目的 探讨急性淋巴细胞白血病（ALL）复发患儿的临床特征及分析影响预后的因素。方法 选取 2006年2月至2019年12月接受国内儿童急性淋巴细胞白血病协作组方案治疗的458例初诊ALL儿童，回顾性分析76例复发ALL儿童的临床特征及影响预后因素。结果 本中心儿童ALL总体复发率为16.6%（76/458）；复发ALL患儿死亡率57.9%（44/76） ，复发ALL患儿5年总体生存率为（38.6±5.9）%。按复发时间分组，极早期复发26例、早期复发30例、晚期复发20例，三组5年总体总生存率（OS）差异有统计学意义（P<0.001）。按复发部位分组，单纯骨髓复发57例，髓外复发12例及髓内外联合复发7例，三组5年OS率差异有统计学意义（P<0.05）。76例复发儿童11例放弃治疗，65例接受再次治疗，未获得2次完全缓解（CR2）14例，获CR2 51例，两组5年OS率差异有统计学意义（P<0.001）。按照复发后治疗方式分组分为异基因造血干细胞移植组（Allo-HSCT）22例（33.8%），嵌合抗原受体T细胞疗法（CART）治疗组8例（12.3%），CART联合Allo-HSCT组14例（21.5%），单纯化疗和（或）靶向药物组21例（32.2%），组间比较5年OS率差异有统计学意义（P<0.001）。单因素预后分析显示初诊白细胞>100×10⁹/L、初诊危险度、复发时间、复发部位、复发后危险度、复发后治疗方案、是否获得CR2是影响复发ALL儿童预后的独立危险因素（P<0.05）。Cox回归模型进行多因素预后分析，极早期复发和复发后未获得CR2是影响复发ALL患儿预后的独立危险因素（P<0.05），复发后接受CART细胞衔接移植治疗是复发ALL患儿预后保护因素。结论 本中心儿童ALL复发时间以早期复发为主，复发部位以骨髓复发为主。多因素预后分析极早期复发和复发后未获得CR2是复发ALL患儿预后的独立危险因素（P<0.05）。CART联合Allo-HSCT可改善复发急淋患儿预后。

Objective To investigate the clinical characteristics and prognostic factors of children with relapsed acute lymphoblastic leukemia (ALL). Methods A total of 458 newly diagnosed ALL children who treated with the Chinese Children's Leukemia Group (CCLG) protocol at hospital between February 2006 and December 2019 were selected. Results The overall relapse rate of childhod ALL in this center was 16.6% (76/458). The mortality rate among relapsed ALL children was 57.9% (44/76), and the 5-year overall survival (OS) rate for relapsed ALL children was 38.6% ± 5.9%. Grouped by time to relapse, the cohort included 26 cases of very early relapse, 30 cases of early relapse, and 20 cases of late relapse. There was a statistically significant difference in the 5-year overall survival rate (OS) among the three groups(P<0.001). When categorized by relapse site, 57 cases involved isolated bone marrow relapse, 12 cases had extramedullary relapse, and 7 cases exhibited combined medullary/extramedullary relapse. There was a statistically significant difference in the 5-year OS rate among the three groups (P<0.05). Among the 76 relapsed children, 11 discontinued treatment, while 65 received retreatment. Among them, 14 failed to achieve a second complete remission (CR2), whereas 51 attained CR2. There was a statistically significant difference in the 5-year OS rate between the two groups (P<0.001). Based on post-relapse treatment modalities,the patients were divided into allogeneic hematopoietic stem cell transplantation (Allo-HSCT) group (22 cases, 33.8%), chimeric antigen receptor T-cell immunotherapy (CART) group (8 cases, 12.3%), CAR-T combined with Allo-HSCT group (14 cases, 21.5%), and chemotherapy and/or targeted therapy group (21 cases, 32.2%). There was a statistically significant difference in the 5-year OS rate among the groups (P<0.001). Univariate prognostic analysis revealed that initial white blood cell count>100×10⁹/L, initial risk stratification, relapse time, relapse site, post-relapse risk stratification, post-relapse treatment modality, and failure to achieve CR2 were independent risk factors affecting the prognosis of relapsed ALL children (P<0.05). Multivariate analysis using the Cox regression model identified very early relapse and failure to attain CR2 after relapse as independent risk factors for poor prognosis in relapsed ALL children (P<0.05), while post-relapse treatment with CAR-T bridging to allogeneic hematopoietic stem cell transplantation (Allo-HSCT) was a protective prognostic factor. Conclusions The predominant relapse pattern in our center was early recurrence, with bone marrow being the main relapse site. Multivariate analysis revealed that very early relapse and failure to achieve CR2 were independent adverse prognostic factors (P<0.05). CART combined with Allo-HSCT significantly improved outcomes in children with relapsed ALL.