Validation of the Nasopharyngeal Reflux Endoscopic Score (NRES) in the Diagnosis of Chronic Rhinosinusitis with Laryngopharyngeal Reflux Disease

Background: Chronic rhinosinusitis with or without nasal polyps (CRSwNP/CRSsNP) is a multifactorial inflammatory disease that is increasingly associated with laryn-gopharyngeal reflux disease (LPRD). While symptom-based questionnaires such as the Reflux Symptom Index (RSI) and Reflux Symptom Score (RSS) are commonly used, there is a lack of objective endoscopic tools to assess nasopharyngeal and nasal mani-festations of reflux. The Nasopharyngeal Reflux Endoscopic Score (NRES) was devel-oped to fill this gap. Objective: To evaluate the diagnostic utility of the NRES in patients with CRS and suspected LPRD and to compare its performance with existing clinical and endoscopic reflux assessment tools. Methods: A prospective longitudinal study was conducted with 216 adult participants divided into three groups: CRS with sus-pected LPRD (n = 116), CRS without LPRD (n = 69) and healthy controls (n = 31). The diagnosis of LPRD was suspected through gastrointestinal endoscopy, 24-hour pH monitoring, RSI and RSS. The diagnosis of CRS was made according to the EPOS 2020 criteria. All participants underwent nasopharyngeal and laryngeal endoscopy and were assessed at baseline, 6 months and 12 months using NRES, Lund-Kennedy (L-K), Reflux Finding Score (RFS), RSI and RSS. Receiver operating characteristic (ROC) analysis assessed diagnostic performance; Wilcoxon tests assessed score dynamics; correlation and regression analyses explored associations between scales and predic-tive factors. Results: At baseline, NRES scores were significantly higher in the CRS with LPRD group (mean: 11.59) compared to CRS without LPRD (mean: 3.10) and healthy controls (mean: 2.16) (p < 0.001). ROC analysis showed excellent diagnostic accuracy (AUC = 0.998) with 99% sensitivity and 96% specificity at a cut-off of 8.5. NRES showed strong correlations with RSI, RSS and RFS (r > 0.76, p < 0.001). Longitudinal assessment showed significant score reductions on all scales after treatment with proton pump inhibitors (PPIs) and lifestyle modifications, with sustained improvement at 12 months. Regression analysis showed no significant effect of age, gender or GERD severity (LA classification) on NRES scores. Conclusions: The NRES is a highly sensitive and specific endoscopic tool for identifying nasopharyngeal changes associated with LPRD in CRS patients. It shows strong correlations with both symptom-based and laryngoscopic re-flux assessment and responds to anti-reflux therapy over time. NRES may serve as a valuable objective adjunct in the comprehensive evaluation and longitudinal moni-toring of LPRD -associated CRS.