Immunohistochemical detection of pepsin in laryngeal mucosa for diagnosing laryngopharyngeal reflux


  • The authors have no funding, financial relationships, or conflicts of interest to disclose.



To investigate whether the pepsin immunohistochemical (IHC) staining of the laryngeal mucosa epithelia is an available test for diagnosing laryngopharyngeal reflux (LPR) in clinic.

Study Design:

Prospective case series.


Biopsy specimens from interarytenoid mucosa of LPR patients (seven acid LPR and eight nonacid LPR) and 21 sex- and age-matched normal controls were obtained for pepsin IHC staining. The diagnosis of LPR was based on 24-hour combined multichannel intraluminal esophageal impedance pH monitoring. The results of IHC staining were semiquantitatively analyzed and scored as negative (−), weakly positive (+), moderately positive (++), and strongly positive (+++).


Six of seven acid LPR (85.7%) and six of eight nonacid LPR (75%) mucosa samples were moderate to strongly positive for intracellular pepsin. By contrast, only three of 21 normal controls (14.3%) were moderately positive. The difference in intracellular pepsin between LPR and the normal laryngeal mucosa was statistically significant (P < .01). No significant difference in intracellular pepsin was observed between the acid and nonacid LPR mucosal samples (P = .453). Using weak positivity (+) as a cutpoint, the presence of intracellular pepsin in the laryngeal mucosa had a sensitivity of 100% and a specificity of 47.6% in detecting LPR (P < .05). However, using the moderate positivity (++) as the cutpoint, the pepsin had a slightly decreased sensitivity of 80% but a sharply increased specificity of 85.7% (P < .05) in the detection of LPR.


Pepsin IHC staining of the laryngeal mucosa appears to be a sensitive and specific test for diagnosing LPR in a clinical application.