- Usha Srinivasan, clinical registrara,
- Niamh Leonard, clinical registrarb,
- Eileen Jones, laboratory technicianb,
- Donald D Kasarda, research chemistc,
- Donald G Weir, regius professor of physicsd,
- Cliona O'Farrelly, director of research laboratorye,
- Conleth Feighery, associate professor of immunologya
- a Department of Immunology, St James's Hospital, Dublin 8, Republic of Ireland
- b Department of Histopathology, St James's Hospital, Dublin
- c US Department of Agriculture, Albany CA 94710, USA
- d Department of Gastroenterology, St James's Hospital and Trinity College, Dublin
- e Education and Research Centre, St Vincent's Hospital, Elm Park, Dublin
- Correspondence to: Professor Feighery.
- Accepted 18 July 1996
Coeliac disease is a gluten-sensitive disorder characterised by malabsorption and a typical histological lesion. Treatment with a strict gluten-free diet results in complete clinical and histological recovery. The conventional gluten-free diet used to treat coeliac disease proscribes oats cereal as well as wheat, barley, and rye.1 However, the issue of oats toxicity has not been conclusively resolved, and the prohibition of this important cereal deprives patients of a valuable source of fibre and nutrients. The aim of this study was to examine the clinical, histological, and immunological responses of adult patients with coeliac disease to challenge with oats.
Patients, methods, and results
Ten adult patients with coeliac disease in clinical and histological remission were recruited from the coeliac outpatient clinic in St James's Hospital, Dublin. Each patient consumed 50 g of oats (as porridge) daily for 12 weeks while maintaining a strict gluten-free diet. Patient compliance was recorded daily using diaries, and all patients complied fully with the study protocol. The oats cereal (Peter Kolln, Germany) used in the study was tested for evidence of gluten contamination using reverse phase high performance liquid chromatography, enzyme linked immunoassay, and polymerase chain reaction techniques and was shown to be entirely gluten free.
The patients were assessed clinically at 0, 1, 4, and 12 weeks. Laboratory investigations were performed at each of these visits and included full haematological and biochemical profiles and serological tests for antibodies to gliadin and endomysium. Duodenal biopsies were obtained endoscopically before the start of oats challenge and after 12 weeks. The biopsy specimens underwent standard evaluation for evidence of morphological damage. Furthermore, two independent observers performed intraepithelial lymphocyte counts, and enterocyte height (in μm) was measured by computerised image analysis.
Throughout the oats challenge all patients remained asymptomatic with normal haematological and biochemical indices. Endomysial and gliadin antibody values were unaltered by the oats supplement. No morphological damage was evident on standard histological evaluation. Quantitative histological examination showed no significant change in intraepithelial lymphocyte count or enterocyte height (table 1). Two patients were subsequently given a gluten “micro-challenge” consisting of 500 mg of gluten daily for six weeks: both developed histological evidence of relapse, and in one patient the antibody tests became positive.
This study shows the safety of adding oats to the gluten-free diet of 10 patients with coeliac disease. Seven of the patients have continued to take the same quantity of oats for more than 12 months without adverse effect. These findings are in agreement with a recently published study.2 In that study, however, the authors stated that they excluded coeliac patients with “severe” disease. No such policy was adopted in our study, and two of our patients were subsequently shown to be exquisitely sensitive when given a gluten micro-challenge. A third patient was also shown to be very sensitive to trace quantities of gluten taken inadvertently.
Activation of the immune system by cereal protein is likely to be centrally involved in the pathogenesis of coeliac disease,3 and evidence of immunological stimulation is a sensitive marker of disease activation. Such evidence includes lymphocyte infiltration of the surface epithelium4 and the production of antibodies to endomysium and gliadin. Oats challenge caused no change in these parameters whereas in the patients given a gluten microchallenge, abnormalities were observed.
Our results suggest that oats cereal is neither toxic nor immunogenic in coeliac disease. This has important implications for the coeliac population since the inclusion of oats would substantially improve the fibre and nutrient content of their gluten-free diet.5 The knowledge that oats are not toxic may help to define the toxic moiety in other cereals.
Conflict of interest None.