title: Immunohistochemical detection of pepsin in laryngeal mucosa for diagnosing laryngopharyngeal reflux.
abstract: OBJECTIVE
  To investigate whether the pepsin immunohistochemical (IHC) staining of the laryngeal mucosa epithelia is an available test for diagnosing laryngopharyngeal reflux (LPR) in clinic.
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  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 (+++).
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Pepsin IHC staining of the laryngeal mucosa appears to be a sensitive and specific test for diagnosing LPR in a clinical application.
authors.affiliation: Department of Otolaryngology, First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Aiyun
authors.initials: A
authors.lastname: Jiang
authors.forename: Maojin
authors.initials: M
authors.lastname: Liang
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Su
authors.forename: Liping
authors.initials: L
authors.lastname: Chai
authors.forename: Wenbin
authors.initials: W
authors.lastname: Lei
authors.forename: Zhangfeng
authors.initials: Z
authors.lastname: Wang
authors.forename: Anjiang
authors.initials: A
authors.lastname: Wang
authors.forename: Weiping
authors.initials: W
authors.lastname: Wen
authors.forename: Minhu
authors.initials: M
authors.lastname: Chen
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D007820:Laryngeal Mucosa / Q000473:pathology*; D057045:Laryngopharyngeal Reflux / Q000175:diagnosis / Q000473:pathology*; D007828:Laryngoscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010434:Pepsin A / Q000032:analysis*; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D010434:Pepsin A