Assessment of Salivary Polymerase Chain Reaction as a Non-invasive Method for Detecting Helicobacter pylori Infection in Patients With Symptomatic Gastritis

Introduction: Helicobacter pylori infection is a major etiological factor in chronic gastritis and several gastroduodenal diseases. Although gastric biopsy remains the gold standard for diagnosis, it is invasive and not always suitable for screening or repeated monitoring. Saliva-based polymerase chain reaction (PCR) has emerged as a promising non-invasive diagnostic approach. The present study aimed to evaluate the diagnostic performance of salivary PCR for detecting H. pylori infection and to compare its findings with gastric biopsy results in patients with symptomatic gastritis. Materials and methods: This diagnostic accuracy study included 40 patients with symptomatic gastritis who were referred for upper gastrointestinal endoscopy. Unstimulated saliva samples were collected from all participants and analyzed using PCR targeting the 16S rRNA gene of H. pylori. Gastric biopsy with histopathological examination served as the reference standard. Diagnostic performance of salivary PCR was evaluated by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy. Statistical analysis included the Chi-square test and receiver operating characteristic (ROC) curve analysis. Results: Salivary PCR detected H. pylori deoxyribonucleic acid in 33 of 40 patients. When compared with biopsy findings, salivary PCR demonstrated a sensitivity of 88.8% and a specificity of 75.0%. The PPV was 96.96%, while the NPV was 42.85%. The overall diagnostic accuracy was 87.5%. Although PCR positivity was higher among biopsy-confirmed cases, the association between salivary PCR and biopsy findings was not statistically significant (χ²=1.85, p=0.17). ROC analysis demonstrated good diagnostic performance, with an area under the curve (AUC) of 0.82. Conclusion: Salivary PCR targeting the 16S rRNA gene demonstrates high sensitivity and good overall diagnostic accuracy for detecting H. pylori infection in patients with symptomatic gastritis. Although gastric biopsy remains the reference standard, salivary PCR represents a promising non-invasive adjunct that may be useful for screening and preliminary detection of H. pylori infection, particularly in settings where endoscopic evaluation is limited.