title: Different mechanisms causing loss of mismatched human leukocyte antigens in relapsing t(6;11)(q27;q23) acute myeloid leukemia after haploidentical transplantation.
abstract: Mismatched human leukocyte antigens (HLAs) on leukemic cells can be targeted by donor T cells in HLA-mismatched/haploidentical stem cell transplantation. In two cases of acute myeloid leukemia with t(6;11)(q27;q23) abnormality presented here, flow cytometry analysis showed a lack of HLA-A unshared between recipients and donors in relapsing leukemic cells after HLA-haploidentical transplantation. However, high-resolution HLA genotyping showed that one case lacked a corresponding HLA haplotype, whereas the other preserved it. These cases suggest that leukemic cells, which lacked mismatched HLA expression, might have an advantage in selective expansion under donor T-cell immune surveillance after HLA-haploidentical transplantation. Most importantly, down-regulation of unshared HLA expression potentially occurs by genetic alterations other than loss of HLA alleles.
authors.affiliation: Division of Hematology, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan. tamakhi@hyo-med.ac.jp
authors.forename: Hiroya
authors.initials: H
authors.lastname: Tamaki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujioka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ikegame
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoshihara
authors.forename: Katsuji
authors.initials: K
authors.lastname: Kaida
authors.forename: Kyoko
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Ruri
authors.initials: R
authors.lastname: Kato
authors.forename: Taduko
authors.initials: T
authors.lastname: Tokugawa
authors.forename: Jun
authors.initials: J
authors.lastname: Nakata
authors.forename: Takayuki
authors.initials: T
authors.lastname: Inoue
authors.forename: Aya
authors.initials: A
authors.lastname: Yano
authors.forename: Ryoji
authors.initials: R
authors.lastname: Eguchi
authors.forename: Masaya
authors.initials: M
authors.lastname: Okada
authors.forename: Etsuko
authors.initials: E
authors.lastname: Maruya
authors.forename: Hiroh
authors.initials: H
authors.lastname: Saji
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D016026:Bone Marrow Transplantation; D002880:Chromosomes, Human, Pair 11 / Q000276:immunology; D002896:Chromosomes, Human, Pair 6 / Q000276:immunology; D005260:Female; D006086:Graft vs Host Disease / Q000235:genetics; D006680:HLA Antigens / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes; D018380:Hematopoietic Stem Cell Transplantation; D006648:Histocompatibility; D006650:Histocompatibility Testing; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000276:immunology; D012008:Recurrence; D013601:T-Lymphocytes / Q000276:immunology; D014019:Tissue Donors; D014178:Translocation, Genetic / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D006680:HLA Antigens