Comparative Reliability of d‐Xylose Absorption and Serum β‐Carotene Measurements in Small Intestinal Disease

Comparative reliability of d‐xylose absorption and serum β‐carotene measurements was studied in 63 healthy and sick children suspected of having proximal small intestinal disease. Group 1 included children with newly diagnosed celiac disease (CD) who were on a normal diet (xylose, n = 46; carotene, n = 43); group 2 included children with CD in remission (xylose, n = 17; carotene, n = 15); group 3 included children with CD in remission, but who were exposed to a gluten‐containing diet for an average of 1.4 years (xylose, n = 19; carotene, n = 17); and group 4 included 17 healthy children, insofar as this study is concerned, in whom serum carotene was examined. The means of serum xylose of groups 1 and 3 were significantly lower than the mean of group 2 (p < 0.001 in both cases). d‐Xylose had a sensitivity of 76.9% and a specificity of 100%. The mean serum carotene concentration for group 2 patients with CD in remission was equal to the mean of group 4, which included healthy children. The means of groups 1 and 3 were significantly lower than the means of groups 2 and 4 (p < 0.001 in all cases). Serum β‐carotene had a sensitivity of 95% and a specificity of 87.5%. The use of these two serum tests in combination would give a specificity of 100% and a sensitivity of 94.1%. Although 1‐h serum xylose was as efficient as serum β‐carotene in newly diagnosed children with CD, carotene was superior to xylose in patients with CD who were challenged with gluten (group 3), and therefore the measurement of carotene, which has the higher sensitivity, may be useful in the detection of children with CD who lack strict adherence to the gluten‐free diet.