Immunophenotypic markers in adult acute lymphoblastic leukemia: the prognostic significance of CD20 and TdT expression

• Published in: Blood research Vol. 50; no. 4; pp. 227 - 234
• Main Authors: Kim, Dae-Young, Park, Han-Seung, Choi, Eun-Ji, Lee, Jung-Hee, Lee, Je-Hwan, Jeon, Mijin, Kang, Young-Ah, Lee, Young-Shin, Seol, Miee, Cho, Young-Uk, Jang, Seongsoo, Chi, Hyun-Sook, Lee, Kyoo-Hyung, Park, Chan-Jeoung
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Hematology; Korean Society of Blood and Marrow Transplantation; Korean Society of Pediatric Hematology-Oncology; Korean Society on Thrombosis and Hemostasis 01.12.2015; 대한혈액학회
• Subjects: Original; 병리학; CD20; Immunophenotypic markers; Acute lymphoblastic leukemia; TdT
• ISSN: 2287-979X; 2288-0011
• DOI: 10.5045/br.2015.50.4.227

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. 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. 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. Positivity for CD20 and TdT expression and clinical risk group were prognostic factors in adult ALL.