bromochloroacetic-acid and Ileitis

M cells play an important role in the intestinal immune system as they have a high capacity for transcytosis of a wide range of microorganisms and macromolecules. However, little is known about the role of M cells during intestinal inflammation.. We studied M cell development during indomethacin-induced intestinal inflammation in rats.. Ileitis in rats was induced by two subcutaneous injections with indomethacin (7.5 mg/kg) given 24 h apart. Rats were sacrificed after 14 days and tissue was analysed by fluorescence microscopy and electron microscopy. M cells could be visualized by using the FITC-labelled mAb anti-cytokeratin (CK)-8 (clone 4.1.18), which was recently identified as specific M cell marker in rats. The number of cytokeratin-8 positive M cells was related to the surface of the follicle associated epithelium. For morphological studies, we used both transmission electron microscopy (T.E.M.) and scanning electron microscopy (S.E.M.).. In non-inflamed ileum M cells were scarce. Only 4% of the follicle associated epithelium were M cells, whereas an increase of M cells up to 11% was found in inflamed follicle associated epithelium (P < 0.001). The rate of M cell induction depended on the macroscopic degree of inflammation. T.E.M./S.E.M. studies showed that in inflamed tissue most M cells underwent apoptosis with typical morphological signs. In contrast to apoptotic M cells, the neighbouring enterocytes usually appeared intact. The number of mononuclear cells below the follicle associated epithelium was significantly increased. S.E.M. studies revealed that during induced ileitis mononuclear cells migrated from the lamina propria into the gut lumen by passing through apoptotic M cells.. During indomethacin-induced ileitis in rats the increase in M cell number in association with apoptosis of M cells may alter the intestinal barrier function. These observations may play a pivotal role in the pathogenesis of chronic intestinal inflammation, e.g. in inflammatory bowel disease.

Topics: Animals; Apoptosis; Biomarkers; Cell Movement; Epithelial Cells; Epithelium; Female; Fluorescein-5-isothiocyanate; Ileitis; Immunochemistry; In Vitro Techniques; Indomethacin; Keratins; Leukocytes, Mononuclear; Microscopy, Electron; Microscopy, Fluorescence; Peyer's Patches; Rats; Rats, Wistar

We present two cases of small-bowel adenocarcinoma and dysplasia in patients with longstanding Crohn's disease. In one case, the dysplasia and cancer were exclusively located in the terminal ileum, whereas in the other case, several cancers were found from the ileum toward the transverse colon. In both cases, we found a clinically unsuspected Dukes C1 mucinous adenocarcinoma together with large foci of polypoid villous dysplasia or with multifocal high-grade dysplasia and intramucosal carcinoma. Immunohistochemical staining for carcinoembryonic antigen (CEA) revealed a different staining pattern in various diseased areas. The intensity of CEA staining paralleled the histologic degrees of dysplasia and neoplasia. Cytokeratin expression was disturbed in inflamed mucosa, and it was more pronounced in high-grade dysplasia and invasive carcinoma. We conclude that the presence of dysplasia in an intestinal biopsy of a patient with Crohn's disease should arouse the pathologist's suspicion of carcinoma and force him or her to take multiple sections from strictures and polypoid lesions, especially since the clinical symptoms of a carcinoma may be obscured by the symptoms of inflammatory bowel disease. Immunohistochemical staining with CEA and cytokeratin are useful in the objectivation of dysplasia.

Topics: Adenocarcinoma; Adult; Carcinoembryonic Antigen; Colitis; Colonic Neoplasms; Crohn Disease; Female; Humans; Ileal Neoplasms; Ileitis; Intestinal Mucosa; Keratins; Male; Middle Aged; Neoplasm Invasiveness