Mucosal digestion studies of whole gliadin fractions in coeliac disease.

Wheat gliadin was chromatographed on carboxymethyl cellulose and the major fractions (alpha-, beta- and gamma-gliadin) digested with pepsin, trypsin and pancreatin. The digests from each fraction were chromatographed on SP Sephadex and the fractions corresponding to the one previously shown to be toxic by oral feeding tests (fraction 9) were incubated with homogenates of small intestinal mucosa from children with coeliac disease in remission and from normal children. Electrophoretic patterns of the coeliac mucosal digests of fraction 9 from the alpha-, beta- and gamma-gliadin fractions all showed that appreciable amounts of undigested peptides were present in each of the three digests. In contrast, patterns of all digests prepared using normal mucosa showed only small amounts of undigested peptides. The results suggest that all three of these whole gliadin fractions contain substances which may be causative agents in coeliac disease.