上海崇明地区幽门螺杆菌cagA基因多态性与感染临床结局的关系

目的探讨上海崇明地区幽门螺杆菌（Helicobacter pylori，Hp）的cagA基因的多态性与感染临床结局的关系。方法采用PCR法检测100株临床分离株cagA基因亚型，获得东亚型和西方型2种基因型。分析cagA基因亚型与消化道疾病间的关系。结果100株Hp中72株检出cagA基因，其中81．9％为cagA基因东亚型，15．3％为西方型，2．8％为同时存在着2种基因型。胃癌与慢性萎缩性胃炎患者中cagA基因东亚型菌株均显著高于胃溃疡、十二指肠溃疡患者，而十二指肠溃疡cagA基因西方型菌株的比率显著高于其余4种疾病类型。结论本地区感染Hp以cagA基因东亚型为主，cagA基因东亚型菌株与胃癌、慢性萎缩性胃炎密切相关，而cagA基因西方型菌株与十二指肠溃疡密切相关。推测cagA基因多态性对由Hp引起的感染性疾病的发病机制可能起一定的作用。

The relationship between cagA polymorphisms and clinical outcome of Helicobacter pylori in Chongming, Shanghai

Objective To explore the relationship between cagA polymorphisms and clinical outcome of Helicobacter pylori （Hp） in Chongming, Shanghai. Methods A total of 100 strains of Hp were subject to cagA genotyping by PCR. The prevalence of cagA genotypes and its association with the clinical outcome were analyzed by Chi-square test and Fisher＇s exact proba-bility test. Results The cagA gene was identified in 72 of the 100 Hp strains. Of the 72 strains, 59 （81.9%） were cagA-East Asian genotype, 11 （15.3 %） belonged to cagA-Western genotype, and 2.8 %0 with both cagA-East Asian and cagA-Western genotypes. The prevalence of cagA-East Asian genotype in the patients with chronic atrophic gastritis and gastric cancer was significantly higher than that in the patients with peptic ulcer. The prevalence of cagA-Western genotype in the patients with duodenal ulcer was significantly higher than that in other diseases. Conclusions The cagA-East Asian genotype is the major genotype of cagA gene in Chongming. It is associated with chronic atrophic gastritis and gastric cancer. The cagA-Western genotype is associated with duodenal ulcer. The polymorphisms of cagA gene may play an important role in the pathogenesis of Hp-associated diseases.