Association between regular arrangement of collecting venules and Helicobacter pylori status in routine endoscopy

Background The sensitivity of regular arrangement of collecting venules (RAC)-positive pattern for predicting Helicobacter pylori (H. pylori)-negative status greatly altered from 93.8 to 48.0% in recent two decades of various studies, while the reason behind it remained obscure. The aim of this study was to investigate the value of RAC as an endoscopic feature for judging H. pylori status in routine endoscopy and reviewed the underlying mechanism. Methods A prospective study with high-definition non-magnifying endoscopy was performed. RAC-positive and RAC-negative patients were classified according to the collecting venules morphology of the lesser curvature in gastric corpus. Gastric biopsy specimens were obtained from the lesser and greater curvature of corpus with normal RAC-positive or abnormal RAC-negative mucosal patterns. Helicobacter pylori status was established by hematoxylin and eosin staining and immunohistochemistry. Results 41 RAC-positive and 124 RAC-negative patients were enrolled from June 2020 to September 2020. The prevalence of H. pylori infection in patients with RAC-positive pattern and RAC-negative pattern was 7.3% (3/41) and 71.0% (88/124), respectively. Among all 124 RAC-negative patients, 36 (29.0%) patients were H. pylori-negative status. Ten patients (32.3%) demonstrated RAC-positive pattern in 31 H. pylori-eradicated cases. The sensitivity, specificity, positive predictive value, and negative predictive value of RAC-positive pattern for predicting H. pylori-negative status were 51.4% (95% CI, 0.395-0.630), 96.7% (95% CI, 0.900-0.991), 92.7% (95% CI, 0.790-0.981), and 71.0% (95% CI, 0.620-0.786), respectively. Conclusions RAC presence can accurately rule out H. pylori infection of gastric corpus, and H. pylori-positive status cannot be predicted only by RAC absence in routine endoscopy. Trial registration The present study is a non-interventional trial.