Photopheresis

This information is useful for children, adults, and older adults
Blood traveling through tubes, illustrating the process of photopheresis

Credit: Robert A. Lisak

Photopheresis (also known as extracorporeal photochemotherapy, ECP) is a blood-filtering treatment that works with your body’s own immune system to treat disease. This immunotherapy was developed by a Yale Medicine dermatologist to treat cutaneous T-cell lymphomas, a rare group of cancers that usually affects the skin but sometimes can be found in the blood, lymph nodes and other internal organs.

Over time, the treatment has been used for other health issues like graft-versus-host disease (GVHD, in which donated bone marrow or blood stem cells attack the recipient’s body) and organ rejection. Today, Photopheresis is being investigated as a potential treatment for other autoimmune diseases.

What’s unique about Photopheresis is how it can be tailored to particular needs. Sometimes it is used as a kick-start, to strengthen an immune response, while in other situations it provides what amounts to a “reset,” halting a problematic immune response.

“People are surprised that you can have one therapy capable of turning on the immune system when you need a stronger reaction, like with cancer. Or turning it off, when the immune system is actually causing the problem, like with a reactive organ transplantation rejection,” says chief of Yale Medicine Dermatology Richard Edelson, MD, who developed the treatment in 1987.

At Yale Medicine Dermatology’s ECP (Photopheresis) Immunotherapy Program, our dermatology team treats patients with cutaneous T-cell lymphoma, GVHD and organ transplant rejection. Our physician-scientists are actively studying how Photopheresis may be used to treat a host of other immunologic disorders. 

Photopheresis is considered a cellular immunotherapy that recruits the body’s “fighter” white blood cells (T-cells) to wage (or calm) an immune response, as needed.

The treatment is performed on a patient's blood. Using either an IV or a catheter, blood is routed through a device which separates a portion of white blood cells (leukocytes) and treats them with naturally occurring photosensitizing chemicals called 8-methoxypsoralen (8-MOP), also called psoralen. (Psoralen is found in lemons, figs and celery, for instance.) Once chemically treated, the blood is then exposed to specific wavelengths of ultraviolet (UVA) light. The blood—with its immune cells either activated by the treatment to fight off cancer or slowed down to prevent organ rejection— is then returned to the patient’s body. Though somewhat time-consuming (it takes three to four hours, performed over a couple days, and repeated every few weeks for at least several months), the treatment is not painful and causes relatively few, if any, side effects.