title: Cytokeratin 7/20 and MUC1, 2, 5AC, and 6 expression patterns in Barrett's esophagus and intestinal metaplasia of the stomach: intestinal metaplasia of the cardia is related to Barrett's esophagus.
abstract: Intestinal metaplasia (IM) in endoscopic biopsies obtained from close to the gastroesophageal junction may represent IM of the cardia (CIM) or Barrett's esophagus (BE), which have different malignant potentials despite similar morphology. This study compared cytokeratin (CK) 7/20 and mucin (MUC1, 2, 5AC, and 6) immunopatterns in biopsies from BE (n = 41), CIM (n = 35), and antral gastric IM (AIM, n = 37) to evaluate their roles as diagnostic aids. CK7 and CK20 expression was described as absent, patchy (superficial and deep), continuous superficial only, continuous deep only, and diffuse. Eleven different combinations of CK7/20 expression were seen. Since CK20 staining was positive in all cases, four main patterns were defined on the basis of the observed CK7 staining as 1, absent; 2, patchy (superficial and/or deep); 3, diffuse; and 4, continuous superficial only. Overall CK7 positivity (regardless of pattern) was higher in BE and CIM than in AIM. CK patterns 3 and 4 were also higher in BE and CIM than in AIM. For either pattern 3 or 4, the positive and negative predictive values for BE versus AIM were 95% and 67%, respectively. MUC1 was rarely expressed in BE and CIM compared with AIM, whereas the opposite was noted for MUC5AC expression. MUC2 and MUC6 expression was similar in all locations. In conclusion, diffuse or continuous superficial CK7 staining is highly characteristic of BE and CIM and contrasts with AIM. It is, however, not very sensitive. CK20 profiles have no added value. Mucin expression also differs between BE and CIM versus AIM, but the specificity of any pattern is insufficient for distinction in individual cases. Importantly, CK and MUC expression patterns in BE and CIM are virtually indistinguishable, limiting their use in this differential and raising the question of whether they are biologically related.
authors.affiliation: Department of Pathology, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin. cgulmann@rcsi.ie
authors.forename: Christian
authors.initials: C
authors.lastname: Gulmann
authors.forename: Omar Al
authors.initials: OA
authors.lastname: Shaqaqi
authors.forename: Antoinette
authors.initials: A
authors.lastname: Grace
authors.forename: Mary
authors.initials: M
authors.lastname: Leader
authors.forename: Stephen
authors.initials: S
authors.lastname: Patchett
authors.forename: David
authors.initials: D
authors.lastname: Butler
authors.forename: Elaine
authors.initials: E
authors.lastname: Kay
mesh_terms: D001471:Barrett Esophagus / Q000473:pathology*; D015415:Biomarkers / Q000032:analysis; D003937:Diagnosis, Differential; D020869:Gene Expression Profiling; D006801:Humans; D007381:Intermediate Filament Proteins / Q000032:analysis; D007422:Intestines / Q000473:pathology*; D053554:Keratin-20; D053552:Keratin-7; D007633:Keratins / Q000032:analysis*; D008679:Metaplasia / Q000473:pathology; D055271:Mucin 5AC; D018396:Mucin-1 / Q000032:analysis*; D055262:Mucin-2; D055272:Mucin-6; D009077:Mucins / Q000032:analysis; D012189:Retrospective Studies; D013270:Stomach / Q000473:pathology*
chemical_list: D015415:Biomarkers; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; C507497:KRT7 protein, human; D053554:Keratin-20; D053552:Keratin-7; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; C524734:MUC6 protein, human; D055271:Mucin 5AC; D018396:Mucin-1; D055262:Mucin-2; D055272:Mucin-6; D009077:Mucins; D007633:Keratins