DISTRIBUTION OF CELL-ADHESION MOLECULES IN INFANTS WITH INTESTINAL EPITHELIAL DYSPLASIA (TUFTING ENTEROPATHY)

Background & Aims: Intestinal epithelial dysplasia, or tufting enterop athy, is a newly described clinicopathologic entity with refractory di arrhea in infants, Histological abnormalities include villous atrophy, disorganization of the surface epithelium, and basement membrane abno rmalities. The aim of this study was to examine defects in intestinal epithelial cell adhesion, differentiation, or proliferation in the pat hogenesis of epithelial dysplasia. Methods: Histological, immunohistoc hemical, and ultrastructural characteristics of epithelial dysplasia i n a group of 6 children were compared with those groups with normal sm all bower and other villous atrophy (celiac sprue and microvillous inc lusion disease). Distribution of adhesion molecules, markers of cell p olarization and proliferation, and the phenotype of intraepithelial ly mphocytes were determined. Results: Alterations suggestive of abnormal cell-cell and cell-matrix interactions were present in patients with epithelial dysplasia. They included abnormal distribution of alpha(2) beta 1 integrin along the crypt-villus axis, increased immunohistochem ical expression of desmoglein, and ultrastructural changes of desmosom es increased in length and number. No evidence for abnormalities in ep ithelial cell polarization, proliferation, or T-cell activation was fo und. Conclusions: This study strongly suggests a role played by altera tions of cell-cell and cell-matrix interactions in the pathogenesis of epithelial dysplasia.