3b. Laryngoscope, 127:2413-2417, 2017.

Laryngopharyngeal reflux (LPR) is the back flow of gastric contents into the laryngopharynx. It is estimated that this disease affects 20-40 % of the United States population and is commonly encountered by otolaryngologists. Patients with LPR present with symptoms due to chronic laryngeal irritation such as hoarseness and cough. Pepsin, a gastric enzyme, has been shown to be a specific and sensitive biomarker for LPR. Measurement of pepsin in patients with LPR symptoms holds promise as a reliable diagnostic test. Studies have shown that pepsin induces cell damage, inflammation, and neoplastic changes independently of gastric acid in an endocytosis-dependent manner. Thus, pepsin has been proposed as a novel therapeutic target, especially for patients experiencing refractory symptoms on currently available anti-reflux medications. Further research is needed to elucidate the exact role that pepsin plays in inflammatory and neoplastic diseases of the laryngopharynx and to develop pharmacologic agents targeting pepsin.