Mast cell hyperplasia in atopic keratoconjunctivitis. An immunohistochemical study.

Immunohistochemical staining of conjunctival biopsies from four normal subjects and five patients with atopic keratoconjunctivitis (AKC) was performed, using a monoclonal antibody to human mast cell tryptase. A massive hyperplasia of mast cells in the patients with AKC was demonstrated. The mean mast cell density in the normal patients was 55.6/mm2 and in the patients with AKC, 172/mm2. The appearance of large numbers of mast cells in the conjunctival epithelium of AKC patients was also demonstrated. The possible pathophysiological significance of these findings is discussed.