Mechanism of action of extracorporeal photochemotherapy in chronic graft-versus-host disease.
Chronic graft-versus-host disease (GvHD) affects 50% of long-term bone marrow transplant survivors and remains a cause of major long-term morbidity in these patients despite aggressive therapy. Extracorporeal photochemotherapy (ECP), considered as an effective treatment for patients with erythrodermic cutaneous T-cell lymphoma (CTCL), has recently been used successfully in the treatment of GvHD. One of the most intriguing aspects of ECP is its ability to induce two apparently opposite effects: activation of the immune system against neoplastic cells (as in CTCL) and downregulation of the activity of T-cell clones in autoimmune diseases (as in systemic sclerosis, systemic lupus erythematosus and pemphigus vulgaris) and autoallogeneic immune responses (as in GvHD and allograft rejection). Only a better and more complete understanding of the various mechanisms involved will enable this interesting new therapy to be made more effective and selective.
Fimiani
M
M
Istituto di Scienze Dermatologiche, Università degli Studi di Siena, Policlinico Le Scotte, 53100 Siena, Italy. fimiani@unisi.it
Di Renzo
M
M
Rubegni
P
P
D017209:Apoptosis; D016026:Bone Marrow Transplantation; D002908:Chronic Disease; D003713:Dendritic Cells / Q000276:immunology; D006086:Graft vs Host Disease / Q000276:immunology / Q000628:therapy*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology / Q000628:therapy; D009000:Monocytes / Q000473:pathology / Q000528:radiation effects; D017893:Photopheresis; D014181:Transplantation Immunology