Alloreactive NK Cells for Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

The goal of this clinical research study is to determine the safety and effects of giving a special kind of immune cells called "alloreactive natural killer (NK) cells" with high dose chemotherapy and allogeneic hematopoeitic stem cell transplantation with the goal of defining the maximum tolerated dose of NK cells. The NK cells will be donated from a relative of yours who has certain genetic type in their blood called HLA, that almost matches yours. The stem cells you will receive will come from a separate HLA matched (HLA A, B, C, DR) relative or unrelated donor. The safety of this treatment will also be studied.