Implementation of a simplified flow cytometric assays for minimal residual disease monitoring in childhood acute lymphoblastic leukemia

Abstract

Background: Monitoring minimal residual disease (MRD) in B-lineage acute lymphoblastic leukemia (ALL) to assess treatment response is crucial for risk assignment. Flow cytometry can be used to monitor MRD in ALL but the implementation of this approach requires extensive expertise. If resources are limited, the costs of full flow cytometric MRD testing might be prohibitive. Objective: We evaluated the applicability of a previously reported simplified MRD assay, designed to distinguish leukemic from normal lymphoblastic during remission induction therapy. Methods: Fifty-nine samples from children with ALL, enrolled in the RE-LLA study at a pediatric oncology center in Recife (Brazil), were evaluated for MRD on day 19 and on day 26 of remission induction therapy. We compared results obtained by a trainee in Recife and an expert. Results: The method was implemented successfully and the concordance between results obtained by the trainee and the expert was practically absolute at the end of the study. Conclusions: It is possible to implement reliable measurements of MRD during remission induction therapy in childhood ALL despite limited resources. The simplicity of the MRD method used in this study does not require extensive prior training in leukemia immunophenotyping. © 2016 International Clinical Cytometry Society.