. The high level of interest in this field stems mainly from the fact that URTI results in decreased performance; further, it can not only interrupt training, but if it occurs at the time of an Olympic event, can potentially undo years of training [34]. The majority of studies record symptoms as URTI, but this label is problematic for a variety of reasons. First, pathological identifications of organisms are rarely made; more importantly, symptoms can be caused by a number of non-pathologies such as asthma, allergies or drying of airways [16]. There is tremendous confusion as to the exact cause of symptoms that athletes report. Therefore, unless an actual URTI diagnosis is made by a physician, the position of the International Society of Exercise Immunology is that researchers use the term “upper respiratory symptoms” (URS) [40]. Hence, the term URS will be used throughout this paper. The extensive body of research that examines the relationship between exercise, SIgA and URS in athletic populations has led to the belief that the most useful outcome measure from a clinical viewpoint is URS [24], and the immune variable most closely associated with URS is SIgA [16]. The mucosal immune system repreSIgA and Upper Respiratory Syndrome During a College Cross Country Season