title: Lower-dose (13)C-urea breath test to detect Helicobacter pylori infection-comparison between infrared spectrometer and mass spectrometry analysis.
abstract: BACKGROUND
  The expense of the (13)C-urea breath test (UBT) to detect Helicobacter pylori infection is mainly due to the cost of (13)C-urea and the analysis using isotope ratio mass spectrometry (IRMS).
  
  
  OBJECTIVE
  To test whether a UBT, using a lower dose of urea and lower-priced isotope-selective nondispersive infrared spectrometry (INIS), can preserve diagnostic efficacy in clinical practice.
  
  
  METHODS
  A total of 177 dyspeptic patients received endoscopy for H. pylori culture and histology. All of them received a UBT in which the duplicate baseline, 10 min, and 15 min breath samples after ingestion of 50 mg (13)C-urea were collected to analyse the excess (13)CO(2)/(12)CO(2) ratio (ECR) by IRMS (ABCA, Europa Scientific, UK) and INIS (UBiT-IR200, Photal Otsuka Electronics, Japan), respectively.
  
  
  RESULTS
  Of the 177 patients, 84 were infected and 93 were uninfected with H. pylori. A close correlation of ECR was found between IRMS and INIS (r=0.9829 at 10 min; r=0.9918 at 15 min, P < 0.0001). Analysing the 15-min samples, UBT by both IRMS and INIS achieved the same sensitivity (96. 4%) and specificity (98.9%).
  
  
  CONCLUSIONS
  INIS is as effective as IRMS for UBT, and can use a lower dose of (13)C-urea. This can provide an economic UBT, using the lower-priced INIS and a low dose of (13)C-urea.
authors.affiliation: Department of Internal Medicine, National Cheng Kung University, Tainan, Taiwan. sheubs@mail.ncku.edu.tw
authors.forename: B S
authors.initials: BS
authors.lastname: Sheu
authors.forename: S C
authors.initials: SC
authors.lastname: Lee
authors.forename: H B
authors.initials: HB
authors.lastname: Yang
authors.forename: H W
authors.initials: HW
authors.lastname: Wu
authors.forename: C S
authors.initials: CS
authors.lastname: Wu
authors.forename: X Z
authors.initials: XZ
authors.lastname: Lin
authors.forename: J J
authors.initials: JJ
authors.lastname: Wu
mesh_terms: D000328:Adult; D001944:Breath Tests; D002247:Carbon Isotopes; D005260:Female; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000473:pathology; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D019265:Spectroscopy, Near-Infrared; D013270:Stomach / Q000473:pathology; D014508:Urea / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D014508:Urea