title: Nondispersive isotope-selective infrared spectroscopy: a new analytical method for 13C-urea breath tests.
abstract: BACKGROUND
  Currently, stable isotope techniques in breath tests using 13C-labeled substrates are limited to a few centers equipped with expensive and complex isotope ratio mass spectrometry (IRMS). Although breath samples can be mailed to these centers, widespread application of 13C breath tests would be more feasible with a cheaper and more practicable analysis system at hand.
  
  
  METHODS
  We therefore tested the newly developed nondispersive isotope-selective infrared spectrometer (NDIRS) with reference to IRMS in a clinical setting comparing the results of both techniques in 538 consecutive 13C-urea breath tests performed for the detection of Helicobacter pylori infection.
  
  
  RESULTS
  With NDIRS five false-positive and three false-negative results were observed; that is, the sensitivity of NDIRS was 98.3%, and the specificity was 98.6%. The delta over base-line values of both devices correlated linearly (Y = 0.87 +/- 0.01 X + 0.29 +/- 1.5; r = 0.95; p < 0.0001; n = 538).
  
  
  CONCLUSIONS
  When running this large number of breath tests in 3 days, the NDIRS proved to be a reliable, stable, and easy-to-operate analytical tool, which is well qualified for gastroenterologic application in the diagnostic routine. Both the price and the easy handling of NDIRS will facilitate the widespread use of the noninvasive stable isotope technique for 13C breath tests.
authors: Medical Dept. II, Johann Wolfgang Goethe University, Frankfurt/Main, Germany.
authors: B
authors: B
authors: Braden
authors: F
authors: F
authors: Schäfer
authors: W F
authors: WF
authors: Caspary
authors: B
authors: B
authors: Lembcke
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods*; D014508:Urea
chemical_list: D002247:Carbon Isotopes; D014508:Urea