Cytokeratin and CDX-2 expression in Barrett's esophagus.
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.
van Baal
Jantine W P M
JW
Center for Experimental Molecular Medicine in Amsterdam, University Medical Center Utrecht, The Netherlands. j.w.p.m.vanbaal-2@umcutrecht.nl
Bozikas
Andreas
A
Pronk
Rick
R
Ten Kate
Fibo J W
FJ
Milano
Francesca
F
Rygiel
Agnieszka M
AM
Rosmolen
Wilda D
WD
Peppelenbosch
Maikel P
MP
Bergman
Jacques J G H M
JJ
Krishnadath
Kausilia K
KK
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
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