Langerhans' cells in chronic otitis media.

Langerhans cells (LCs) were studied in chronic otitis media (COM) by the immunoperoxidase technique and monoclonal antibodies. The LCs were a regular finding in both thin and thick cholesteatoma epithelium, and in open cavity skin. OKT-6 positive cells were also found in smaller numbers in subepithelial connective tissue and lymphoid follicles, and in cuboidal secretory epithelium. LCs form an important part of the immune defence system of the skin, which lacks the humoral secretory IgA defence mechanism of the mucous membranes. There is no proof that LCs are connected with the keratinization process and possible reformation of cholesteatoma.