Expression of CD66c and CD25 in acute lymphoblastic leukemia as a predictor of the presence of BCR/ABL rearrangement

• Main Authors: Tarek M. Owaidah, Faisal I. Rawas, Mazen F. Al khayatt, Nasser B. Elkum
• Format: Article
• Language: English
• Published: Elsevier 2008-01-01
• Series: Hematology/Oncology and Stem Cell Therapy
• Online Access: http://www.sciencedirect.com/science/article/pii/S1658387608500586

BACKGROUND: Expression of myeloid or T cell lymphoid in precursor B cell acute lymphoblastic leukemia (pre-B cell ALL), which is referred to as aberrant expression, is quite a common phenomenon. CD66c is a myeloid marker which has aberrant expression in pre-B cell ALL, with strong correlation with non-random genetic changes (BCR/ABL rearrangement). Another leukemia associated marker (CD25) is frequently expressed in pre-B cell ALL. The frequency of CD25–expressing lymphoblasts has been found to be significantly higher in BCR/ABL-positive vs. BCR/ABL-negative patients. METHODS: In a cohort of 103 patients diagnosed with pre-B cell ALL or biphenotypic leukemia and studied for expression of CD66c and CD25 at presentation, we evaluated the frequency of expression of either or both in BCR/ABL positive cases. RESULTS: Surface CD66c was expressed by 70 cases (68%) and CD25 was expressed by 33 cases (32%) while both were expressed together on 29 cases (28%). BCR/ABL was positive in 18/103 patients. All BCR/ABL positive cases were positive for surface CD66c and CD25. CONCLUSION: Positivity for both leukemia-associated antigens CD66c and CD25 in combination can predict the presence of BCR/ABL rearrangement in pre-B cell ALL. While this finding does not replace the detection of BCR/ABL abnormality by cytogenetic or molecular techniques, it does provide an early and handy tool for prediction and management of high-risk cases of pre-B cell ALL, especially in centers with limited laboratory facilities.