[Pathology of Helicobacter infection].

The colonization of gastric mucosa by Helicobacter pylori (H.p.) is a special form of chronic bacterial infection characterized by long term persistence of microbes because cause of an inefficiency of local immune responses. The resulting chronic gastritis causes decisive transformations of gastric mucosa. They comprise the acquisition of an active mucosa-associated lymphoid tissue as well as the development of glandular atrophy and intestinal metaplasia in the stomach. Both transformations change normal gastric functions, and create abnormal microenvironments with an increased risk for gastric cancer and lymphoma. Own recent investigations indicate, that the distribution and severity of chronic gastritis might be decisively influenced by a rise of antigastric autoimmune reactivity during the H.p. infection. The histologic examination of gastric biopsy samples is essential for an exact diagnosis of the complex pathogenic processes in chronic gastritis. In the future special emphasis of histologic analyses has to be put on the subtypes of gastritis, which are prone for complications and on the evaluation of gastritis remission after H.p. eradication.