title: Influence of Helicobacter pylori genotype on triple eradication therapy.
abstract: BACKGROUND
  The efficiency of Helicobacter pylori eradication varies geographically, as do many parameters that might affect therapeutic efficiency. The aims of this study were to investigate the relationship between different genotypes of H. pylori and bacterium-related histopathological lesions in patients with duodenal ulcer and to determine the effect of genotype on triple eradication therapy.
  
  
  METHODS
  Helicobacter pylori infections were analyzed in 78 duodenal ulcer patients. The cytotoxin-associated gene (cagA) and vacuolating cytotoxin gene (vacA) subtype status of cultured strains were studied by PCR. Histopathological findings were graded using a described grading system. The patients were treated with triple-therapy regimens consisting of a proton pump inhibitor and two antibiotics twice daily for 7 days. Endoscopy was repeated at 4 weeks post-therapy to monitor ulcer healing and H. pylori eradication.
  
  
  RESULTS
  The bacteria were genotyped from 66 patients, 57 of whom had H. pylori eradicated. The absence of cagA was associated with unsuccessful treatment. No difference was found with regard to vacA subtype between the successful and unsuccessful eradication groups. On histopathological examination, high H. pylori colonization density and intestinal metaplasia were associated with low eradication rate, while a high grade of neutrophil infiltration was associated with a significantly higher eradication rate.
  
  
  CONCLUSIONS
  The data confirm the importance of cagA positivity as a predictor of successful eradication. When high H. pylori colonization density and intestinal metaplasia are present, therapy appears to be less effective. Therefore, these histopathological features may be involved in an unsuccessful therapeutic outcome.
authors.affiliation: China-Japan Union Hospital of Ji Lin University, Changchun, China. zhaojj1@hotmail.com
authors.forename: Jian Jun
authors.initials: JJ
authors.lastname: Zhao
authors.forename: Jiang Bin
authors.initials: JB
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
mesh_terms: D004359:Drug Therapy, Combination; D005838:Genotype; D016481:Helicobacter Infections / Q000473:pathology / Q000517:prevention & control* / Q000628:therapy*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans