Classification of gastritis--yesterday, today and tomorrow.

The major landmark in the recent history of gastritis was the discovery of Helicobacter pylori as the cause for approximately 90% of cases of chronic gastritis. This was followed by an attempt to rationalise classification from the many conflicting nomenclatures in existence to one, the Sydney System, that might gain more universal acceptance and allow studies from around the world to be compared. In the decade since its inception, including an appropriate update, the system has partially achieved this aim. It is based on documenting the topography of the gastritis, this reflecting the range of possible clinical outcomes and point of progress along the gastritis-metaplasia-dysplasia-carcinoma cascade. The rapidly expanding molecular knowledge about host mucosal immunology, determinants of bacterial virulence and dietary constituents makes it likely "tomorrow's" classification will be an algorithm to include several such factors. From this an exact "peptic" patient profile could be constructed. However one must also speculate that interest in gastritis and its classification could whither just as quickly as it blossomed with the advent of a successful vaccine.