目的 探讨流式细胞学检测儿童急性淋巴细胞白血病（ALL）中枢神经系统浸润阳性（CNSI⁺）患者的临床特征及其与预后的关系。方法 回顾性收集2008年4月至2013年6月CNSI⁺ALL患儿66例临床资料，对不同化疗阶段即诱导期、巩固维持期患儿的临床特征、实验室检查及预后进行比较分析。结果 66例CNSI⁺ALL患儿中，诱导期50例，巩固维持期16例。分子生物学结果显示巩固维持期CNSI⁺患儿预后良好基因比例明显高于诱导期患儿（P < 0.05），巩固维持期患儿复发率明显高于诱导期患儿（P < 0.05）。21例CNSI⁺ALL患儿复发，其中诱导期10例，巩固维持期11例，巩固维持期复发患儿中枢神经系统合并骨髓的复发比例明显高于诱导期复发患儿（P < 0.05），巩固维持期复发患儿脑脊液生化阳性率明显高于诱导期复发患儿（P < 0.05）。诱导期患儿无复发生存（RFS）率明显高于巩固维持期（P < 0.001），两组总体生存（OS）率比较差异无统计学意义（P > 0.05）。结论 ALL患儿CNSI⁺对不同化疗阶段RFS率有影响，但对OS率无明显影响；巩固维持期出现CNSI⁺的患儿复发率高，临床上应引起重视。

Objective To study the clinical features of central nervous system infiltration-positive (CNSI⁺) children with acute lymphoblastic leukemia (ALL) based on flow cytometry, as well as the association of such clinical features with prognosis. Methods A retrospective analysis was performed for the clinical data of 66 CNSI⁺ children with ALL treated from April 2008 to June 2013. Clinical features, laboratory examination results and prognosis were compared between the children in different chemotherapy stages (induction stage and consolidation/maintenance stage). Results Among the 66 CNSI⁺ children, 50 were in the induction stage and 16 in the consolidation/maintenance stage. Compared with the CNSI⁺ children in the induction stage, the CNSI⁺ children in the consolidation/maintenance stage had a significantly higher proportion of children with the genes associated with good prognosis based on the results of molecular biology (P < 0.05), as well as a significantly higher recurrence rate (P < 0.05). Recurrence was observed in 21 CNSI⁺ ALL children, among whom 10 were in the induction stage and 11 were in the consolidation/maintenance stage. Compared with the children experiencing recurrence in the induction stage, the children experiencing recurrence in the consolidation/maintenance stage had a significantly higher proportion of children with recurrence of the central nervous system and bone marrow (P < 0.05), as well as significantly higher proportion of biochemical positive rate of cerebrospinal fluid (P < 0.05). The children in the induction stage had a significantly higher recurrence-free survival rate than those in the consolidation/maintenance stage (P < 0.001), while there was no significant difference in overall survival rate between the two groups (P > 0.05). Conclusions In children with ALL, CNSI⁺ has a marked effect on recurrencefree survival rate in different chemotherapy stages, but has no obvious effect on overall survival rate. CNSI⁺ patients in the consolidation/maintenance stage have a higher recurrence.