摘要目的：分析儿童B系急性淋巴细胞性白血病（ B-ALL）中CD20表达和临床特点，探索CD20在评估预后中的作用。方法2008年11月至2012年7月上海市儿童医院初诊125例B系儿童急性淋巴细胞性白血病患儿，男79例，女46例，年龄2个月～14岁，所有患儿均应用流式细胞仪进行初诊时的免疫分型和微小残留病变（ MRD）筛选，对存在MRD标记的患儿在诱导缓解的第35天进行MRD监测。根据CD20表达将B-ALL患儿分为CD20阳性组和CD20阴性组，对各组的临床特点、免疫分型分期、MRD、危险分层和总体生存率等进行比较。采用χ2检验、t检验、方差分析以及生存分析进行统计学分析。结果初发B-ALL患儿共125例，CD20阳性组48例，阴性组77例，中位年龄6岁，中位随访时间为30个月。多因素COX分析显示CD20的表达与年龄、性别、初发时的白细胞计数、融合基因、免疫表型分期以及危险分层等均无差别； CD20阳性组患儿的第35天MRD阳性发生率为35.4％，明显大于CD20阴性组的16.9％，差异有统计学意义（χ2＝5.236，P＜0.05），而总体生存率（OS）为75.0％，明显小于CD20阴性组的84.4％，差异有统计学意义（χ2＝4.160，P＜0.05）。结论初发B-ALL的CD20阳性表达与ALL总体生存率低相关，可能为联合选择美罗华靶点的治疗方案提供依据。（中华检验医学杂志，2014，37：447-450）

abstractsObjective To analyzed the expression and clinical characteristics of CD 20 marker in children with B-lineage acute lymphoblastic leukemia ( B-ALL) and evaluated its medical significance in assessing the prognosis of disease.Methods From November 2008 to July 2012,125 cases of children with B-lineage acute lymphoblastic leukemia were collected from Shanghai Children ′s Hospital,including 79 males and 46 females, aged between 2 months to 14 years old.Flow cytometry based immunophenotyping and Minimal Residual Disease ( MRD) screening were applied to these children when newly diagnosed ,and MRD monitoring was again carried out after 35 days of induction remission therapy to those bears the MRD markers.These 125 patients were divided into CD20-positive group and CD20-negative group, and the corresponding clinical characteristics ,stage of immunophenotype ,MRD,risk stratification,and overall survival rates were recorded and compared.Data were statistically analyzed by using SPSS 16.0 software including χ2 test,t-test,standard deviation test and survival test.Results A total of 125 children with ALL-B,the group of CD20-positive were 48 while CD20-negative groups were 77,with a median age of 6 years old,and the median follow-up time of 30 months.Multivariate Cox regression Analysis showed that there was no clear correlation between CD20 expression level with age ,sex,white blood cell count at diagnosis ,fusion-gene,the stage of immunophenotype as well as risk stratification.The MRD-positive incidence at 35 days in the CD20 positive group was 35.4%,much higher than that of the CD20-negative group (16.9%),which is statistical significance (χ2 =5.236,P<0.05),while the overall survival rate (OS) for the CD20 positive group is 75.0%,much lower than that of the CD20 negative group (84.4%,χ2 =4.160,P<0.05).Conclusions&nbsp;CD20 positive expression level in children with B-lineage acute lymphoblastic leukemia at diagnosis demonstrates negative correlation with the overall survival rate of the patient ,indicating its usefulness as an additional joint marker for the current regimens to incorporate CD 20-targeted monoclonal therapy.