MICRODOSE C-14 UREA BREATH TEST OFFERS DIAGNOSIS OF HELICOBACTER-PYLORI IN 10 MINUTES

Objectives: The urea breath test diagnoses Helicobacter pylori infecti on of the stomach by identifying the urease enzyme activity of the bac terium, In this ''microdose'' version of the test, 1 mu Ci C-14-urea i s given orally in a capsule, Our objectives were: 1) to evaluate a mic rodose C-14-urea breath test capsule in a gastroenterology outpatient setting, 2) to determine the diagnostic ranges of the C-14-urea breath test for HP-positive and HP-negative patients, 3) to define the sensi tivity and specificity of the test, and 4) to see whether breath sampl e results changed when they were mailed to a remote site for analysis, Methods: In a prospective blinded study, we breath-tested 200 fasted patients before elective outpatient endoscopy, At endoscopy, two gastr ic biopsy samples were taken and were examined for curved organisms; a third biopsy specimen was evaluated with a rapid urease test (CLOtest ). Breath samples were mailed in aluminized balloons to a testing labo ratory, Results: Using a single breath sample collected at 10 min, wit h equal to or greater than 200 dpm as positive, the breath test correc tly classified 63 of 65 HP-positive patients (sensitivity 97%, CI 89-9 9%), and 128 of 135 DR-negative patients (specificity 95%, CI 90-98%). Radiation exposure from the test equated to natural background receiv ed in 1 day, No adverse events were caused by the breath test. Conclus ions: The C-14-urea capsule breath test (PYtest) is a convenient nonin vasive test for the detection of gastric H. pylori infection. Accuracy is equivalent to invasive methods such as histology, Results can be o btained within 15 min if a counting instrument is nearby, or breath sa mples can be mailed to a testing laboratory for analysis.