Reactivity of gliadin and lectins with celiac intestinal mucosa

The binding patterns of gliadin and selected lectins to jejunal biopsy specimens obtained from children with total villous atrophy during active celiac disease (CD; 19 patients) and in remission (16 patients) were examined by light microscopy. Three categories of carbohydrate-specific lectins were chosen for the study: those recognizing mannose/glucose residues, those recognizing N-acetyl-glucosamine/glucose (glcNAc/glc) residues, and those recognizing N-acetylgalactosamine/galactose (galNAc/gal) residues. The galNAc/gal lectins, with the exception of phaseolus vulgaris agglutinin variants, presented a typical staining of the luminal surface of the jejunal mucosa obtained from CD patients. However, these lectins displayed no reactivity to jejunal sections of CD patients in remission or control biopsies that included healthy children (25 children) and patients suffering from cow milk protein allergy (10 children). The glcNAc/glc lectin showed a strong preferential recognition of CD jejunal tissue but also bound with less intensity to specimens from patients with cow milk allergies and healthy children. Unlike other galNAc/gal lectins, phaseolus vulgaris agglutinin variants were indistinguishable in their binding patterns to the mucosa of control groups and CD patients in remission and failed to react to CD biopsies. The mannose/glc lectins were not distinctive in their binding patterns. In all cases, lectin binding was specifically inhibited by the lectins' competitive saccharides. Atypical of lectin binding patterns, gliadin reactivity was restricted to intracellular areas of enterocytes and was unique to active CD mucosa. The distinctive binding patterns of lectins and gliadin provide a diagnostic tool to distinguish patients with active CD from those in remission or patients with other intestinal disorders.(ABSTRACT TRUNCATED AT 250 WORDS)