The 1-hr blood xylose test in the evaluation of malabsorption in infants and children

Abstract

One hundred ninety-seven 1-hr blood xylose absorption tests with 5 g of d-xylose were performed on 171 infants and children for the evaluation of malabsorption. The mean ± 1 SD blood xylose level in 78 controls was 37.0 ± 7.7 mg/dl, and 71 patients with post infectious diarrhea was 28.4 ± 11.0 mg/dl. A significant reduction (P < 0.001) was found in 10 patients with Celiac disease (12.0 ± 8.6 mg/dl) and 18 patients with intractable diarrhea syndromes (18.3 ± 12.5 mg/dl). Forty-four patients had a blood xylose level less than 20 mg/dl, and the majority (35/44) were in the groups with postinfection and intractable diarrhea syndromes. Multiple tests were performed on 20 patients. Sixty-two intestinal biopsies were correlated with 1-hr blood xylose levels. The rate of false positives was 0. The rate of false negative tests varied between 4 to 32.7% depending on the assessment of intestinal damage. Our results confirm that the 1-hr blood xylose absorption test is a sensitive indicator of severe intestinal damage. Intestinal biopsy should be considered in all patients with a l-hr blood xylose level less than 20 mg/dl. With borderline results (20 to 25 mg/dl), clinical decisions must be individualized.