Helicobacter pylori Genotypes Are Associated with Clinical Outcome in Portuguese Patients and Show a High Prevalence of Infections with Multiple Strains

Abstract

vacA s1 and cagA+ H. pylori strains are associated with duodenal ulcer, gastric ulcer or gastric carcinoma. vacA m1 is associated with gastric ulcer or carcinoma but not with duodenal ulcer. Infection with multiple H. pylori strains is remarkably high in Portugal and is more frequent in duodenal ulcer patients.

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

“…Van Doorn et al established that in the Iberian Peninsula subtype s1b was the dominant one [24,44,45]. By the contrary, our study demonstrates that in the central region s2 is the more common allele followed by s1a.…”

“…In our study, population iceA2 subtype was the dominant one, as previously stated for Western patients [7,11,20,22]. The relationship of iceA with gastric histopathology and clinical presentation is also very different from study to study [13,20,45]. In our work, we did not find any specific association of iceA allelic variants with pathological or clinical phenotype.…”

“…In our work, we did not find any specific association of iceA allelic variants with pathological or clinical phenotype. Another study, involving patients from the northern region of the country, also failed to found a relation between the iceA allelic variants and clinical outcome of H. pylori infection [45].…”

“…Previous studies in Portugal revealed a high prevalence of patients harboring multiple H. pylori strains [5,21,45]. However, for correlation of H. pylori genotypes with gastric histopathology, most authors exclude patients with multiple isolates.…”

IL1RN polymorphic gene and cagA‐positive status independently increase the risk of noncardia gastric carcinoma

“…The H. pylori virulence marker displaced the importance of some host interleukin polymorphisms in the gastric carcinogenesis when it was included in the logistic regression models. Along with the extremely high prevalence of cagApositive strains in the Asian population, [34][35][36] which mathematically adjusts the statistics for this factor, the lack of a logistic analysis including the cagA status may also have contributed to the differences among the studies, since the prevalence of infection by cagA-positive strains in the previously studied Caucasian populations 37,38 is similar to that seen in our population. 6 The results of this study consequently encourage others to include the cagA status in logistic regression analysis in the studies in their own populations.…”