Expression of CD25 is a specific and relatively sensitive marker for the Philadelphia chromosome (BCR-ABL1) translocation in pediatric B acute lymphoblastic leukemia |
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Authors: | Amos S Gaikwad Rachel E Donohue M Tarek Elghetany Andrea M Sheehan Xinyan Y Lu Maria M Gramatges Kenneth L McClain Toni-Ann Mistretta Jyotinder N Punia Timothy J Moore Tatiana Goltsova Michael Cubbage Choladda V Curry |
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Institution: | 1.Texas Children’s Cancer and Hematology Centers, Houston, Texas;2.Department of Pediatrics, Texas Children’s Hospital and Baylor College of Medicine, Houston, Texas;3.Department of Pathology, Texas Children’s Hospital and Baylor College of Medicine, Houston, Texas;4.Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas;5.Department of Hematopathology, MD Anderson Cancer Center, Houston, Texas |
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Abstract: | 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. |
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Keywords: | CD25 BCR-ABL Philadelphia chromosome Ph+ t(9 22) B acute lymphoblastic leukemia B-ALL Ph+ B-ALL flow cytometry pediatric |
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