title: Concurrent detection of minimal residual disease (MRD) in childhood acute lymphoblastic leukaemia by flow cytometry and real-time PCR.
abstract: Minimal (i.e. submicroscopic) residual disease (MRD) predicts outcome in childhood acute lymphoblastic leukaemia (ALL). To be used clinically, MRD assays must be reliable and accurate. Two well-established techniques, flow cytometry (FC) and polymerase chain reaction (PCR), can detect leukaemic cells with a sensitivity of 0.01% (10(-4)). We analysed diagnostic samples of 45 ALL-patients (37 B-lineage ALL, eight T-lineage ALL) by four-colour FC and real-time PCR. Leukaemia-associated immunophenotypes, at a sensitivity of MRD detection by FC at the 0.01% level, were identified in 41 cases (91%); antigen-receptor gene rearrangements suitable for MRD detection with a sensitivity of 0.01% or better by PCR were identified in 38 cases (84%). The combined use of FC and PCR allowed MRD monitoring in all 45 patients. In 105 follow-up samples, MRD estimates by both methods were highly concordant, with a deviation factor of <5 by Bland-Altman analysis. Importantly, the concordance between FC and PCR was also observed in regenerating bone marrow samples containing high proportions of CD19(+) cells, and in samples studied 24 h after collection. We conclude that both MRD assays yield generally concordant results. Their combined use should enable MRD monitoring in virtually all patients and prevent false-negative results due to clonal evolution or phenotypic shifts.
authors.affiliation: Department of Pediatric Haematology and Oncology, University Children's Hospital, D-72076 Tübingen, Germany. gunter.kerst@med.uni-tuebingen.de
authors.forename: Gunter
authors.initials: G
authors.lastname: Kerst
authors.forename: Hermann
authors.initials: H
authors.lastname: Kreyenberg
authors.forename: Carmen
authors.initials: C
authors.lastname: Roth
authors.forename: Catrin
authors.initials: C
authors.lastname: Well
authors.forename: Klaus
authors.initials: K
authors.lastname: Dietz
authors.forename: Elaine
authors.initials: E
authors.lastname: Coustan-Smith
authors.forename: Dario
authors.initials: D
authors.lastname: Campana
authors.forename: Ewa
authors.initials: E
authors.lastname: Koscielniak
authors.forename: Charlotte
authors.initials: C
authors.lastname: Niemeyer
authors.forename: Paul G
authors.initials: PG
authors.lastname: Schlegel
authors.forename: Ingo
authors.initials: I
authors.lastname: Müller
authors.forename: Dietrich
authors.initials: D
authors.lastname: Niethammer
authors.forename: Peter
authors.initials: P
authors.lastname: Bader
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005434:Flow Cytometry / Q000379:methods* / Q000592:standards; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D007223:Infant; D018365:Neoplasm, Residual; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor