广州地区消化道疾病患者中H.pylori ureA和vacA s1基因及cagA基因亚型分布

目的 分析研究广州地区消化道疾病患者中H.pylori ureA、vacA s1基因和cagA基因亚型(ABC、ABD、ABAB、AAD等)的分布状况及其与胃黏膜病理检测结果间的相关性.方法 随机选取227例消化道疾病患者的胃黏膜标本,分别来自病理组织学检测无病理改变者46例,慢性胃炎130例,消化性溃疡29例,萎缩性胃炎15例,胃癌7例.并用实时荧光定量PCR检测H.pylori ureA基因、vacA s1基因,用PCR扩增cagA羧基端EPIYA基序所在区,然后测序确定其亚型.以保守基因ureA的存在判断H.pylori感染.结果 227例消化道疾病患者中,有50.7% (115/227)的患者H.pylori阳性,其中,vacA s1基因阳性91.3%(105/115),cagA基因阳性78.3%(90/115).4种cagA-EPIYA亚型分布为,ABC 17.8%(16/90)、ABD 78.9%(71/90)、AAD 2.2%(2/90)、ABAB 1.1%(1/90).无病理改变组中H.pylori 阳性32.6%(15/46),vacA s1基因阳性28.3%(13/46),cagA基因阳性26.1%(12/46);慢性胃炎组H.pylori 阳性48.5%(63/130),vacA s1基因阳性43.8%(57/130),cagA基因阳性36.2%(47/130);溃疡组H.pylori 阳性72.4%(21/29),vacA s1基因阳性65.5%(19/29),cagA基因阳性55.2%(16/29);萎缩性胃炎组H.pylori 阳性66.7%(10/15),vacA s1基因阳性66.7%(10/15),cagA基因阳性66.7%(10/15);胃癌组H.pylori阳性85.7%(6/7),vacA s1基因阳性85.7%(6/7),cagA基因阳性71.4%(5/7).H.pylori在不同胃黏膜病理组的分布差异有统计学意义(χ2=16.72;P<0.01),溃疡、萎缩性胃炎、胃癌组中H.pylori的分布明显高于无病理改变与炎症组(χ2=16.02;P<0.01).但在H.pylori阳性患者中,强毒力因子vacA s1基因(χ2=2.00;P=0.74)、cagA基因(χ2=3.44;P=0.49)及cagA-EPIYA亚型(χ2=3.66;P=0.45)在无病理改变、炎症、溃疡、萎缩性胃炎及胃癌组中的分布差异均无统计学意义.结论 广州消化道疾病患者中H.pylori的感染与胃黏膜病理改变显著相关,而广州地区消化道疾病患者中H.pylori高毒力亚型的强致病性并不明显,需扩大标本量,再细化疾病种类进一步分析高毒力H.pylori对胃肠道疾病发生的影响.

Abstract：

Objective To detect the distribution of H.pylori ureA, vacA s1 gene and cagA subtype(ABC, ABD, ABAB, AAD, et al) in patients with digestive diseases in Guangzhou and investigate the relationship with the pathological findings of gastric mucosa.Methods A total of 227 randomly selected gastric mucosa from patients with digestive diseases were enrolled in the research, including 46 without pathological changes, 130 with chronic gastritis, 29 with peptic ulcer, 15 with atrophic gastritis and 7 with gastric cancer.Real-time PCR assay were used to detect Helicobacter pylori ureA gene and vacA s1 gene.EPIYA motifs in the 3′ region of cagA were amplified by conventional PCR followed by subtype sequencing. The conserved gene ureA was used to detect H.pylori infection.Results Among the 227 patients with digestive diseases, 50.7% (115/227) patients were H.pylori positive, in which 91.3%(105/115) carried vacA s1 and 78.3% (90/115) carried cagA. Four types of cagA-EPIYA subtype were detected, including ABC 17.8%(16/90), ABD 78.9%(71/90), AAD 2.2%(2/90) and ABAB 1.1%(1/90).In the non-pathological change group, 32.6% (15/46) were H.pylori positive, in which 28.3% (13/46) carried vacA s1 and 26.1% (12/46) carried cagA;in chronic gastritis group, it was 48.5% (63/130), 43.8% (57/130) and 36.2% (47/130), respectively;in ulcer group, it was 72.4% (21/29), 65.5% (19/29) and 55.2% (16/29), respectively;in atrophic gastritis group, it was 66.7% (10/15), 66.7% (10/15) and 66.7% (10/15), respectively;in gastric cancer group, it was 85.7% (6/7), 85.7% (6/7) and 71.4% (5/7), respectively.The distribution of H.pylori among the 4 groups had statistical significance (χ2=16.72;P<0.01). H.pylori was more prevalent in ulcer, atrophic gastritis and cancer group than in inflammation group and non-pathological change group (χ2=16.02;P<0.01).In patients infected by H.pylori, there was no significant difference in the distribution of vacA s1 gene as high virulence factors among non-pathological change, inflammation, ulcer, atrophic gastritis and cancer group (χ2=2.00;P=0.74), as well as cagA (χ2=3.44;P=0.49) and EPIYA subtypes (χ2=3.66;P=0.45).Conclusions H.pylori infection is significantly associated with the pathological change of gastric mucosa for patients with digestive diseases in Guangzhou, while the relationship with the pathogenicity of H.pylori with high virulence genotype is not significant.More samples and diseases reclassification are needed to make an advanced analysis of the effect of H.pylori with high virulence in gastrointestinal diseases development.

Clinical research of the distribution of H.pylori ureA, vacA s1 gene and cagA subtype distribution in patients with digestive diseases in Guangzhou

Objective To detect the distribution of H.pylori ureA, vacA s1 gene and cagA subtype(ABC, ABD, ABAB, AAD, et al) in patients with digestive diseases in Guangzhou and investigate the relationship with the pathological findings of gastric mucosa.Methods A total of 227 randomly selected gastric mucosa from patients with digestive diseases were enrolled in the research, including 46 without pathological changes, 130 with chronic gastritis, 29 with peptic ulcer, 15 with atrophic gastritis and 7 with gastric cancer.Real-time PCR assay were used to detect Helicobacter pylori ureA gene and vacA s1 gene.EPIYA motifs in the 3′ region of cagA were amplified by conventional PCR followed by subtype sequencing. The conserved gene ureA was used to detect H.pylori infection.Results Among the 227 patients with digestive diseases, 50.7% (115/227) patients were H.pylori positive, in which 91.3%(105/115) carried vacA s1 and 78.3% (90/115) carried cagA. Four types of cagA-EPIYA subtype were detected, including ABC 17.8%(16/90), ABD 78.9%(71/90), AAD 2.2%(2/90) and ABAB 1.1%(1/90).In the non-pathological change group, 32.6% (15/46) were H.pylori positive, in which 28.3% (13/46) carried vacA s1 and 26.1% (12/46) carried cagA;in chronic gastritis group, it was 48.5% (63/130), 43.8% (57/130) and 36.2% (47/130), respectively;in ulcer group, it was 72.4% (21/29), 65.5% (19/29) and 55.2% (16/29), respectively;in atrophic gastritis group, it was 66.7% (10/15), 66.7% (10/15) and 66.7% (10/15), respectively;in gastric cancer group, it was 85.7% (6/7), 85.7% (6/7) and 71.4% (5/7), respectively.The distribution of H.pylori among the 4 groups had statistical significance (χ2=16.72;P<0.01). H.pylori was more prevalent in ulcer, atrophic gastritis and cancer group than in inflammation group and non-pathological change group (χ2=16.02;P<0.01).In patients infected by H.pylori, there was no significant difference in the distribution of vacA s1 gene as high virulence factors among non-pathological change, inflammation, ulcer, atrophic gastritis and cancer group (χ2=2.00;P=0.74), as well as cagA (χ2=3.44;P=0.49) and EPIYA subtypes (χ2=3.66;P=0.45).Conclusions H.pylori infection is significantly associated with the pathological change of gastric mucosa for patients with digestive diseases in Guangzhou, while the relationship with the pathogenicity of H.pylori with high virulence genotype is not significant.More samples and diseases reclassification are needed to make an advanced analysis of the effect of H.pylori with high virulence in gastrointestinal diseases development.