Classification of chronic gastritis in the post-sydney era: a discourse

Abstract

Chronic gastritis is defined histologically as an increase in the number of lymphocytes and plasma cells in the gastric mucosa. The definition and classification of this entity had been a subject of intensive research, long before the discovery of Helicobacter pylori by Warren and Marshal. The Sydney system of classification was introduced at a time when there was a dire need for greater consistency in nomenclature so as to be able to compare clinical studies emanating from pathology reports of gastric biopsies. The system achieved this objective to a large extent but histology reports continued to lack information on the prediction of risk of gastric cancer development. There was a need for clear guidelines on clinico-endoscopic surveillance for gastric cancer.

In an attempt to address this shortcoming, an international group of gastroenterologists and pathologists called Operative Link for Gastritis Assessment (OLGA) proposed a system which grades chronic gastritis according to gastric cancer risk, comparable to the histology reporting format that proved very successful in chronic hepatitis.

Helicobacter pylori is the etiologic agent of chronic gastritis in the vast majority of cases as its worldwide epidemiology overlaps that of chronic gastritis. It is also the most important risk factor for the development of non-cardia gastric cancer, being responsible for almost 90% of such cases worldwide. In gastric cancer development, Helicobacter pylori-induced chronic gastritis is the first step in the so-called “Correa” cascade.

The Kyoto consensus on Helicobacter pylori gastritis is the first global consensus for gastritis and touched on various aspects, including classification, designation of Helicobacter pylori gastritis as an infectious disease, recommendation that all infected subjects be treated regardless of whether they have clinical manifestations or not, separation of Helicobacter pylori gastritis from functional dyspepsia, and the interaction of Helicobacter pylori with other microbiota in the digestive tract.

The Maastricht Consensus on Helicobacter pylori management which was developed by the European Helicobacter Pylori Study Group (EHPSG) has moved from the 1st edition published in 1997 to the 5th which was released in 2015 (Maastricht V). The aspect of this latest version that touched on chronic gastritis is consistent with the provisions of the Kyoto consensus.

In a similar vein, the International Classification of Diseases (ICD) is currently being revised from ICD-10 to ICD-11. The formative stage of ICD-11 (ICD-11 β component) is still being compiled and is expected to capture the issue of etiologic classification of chronic gastritis which was conspicuously absent in ICD-10.

Image-enhanced endoscopy is a fast growing technique in the diagnosis of gastric premalignant lesions. It is expected that in the not too distant future, there would be classification systems for chronic gastritis that would be based on this new technology.