Clinical value of the endoscopic scratch sign in diagnosing Helicobacter pylori infection status

Abstract

Accurate assessment of Helicobacter pylori ( H. pylori ) infection status is essential for clinical decision-making. This study aimed to evaluate the clinical utility of the endoscopic scratch sign which refers to linear reddish streaks observed along the greater curvature of the gastric body in identifying H. pylori -negative status. In this prospective observational study, consecutive patients who underwent upper gastrointestinal endoscopy between January and August 2025 were enrolled. Clinical, endoscopic, and histopathological data were collected. The diagnostic performance of the scratch sign for predicting H. pylori -negative status was assessed by calculating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Multivariate analysis was performed to identify independent factors associated with the presence of the scratch sign. A total of 587 patients were included, comprising 363 H. pylori -uninfected individuals, 143 with past infection, and 81 with active infection. The prevalence of the scratch sign was significantly higher in H. pylori -uninfected (86.8%) and previously infected patients (88.1%) than in those with active infection (22.2%). Multivariate analysis demonstrated that female sex, H. pylori infection status, atrophic changes of the gastric mucosa, and bile reflux were independently associated with the presence of the scratch sign. Female patients and those without active H. pylori infection were more likely to exhibit a positive scratch sign, whereas chronic atrophic gastritis and bile reflux were negatively associated with its presence. For predicting H. pylori -negative status, the scratch sign demonstrated an accuracy of 85.9%, sensitivity of 87.2%, specificity of 77.8%, PPV of 96.1%, and NPV of 49.2%. Moreover, patients with moderate-to-severe chronic inflammation or active inflammation showed a significantly lower prevalence of the scratch sign (both P < 0.001). Endoscopists with different experiences have a high degree of consistency in the diagnosis of scratch signs (kappa values:0.61–0.80). The endoscopic scratch sign is a reliable and practical indicator for identifying H. pylori -negative status and appears to be independent of exogenous pharmacological influences.