Photopheresis. Therapeutic potential in preventing restenosis after percutaneous transluminal coronary angioplasty.

Photopheresis (extracorporeal photochemotherapy) is an immunomodulatory therapy that entails the reinfusion of peripheral blood mononuclear cells after exposure to the photoreactive agent methoxsalen and ultraviolet A (UVA) radiation. Currently available at approximately 150 treatment centers worldwide, photopheresis is approved by the US FDA for advanced-stage cutaneous T-cell lymphoma (CTCL) and has also shown promise in treating nonmalignant immune-related conditions such as organ transplant rejection, acute and chronic graft-versus-host disease, and autoimmune disorders. The precise mechanism by which photopheresis evokes clinical responses is unknown, although this modality seems capable of modulating T-cell and monocyte activity.