title: Influence of Helicobacter pylori infection on the phenotype of Crohn's disease.
abstract: OBJECTIVE
  Very little is known about the impact of Helicobacter pylori (H. pylori) infection on Crohn's disease. In this study we investigated a possible influence of H. pylori on the phenotype of Crohn's disease.
  
  
  METHODS
  Patients with Crohn's disease who had gastric biopsy between 1990 and 1994 and a clinical follow-up in our outpatient clinic for at least 2 yr were included in the study. The mean number of flare-ups per year of follow-up, the mean numbers of intestinal resections per year of disease duration, and primary disease location were compared in H. pylori-positive and -negative patients. Various regression models were calculated to test the influence of H. pylori status on these parameters, correcting for smoking habits and disease duration.
  
  
  RESULTS
  Of 131 patients, 50 (38.2%) were H. pylori positive and 62 (47.3%) were smokers. Due to a significant interaction between smoking habits and H. pylori infection, regression models were calculated separately for smokers and nonsmokers. Nonsmokers without H. pylori infection had more flare-ups than nonsmokers with H. pylori infection (0.77 [0.57-0.97] vs 0.29 [0.16-0.42]; p < 0.01; mean [95% confidence interval]). In contrast, nonsmokers without H. pylori infection had less intestinal resections than nonsmokers infected with H. pylori (0.08 [0.04-0.12] vs 0.11 [0.07-0.15]; p < 0.05). These differences were not significant for smokers (p < 0.41 and p < 0.07). There was a predominance of small bowel disease in H. pylori-positive patients, which did not reach statistical significance.
  
  
  CONCLUSIONS
  Our data indicate that H. pylori influences the phenotype of Crohn's disease, especially in nonsmokers.
authors.affiliation: Clinic of Internal Medicine IV, Department of Gastroenterology and Hepatology, AKH, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Püspök
authors.forename: C
authors.initials: C
authors.lastname: Dejaco
authors.forename: G
authors.initials: G
authors.lastname: Oberhuber
authors.forename: T
authors.initials: T
authors.lastname: Waldhör
authors.forename: A M
authors.initials: AM
authors.lastname: Hirschl
authors.forename: H
authors.initials: H
authors.lastname: Vogelsang
authors.forename: C
authors.initials: C
authors.lastname: Gasche
mesh_terms: D000328:Adult; D001706:Biopsy; D003108:Colonic Diseases / Q000235:genetics / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology; D016001:Confidence Intervals; D003424:Crohn Disease / Q000235:genetics* / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori; D006801:Humans; D007421:Intestine, Small / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D010641:Phenotype; D016012:Poisson Distribution; D012907:Smoking / Q000009:adverse effects; D013270:Stomach / Q000382:microbiology / Q000473:pathology