Kyoto classification of gastritis: Advances and future perspectives in endoscopic diagnosis of gastritis

Abstract

This editorial provides an update of the recent evidence on the endoscopy-based Kyoto classification of gastritis, clarifying the shortcomings of the Kyoto classification, and providing prospects for future research, with particular focus on the histological subtypes of gastric cancer (GC) and Helicobacter pylori ( H. pylori ) infection status. The total Kyoto score is designed to express GC risk on a score ranging from 0 to 8, based on the following five endoscopic findings: Atrophy, intestinal metaplasia (IM), enlarged folds (EF), nodularity, and diffuse redness (DR). The total Kyoto score reflects H. pylori status as follows: 0, ≥ 2, and ≥ 4 indicate a normal stomach, H. pylori -infected gastritis, and gastritis at risk for GC, respectively. Regular arrangement of collecting venules (RAC) predicts non-infection; EF, nodularity, and DR predict current infection; map-like redness (MLR) predicts past infection; and atrophy and IM predict current or past infection. Atrophy, IM, and EF all increase the incidence of H. pylori -infected GC. MLR is a specific risk factor for H. pylori -eradicated GC, while RAC results in less GC. Diffuse-type GC can be induced by active inflammation, which presents as EF, nodularity, and atrophy on endoscopy, as well as neutrophil and mononuclear cell infiltration on histology. In contrast, intestinal-type GC develops via atrophy and IM, and is consistent between endoscopy and histology. However, this GC risk-scoring design needs to be improved.

Endoscopic Kyoto and Kimura-Takemoto Classifications Are Comparable in Predicting High-Risk Gastric Precancerous Lesions

“…The EKC score includes 50% points (4 points) for evaluating the destruction and replacement of atrophic gastritis and 50% points (4 points) for evaluating active inflammation [28]. KTC was proven to develop gastric neoplasms among patients with severe or open-type endoscopic atrophy [15,29] and has also been advocated in recent European [30] and British guidelines [31].…”

“…KTC was proven to develop gastric neoplasms among patients with severe or open-type endoscopic atrophy [15, 29] and has also been advocated in recent European [30] and British guidelines [31]. Adding the scores of evaluating active inflammation and the scores of evaluating the destruction and replacement of atrophic gastritis into EKC may have inadvertently reduced EKC’s ability to evaluate GC risk when compared with KTC [28]. Our study showed that the EKC and KTC were comparable in predicting HGPLs (shown in Fig.…”

“…Therefore, a total EKC score of 4 or more is useful for determining GC risks. To summarize the role of EKC, Toyoshima et al [28] recognized that the EKC score reflects the presence of H. pylori as follows: a normal stomach, H. pylori -infected gastritis, and gastritis at risk for GC are denoted by 0, 2, and 4, respectively. In our study, the EKC score reflects H. pylori status as follows: a normal stomach, H. pylori -infected gastritis, and the risk of HGPLs are indicated by 0, 1, and 2, respectively.…”