Funding for this study was provided by the Center for Voice and Swallowing Disorders
Sensitive Pepsin Immunoassay for Detection of Laryngopharyngeal Reflux†
Article first published online: 3 JAN 2009
Copyright © 2005 The Triological Society
Volume 115, Issue 8, pages 1473–1478, August 2005
How to Cite
Knight, J., Lively, M. O., Johnston, N., Dettmar, P. W. and Koufman, J. A. (2005), Sensitive Pepsin Immunoassay for Detection of Laryngopharyngeal Reflux. The Laryngoscope, 115: 1473–1478. doi: 10.1097/01.mlg.0000172043.51871.d9
- Issue published online: 3 JAN 2009
- Article first published online: 3 JAN 2009
- Manuscript Accepted: 9 MAY 2005
- laryngopharyngeal reflux;
- gastroesophageal reflux;
- pH monitoring;
- reflux laryngitis;
Objectives/Hypothesis: To determine whether measurement of pepsin in throat sputum by immunoassay could be used as a sensitive and reliable method for detecting laryngopharyngeal reflux (LPR) compared with 24-hour double-probe (esophageal and pharyngeal) pH monitoring.
Study Design: Patients with clinical LPR undergoing pH monitoring provided throat sputum samples during the reflux-testing period for pepsin measurement using enzyme-linked immunoadsorbent assay.
Results: Pepsin assay results from 63 throat sputum samples obtained from 23 study subjects were compared with their pH monitoring data. Twenty-two percent (14/63) of the sputum samples correlated the presence of pepsin with LPR (pH ≤ 4 at the pharyngeal probe), of which the median concentration of pepsin was 0.18 μg/mL (range 0.003–22 μg/mL). Seventy-eight percent (49/63) of the samples unassociated with (pharyngeal) reflux contained no detectible pepsin. Mean pH values for pepsin-positive samples were significantly lower than negative samples at both esophageal probe (pH 2.2 vs. pH 5.0) (P < .01) and the pharyngeal probe (pH 4.4 vs. pH 5.8) (P < .01). When the pepsin assay results were compared with the pharyngeal pH data for detecting reflux (events pH ≤ 4), the pepsin immunoassay was 100% sensitive and 89% specific for LPR.
Conclusions: Detection of pepsin in throat sputum by immunoassay appears to provide a sensitive, noninvasive method to detect LPR.