title: Endoscopic biopsy requirements for post-treatment diagnosis of Helicobacter pylori.
abstract: BACKGROUND
  Data on sensitivities of biopsy tests for Helicobacter pylori diagnosis after modern eradication therapy are limited. We assessed diagnostic yield of endoscopic biopsy tests before and after therapy in 2 U.S. multicenter double-blind trials of 10-day proton pump inhibitor-based triple therapy versus dual antibiotic therapy.
  
  
  METHODS
  Three hundred one patients with duodenal ulcer and H pylori infection had endoscopy at baseline and at 8 weeks. Four antral and 3 body biopsies were taken at both endoscopies: 1 antral biopsy for a rapid urease test (CLOtest), 2 antral and 2 body biopsies for histologic examination (Genta stain), and 1 antral and 1 body biopsy for culture.
  
  
  RESULTS
  The 2 same-site biopsies (antral or body) for histologic examination were in agreement in 97% of cases before treatment and 100% after triple therapy. Histologic examination of antral biopsies without body biopsies missed H pylori infection in 2% of patients before treatment and 5% after triple therapy. Posttreatment sensitivities for triple therapy were significantly lower than pretreatment sensitivities for all tests (e. g., 18% decrease in sensitivity in antral histology, 22% decrease in antral culture); decreases in sensitivity were greater after triple therapy than after the less effective dual therapy. CLOtest plus histology had a post-treatment sensitivity of 96% in the triple therapy group.
  
  
  CONCLUSIONS
  A single antral biopsy for histology provides excellent sensitivity for H pylori in untreated patients, but, after effective therapy, sensitivities of biopsy tests decrease. Use of more than one method of testing may increase diagnostic yield when assessing post-treatment H pylori status with endoscopy, whereas the addition of multiple biopsies for each type of test is of more limited value.
authors.affiliation: USC School of Medicine, Los Angeles, California, and Astra Pharmaceuticals, Wayne, PA, USA.
authors.forename: L
authors.initials: L
authors.lastname: Laine
authors.forename: J
authors.initials: J
authors.lastname: Sugg
authors.forename: L
authors.initials: L
authors.lastname: Suchower
authors.forename: G
authors.initials: G
authors.lastname: Neil
mesh_terms: D000658:Amoxicillin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D000897:Anti-Ulcer Agents / Q000008:administration & dosage*; D001706:Biopsy / Q000379:methods*; D017291:Clarithromycin / Q000008:administration & dosage*; D004311:Double-Blind Method; D016099:Endoscopy, Gastrointestinal; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy*; D016480:Helicobacter pylori; D006801:Humans; D009853:Omeprazole / Q000008:administration & dosage*; D010406:Penicillins / Q000008:administration & dosage*; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D010406:Penicillins; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole