急性B淋巴细胞白血病患儿微小残留病流式细胞术检测的临床意义

目的研究使用流式细胞术检测小儿急性B淋巴细胞白血病(acutelymphoblasticleukemia,ALL)微小残留病(minimalresidualdisease,MRD)的临床预后价值。方法能将残留白血病细胞与正常骨髓细胞区分开来的抗体组合称为有效抗体组合。我们使用流式细胞术对36例具有有效抗体组合的BALL患儿缓解后的骨髓标本进行MRD的定期检测。对6例无有效抗体组合的患儿,我们使用CD45/CD19/CD34/CD10与CD45/CD19/CD20/CD22两个抗体组合定期检测骨髓标本。结果(1)在42例患儿中有36例(86%)具有有效抗体组合;(2)在治疗6个月时间点时,MRD水平≥10-4的患儿(13例)无病生存率(diseasefreesurvival,DFS)与MRD水平<10-4的患儿(12例)相比无统计学意义(P=0.62);在治疗9个月时,MRD水平≥10-4的患儿(10例)要比MRD水平<10-4的患儿(13例)生存率低(P=0.025);在治疗12个月时,MRD水平≥10-4的患儿(8例)要比MRD水平<10-4的患儿(9例)生存率低(P=0.042);(3)共有7例患儿复发,其中6例复发患儿在复发前的4～10个月均检测到≥10-3水平的MRD。在随访过程中至少有1次MRD水平≥10-3患儿的无病生存率较MRD水平在10-3以下的患儿为低(P=0.003);(4)5例复发患儿的免疫表型基本未发生变化,只有1例丢失了CD13抗原;(5)在6例无有效抗体组合患儿中未发现有意义的MRD。结论(1)MRD水平在10-3或以上的患儿预后较差;(2)治疗9个月与12个月时间点的MRD水平有预后价值;(3)对于无有效抗体组合的患儿,CD45/CD19/CD34/CD10与CD45/CD19/CD20/CD22抗体组合的效果应进一步评估。

The clinical significance of detecting minimal residual disease in acute childhood B-cell lymphoblastic leukemia with flow cytometry

OBJECTIVE: Flow cytometry may be used to detect minimal residual disease (MRD) in acute lymphoblastic leukemia because leukemic cells often display aberrant phenotypes when compared to normal cells. The present study was designed to establish a flow cytometric method for detecting MRD in children with B-ALL and evaluate its clinical prognostic value. The investigators also aimed to study the value of the detection of MRD by flow cytometry in childhood B-ALL without effective antibody combinations. METHODS: Thirty-six cases of childhood B-ALL with effective antibody combinations were performed MRD analysis after induction therapy. The authors detected MRD in 6 cases without effective antibody combinations by the four-color antibody combinations consisting of CD(45)/CD(19)/CD(10)/CD(34) and CD(45)/CD(19)/CD(20)/CD(22) and detected the aberrance of the minor subsets of CD(19)(+) cells. RESULTS: (1) Forty-two cases of childhood B-ALL were screened for antibody combinations of interest and were identified in 86% (36/42) of the cases. The sensitivity of this method was 0.01%. (2) Patients with MRD levels > or = 0.01% at 9 and 12 months of therapy had significantly low disease-free survival compared with patients with MRD levels < 0.01%. (3) Six out of seven patients with recurrence in the BM had MRD levels > or = 0.1% prior to recurrence. Patients with MRD levels > or = 0.1% during chemotherapy had significantly low disease-free survival as compared with patients with MRD values < 0.1%. (4) Two out of seven patients with recurrence had positive results of the qualitative PCR prior to recurrence. (5) Five patients with recurrence had no shift of antigen expression at relapse except that a patient missed CD(13). (6) Detectable MRD was not found in six patients without effective antibody combinations. CONCLUSION: (1) Flow cytometry is a sensitive and specific method for detecting MRD of childhood ALL, and could predict the coming relapse. (2) Patients with MRD levels > 10(-3) had poor prognosis. (3) The levels of MRD at month 9 and 12 had prognostic value. (4) The value of antibody combinations consisting of CD(45)/CD(19)/CD(10)/CD(34) and CD(45)/CD(19)/CD(20)/CD(22) should be further investigated in patients without effective antibody combinations.