Immunohistochemical diagnosis of the cagA-gene genotype of Helicobacter pylori with anti-East Asian CagA-specific antibody
Immunohistochemical diagnosis of the cagA-gene genotype of Helicobacter pylori with anti-East Asian CagA-specific antibody
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DOI：
10.1111/j.1349-7006.2007.00415.x
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发表时间：
2007-04-01
期刊：
影响因子：
5.7
通讯作者：
Moriyama, Masatsugu
中科院分区：
文献类型：
--
作者：
Uchida, Tomohisa;Kanada, Ryoko;Moriyama, Masatsugu
幽门螺杆菌产生的细胞毒素相关抗原 A (CagA) 蛋白被认为与胃癌、胃炎和胃十二指肠溃疡的发病机制有关。据报道，胃癌死亡率较高的东亚国家广泛存在的幽门螺杆菌CagA与胃癌死亡率相对较低的西方国家的CagA结构不同。在本研究中，我们生成了一种抗体，即东亚 CagA 特异性抗体 (alpha-EAS Ab)，它与东亚 CagA 发生特异性免疫反应，但与西方 CagA 不发生免疫反应。免疫组织化学检测胃粘膜表面的CagA。有趣的是，在受感染的胃上皮的细胞核和细胞质中也检测到阳性免疫反应性，这表明CagA可能在细胞核和细胞质中发挥一定的致病作用。 47例胃活检标本免疫组化检测出东亚CagA阳性43例幽门螺杆菌。在检查的47例中有46例中，免疫组化获得的数据与分离株cagA基因测序获得的数据完全一致，表明我们的免疫组化方法对于cagA基因型的诊断是可靠且有用的。
Cytotoxin-associated antigen A (CagA) protein produced by Helicobacter pylori is proposed to be associated with the pathogenesis of gastric cancer as well as gastritis and gastroduodenal ulcer. It has been reported that the CagA of H. pylori widespread in East Asian countries, where the mortality rate due to gastric cancer is high, is structurally different from that in Western countries, where the gastric cancer mortality rate is relatively low. In this study, we generated an antibody, East Asian CagA-specific antibody (alpha-EAS Ab), which is specifically immunoreactive with East Asian CagA but not with Western CagA. The CagA was immunohistochemically detected at the surface of the gastric mucosa. Interestingly, positive immunoreactivity was also detected in the nucleus and cytoplasm of the infected gastric epithelium, suggesting that CagA may play some pathogenic role in both the nucleus and cytoplasm. Immunohistochemistry of 47 gastric biopsy specimens detected East Asian CagA-positive H. pylori in 43 cases. In 46 of the 47 cases examined, the data obtained by immunohistochemistry were completely consistent with those obtained by sequencing of the cagA gene of the isolated strain, suggesting that our immunohistochemical method is reliable and useful for diagnosis of the cagA genotype.