Role of heat-shock protein (HSP) 70-2 genotype in peptic ulcer in Japanese population.

Background/Aims: There have been reports showing the protective role of inducible Heat-shock protein (HSP) 70 in gastric epithelial cells. An A to G transition at the 1267 position HSP70-2 gene has been shown to be associated with a different level of HSP70 mRNA expression. We aimed to clarify the effect of HSP70-2 polymorphism on the risk of peptic ulcer diseases in a Japanese population. Methodology: A total of 519 subjects participated in this study. All subjects underwent upper gastroscopy. Restriction fragment length polymorphism analysis was performed for polymorphisms at 1267 of HSP70-2 gene in all the subjects. Results: After gastroscopy, 109, 53 and 357 subjects were diagnosed as gastric ulcer, duodenal ulcer and non-ulcer subjects, respectively. Although, there were no significant differences of HSP70-2 genotype distributions among non-ulcer subjects, overall ulcer, gastric and duodenal ulcers when the subjects were divided into two groups according to age distribution, logistic regression analysis showed that the BB genotype increased the risk of duodenal ulcer in subjects 60 years and older. (Gender, status of H. pylori infection and NSAID use adjusted OR=3.12, 95%CI=1.33-7.35, p=0.009). Conclusions: It appears that polymorphism of HSP70-2 gene is not directly associated with the susceptibility to peptic ulcer diseases but BB genotype is associated with an increased risk of duodenal ulcer in older subjects in the Japanese population.