Primers and protocols for standardized detection of minimal residual disease in acute lymphoblastic leukemia using immunoglobulin and T cell receptorgene rearrangements and TAL1 deletions as PCR targets - Report of the BIOMED-1 CONCERTED ACTION: Investigation of minimal residual disease in acute leukemia

It is now widely accepted that the detection of minimal residual disease (M RD) has prognostic value in acute leukemia. However clinical MRD studies ne ed standardized techniques. Therefore, several European laboratories have a ligned their goals and performed comparative studies to achieve optimizatio n and standardization of MRD techniques. This was achieved via the BIOMED-1 Concerted Action "Investigation of minimal residual disease in acute leuke mia: International standardization and clinical evaluation." This report de scribes the development of PCR primers and protocols for the detection of M RD in acute lymphoblastic leukemia (ALL) using clone-specific junctional re gions of immunoglobulin and T cell receptor gene rearrangements and TALI de letions as PCR targets. A total of 54 primers was developed (1) to amplify rearrangements of the TCRD, TCRG, and IGK (Kde) genes as well as TAL1 delet ions; (2) to sequence the junctional regions and breakpoint fusion regions; and (3) to perform MRD detection in bone marrow or peripheral blood sample s during follow-up of ALL patients. Protocols were established to identify PCR targets at diagnosis by performing 25 PCR reactions per patient using a ppropriate positive and negative controls. Standardized protocols were deve loped for MRD monitoring via single amplification of the PCR target followe d by dot blot hybridization with the corresponding patient-specific junctio nal region probe. In addition, alternative approaches were designed for cas es where the target sensitivity of at least 10(-4) was not obtained. The st andardization described here of MRD-PCR techniques is essential for the pro cess of translating WIRD research into clinical practice.