Kinetics of minimal residual disease response following induction therapy are predictive of subsequent relapse risk in AML.
 The predictive value of MRD assessment by WT1 RQ-PCR assay was determined in a cohort of 142 patients with AML treated with conventional anthracycline- and cytarabine-based treatment. Analysis was undertaken in patients with AML with WT1 expression exceeding 2 × 10⁴ copies/10⁴ABL copies in pre-treatment samples, allowing the detection of at least a 2-log reduction in WT1 transcripts following induction, taking into account the background level of expression observed in normal hematopoietic tissues.³⁸ The patient cohort included 91 cases reported previously³⁸ combined with a further 51 cases treated in the MRC AML15 trial (samples kindly provided by John Yin and Michelle Sale, Manchester Royal Infirmary, and analyzed by Neesa Bhudia, Guy’s Hospital, London, UK). Samples were analyzed with a standardized WT1 RQ-PCR assay (Ipsogen, Marseille, France) developed within the European LeukemiaNet, as described.³⁸