[Usefulness of the serum-xylose-test in comparison with small-intestine morphology in the malabsorption syndrome].

In 148 children, 4 months to 14 1/2 years old, 192 serum-xylose-tests (XT) and small bowel biopsies have been performed because of suspected intestinal malabsorption. The results of the XT and of the biopsies were compared to investigate the diagnostic value of the XT with respect to the morphology of the small bowel mucosa. Further we wanted to determine at which time after the oral intake of xylose the best correlation of XT and morphology can be expected. In children with normal mucosa the XT differed significantly from those with subtotal mucosal atrophy but not with partial villous atrophy. However, partial villous atrophy could be differentiated from subtotal villous atrophy with the same test. In children with subtotal villous atrophy a statistically significant age-dependency could be observed, comparing children being less or more than 2 years old and also a dependency from periods with gluten-free diet. Partial villous atrophy with or without coeliac disease cannot be differentiated by means of the XT. Best correlation of the XT and the morphology of the small bowel mucosa can be found 60 minutes after the oral xylose load; no additional information is obtained by more blood-xylose-determinations (e.g. 30, 90, 120, 180 minutes). Because of the rather high standard deviation of the individual blood xylose values no exact prediction can be made from the XT to the mucosal morphology. Therefore the XT is only of value for screening purposes and its results should not influence the indication for a small bowel biopsy, derived from clinical considerations.