An immunohistochemical study of topical cyclosporine in vernal keratoconjunctivitis

PURPOSE: To determine the immunomodulating effects of topical cyclosporine on the immune cells in the conjunctival biopsy specimens obtained from patients with active vernal keratoconjunctivitis. METHODS: We studied six patients who had severe active vernal keratoconjunctivitis. Each patient was given topical cyclosporine 2% eyedrops four times daily, A 2 x 2-mm limbal conjunctival biopsy specimen was obtained from each patient before and three weeks after treatment, Using a panel of monoclonal and polyclonal antibodies and immunohistochemical techniques, we analyzed the conjunctival immune cells before and after cyclosporine treatment. RESULTS: Three weeks after topical cyclosporine treatment, there was marked clinical improvement and a statistically significant reduction in the number of epithelial and stromal class II MHC(+) cells, UCHL(1)(+) T cells, and stromal IgA(+) and IgG(+) plasma cells, The mean number of cells before and after therapy, respectively, were: class II MHC(+) (epithelium), 31.5 +/- 13.1 and 8.3 +/- 5.6 (P = .031); class II MHC(+) (stroma), 77.0 +/- 28.7 and 24.7 +/- 17.5 (P = .031); UCHL(1)(+) T cells (epithelium), 24.5 +/- 14.1 and 4.2 +/- 2.9 (P = .031); UCHL(1)(+) T cells (stroma), 78.7 +/- 31.1 and 44.5 +/- 27.5 (P = .031); IgA(+) plasma cells, 66.7 +/- 32.1 and 22.2 +/- 7.8 (P = .031); and IgG(+) plasma cells, 37.3 +/- 30.0 and 9.0 +/- 6.4 (P = .031), There was a statistically insignificant decrease in the epithelial class II MHC(+) dendritic Langerhans cells, epithelial and stromal KP1+ macrophages, stromal OPD4+ helper/inducer T cells, and stromal L26(+) B cells, The numbers of IgE(+) plasma cells and mast cells were unaltered. CONCLUSION: The clinical improvement in vernal keratoconjunctivitis after topical cyclosporine therapy may result from its immunomodulating effect on the components of cell-mediated and humoral immune responses, In contrast, the drug has no immunomodulatory effect on mast cells and IgE-mediated allergic response.