title: Development of an allele-specific minimal residual disease assay for patients with juvenile myelomonocytic leukemia.
abstract: Juvenile myelomonocytic leukemia is an aggressive and frequently lethal myeloproliferative disorder of childhood. Somatic mutations in NRAS, KRAS, or PTPN11 occur in 60% of cases. Monitoring disease status is difficult because of the lack of characteristic leukemic blasts at diagnosis. We designed a fluorescently based, allele-specific polymerase chain reaction assay called TaqMAMA to detect the most common RAS or PTPN11 mutations. We analyzed peripheral blood and/or bone marrow of 25 patients for levels of mutant alleles over time. Analysis of pre-hematopoietic stem-cell transplantation, samples revealed a broad distribution of the quantity of the mutant alleles. After hematopoietic stem-cell transplantation, the level of the mutant allele rose rapidly in patients who relapsed and correlated well with falling donor chimerism. Simultaneously analyzed peripheral blood and bone marrow samples demonstrate that blood can be monitored for residual disease. Importantly, these assays provide a sensitive strategy to evaluate molecular responses to new therapeutic strategies.
authors.affiliation: Department of Pediatrics, University of California, San Francisco, CA 94143, USA.
authors.forename: Sophie
authors.initials: S
authors.lastname: Archambeault
authors.forename: Nikki J
authors.initials: NJ
authors.lastname: Flores
authors.forename: Ayami
authors.initials: A
authors.lastname: Yoshimi
authors.forename: Christian P
authors.initials: CP
authors.lastname: Kratz
authors.forename: Miriam
authors.initials: M
authors.lastname: Reising
authors.forename: Alexandra
authors.initials: A
authors.lastname: Fischer
authors.forename: Peter
authors.initials: P
authors.lastname: Noellke
authors.forename: Franco
authors.initials: F
authors.lastname: Locatelli
authors.forename: Petr
authors.initials: P
authors.lastname: Sedlacek
authors.forename: Christian
authors.initials: C
authors.lastname: Flotho
authors.forename: Marco
authors.initials: M
authors.lastname: Zecca
authors.forename: Peter D
authors.initials: PD
authors.lastname: Emanuel
authors.forename: Robert P
authors.initials: RP
authors.lastname: Castleberry
authors.forename: Charlotte M
authors.initials: CM
authors.lastname: Niemeyer
authors.forename: Peter
authors.initials: P
authors.lastname: Bader
authors.forename: Mignon L
authors.initials: ML
authors.lastname: Loh
mesh_terms: D000483:Alleles; D001853:Bone Marrow / Q000378:metabolism; D002648:Child; D046528:Chimerism; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D054429:Leukemia, Myelomonocytic, Juvenile / Q000175:diagnosis* / Q000235:genetics* / Q000601:surgery; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*; D012008:Recurrence; D012680:Sensitivity and Specificity