Siavoshi Farideh, Malekzadeh Reza, Daneshmand Mohammad, Ashktorab Hassan
Department of Cell and Molecular Biology, Khatam University, Tehran.
Dig Dis Sci. 2005 Nov;50(11):2075-80. doi: 10.1007/s10620-005-3010-1.
H. pylori infection of the stomach is widespread among human populations including Iranians and is considered to play a major role in the pathogenesis of gastric diseases such as peptic ulcer, adenocarcinoma, and MALT lymphoma. The association between H. pylorivirulence markers and disease has been studied in other populations around the world. The aim of this study was to investigate the distribution of H. pylori vacA and cagA genotypes and their association with clinical outcomes in Iran. H. pylori was cultured from gastric biopsy specimens obtained from 137 Iranian patients (58 with duodenal ulcer, 61 with nonulcer dyspeptic [NUD], and 18 with gastric adenocarcinoma). The vacA alleles and cagA genotypes were determined by PCR. The vacA sl allele was present in 107 of the 137 subjects (78%). Multiple strains (m1 and m2) were detected in H. pylori isolates from the patients. VacA s1 genotypes were more frequent in patients with peptic ulcer (46/58; 79%) than in NUD patients (47/61; 77%). CagA was present in 44% of the patients. NUD patients had a frequency of cagA positivity similar to that of the overall population (46%). CagA was present more frequently more than cagA-negative (20% vs. 8%, respectively) in patients with gastric carcinoma (20%) than cagA-negative in patients with gastric carcinoma (8%). This is the first comprehensive study to demonstrate the frequency of colonization with mixed strain, vacA s1, m1 and m2 as the dominant genotype in these Iranian patients, where a high rate of H. pylori infection exists and is similar to the region with a low rate of H. pylori infection. Therefore, host genetics, environmental factors, and the substantial genetic heterogeneity among different H. pylori strains may contribute to the different clinical outcomes.
幽门螺杆菌胃部感染在包括伊朗人在内的人群中广泛存在，并且被认为在诸如消化性溃疡、腺癌和黏膜相关淋巴组织淋巴瘤等胃部疾病的发病机制中起主要作用。幽门螺杆菌毒力标志物与疾病之间的关联已在世界其他人群中进行了研究。本研究的目的是调查伊朗幽门螺杆菌vacA和cagA基因型的分布及其与临床结局的关联。从137名伊朗患者（58例十二指肠溃疡患者、61例非溃疡性消化不良[NUD]患者和18例胃腺癌患者）的胃活检标本中培养幽门螺杆菌。通过聚合酶链反应（PCR）确定vacA等位基因和cagA基因型。137名受试者中有107名（78%）存在vacA s1等位基因。在患者的幽门螺杆菌分离株中检测到多种菌株（m1和m2）。消化性溃疡患者中VacA s1基因型（46/58；79%）比NUD患者（47/61；77%）更常见。44%的患者存在CagA。NUD患者的CagA阳性频率与总体人群相似（46%）。胃癌患者中CagA阳性的频率（20%）比CagA阴性的频率（8%）更高。这是第一项全面研究，证明在这些伊朗患者中混合菌株、vacA s1、m1和m2作为主要基因型的定植频率，该地区幽门螺杆菌感染率高，与幽门螺杆菌感染率低的地区相似。因此，宿主遗传学、环境因素以及不同幽门螺杆菌菌株之间的大量遗传异质性可能导致不同的临床结局。
