Donor Lymphocyte Infusion Post-Transplant

The purpose of this study is to reduce the risk of cancer relapse by giving a donor lymphocyte infusion (DLI) to boost the immune system early after a stem cell transplant so that leukemia cells that escaped chemotherapy can be detected and killed. This DLI will contain mostly lymphocytes that have graft versus tumor effect with low risk of graft versus host disease. Because the process of giving a DLI in the first four weeks after a transplant has not been approved by the Food and Drug Administration (FDA), this study in investigational (experimental).