Helicobacter pylori Genotypes May Determine Gastric Histopathology

Abstract

The outcome of Helicobacter pylori infection has been associated with specific virulence-associated bacterial genotypes. The present study aimed to investigate the gastric histopathology in Portuguese and Colombian patients infected with H. pylori and to assess its relationship with bacterial virulence-associated vacA, cagA, and iceA genotypes. A total of 370 patients from Portugal (n = 192) and Colombia (n = 178) were studied. Corpus and antrum biopsy specimens were collected from each individual. Histopathological features were recorded and graded according to the updated Sydney system. H. pylori vacA, cagA, and iceA genes were directly genotyped in the gastric biopsy specimens by polymerase chain reaction and reverse hybridization. Despite the significant differences between the Portuguese and Colombian patient groups, highly similar results were observed with respect to the relation between H. pylori genotypes and histopathology. H. pylori vacA s1, vacA m1, cagA+ genotypes were significantly associated with a higher H. pylori density, higher degrees of lymphocytic and neutrophilic infiltrates, atrophy, the type of intestinal metaplasia, and presence of epithelial damage. The iceA1 genotype was only associated with epithelial damage in Portuguese patients. These findings show that distinct H. pylori genotypes are strongly associated with histopathological findings in the stomach, confirming their relevance for the development of H. pylori-associated gastric pathology.

Correlation of Helicobacter pylori Genotypes with Gastric Histopathology in the Central Region of a South-European Country

“…In our study cagA genotype, albeit determined by real-time PCR using two different sets of primers, was identified in only 31.8 % of isolates. This is considerably less than it was previously published for our country [5,30]. There are different possible explanations for this finding.…”

“…By the contrary, our study demonstrates that in the central region s2 is the more common allele followed by s1a. It is known that vacA s1m1 strains determine higher levels of inflammation in the gastric mucosa and both vacA s1m1 and s1m2 strains may be disease-associated but patients with gastric cancer usually have the s1m1 type [5,10,28,39,44,46]. In our population, we found no correlations of vacA genotypes with gastric histopathological modifications.…”

“…There is a geographic variability of H. pylori genotypes [20,24]. Patients infected with more virulent strains have higher probabilities of developing complications [5]. Conclusions about the relation between H. pylori genotypes and different clinical outcomes, if derived from a single geographic region, may not be true for other geographic locations [19].…”

“…Infection generally occurs during childhood and development of more severe histopathological manifestations, such as intestinal metaplasia and glandular atrophy, are linked to prolonged infection and consequently to patients' age [25,26]. A study performed in the northern part of the country also revealed that patients with atrophic gastritis were significantly older than the ones with no atrophy [5].…”

“…The cagA gene (cytotoxinassociated gene) is a marker of the pathogenicity island gene (cagPAI) presence. Infection with cagA-positive strains is associated with a greater inflammatory response and an increased risk of adverse clinical outcomes including atrophic gastritis and gastric cancer [5,6]. cagE is another marker gene for cagPAI and has also been associated with a more severe clinical outcome by stimulating the production of several cytokines from infected epithelial cells [7].…”