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Updated: Jan 21, 2026

Murine Nasal Lavage Fluid Collection without Blood Contamination
Published on: July 11, 2025
Correlation of salivary and nasal lavage pepsin with MII-pH testing
Miles J Klimara1, Nikki Johnston1, Tina L Samuels2
1Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, U.S.A.
Objectives:
Laryngopharyngeal reflux (LPR) is a common upper airway disease. Salivary pepsin is a proposed marker for LPR; however, the optimal time for collection of specimens for pepsin detection and pepsin's presence in the oral and nasal secretions relative to concurrent multichannel intraluminal impedance-pH (MII-pH) monitoring are unknown.
Study Design:
Prospective case-control study with an experimental design.
Methods:
Patients undergoing MII-pH testing for evaluation of LPR and asymptomatic control subjects were selected. Nasal lavage and saliva samples were collected in the clinic prior to MII-pH probe placement. Additional saliva samples were obtained an hour after each meal and upon waking the following morning. Nasal lavage and salivary pepsin were measured by ELISA.
Results:
Twenty-six patients undergoing MII-pH testing and 13 reflux-free control patients were enrolled. Salivary pepsin was detected in 11 of 26 patients with suspected LPR and 0 of 13 controls. Pepsin was most frequently detected in the specimen provided upon waking at an average concentration of 186.9 ng/mL. A significant correlation was observed between salivary pepsin in waking samples to MII-pH measurements, including reflux bolus duration, and proximal and distal recumbent reflux episodes (P < 0.05). A significant correlation was also observed between salivary pepsin upon waking or sinus lavage and reflux symptom index (P < 0.05).
Conclusion:
Pepsin in salivary and nasal lavage samples demonstrated an association with MII-pH-documented LPR. Pepsin detection was most frequent in morning samples, supporting use of morning salivary pepsin levels as a potential noninvasive technique for LPR diagnosis.
Level Of Evidence:
2 Laryngoscope, 130:961-966, 2020.
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