Cell populations in pagetoid reticulosis: an immunological study using cell activation associated monoclonal antibodies.

The nature of the epidermal cellular infiltrate in pagetoid reticulosis is still subject to intense controversies. Using a panel of recently developed monoclonal antibodies against cell activation and proliferation associated antigens it was possible to demonstrate the activated state of numerous T cells within the lesional epidermis. Moreover approximately 10% of these T cells reacted with proliferation associated antigens. In addition macrophages and Langerhans' cells were found to represent a regular constituent of the epidermal infiltrate with a density clearly exceeding that of unaffected adjacent epidermis. The close apposition of activated T cells and monocytic cells suggests an intensive interaction of both cell types in the development of the pagetoid reticulosis lesion.