Association of Helicobacter pylori with gastroduodenal diseases

Helicobacter pylori was first cultured in vitro in 1982. This bacterium is a spiral gram-negative rod which grows under microaerophilic conditions. The ecological niche is the mucosa of the human stomach which had been thought to be aseptic before the discovery of this bacterium. This organism causes a long-lasting infection throughout a person's life if there is no medical intervention. Numerous persons are infected with the organism around the world, and the rate of infection in Japan is nearly 50% of the population. However, the route of infection remains unclear because the organism has not been isolated from any environment other than several animals. H. pylori is now recognized as a causative agent of gastritis and peptic ulcers. Though gastritis, and especially chronic active gastritis, is observed at least histologically in all persons with H. pylori, peptic ulcers develop in only some infected persons. Specific factors in the host and/or the bacteria are needed for the development of peptic ulcer disease. Furthermore, H. pylori is considered to be related to the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma, especially those of low grade. Also, H. pylori infection is a major determinant for initiating the sequence of events leading to gastric cancer. In some patients with low-grade gastric MALT lymphoma, the eradication of H. pylori led to a regression of lesion. Gastric cancer has been induced in Mongolian gerbils with long-term H. pylori infection. The combinations of drugs, which consist of an antisecretory agent (acid-suppressing agent) and antimicrobial agents, are used for the eradication of the organism. Eradication therapy is recommended at least for patients with peptic ulcers.     

幽门螺杆菌感染与上胃肠道疾病

1982年Marshall和Mareen首次从慢性活动性胃炎患者的胃粘膜中分离出为幽门螺杆菌(Hp)。本文概括了Hp与上胃肠道疾病的关系，并评估其感染的治疗。现已确认Hp与4种上胃肠道疾病密切相关：(1)慢性胃炎；(2)消化性溃疡病；(3)胃癌；(4)胃粘膜相关淋巴样组织(MALT)淋巴瘤。Hp是慢性胃炎的主要病因，与消化性溃疡病的发生密切相关，Hp感染增加了胃腺癌发生的危险性，而且也涉及到胃MALT淋巴瘤发生的致病机理。Hp感染的治疗是以PPI、铋制剂以及RBC为基础的三联疗法，当三联疗法失败时则推荐四联疗法。四联疗法是传统的三联疗法(铋剂为基础的三联疗法)十PPI组成。     

Current concepts in the management of Helicobacter pylori infection: the Maastricht III Consensus Report

BACKGROUND: Guidelines on the management of Helicobacter pylori, which cover indications for management and treatment strategies, were produced in 2000. AIMS: To update the guidelines at the European Helicobacter Study Group (EHSG) Third Maastricht Consensus Conference, with emphasis on the potential of H pylori eradication for the prevention of gastric cancer. RESULTS: Eradication of H pylori infection is recommended in (a) patients with gastroduodenal diseases such as peptic ulcer disease and low grade gastric, mucosa associated lymphoid tissue (MALT) lymphoma; (b) patients with atrophic gastritis; (c) first degree relatives of patients with gastric cancer; (d) patients with unexplained iron deficiency anaemia; and (e) patients with chronic idiopathic thrombocytopenic purpura. Recurrent abdominal pain in children is not an indication for a "test and treat" strategy if other causes are excluded. Eradication of H pylori infection (a) does not cause gastro-oesophageal reflux disease (GORD) or exacerbate GORD, and (b) may prevent peptic ulcer in patients who are na?ve users of non-steroidal anti-inflammatory drugs (NSAIDs). H pylori eradication is less effective than proton pump inhibitor (PPI) treatment in preventing ulcer recurrence in long term NSAID users. In primary care a test and treat strategy using a non-invasive test is recommended in adult patients with persistent dyspepsia under the age of 45. The urea breath test, stool antigen tests, and serological kits with a high accuracy are non-invasive tests which should be used for the diagnosis of H pylori infection. Triple therapy using a PPI with clarithromycin and amoxicillin or metronidazole given twice daily remains the recommended first choice treatment. Bismuth-containing quadruple therapy, if available, is also a first choice treatment option. Rescue treatment should be based on antimicrobial susceptibility. CONCLUSION: The global burden of gastric cancer is considerable but varies geographically. Eradication of H pylori infection has the potential to reduce the risk of gastric cancer development.     

IL-18 与幽门螺杆菌感染的关系及其致病作用研究进展

白细胞介素-18(IL-18)是一种重要的细胞免疫调节因子,幽门螺杆菌(H.pylori)能促进胃上皮细胞和黏膜固有层单核细胞分泌IL-18,参与包括慢性胃炎、消化性溃疡、胃癌和胃黏膜相关淋巴组织(MALT)淋巴瘤等多种胃十二指肠疾病的发生。本文就IL-18与H.pylori感染的关系及其致病作用研究进展作一综述。     

宿主免疫基因多态性与幽门螺杆菌感染相关疾病的关系

幽门螺杆菌(Helicobacter pylori,H.pylori)感染与消化性溃疡、萎缩性胃炎、胃MALT(Mucosa-associated lymphoid tissue)淋巴瘤及胃癌等疾病的发生密切相关。H.pylori感染引起的不同临床结局主要与H.pylori致病因子、宿主因素和环境因素三方面有关。目前宿主基因易感性的差异在H.pylori感染致病的作用已成为研究热点,本文就宿主免疫基因的多态性与幽门螺杆菌感染所致疾病关系的研究进行总结,从宿主TOLL样受体、NOD受体、CD14及HLA等免疫因子基因多态性进行综述。     

幽门螺杆菌致病机制及益生菌防治作用的研究进展

幽门螺杆菌(H pylori)己被确认与慢性胃炎、消化性溃疡、胃黏膜相关淋巴样组织淋巴瘤和胃癌密切相关,目前多种抗生素联合治疗仍是抗H pylori感染的主要方法,但是由于细菌抗药性的出现、以及长期不合理应用抗生素可引起不良反应,因此近年提出了抗H pylori感染一些新方法,其中益生菌在提高H pylori根除率及减少药物不良反应方面尤显优势,而且还具有维持胃肠道微生态的稳定、减轻黏膜炎症反应等多种作用,本文就H pylori的致病机制及益生菌治疗H pylori感染的研究进展作一综述.     

The time to eradicate gastric cancer is now

Worldwide gastric cancer remains one of the most common cancers, killing upwards of one million people each year. While the molecular pathogenesis remains unclear, infection with the bacterium Helicobacter pylori is considered a "necessary but not sufficient" cause, not surprisingly as gastric cancer has long been known to be associated with atrophic gastritis. Eradication of H pylori is expected to virtually eliminate gastric cancer and H pylori associated peptic ulcer within approximately 40 years and thus reduce overall mortality. In the USA, the incidence of gastric cancer in the general population is low, reflecting the change in the pattern of gastritis from atrophic to non-atrophic and in the low and decreasing prevalence of H pylori infection in the middle and upper classes. However, the plan for eradication of this important pathogen must be considered within the context of the prevalence and outcome within specific populations.     

Clinical aspects of Helicobacter pylori infection

The Helicobacter pylori (Hp) infection is common. However, only 10-20% of infected individuals require antibacterial treatment. The main indications to such treatment are peptic ulcer disease, atrophic gastritis, dyspeptic symptoms, previous surgical procedure for gastric cancer, family history of gastric cancer and low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The treatment may also be undertaken at the patient's request. To detect the infection the urease test (when the patient has indications for gastroscopy), the urea breath test or serologic test are most commonly used. A standard treatment of Hp infection consists of a 7-day administration of one of the proton pump inhibitors and 2 out of 3 antibiotics such as amoxicillin, clarithromycin and metronidazole. After failure of the first-line treatment, the recommended second choice treatment is a quadruple treatment regimen consisting of bismuth salts, tetracycline, metronidazole and proton pump inhibitor. European guidelines (Maastricht III) allow the use of the quadruple treatment regimen already as the first choice treatment and therapy prolongation up to 14 days. Ineffectiveness of the second-line treatment is an indication for antimicrobial susceptibility testing. New antibiotics used for Hp eradication are levofloxacin and rifabutin. Eradication treatment should be obligatorily assessed with the use of the urease or breath test only in patients with peptic ulcer bleeding. The current guidelines do not envisage an active search for Hp infection in an asymptomatic population and treating people infected with this bacterium, for gastric cancer prevention.     

Distinct gene expression profiles in gastric epithelial cells induced by different clinical isolates of Helicobacter pylori--implication of bacteria and host interaction in gastric carcinogenesis

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infection is a major risk factor of peptic ulcer, gastric cancer, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The interplay between H. pylori and host is an important issue for elucidation of pathogenesis of H. pylori-related diseases. We aimed to examine simultaneously dynamic changes of multiple molecular pathways of infection affected by different H. pylori strains by cDNA microarrays. METHODOLOGY: To elucidate the cross-talk between H. pylori and gastric epithelial cells, we isolated three different H. pylori strains from patients with gastric cancer (GC), duodenal ulcer (DU), and gastric MALT lymphoma (MA). The bacteria were co-cultured with gastric epithelial cells (AGS) and total RNAs were extracted from AGS cells and used for detection of genes represented in the microarray. RESULTS: Of the 12,814 clones on the microarray, there were 522 genes expressed differently in the three groups. Of the 522 genes, there were 4 genes, 4 genes and 13 genes, either up- or down-regulated more than twofold change, in AGS cells induced specifically by GC, MA, and DU strain, respectively. The GC and DU strains induced more genes involving in carcinogenesis, such as pim-1, jun B, and VEGF. CONCLUSIONS: Our data by cDNA microarray suggest bacterial factors may determine the outcomes of H. pylori infection. The expression profiles of cDNA microarray provide clues for diagnosis, treatment, and prevention of H. pylori-related gastroduodenal diseases.     

Gastritis caused by Helicobacter heilmannii (Gastrospirillum hominis). Report of 3 cases

Helicobacter heilmannii infection is rare. Its clinical picture is rather different from that caused by Helicobacter pylori: alterations in the gastric mucosa are milder and mainly located in the gastric antrum, and the frequency of erosions and ulcers is lower. It has been described in association with conditions similar to those related to H. pylori: peptic ulcer, chronic gastritis, gastric adenocarcinoma, intestinal metaplasia and MALT (mucose associated lymphoid tissue) lymphoma, although the incidence is lower. We describe three cases of gastritis caused by H. heilmannii, which we consider to be of interest because of the absence of cases published in Spain. One of the cases is especially unusual because of its association with a duodenal ulcer. We also describe the main features of H.r heilmannii. Its clinical treatment is similar to that used in H. pylori, with demonstrated morphological improvement of the lesions after eradication of the infectious agent.