Gluten Quantification of Foods via the Immunodominant Gliadin Epitope

Abstract

Coeliac disease (CD) is an immune mediated condition involving dietary gluten, found in wheat, rye, and barley; avoiding them is the only treatment. We generated a mAb to the immunodominant gliadin epitope alpha-2-gli-57-75 and developed assays to quantify gluten in foods, comparing the results with those from the R5 assay. Competition assays were developed using native gliadin as the competing and coating antigen. Results were compared with those from the Ingenesa Ingezim Gluten ® kit. The mAb recognized prolamins from wheat, spelt, rye and barley. A competition assay that detected gliadin at 0.027ppm in a foodstuff revealed gliadin contamination of several foods labelled gluten-free. Purified wheat starch, used as wheat flour substitute to generate gluten-free foods, contains quantifiable amounts of the immunodominant epitope. The assay is sufficiently sensitive to assess the suitability of foods for coeliac patients and could be used as an alternative to the R5.