title: An optimized 13C-urea breath test for the diagnosis of H pylori infection.
abstract: OBJECTIVE
  To validate an optimized (13)C-urea breath test ((13)C-UBT) protocol for the diagnosis of H pylori infection that is cost-efficient and maintains excellent diagnostic accuracy.
  
  
  METHODS
  70 healthy volunteers were tested with two simplified (13)C-UBT protocols, with test meal (Protocol 2) and without test meal (Protocol 1). Breath samples were collected at 10, 20 and 30 min after ingestion of 50 mg (13)C-urea dissolved in 10 mL of water, taken as a single swallow, followed by 200 mL of water (pH 6.0) and a circular motion around the waistline to homogenize the urea solution. Performance of both protocols was analyzed at various cut-off values. Results were validated against the European protocol.
  
  
  RESULTS
  According to the reference protocol, 65.7% individuals were positive for H pylori infection and 34.3% were negative. There were no significant differences in the ability of both protocols to correctly identify positive and negative H pylori individuals. However, only Protocol 1 with no test meal achieved accuracy, sensitivity, specificity, positive and negative predictive values of 100%. The highest values achieved by Protocol 2 were 98.57%, 97.83%, 100%, 100% and 100%, respectively.
  
  
  CONCLUSIONS
  A 10 min, 50 mg (13)C-UBT with no test meal using a cut-off value of 2-2.5 is a highly accurate test for the diagnosis of H pylori infection at a reduced cost.
authors: School of Medicine, University of Antioquia, Medellín, Colombia. gcampuzano@hematologico.com
authors: Germán
authors: G
authors: Campuzano-Maya
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014508:Urea / Q000008:administration & dosage
chemical_list: D002247:Carbon Isotopes; D014508:Urea