EPITHELIAL PROLIFERATION AND DIFFERENTIATION IN FLAT DUODENAL MUCOSA OF PATIENTS WITH FAMILIAL ADENOMATOUS POLYPOSIS

The colonic mucosa in patients with familial adenomatous polyposis (FAP) exhibits altered epithelial cell proliferation, differentiation, and mucin histochemical properties compared with unaffected controls. However, Little is known regarding Obese parameters in FAP-associated duodenal mucosa, an area in which adenomas also develop at a high rate. The purpose of this study is to evaluate the morphologic, mucin histochemical, and proliferative characteristics of the epithelium in the flat duodenal mucosa from 32 patients with FAP (18 with and 14 without adenomas), and compare the results with those observed in 18 non-FAP age-matched controls. The proliferative properties of the epithelium were analyzed immunohistochemically with the MIB-1 antibody, which recognizes the Ki-67 proliferation-associated nuclear antigen in formalin-fixed tissue. No significant differences were detected with regard to the mucin histochemical properties (sialomucins, sulfomucins, and o-acylated sialomucins) or the proliferative characteristics of the duodenal epithelium in FAP versus non-FAP controls. However, FAP-associated duodenal epithelium showed a significant increase in the number of Paneth cells (P = 0.04) and endocrine cells (P = 0.01) per crypt in comparison with controls. This specialized cell hyperplasia occurred in the flat mucosa of FAP patients regardless of the presence or absence of adenomas and may represent a primary defect in the regulation of stem cell differentiation in the duodenum in FAP.