The Helicobacter pylori duodenal ulcer promoting gene, dupAin China

Zhiyu Zhang,Xiaoyu Chen,Qing Zheng,Wenzhong Liu,Shudong Xiao,Hong Lu

doi:10.1186/1471-230x-8-49

Abstract

BackgroundThe prevalence of H. pylori is as high as 60–70% in Chinese population. Although duodenal ulcer and gastric cancer are both caused by H. pylori, they are at opposite ends of the spectrum and as such are considered mutually exclusive. Duodenal ulcer promoting (dupA) gene was reported to be associated with duodenal ulcer development. The aim of this study was to determine the prevalence of dupA gene of Helicobacter pylori in patients with various gastroduodenal diseases and to explore the association between the gene and other virulence factors.MethodsH. pylori were isolated from gastric biopsies of patients with chronic gastritis, duodenal ulcer (DU), gastric ulcer (GU), or non-cardia gastric carcinoma. The dupA, cagA, vacA, iceA and babA2 genotypes were determined by polymerase chain reaction. Histological features of gastric mucosal biopsy specimens were graded based on the scoring system proposed by the updated Sydney system. IL-1β polymorphism was investigated using restriction fragment length polymorphism.ResultsIsolates from 360 patients including 133 with chronic gastritis, 101 with DU, 47 with GU, and 79 with non-cardia gastric carcinoma were examined. The dupA gene was detected in 35.3% (127/360) and the prevalence DU patients was significantly greater than that in gastric cancer or GU patients (45.5% vs. 24.1% and 23.4%, P < 0.05). Patients infected with dupA-positive strains had higher scores for chronic inflammation compared to those with dupA-negative strains (2.36 vs. 2.24, p = 0.058). The presence of dupA was not associated with the cagA, vacA, iceA and babA 2 genotypes or with IL-1β polymorphisms.ConclusionIn China the prevalence of dupA gene was highest in DU and inversely related to GU and gastric cancer.

Highlights

The prevalence of H. pylori is as high as 60–70% in Chinese population
In China the prevalence of dupA gene was highest in duodenal ulcer (DU) and inversely related to gastric ulcer (GU) and gastric cancer
The proportion of men was higher in the GU than in other three groups (p = 0.03) and the mean age of the patients with DU was lower than those with GU gastric cancer or gastritis (p = 0.03) (Table 2)

Summary

Introduction

The prevalence of H. pylori is as high as 60–70% in Chinese population. duodenal ulcer and gastric cancer are both caused by H. pylori, they are at opposite ends of the spectrum and as such are considered mutually exclusive. BMC Gastroenterology 2008, 8:49 http://www.biomedcentral.com/1471-230X/8/49 tric cancer) Several virulence factors such as the cag pathogenicity island, vacA, oipA and babA have been described and have been associated with an increase in the risk of both gastric cancer and duodenal ulcer disease [1,2,3,4]. The associations between the cag pathogenicity island, vacA, oipA and babA and enhanced mucosal inflammation, gastric cancer and peptic ulcer were identified and confirmed in Western countries where there is considerable strain diversity [5,6,7,8,9]. Polymorphism of interleukin-1β was reported to be an important host factor that increases the risk gastric cancer [10,11]

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