Rectal gluten challenge and diagnosis of coeliac disease

Abstract

44 patients referred consecutively for jejunal biospy underwent rectal gluten challenge with 2g peptice-tryptic digest (Frazer''s fraction III: FF3). Rectal biopsy was done before the challenge and 6 h afterwards. Total intraepithelial lymphocytes (IEL) overlying a 104 .mu.m2 test area of muscularis mucosae were quantified by computerised image analysis. The subjects comprised 21 controls with disorders other than coeliac disease and 23 patients (14 treated, 9 untreated) with coeliac disease diagnosed by strict jejunal biopsy gold standard criteria. There were no difference between the groups in EL numbers before challenge. Coeliac disease patients but not controls responded to F3 with a rise in mucosal IEL (median 60.5% rise for treated, 63.0% for untreated). There were no response to challenge with .beta.-lactoglobulin in coeliac disease or control subjects. When a predefined, post-challenge IEL "predictive index" of more than 10% above baseline was used to indicate a diagnosis of coeliac disease., it gave a sensitivity of 90% and specificity of 91% (95% confidence intervals 78-93%). Rectal gluten challenge is a simple, safe, and reliable test of gluten sensitivity, both as a screening test for untreated coeliac disease and as a confirmatory test in patients with treated coeliac disease.