Expression of CD25 is a specific and relatively sensitive marker for the Philadelphia chromosome (BCR-ABL1) translocation in pediatric B acute lymphoblastic leukemia

Int J Clin Exp Pathol. 2014 Aug 15;7(9):6225-30. eCollection 2014.


Background: Precursor B acute lymphoblastic leukemia (B-ALL) is the most common cancer in children and overall, has an excellent prognosis. However, the Philadelphia chromosome translocation (Ph+), t(9;22)(q34;q11), is present in a small subset of patients and confers poor outcomes. CD25 (IL-2 receptor alpha chain) expression has been associated with Ph+ B-ALL in adults, but no similar study has been performed in pediatric B-ALL.

Methods: A retrospective analysis of 221 consecutive pediatric patients with a diagnosis of B-ALL (blood and/or bone marrow) from 2009 to 2012 was performed to determine an association between Ph+ B-ALL and CD25 expression. A threshold of 25% was used to define positive cases for CD25 expression by flow cytometry.

Results: There were 221 patients with a diagnosis of B-ALL ranging from 2 to 22 years (median, 6 years). Eight (3.6%) B-ALL patients were positive for the Philadelphia chromosome translocation (Ph+ B-ALL) and 213 were negative (Ph-negative B-ALL). CD25 expression was observed in 6 of 8 (75%) Ph+ B-ALL patients and 6 of 213 (2.8%) Ph-negative B-ALL patients. CD25 expression was significantly higher in Ph+ B-ALL compared to Ph-negative B-ALL, with median CD25 expression of 64% (range 0-93%) and 0.1% (range 0-91%), respectively (P ≤ 0.0002). Therefore, CD25 expression as a predictor of Ph+ B-ALL had 75% sensitivity, 97% specificity, 50% positive predictive value and 99% negative predictive value.

Conclusions: CD25 expression is a specific and relatively sensitive marker for the identification of Ph+ B-ALL in the pediatric population.

Keywords: B acute lymphoblastic leukemia; B-ALL; BCR-ABL; CD25; Ph+; Ph+ B-ALL; Philadelphia chromosome; flow cytometry; pediatric; t(9;22).

MeSH terms

  • Adolescent
  • Age Factors
  • Biomarkers, Tumor* / analysis
  • Biomarkers, Tumor* / genetics
  • Child
  • Child, Preschool
  • Female
  • Flow Cytometry
  • Fusion Proteins, bcr-abl / genetics*
  • Humans
  • Interleukin-2 Receptor alpha Subunit / analysis*
  • Male
  • Philadelphia Chromosome*
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / genetics*
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / immunology*
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / pathology
  • Predictive Value of Tests
  • Prognosis
  • Retrospective Studies
  • Translocation, Genetic*
  • Up-Regulation
  • Young Adult


  • BCR-ABL1 fusion protein, human
  • Biomarkers, Tumor
  • IL2RA protein, human
  • Interleukin-2 Receptor alpha Subunit
  • Fusion Proteins, bcr-abl