Studies on the host related factors determining clinical manifestation of the Helicobacter pylori infection among patients with various ethnic backgrounds.

世界上有20多亿人口，日本有6000多万人感染幽门螺杆菌（H.pylori）。大量的资金也投入到治疗和预防与幽门螺杆菌感染有关的疾病上。并非所有感染的患者都会发展为消化性溃疡、恶性肿瘤或胃癌等疾病。致病机制解释为什么有限的亚群患者发展这些疾病尚不清楚。据报道，在亚洲国家，不同种族背景的人群中，这种感染的血清阳性率、疾病谱系和临床结果存在差异，这不能仅仅用所感染病原体的遗传差异或这些国家社会经济和社会卫生水平的差异来解释。宿主相关因素也应该决定感染的临床结果，这些因素大多是未知的。为了积累更多的临床资料和研究发病机制，我们与日本和国外的研究人员建立了合作关系。我们已经从利用人类临床样本和动物疾病模型的研究中获得了一些发现。1、除了幽门螺杆菌与胃上皮相互作用产生的炎症介质外，宿主粘膜免疫系统包括唾液腺和GALT（肠道相关淋巴组织）也在胃炎的组织学表现中起重要作用。我们发现了马来西亚和日本不同种族人群血液中幽门螺杆菌抗体的血清阳性率和谱的差异。这可能解释了研究组之间胃癌发病率和感染临床表现的差异。与捷克调查人员进行了合作。通过对捷克幽门螺杆菌感染患者的多参数分析，发现幽门螺杆菌感染与胃癌家族史、胃氨分泌水平和组织学胃炎分级之间存在相关性。少

Huge population in the world, more than two billions, and more than sixty millions of people in Japan are infected with Helicobacter pylori (H.pylori). Huge sum of money is also invested for the treatment as well as prevention of the diseases related to H.pylori infection. Not all of the patients with this infection develop such diseases as peptic ulcers, MALTOMAs or gastric cancers. The pathogenic mechanisms explaining why limited subgroups of the patients develop these diseases are not understood. The differences in seroprevalence, disease spectrum and clinical outcome of this infection among the population with various ethnic background has been reported in Asian countries, which cannot be explained solely by genetical differences of the pathogen infected or by thedifferences in the socioeconomic as well as social sanitation levels in these countries. The host related factors should also determine clinical outcome of the infection, which are mostly unknown. In order to accumulate cl … More inical data and to study mechanisms of pathogenesis, we have established collaboration among investigators in Japan and abroad. We have obtained several findings out ofstudies utilizing human clinical samples and animal disease models.1, Not only the inflammatory mediators produced by the interaction between H.pylori and gastric epithelia, the host mucosal immune system including salivary glands and GALT (gut associated lymphoid tissue) also play important roles for the histological manifestation of the gastritis.2, We found differences in seroprevalence and profiles of antibodies to H.pylori in the blood among different ethnic groups in Malaysia and Japanese. This may explain different rate of incidence of gastric cancer and differences in clinical manifestation of the infection among study groups.3. Collaboration with investigators in Czech was carried out. Multiple parametric analyses in the patients with H.pylori infection in Czech revealed correlation among presence of H.pylori infection, family history of gastric cancer, level of ammonia produced in the stomach and grade of histological gastritis. Less