title: Posttreatment 13C-urea breath test is predictive of antimicrobial resistance to H. pylori after failed therapy.
abstract: OBJECTIVE
  We tested whether a 13C-urea breath test can predict antimicrobial resistance of Helicobacter pylori (H. pylori).
  
  
  METHODS
  Seventy patients who had failed triple eradication therapy and 108 untreated H. pylori-infected patients were given a 13C-urea breath test, endoscopy for culture of H. pylori, and assessment of clarithromycin resistance. The patients who had failed triple therapy then received 1 week of quadruple therapy to eradicate residual H. pylori.
  
  
  RESULTS
  The posttreatment value of the 13C-urea breath test expressed as excessive delta13CO2 per ml (ECR) was higher in patients with residual H. pylori with clarithromycin resistance than in those without (23.8 vs 10.6; P<.0001). With a cutoff of ECR >or< or =15, the 13C-urea breath test was 88.6% sensitive and 88.9% specific in predicting clarithromycin resistance of residual H. pylori. The H. pylori eradication rate of the rescue regimen was higher for patients with a posttreatment ECR of the 13C-urea breath test < or =15 than for those with a value >15 (93.8% vs 73.3%; P<.05). In contrast, in treatment-naive H. pylori-infected patients, the pretreatment value of the 13C-urea breath test did not differ between patients infected with clarithromycin-resistant or-sensitive isolates (P>.05).
  
  
  CONCLUSIONS
  The posttreatment value of the 13C-urea breath test is predictive of clarithromycin resistance in residual H. pylori after failed triple therapy and predicts efficacy of the rescue regimen. The value of the noninvasive test is promising for primary care physicians who need to select a rescue regimen without invasive H. pylori culture.
authors.affiliation: Department of Internal Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Ai-Wen
authors.initials: AW
authors.lastname: Kao
authors.forename: Hsiu-Chi
authors.initials: HC
authors.lastname: Cheng
authors.forename: Bor-Shyang
authors.initials: BS
authors.lastname: Sheu
authors.forename: Ching-Yih
authors.initials: CY
authors.lastname: Lin
authors.forename: Ming-Jen
authors.initials: MJ
authors.lastname: Sheu
authors.forename: Hsiao-Bai
authors.initials: HB
authors.lastname: Yang
authors.forename: Jiunn-Jong
authors.initials: JJ
authors.lastname: Wu
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001944:Breath Tests; D002247:Carbon Isotopes; D017291:Clarithromycin / Q000627:therapeutic use; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D016099:Endoscopy, Gastrointestinal; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents; D002247:Carbon Isotopes; D054328:Proton Pump Inhibitors; D017291:Clarithromycin