title: Factors that affect results of the 13C urea breath test in Japanese patients.
abstract: BACKGROUND
  The 13C urea breath test (UBT) is considered to be the most accurate way of diagnosing Helicobacter pylori infection. Our objective was to investigate the accuracy of the UBT in Japanese patients and the association of UBT values with histological findings.
  
  
  METHODS
  A total of 169 consecutive patients were studied by endoscopy with histology, by serology with IgG antibody and test serum pepsinogen (PG), and by UBT. The association between UBT values and histological findings and the PG I / II ratio were analyzed in H. pylori-positive patients.
  
  
  RESULTS
  Of 169 Japanese patients, 135 were H. pylori-positive on both histology and serology analysis, 27 were H. pylori-negative on both histology and serology analysis, and 7 patients showed differing results. Using a cutoff value of 2.5 per thousand, test sensitivity was 100%, while specificity was 96%. Among the 135 H. pylori-positive patients, a significant relation was observed between UBT value and H. pylori colonization density of the corpus and antrum, neutrophil activity of the antrum, atrophy, and intestinal metaplasia of the corpus in the H. pylori-positive patients. Also, UBT values correlated with the PG I /II ratio. In multivariate analysis, the PG I /II ratio was the most important factor related to UBT values (odds ration [OR], 4. 99; 95% confidence interval, 1.60-15.55).
  
  
  CONCLUSIONS
  The UBT is an accurate method for detecting H. pylori infection in the Japanese population, which shows a high prevalence of atrophic gastritis. Values are affected by H. pylori infection and by the severity of atrophic gastritis.
authors.affiliation: Gastrointestinal Unit, First Department of Internal Medicine, University School of Medicine, Hiroshima, Japan.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: K
authors.initials: K
authors.lastname: Haruma
authors.forename: T
authors.initials: T
authors.lastname: Kamada
authors.forename: M
authors.initials: M
authors.lastname: Mihara
authors.forename: K
authors.initials: K
authors.lastname: Komoto
authors.forename: M
authors.initials: M
authors.lastname: Yoshihara
authors.forename: K
authors.initials: K
authors.lastname: Sumii
authors.forename: G
authors.initials: G
authors.lastname: Kajiyama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D020116:Pepsinogen A / Q000378:metabolism; D020115:Pepsinogen C / Q000378:metabolism; D011786:Quality Control; D012680:Sensitivity and Specificity; D014508:Urea
chemical_list: D002247:Carbon Isotopes; D020115:Pepsinogen C; D014508:Urea; D020116:Pepsinogen A