Extracorporeal Photopheresis: Scientific and Technical Considerations for Improving Clinical Management of Patients

Starting at the end of 90’s, and derived from PUVA therapy, arose the concept of modulation of inappropriate immune conflicts by direct action of UVA on immunocompetent cells (lymphocytes, antigen processing cells). After the inactivation of T-cells in vitro and ex vivo, was demonstrated, the development step-by-step aimed to process large amounts of the so-called peripheral mononuclear cells. Harvested by apheresis followed by psoralen and UVA treatment cells are reinjected into the patient. The process is called extracorporeal photopheresis or chemophototherapy (ECP). First systemic indications were Sezary syndrome [1], graft versus host disease (GVHD) and solid organ transplantation [2,3]. Today, ECP clinical relevance is demonstrated for three major indications: chronic GVHD, Sezary T-cell lymphoma and cardiac graft rejection.