Prophylactic Infusion of Donor Lymphocytes in Cord Blood Transplantation

Inclusion Criteria: At the time of transplantation: * Patients under 60 years with proposal UCBT according to assistance protocol * Diagnosis of high-risk acute leukemia with an indication of allogenic transplantation * Frozen UCB bag split into two bags: one with the 80% of the product and another with the 20% * Presence of at least 1.2E9 total nucleated cells and\> 1E5 CD34 / kg and\> 6E6 CD34 + in fraction 80% * 4/6 or better compatibility taking Human Leukocyte Antigen (HLA) HLA-A, HLA-B by antigenic resolution and DRB1 by allelic resolution * The patient (or legal representative if required) has signed the informed consent At the time of DLI: * Documented cord blood engraftment * The patient has had no Graft Versus Host Disease (GVHD) during the first 60 days post-transplantation or, if present, receives less than 10 milligrams of prednisone at the time of the DLI or \<0.2 mg / kg / day of prednisone for pediatric patients (\<16 years). * The patient has less than 200 CD4 + cells per microliter on peripheral blood at 60 days (± 7 days) post-transplantation * The patient (or legal representative if required) has signed the informed consent Exclusion Criteria: At the time of transplantation: * Simultaneous participation in another clinical trial or treatment with other research phase product within 30 days prior to inclusion in the study. * Pregnant women or those who intend to become pregnant within 12 months after the signing of the informed consent or not taking proper contraceptive measures according to investigator criteria. * Breastfeeding women * Other pathologies or circumstances that may compromise the patient's participation in the study according to the criteria of the investigator. At the time of DLI: * Grade III-IV GVHD after allogeneic UCB * Prednisone treatment (\> 10 mg total per day in adults or\> 0.2 mg / kg / day prednisone for pediatric patients)