The rate of IgA-AAA positivity by IFI and ELISA in histologically proven celiac disease patients, were 5.5% and 25% patients in IIIA, 27.5% and 34.4% patients in IIIB, 78.8% and 75% in IIIC patients, respectively: showing an high sensitivity in predicting severe intestinal damage. The gene discussed is CD79A; the disease is celiac disease.