幽门螺杆菌cagA基因与胃粘膜损伤及增殖间关系的探讨

The Inter-relationship between the cagA gene of Helicobacter pylori and the gastric mucosal damage, the gastric cell proliferation

目的：探讨幽门螺杆菌（Ｈｐ）细胞毒素相关蛋白基因（ｃａｇＡ基因）与胃粘膜损伤及增殖的关系。方法：采用聚合酶链反应（ＰＣＲ）法检测５０例患者Ｈｐ的ｃａｇＡ基因，并经ＨＥ染色评定胃粘膜炎症程度、肠化生、淋巴小结及萎缩的发生率，免疫组化检测胃粘膜细胞核增殖抗原指数（ＰＣＮＡ ＬＩ％）。结果：３７／５０例含有ｃａｇＡ基因，消化性溃疡ｃａｇＡ基因阳性率高于慢性胃炎（Ｐ＜０．０１）；ｃａｇＡ基因阳性者炎症程度和ＰＣＮＡ ＬＩ％均高于阴性者（Ｐ ＜０．０５）；但两组肠化生﹑淋巴小结及萎缩发生率差异无显著性（Ｐ ＞０．０５）。结论：ｃａｇＡ基因阳性Ｈｐ感染后可增加胃粘膜的炎性损伤及细胞增殖。ｃａｇＡ基因为Ｈｐ毒力指标之一，但并非致病的单一指标。

Objective: To investigate the inter-relationship between the cagA gene of Helicobacter pylori and the gastric mucosal damage, the gastric cell proliferation. Methods: The cytotoxin-associated gene (cagA) was detected by polymerase chain reaction in fifty patients infected with Helicobacter pylori. We investigated the degree of the gastric mucosal inflammation ,the prevalence of intestinal metaplasia,lymphoid follicles,atrophy and the gastric cell proliferation activity of all these patients. Results: Thirty-seven of the patients were cagA positive and thirteen of them were cagA negative.The positive rate of cagA gene in peptic ulcer patients was higher than that in chronic gastritis patients(P <0.01). Individuals with cagA+ strains had significantly higher degree of gastric mucosal inflammation and gastric mucosal proliferation cell nuclear antigen labeling indices (PCNA LI)than persons infected with cagA- strains(P <0.05).There were no significant differences in the prevalence of intestinal metaplasia,lymphoid follicles and atrophy(P >0.05). Conclusion: The cagA gene is one of the toxic items of Helicobacter pylori,but not the only element leading to the gastrointestinal disease.