Immunohistochemical markers for Barrett's esophagus and associations to esophageal Z-line appearance

Background: Data from previous studies on intestinal metaplasia at the gast roesophageal junction have been conflicting, which makes the diagnosis of B arrett's esophagus less obvious. This may partly be due to the lack of a re liable classification of the Z-line appearance. We previously proposed such a classification (the ZAP classification) that was shown to correlate with the prevalence of intestinal metaplasia. The use of different immunohistoc hemical techniques has increased in the: study of intestinal metaplasia. In the present study our aim was to 1) evaluate the impact of different antib odies, namely cytokeratin (CK) 7, 13, and 20, CaCO3/73, and FBB2/29, in ord er to differentiate between Barrett's esophagus and cardia intestinal metap lasia, and 2) explore the staining patterns in different ZAP grades. Method s: Thirty-nine specimens with intestinal metaplasia were compared-9 from Ba rrett's esophagus, 6 from cardia, and 24 from the Z-line. The Z-line specim ens were evaluated with respect to ZAP grade. Results: No differences were encountered regarding staining patterns for CK 13 and CaCO3/73 in Barrett's esophagus and cardia. The staining pattern of CK7/20 was significantly dif ferent between Barrett's esophagus and cardia. CK7/20 showed a rising frequ ency of Barrett's esophagus staining pattern with rising ZAP grade. Conclus ion: CK7/20 is a feasible marker for Barrett's esophagus. Intestinal metapl asia in different ZAP grades differs regarding expression of immunohistoche mical markers.