For quite a long time, I thought the expression was “Pass Mustard”.

A recent study (F Dy et al. J Pediatr 2016; 177: 53-8) shows that testing salivary pepsin is probably a waste of time in assessing for extraesophageal reflux disease. The authors prospectively recruited 50 children who underwent multiple studies including 24-hour pH-MII testing. The idea of pepsin as a biomarker has some plausibility since it is produced in the stomach and its presence in the oropharynx (or airway) would be unexpected.  Since salivary pepsin does not require invasive diagnostic testing, it would be useful if it had adequate sensitivity and specificity.

Key findings:

• 21 of 50 (42%) were salivary pepsin-positive with a median concentration of 10 ng/mL.  Pepsin was detected in 6 of 21 with abnormal impedance testing and 8 of 21 with abnormal pH results (per Table 1 –the discussion used a denominator of 11 for each of these results)

• There was no significant correlation between salivary pepsin-positivity compared with salivary pepsin-negative for reflux episodes, acid reflux, nonacid reflux or any other reflux variable.

• The authors also reiterate in the discussion that clinical trials, evaluating reflux and chronic cough, “have failed to find a consistent relationship between measure dreflux and clinical response.”
• The authors note that bronchoscopy pepsin correlation with esophageal reflux monitoring was similarly low in sensitivity
• The authors note that “one-third of healthy asymptomatic adults have pepsin detected in their saliva.”  In this study, 38% (15 of 39) of children had pepsin detected despite normal impedance results.

My take:  While this study mainly shows that pepsin detected in the saliva has no practical use in correlation with reflux, the bigger picture is the uncertain relationship of reflux as a causal association with chronic cough.

Any of the reflux-esophageal gurus care to comment?

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Carriage Road in Acadia National Park