IKZF1 Deletion Is An Independent Predictor of Outcome In Pediatric Acute Lymphoblastic Leukemia Treated According to the ALL-BFM 2000 Protocol

• Published in: Blood 2010-11, Vol.116 (21), p.409-409
• Main Authors: Breithaupt, Petra, Meissner, Barbara, Zimmermann, Martin, Möricke, Anja, Schrauder, André, Harbott, Jochen, Ludwig, Wolf-Dieter, Köhler, Rolf, Bartram, Claus R, Schrappe, Martin, Cario, Gunnar, Stanulla, Martin
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V116.21.409.409

Abstract 409 Alteration of the IKZF1 gene – encoding the transcription factor IKAROS, a key player in lymphoid development and tumor suppression – has been reported to be associated with a poor outcome in pediatric precursor B-cell ALL, especially in cases positive for the BCR-ABL1 fusion gene. In order to assess the prognostic value of IKZF1 deletions in a representative cohort of pediatric ALL patients treated on the German ALL-BFM 2000 study protocol, we screened 409 patients by applying a multiplex ligation-dependent probe amplification (MLPA) assay covering all eight IKZF1 exons (P335-A3 ALL-IKZF1 probemix; MRC-Holland, Amsterdam, The Netherlands). In ALL-BFM 2000, risk group stratification (standard, SR; intermediate, MR; high, HR) was based on minimal residual disease (MRD) analysis at two different time points (TP) and required two MRD targets with sensitivities of ≤10−4 (Flohr et al. Leukemia 2008). SR patients were MRD-negative on treatment days 33 (TP1) and 78 (TP2). HR patients had residual disease (≥10−3) at TP2. MRD MR patients had positive MRD detection at either one and or both time points but at a level of