title: Rapid salivary pepsin test: blinded assessment of test performance in gastroesophageal reflux disease.
abstract: OBJECTIVE
  Pepsin lateral flow device (LFD) is a rapid noninvasive test to detect salivary pepsin as a surrogate marker for gastroesophageal reflux disease (GERD). We aimed to establish the test sensitivity, specificity, positive and negative predictive values (PPV, NPV) in patients with symptomatic and objective evidence of GERD compared to healthy controls.
  
  
  METHODS
  Prospective, blinded, controlled cohort study.
  
  
  METHODS
  A total of 230 samples were analyzed. In vitro bench testing was conducted on 52 gastric juice and 54 sterile water samples to assess test sensitivity and specificity. Saliva was collected from 58 patients with GERD and 51 controls. All patients with GERD underwent esophagogastroduodenoscopy (EGD) and wireless 48-hour pH monitoring off acid suppressive therapy. PPV and NPV were calculated based on disease definition of esophagitis and/or abnormal pH monitoring.
  
  
  RESULTS
  Receiver operating characteristics analysis of in vitro samples found assay sensitivity and a specificity of 87%. There were 6/51 (12%) control subjects and 13/58 (22%) patients with GERD who tested positive for salivary pepsin (P = .25). There was a step-wise increase in the prevalence of positive salivary pepsin: esophagitis (55%), abnormal pH monitoring (43%), GERD symptoms only (24%) (P < .001). Salivary pepsin test showed a PPV of 81% and NPV of 78% for those with objective evidence of GERD (abnormal pH and/or esophagitis).
  
  
  CONCLUSIONS
  Rapid LFD for salivary pepsin has acceptable test characteristics in patients with GERD. A positive salivary pepsin test in this group may obviate the need for more expensive diagnostic testing by EGD or pH monitoring.
authors.affiliation: Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee 37232-5280, USA.
authors.forename: Elif
authors.initials: E
authors.lastname: Saritas Yuksel
authors.forename: Shih-Kuang S
authors.initials: SK
authors.lastname: Hong
authors.forename: Vicki
authors.initials: V
authors.lastname: Strugala
authors.forename: James C
authors.initials: JC
authors.lastname: Slaughter
authors.forename: Marion
authors.initials: M
authors.lastname: Goutte
authors.forename: C Gaelyn
authors.initials: CG
authors.lastname: Garrett
authors.forename: Peter W
authors.initials: PW
authors.lastname: Dettmar
authors.forename: Michael F
authors.initials: MF
authors.lastname: Vaezi
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D050782:Esophageal pH Monitoring; D004945:Esophagoscopy / Q000379:methods; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D005773:Gastroscopy / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D010434:Pepsin A / Q000032:analysis*; D011446:Prospective Studies; D012016:Reference Values; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D010434:Pepsin A