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Single vs double-unit cord-blood transplantation in children and young adults with residual leukemic disease
Balligand, L., Galambrun, C., Sirvent, A., Roux, C., Pochon, C., Bruno, B., Jubert, C., Loundou, A., Esmiol, S., Yakoub-Agha, I., et al
Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation. 2018
Abstract
We previously reported in a French prospective randomized study that transplantation of 2 unrelated cord blood (UCB) units instead of 1 does not decrease the risk of transplantation failure but may enhance alloreactivity. We present here the influence of pre-transplant minimal residual disease (MRD) on leukemia relapse and survival after single versus double-UCB transplantation. Among 137 children and young adults who were transplanted in the randomized study, 115 had available MRD assessment immediately before their conditioning regimen. MRD was considered positive when ≥ 10(-4), which was the case of 43 out of 115 patients. Overall, the 3-year survival probability was 69.1+/-4.4% and it was not significantly influenced by the MRD level: 70.7+/-5.4% in MRD- (<10(-4)) patients (n=72), 71.1+/-9.4% in MRD+ with 10(-4)≤MRD<10(-3) (n=26), and 58.8+/-11.9% in MRD+ ≥ 10(-3) patients (n=17). In the MRD+ group, we found a significantly lower risk of relapse in the double- versus single-unit arm (10.5+/-7.2% vs 41.7+/-10.4%; p=0.025) leading to a higher 3-year survival rate (82.6+/-9.3% vs 53.6+/-10.3%, p=0.031). This difference was only observed in patients who had not received anti-thymocyte globulin (ATG) during their conditioning regimen. In the MRD- group, no difference was found between the single- and the double-unit arms. We conclude that, even in case of positive pre-transplant MRD, UCB transplantation in children and young adults with acute leukemia results in a high cure rate and that a double-unit strategy may enhance graft-vs-leukemia effect and survival in these patients.