CD79A and selective IgA deficiency disease: Given the relatively high prevalence of IgA deficiency in relation to other autoimmune diseases in patients with CD, evaluation of this deficiency and use of CD -specific IgA autoantibodies against the enzyme tissue transglutaminase (tTG IgA) is recommended by current North American Society for Pediatric Gastroenterology, Hepatology and Nutrition guidelines [14].