Loss of the glycocalyx of enterocytes in small intestine: a feature detected by scanning electron microscopy in children with gastrointestinal intolerance to dietary protein.
Observations are reported on biopsied small bowel mucosa by scanning and transmission electron microscopy in 10 infants and children with chronic diarrhea and intolerance to dietary protein(s). The most striking and consistent finding was widespread loss of glycocalyx from the surface of enterocytes, exposing the tips of the microvilli. Concomitantly, disaccharidase activities were markedly depressed in nine of the 10 patients, and such enzyme activities showed a tendency to return toward normal after removal of the offending dietary antigen(s) in concert with efforts to rebuild the glycocalyx. By light microscopy, no discernible structural damage was seen in eight of the 10 patients; two showed blunting of villi, but there was also loss of glycocalyx. The pathogenesis of the loss of the glycocalyx is unknown. Its finding is rather unique, because it has not been observed in any other condition characterized by chronic diarrhea in children. It is possible that the loss of the glycocalyx is a sequel to cell damage by a hitherto not defined interaction between host and dietary protein. Immunologic processes may be involved.
Poley
J R
JR
Department of Pediatrics, Eastern Virginia Medical School, Norfolk 23507.
D002675:Child, Preschool; D002908:Chronic Disease; D003967:Diarrhea / Q000209:etiology; D004044:Dietary Proteins / Q000009:adverse effects*; D004186:Disaccharidases / Q000172:deficiency; D005260:Female; D005512:Food Hypersensitivity / Q000201:enzymology / Q000473:pathology*; D006023:Glycoproteins / Q000172:deficiency*; D006801:Humans; D007223:Infant; D007413:Intestinal Mucosa / Q000201:enzymology / Q000648:ultrastructure*; D007421:Intestine, Small / Q000201:enzymology / Q000648:ultrastructure*; D008297:Male; D008855:Microscopy, Electron, Scanning; D011134:Polysaccharides / Q000172:deficiency*
D004044:Dietary Proteins; D006023:Glycoproteins; D011134:Polysaccharides; D004186:Disaccharidases