Abstract: Objective To determine whether detection of pepsin in the saliva could be useful for diagnosing laryngopharyngeal reflux(LPR). Methods Twenty-five patients having LPR with reflux symptoms index scale(RSI)>13 and a reflux symptoms index scale(RFS)>7 were selected. Pepsin levels were measured by protease-labeling prior to treatment. Patients were treated with esomeprazole along with 2.5% sodium bicarbonate atomization inhalation therapy. Two months after completion of treatment, the RSI, RFS, and pepsin in the saliva were measured again. Results Out of 25, 12 salivary samples were positive and 13 were negative before treatment. PPI test results were positive in 10 cases and negative in 15 cases after treatment. The results of saliva pepsin test and PPI test were both positive in 9 cases and negative in 12 cases. One case had a positive result in the PPI test, and 3 cases had positive results in the salivary pepsin test. The diagnostic criteria for this study included a positive result on PPI test, and a sensitivity and specificity of 90.00% and 80.00%, respectively, in the detection results of pepsin. All 25 patients were able to complete the entire investigation and treatment course. The symptoms improved in 19 cases, while they did not significantly improve in 6 cases. The scores of the RSI scale before and after treatment were 19.84±3.96 and 7.00±2.84 respectively, with the difference being statistically significant(P<0.001). Signs obviously improved in all 25 cases. The RFS scale score before and after treatment was 14.08±3.51 and 5.44±3.07 respectively, with the difference being statistically significant(P<0.001). Conclusion The detection of pepsin in the saliva can be used for the diagnosis of LPR.

Key words: Laryngopharyngeal reflux, Pepsin, Sodium