Trujillo Esperanza, Martínez Teresa, Bravo María Mercedes
Grupo de Investigación en Cáncer y Agentes Infecciosos, Instituto Nacional de Cancerología, Bogotá, D.C, Colombia.
Grupo de Investigación Epidemiológica del Cáncer, Instituto Nacional de Cancerología, Bogotá, D.C, Colombia.
Biomedica. 2014 Oct-Dec;34(4):567-73. doi: 10.1590/S0120-41572014000400009.
The overall prevalence of Helicobacter pylori infection is high in Colombia; however, in the country´s Andean region, gastric cancer rates far surpass those in coastal areas. Helicobacter pylori genotypes cagA positive and vacA s1 and m1 are associated with an increased risk of gastric cancer.
To compare the distribution of H. pylori genotypes associated with virulence in two regions in Colombia with opposing risk for gastric cancer.
Four hundred and one gastric antral biopsies were obtained and analyzed from 401 individuals diagnosed with non-atrophic gastritis, atrophic gastritis and intestinal metaplasia: 256 came from the high-risk area cities of Tunja and Bogotá, and 145 from the low-risk area cities of Barranquilla, Santa Marta and Cartagena. Genotyping of virulence genes vacA and cagA was performed by PCR.
No difference was observed in the frequency of H. pylori infection between the two areas (77.3% vs 77.9 %, p=non significant, ns). The presence of cagA was higher in the low-risk area (77.9% vs. 69.2 %, p=ns). The vacA s1 allele was also more prevalent in the low-risk area (61.8 % vs 72.0 %, p=ns). The vacA m1 allele was more prevalent in the high-risk area (57.2 % vs 42.8 %, p=ns). The cagA positive s1m1 combination was also more frequent in the low-risk area (48.9% vs 38.9%, p=ns).
The differences in the risk of gastric cancer in these two geographic areas cannot be explained by differences in the prevalence of infection by H. pylori or by differences in the virulence of circulating strains.
幽门螺杆菌感染在哥伦比亚的总体患病率很高；然而，在该国的安第斯地区，胃癌发病率远远超过沿海地区。幽门螺杆菌cagA阳性、vacA s1和m1基因型与胃癌风险增加相关。
比较哥伦比亚两个胃癌风险相反地区与毒力相关的幽门螺杆菌基因型分布。
从401名诊断为非萎缩性胃炎、萎缩性胃炎和肠化生的个体中获取并分析了401份胃窦活检样本：256份来自通哈和波哥大等高危地区城市，145份来自巴兰基亚、圣玛尔塔和卡塔赫纳等低风险地区城市。通过聚合酶链反应对毒力基因vacA和cagA进行基因分型。
两个地区之间幽门螺杆菌感染频率未观察到差异（77.3%对77.9%，p=无显著性差异，ns）。低风险地区cagA的存在率更高（77.9%对69.2%，p=ns）。vacA s1等位基因在低风险地区也更普遍（61.8%对72.0%，p=ns）。vacA m1等位基因在高风险地区更普遍（57.2%对42.8%，p=ns）。cagA阳性s1m1组合在低风险地区也更常见（48.9%对38.9%，p=ns）。
这两个地理区域胃癌风险的差异不能用幽门螺杆菌感染患病率的差异或流行菌株毒力的差异来解释。
