Currently, qualification of clonal immunoglobulin and T-cell receptor rearrangements is considered to be a standard laboratory investigation to evaluate minimal residual disease in acute lymphoblastic leukemia. Benefit of this method contributes more often to therapeutic protocols that stratify patients into the groups according to the need of differently intensive therapy or particular therapeutic regimen. Regarding complexity of the method, it is necessary to follow technical and interpretative criteria that enable reproducibility and clinical validity of the method. The authors summarize current view on design and interpretation of this modern laboratory method. They also notice possible risks when these criteria were broken.

        Key words: acute lymphoblastic leukemia, RQ-PCR, Ig/TCR rearrangements, minimal residual disease