Potential of LightCycler technology for quantification of minimal residualdisease in childhood acute lymphoblastic leukemia

A certain quantity of residual leukemic cells at several time points during chemotherapy of childhood acute lymphoblastic leukemia (ALL) was proved to predict outcome. Future childhood ALL treatment will take minimal residual disease (MRD) into consideration for stratification aiming at an individua lization of chemotherapeutic regimens, Recently, the first quantitative rea l-time PCR assay for MRD detection was described using T cell receptor and immunoglobulin gene rearrangements as clonal markers, Quantitative real-tim e PCR was performed with TaqMan technology. Here, we present for the first time the potential of LightCycler real-time PCR technology to quantify MRD, We compare and assess different approaches for real-time PCR quantificatio n of leukemic cells, based either on clone-specific primers and general flu orescence detection with SYBR Green, TaqMan probe or hybridization probes, or based on general PCR amplification and clone-specific detection with hyb ridization probes. MRD quantification with LightCycler real-time PCR techno logy is a sensitive, specific and incomparably rapid method that needs no p ost-PCR handling, hence eliminating contamination risk and saving time. Wor king towards the establishment of MRD quantification in routine diagnostics and towards treatment strategies based on these results, LightCycler quant itative PCR seems to be a promising new technique that makes results immedi ately available for treatment decisions.