title: Role of extra-esophageal reflux in chronic otitis media with effusion.
abstract: OBJECTIVE
  Otitis media with effusion (OME) is the most common cause of childhood hearing loss. Despite its prevalence, the enormous health care expenditures resulting from its treatment, and the increasing therapeutic challenges imposed by antimicrobial resistance, very little is known regarding the cellular and molecular immunologic and inflammatory events in this disease process. Extra-esophageal reflux (EER) has been implicated in the pathogenesis of chronic OME. The objective of this study was to confirm that children with OME have EER into the middle ear as measured by the presence of pepsin in middle ear effusions (MEE) removed during tympanostomy tube (TT) placement.
  
  
  METHODS
  Prospective, translational, cell biological research study.
  
  
  METHODS
  MEE were obtained from children undergoing TT placement for OME. The fluid was lysed in a urea buffer and the presence of pepsin quantitatively determined by Western blot analysis using a specific antipepsin antibody. The pH of the samples was recorded before lysis.
  
  
  RESULTS
  Pepsin protein was detected in 18 of 32 (56%) samples analyzed, with 12 of 20 (60%) patients having at least one positive sample for pepsin. Pepsin levels ranged from 80 to 1,000 ng/mL. The pH of the samples ranged from 6.0 to 7.6, with a mean pH of 6.8.
  
  
  CONCLUSIONS
  Pepsin was detected in 60% of patients with OME, confirming that EER into the middle ear occurs in these children. The pepsin present would have little or no activity at pH 6.0 to 7.6; however, pepsin is stable below pH 8.0 and thus could be reactivated after a decrease in pH.
authors.affiliation: Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Crapko
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Kerschner
authors.forename: Michael
authors.initials: M
authors.lastname: Syring
authors.forename: Nikki
authors.initials: N
authors.lastname: Johnston
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D008297:Male; D013058:Mass Spectrometry; D008876:Middle Ear Ventilation / Q000379:methods*; D010034:Otitis Media with Effusion / Q000209:etiology* / Q000378:metabolism / Q000601:surgery; D010434:Pepsin A / Q000276:immunology / Q000378:metabolism; D011446:Prospective Studies; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D010434:Pepsin A