title: [Detection of minimal residual disease in B lineage acute lymphoblastic leukemia by 4-color flow cytometry].
abstract: OBJECTIVE
  To evaluate the method and value of detecting bone marrow minimal residual disease (MRD) in B lineage acute lymphoblastic leukemia (B-ALL) by multiparameter flow cytometry (FCM).
  
  
  METHODS
  The FCM immunophenotyping of B-lymphocyte precursors in regenerating stage and MRD was analyzed by using two sets of 4-color antibody panels, including mainly CD34, CD10, CD45, CD19, in 26 regenerating bone marrow samples after chemotherapy and 297 consecutive bone marrow specimens from 50 patients with B-ALL, respectively. The immunophenotype of leukemia cells of B-ALL was also detected by four to six antibodies combination of 4-color CD45/SSC gating FCM. The CD19, CD10, CD34 fluorescence intensity of B-cell precursors in normal and leukemic bone marrow was compared by relatively quantitative method.
  
  
  RESULTS
  Twelve patients were MRD positive (MRD(+)) among 50 patients during MRD monitoring, the percentages of residual leukemia cells were 0.06% to 7.73%. Eleven cases displayed CD45, CD34, CD19, CD10 antigens aberrant expression. Five patients were bone marrow relapsed and 4 of them were MRD (+) 7-17 weeks before relapse. The percentages of leukemia cells in all the 4 patients were over 0.1%. Only one patient relapsed with MRD negative. The regenerated B precursors could be divided into 3 stages according to the expression of CD45, CD34, CD19, CD10, CD22, and CD20 antigens. Abnormal expression of CD45, CD34, CD19, and CD10 were detected in 71.8% of 213 patients with B-ALL, the percentage of only aberrant expression of CD38 and myeloid antigen was 8.1%.
  
  
  CONCLUSIONS
  Detection of MRD by multiparameter flow cytometry is a rapid, quantitative and sensitive approach, and has a higher predictability for relapse.
authors.affiliation: Institute of Hematology, People's Hospital of Peking University, Beijing 100044, China.
authors.forename: Yan-rong
authors.initials: YR
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Chang
authors.forename: Yi-fei
authors.initials: YF
authors.lastname: Cheng
authors.forename: Jia-yu
authors.initials: JY
authors.lastname: Fu
authors.forename: Le-ping
authors.initials: LP
authors.lastname: Zhang
authors.forename: Gui-lan
authors.initials: GL
authors.lastname: Liu
authors.forename: Shan-shan
authors.initials: SS
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D015448:Leukemia, B-Cell / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000175:diagnosis*