The updated Sydney system: Classification and grading of gastritis as the basis of diagnosis and treatment

In recent years, the importance of the histological diagnosis of gastritis on the basis of routinely obtained antral and corpus biopsies has increased enormously, which is owed not least of all to the discovery of Helicobacte r pylori. The introduction of the Sydney system made it possible, for the f irst time, to grade histological parameters, identify topographical distrib ution and, finally, make a statement about the etiopathogenesis of the gast ritis. Of pathogenetic importance is, in the first instance, the differenti ation between gastritis with and gastritis without H pylori infection. The group of H pylori-associated gastritis can be further subdivided into forms of gastritis whose morphological distribution patterns usually identify th em as sequelae of H pylori infection, while the group of gastritis unassoci ated with H pylori can be differentiated into autoimmune, chemically induce d reactive gastritis, ex-H pylori gastritis, Helicobacter heilmannii gastri tis, Crohn's gastritis and a number of special forms of gastritis.