Immunoserologic Pepsin Detection in The Saliva as a Non-Invasive Rapid Diagnostic Test for Laryngopharyngeal Reflux

Background: The most common tool for the diagnosis of laryngopharyngeal reflux (LPR) is still 24-hours esophageal pH monitoring; there is lack of non-invasive, less expensive and accurate diagnostic tools for this frequent disease. Aims: To evaluate the accuracy of immunoserologic pepsin detection in the saliva for the diagnosis of LPR. Study Design: Cross-sectional study. Methods: A two channeled 24-hour esophageal pH monitoring catheter was placed in patients with a suspicion of LPR. During the 24-hour period, each patient gave one sample of sputum for the immunoserologic pepsin detection test. Pathologic gastroesophageal reflux (GER) findings, LPR findings, pH score in the proximal and distal probes when the sputum sample was given were recorded. The sensitivity, specificity, positive and negative predictive values of the pepsin detection test were analyzed and compared to pH monitoring scores. Results: The study group consisted of 20 patients who met the criteria. A positive pepsin detection test was elicited from 6 patients. The sensitivity and specificity of the pepsin detection test was 33% and 100%, respectively. A positive predictive value of 100% was recorded. When the pH results of the pepsin positive patients (PPP) and the rest of the study group in the proximal probe at the sample time were compared, the PPP had an apparent acidic pH value compared to the pepsin negative patients (pH: 3.26 for the PPP, pH: 6.81 for the pepsin negative patients). Conclusion: Pepsin detection in the saliva is a recent method and becoming increasingly popular. Because of the benefits and ease of application, a positive salivary pepsin test in a patient suspected of having LPR can be a cost effective, accurate and alternative diagnostic method. Increasing the daily number of sputum samples may increase the sensitivity of the test.