C-13-UREA BREATH TEST IN HELICOBACTER-PYLORI DIAGNOSIS AND ERADICATION - CORRELATION TO HISTOLOGY, ORIGIN OF FALSE RESULTS, AND INFLUENCE OF FOOD-INTAKE

Background: Which protocol is optimal for the C-13-urea breath test (U BT) for Helicobacter pylori detection is controversial. This study aim ed to characterize a very simple UBT protocol for the clinical routine (two-point-analysis performed with 75 mg C-13-urea and citric acid) w ith special consideration of 'false' UBT results. Results: UBT was eva luated in reference to histology (Warthin-Starry). In mismatching resu lts re-gastroscopy was performed. By UBT, 74 of 77 patients with H. py lori-positive histology were detected (sensitivity, 96%). The false-ne gative UBTs were due to low colonization densities during spontaneous N. pylori elimination or pyloric obstruction. Seven of 49 patients wit h negative histology had a positive UBT, but re-gastroscopy showed tha t all of them had a positive histology when multiple antral biopsy spe cimens were taken (UBT specificity, 100%). UBT correlated only weakly with H. pylori colonization density. No correlation was found between UBT and gastric neutrophil and lymphocyte infiltration. UBT reproducib ility was excellent (93 of 94 in a 6-month period). Non-fasting condit ions induced a shift to lower UBT results in H. pylori-positive and to higher UBT results in negative patients, resulting in 2 of 10 false-p ositive and 1 of 10 false-negative UBTs. Conclusion: This simple versi on of the urea breath test combines the highest sensitivity and specif icity with excellent reproducibility. It is superior to histologic det ection of H. pylori in the clinical routine and an optimal tool for mo nitoring H. pylori eradication. Fasting conditions are required for th e test.