 This protocol aims to measure the safety and effectiveness of extracorporeal photopheresis ECP therapy for maintaining remission of symptoms during withdrawal of corticosteroids from patients with steroid-dependent Crohns disease. Potential subjects will be asymptomatic or have a low level of symptoms that respond to an increase in their steroid dose; furthermore potential subjects will be dependent on steroids to control their symptoms and have a history of failing other immunosuppressive drugs to control their symptoms. 