Increased expression of metallothionein in inflammatory bowel disease.

Abstract

Metallothioneins (MT) are cytoprotective against the damaging effects of oxygen-derived free radicals. Therefore MT may be involved in defence mechanisms to counter Crohn's disease (CD) and ulcerative colitis (UC). 107 routinely processed tissue samples from 22 patients with CD and 48 patients with UC were tested with the monoclonal anti-MT antibody E9. Immunohistochemistry was used to assess MT staining in a semiquantitative manner. Chi-square test was used for statistical analysis. MT overexpression was found in the fibroblasts of all ulcerative and/or fissural lesions in UC and CD. MT overexpression in intestinal epithelial cells of 40% of UC and CD lesions correlated significantly with the grade of inflammation. MT-immunoreactivity in fibroblasts supports a protective role for MT in inflammatory bowel disease. It remains unclear whether MT overexpression in epithelial cells is also important in this protection.