Prospective comparison of two flow cytometry methodologies for monitoring minimal residual disease in a multicenter treatment protocol of childhood acute lymphoblastic leukemia.

Background: Minimal residual disease (MRD) is a powerful prognostic indicator in childhood acute lymphoblastic leukemia (ALL). Multiparametric flow cytometry (FC) is a rapid and sensitive methodology for detection of MRD, applicable for most patients and is being incorporated in multicenter treatment protocols. The influence of different techniques and of individual interpretation of data on the interlaboratory variability in FC-MRD determinations has not been described.