PHENOTYPIC CHARACTERIZATION OF T-CELLS INFILTRATING THE CONJUNCTIVA IN CHRONIC ALLERGIC EYE DISEASE

Background: Chronic allergic conjunctivitis comprises a spectrum of di seases including atopic keratoconjunctivitis, atopic blepharoconjuncti vitis. Each condition is characterized by a complex immunopathology wi th a mixed cellular infiltrate. Treatment with conventional mast cell stabilizers is often unsatisfactory, and therapy depends heavily on to pical corticosteroids. Objective: Recent evidence suggests that T lymp hocytes play an important role in mediating the immunopathology seen i n the chronic allergic response in the skin and the lungs. Methods: We have therefore investigated the prevalence of T cells and their subse ts in the different chronic allergic conditions by means of immunohist ochemistry. Results: We found significantly increased numbers of CD4(), CD45RO, and HLA-DR(+) T cells in the conjunctiva of patients with a topic and vernal keratoconjuctivitis and giant papillary conjunctiviti s, with a corresponding upregulation of markers present on antigen pre senting cells. Conclusions: These findings suggest that like allergic conditions in the skin and lungs, CD4(+) memory T cells are involved i n the regulation of the immunopathology of chronic allergic eye respon ses. Further characterization of these T cells will provide the inform ation necessary for future immunotherapeutic interventions.