Biomarkers in Predicting Response in Patients With Graft-Versus-Host Disease Undergoing Extracorporeal Photophoresis

PRIMARY OBJECTIVE: I. To show that extracorporeal photopheresis (ECP)increases skin and gut homing T regulatory (T-reg) cells in patients with GVHD clinically responding to ECP. SECONDARY OBJECTIVES: I. Response rates of GVHD with extracorporeal photopheresis(ECP)as measured by NIH response criteria II. Incidence of T-reg cell frequency(%)with various NIH subtypes of chronic graft-versus-host disease (GVHD) III. Incidence of T-reg homing subsets(%)with various NIH subtypes of chronic graft-versus-host disease (GVHD) OUTLINE: Patients undergo ECP twice a week for 4 weeks and then twice a week every 2 weeks for 8 weeks. After completion of study treatment, patients are followed up at 2, 4, and 6 months.