As the understanding of the pathophysiological mechanisms underlying RA is elucidated, the opportunity to target specific inflammatory processes with new therapies has improved. Rheumatoid arthritis is a T cell-mediated autoimmune disease and there are various therapies, including newer experimental therapies, which target either the activation of T cells or the neutralization of their effector mechanisms. These newer therapies have shown benefit in human and animal models of RA. Extracorporeal photoimmune therapy (ECP) has been shown to be safe and effective in the palliative treatment of the skin manifestations of cutaneous T cell lymphoma. Experimental studies have also demonstrated activity of ECP treatment in several T cell mediated diseases including graft versus-host disease, rejection after organ transplantation, and selected autoimmune diseases.