Inflammatory cell subpopulations in chronic otitis media. The Langerhans' cells.

Langerhans' cells (LCs) were studied in chronic otitis media by the immunoperoxidase technique and monoclonal antibodies. The LCs were a regular finding in ear canal skin, Shrapnell's membrane, thin and thick cholesteatoma epithelium, and open cavity skin; OKT6-positive cells were also found in smaller numbers in subepithelial connective tissue and lymphoid follicles, and in cuboidal secretory epithelium. The HLA-DR antibodies are less suitable for identification of LCs because many lymphoid cells express this antigen. Langerhans' cells form an important part of the immune defense system of the skin, which lacks the humoral secretory IgA defense mechanism of the mucous membranes. There is no proof that LCs are connected with the keratinization process and the possible reformation of cholesteatoma.