Extracorporeal photochemotherapy in the treatment of severe graft-versus-host disease.

Advances in posttransplant immunosuppression have to the present not been able to prevent the development of graft-versus-host disease (GVHD) in patients given related or unrelated stem cell grafts for cure of hematologic diseases. Patients with GVHD not responding to first line therapy with corticosteroids remain at high risk of death due to severe infections or organ failure. Extracorporeal exposure of peripheral blood mononuclear cells to the photosensitizing agent 8-methoxypsoralen and ultraviolet A radiation has been shown to be effective in treatment of selected T-cell mediated diseases, including cutaneous T-cell lymphoma and rejection after organ transplantation. Extracorporeal photochemotherapy (ECP) is also a safe and efficacious adjunct therapy for both acute and chronic extensive GVHD with skin and visceral involvement and resistance to conventional immunosuppressive therapy. A multicenter randomized study should help define the impact of ECP in the treatment of GVHD and overall survival of these patients.