Relevance of high virulence Helicobacter pylori strains and futility of CDX2 expression for predicting intestinal metaplasia after eradication of infection.
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.
Barros
Rita
R
Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal. rbarros@ipatimup.pt
Peleteiro
Bárbara
B
Almeida
Raquel
R
Figueiredo
Céu
C
Barros
Henrique
H
David
Leonor
L
Lunet
Nuno
N
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
D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins