title: Microdose 14C-urea breath test offers diagnosis of Helicobacter pylori in 10 minutes.
abstract: OBJECTIVE
  The urea breath test diagnoses Helicobacter pylori infection of the stomach by identifying the urease enzyme activity of the bacterium. In this "microdose" version of the test, 1 microCi 14C-urea is given orally in a capsule. Our objectives were: 1) to evaluate a microdose 14C-urea breath test capsule in a gastroenterology outpatient setting, 2) to determine the diagnostic ranges of the 14C-urea breath test for HP-positive and HP-negative patients, 3) to define the sensitivity and specificity of the test, and 4) to see whether breath sample results changed when they were mailed to a remote site for analysis.
  
  
  METHODS
  In a prospective blinded study, we breath-tested 200 fasted patients before elective outpatient endoscopy. At endoscopy, two gastric biopsy samples were taken and were examined for curved organisms; a third biopsy specimen was evaluated with a rapid urease test (CLOtest). Breath samples were mailed in aluminized balloons to a testing laboratory.
  
  
  RESULTS
  Using a single breath sample collected at 10 min, with > or = 200 dpm as positive, the breath test correctly classified 63 of 65 HP-positive patients (sensitivity 97%, CI 89-99%), and 128 of 135 HP-negative patients (specificity 95%, CI 90-98%). Radiation exposure from the test equated to natural background received in 1 day. No adverse events were caused by the breath test.
  
  
  CONCLUSIONS
  The 14C-urea capsule breath test (PYtest) is a convenient noninvasive test for the detection of gastric H. pylori infection. Accuracy is equivalent to invasive methods such as histology. Results can be obtained within 15 min if a counting instrument is nearby, or breath samples can be mailed to a testing laboratory for analysis.
authors.affiliation: University of Virginia Health Sciences Center, Martha Jefferson Hospital, Charlottesville, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Peura
authors.forename: D J
authors.initials: DJ
authors.lastname: Pambianco
authors.forename: K R
authors.initials: KR
authors.lastname: Dye
authors.forename: C
authors.initials: C
authors.lastname: Lind
authors.forename: H F
authors.initials: HF
authors.lastname: Frierson
authors.forename: S R
authors.initials: SR
authors.lastname: Hoffman
authors.forename: M J
authors.initials: MJ
authors.lastname: Combs
authors.forename: E
authors.initials: E
authors.lastname: Guilfoyle
authors.forename: B J
authors.initials: BJ
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D001944:Breath Tests / Q000379:methods*; D004724:Endoscopy; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000201:enzymology / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D014508:Urea; D014510:Urease / Q000032:analysis
chemical_list: D014508:Urea; D014510:Urease