DETECTION OF HELICOBACTER-PYLORI INFECTION IN CHILDREN WITH A STANDARDIZED AND SIMPLIFIED C-13-UREA BREATH TEST

Background: The C-13-urea breath test, a reliable noninvasive method o f detection of Helicobacter pylori in adults, needs validation in chil dren. Methods: in order to evaluate the diagnostic accuracy of C-13-ur ea breath test in children, the results of this test performed in 144 children were correlated with the histology and culture of contemporan eous gastric (antral and fundic) biopsy specimens. The test was perfor med with 2 mg/kg body weight C-13-Urea (maximum, 100 mg) ingested afte r a fat-rich test meal. Samples of expired breath taken at 0, 5, 10, 2 0, and 30 minutes were assayed with mass spectrometry.Results were con sidered positive when the curve of excretion of labeled carbon dioxide in the expired breath increased by 5 parts per thousand or more above the baseline. Results: Discrepancies in H. pylori status were observe d in 14 children. To improve and simplify the test, the results were r eanalyzed using different cutoff values for each sampling time. The be st results, with sensitivity of 95.7 parts per thousand and specificit y of 95.2%, were obtained with a cutoff of 3.5 parts per thousand at 2 0 minutes. Conclusions: The C-13-urea breath test is a reliable method for the noninvasive detection of H. pylori infection in children. The test can be simplified and its accuracy improved using only the 0- an d 20-minute breath samples and a cutoff of 3.5 parts per thousand inst ead of the classical 5 parts per thousand used in adults. The need for modi fication of the cutoff value may reflect the higher production o f endogenous CO2 in children.