Immunohistochemical identification of inflammatory cells in secretory and chronic otitis media and cholesteatoma using monoclonal antibodies.

Monoclonal antibodies (OKT 3,4,6,8 and OKIa) were used in conjunction with the avidin-biotin-peroxidase complex method to classify inflammatory cells in 6 biopsies of the middle ear mucosa in patients with secretory otitis media (SOM) and in 19 middle ear or mastoidal biopsies in patients with chronic otitis media (COM). Mononuclear cell infiltrates under the mucosal epithelium were found to consist mainly of T4 positive (helper-inducer) T-lymphocytes (50-60%). T8 positive (suppressor-cytotoxic) T-lymphocytes accounted for 20-30% of the cells. T4 positive cells were confined to the round cell infiltrates, whereas T8 positive cells were also located under the mucosal epithelium and seemed to penetrate it. There were no differences between SOM or COM with regard to the distribution or localization of T4 and T8 cells. T6 and Ia positive Langerhans cells were found in the ingrowing tympanic membrane squamous epithelium and in the cavity skin. The number and distribution of these T6 positive cells were similar to those observed in the skin. In the thick cholesteatoma epithelium these cells were somewhat unevenly distributed but were more numerous than in other sites studied. The results are indicative of a normal cell-mediated mucosal response to infection.