[Extracorporeal photochemotherapy: review of its mechanisms of action and clinical applications]. / La photochimiothérapie extracorporelle: revue de son mode d'action et de ses indications.

Extracorporeal photochemotherapy is an immunomodulatory treatment wich is carried out in three steps: first leukapheresis, then ex vivo PUVA treatment and finally autologous transfusion. Its current "evidence-based" indications are erythrodermic cutaneous lymphoma, graft versus host disease and cardiac graft rejection. However this treatment has already been used with success in many other diseases such as systemic sclerosis, multiple sclerosis, type 1 diabetes and various autoimmune dermatologic diseases. Randomised controlled studies are needed to confirm the efficacy of photopheresis in these diseases. We also review the different hypotheses explaining the mechanism of action of photopheresis.