Specificity of ultrastructural changes of small intestinal epithelium in early childhood.

Electron microscopical features of the small intestinal mucosa in 30 consecutive biopsies from 14 newly diagnosed coeliac patients, and 16 patients with chronic intermittent diarrhoea due to different causes, were studied. An attempt to define specific changes in each condition was made. An abnormal brush border, increased number of free ribosomes, rich rough endoplasmic reticulum, poorly developed smooth endoplasmic reticulum, large Golgi complexes, and thickened basal lamina were the most frequent findings in the coeliac biopsies. These changes suggest abnormal cellular metabolism, but as they were also observed in children with a variety of clinical conditions, they could not be specifically related to coeliac disease. These observations suggest that in small children different causes leading to different degrees of abnormal small intestinal mucosa, as observed with the light microscope, produce nonspecific changes of the cellular ultrastructure, which cannot be related to the degree of abnormality observed at the light microscope level.