title: Hypopharyngeal pepsin and Sep70 as diagnostic markers of laryngopharyngeal reflux: preliminary study.
abstract: BACKGROUND
  The management of laryngopharyngeal reflux (LPR) has been challenging. Hypopharyngeal multichannel intraluminal impedance (HMII) has shown to increase the sensitivity in diagnosing LPR. The objective of this study is to investigate the potential use of pepsin and Sep70 as diagnostic tools for detection of LPR in combination with HMII.
  
  
  METHODS
  Tissue samples of hypopharynx, distal esophagus, and gastric cardia were collected from patients with LPR symptoms regardless of gastroesophageal reflux (GERD) diagnosis and underwent HMII to detect LPR and high esophageal reflux (HER: reflux 2 cm distal to upper esophageal sphincter) events. Patients were classified into two groups based on the presence of abnormal proximal exposure (APE), which was defined as LPR ≥1/day and/or HER ≥5/day: (1) positive-APE and (2) negative-APE. Patients with typical GERD symptoms without LPR symptoms who did not undergo HMII were used as a "control" GERD group. Protein was isolated from tissue samples and Western blot analysis of pepsin and Sep70 was performed. Pepsinogen was used as a control to differentiate pepsin from pepsinogen. Relative quantitation was performed using Image Studio Lite Software with normalization against the internal actin of each blot.
  
  
  RESULTS
  From October 2012 to September 2013, 55 patients underwent HMII. Of 55, 20 patients underwent biopsies from hypopharynx (17 positive-APE and 3 negative-APE). Ten patients with typical GERD symptoms were identified from tissue bank as a "control" GERD group. Pepsin was detected in distal esophagus and hypopharynx in all groups without significant difference among groups. However, Sep70 in distal esophagus and hypopharynx was significantly depleted in the positive-APE group compared to the other groups (p = 0.032 and 0.002, respectively).
  
  
  CONCLUSIONS
  Depletion of Sep70 with the presence of pepsin in the hypopharynx may indicate cellular injury in laryngopharynx due to constant proximal reflux. However, the normative data for these markers have to be validated.
authors.affiliation: Institute for the Treatment of Esophageal and Thoracic Disease, Allegheny Health Network, Pittsburgh, PA, USA.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Lori A
authors.initials: LA
authors.lastname: Kelly
authors.forename: Ali H
authors.initials: AH
authors.lastname: Zaidi
authors.forename: Christina L
authors.initials: CL
authors.lastname: Rotoloni
authors.forename: Juliann E
authors.initials: JE
authors.lastname: Kosovec
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Lloyd
authors.forename: Amina
authors.initials: A
authors.lastname: Waheed
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Hoppo
authors.forename: Blair A
authors.initials: BA
authors.lastname: Jobe
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D017097:Electric Impedance; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007013:Hypopharynx / Q000378:metabolism*; D057045:Laryngopharyngeal Reflux / Q000175:diagnosis* / Q000378:metabolism; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D010434:Pepsin A / Q000378:metabolism*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018840:HSP70 Heat-Shock Proteins; C533662:SEP70 protein, human; D010434:Pepsin A