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Background: Although the use of cord blood transplantation (CBT) is becoming more frequent in acute leukemia, considering the relationship between the low stem cell dose and graft failure, whether use of CBT for adolescents and young adults (AYAs) is appropriate remains uncertain. Methods: A retrospective registry-based analysis of clinical outcomes and immune reconstitution was conducted for 105 AYAs and 187 children with acute leukemia who underwent single-unit CBT using myeloablative conditioning (MAC) without antithymocyte globulin (ATG). Results: Outcomes were similar between AYAs and children, except for nonrelapse mortality (NRM) and recovery rates of neutrophils and platelets. The 30-day cumulative incidence of neutrophil engraftment was similar between AYAs and children, but children had faster rates of neutrophil and platelet recovery than AYAs. The median time to neutrophil engraftment was earlier in children than in AYAs (AYAs, 19 days, 95% confidence interval [CI] 17.3–21.7; children, 16 days, 95% CI 13.1–19.5, p = 0.00003). The incidence of platelet recovery on day 120 was higher in children than in AYAs (AYAs, 80%, 95% CI 71–81%; children, 88%, 95% CI 82–92%, p = 0.037). CD34+ cell dose was the only independent factor influencing both neutrophil and platelet recovery. The cumulative incidence of NRM at 2 years was higher among AYAs than among children (AYAs, 27.5%, 95% CI 20–37%; children, 15%, 95% CI 10–21%, p = 0.008). Conditioning regimen was an independent factor influencing NRM. With respect to immune reconstitution, natural killer cell counts quickly recovered to normal levels 1-month post-CBT in both children and AYAs. CD8+ T-cell counts were higher in children than in AYAs at 1 and 3 months post-CBT. CD4+ T-cell counts were similar in both children and AYAs after CBT. Conclusion: AYAs with acute leukemia have outcomes of single-unit CBT using MAC without ATG that are as good as those of children. Thus, single-unit CBT using modified MAC without ATG is an acceptable choice for both AYAs and children who do not have a suitable donor. [ABSTRACT FROM AUTHOR]

No clinical studies have investigated the role of decitabine as a part of the myeloablative conditioning regimen prior to UCBT for refractory or relapsed childhood AL in patients in NR status. The aim of this study was to identify the potential benefits of decitabine as a prior therapy before salvaged unrelated UCBT for refractory or relapsed childhood AL. Eight consecutive patients with childhood refractory/relapsed AL were enrolled in our study between 2013 and 2014. All patients were in NR status before the time of transplant and had features associated with poor outcomes, such as CNSL, MDS- AML, high WBC count at diagnosis, and hypodiploid status ( FLT3+/ ITD+). Additionally, all patients had one of the following disease statuses: PIF, multiple relapse, or early relapse. All transplants were performed with decitabine as part of the myeloablative conditioning regimen, which was decitabine+Flu/Bu/ CY± BCNU or decitabine+Ara-c/ BU/ CY2± BCNU. A total of seven patients (7 of 8) achieved neutrophil engraftment and platelet engraftment, and one patient experienced primary graft failure. All eight patients (100%) developed PES at a median of 7 days. Three patients developed stage II- IV acute GVHD at a median of 18 days. Additionally, three patients developed chronic GVHD, but it was not extensive in any of those three patients. The median follow-up time after CBT was 19.9 months (range, 9.2-30.7 months). The estimated probability of OS was 75%. Two patients (2 of 8) experienced a testis relapse, and two patients (2 of 8) died. Our experience suggests that the additional application of decitabine as part of the myeloablative conditioning regimen prior to UCBT for refractory or relapsed childhood AL among patients who are not in remission is safe and might be an effective treatment option. [ABSTRACT FROM AUTHOR]

The European Group for Blood and Marrow Transplantation (EBMT) risk score has been implemented as an important tool to predict patient outcomes after allogeneic hematopoietic stem cell transplantation. However, to our knowledge, this score has never been applied in cases of single umbilical cord blood transplantation (sUCBT). We retrospectively analyzed 207 consecutive patients with acute leukemia who received sUCBT at our center between February 2011 and December 2015. The probabilities of 3-year overall survival (OS) and leukemia-free survival (LFS) of the entire cohort were 65.0% and 59.8%, respectively, whereas the cumulative incidences of 3-year nonrelapse mortality (NRM) and relapse rate were 19.5% and 20.3%, respectively. In the univariate analysis, a higher EBMT risk score was associated with worse OS and LFS and higher NRM and relapse rate, ranging from 81.7%, 75.9%, 7.3%, and 15.3%, respectively, for patients with a score of 1 to 43.8%, 44.3%, 31.7%, and 23.9%, respectively, for patients with scores of 4 to 6. Hazard ratios of OS, LFS, and NRM all steadily increased for each additional score point. Importantly, the prognostic value of the EBMT risk score on OS, LFS, NRM, and relapse was maintained in the multivariate analysis. Moreover, considering the univariate analysis results of donor–recipient gender and mismatched allele-level HLA-A, -B, -C, and -DRB1 loci on patient outcomes and the fairly strong interaction between time from diagnosis to sUCBT and disease status, we developed a modified sUCBT-EBMT risk score by using degrees of 8-allele HLA match instead of donor type, donor–recipient gender combination, and time from diagnosis to sUCBT, and found that the modified score could also be used as a predictor for patient outcomes after sUCBT. The EBMT risk score is a good predictor of outcomes of patients with leukemia after sUCBT. The modified sUCBT-EBMT risk score can also be used as a pretransplant risk assessment, but this metric still requires further evaluation with a larger cohort. [ABSTRACT FROM AUTHOR]

Although previous studies have demonstrated improved outcomes in umbilical cord blood transplantation (UCBT) by omitting antithymocyte globulin (ATG) in the conditioning regimen, this approach has not been comparatively studied in unrelated peripheral blood stem cell transplantation (UPBSCT). To compare the risks and benefits between UCBT without ATG and UPBSCT in patients with acute leukemia (AL), we conducted a multicenter retrospective study of 79 patients who underwent UCBT (myeloablative conditioning without ATG) and 96 patients who underwent UPBSCT (myeloablative conditioning with ATG). The outcomes were graft failure, neutrophil engraftment, platelet engraftment, acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD), transplantation-related mortality (TRM), relapse, overall survival (OS), and leukemia-free survival (LFS). Follow-up was censored on October 31, 2016. Engraftment was similar between the 2 groups but granulocyte and platelet recovery were slower in the UCBT group (both P  < .001). The incidences of aGVHD, TRM, OS, and LFS were similar between the 2 groups (all P  > .05). Without ATG, the UCBT group displayed less cGVHD and less moderate and severe cGVHD ( P  < .001 and P  = .004). The incidences of Epstein-Barr virus viremia and post-transplantation lymphoproliferative disease were significantly lower in the UCBT group ( P  < .001 and P  = .037). UCBT recipients had higher activity Karnofsky performance scores and 3-year GVHD-free/relapse-free survival than the UPBSCT group ( P  = .03 and P  = .04). We observed similar survival when comparing UCBT without ATG and UPBSCT, but we also observed better quality of life in patients undergoing UCBT without ATG. We can therefore conclude that patients with primary AL for whom an appropriate HLA-matched sibling donor is not available could select either UCBT or UPBSCT. [ABSTRACT FROM AUTHOR]