Studies of intestinal lymphoid tissue. VIII. Use of epithelial lymphocyte mitotic indices in differentiating untreated celiac sprue mucosa from other childhood enteropathies.

The mitotic activity of epithelial lymphocytes (expressed as percentage mitotic figures/3,000 lymphocytes/mucosal biopsy) was determined in a random sample of jejunal biopsies performed on 44 children with malabsorption, diarrhoea, or failure to thrive. The mitotic index (MI) exceeded 0.2% in 19 biopsies obtained from children with untreated celiac sprue (CS); there were no false positives. The remaining 25 biopsies (MI of less than 0.2%) were considered to be "nonceliac" in origin, among which were several with a severe degree of villous flattening. Conditions in this latter category excluded by a low MI included cow's milk protein enteropathy, selective immunoglobulin A deficiency, combined variable immunodeficiency, Crohn's jejunitis, and intractable diarrhoea of infancy. A high MI (greater than 0.2%) prospectively distinguishes mucosal lesions due to untreated CS from other causes of malabsorption, particularly those associated with villous flattening, but in which the MI is less than 0.2%. This index is therefore proposed as a simple, reliable, and prospective histological marker of CS, and one that could: reduce the need to perform multiple biopsies during a gluten-free diet; and avoid the necessity for follow-up "diagnostic" gluten challenges, especially in very young children.