AIMS—To understand the immunopathogenesis of the corneal conjunctivalisation in Stevens-Johnson syndrome. METHODS—Conjunctivalised corneas from five patients with Stevens-Johnson syndrome were studied immunohistochemically for several cell surface antigens and two cytokines. Chemical injury specimens were also studied. RESULTS—In all cases, immunohistochemistry revealed LFA-1, CD4, CD8, and CD68 on subepithelial infiltrating cells. Also, HLA-DR and ICAM-1 were found on the surfaces of epithelial cells, subepithelial infiltrating cells, subepithelial fibroblasts, and endothelial cells in blood vessels. IFN-γ was found in basal epithelial cells; subepithelial cells and subepithelial extracellular matrix CD19 and IL4 were not detected. CONCLUSIONS—The infiltrating cell population in the Stevens-Johnson syndrome samples includes macrophages, CD4 positive T cells, and CD8 positive T cells. The cytokine expression pattern suggests CD4 positive T cells are Th1 cells. The infiltrating cell population is similar in Stevens-Johnson syndrome and chemical injury conjunctivalised corneas.
