The role of extracorporeal photopheresis in chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) is the most important cause of late morbidity and mortality in recipients of allogeneic blood and marrow transplantation. Despite increased understanding of biology of chronic GVHD, treatment options remain limited and ineffective. While corticosteroids represent the backbone of initial chronic GVHD treatment, they have significant long-term toxicity and more than half of the patients require second-line therapy. Among the second-line treatments for chronic GVHD, extracorporeal photopheresis (ECP) is one of the most extensively studied modalities. While high quality studies establishing true value of ECP in chronic GVHD patients are lacking, its benefits in chronic GVHD are well documented. Its putative immunomodulatory, but not immunosuppressive, properties represent an attractive alternative to the other strategies leading to global immunosuppression and the resulting risks of opportunistic infections or malignancy relapse.