DETECTION OF A SHARED COLON EPITHELIAL EPITOPE ON BARRETT EPITHELIUM BY A NOVEL MONOCLONAL-ANTIBODY

Objective: To determine if there is a reactive epitope common to colon ic epithelium and Barrett epithelium, a premalignant metaplastic colum nar-lined esophagus, usually arising as a complication of chronic refl ux esophagitis. Design: A monoclonal antibody, 7E(12)H(12) (IgM isotyp e), developed against a colonic epithelial protein was used in a sensi tive immunoperoxidase assay using formalin-fixed, paraffin-embedded ti ssue. One hundred sixteen tissue specimens from the esophagus, stomach , duodenum, and jejunum were examined. Twenty-two biopsy specimens wer e taken from 22 patients with benign Barrett epithelium, and 12 specim ens were obtained from 12 patients with adenocarcinoma of the esophagu s arising in Barrett epithelium. The remaining 85 tissue specimens wer e obtained from various parts of the upper gastrointestinal tract of p atients with or without disease states. Results: 21 of 22 (95%) Barret t epithelium specimens and all 12 adenocarcinomas arising from Barrett epithelium reacted with the 7E(12)H(12) monoclonal antibody. Other ti ssues from esophagus, gastroesophageal junction, stomach, duodenum, or jejunum did not react. Squamous cell carcinoma of the esophagus also did not react. Conclusions: Barrett epithelium shares phenotypic expre ssion of colonic epithelium. The 7E(12)H(12) monoclonal antibody may p rovide insight into the origin and cellular lineage of Barrett epithel ium.