The Diagnostic Usefullness of the Salivary Pepsin Test in Symptomatic Laryngopharyngeal Reflux

Abstract

Laryngopharyngeal Reflux (LPR) is a disease characterized by the presence of symptoms, signs and tissue alterations in the aero-digestive upper tract as a consequence of the gastric contents retrograde movement. In most cases diagnosis is clinical and it is established by the presence of symptoms and endoscopic laryngeal signs. The aim of the study was to determine the sensitivity, specificity, positive and negative Likelihood Ratio (LR) of the salivary pepsin assay (PEP-test, RD Biomed, Hull, UK) as diagnostic tool of LPR. Diagnostic Accuracy Study. 221 subjects aged between 26 and 68 years were recruited. All subjects completed the Reflux Symptom Index scale. PEP-test was carried out on fasting subjects, and a second test was performed one hour after the main meal, only on those subjects with a fasting negative result. Fasting PEP-test showed a 98% specificity, 40% sensitivity, positive LR of 16.4 and negative LR of 0.61. The use of both PEP-test showed a 95% specificity, 48% sensitivity, positive LR of 9.61 and negative LR of 0.55. The PEP-test is a simple, inexpensive, non-invasive and easily reproducible test that should be considered as an alternative diagnosis tool for LPR diagnosis. When there is a clinical suspicion of LPR disease, a positive result on the test could be considered diagnostic, but on subjects with negative results it should be complemented with more complex tests such as the 24-hour dual-channel pH-metry.