title: Relevance of high virulence Helicobacter pylori strains and futility of CDX2 expression for predicting intestinal metaplasia after eradication of infection.
abstract: OBJECTIVE
  Different Helicobacter pylori genotypes are associated with distinct inflammatory responses and consequent development of pre-neoplastic lesions, namely intestinal metaplasia (IM), which is dependent on the expression of CDX2. We aimed to evaluate IM progression/regression in the context of H. pylori eradication, bringing into play the effect of the virulence of infecting H. pylori strains and the hypothesis that CDX2 expression might be a marker for later development of IM.
  
  
  METHODS
  Sixty-five male volunteers were evaluated by endoscopy before H. pylori eradication and after a median six-year follow-up. Histological diagnosis was performed at baseline and follow-up, and baseline H. pylori genotypes and CDX2 expression in non-metaplastic foci were also assessed.
  
  
  RESULTS
  Fifty-one individuals remained free from infection at follow-up. Six out of 27 who had no metaplastic lesions at baseline developed IM. CDX2 nuclear expression was observed in 15 of the 21 cases (71.4%) showing no progression to IM, and in three out of six cases (50%) with progression to IM (p = 0.367). Six of the 24 cases with IM at baseline showed regression to less severe outcomes, which was less frequent in those infected with high-virulence strains (7.7% vs. 50%, p = 0.047). In the latter there is a significant persistence of lymphoid follicles.
  
  
  CONCLUSIONS
  Our results support that under infection with high virulence H. pylori strains, IM is a point of difficult return in the gastric carcinogenic pathway. The appearance of CDX-expressing cells in non-metaplastic foci was not associated with the development of IM during the six-year follow-up.
authors.affiliation: Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal. rbarros@ipatimup.pt
authors.forename: Rita
authors.initials: R
authors.lastname: Barros
authors.forename: Bárbara
authors.initials: B
authors.lastname: Peleteiro
authors.forename: Raquel
authors.initials: R
authors.lastname: Almeida
authors.forename: Céu
authors.initials: C
authors.lastname: Figueiredo
authors.forename: Henrique
authors.initials: H
authors.lastname: Barros
authors.forename: Leonor
authors.initials: L
authors.lastname: David
authors.forename: Nuno
authors.initials: N
authors.lastname: Lunet
mesh_terms: D000328:Adult; D000071616:CDX2 Transcription Factor; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D016481:Helicobacter Infections / Q000150:complications* / Q000821:virology*; D016480:Helicobacter pylori / Q000821:virology*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007422:Intestines / Q000473:pathology*; D008297:Male; D008679:Metaplasia / Q000821:virology; D008875:Middle Aged
chemical_list: D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins