New Insight Towards Prognosis in Pediatric Acute Myeloid Leukemia: Comparative Study.

Abstract

Wilms tumor gene (WT1) is a reliable marker for minimal residual disease assessment in acute leukemia children. This study was designed to demonstrate the potential use of WT1 to establish quality of remission in acute leukemia children for early identification of children at high risk of relapse. This study based on a quantitative Real–Time polymerase chain reaction (PCR) (TaqMan) assay in bone marrow samples collected from 45 acute myeloid leukemia children at diagnosis and during follow-up was established. Our results revealed, there was no significant association between WT1expression,at diagnosis, and either of gender, organomegally, total leucocytic count (TLC), French-AmericanBritish system (FAB) subtypes, CD34 expression, cytogenetic studies, percentage of blast infiltration or response to induction therapy. By comparing the results obtained at day 14 and those obtained at day 28, we cannot depend on WT1gene expression or MRD detection at day14 in predicting resistance to treatment or predicting mortality (p= 0.12). In contrast WT1 gene expression or MRD detection values after induction therapy (at day28) is an independent prognostic risk factor of relapse (p= 0.001) and death (p= 0.001). The blast percentage was significantly correlated to the WT1expression levels at day 28.The presence of MRD or WT1gene expression at the end of induction therapy is an extremely powerful adverse prognostic factor.WT1 at presentation has no prognostic significance whereas a high WT1 expression after induction therapy is a predictor for poor outcome. A rise inWT1expression during treatment is a predictor for relapse. WT1 expression is a valuable and important tool for MRD study in AML and the presence of MRD value at the end of induction therapy is an extremely powerful adverse prognostic factor despite of achievement of morphological remission.