title: Pepsin and carbonic anhydrase isoenzyme III as diagnostic markers for laryngopharyngeal reflux disease.
abstract: OBJECTIVE
  The objective was to investigate the potential use of pepsin and carbonic anhydrase isoenzyme III (CA-III) as diagnostic markers for laryngopharyngeal reflux disease.
  
  
  METHODS
  Prospective cell biological investigation was conducted of laryngeal biopsy specimens taken from 9 patients with laryngopharyngeal reflux disease and 12 normal control subjects using antibodies specific for human pepsin (produced in the authors' laboratory within the Department of Otolaryngology at Wake Forest University Health Sciences, Winston-Salem, NC) and CA-III.
  
  
  METHODS
  Laryngeal biopsy specimens were frozen in liquid nitrogen for Western blot analysis and fixed in formalin for pepsin immunohistochemical study. Specimens between two groups (patients with laryngopharyngeal reflux disease and control subjects) were compared for the presence of pepsin. Further analyses investigated the correlation between pepsin, CA-III depletion, and pH testing data.
  
  
  RESULTS
  Analysis revealed that the level of pepsin was significantly different between the two groups (P < .001). Secondary analyses demonstrated that presence of pepsin correlated with CA-III depletion in the laryngeal vocal fold and ventricle (P < .001) and with pH testing data in individuals with laryngopharyngeal reflux disease.
  
  
  CONCLUSIONS
  Pepsin was detected in 8 of 9 patients with laryngopharyngeal reflux disease, but not in normal control subjects (0 of 12). The presence of pepsin was associated with CA-III depletion in the laryngeal vocal fold and ventricle. Given the correlation between laryngopharyngeal reflux disease and CA-III depletion, it is highly plausible that CA-III depletion, as a result of pepsin exposure during laryngopharyngeal reflux, predisposes laryngeal mucosa to reflux-related inflammatory damage.
authors.affiliation: Center for Voice and Swallowing Disorders, Department of Otolaryngology, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27157-1034, U.S.A. njohnsto@wfubmc.edu
authors.forename: Nikki
authors.initials: N
authors.lastname: Johnston
authors.forename: John
authors.initials: J
authors.lastname: Knight
authors.forename: Peter W
authors.initials: PW
authors.lastname: Dettmar
authors.forename: Mark O
authors.initials: MO
authors.lastname: Lively
authors.forename: Jamie
authors.initials: J
authors.lastname: Koufman
mesh_terms: D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D015153:Blotting, Western; D024403:Carbonic Anhydrase III / Q000032:analysis / Q000378:metabolism*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004591:Electrophoresis, Polyacrylamide Gel; D004942:Esophagitis, Peptic / Q000201:enzymology* / Q000473:pathology; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism; D007820:Laryngeal Mucosa / Q000201:enzymology / Q000473:pathology; D008297:Male; D010434:Pepsin A / Q000032:analysis / Q000378:metabolism*; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D046509:Tissue Culture Techniques
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D010434:Pepsin A; D024403:Carbonic Anhydrase III