MEASUREMENT OF GLUTEN USING A MONOCLONAL-ANTIBODY TO A CELIAC TOXIC PEPTIDE OF A-GLIADIN

Background-Future European Community regulations will require a sensit ive and specific assay for measurement of coeliac toxic gluten protein s in foods marketed as gluten-free. To avoid spurious cross reactions with non-toxic proteins, specific antibodies and target antigens are r equired. A synthetic 19 amino acid peptide of A gliadin has been shown to cause deterioration in the morphology of small intestinal biopsy s pecimens of coeliac patients in remission. Aims-To develop an assay fo r detection of gluten in foods, based on measurement of a known toxic peptide, Methods-A monoclonal antibody raised against the toxic A glia din peptide, with a polyclonal anti-unfractionated gliadin capture ant ibody, was used to develop a double sandwich enzyme linked immunosorbe nt assay (ELISA) for the measurement of gluten in foods. Results-Stand ard curves for gliadin and for rye, barley, and oat prolamins were pro duced. The sensitivity of the assay was 4 ng/ml of gliadin, 500 ng/ml for rye prolamins, and 1000 ng/ml for oat and barley prolamins. The as say could detect gluten in cooked foods, although at reduced sensitivi ty, Prolamins from coeliac non-toxic rice, maize, millet, and sorghum did not cross react in the assay. A variety of commercially available gluten-free foods were analysed; small quantities of gluten were detec ted in some products. Conclusion-The assay may form the basis of a sen sitive method for measurement of gluten in foods for consumption by pa tients with coeliac disease.