Distribution of cell adhesion molecules in infants with intestinal epithelial dysplasia (tufting enteropathy)

Background and Aims: Intestinal epithelial dysplasia, or tufting enteropathy, is a newly described clinicopathologic entity with refractory diarrhea in infants. Histological abnormalities include villous atrophy, disorganization of the surface epithelium, and basement membrane abnormalities. The aim of this study was to examine defects in intestinal epithelial cell adhesion, differentiation, or proliferation in the pathogenesis of epithelial dysplasia. Methods: Histological, immunohistochemical, and ultrastructural characteristics of epithelial dysplasia in a group of 6 children were compared with those groups with normal small bowel and other villous atrophy (celiac sprue and microvillous inclusion disease). Distribution of adhesion molecules, markers of cell polarization and proliferation, and the phenotype of intraepithelial lymphocytes 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 α₂β₁ integrin along the crypt-villus axis, increased immunohistochemical expression of desmoglein, and ultrastructural changes of desmosomes increased in length and number. No evidence for abnormalities in epithelial cell polarization, proliferation, or T-cell activation was found. Conclusions: This study strongly suggests a role played by alterations of cell-cell and cell-matrix interactions in the pathogenesis of epithelial dysplasia.