四色流式细胞术检测B细胞急性淋巴细胞白血病微量残留病的临床意义

目的探讨利用四色流式细胞术（FCM）检测B细胞急性淋巴细胞白血病（B-ALL）微量残留病（MRD）的临床意义.方法采用以抗CD34/CD10/CD45/CD19为主的两种四色荧光标记抗体组合,对98例B-ALL患者的671份骨髓标本和1份脑脊液标本进行FCM多参数MRD检测,98例随访患者中26例无发病初期的免疫分型资料.结果FCM检测显示白血病细胞＜0.0001（MRD阴性）的标本为579份;白血病细胞＞0.0001的样本数为93份,其中64份骨髓标本白血病细胞比例＜0.05,29份标本白血病细胞比例＞0.05,我们将其归为复发病例（包括治疗后未达CR的病例）.共20例患者复发,其中19例血液学复发,1例中枢神经系统复发.15例血液学复发者在复发前7～17周发现MRD阳性,包括发病时免疫分型资料不明者6例,MRD水平均＞0.0001;2例分别在复发前3个月和9个月检测MRD为阴性,此后中断检测.在诱导治疗结束和治疗3个月时,如果MRD水平＞0.0001,复发率为50%（12例中有6例复发）,而MRD阴性组复发率为7.5%（40例中有3例复发）（P=0.000）.结论利用FCM进行MRD跟踪监测可预测复发,治疗初期患者MRD＞0.0001,复发的危险性较高.而在掌握了正常B祖细胞抗原表达规律的基础上,可不完全依赖于发病时的免疫表型资料.

Clinical significance for minimal residual disease detection by 4 color flow cytometry in adult and childhood B lineage acute lymphoblastic leukemia

OBJECTIVE: To evaluate the clinical significance for minimal residual disease (MRD) detection by 4 color flow cytometry in B lineage acute lymphoblastic leukemia (B-ALL). METHODS: MRD was analyzed and followed up by using two panels of 4 color antibodies, mainly CD34/CD10/CD45/CD19, in 671 consecutive bone marrow specimens and 1 cerebrospinal fluid from 98 B-ALL patients. In 26 cases of them the immunophenotyping informations at diagnosis were not available. RESULTS: Of 671 bone marrow samples, 579 were MRD negative with leukemic cells below 0.0001 and 93 were MRD positive with leukemic cells over 0.0001. Of 93 MRD positive samples, leukemic cells below 0.05 were found in 64 bone marrow samples, meanwhile in the other 29 samples leukemic cells were over 0.05. Twenty patients relapsed, 19 were bone marrow relapse and one center nerves system. Fifteen of them were found MRD positive 7 - 17 weeks before relapse including 6 patients having no immunophenotyping data at diagnosis. The percentages of leukemia cells in these 15 patients were all over 0.0001. Two relapsed patients were MRD negative in 3 and 9 months before relapse, respectively. Two relapsed after MRD monitoring stopped. If MRD level was > 0.0001 at the end of induction chemotherapy and 12 weeks of treatment, the rate of relapse was 50% (6/12), while, it was 7.5% (3/40) in MRD negative patients (P = 0.000). CONCLUSION: Relapses can be predicted by MRD monitoring, if MRD was positive in the early phase of treatment, the risk of relapse was higher. Based on the characteristics of B cells ontogeny, MRD detection can be done independently of immunophenotypic information at diagnosis.