title: Qualitative and quantitative clinical evaluation of the laser-assisted ratio analyser for detection of Helicobacter pylori infection by (13)C-urea breath tests.
abstract: OBJECTIVE
  Currently, the (13)C-urea breath test is the reference method for non-invasive diagnosis of Helicobacter pylori infection and therapy control. Therefore, new technologies have been developed to measure the ratio of (13)CO(2)/(12)CO(2) in breath. The laser-assisted ratio analyser (LARA) device is based on optogalvanic effects of the stimulated CO(2) molecules.
  
  
  METHODS
  In this study, the LARA system is prospectively compared to conventional isotope ratio mass spectrometry (IRMS) analysis of (13)C-urea breath tests.
  
  
  METHODS
  The (13)C-urea breath test was used to screen 103 patients for H. pylori infection. Breath samples were analysed by LARA and IRMS techniques.
  
  
  RESULTS
  Seven breath tests could not be analysed by the LARA system, one by IRMS. Out of the remaining 95 breath tests, 13 were positive for H. pylori infection (13.7%). In reference to IRMS analysis (with a cut-off of > 5 delta per thousand at 30 min), LARA produced one false positive and one false negative breath test result giving a sensitivity of 92.3% and a specificity of 98.8%. The mean difference in delta over baseline values between IRMS and LARA measurements was 2.02 delta per thousand +/- 5.48 delta per thousand.
  
  
  CONCLUSIONS
  LARA allows the reliable qualitative evaluation of 13C-urea breath tests, but the quantitative results differ from IRMS findings.
authors.affiliation: Department of Internal Medicine II, University Hospital, Frankfurt, Germany. Braden@em.uni-frankfurt.de
authors.forename: B
authors.initials: B
authors.lastname: Braden
authors.forename: C
authors.initials: C
authors.lastname: Gelbmann
authors.forename: C F
authors.initials: CF
authors.lastname: Dietrich
authors.forename: W F
authors.initials: WF
authors.lastname: Caspary
authors.forename: J
authors.initials: J
authors.lastname: Schölmerich
authors.forename: G
authors.initials: G
authors.lastname: Lock
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests / Q000379:methods; D002247:Carbon Isotopes; D002648:Child; D005260:Female; D005767:Gastrointestinal Diseases / Q000382:microbiology; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000295:instrumentation*; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014508:Urea
chemical_list: D002247:Carbon Isotopes; D014508:Urea