Background: Vernal keratoconjunctivitis (VKC) often is associated with atopy but a considerable part of the patients lack evidence of specific hypersensitivity. An immunocytochemical study was undertaken with the aim of detecting possible differences in the tissue inflammatory response between atopic and nonatopic subjects with VKC.
Methods: Conjunctival biopsy specimens from six atopic and three nonatopic subjects with VKC (age range, 7-17 years) and eight healthy control subjects (age range, 3-15 years) were analyzed with a panel of monoclonal and polyclonal antibodies.
Results: No distinct differences in cell counts between atopic and nonatopic subjects with VKC were observed. Vernal keratoconjunctivitis specimens as a whole showed higher counts than control specimens for CD3+, CD4+, HLA-DR+, CD38+, EG2+, CD68+, IgE+, FC epsilon RI+, IgA+, IgG+, and IgM+ cells in the substantia propria; and for CD1a+, IgE+, and EG2+ cells in the epithelium.
Conclusions: Because the number of cells expressing CD4, EG2, IgE, and the high-affinity receptor for IgE, all of which are considered relevant in infiltrates of allergic conditions, were similar in atopic and nonatopic subjects, the authors conclude that the role of allergen-specific IgE sensitization in the pathogenesis of VKC remains unclear.