Role of Helicobacter pylori infection in extragastroduodenal disorders: introductory remarks.

Numerous studies initiated by Warren and Marshall in 1982 confirmed the crucial role of H. pylori infection in the pathogenesis of gastritis, peptic ulcer and possibly also gastric cancer leading to reappraisal of fundamental concept of gastric pathophysiology. These topics were covered, in part, by our previous H. pylori-related symposium I (1995), II (1997) and III (1999) organized in Cracow. H. pylori is one of the most frequent causes of gastroduodenal infection worldwide, resulting in the release of various bacterial and host dependent cytotoxic substances including ammonia, platelet activating factor (PAF), cytotoxins and lipopolysaccharides (LPS) as well as cytokines such as interleukins (IL)-1-12, tumor necrosis factor alpha (TNF(alpha), interferon gamma (INFgamma) and reactive oxygen species (ROS). Recently, several extradigestive pathologies have been linked to H. pylori infection including cardiovascular, cutaneous, autoimmune, esophageal and other diseases such as sideropenic anemia, growth retardation, extragastric MALT-lymphoma etc. The potential role of H. pylori infection in the pathogenesis of these extradigestive disorders has been based on facts that 1) local gastric inflammation may exert systemic effects, 2) chronic infection of gastric mucosa induces immune responses that are able to cause the lesions remote to primary site of infection and 3) H. pylori eradication improves the extradigestive disorders. The aim of present III International Symposium is to provide critical reviews based on personal experience and the available literature about extragastric manifestations of H. pylori infection. The ultimate goal of this symposium is to foster interdisciplinary research and exchange of opinion about the possible involvement of H. pylori in extradigestive pathologies.