title: Helicobacter pylori iceA, clinical outcomes, and correlation with cagA: a meta-analysis.
abstract: BACKGROUND
  Although the iceA (induced by contact with epithelium) allelic types of Helicobacter pylori have been reported to be associated with peptic ulcer, the importance of iceA on clinical outcomes based on subsequent studies is controversial. The aim of this study was to estimate the magnitude of the risk for clinical outcomes associated with iceA.
  
  
  METHODS
  A literature search was performed using the PubMed and EMBASE databases for articles published through April 2011. Published case-control studies examining the relationship between iceA and clinical outcomes (gastritis, peptic ulcer, including gastric ulcer and duodenal ulcer, and gastric cancer) were included.
  
  
  RESULTS
  Fifty studies with a total of 5,357 patients were identified in the search. Infection with iceA1-positive H. pylori increased the overall risk for peptic ulcer by 1.26-fold (95% confidence interval [CI], 1.09-1.45). However, the test for heterogeneity was significant among these studies. Sensitivity analysis showed that the presence of iceA1 was significantly associated with peptic ulcer (odds ratio [OR] = 1.25, 95% CI = 1.08-1.44). The presence of iceA2 was inversely associated with peptic ulcer (OR = 0.76, 95% CI = 0.65-0.89). The presence of iceA was not associated with gastric cancer. Most studies examined the cagA status; however, only 15 studies examined the correlation and only 2 showed a positive correlation between the presence of cagA and iceA1.
  
  
  CONCLUSIONS
  Our meta-analysis confirmed the importance of the presence of iceA for peptic ulcer, although the significance was marginal.
authors.affiliation: Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Hasama-machi, Yufu-City, Oita, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiota
authors.forename: Masahide
authors.initials: M
authors.lastname: Watada
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsunari
authors.forename: Shun
authors.initials: S
authors.lastname: Iwatani
authors.forename: Rumiko
authors.initials: R
authors.lastname: Suzuki
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D016022:Case-Control Studies; D004381:Duodenal Ulcer / Q000150:complications; D005756:Gastritis / Q000150:complications; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D010437:Peptic Ulcer / Q000150:complications; D011379:Prognosis; D013274:Stomach Neoplasms / Q000150:complications
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C408644:IceA2 protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C405087:iceA1 protein, Helicobacter pylori