目的 探讨脐带血造血干细胞移植（UCBT）治疗异染性脑白质营养不良（MLD）的安全性及有效性。方法 回顾性分析2019年4月至9月行非血缘UCBT治疗的3例MLD患儿的临床资料。结果 3例患儿均表现为走路障碍、进行性运动功能倒退，2例出现智力落后；3例均出现溶酶体芳基硫酸脂酶A（ARSA）下降，头部MRI均示脑白质不同程度的异常信号。3例均为ARSA基因复合杂合突变。3例均行非血缘UCBT，使用氟达拉滨+环磷酰胺+兔抗人胸腺细胞免疫球蛋白+白消安方案预处理，环孢素+吗替麦考酚酯+甲氨蝶呤预防移植物抗宿主病（GVHD）。3例均植入成功，移植后1个月内全血均达到完全供者嵌合状态，头部MRI均提示脑实质病变逐渐停止进展，ARSA均逐渐恢复正常。3例患儿均出现感染，2例出现急性移植物抗宿主反应（aGVHD），1例出现慢性移植物抗宿主反应（cGVHD），经抗感染及调节免疫治疗后均好转。末次随访时间为2022年8月，3例患儿均存活，其远期疗效及神经系统恢复情况仍需长期随访。结论 UCBT是阻止MLD进展的一种安全及有效治疗手段。

Objective To investigate the safety and efficacy of umbilical cord blood transplantation (UCBT) in the treatment of metachromatic leukodystrophy (MLD). Methods The clinical data of 3 MLD children treated with unrelated UCBT from April to September 2019 were retrospectively analyzed. Results All the 3 children showed walking disorder, progressive motor function regression, and 2 of them showed mental retardation. Lysosomal arylsulfatase A (ARSA) decreased in all of them. Head MRI of all the 3 children showed abnormal signals of different degrees in the white matter of the brain and they all had compound heterozygous mutations of ARSA gene. All the 3 children were treated with unrelated UCBT, and the pre-treatment regimen was fludarabine + cyclophosphamide + rabbit anti-human thymocyte immunoglobulin + busulfan, and the prevention of graft-versus-host disease (GVHD) was treated with cyclosporine + mycophenolate mofetil + methotrexate. All the 3 children were successfully implanted, and the whole blood of all children reached complete donor chimerism within 1 month after transplantation. Head MRI showed that the progression of brain parenchymal lesions gradually stopped, and ARSA levels gradually returned to normal. All 3 patients developed infection, 2 developed acute GVHD and 1 developed chronic GVHD. After anti-infection and regulatory immunotherapy, they all improved. The last follow-up was in August 2022, and all 3 patients survived. Long-term efficacy and neurological recovery still require long-term follow-up.Conclusion UCBT is a safe and effective treatment to prevent the progression of MLD.