Limitations of xylose tolerance test as a screening procedure in childhood coeliac disease

Abstract

The usefulness of the xylose tolerance test as a screening procedure for coeliac disease has been reassessed in 54 children with suspected coeliac disease. 5 and 24 hr urinary excretion rates of xylose were of no value in discriminating between patients with and without coeliac disease; similarly, the 3 hr blood xylose concentration was nondiscriminatory. Three (15.8%) patients with subtotal villous atrophy and 8 (61.5%) with partial villous atrophy due to coeliac disease had 1 hr blood xylose values which fell within the normal range. The effect of withdrawal or reintroduction of dietary gluten on sequential 1 hr blood xylose levels was variable and generally unhelpful in predicting those patients who developed gluten induced mucosal changes. The results of this study emphasize the serious limitations of the xylose tolerance test as a screening procedure in childhood coeliac disease. It is recommended that the use of the urinary xylose test should be abandoned in the pediatric population. A normal 1 hr blood xylose value does not exclude a diagnosis of coeliac disease even in young children who have never received a gluten free diet. A clinical suspicion of coeliac disease remains the most important single factor in deciding whether to perform a jejunal biopsy.