Oats do not induce systemic or mucosal autoantibody response in children with coeliac disease

A gluten-free diet omitting wheat, rye, and barley is the only effective treatment for coeliac disease. The necessity of excluding oats from the diet has remained controversial. We studied the toxicity of oats in children with coeliac disease during a 2-year follow-up by investigating jejunal transglutaminase 2 (TG2)-targeted IgA-class autoantibody deposits, a potentially more sensitive disease marker than serum antibodies or conventional histology.

Twenty-three coeliac children in remission were randomized to undergo oat or gluten challenge with wheat, rye, barley, and oats. When jejunal histological relapse was evident after gluten challenge, patients excluded wheat, rye, and barley but continued with oats. Mucosal morphology and TG2-targeted autoantibody deposits were studied in jejunal biopsies taken at baseline and after 6 and 24 months. Furthermore, serum IgA-class TG2 antibodies were measured.

At baseline, serum TG2 antibodies were negative in all 23 patients, but 7 of them had minor mucosal deposits. In the oats group, there was no significant change in the intensity of the deposits within 2 years. In contrast, during the gluten challenge, the intensity of the deposits clearly increased and decreased again when wheat, rye, and barley were excluded but consumption of oats was continued; this was in line with serum autoantibodies. The intensity of the mucosal deposits correlated well with both villous morphology and serum autoantibody levels.

Consumption of oats does not induce TG2 autoantibody production at mucosal level in children with coeliac disease. Measurement of small-intestinal mucosal autoantibody deposits is suitable for monitoring treatment in coeliac patients.