title: Minimal residual disease monitoring in childhood B lymphoblastic leukemia with t(12;21)(p13;q22); ETV6-RUNX1: concordant results using quantitation of fusion transcript and flow cytometry.
abstract: BACKGROUND
  The translocation t(12;21)(p13;q22) resulting in the fusion gene ETV6-RUNX1, is the most frequent gene fusion in childhood B lymphoblastic leukemia. In the Nordic Society of Paediatric Haematology and Oncology ALL-2008 treatment protocol, treatment stratification in B-lineage ALL is based on results of minimal residual disease (MRD) analysis with fluorescence-activated cell sorting (FACS). In this study, we determined whether RT-qPCR of the ETV6-RUNX1 fusion transcript can be a reliable alternative for MRD analysis.
  
  
  METHODS
  Seventy-eight bone marrow samples from 29 children at diagnosis and day 15, 29, and 78 during treatment were analyzed for MRD with FACS and with quantitative reverse transcription polymerase chain reaction (RT-qPCR). Fusion transcript MRD was defined as the ETV6-RUNX1/GUSB ratio at the follow-up time point (day 15/29/78) divided with the ETV6-RUNX1/GUSB ratio at diagnosis (%).
  
  
  RESULTS
  MRD analysis with FACS and with RT-qPCR of ETV6-RUNX1 fusion transcript showed strong correlation. All cases showed concordant results at the treatment stratifying time points day 29 and day 78, when comparing the two methods with a cutoff set to 0.1%.
  
  
  CONCLUSIONS
  RT-qPCR is a valuable addition and could also be an alternative to FACS in cases where FACS is not achievable for MRD analysis.
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: S J
authors.initials: SJ
authors.lastname: Alm
authors.affiliation: Ryhov County Hospital, Jonkoping, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Engvall
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.|Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Asp
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.|Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Palmqvist
authors.affiliation: Department of Pediatrics, The Queen Silvia Children's Hospital, Gothenburg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Abrahamsson
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.|Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: L
authors.identifier: http://orcid.org/0000-0003-3698-8519
authors.initials: L
authors.lastname: Fogelstrand
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002881:Chromosomes, Human, Pair 12; D002891:Chromosomes, Human, Pair 21; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics; D005434:Flow Cytometry / Q000592:standards*; D006801:Humans; D018365:Neoplasm, Residual / Q000175:diagnosis* / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000235:genetics; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000592:standards*; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D015514:Oncogene Proteins, Fusion; D012334:RNA, Neoplasm; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein
keywords: Acute lymphoblastic leukemia; ETV6-RUNX1; flow cytometry; minimal residual disease; quantitative PCR