title: Cytokeratin and CDX-2 expression in Barrett's esophagus.
abstract: OBJECTIVE
  Barrett's esophagus (BE) is a premalignant condition of the distal esophagus. For diagnostic purposes it is important to find biomarkers that can specifically identify BE, for instance to differentiate BE epithelial cells from gastric cardia epithelial cells in brush cytology specimens. The objective of this study was to determine the specificity of CDX-2 and a set of cytokeratins (CKs) as specific markers for BE as compared with normal squamous esophageal and gastric cardia tissue.
  
  
  METHODS
  Immunohistochemistry (IHC) with specific antibodies against CDX-2, and a set of CKs was performed on fresh frozen consecutive tissue sections of normal squamous, gastric cardia and non-dysplastic BE of 80 patients.
  
  
  RESULTS
  IHC results showed CK8, CK18 and CK20 expression in both BE and gastric cardia, while CK7 was seen in all BE but also in 26% of gastric cardia biopsies. CK10/13 was only expressed in normal squamous epithelium. CDX-2 nuclear staining was found in 87.5% of the BE biopsies, whereas normal squamous esophagus and cardia biopsies were negative.
  
  
  CONCLUSIONS
  CDX-2 in combination with a set of CKs can be used as biomarkers to distinguish between BE and normal squamous esophagus. In order to distinguish BE from cardia tissue, a combination of CDX-2 and CK7 is most informative.
authors.affiliation: Center for Experimental Molecular Medicine in Amsterdam, University Medical Center Utrecht, The Netherlands. j.w.p.m.vanbaal-2@umcutrecht.nl
authors.forename: Jantine W P M
authors.initials: JW
authors.lastname: van Baal
authors.forename: Andreas
authors.initials: A
authors.lastname: Bozikas
authors.forename: Rick
authors.initials: R
authors.lastname: Pronk
authors.forename: Fibo J W
authors.initials: FJ
authors.lastname: Ten Kate
authors.forename: Francesca
authors.initials: F
authors.lastname: Milano
authors.forename: Agnieszka M
authors.initials: AM
authors.lastname: Rygiel
authors.forename: Wilda D
authors.initials: WD
authors.lastname: Rosmolen
authors.forename: Maikel P
authors.initials: MP
authors.lastname: Peppelenbosch
authors.forename: Jacques J G H M
authors.initials: JJ
authors.lastname: Bergman
authors.forename: Kausilia K
authors.initials: KK
authors.lastname: Krishnadath
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000378:metabolism* / Q000473:pathology*; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D000071616:CDX2 Transcription Factor; D002299:Cardia / Q000378:metabolism / Q000473:pathology; D004947:Esophagus / Q000378:metabolism / Q000473:pathology; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D053535:Keratin-13 / Q000378:metabolism; D053538:Keratin-18 / Q000378:metabolism; D053554:Keratin-20 / Q000378:metabolism; D053533:Keratin-8 / Q000378:metabolism; D007633:Keratins / Q000378:metabolism*; D008875:Middle Aged; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology
chemical_list: D015415:Biomarkers; D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; D053535:Keratin-13; D053538:Keratin-18; D053554:Keratin-20; D053533:Keratin-8; D007633:Keratins