Minimal residual disease detection in Tunisian B-acute lymphoblastic leukemia based on immunoglobulin gene rearrangements

• Main Authors: S. Besbes, W.S. Hamadou, M.L. Boulland, Y.B. Youssef, B. Achour, H. Regaieg, A. Khelif, T. Fest, Z. Soua
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: IGH gene; IGK gene; B-ALL minimal residual disease (MRD); RQ-PCR
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017000100703&lng=en&tlng=en

IGH gene rearrangement and IGK-Kde gene deletion can be used as molecular markers for the assessment of B lineage acute lymphoblastic leukemia (B-ALL). Minimal residual disease detected based on those markers is currently the most reliable prognosis factor in B-ALL. The aim of this study was to use clonal IGH/IGK-Kde gene rearrangements to confirm B-ALL diagnosis and to evaluate the treatment outcome of Tunisian leukemic patients by monitoring the minimal residual disease (MRD) after induction chemotherapy. Seventeen consecutive newly diagnosed B-ALL patients were investigated by multiplex PCR assay and real time quantitative PCR according to BIOMED 2 conditions. The vast majority of clonal VH-JH rearrangements included VH3 gene. For IGK deletion, clonal VK1f/6-Kde recombinations were mainly identified. These rearrangements were quantified to follow-up seven B-ALL after induction using patient-specific ASO. Four patients had an undetectable level of MRD with a sensitivity of up to 10-5. This molecular approach allowed identification of prognosis risk group and adequate therapeutic decision. The IGK-Kde and IGH gene rearrangements might be used for diagnosis and MRD monitoring of B-ALL, introduced for the first time in Tunisian laboratories.