Epithelial cell renewal and turnover and relationship to morphologic abnormalities in jejunal mucosa in tropical sprue.

A morphometric study confirmed that increasing severity of the jejunal mucosal morphologic lesion is accompanied by increased crypt height and reduced villus length in patients with tropical sprue. Mitotic activity in the crypts was increased. Pulse labeling of jejunal mucosal biopsies cultured in vitro with [3H]thymidine confirmed that there was increased uptake of label in tropical sprue with more rapid migration of labeled cells to the villi. The label was also lost more rapidly. Earlier ultrastructural studies have shown enterocyte damage and extrusion in the crypt and villus epithelium. The present data suggest that in the jejunal mucosa of patients with tropical sprue, the loss of damaged enterocytes leads to villus shortening and increased cell production in the crypts, with hypertrophy of the crypts.