title: [Clinical significance of monitoring E2A- PBX1 fusion gene expression in patients with allogeneic hematopoietic stem cell transplantation].
abstract: OBJECTIVE
  To investigate the clinical characteristics of E2A-PBX1（immunoglobulin enhancer binding factor-pre-B leukemia）fusion gene in patients with acute lymphoblastic leukemia（ALL） after allogeneic stem cell transplantation（allo-HSCT）.
  
  
  METHODS
  Clinical data of 10 patients received allo- HSCT in Peking University Institute of Hematology from December 2010 to January 2015 were retrospectively collected. The E2A-PBX1 gene was examined by real-time quantitative polymerase chain reaction（RQ- PCR）. The correlation between its expression level and the disease status was analyzed.
  
  
  RESULTS
  Among 10 cases of enrolled ALL, the E2A-PBX1 expression of six patients converted to positive after transplant at a median time of 90 days（range, 75-180 days）. The expression level of the first positive sample was 25.200%（range, 0.022%-353.600%）. The duration from E2A-PBX1 positive to hematological relapse was 30 days（range, 0-74 days）. Finally, 4 patients underwent relapse at a median time of 164 days （range, 75- 240 days） after allo- HSCT. The expression of E2A- PBX1 and minimal residual disease （MRD）level examined by flow cytometry were positive correlated（Spearman r=0.743, P=0.002）. Once E2A-PBX1 expression converted to positive after transplant, MRD would increase rapidly. Patients with this type of ALL would have little response to the current intervention towards relapse.
  
  
  CONCLUSIONS
  Monitoring E2A-PBX1 by RQ-PCR could be used to evaluate MRD status after allo-HSCT. Patients with positive E2A-PBX1 at early stage of transplant will have a poor prognosis.
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Xiaosu
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Yazhen
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Yongyan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Fengrong
authors.initials: F
authors.lastname: Wang
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Jingzhi
authors.initials: J
authors.lastname: Wang
authors.affiliation: Peking University People's Hospital, Peking University Institute of Hematology, Beijing 100044, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Huang
mesh_terms: D005434:Flow Cytometry; D018380:Hematopoietic Stem Cell Transplantation; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D018365:Neoplasm, Residual; D015514:Oncogene Proteins, Fusion / Q000378:metabolism*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000628:therapy; D060888:Real-Time Polymerase Chain Reaction; D012008:Recurrence; D012189:Retrospective Studies
chemical_list: D018398:Homeodomain Proteins; D015514:Oncogene Proteins, Fusion; C089847:E2A-Pbx1 fusion protein