RESUMO
Usually, after double umbilical cord blood transplantation (DUCBT), only 1 of the transplanted units persists in the long term. The characteristics of the winning cord blood unit (W-CBU) that determine unit dominance and how they influence the outcomes of DUCBT remain unclear. We retrospectively analyzed 347 patients with acute leukemia transplanted with a DUCBT (694 CBU) from 2005 to 2013 who had documented neutrophil engraftment and a W-CBU identified by chimerism analysis, to identify unit characteristics impacting on dominance. Median age at DUCBT was 40 years and median follow-up was 35 months. Among W-CBUs, 41% were ≥5/6 HLA matched to the recipient and 59% were ≤4/6. Multivariate analysis indicated that ≤4/6 HLA-matched W-CBUs led to lower leukemia-free survival (44% versus 56%; hazard ratio [HR], 1.5; P = .032) and overall survival (49% versus 62%; HR, 1.5; P = .028), increased nonrelapse mortality (26% versus 18%; HR, 1.9; P = .027), and acute graft-versus-host disease (46% versus 35%; HR, 1.7; P = .013). We were unable to predict unit dominance, but we demonstrated that outcomes were strongly influenced by the degree of HLA mismatch between W-CBU and recipient. Therefore, selection of both units with the lower number of HLA mismatches with the recipient is indicated.
Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Leucemia/terapia , Doença Aguda , Adulto , Transplante de Células-Tronco de Sangue do Cordão Umbilical/mortalidade , Transplante de Células-Tronco de Sangue do Cordão Umbilical/normas , Feminino , Histocompatibilidade , Humanos , Leucemia/mortalidade , Masculino , Estudos Retrospectivos , Análise de Sobrevida , Quimeras de TransplanteRESUMO
Umbilical cord blood (UCB) from an human leucocyte antigen (HLA)-identical sibling can be used for transplantation of patients with malignant and non-malignant diseases. However, the low cellular content of most UCB units represents a limitation to this approach. An option to increase cell dose is to harvest bone marrow (BM) cells from the same donor and infuse them along with the UCB. We studied 156 children who received such a combined graft between 1992 and 2011. Median age was 7 years and 78% of patients (n = 122) were transplanted for non-malignant diseases, mainly haemoglobinopathies. Acute leukaemia (n = 26) was the most frequent malignant diagnosis. Most patients (91%) received myeloablative conditioning. Median donor age was 1·7 years, median infused nucleated cell dose was 24·4 × 10(7) /kg and median follow-up was 41 months. Sixty-days neutrophil recovery occurred in 96% of patients at a median of 17 d. The probabilities of grade-II-IV acute and chronic graft-versus-host disease (GVHD) were 19% and 10%, respectively. Four-year overall survival was 90% (68% malignant; 97% non-malignant diseases) with 3% probability of death. In conclusion, combined UCB and BM transplantation from an HLA-identical sibling donor is an effective treatment for children with malignant and non-malignant disorders with high overall survival and low incidence of GVHD.