1 | INTRODUCTION
Helicobacter pylori (H. pylori) is a gram-negative bacterium affecting up to 50% of the population worldwide and is the most common cause of chronic gastritis, peptic ulcer, and gastric cancer(1-3). Eradication of chronic H. pylori infection significantly reduces gastric cancer risk(4-6). A systematic review including ten randomized controlled trials provided evidence that H. pylori eradication therapy reduces gastric cancer incidence in healthy individuals and patients with gastric neoplasia(7). The strong association between H. pylori and gastric cancer risk highlights the importance of adequate detection and eradication of H. pylori in clinical practice.
Conventional examinations for the diagnosis of H. pylori infection include noninvasive and gastroscopic biopsy-based tests. These examinations, however, cannot evaluate endoscopic findings associated with H. pylori infection (8-13). Recently, many investigators have attempted to characterize endoscopic features indicative of H. pylori infection. Several endoscopic features in the Kyoto classification of gastritis, such as the regular arrangement of collecting venules (RAC), diffuse redness, or atrophy, have been proposed to evaluate the status of H. pylori infection and the potential risk of developing gastric cancer(14).
RAC is an endoscopic feature defined as numerous red dots regularly distributed over the entire gastric body(15, 16). The presence of RAC at the level of the distal part of the lesser gastric curvature has been regarded as a characteristic endoscopic feature of the H. pylori-negative normal stomach. However, data on the diagnostic accuracy of RAC as an endoscopic marker for the diagnosis of H. pylori infection are conflicting, with reported sensitivity ranging from 86% to 100% and specificity ranging from 7% to 98%(17-31). Variations in the sensitivity and specificity of RAC for H. pylori infection in these studies highlight the need for a comprehensive evaluation of the diagnostic performance of RAC before broader application. Therefore, this study was conducted to determine the diagnostic accuracy and clinical utility of RAC for the diagnosis of H. pylori infection.