title: Evaluation of minimal residual disease by real-time quantitative PCR of Wilms' tumor 1 expression in patients with acute myelogenous leukemia after allogeneic stem cell transplantation: correlation with flow cytometry and chimerism.
abstract: Relapse remains the main cause of treatment failure in patients with acute myelogenous leukemia (AML) after allogeneic hemopoietic stem cell transplantation (SCT). The Wilms' tumor 1 gene (WT1) is reportedly overexpressed in >90% of patients with AML and thus can be useful for minimal residual disease (MRD) monitoring. The aim of this study was to evaluate the usefulness of WT1 expression as a relapse predictor marker in patients with AML after SCT and compare it with flow cytometry (FC) and chimerism studies. WT1 expression was assessed retrospectively using quantitative RT-PCR in bone marrow and peripheral blood from 21 patients. Patients were classified according to WT1 dynamics posttransplantation. Eleven of the 21 patients had low and stable WT1 levels. All of these 11 patients showed complete chimerism and negative MRD by FC and remained in complete remission with a median follow-up of 27 months (range, 18-98 months). In contrast, 10 of 21 patients showed WT1 overexpression after SCT, and 9 of these 10 patients relapsed. The incidence of relapse differed significantly between the 2 groups of patients according to WT1 expression post-SCT (P = .00003). Relapse in the 9 patients occurred at a median of 314 days (range, 50-560 days). Interestingly, in these patients, relapse was first predicted by WT1 (with negative FC and complete chimerism) in 7 patients. WT1 overexpression was correlated with disease burden in patients with AML before and after allogeneic SCT. In patients who relapsed, both medullary and extramedullary relapse were better anticipated by WT1 overexpression compared with FC and chimerism.
authors.affiliation: Department of Hematology, Hospital General Universitario Gregorio Marañón, Madrid, Spain. mkwon.hgugm@salud.madrid.org
authors.forename: Mi
authors.initials: M
authors.lastname: Kwon
authors.forename: Carolina
authors.initials: C
authors.lastname: Martínez-Laperche
authors.forename: María
authors.initials: M
authors.lastname: Infante
authors.forename: Fernando
authors.initials: F
authors.lastname: Carretero
authors.forename: Pascual
authors.initials: P
authors.lastname: Balsalobre
authors.forename: David
authors.initials: D
authors.lastname: Serrano
authors.forename: Jorge
authors.initials: J
authors.lastname: Gayoso
authors.forename: Ana
authors.initials: A
authors.lastname: Pérez-Corral
authors.forename: Javier
authors.initials: J
authors.lastname: Anguita
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Díez-Martín
authors.forename: Ismael
authors.initials: I
authors.lastname: Buño
mesh_terms: D000328:Adult; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000378:metabolism* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual; D012008:Recurrence; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018183:Transplantation Chimera; D014184:Transplantation, Homologous; D025721:WT1 Proteins / Q000096:biosynthesis* / Q000235:genetics; D009396:Wilms Tumor / Q000235:genetics / Q000378:metabolism; D055815:Young Adult
chemical_list: D025721:WT1 Proteins