CD79A and Recurrent upper respiratory tract infections: Salivary immunoglobulin A (s-IgA), secreted by oral epithelial cells, is the predominant antibody in mucosal fluid and plays an important role in neutralizing virus and bacteria during oral and suppressing upper respiratory tract infections (Lamm et al.1995; Marcotte and Lavoie 1998; Woof and Mestecky 2005).