Evaluation of Minimal Residual Disease (MRD) by Quantification of TEL-AML1 Transcripts Is a Powerful Prognostic Tool in Children with T(12;21) Positive Acute Lymphoblastic Leukemia (ALL)

• Published in: Blood 2004-11, Vol.104 (11), p.322-322
• Main Authors: Cayuela, Jean-Michel, Ballerini, Paola, Romeo, Marina, Asnafi, Vahid, Auclerc, Marie-Francoise, Fund, Xavier, Delabesse, Eric, Bastard, Christian, Gabert, Jean, Vanier, Jean-Pierre, Lejars, Odile, Debre, Mariane, Pautard, Brigitte, Michel, Gerard, Leblanc, Thierry, Leverger, Guy, Chevret, Sylvie, Macintyre, Elisabeth, Baruchel, Andre
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V104.11.322.322

TEL-AML1 fusion transcripts are found in 25% of children with B-cell precursor ALL (BCP-ALL). From June 1993 to December 1999, 1195 children with BCP-ALL were included in the FRALLE 93 protocol. Out of these, 792 were evaluated for TEL-AML1 transcript expression. There is no difference in terms of initial features, DFS, EFS, survival between evaluated (792) and non evaluated (403) patients. Out of the 792 pts, 191 (24%) expressed TEL-AML1 transcripts at diagnosis. To assess the potential prognostic value of TEL-AML1 transcripts quantification, we have retrospectively analysed follow up marrow samples using Europe Against Cancer procedures for real time quantitative RT-PCR assay, on ABI PRISM 7700 (2 reference labs) and Light Cycler apparatus (1 reference lab). Out of the 191 TEL-AML1+ve pts, 83 were evaluated for MRD at different time points after induction therapy (median = D41 (34–55) (53 evaluable pts), at D111 (62–158) (62 pts), at D216 (159–325) (33 pts) and at D838 (365–1287) (49 pts). According to normalized Ct values, samples were attributed to 4 MRD level ranging from 0 to 3 and defined as follows: 0: Ct>40 ; 1 : 36