Class II antigen expression of epidermal Langerhans cells in renal allograft recipients

This study was designed to investigate the influence of systemic immunosuppressive therapy on the HLA-DR expression of epidermal Langerhans cells. Fifteen renal allograft recipients immunosuppressed with cyclosporin A and steroids were studied. Skin biopsies were taken from the upper arm prior to transplantation and at different intervals during the post-transplantation period. The epidermis was separated from the dermis, and the epidermal sheet was subjected to immunohistochemistry in order to make the HLA-DR antigens on the Langerhans cells visible. Following 2 days of immunosuppression, the number of Langerhans cells expressing HLA-DR antigens started to decrease and after 1 week, only 60% of the initial number of positive cells were detected. The number of positive cells remained low throughout the experimental period. It is suggested that systemic immunosuppressive therapy will suppress the expression of HLA-DR antigens on epidermal Langerhans cells, something which may mirror a systemic effect on other antigen-presenting cells.