Poor Survival of CD34 Positive and CD13/33 Positive Patients in Pediatric T-Cell Acute Lymphoblastic Leukemia Is Not Explained by Expression of Multidrug Resistance Genes.

For childhood T-ALL, the significance of early differentiation markers CD34 and CD13/33 in relation to outcome is unclear. In this study of 72 pediatric T-ALL patients, CD34 and CD13/33 expression was related to a poor 5 yrs survival (p=0.0013 for CD34⁺ and p=0.035 for CD33/CD13⁺). Expression of CD34 was associated with elevated MDR1 (p=0.01) and MRP1 (p=0.019) levels and CD13/33⁺ expression with MRP1 levels (p=0.028). However, none of these MDR genes independently predicted for poor outcome. We conclude that T-ALL with CD34 and CD13/33 expression has a relatively poor survival that is not explained by expression of MDR genes.