Haploidentical Natural Killer Cells to Treat Refractory or Relapsed Acute Myelogenous Leukemia (AML)

Inclusion Criteria: * ≥ 2 years of age * Meets one of the following disease criteria: * Primary acute myelogenous leukemia (AML) induction failure: no complete remission (CR) after 2 or more induction attempts * Relapsed acute myelogenous leukemia (AML): not in CR after 1 or more cycles of standard re-induction therapy. For patients \> 60 years of age the 1 cycle of standard chemotherapy is not required if either of the following criteria is met: * relapse within 6 months of last chemotherapy * blast count \< 30% within 10 days of starting protocol therapy * Secondary AML from myelodysplastic syndrome (MDS) * AML relapsed \> 2 months after transplant who do not have the option of donor lymphocyte infusions (e.g. recipients of autologous or umbilical cord blood \[UCB\] transplants) Patients with prior central nervous system (CNS) involvement are eligible provided that it has been treated and CSF is clear for at least 2 weeks or magnetic resonance imaging (MRI) stable prior to enrollment. CNS therapy (chemotherapy or radiation) should continue as medically indicated during the study treatment. * Available related HLA-haploidentical donor (3-5 of 6 HLA-A, B and C) * Karnofsky Performance Status \> 50% or Lansky Play score \> 50 * Adequate organ function defined as: * Creatinine: ≤ 2.0 mg/dL (for pediatric patients - ClCr \> 50 ml/min or age adjusted Cr) * Hepatic: Liver function tests (LFT's) \< 5 x upper limit of institutional normal (ULN) * Pulmonary Function: oxygen saturation ≥ 90% on room air and pulmonary function \>50% corrected Diffusion lung capacity for carbon monoxide (DLCO) and Forced expiratory volume in one second (FEV1) Oxygen saturation \[\>92%\] can be used in child where pulmonary function tests (PFT's) cannot be obtained. (Testing required only if symptomatic or prior known impairment.) * Cardiac Function: Ejection fraction (EF) ≥ 40%, no uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia or active conduction system abnormalities * Able to be off prednisone or other immunosuppressive medications for at least 3 days prior to natural killer (NK) cell infusion (excluding denileukin diftitox pre-meds) * Women of child bearing potential must have a negative pregnancy test within 14 days prior to study registration and agree to use adequate birth control during study treatment. * Voluntary written consent Exclusion Criteria: * Bi-phenotypic acute leukemia * Transplant \< 60 days prior to study enrollment * New or progressive pulmonary infiltrates on screening chest x-ray or chest computated tomography (CT) scan that has not been evaluated with bronchoscopy, if feasible. Infiltrates attributed to infection must be stable/improving (with associated clinical improvement) after 1 week of appropriate therapy (4 weeks for presumed or documented fungal infections). Surgical resection waives any waiting requirements. * Uncontrolled bacterial or viral infections - chronic asymptomatic viral hepatitis is allowed * Pleural effusion large enough to be detectable on chest x-ray * Known hypersensitivity to any of the study agents used * Received investigational drugs within the 14 days before enrollment * Known active CNS involvement