ASC0 2013：脐带血移植治疗白血病预后好

　　美国学者的一项研究首次报道了脐带血（UCB）移植的长期生存率。该资料持续支持无论是在缺乏HLA匹配的捐赠者的情况，还是当患儿为急性白血病需要紧急移植时，均可考虑UCB移植。

　　该研究纳入2000-2009年期间行骨髓移植治疗的18岁以下急性髓细胞或淋巴细胞白血病患儿，分别为接受HLA匹配的骨髓（BM）移植（N=5 205）或HLA不匹配的BM移植（N=5 112）或脐带血（UCB）移植（N=5 55）。用多变量回归模型来分析不同组之间生存率的区别。

　　结果显示，三组患者疾病特征相似，患者和移植者特征无显著差异。在多变量分析中，接受UCB移植和HLA匹配的BM移植后长期死亡率风险无显著差异（HR=0.83，p=0.41）。而HLA不匹配的BM移植患者死亡率风险显著比UCB移植患者（HR=1.66，p=0.03）和HLA匹配的BM移植患者（HR 2.00，p=0.008）更高。在该三组队列中，移植后1年内无病患者的预期8年总体生存率分别为78%、81% and 68%。

Long-term survival after alternative donor transplantation in children with acute leukemia
Background
Most reports describing long-term survival after allogeneic transplantation are in adults after transplantation of bone marrow (BM) from HLA-matched siblings. This report compares long-term survival after transplantation of unrelated donor BM to that after umbilical cord blood (UCB) in children with acute leukemia.
Methods
Included were patients aged less than 18 years with acute myeloid or lymphoblastic leukemia, alive and leukemia-free for at least 1 year after transplantation. Transplants occurred 2000-2009. Patients received BM grafts that were HLA-matched (N = 205) or mismatched at 1-HLA locus (N = 112) and UCB grafts that were matched (N = 55) or mismatched at 1 (N = 160) or 2 HLA-loci (N = 134). Multivariate Cox regression models were constructed to explore differences in survival between groups. UCB transplants were treated as a single group as there were no significant differences between HLA-matched and mismatched UCB grafts. Multivariate models held 3 treatment groups: HLA-matched BM, HLA-mismatched BM and UCB grafts.
Results
The disease characteristics of the three groups were similar. There were differences in patient and transplant characteristics. Recipients of UCB transplants were younger, more likely non-Caucasian, and more likely to have received a non-irradiation-containing conditioning regimen, in-vivo T-cell depletion and GVHD prophylaxis with cyclosporine and either prednisone or mycophenolate. In multivariate analysis, the risks of long-term mortality were not significantly different after UCB and HLA-matched BM transplants (HR 0.83, p=0.41). Mortality risks were significantly higher after HLA-mismatched BM transplants compared to UCB (HR 1.66, p=0.03) and HLA-matched BM transplants (HR 2.00, p=0.008). In this cohort, surviving disease-free at least 1-year after transplantation, the 8-year probabilities of overall survival after UCB, HLA-matched and HLA-mismatched BM transplants were 78%, 81% and 68%.
Conclusions
This is the first report to document long-term durability of UCB grafts. The data continue to support the use of UCB grafts either in the absence of an HLA-matched donor or when transplantation is needed urgently for children with acute leukemia.