儿童急性淋巴细胞白血病微小残留病的流式细胞术分析

目的 根据白血病细胞的异常免疫表达,建立流式细胞术检测儿童急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)微小残留病(minimal residual disease,MRD)的方法 ,探讨流式细胞术检测MRD在儿童ALL个体化治疗中的意义.方法 用流式细胞术以多种四色荧光抗体组合对健康儿童骨髓进行检测,建立健康儿童骨髓细胞双参数点图分析模板.对75例ALL初诊患儿的骨髓细胞进行MRD筛选,找出在双参数点图上的位置明显区别于正常骨髓细胞的免疫表型组合作为MRD监测的有效免疫表型组合,对其中60例患儿诱导治疗结束及后续治疗中的骨髓标本用这些有效免疫表型组合进行MRD监测.同步进行细胞形态学检测和PCR检测29种融合基因、IgH/T淋巴细胞受体(TCR)基因重排.结果流式细胞术检出69例(92.0%)可用于MRD监测的有效免疫表型组合,PCR检出21例(28.0%)可用于MRD监测的融合基因或IgH/TCR基因重排;诱导治疗结束后及后续治疗中有25份骨髓标本细胞形态学未检出白血病残留细胞,流式细胞术检测仍有0.021%～4.130%的白血病残留细胞.结论 流式细胞术检测儿童ALL MRD能较好地评估临床缓解期间ALL患儿体内残留白血病细胞的数量,其覆盖面和速度优于PCR检测方法 ,敏感性高于形态学检测方法 .

Detection of minimal residual disease in childhood acute lymphoblastic leukemia by multi-parameter flow cytometry

Objective To establish a flow cytometric measurement of detecting minimal residual disease(MRD) according to the leukemia-associated immunophenotypes in children with acute lymphoblastic leukemia(ALL) and to explore the significance of MRD detection in ALL children for a individualized treatment. Methods A variety of four-color fluorescent antibody combinations were used to investigate the children's normal bone marrow. The normal bone marrow pattern at two-parameter plots was established to identify the residual tumor cells, seventy-five bone marrow samples from newly diagnosed ALL children were analyzed with four-color cytometry to determined the optimal combinations which can clearly distinguish the tumor cells from normal cells. The bone marrow samples were monitored with the combination panel in 60 patients at the end of induction therapy and follow-up treatment. Cytomorphology test, PCR amplification of 29 fusion genes as well as IgG and TCR gene rearrangements were performed simultaneously. Results Sixty-nine cases (92.0%) could be identified for effective antibody combinations to monitor MRD by four-color cytometry. Fusion genes or IgG and T cell receptor (TCR) gene rearrangements can be detected in 21 cases (28.0%) to monitor MRD by PCR. No MRD can be detected in 25 bone marrow samples at the end of induction therapy and follow-up treatment. Four-color cytometry could detect as low as 0.021%-4.130% residual leukemia cells. Conclusion MRD can be monitored by flow cytometry which is faster than PCR, and the sensitivity is superior to morphology method.