Suzuki Hidekazu, Masaoka Tatsuhiro, Nomura Sachiko, Hoshino Yoshinori, Kurabayashi Kumiko, Minegishi Yuriko, Suzuki Masayuki, Ishii Hiromasa
Department of Internal Medicine, School of Medicine Keio University, Tokyo, Japan.
Keio J Med. 2003 Sep;52(3):163-73. doi: 10.2302/kjm.52.163.
Helicobacter pylori (H. pylori) is a spiral shaped bacterium that resides in the stomach mucosa. Isolation of H. pylori from the stomach mucosa changed the erstwhile widely held belief that the stomach contains no bacteria and is actually sterile. Once H. pylori is safely ensconced in the mucus, it is able to neutralize the acid in the stomach by elaborating an enzyme called urease. Urease converts urea, of which there is an abundant supply in the stomach (derived from saliva and the gastric juice), into bicarbonate and ammonia, which are strong bases. These bases form a cloud of acid-neutralizing chemicals in the vicinity of the organisms, protecting them from the acid in the stomach. This urea hydrolysis reaction is utilized for the diagnosis of H. pylori infection in the urea breath test (UBT) and the rapid urease test (RUT). In Japan, both invasive tests, such as bacterial culture, histopathology and RUT, and non-invasive tests such as UBT and serology are conducted for the diagnosis of H. pylori infection. For confirming the results of eradication therapy, UBT is considered to be the most sensitive and specific. In order to treat H. pylori infection, a new one-week triple therapy regimen (lansoprazole or omeprazole + amoxicillin + clarithromycin) has been approved for use in patients with peptic ulcer disease in Japan. As for H. pylori eradication in the case of other diseases in which the bacterium has been implicated (e.g., chronic atrophic gastritis, gastric MALT lymphoma, gastric cancer, non-ulcer dyspepsia, chronic urticaria, idiopathic thrombocytopenic purpura (ITP)), further basic and clinical investigation is required.
幽门螺杆菌（H. pylori）是一种存在于胃黏膜中的螺旋形细菌。从胃黏膜中分离出幽门螺杆菌改变了过去人们普遍认为胃中没有细菌且实际上是无菌的观念。一旦幽门螺杆菌安全地隐匿于黏液中，它就能通过分泌一种名为尿素酶的酶来中和胃中的酸。尿素酶将胃中大量存在的尿素（来源于唾液和胃液）转化为碳酸氢盐和氨，这两种都是强碱。这些碱在细菌周围形成一层酸中和化学物质云，保护它们免受胃中酸的侵害。这种尿素水解反应被用于尿素呼气试验（UBT）和快速尿素酶试验（RUT）中幽门螺杆菌感染的诊断。在日本，对于幽门螺杆菌感染的诊断，既进行侵入性检查，如细菌培养、组织病理学检查和RUT，也进行非侵入性检查，如UBT和血清学检查。为了确认根除治疗的结果，UBT被认为是最敏感和特异的。为了治疗幽门螺杆菌感染，一种新的一周三联疗法方案（兰索拉唑或奥美拉唑 + 阿莫西林 + 克拉霉素）已被批准用于日本患有消化性溃疡疾病的患者。至于在其他与该细菌有关的疾病（如慢性萎缩性胃炎、胃黏膜相关淋巴组织淋巴瘤、胃癌、非溃疡性消化不良、慢性荨麻疹、特发性血小板减少性紫癜（ITP））中根除幽门螺杆菌，则需要进一步的基础和临床研究。
