title: The best gastric site for obtaining a positive rapid ureas test.
abstract: BACKGROUND
  Rapid ureas tests (RUTs) provide a simple, sensitive method of detecting Helicobacter pylori infection.
  
  
  OBJECTIVE
  Our aim, therefore, was to determine whether the yield of detecting H. pylori infection by RUT varied depending on the site of gastric biopsy.
  
  
  METHODS
  Gastric biopsies were obtained from 50 patients for RUT by use of hpfast (GI Supply, Camp Hill, PA). Biopsies were taken from the prepyloric greater curve antrum, from the gastric angle, and from the greater curve in mid-corpus. One biopsy specimen was placed in the RUT gel, and the biopsy from the adjacent mucosa was placed in formalin for subsequent histological evaluation by using the Genta stain. RUTs were examined and scored at intervals of 5, 10, 15, 30, and 45 minutes and after 1, 2, 4, and 24 hours.
  
  
  RESULTS
  Fifty patients were entered in the rest (150 RUTs), 32 having H. pylori infection. There were no false-positive RUTs (specificity, 100%). The gastric angle site was positive in 100%. The prepyloric site was positive in 87%, and the corpus site was positive in 84.4% (p < .052 for angle or prepyloric antrum versus corpus). The most common pattern was for all to be positive (74%). The median time to positivity was similar with angle and prepyloric sites (37.5 and 60 minutes, respectively, p = not significant) and shorter than the corpus biopsy (180 minutes); (p < .05 for angle or prepyloric antrum versus corpus).
  
  
  CONCLUSIONS
  The maximum probability for detecting H. pylori infection using a RUT is to obtain a biopsy from the gastric angle. To prevent missing a positive result when intestinal metaplasia is present, we recommend that (at a minimum) biopsies be taken from both the angle and the corpus.
authors.affiliation: Department of Medicine, Veterans Affairs Medical Center, Houston, TX 77030, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Woo
authors.forename: H M
authors.initials: HM
authors.lastname: el-Zimaity
authors.forename: R M
authors.initials: RM
authors.lastname: Genta
authors.forename: M M
authors.initials: MM
authors.lastname: Yousfi
authors.forename: D Y
authors.initials: DY
authors.lastname: Graham
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D001706:Biopsy / Q000379:methods*; D004796:Clinical Enzyme Tests / Q000379:methods*; D005069:Evaluation Studies as Topic; D005753:Gastric Mucosa / Q000201:enzymology* / Q000382:microbiology; D005756:Gastritis / Q000201:enzymology*; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000201:enzymology*; D016480:Helicobacter pylori / Q000201:enzymology*; D006801:Humans; D009928:Organ Specificity; D011706:Pyloric Antrum / Q000201:enzymology / Q000382:microbiology; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D013270:Stomach / Q000201:enzymology* / Q000382:microbiology; D014510:Urease / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D011933:Reagent Kits, Diagnostic; D014510:Urease