Simultaneous detection and quantification of minimal residual disease in childhood acute lymphoblastic leukaemia using real-time polymerase chain reaction

A number of prospective studies have indicated the clinical utility of meas uring minimal residual disease (MRD) in childhood acute lymphoblastic leuka emia (ALL) and have highlighted the need for improved methodology for quant ification of residual disease. We describe a novel real-time polymerase cha in reaction (PCR) strategy for MRD analysis based on the exonuclease activi ty of Taq polymerase to cleave a fluorescently labelled probe. Using a cons ensus probe designed to the framework 2 region of the IgH gene, together wi th leukaemia-specific primers, the utility of this technique for simultaneo us detection and quantification of MRD was demonstrated in samples from six ALL patients. This technique provides a rapid quantitative assay for deter mining MRD levels which lends itself to the routine monitoring of minimal r esidual leukaemia.