title: Immunophenotypic markers in adult acute lymphoblastic leukemia: the prognostic significance of CD20 and TdT expression.
abstract: BACKGROUND
  Efforts to overcome poor outcomes in patients with adult acute lymphoblastic leukemia (ALL) have focused on combining new therapeutic agents targeting immunophenotypic markers (IPMs) with classical cytotoxic agents; therefore, it is important to evaluate the clinical significance of IPMs.
  
  
  METHODS
  Baseline characteristics and clinical outcomes of patients with adult ALL were retrospectively analyzed. The percentage of blasts expressing IPMs at diagnosis was measured by multicolor flow cytometry analysis. Samples in which ≥20% of blasts expressed an IPM were considered positive.
  
  
  RESULTS
  Among the total patient population (N=230), almost all (92%) were in first or second hematological complete remission (HCR) and 54% received allogeneic hematopoietic cell transplant (allo-HCT). Five-year hematologic relapse-free survival (HRFS) and overall survival (OS) rates were 36% and 39%, respectively, and 45.6% and 80.5% of patients were positive for the IPMs CD20 and terminal deoxynucleotidyl transferase (TdT), respectively. Expression of CD20, CD13, CD34, and TdT was associated with HRFS rate, and expression of CD20 and CD13 was associated with OS rate, as was the performance of allo-HCT. In multivariate analysis, positivity for CD20 (HRFS: hazard ratio [HR], 2.21, P<0.001; OS: HR, 1.63, P=0.015) and negativity for TdT (HRFS: HR, 2.30, P=0.001) were both significantly associated with outcomes. When patients were categorized into three subgroups according to positivity for CD20 and TdT, there were significant differences in HRFS and OS among the subgroups.
  
  
  CONCLUSIONS
  Positivity for CD20 and TdT expression and clinical risk group were prognostic factors in adult ALL.
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dae-Young
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Han-Seung
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Choi
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jung-Hee
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Je-Hwan
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Mijin
authors.initials: M
authors.lastname: Jeon
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Young-Ah
authors.initials: YA
authors.lastname: Kang
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Young-Shin
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Miee
authors.initials: M
authors.lastname: Seol
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Young-Uk
authors.initials: YU
authors.lastname: Cho
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Seongsoo
authors.initials: S
authors.lastname: Jang
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Hyun-Sook
authors.initials: HS
authors.lastname: Chi
authors.affiliation: Department of Hematology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Kyoo-Hyung
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chan-Jeoung
authors.initials: CJ
authors.lastname: Park
keywords: Acute lymphoblastic leukemia; CD20; Immunophenotypic markers; TdT