title: Increased HLA-DR expression on tissue eosinophils in eosinophilic esophagitis.
abstract: OBJECTIVE
  The aim of the study was to investigate whether eosinophils have increased human leukocyte antigen (HLA)-DR expression in subjects with eosinophilic esophagitis (EoE) compared with controls.
  
  
  METHODS
  Patients who were undergoing an upper endoscopy with biopsies for suspected gastroesophageal reflux disease (GERD) or EoE at Lucile Packard Children's Hospital were enrolled. In total, the blood and tissue samples of 10 healthy controls (HC), 11 subjects with GERD, and 10 with EoE were studied. Multiple tissue staining to identify eosinophils (via eosinophil cationic protein-clone EG2) and major histocompatibility complex class II cell surface receptors (via HLA-DR) was performed via immunohistochemistry. The peripheral blood was analyzed using flow cytometry to detect eosinophil HLA-DR expression among these subjects.
  
  
  RESULTS
  In the tissue, a greater proportion of eosinophils expressed HLA-DR among the subjects with EoE (mean 0.83 +/- 0.14, n = 9) relative to those with GERD (mean 0.18 +/- 0.19, n = 8, P < 0.01) and HC (mean 0.18 +/- 0.13, n = 6, P < 0.01). In total, 6 participants (4 HC subjects and 2 subjects with GERD) did not have any eosinophils identified on tissue staining and were unable to be included in the present statistical analysis. In the blood, there was no statistically significant difference in eosinophil HLA-DR expression among HC subjects (mean 415 +/- 217, n = 6), subjects with GERD (mean 507 +/- 429, n = 2), and those with EoE (mean 334 +/- 181, n = 6).
  
  
  CONCLUSIONS
  These data demonstrate that the eosinophils from the esophagus of subjects with EoE have increased HLA-DR expression within this tissue.
authors.affiliation: Lucile Packard Children's Hospital, Stanford University, Palo Alto, CA, USA. drajpatel@gmail.com
authors.forename: Anup J
authors.initials: AJ
authors.lastname: Patel
authors.forename: Judy
authors.initials: J
authors.lastname: Fuentebella
authors.forename: Yael
authors.initials: Y
authors.lastname: Gernez
authors.forename: Tammie
authors.initials: T
authors.lastname: Nguyen
authors.forename: Dorsey
authors.initials: D
authors.lastname: Bass
authors.forename: William
authors.initials: W
authors.lastname: Berquist
authors.forename: Kenneth
authors.initials: K
authors.lastname: Cox
authors.forename: Eric
authors.initials: E
authors.lastname: Sibley
authors.forename: John
authors.initials: J
authors.lastname: Kerner
authors.forename: Kari
authors.initials: K
authors.lastname: Nadeau
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D057765:Eosinophilic Esophagitis / Q000276:immunology* / Q000378:metabolism; D004804:Eosinophils / Q000276:immunology / Q000378:metabolism*; D004947:Esophagus / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005764:Gastroesophageal Reflux / Q000276:immunology* / Q000378:metabolism; D006684:HLA-DR Antigens / Q000378:metabolism*; D006801:Humans; D007223:Infant; D008297:Male; D055815:Young Adult
chemical_list: D006684:HLA-DR Antigens