title: Clinical studies of 13C-urea breath test in Japan.
abstract: The urea breath test (UBT) using isotope carbon is a non-invasive method for diagnosing H. pylori infection. In Japan, only 13C-UBT using a stable isotope is available, since the clinical use of radioactive isotope 14C-compounds is prohibited. Since there is no worldwide standard protocol for the 13C-UBT, it is therefore important to standardize this test to obtain a cheap, easy, reproducible method. Factors affecting the outcome of 13C-UBT values include sampling times and frequency, the amount of 13C-urea, the cut-off value, the avoidance of oral urease activity, and changes in gastric emptying times and 13C-urea distribution. Mouth rinsing reduces false-positive results due to oral urease activity, particularly within 20 min after ingestion of 13C-urea. A Japanese multicenter trial has shown that the diagnostic utility of 13C-UBT is superb, with the cut-off value 2.5/1000 in 20-min samples after ingestion of 100 mg 13C-urea. The 13C-UBT is a very useful method for diagnosing H. pylori infection.
authors.affiliation: Third Department of Internal Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kato
authors.forename: M
authors.initials: M
authors.lastname: Asaka
authors.forename: S
authors.initials: S
authors.lastname: Ohara
authors.forename: T
authors.initials: T
authors.lastname: Toyota
mesh_terms: D001944:Breath Tests; D002247:Carbon Isotopes; D002986:Clinical Trials as Topic; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D007564:Japan; D015203:Reproducibility of Results; D014508:Urea / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D014508:Urea