幽门螺杆菌CagA与GSTM1缺失对胃癌的交互作用研究

The Interaction of H.Pylori CagA Infection and GSTM1 Null Genotype in Stomach Carcinoma

[目的]探讨幽门螺杆菌CagA感染与胃癌的关系,及其与代谢酶基因多态性的交互作用对胃癌易感性的影响。[方法]以社区为基础的病例对照研究。肠型胃癌病例经胃镜及病理确诊,有效分析样本包括:完成CagA抗体检测胃癌108例,对照217例;完成CagA抗原检测病例107例,对照284例。[结果]胃癌组H.PyloriCagA抗体阴性率为85.19%,显著高于对照组的49.31%,OR值为5.91(95%CI:3.26～10.71,P=0.001);在CagA抗体阴性时,胃癌组CagA抗原阳性率达12.50%,显著高于对照组的1.82%,OR值为7.71(95%CI:1.01～59.18,P=0.023),在CagA抗体阳性组则未见两者有显著性差异;调整混杂因素后,GSTM1缺失基因型与H.PyloriCagA抗原之间有明显的相乘交互作用,γ为19.58,交互作用OReg达10.49,与H.PyloriCagA抗体之间也有明显的交互作用。[结论]H.PyloriCagA毒株感染后产生的CagA抗体是保护性因素,而H.PyloriCagA抗原为胃癌的危险性指标;H.PyloriCagA感染与GSTM1缺失基因型对胃癌发生有明显的交互作用。

To explore the relationship between H.Pylori Cag A infection and the risk of stomach carcino-ma,and their interactions with metabolic genes(CYP1A1and GSTM1).Community-based case-control study de-sign was used.H.Pylori Cag A antibody was measured in108cases with intestinal type of stomach cancer cases and217controls.H.Pylori Cag A antigen was measured in107stomach cancer patients and284controls.Patients were diagnosed by either endoscopy or pathology.It was indicated that H.Pylori CagA antibody negative rate was85.19%,which was significantly higher than that in control(49.31%).OR was5.91(95%CI:3.26～10.71,P=0.001).In Cag A negative group,we found that Cag A antigen positive rate(12.50%)in stomach cancer cases was significantly higher than that in control positive group(1.82%).OR was7.71(95%CI:1.01~59.18,P=0.023).After adjusting confounding factors,a significant multiplicative interaction was displayed between H.Pylori Cag A antigen and GSTM1null genotype.γwas19.58and OR eg was10.49.The same interaction was found between H.Pylori Cag A antibody and GSTM1null genotype.[Conclusions]H.Pylori Cag A antigen is one of the risk biomarkers of predicting stomach carcinoma,and H.Pylori CagA antibody is as one of protective factors.H.Pylori CagA infection has significant interactions with GSTM1null genotype which way in-crease the susceptibility of stomach carcinoma.