title: The effect of GI bleeding on Helicobacter pylori diagnostic testing: a prospective study at the time of bleeding and 1 month later.
abstract: BACKGROUND
  Some case series and cohort studies suggest that acute GI bleeding decreases the sensitivity of Helicobacter pylori diagnostic testing.
  
  
  OBJECTIVE
  To assess H pylori biopsy testing in patients with acute upper-GI bleeding and 1 month later.
  
  
  METHODS
  Prospective cohort study using patients as their own controls.
  
  
  METHODS
  Urban county hospital.
  
  
  METHODS
  Sixty-one patients with acute variceal bleeding.
  
  
  METHODS
  Antral and body endoscopic biopsies at admission and 1 month later.
  
  
  METHODS
  CLOtest and histologic examinations were performed and biopsy specimens were coded and mixed for blinded histologic examination for H pylori density and inflammation.
  
  
  RESULTS
  CLOtest results changed from H pylori negative at baseline to H pylori positive at 1 month in two patients (3%), from H pylori positive to H pylori negative in 6 patients (10%), and remained the same in 53 (87%). Histologic results changed from H pylori negative at baseline to H pylori positive at 1 month in two patients (3%), from H pylori positive to H pylori negative in 5 patients (8%), and remained the same in 54 (89%). Changes occurred only in patients with low H pylori density. No significant increase in H pylori density or change in inflammatory cell infiltration was seen. CLOtest sensitivity was 8% higher with bleeding vs. 1 month after bleeding (79% vs. 71%; 95% CI of difference was -11% to 27%; i.e., maximal potential decrease in sensitivity with bleeding is 11%).
  
  
  CONCLUSIONS
  The population is not one for which H pylori testing is recommended, and biopsy test performance was less consistent than expected.
  
  
  CONCLUSIONS
  Acute-GI bleeding did not decrease the sensitivity of rapid urease testing, unless the effect lasts more than 1 month. Furthermore, bleeding did not produce falsely negative histologic examinations for H pylori, decrease H pylori density, or alter inflammatory cell infiltration. However, given the lower than expected overall CLOtest sensitivity and frequent use of proton pump inhibitors for GI bleeding, histology may be preferred in this setting.
authors.affiliation: GI Division, Department of Medicine, University of Southern California, Los Angeles, California 90033, USA.
authors.forename: Loren A
authors.initials: LA
authors.lastname: Laine
authors.forename: Rahul A
authors.initials: RA
authors.lastname: Nathwani
authors.forename: Wesley
authors.initials: W
authors.lastname: Naritoku
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D004932:Esophageal and Gastric Varices / Q000150:complications; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000150:complications*; D016481:Helicobacter Infections / Q000150:complications / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000201:enzymology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013270:Stomach / Q000382:microbiology / Q000473:pathology; D014510:Urease / Q000032:analysis
chemical_list: D014510:Urease