摘要目的:通过基因表达谱研究儿童ETV6-RUNX1阳性急性淋巴细胞白血病（ALL）异质性，探索不同聚类分组临床特征，为临床个性化诊疗及利用测序技术探索预后相对不良组预测模型提供可行性参考。方法:应用改进的基因片段分析技术对2016年8月至2019年6月北京儿童医院收治的264例初诊ALL患儿的骨髓标本进行57个分型基因检测和聚类分析，重点分析56例ETV6-RUNX1阳性患者的基因表达谱与临床特点、免疫表型和早期化疗反应的关系。结果:基因分型聚类显示ETV6-RUNX1阳性ALL被分为两组：E/R-1组（45例，80.4%）和E/R-2组（11例，19.6%）。E/R-2聚类离散度大于E/R-1，spearman相关系数分别为0.788、0.901；E/R-2、E/R-1组初诊PLT中位数分别为104（27~644）×10 9/L、50（8~390）×10 9/L（ P<0.01），初诊骨髓原始幼稚细胞比例分别为0.830（0.270~0.975）、0.935（0.445~0.990）（ P<0.05）；CD22 +CD34 +CD20 -CD117 -CD56 -免疫组合在E/R-2组占比更高（ P<0.001）；E/R-2和E/R-1组化疗第33天流式细胞术检测的微小残留病（MRD）转阴例数分别为5例（55.6%）和32例（88.9%）（ P=0.064），去除临界值病例敏感性分析转阴例数分别为5例（55.6%）和32例（91.4%）（ P=0.035）；第33天PCR检测的MRD转阴例数分别为7例（77.8%）和36例（100.0%）（ P=0.047）。 结论:ETV6-RUNX1阳性ALL患儿在基因表达谱层面存在异质性，符合E/R-2表达特征的患儿可能初诊时血小板减少倾向小但早期化疗反应相对不良。

abstractsObjective:To evaluate the heterogeneity in pediatric ETV6-RUNX1 acute lymphoblastic leukemia (ALL) by gene expression profile and to study clinical characteristics in different clusters.Methods:An improved advanced fragment analysis (iAFA) technique was developed to detect 57 marker genes in 264 pediatric ALL patients treated in Beijing Children’s Hospital from August 2016 to June 2019. The 56 ALL patients with ETV6-RUNX1 positive were evaluated by clinical characteristics in gene expression profile, immunophenotype and early response of chemotherapy in different clusters.Results:The 56 ETV6-RUNX1-positive patients were clustered into 2 groups of E/R-1 (45, 80.4%) and E/R-2 (11, 19.6%) . Spearman coefficient was 0.788 and 0.901 in E/R-2 and E/R-1, respectively. The median of initial platelet counts was 104 (27-644) and 50 (8-390) ( P<0.01) in E/R-2 and E/R-1, respectively. The median of proportion of initial bone marrow immature cells was 0.830 (0.270-0.975) and 0.935 (0.445-0.990) ( P<0.05) in E/R-2 and E/R-1, respectively. The most specific immunophenotype at initial diagnosis, CD22 +CD34 +CD20 -CD117 -CD56 -, mainly gathered in E/R-2 ( P<0.001) . Patients negative of minimal residual disease detected by flow cytometry (MRD-FCM) at day 33 were 5 (55.6%) and 32 (88.9%) in E/R-2 and E/R-1, respectively. There was no significant difference in the original analysis ( P=0.064) but difference in sensitivity analysis ( P=0.035) . Nevertheless, patients negative of MRD detected by polymerase chain reaction (MRD-PCR) at day 33 were 7 (77.8%) and 36 (100%) in E/R-2 and E/R-1, respectively, with significant difference ( P=0.047) . Conclusion:Gene expression profile shows heterogeneous in ETV6-RUNX1 ALL, and the E/R-2 profile indicates that these patients may have a less tendency to thrombocytopenia at the initial diagnosis but have poorer response to induction chemotherapy and may influence further outcome.