CARBON-13 - LABELED UREA BREATH TEST FOR THE DIAGNOSIS OF HELICOBACTER-PYLORI INFECTION IN CHILDREN

Helicobacter pylori infection is mainly acquired in childhood, and stu dies on the epidemiology of this infection depend on the availability of a noninvasive diagnostic test for use in children. The aim of this study was to determine whether the carbon 13-labeled urea breath test (UBT) can be used in children by evaluating: (1) its sensitivity and s pecificity compared with either culture or both rapid urease test and histologic examination, (2) whether a test meal or a prolonged fast is required, (3) the usefulness after treatment for H. pylori. Eighty-ei ght children (mean age, 10.6 +/- 4.19 years) who were undergoing upper endoscopy were studied while fasting, not fasting, and after treatmen t. Children were given 50 mg of C-13-urea if they weighed less than 50 kg or 75 mg of C-13-urea if they weighed more than 50 kg with 50 mg o f a glucose polymer solution in 7.5 mi of water. Breath samples were c ollected at baseline and at 15, 30, 45, and 60 minutes. In 63 fasting children the UBT was 100% sensitive and 97.6% specific at 30 minutes w ith a cutoff value of 3.5 delta (CO2)-C-13 per mil. Nonfasting tests i n 23 children, performed between 1 and 2 hours after their usual meal, were 100% sensitive and 91.6% specific. In 13 children fed directly b efore the UBT, the sensitivity of the test was reduced to 50%. Thirty minutes was the optimal sampling time. There was a significant decreas e in specificity when samples were obtained at 15 minutes, possibly ca used by the interference of oral urease-producing organisms. The test was 100% sensitive and specific in 20 children after treatment for H, pylori infection. The UBT is a highly sensitive and specific test for the diagnosis of H, pylori infection in children. Neither a prolonged fast nor a test meal is required.