Cytokeratin profile suggests metaplastic epithelial transformation in Barrett's oesophagus.

Cytokeratins are subunit proteins of epithelial cell intermediate filaments, which are genetically determined. Because epithelia have their own characteristic cytokeratin profile, this may reveal the origin of the epithelium. The cytokeratin profile of Barrett's oesophagus, complicating severe gastro-oesophageal reflux disease, was determined in 35 consecutive patients and in 10 normal controls in order to provide insight into the origin of Barrett's epithelium. Immunostaining of frozen sections showed abundant immunoactivity for cytokeratin (CK) 13, which is characteristic of squamous epithelia, including that of the oesophagus, but is not present in the simple columnar epithelium of the cardia. On the other hand, the latter epithelium expresses mainly CK 8, 18 and 19, also found in Barrett's epithelium. The presence of CK 13 in Barrett's epithelium may indicate its origin from the squamous oesophageal epithelium and not from the proximal migration of columnar epithelial cells of the gastric cardia.