Long-Term Outcome of Preemptive Immunotherapy Based on Post-Transplant Chimerism and MRD Monitoring after Allogeneic Stem Cell Transplantation in Children with Acute Lymphoblastic Leukemia: A Single Center Experience

Abstract Introduction: Mixed chimerism (MC) and minimal residual disease (MRD) strongly predict risk for relapse in children with acute lymphoblastic leukemia (ALL) following allogeneic stem cell transplantation (allo-SCT). Preemptive immunotherapy (IT), e.g. withdrawal of immunosuppression (WD-IS) or donor lymphocyte infusion (DLI) guided by chimerism and MRD monitoring can prevent impending relapse in allo-SCT recipients. In this study we retrospectively analyzed chimerism and MRD monitoring and the effect of preemptive IT in all pts undergoing allo-SCT for ALL in our institution. Patients: Between January 2005 and July 2014, a total of 89 children and adolescents (median age 11.5; range …