Objective       To evaluate the curative efficacy of single-unit umbilical cord blood transplantation (sUCBT) without antithymocyte globulin (ATG) for acute leukemia with central nervous system leukemia (CNSL) involvement.       Methods      Retrospective analys

is was performed on clinical data of 15 acute leukemia undergoing sUCBT between Jul. 2009 and Sep. 2014 in our department. There were 2 cases of acute mononuclear leukemia

1 case of acute myelocytic leukemia (M1)

and 12 cases of acute lymphoblastic leukemia. All patients achieved complete remission in CNSL before transplantation. All cases received intensified myeloablative conditioning regimen

with 9 cases of total body irradiation(TBI)/cytosine arabinoside (Ara-C)/cyclophosphamide(CY)

3 cases of Ara-C/Busulfan (Bu)/CY and 3 cases of Flu/Bu/CY

using a combination of CsA and MMF for the prophylaxis of graft-versus-host disease (GVHD).       Results      Fourteen patients were engrafted with neutrophils that exceeded 0.5×10

9

/L in median 19 (13～27) d

and had platelet counts ≥20×109/L in median 41 (20～85) d. Twelve patients developed pre-engraftment syndrome (PES). Among the 14 evaluated cases

3 patients appeared acute GVHD

with the cumulative incidences of Ⅱ～Ⅳ and Ⅲ～Ⅳ aGVHD of 20.00% and 13.33% respectively. There was no extensive chronic GVHD occurred except for 3 cases with skin chronic GVHD in limited type

with a cumulative incidence of 720-day cGVHD of 20.00%. During the median follow-up of 43.2(14.1～76.5) months

there were 4 patients died

consisting of 1 case with multiple organ failure before engraftment

1 case with severe aGVHD and 2 cases with disease recurrence. Three patients relapsed after transplantation

in which 2 cases of bone marrow relapse.There was only 1 case of central nervous system relapse

and achieved complete remission after intrathecal injection and cranial radiation.The probability of 3-year overall survival rate and disease-free survival rate were 60.0% and 53.3% respectively.       Conclusion       The preliminary investigation of sUCBT with intensified myeloablative conditioning regimen without use of ATG has showed good curative effect for acute leukemia with central nervous system involvement

worthwhile further popularization and application.