Salivary pepsin detection is hailed a ‘simpler, more cost-effective and less traumatic universal first-line alternative’ to 24-hour pH monitoring in diagnosing laryngopharyngeal reflux disease (LPR).
For the first time, researchers have simultaneously evaluated the accuracy of pepsin detection against 24-hour pH monitoring in symptomatic patients.¹
LPR is associated with symptoms of throat clearing, persistent cough, hoarseness of voice, as well as globus pharyngeus (sensation of a lump in the throat). It is common and can account for up to 10 per cent of otolaryngology consultations.
The current ‘gold standard investigation’ for the diagnosis of LPR is a 24-hour combined hypopharyngeal-oesophageal multichannel intraluminal impedance with dual pH probe.
Known as 24h-HEMII-pH, for short, it’s basically a procedure that measures how often fluid refluxes (flows back) into your oesophagus and pharynx from your stomach and the pH of this fluid over a 24-hour period.
But it is invasive and costly and can be poorly tolerated by patients.
The study in Australia
Thirty patients with a clinical history and endoscopic findings of laryngopharyngeal reflux (LPR), took part in the study at a private laryngology clinic in Melbourne, Australia. They concurrently underwent 24h-HEMII-pH probe and saliva collection across the same 24-hour period. The saliva was collected at both routine time intervals, and when the patients experienced symptoms.
Of the 30 patients who completed the 24h-HEMII-pH probe, 26 had positive results for laryngopharyngeal reflux. Of these 30 patients, 23 also had ‘positive’ pepsin results.
Salivary samples collected during symptomatic periods conferred a very high positive predictive value for pepsin.
This suggests that a positive salivary pepsin test correlates highly with a positive 24h-HEMII-pH study result in a large proportion of patients where there is clinical suspicion for laryngopharyngeal reflux.
The study concluded: “Salivary pepsin detection is a simpler, more cost-effective, and less traumatic universal first-line alternative to a 24hHEMII-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 a negative salivary pepsin analysis, a 24h-HEMII-pH study could provide further diagnostic information.”
Professor Peter Dettmar says: “Compared to the current gold standard, Peptest provided a test with superior specificities and greater diagnostic value.”
Research author Paul Paddle, an Ear, Nose and Throat, Head and Neck Surgeon and Laryngologist Director at Melbourne ENT Group, says: “This study suggests that many patients may be able to achieve a diagnosis of LPR with a positive pepsin test alone, without having to proceed to 24h-HEMII-pH probe studies. In the era of COVID, being able to perform a test for LPR in the relative isolation of one’s own home may confer additional benefit.”
1. Zhang M, Chia C, Stanley C, Phyland DJ, Paddle PM. Diagnostic Utility of Salivary Pepsin as Compared With 24-Hour Dual pH/Impedance Probe in Laryngopharyngeal Reflux. Otolaryngology–Head and Neck Surgery. September 2020. doi:10.1177/0194599820951183