ABSTRACT
INTRODUCTION: Carcinoembryonic antigen (CEA) is a cell surface glycoprotein and member of immunoglobuline superfamily. Recent studies pointed out that this glycoprotein also belonged to the family of intercellular adhesive molecules (ICAMs). The presence and increased expression of CEA is noticed in chronic inflammation of the skin, gall bladder and extrahepatic biliary tract. According to our knowledge, this glycoprotein has not been studied previously in chronic inflammations of the middle ear mucosa. The purpose of this study was to investigate the presence and distribution of carcinoembryonic antigen (CEA) in chronic otitis media with cholesteatoma. MATERIALS AND METHODS: The immunohistochemical analysis with high affinity monoclonal antibodies against human carcinoembryonic antigen (MEDIX Bochemica AB, Finland) was performed in 71 mucosal samples with chronic inflammation and in 8 samples of the clinically healthy middle ear mucosa. The mucosal specimens were taken intraoperatively from different regions of the middle ear cleft during surgery of chronic otitis media with cholesteatoma. The control samples were obtained during surgery of traumatic perforation of the ear drum. For control staining irrelevant monoclonal antibodies were used (Anti-h-PRL clone code 5601: OY Medix Biochemica AB, Finland). The complex antibody-CEA antigen was visualized by marked Ig mice antibody (HRPO Inep, Zemun) and diaminobenzidine (DAB) as chromogene. After being prepared through this specific immunohistochemical analysis, all mucosal specimens were analysed under the light microscope. RESULTS: Carcinoembryonic antigen (CEA) was not detected in non-inflamed, clinically healthy mucosal specimens of the middle ear mucosa. The 71 samptes taken from mastoid, attic, promontory and protympanon in chronic otitis media with cholesteatoma showed positive staining for CEA expression in 56 (79%) biopsy specimens, while in 15 (21%) CEA has not been identified. CEA was present in squamous epithelium of cholesteatoma, then in fibrous stroma and in endothelial cells of blood vessels of the lamina propria in the middle ear mucosa. DISCUSSION: Chronic otitis media with cholesteatoma is an invasive disease with aggressive destruction of mucosal and bony structures of the middle ear. The pathophysiological mechanism of that kind of chronic inflammation has not been clarified. Studies which analysed excessive expression of CEA in chronic inflammation of the skin pointed out that CEA may induce hyperproliferation of keratinocytes. The findings in our study confirmed the high level of expression of CEA in squamous epithelium of the middle ear cholesteatoma. The endothelial cells of blood vessels and stroma of lamina propria, as well as stroma of the granulation tissue were stained positively with labelled CEA antibodies. The results of this study showed that CEA was present in chronic inflammation of the middle ear mucosa and in the squamous epithelium of cholesteatoma. The precise function of the increased expression of CEA in chronic otitis media with cholesteatoma will be the subject of our further studies.
