目的 探讨儿童急性髓系白血病造血干细胞移植前后分子学微小残留病（molecular minimal residual disease, Mol-MRD）的预后意义。 方法 分析2016年8月—2023年12月接受造血干细胞移植的71例急性髓细胞性白血病患儿临床资料。对存在微小残留病（minimal residual disease, MRD）的患儿动态监测分子水平，并进行生存分析。 结果 移植前Mol-MRD≥0.01%者与<0.01%者3年总生存（overall survival, OS）率差异无统计学意义（77.3%±8.9% vs 80.4%±7.9%，P=0.705）。移植前Mol-MRD<1.75%的患儿3年OS率显著高于≥1.75%者（86.6%±5.6% vs 44.4%±16.6%，P=0.020）。长期存活组中位Mol-MRD为0.61%（0.04%~51.58%），明显低于死亡组Mol-MRD水平10.60%（1.90%~19.75%）（P=0.035）；同期流式MRD阳性率显著低于死亡组（24% vs 80%，P=0.039）。移植后30 d Mol-MRD≥0.01%者与<0.01%者的3年OS率差异无统计学意义（P=0.527）；移植后30 d Mol-MRD<0.22%的患儿3年OS率80.4%±5.9%，与融合基因阴性者（87.0%±7.0%）比较差异无统计学意义（P=0.523）。 结论 移植前Mol-MRD<1.75%、移植后Mol-MRD<0.22%的患儿经造血干细胞移植及相关干预手段仍可获得与融合基因阴性者一样的长期生存结局。

Objective To investigate the prognostic value of molecular minimal residual disease (Mol-MRD) monitored before and after allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric acute myeloid leukemia (AML). Methods Clinical data of 71 pediatric AML patients who underwent HSCT between August 2016 and December 2023 were analyzed. Mol-MRD levels were dynamically monitored in MRD-positive patients, and survival outcomes were evaluated. Results No significant difference in the 3-year overall survival (OS) rate was observed between patients with pre-HSCT Mol-MRD ≥0.01% and <0.01% (77.3% ± 8.9% vs 80.4% ± 7.9%, P=0.705). However, patients with pre-HSCT Mol-MRD <1.75% had a significantly higher 3-year OS rate than those with Mol-MRD ≥1.75% (86.6% ± 5.6% vs 44.4% ± 16.6%, P=0.020). The median Mol-MRD level in long-term survivors was significantly lower than in non-survivors [0.61% (range: 0.04%-51.58%)] vs 10.60% (range: 1.90%-19.75%), P=0.035]. Concurrent flow cytometry-based MRD positivity was significantly higher in non-survivors (80% vs 24%, P=0.039). There was no significant difference in the 3-year overall survival rate between patients with Mol-MRD ≥0.01% and those with <0.01% at 30 days post-HSCT (P=0.527). For children with Mol-MRD <0.22% at 30 days post-HSCT, the 3-year overall survival rate was 80.4% ± 5.9%, showing no significant difference compared to those with molecular negativity (87.0% ± 7.0%) (P=0.523). Conclusions Patients with pre-HSCT Mol-MRD <1.75% or post-HSCT Mol-MRD <0.22% may achieve long-term survival outcomes comparable to Mol-MRD-negative cases through HSCT and targeted interventions.