Lack of cellular and humoral immunological responses to oats in adults with coeliac disease

Abstract

Objective: Recent research suggests that oats do not harm intestinal villi in adults with coeliac disease. As the immunological effects of oats have not been examined in detail, it was decided to compare the immunological responses of a gluten free diet including oats with those of a conventional gluten free diet.

Design: A randomised controlled intervention study over 6-12 months.

Subjects: Forty adults with newly diagnosed coeliac disease and 52 with coeliac disease in remission were examined.

Intervention: The effects of a gluten free diet including oats and a conventional gluten free diet were compared.

Main outcome measures: Serum levels of gliadin and reticulin antibodies as well as numbers of intraepithelial lymphocytes (IELs) in intestinal mucosa were examined before and after the intervention.

Results: The rate of disappearance of gliadin and reticulin antibodies did not differ between the diet groups in patients with newly diagnosed coeliac disease. Oats also had no effect on gliadin or reticulin antibody levels in the patients with remission. The number of IELs decreased similarly regardless of the diet of newly diagnosed patients, and no increase in the number of IELs was found in the patients in remission with or without oats.

Conclusions: These results strengthen the view that adult patients with coeliac disease can consume moderate amounts of oats without adverse immunological effects.

Figure 1

Titres of IgA (A) and IgG (B) gliadin antibodies and IgA (C) reticulin antibodies in the oat and control groups of newly diagnosed coeliac patients determined at baseline, and at one, three, six, and 12 months after the institution of the diet. There were no significant differences between the groups (p>0.10; Fisher test). Within group changes were significant for anti-gliadin IgA (p = 0.016 and p = 0.002) and for reticulin antibodies (p = 0.001 and p = 0.002) in both groups, and for anti-gliadin IgG in the control group (p = 0.031) (McNemar test). Normal levels of anti-gliadin IgA are <0.5 EU/ml and of anti-gliadin IgG <20 EU/ml; normal values of IgA reticulin antibody are titres <5. The horizontal line in (A) and (B) represent the upper cut off limit of normal values of IgA and IgG gliadin antibodies respectively. At 12 months, three patients (one in the oat consuming group and two in the control group) had positive (>0.5) anti-gliadin IgA. All patients had normal anti-gliadin IgG levels. At 12 months, three patients (one in the oat consuming group and two in the control group) had anti-reticulin IgA levels of 5-50 EU/ml.