Antibodies to oat prolamines (avenins) in children with coeliac disease

Background: The use of oats in a gluten-free diet for children with coeliac disease is presently under investigation. In this study we measured the content of antibodies to oat prolamines (avenin) in sera from coeliac children and reference children. Methods: Crude avenin was prepared by extraction with ethanol and salt-solution and used as antigen in a three-step ELISA. Sera from 81 children, including 34 children with verified coeliac disease, were analysed for both IgA and IgG antibodies to avenin and gliadin. Sera were also incubated with gliadin before exposure to avenin, and vice versa, to assess a possible cross-reaction between the species. Keyhole limpet hemocyanin (KLH) was used as a negative control. Results: Children with coeliac disease on a normal diet had significantly higher levels of antibodies to avenin, both IgG and IgA, than reference children (P < 0.001) and the levels correlated positively with gliadin antibodies, especially of IgA-type (r = 0.798). Both anti-avenin and anti-gliadin antibodies were only absorbed by the corresponding protein. Conclusions: Children with coeliac disease have antibodies to oat proteins at significantly higher levels than reference children. The absorption test did not indicate a cross-reactivity between the prolamines of wheat and oats. The method will be employed for repeated sampling of anti-avenin antibodies during a prospective interventional study with a gluten-free diet supplemented with oats.