title: Comparison of eotaxin-3 biomarker in patients with eosinophilic oesophagitis, proton pump inhibitor-responsive oesophageal eosinophilia and gastro-oesophageal reflux disease.
abstract: BACKGROUND
  Proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) is a recently described entity which resembles oeosinophilic oesophagitis (EoE), yet responds to acid suppressive treatment.
  
  
  OBJECTIVE
  To determine whether EoE shares similar staining features with PPI-REE or with gastro-oesophageal reflux disease (GERD).
  
  
  METHODS
  This retrospective study consisted of patients with an established diagnosis of EoE, PPI-REE, or GERD identified from a database during a 1-year period. Immunohistochemistry (IHC) analysis was performed specifically targeting eotaxin-3 antibodies. All sections were qualitatively (intensity) and quantitatively (percentage of cells stained) assessed independently by two blinded pathologists.
  
  
  RESULTS
  The cohort consisted of three groups of patients: EoE (n = 22), PPI-REE (n = 23) and GERD (n = 23) for a total of 68 patients. Study demographics included mean age 39 (14) years, 75% male and 77% Caucasian. There was a significant difference in the eotaxin-3 staining among EoE, PPI-REE and GERD groups [mean score (s.d.): 1.2 (1.2), 0.8 (1.0), 0.3 (0.7), P = 0.006]. Staining scores of EoE patients were significantly higher compared with GERD (P = 0.002) and a trend towards significance was seen between EoE and PPI-REE (P = 0.054). There was also a significant difference in EoE staining intensity score among the three groups (P = 0.006). Intensity scores of EoE were significantly higher compared with GERD [1.0 (0.9) vs. 0.22 (0.52), P < 0.001]. There was no significant difference between EoE and PPI-REE groups [1.0 (0.0) vs. 0.52 (0.75) P = 0.094].
  
  
  CONCLUSIONS
  A difference in eotaxin-3 staining was seen in the three groups of patients with oesophageal eosinophilia. Eotaxin-3 can distinguish EoE from GERD, but not from proton pump inhibitor responsive-oesophageal eosinophilia.
authors.affiliation: Gastroenterology Service, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: F J
authors.initials: FJ
authors.lastname: Moawad
authors.affiliation: Department of Pathology, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Wells
authors.affiliation: Department of Pathology, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Johnson
authors.affiliation: Department of Research Programs, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Reinhardt
authors.affiliation: Gastroenterology Service, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Maydonovitch
authors.affiliation: Department of Pathology, Walter Reed National Military Medical Center, Bethesda, MD, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Baker
mesh_terms: D000328:Adult; D015415:Biomarkers; D000075906:Chemokine CCL26; D019742:Chemokines, CC / Q000276:immunology*; D003937:Diagnosis, Differential; D057765:Eosinophilic Esophagitis / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; C120429:CCL26 protein, human; D000075906:Chemokine CCL26; D019742:Chemokines, CC; D054328:Proton Pump Inhibitors