IgA assessment has attractive advantages over WBC counts as it can be measured in saliva, a non-invasive sample with better applicability in the context of sports practice, and lower salivary IgA (sIgA) levels have been linked to higher incidence of upper respiratory tract infections (URTI) in athletes (Neville et al., 2008; Mortatti et al., 2012). This evidence concerns the gene CD79A and Recurrent upper respiratory tract infections.