幽门螺杆菌vac A基因型与胃癌及癌前病变的相关性

The relationship between vac A genotype of Helicobacter pylori clinical isolate and gastric cancer and precancer

目的 分析胃癌高发的西安地区幽门螺杆菌 (Hp)分离株空泡形成毒素基因 (vacA)的基因型与胃癌及癌前病变的相关性。方法 建立Hp菌株库并采用聚合酶链反应 (PCR)技术进行vacA基因s、m分型。结果 192株菌株中 ,s1型 174株 ,占 90 6 % ;s2型 18株 ,占 9 4%。m1型 99株(5 1 6 % ) ;m2型 93株 (4 8 4% )。所有菌株的PCR产物均为s1或s2 ,m1或m2。s1在胃癌分离株中表达占 94 5 % ,其中s1a型明显多于s1b(P <0 0 5 ) ;但m1和m2表达差异不显著。在胃炎组 ,仍是s1型表达占多数 (89 8% ) ,但s1a和s1b、m1和m2表达的差异无显著性。结论 无论胃癌还是胃炎均以s1型为主 ,且在胃癌组s1a型表达显著高于s1b型 ,它是否是促进胃黏膜恶性变的指标 ,尚需进一步研究。但可肯定西安地区vacA基因型以致病性较强的产毒型为主。

Objective To analyze the relationship between vac A genotype of Helicobacter pylori (Hp)and gastric cancer and precancer in Xi′an area. Methods To establish the stock of Hp clinical isolates and perform vac A gene typing of Hp isolates by PCR. Results 192 Hp clinical strains are isolated from the antrum of 259 patients. In them, type s1 is 174 strains (90.6%); s2 is 18 stains(9.4%). Type m1 and m2 is 99 (51.6%) and 93(48.4%) respectively. All strains are s1 or s2 and m1 or m2. In gastric cancer group, the expression of type s1 is 94.5% and s1a is more than s1b ( P <0.05). There is no difference between type m1 and m2. In gastritis group, type s1 is 89.8%, s1a is almost equal to s1b and no difference between m1 and m2. Conclusion Type s1 is the main expression in both gastric cancer group and gastritis group. Expression of type s1a is higher than s1b. We can′t determine it is a malignant index of gastrointestinal diseases. We need to research it extensively.