Immunoglobulin/T-cell receptor gene rearrangements in the diagnostic paradigm of pediatric patients with T-cell acute lymphoblastic leukemia

摘要

Acute lymphoblastic leukemia (ALL) is the most common malignancy occurring in children. ALL is classified into two major subtypes: precursor B-cell acute lymphoblastic leukemia (precursor B-ALL) and T-cell acute lymphoblastic leukemia (T-ALL) [1]. With current therapeutic protocols the majority of patients with T-ALL reach remission; however, many of them suffer from relapse, which remains the most common causative factor of therapy failure. The detection of minimal residual disease (MRD) at the end of induction therapy (day 33) and subsequently at the beginning of consolidation therapy (week 12) has been proven extremely reliable in assessing subclinical levels of residual leukemic cells. Therefore, monitoring MRD kinetics at these two time-points has been incorporated into many European ALL treatment protocols as a crucial risk stratification factor [2-4]. Even more than in precursor B-ALL, in T-ALL MRD remains the strongest clinically significant prognostic factor recognized so far, implemented into regular therapeutic protocols and useful in the assessment of newly identified prognostic factors [4-6].