流式细胞术检测儿童B细胞急性淋巴细胞白血病微小残留病

目的建立流式细胞术检测白血病微小残留病(minimal residue disease，MRD)的方法，初步探讨其临床价值。方法用多种四色荧光抗体组合对患儿初发时的白血病细胞进行检测，同时对照多份正常骨髓标本的检测结果，以能够使白血病细胞在双参数点图上出现的位置完全不同于正常骨髓细胞的位置的抗体组合作为有效组合，以这些有效抗体组合对患诱导治疗结束后的骨髓标本进行监测。对58例B细胞急性淋巴细胞白血病(B-ALL)患儿初诊时的骨髓标本进行了抗体组合有效性的筛选，并对其中的30例患儿诱导治疗结束后的骨髓细胞进行了监测。结果有52例(89．7％)B-ALL患儿都可找到适用于MRD检测的抗体组合。四色组合由CD10／CD34/CD39外加一个有效标志如CD38、CD65、CD66c、CD21等组成。该方法的敏感度为0．01％，远高于形态学检测法。实验中8例患儿诱导治疗结束后的骨髓细胞形态学检测未见白血病残留细胞，但该方法检测结果白血病残留细胞分别为0．028％，1．430％，3．050％，0．015％，5．660％，2．700％，，0．027％和0．069％。结论流式细胞术检测MRD能提高对临床缓解期间患体内残存白血病细胞数量的评估能力。

Detection of minimal residual disease in childhood B-ALL by flow cytometry

Objective To establish a flow cytometric method for detecting minimal residual disease (MRD) in children with B-ALL and evaluate its clinical application.Methods Fifty-eight childhood B-ALL cases entered this study and 30 MRD analyses were performed after remission induction therapy. Four-color fluorochrome labeled monoclonal antibodies were used to analyze the cell immunophenotypes. Cells from normal bone marrow were used as controls. The leukemic cell populations located in flow cytometry dot plots different from those of normal were considered to be the markers of interest in the first step screening, and then used to monitor MRD step after therapy. Results Fifty-eight cases of childhood B-ALL were screened for antibodies combinations of interest and were identified in 89.7%(52/58) of these cases. The four-color antibody combinations consisted of CD 10 /CD 34 /CD 19 plus another effective marker such as CD 38 , CD 65 , CD 66c , CD 21 . The sensitivity of this method was 0.01%, much higher than microscopic inspection. In 8 cases whose bone marrow microscopically showed no residual leukemic cells, the percentage of leukemic cells were identified with this method of 0.028%, 1.430%, 3.050%, 0.015%, 5 660%, 2.700%, 0.027%, and 0.069%, respectively. Conclusion The application of flow cytometry in MRD monitoring can significantly improve the detection sensitivity in childhood B-ALL, thus facilitate the further treatment decision and follow-up.