[Histopathology of Helicobacter pylori infections].

Helicobacter pylori (H.p.) infection is associated in essentially all patients with a chronic active gastritis. According to the Houston-update of the Sydney classification grade and activity of the gastritis, the occurrence of intestinal metaplasia and atrophy as well as the density of H.p. colonization have to be semiquantitatively determined by the pathologists. Gastric acid production influences the severity of gastritis in antrum and body mucosa. In a subgroup of patients other forms of gastritis, such as lymphocytic gastritis, giant fold gastritis and atrophic gastritis may develop. After eradication plasma cells may persist in the lamina propria for years.