Diagnostic Utility of Salivary Pepsin as Compared With 24-Hour Dual pH/Impedance Probe in Laryngopharyngeal Reflux

• Published in: Otolaryngology-head and neck surgery Vol. 164; no. 2; p. 375
• Main Authors: Zhang, Michael, Chia, Clemente, Stanley, Claire, Phyland, Debra J, Paddle, Paul M
• Format: Journal Article
• Language: English
• Published: England 01.02.2021
• Subjects: Biomarkers - analysis; Circadian Rhythm - physiology; Electric Impedance; Esophageal pH Monitoring; Female; Humans; Hydrogen-Ion Concentration; Laryngopharyngeal Reflux - diagnosis; Laryngopharyngeal Reflux - metabolism; Male; Middle Aged; Pepsin A - analysis; Prospective Studies; Saliva - chemistry; extraesophageal reflux; salivary pepsin; 24 hour dual pH impedance probe; laryngopharyngeal reflux
• ISSN: 1097-6817
• DOI: 10.1177/0194599820951183

Laryngopharyngeal reflux (LPR) is defined as the retropulsion of gastric contents into the larynx, oropharynx, and/or nasopharynx. The 24-hour combined hypopharyngeal-esophageal multichannel intraluminal impedance with dual pH probe (24h-HEMII-pH) is currently the gold standard in LPR diagnosis; however, it is invasive, user dependent, and not always tolerated. This study assesses the diagnostic utility of salivary pepsin (Peptest) at different thresholds and during symptomatic periods as compared with the 24h-HEMII-pH probe in diagnosing LPR. Prospective cohort study. Private laryngology clinic in Melbourne, Australia. Thirty-five patients with a clinical history and endoscopic findings of LPR were recruited and simultaneously evaluated for LPR via 24h-HEMII-pH probe and salivary pepsin analysis at 5 key time points over the same 24-hour period. Salivary pepsin was 76.9% sensitive and had a positive predictive value (PPV) of 87.0% at a threshold of 16 ng/mL when compared with the 24h-HEMII-pH probe. If the pathologic pepsin threshold was raised to 75 ng/mL, salivary pepsin had a sensitivity of 57.7%, a specificity of 75.0%, and a PPV of 93.8%. Symptomatic testing conferred a superior specificity at 16 ng/mL (66.7%) and 75 ng/mL (100.0%) and a superior PPV at 16 ng/mL (92.3%) and 75 ng/mL (100.0%). Salivary pepsin detection is a simpler, more cost-effective, and less traumatic universal first-line alternative to 24h-HEMII-pH probe in diagnosing LPR. Superior specificities conferring greater diagnostic value may be achieved with higher thresholds and symptomatic testing. If clinical suspicion remains high following negative salivary pepsin analysis, a 24h-HEMII-pH study could provide further diagnostic information.