Extracorporeal photochemotherapy for graft versus host disease : Where we are now and where are we going !

Graft-versus-host disease (GVHD) remains the leading cause of morbidity, non-relapse mortality and treatment failure post allogeneic hematopoietic stem cell transplantation (allo-HSCT). So far, steroids are the 1st line treatment but around 40% of patients become steroid-resistant or fail to respond at a safe dose. Patients who fail to respond to the initial therapy have a dismal prognosis and no standard treatment is well established for them to date. Treatments that modulate the immune system rather than directly suppressing its function, although not dampening a potential graft-versus-malignancy effect, would therefore be highly desirable and extracorporeal photopheresis (ECP) appeared as being a good candidate to fill in these criteria. Multiple reports of treatments in both paediatric and adult patients with GVHD have been published, and the overall favourable profile compared with other available immunosuppressive therapies continues to make ECP appealing despite all of the unknowns. In this article, we review the use of extracorporeal photopheresis for the treatment of graft-versus-host disease including technical aspects, mechanism of action, safety profile and clinical efficacy data