Photopheresis in the treatment of cutaneous T-cell lymphoma: current status.

Cutaneous T-cell lymphoma is the overall name for a group of malignancies in which malignant T-lymphocytes localize at the skin. Of the current 20 recognized subtypes of the disease, the most common are mycosis fungoides and Sézary syndrome. Extracorporeal photopheresis (ECP), an immunomodulating procedure that treats pheresed blood with a photoactive agent, received US Food and Drug Administration approval in 1988 as a medical device for the treatment of CTCL patients, one of many treatment options for such patients. This was followed in 2003 by guidelines in the United Kingdom that recommended ECP for patients with advanced CTCL, particularly after skin-directed treatment options have failed. ECP is now under investigation for use in patients with earlier stages of CTCL. This article reviews the evolution of the ECP technique--for example, the most recent generation of the device requires a lower extracorporeal volume of blood than the previous version did, thus making it possible for more patients to be candidates for the procedure. In addition, there has been progress in understanding how ECP works at the cellular level.