Department of Gastroenterology, University of São Paulo School of Medicine, Av Dr Enéas de Carvalho Aguiar 255, 9 degrees andar sala 9159, São Paulo, 05403-000, SP, Brazil.
Infect Agent Cancer. 2010 Jan 11;5:1. doi: 10.1186/1750-9378-5-1.
H. pylori seroprevalence in Brazilians varies and is dependent on socioeconomic status, sanitation conditions and ethnicity; furthermore, H. pylori is not always associated with the incidence of gastric cancer, suggesting the role of more virulent strains. The purpose of this study was to analyze the association of more virulent H. pylori strains with gastric cancer.
DNA was extracted from gastric biopsies of thirty-four cases of gastric cancer (11 intestinal-type, 23 diffuse-type), and thirty-four of patients with endoscopic gastritis. The presence of cagPAI genes (cagA, cagA promoter, cagE, cagM, tnpB, tnpA, cagT and the left end of the cagII (LEC)) and babA were analyzed by PCR.
Comparison of H. pylori isolates from gastric cancer and gastritis patients showed significant associations of tnpA and LEC with gastric cancer (73.5% [OR, 6.66; 95% CI, 2.30-19.25] and 58.8% [OR, 10.71; 95% CI, 3.07-37.28] of cases, respectively). Other cagPAI genes were detected in both groups at similar frequencies.
tnpA and LEC of H. pylori cagPAI were associated with gastric cancer; nonetheless, these results were restricted within this group of patients and further studies are needed to confirm these results in a larger sample and determine their role in gastric carcinogenesis.
巴西的 H. pylori 血清流行率因社会经济地位、卫生条件和种族而异；此外，H. pylori 并不总是与胃癌的发生相关，这表明存在更具毒性的菌株。本研究旨在分析更具毒性的 H. pylori 菌株与胃癌之间的关联。
从 34 例胃癌（11 例肠型，23 例弥漫型）和 34 例内镜胃炎患者的胃活检组织中提取 DNA。采用 PCR 方法分析 cagPAI 基因（cagA、cagA 启动子、cagE、cagM、tnpB、tnpA、cagT 和 cagII 左末端（LEC））和 babA 的存在情况。
比较胃癌和胃炎患者的 H. pylori 分离株，tnpA 和 LEC 与胃癌显著相关（分别为 73.5%[OR，6.66；95%CI，2.30-19.25]和 58.8%[OR，10.71；95%CI，3.07-37.28]）。两组中均以相似的频率检测到其他 cagPAI 基因。
H. pylori cagPAI 的 tnpA 和 LEC 与胃癌相关；然而，这些结果仅限于这组患者，需要进一步的研究来在更大的样本中证实这些结果，并确定它们在胃癌发生中的作用。
