Pediatric Xylose Absorption Test: Measurements in Blood Preferable to Measurements in Urine

Abstract

Abstract Data from 129 pediatric patients given oral xylose tolerance tests were reviewed and statistically analyzed to determine if blood concentrations are a more acceptable diagnostic tool than urinary excretion. After oral administration of D-(+)-xylose, blood xylose concentrations were measured at 0.5, 1, 2, 3, and 4 h, and a 5-h urine sample was analyzed. Urinary xylose excretion was more variable than blood concentration. The best criterion of celiac disease through blood sampling is a failure of blood xylose to increase during the first hour of the test. An age difference was observed but appears to be critical only if the patient is less than six months old: the lower limits of normal as determined at 0.5, 1, and 2 h are 10, 15, and 15 mg/100 ml, respectively, for patients less than six months old; and 15, 20, and 20 mg/100 ml, respectively, for older patients.