Photopheresis: Advances and Use in Systemic Sclerosis

Extracorporeal photochemotherapy (photopheresis, ECP) is a cell-based immunomodulatory treatment that separates leukocytes from peripheral blood, exposes them to a photosensitizing agent followed by ultraviolet A light, and then reinfuses them back into the patient. ECP has been found to be effective for graft versus host disease, transplant rejection, and various autoimmune diseases. The mechanism is not well understood but studies have shown clinical benefit in the treatment of systemic sclerosis (SSc). This review examines the ECP technique, advances in our knowledge of its mechanism, and the data supporting its use in SSc-like fibrosing diseases and in SSc itself.

Multiple lines of evidence support ECP use in SSc. ECP generates apoptotic cells and dendritic cells, induces production of anti-inflammatory cytokines, and increases regulatory T cell numbers. Clinical studies have generally demonstrated improvement, especially the skin, in SSc patients receiving ECP. ECP may be an effective and safe procedure for the treatment of SSc.