title: MRD detection of leukemia relapse using HLA typing by FACS in combination with FISH after mismatched allogeneic stem cell transplantation.
abstract: Loss of mismatched HLA is a cause of relapse following HLA-mismatched allo-SCT. We directly detected the loss of mismatched HLA alleles in relapsed leukemic cells at a MRD level using HLA typing by multicolor FACS (HLA-Flow) in combination with FISH in the BM of two patients with MLL-AF9-positive AML, at 6 and 10 months after mismatched allo-SCT. HLA-Flow with FISH analysis detected relapsed leukemic cells not expressing a mismatched HLA allele and harboring the MLL rearrangement. Simultaneously, real-time quantitative RT-PCR detected a low copy number of MLL-AF9 transcripts, consistent with MRD detection. HLA-Flow with FISH is a powerful method for detecting molecular relapse after mismatched allo-SCT and provides important information on the HLA expression status of the relapsed leukemic cells to help determine the next intervention.
authors.affiliation: Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Miyachi
authors.forename: Eri
authors.initials: E
authors.lastname: Watanabe
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Watanabe
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tsuma
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kawashima-Goto
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tamura
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Imamura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishida
authors.forename: Hajime
authors.initials: H
authors.lastname: Hosoi
mesh_terms: D000483:Alleles; D002469:Cell Separation; D002648:Child; D005260:Female; D005434:Flow Cytometry; D006680:HLA Antigens / Q000276:immunology*; D018380:Hematopoietic Stem Cell Transplantation; D006650:Histocompatibility Testing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D008297:Male; D009364:Neoplasm Recurrence, Local; D018365:Neoplasm, Residual / Q000175:diagnosis*; D014184:Transplantation, Homologous; D016896:Treatment Outcome
chemical_list: D006680:HLA Antigens
keywords: HLA-Flow; minimal residual disease; mismatched HLA allele; mismatched allo-SCT