EXTRACORPOREAL PHOTOCHEMOTHERAPY - A SCIENTIFIC OVERVIEW

Extracorporeal photochemotherapy was developed for treatment of cutane ous T-cell lymphoma (CTCL). Several independent and multicenter trials using lymphapheresis with 8-methoxypsoralen (8-MOP) activated by shor twave ultraviolet light have demonstrated the clinical benefit of this modality for treatment of advanced CTCL. Recently, trials using the c ombination of photochemotherapy and recombinant interferons or photoch emotherapy and low doses of methotrexate have been initiated to enhanc e the response to photopheresis. Also, a multicenter study evaluating a new 8-MOP formulation that could be added into the leukocyte/plasma fractions prior to ultraviolet exposure is in progress in CTCL patient s. The applications of photochemotherapy in the treatment of other dis orders of T-cells are being examined in ongoing clinical trials. Pilot studies have been completed and controlled trials are under way in pa tients with autoimmune diseases. Important information has emerged reg arding the potential use of photopheresis for prevention of solid orga n allograft rejection. Several investigators have undertaken pilot stu dies comparing the efficacy of photochemotherapy with the conventional immunosuppressive therapy for treatment of cardiac transplant rejecti on. It is hoped that photochemotherapy can induce an immune tolerance in the allograft setting and therefore eliminate or reduce the use of cyclosporin. Other considerations have led to the use of photochemothe rapy in the prevention and treatment of graft-versus-host disease afte r alloeneic and unrelated donor marrow transplantation. Randomized stu dies are required to evaluate the impact of photochemotherapy on the c ourse of graft-versus-host disease and overall survival.