Specificity of antigliadin antibody in celiac disease.

Celiac disease is activated in genetically susceptible individuals by the dietary ingestion of wheat gluten and similar proteins in other grains. Gliadins are a complex mixture of proteins that contain at least 40 different components in a single variety of wheat. We have purified the four major electrophoretic fractions of wheat gliadin and examined the specificity of antigliadin antibody for those fractions by radioimmunoassay in 30 patients with celiac disease and 30 matched controls. All patients had been on a gluten-free diet for more than 18 mo and were clinically asymptomatic at the time of study. Seventeen of 30 patients had increased antibody levels to one or more of the gliadin fractions. Twelve of 17 patients had elevated antibody to A or 6D alpha-gliadin, 9 of 17 to beta-gliadin, 10 of 17 to gamma-gliadin, and 8 of 17 to omega-gliadin. Of the 17 subjects, 5 had increased antigliadin antibody levels to one gliadin fraction only, whereas 12 had increased levels to two or more fractions. Of the 17 patients with increased antibody titers, 16 had the G2m(n) immunoglobulin heavy chain allotype marker and 14 had the serologic HLA specificities-B8 or-DR3, or both. Definition of the wheat gliadin fractions and specific gliadin peptides that can activate celiac disease remains an open question. These data indicate that antigliadin antibody in the serum of asymptomatic patients with celiac disease who are maintained on a gluten-free diet can be directed against one or a multiple of gliadin fractions.