title: Evaluation of Helicobacter pylori stool antigen test before and after eradication therapy.
abstract: OBJECTIVE
  The Helicobacter pylori stool antigen (HpSA) test is useful for initial diagnosis of H. pylori infection, but there is disagreement regarding its diagnostic accuracy after eradication therapy. The aim of the present study was to evaluate the diagnostic accuracy of the HpSA test before and after eradication therapy.
  
  
  METHODS
  One hundred and thirty-six patients underwent upper gastrointestinal endoscopy with biopsies for the diagnosis of H. pylori infection using culture, histology and the rapid urease test. Fifty-four H. pylori-positive patients were treated with 1-week triple therapy. Six to 10 weeks after the end of therapy, the patients underwent re-endoscopy and received the same biopsy-based methods. In addition, the 13C-urea breath test was performed. The HpSA test was performed before and 6-10 weeks after the end of therapy. In 23 patients, the HpSA test was also performed at the end of therapy.
  
  
  RESULTS
  Before therapy, the sensitivity and specificity of the HpSA test was 98.3% (95% confidence interval (CI): 95.9-100%) and 95.0% (95% CI: 75.1-99.9%), respectively. At the end of therapy, the HpSA tests were all negative both for eradication and non-eradication patients. The sensitivity and specificity of the HpSA test after eradication therapy were 90% (95% CI: 55.5-99.7%) and 97.7% (95% CI: 93.3-100%), respectively.
  
  
  CONCLUSIONS
  The HpSA test is a useful method for the diagnosis of H. pylori infection before and after eradication therapy.
authors.affiliation: The Third Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan. aki@kyorin-u.ac.jp
authors.forename: Akifumi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Kengo
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hoshiya
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Imase
authors.forename: Hajime
authors.initials: H
authors.lastname: Sugano
authors.forename: Masao
authors.initials: M
authors.lastname: Shingaki
authors.forename: Akemi
authors.initials: A
authors.lastname: Kai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Itoh
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ishida
authors.forename: Shin'ichi
authors.initials: S
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000942:Antigens, Bacterial; D001706:Biopsy; D001944:Breath Tests; D002250:Carbon Radioisotopes; D016099:Endoscopy, Gastrointestinal; D005189:False Positive Reactions; D005243:Feces / Q000737:chemistry*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors; D017494:Proton Pumps / Q000627:therapeutic use*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014508:Urea; D014510:Urease
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D002250:Carbon Radioisotopes; D054328:Proton Pump Inhibitors; D017494:Proton Pumps; D019275:Radiopharmaceuticals; D014508:Urea; D014510:Urease