ANALYSIS OF THE ALPHA BETA-T-CELL AND GAM MA/DELTA-T-CELL RECEPTORS PRESENT IN THE CONJUNCTIVAL TISSUE OF PATIENTS OCULAR CICATRICIAL PEMPHIGOID/

Background: In the conjunctiva of asymptomatic persons and patients wi th ocular cicatricial pemphigoid the existence and distribution of alp ha/beta- and gamma/delta-T cell receptor (TCR)-positive cells has not previously been investigated. Patients and methods: Biopsy specimens f rom 20 patients with clinically diagnosed ocular cicatricial pemphigoi d (OCP) were compared with 20 specimens from asymptomatic persons. add itionally, 3 specimens from patients with OCP treated with cytotoxic d rugs and 8 specimens from patients who had undergone mucosal transplan tation were studied. antigen retrieval was done in deparaffinized spec imens for immunohistochemical identification of alpha/beta- and gamma/ delta-TCR-positive cells by monoclonal antibodies and an appropriate d efection system. all steps were performed in triplicate, and negative control sera were applied. Results: alpha/beta-TCR-positive cells were observed in the conjunctival epithelium and stroma of all the asympto matic persons and in all patients with OCP. gamma/delta-TCR-positive c ells were found in 4 out of 20 patients with OCP in epithelial sites, but not in asymptomatic persons. Patients with OCP who had received cy totoxic treatment exhibited neither alpha/beta- nor gamma/delta-TCR-po sitive cells. Staining sites of alpha/beta-TCR-positive cells changed from membrane-bound to nuclear in patients who had undergone mucosal t ransplantation, and were cytoplasmic rather than membrane-bound in gam ma/delta-TCR positive cells. Conclusions: This study presents prelimin ary evidence for the existence of distinct T-cell subsets in the conju nctiva of healthy persons and of patients with OCP. Further functional studies in fresh tissue material may provide better insights into the role of defined T-cell subsets in the immunopathogenesis of autoimmun e diseases of the outer eye such as OCP.