Antibody response against wheat, rye, barley, oats and corn: comparison between gluten-sensitive patients and monoclonal antigliadin antibodies.

The antibody response of patients with gluten-sensitive enteropathy and dermatitis herpetiformis against alcohol-soluble prolamines of wheat, rye, barley, oats and corn assessed by immunoblotting was compared to the staining patterns produced by monoclonal antigliadin antibodies. Both monoclonal antibodies (MAbs) and patient serum reacted with wheat, rye, barley and oats, the patient serum showing individual variation both in IgA and IgG stainings. A broad reactivity with polypeptides from 30 to 68 kD was, however, typical for patient serum and comparable to the reactivity of two broadly reacting antigliadin MAbs. This kind of broad reactivity of the MAb may suggest that it binds to glutamine-repeating sequences of highly homologous gliadin polypeptides. Glutamine- and proline-containing motifs Pro-Ser-Gln-Gln and Gln-Gln-Gln-Pro are also included in the peptides toxic to the celiac small intestinal mucosa. Our study indicates that the humoral response of the patients may detect similar structures, in oat prolamines as well. Patient serum and one of the MAbs also reacted with a 22-kD polypeptide of corn extract. The meaning of this reactivity is not known, and further characterization of the antigenic epitopes of different cereals will be important.