不同诊断标准下儿童急性不明谱系白血病的临床特点和预后分析

目的 探索不同诊断标准下儿童急性不明谱系白血病（acute leukemias of ambiguous lineage，ALAL）的临床特点和预后。 方法 回顾性收集2015年12月至2019年12月诊治的39例儿童ALAL的临床资料，其中34例接受治疗。根据世界卫生组织和欧洲白血病免疫学分型协作组ALAL的诊断标准，将患儿分为ALAL组（28例）和伴髓系表达组（11例）。分析比较两组患儿临床特点、治疗及预后的差异。 结果 34例接受治疗的患儿3年无事件生存（event-free survival，EFS）率和总生存率分别为75%±9%和88%±6%。采用髓系方案、淋系方案、髓系方案诱导未缓解转淋系方案患儿的3年EFS率分别为33%±27%、78%±10%和100%±0%（P<0.05）。诱导治疗后微小残留病阴性的患儿3年EFS率高于阳性患儿（96%±4% vs 38%±28%，P<0.05）。ETV6-RUNX1阳性均在伴髓系表达组，BCR-ABL1阳性、MLL-r阳性、高白细胞（白细胞≥50×10⁹/L）均在ALAL组。伴髓系表达组和ALAL组的3年EFS率差异无统计学意义（100%±0% vs 66%±11%，P>0.05）。 结论 淋系方案治疗ALAL患儿的疗效优于髓系方案，诱导治疗后微小残留病阳性提示不良预后。伴髓系表达的患儿未合并高白细胞和不良遗传学改变，预后好，提示将其按ALAL诊断和治疗时需尤为谨慎。

Clinical features and prognosis of children with acute leukemias of ambiguous lineage under different diagnostic criteria

Objective To study the clinical features and prognosis of children with acute leukemias of ambiguous lineage (ALAL) under different diagnostic criteria. Methods A retrospective analysis was performed on the medical data of 39 children with ALAL who were diagnosed and treated from December 2015 to December 2019. Among the 39 children, 34 received treatment. According to the diagnostic criteria for ALAL by World Health Organization and European Group for the Immunological Characterization of Leukemias, the 39 children were divided into two groups: ALAL group (n=28) and myeloid expression group (n=11). The clinical features, treatment, and prognosis were compared between the two groups. Results The 34 children receiving treatment had a 3-year event-free survival (EFS) rate of 75%±9% and an overall survival rate of 88%±6%. The children treated with acute myeloid leukemia (AML) protocol had a 3-year EFS rate of 33%±27%, those treated with acute lymphoblastic leukemia (ALL) protocol had a 3-year EFS rate of 78%±10%, and those who had no remission after induction with AML protocol and then received ALL protocol had a 3-year EFS rate of 100%±0% (P<0.05). The children with negative minimal residual disease (MRD) after induction therapy had a significantly higher 3-year EFS rate than those with positive MRD (96%±4% vs 38%±28%, P<0.05). Positive ETV6-RUNX1 was observed in the myeloid expression group, and positive BCR-ABL1, positive MLL-r, and hyperleukocytosis (white blood cell count ≥50×109/L) were observed in the ALAL group. There was no significant difference in the 3-year EFS rate between the myeloid expression and ALAL groups (100%±0% vs 66%±11%, P>0.05). Conclusions ALL protocol has a better clinical effect than AML protocol in children with ALAL, and positive MRD after induction therapy suggests poor prognosis. Hyperleukocytosis and adverse genetic changes are not observed in children with myeloid expression, and such children tend to have a good prognosis, suggesting that we should be cautious to take it as ALAL in diagnosis and treatment.