Objective Evaluate in patients with celiac disease the tolerance of prolonged consumption of small amounts of gliadin contained in products containing wheat starch. Design Open 1-year trial of the addition of wheat starch to a gluten-free diet in a cohort of adult patients with biopsy-proven celiac disease who had never consumed wheat starch. The control group consisted of patients with celiac disease who tolerated wheat starch.

Subjects Seventeen patients with celiac disease and 14 control patients, all diagnosed according to criteria of the European Society of Pediatric Gastroenterology and Nutrition, were recruited from the Canadian Celiac Association and the Quebec Celiac Foundation.

Setting The study was conducted in the outpatient clinic of the Gastroenterology and Nutrition Service of Ste Justine Hospital, Montreal, Quebec, Canada. Interventions Patients were asked to consume four to six portions daily of a wheat starch-containing product, mainly bread, for up to 1 year.

Main outcome measures The gliadin content of the wheat starch product used in this trial was quantified by enzyme linked irnmunosorbent assay. Patient outcome measures included symptoms, nutritional parameters (anthropometric data, complete blood count, serum folate and iron levels), and immunologic parameters (antigliadin antibody and antiendomysium antibody titers).

Results A quantifiable amount of immunoreactive gliadin (0.75mg/100g) was found in the wheat starch. The majority of the patients with celiac disease (11 of 17) who had never consumed wheat starch previously developed symptoms, which resolved within weeks of discontinuing the product. Relapse of skin lesions was seen in two of three patients with coexisting dermatitis herpetiformis. No weight loss or biochemical changes were observed. Despite the presence of symptoms, antigliadin antibody and antiendomysium antibody determinations were not useful to detect the clinical intolerance.

Applications The innocuousness of the long-term ingestion of “gluten-free” products containing wheat starch is still unproven, and prolonged use of such products by patients with celiac disease cannot be recommended.