IMMUNOHISTOCHEMICAL INVESTIGATION OF MIDDLE EAR MUCOSA IN OTITIS MEDIA WITH EFFUSION

Abstract

In this paper, middle ear mucosa obtained from the patients with of otitis media with effusion mucous type was examined immunohistochemically. Histopathological features of middle ear mucosa from there patients were characterized by the hypersecretion of mucous membrane and various inflammatory infiltrations in the submucosal connective tissue. Monoclonal antibody against the cell surface antigen demonstrated the accumulation of B cells and Leu 3a positive helper/inducer T cells in the submucosal connective tissue forming the lymph follicle-like structure. There was neither T zone nor B zone in such structure, however, these cells were HLA-DR positive. Around the lymph follicle-like structure, both Leu M3 and HLA-DR positive cells with dendritic appearance were observed, whose immunohistochemical phenotype was similar to dendritic cell or interdigitating cell. The differentiation from lymphocytes to mature plasma cells was also observed in the submucosal connective tissue by the immunoelectronmicroscopical observation. These observations indicated that humoral immune system was activated in the middle ear of the patients with otitis media with effusion, and the possible pathogenical mechanisms of otitis media with effusion were discussed.