title: Long-term outcomes in adults with leukemia treated with transplantation of two unrelated umbilical cord blood units.
abstract: BACKGROUND
  Wide application of umbilical cord blood transplantation (UCBT) in adult patients is limited by low cell-dose available in one umbilical cord blood (UCB) unit. The aim of this study was to investigate the safety and long-term outcomes of UCBT from unrelated donors in adult and adolescent patients with leukemia.
  
  
  METHODS
  Thirteen patients with leukemia received double-unit UCBT with human leukocyte antigen (HLA) mismatched at 0 - 2 loci. We analyzed the engraftment, graft-versus-host disease (GVHD) and survival.
  
  
  RESULTS
  Twelve evaluable patients (92.3%) had neutrophil and platelet engraftment at a median of 21 days (range, 16-38 days) and 34 days (range, 25 - 51 days), respectively. At day 30, engraftment was derived from one donor in 8 patients (66.7%, 95%CI 40.0% - 93.4%), and from both donors in 4 patients (33.3%, 95%CI 6.7% - 60.0%) with 1 unit predominated. Unit with larger nucleated cell (NC) dose would predominate in engraftment (P = 0.039), whereas CD34(+) cell dose or HLA-match failed to demonstrate any relationship with unit predominance. Only one patient developed grade II acute graft-versus-host disease (aGVHD). Chronic GVHD (cGVHD) was observed in 2 of 11 patients who survived more than 100 days, and both were limited. The median follow-up after transplantation for the 13 patients was 45 months (range 1.5 - 121.0 months) and 72 months (range 41.0 - 121.0 months) for the 8 alive and with full donor chimerism. The 5-year cumulative disease free survival (DFS) was (61.5 ± 13.5)%. Of the 13 patients, 5 patients died in 1 year and 1-year transplantation related mortality (TRM) was 23.1% (95%CI 0.2% - 46.0%).
  
  
  CONCLUSIONS
  Double-unit UCBT from unrelated donors with HLA-mismatched at 0-2 loci may overcome the cell-dose barrier and be feasible for adults and adolescents with leukemia.
authors.affiliation: Department of Hematology, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Yin
authors.forename: Han-Yun
authors.initials: HY
authors.lastname: Ren
authors.forename: Xin-An
authors.initials: XA
authors.lastname: Cen
authors.forename: Zhi-Xiang
authors.initials: ZX
authors.lastname: Qiu
authors.forename: Jin-Ping
authors.initials: JP
authors.lastname: Ou
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Wang
authors.forename: Mang-Ju
authors.initials: MJ
authors.lastname: Wang
authors.forename: Wei-Lin
authors.initials: WL
authors.lastname: Xu
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Dong
mesh_terms: D000293:Adolescent; D000328:Adult; D036101:Cord Blood Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006086:Graft vs Host Disease / Q000209:etiology; D006801:Humans; D007938:Leukemia / Q000276:immunology / Q000401:mortality / Q000628:therapy*; D008297:Male; D016896:Treatment Outcome; D055815:Young Adult