Abstract
Objective:To investigate the effect of proton pump inhibitor（PPI） treatment on salivary pepsin concentration in laryngopharyngeal reflux（LPR）. Methods:152 patients with suspected LPR complaining non-specific symptoms such as foreign body sensation, dry throat, phlegm and other non-specific symptoms were enrolled， in the Second Affiliated Hospital of Xi'an Jiaotong University from August 2019 to December 2020. According to the scores of reflux symptom index（RSI） and reflux finding score（RFS）, all the patients were divided into LPR （+） group and LPR （-） group, RSI （+） group and RSI （-） group, RFS （+） group and RFS （-） group . Patients in the LPR （+） group were reassessed after 1 month of PPI treatment. Saliva samples were collected from all the patients at initial diagnosis and follow-up diagnosis after treatment. The salivary pepsin concentration was determined by enzyme linked immunosorbent assay （ELISA）. The differences of RSI, RFS scores and salivary pepsin concentrations before and after treatment were compared. Results:The median concentration of salivary pepsin in LPR （+） group was significantly higher than that in LPR （-） group, and （73.01 ng/mL vs 25.66 ng/mL, P<0.01）, the median concentration of salivary pepsin in RFS （+） group were significantly higher than that in RFS （-） group（78.00 ng/mL vs 35.79 ng/mL, P<0.01） Furthermore, the median scores of RSI （11.00 vs 7.00, P<0.05） and RFS （9.00 vs 7.00, P<0.01） of LPR （+） patients notably decreased after PPI treatment for 1 month, and the salivary pepsin median concentration was memorably lower than that before treatment（53.60 ng/mL vs 46.49 ng/mL, P<0.05）. Meanwhile, the scores of symptoms such as pharyngeal paraesthesia, heartburn, chest pain, stomachache, and the scores of signs such as false vocal fold, erythema or congestion, vocal fold edema, posterior commissure hypertrophy and thick endolaryngeal mucus were conspicuously lower after treatment than those before treatment（P<0.05）. Conclusion:After 1 month of PPI treatment, the scores of partial symptoms and signs, and the salivary pepsin concentrations of LPR patients decreased significantly, suggesting that pepsin plays an important role in the pathogenesis of LPR, and pepsin may be closely related to the symptoms and signs such as pharyngeal paraesthesia and vocal fold edema.