Immunoreactivity of antibodies against transglutaminase-deamidated gliadins in adult celiac disease

Background: The significance of the presence of anti-gliadin antibodies in patients affected by celiac disease is still unclear. It is hypothesized that gliadin deamidation, catalysed by transglutaminase, plays a role in favoring the antigen presentation. Aim: To determine the immunoreactivity of anti-gliadin antibodies from untreated celiac patients to transglutaminase deamidated gliadins. Materials and methods: Gliadins from wheat flour underwent enzymatic digestion and were deamidated or cysteamine-transamidated by transglutaminase. Immunoreactivity of anti-gliadin antibodies from untreated adult celiac patients sera was evaluated by means of a competitive enzyme-linked immunosorbent assay (ELISA) method. Results: Gliadin deamidation increased antibodies immunoreactivity from 25% to 50% while cysteamine incorporation into the gliadin peptides resulted in an immunoreactivity decrease. Conclusions: Increased immunoreactivity of transglutaminase deamidated gliadins tested with anti-gliadin antibodies from untreated adult celiac patients supports the hypothesis of a pivotal role of gliadin deamidation in the pathomechanism of celiac disease.