Conjunctival inflammation in the chronic phase of Stevens–Johnson syndrome

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.