Pepsin and oropharyngeal pH monitoring to diagnose patients with laryngopharyngeal reflux

OBJECTIVES: The aim of this study was to compare the diagnostic accuracy of salivary pepsin with oropharyngeal pH monitoring using the Restech measurement system (Dx‐pH) for the diagnosis of laryngopharyngeal reflux (LPR). STUDY DESIGN: Prospective cohort study. METHODS: Seventy patients with primary symptoms related to LPR underwent gastroscopy, high‐resolution manometry, pH throughout 24‐hour monitoring (MII‐pH), and barium esophagography between October 2015 and May 2018. In addition, an ear, nose, and throat examination was performed, including assessment of Belafsky Reflux Finding Score (RFS). Clinical symptoms were evaluated with the Belafsky Reflux Symptom Index (RSI) and the Gastrointestinal Quality of Life Index (GIQLI). Simultaneous to MII‐pH, pepsin determination and Dx‐pH were performed. RESULTS: Of 70 patients, 41 (58.6%) subjects with a pathological DeMeester score showed higher mean values of pepsin (mean value: 216 ng/mL, 95% confidence interval [CI]: 172 to 260), compared to patients with a normal DeMeester score (mean value: 161 ng/mL, 95% CI: 115 to 207). Salivary pepsin showed a specificity of 86.2% and sensitivity of 41.5% for diagnosing LPR using the optimal cutoff value of 216 ng/mL. Furthermore, a significant correlation between the values of salivary pepsin and the RSI score was seen in patients with pathological results in MII‐pH (r = 0.344; P = 0.046). However, elevated Dx‐pH measurements showed no significant correlation with either MII‐pH, RSI score, RFS score, or GIQLI score, or with the results of pepsin measurement. CONCLUSION: Pepsin measurement in saliva could be an alternative tool to assist office‐based diagnosis of LPR, whereas Dx‐pH does not seem to be an adequate test. LEVEL OF EVIDENCE: 2B Laryngoscope, 130:1780–1786, 2020