title: Haploidentical and Matched Sibling Donor Hematopoietic Cell Transplantation for Patients with HLA-Homozygous Haplotypes.
abstract: More than 1% of the Japanese population has HLA-homozygous haplotypes. For patients with such haplotypes, HLA-haploidentical family members who have no HLA mismatch in the graft-versus-host direction are readily available donor candidates for hematopoietic cell transplantation (HCT). In this study, the outcomes of patients with homozygous HLA-A, -B, and -DRB1 antigens who received HCT without T cell depletion from a haploidentical related donor with mismatches in the host-versus-graft direction only (hetero-to-homo, n = 78) or from an HLA-matched sibling donor (MSD) (MSD-homo, n = 153) were compared with those in patients with heterozygous haplotypes who received HCT from an MSD (MSD-hetero, n = 7242). Transplant outcomes in the hetero-to-homo group were similar to those in the MSD-hetero group regarding neutrophil engraftment, grades III to IV acute graft-versus-host disease (aGVHD), nonrelapse mortality (NRM), relapse, and overall survival. On the other hand, the incidences of severe aGVHD and NRM in the MSD-homo group were significantly lower than those in the MSD-hetero group (grades III to IV aGVHD: aHR .50, P = .034; NRM: aHR .48, P = .004). In conclusion, patients with HLA-homozygous haplotypes achieved lower GVHD and NRM rates for MSD transplantation than those with HLA-heterozygous haplotypes. When an MSD or an appropriate alternative donor is not available for patients with HLA-homozygous haplotypes who need immediate transplantation, transplantation from a haploidentical donor without T cell depletion is a viable option, given the comparable transplant outcomes for hetero-to-homo HCT and MSD-hetero HCT.
authors: Division of Hematology, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors: Junya
authors: J
authors: Kanda
authors: Division of Hematology, Department of Internal Medicine, Hyogo College of Medicine, Hyogo, Japan.
authors: Kazuhiro
authors: K
authors: Ikegame
authors: Department of Hematopoietic Stem Cell Transplantation, National Cancer Center Hospital, Tokyo, Japan.
authors: Shigeo
authors: S
authors: Fuji
authors: Department of Cell Therapy and Transplantation Medicine, The University of Tokyo Hospital, Tokyo, Japan.
authors: Mineo
authors: M
authors: Kurokawa
authors: Department of Hematology, Kanagawa Cancer Center, Kanagawa, Japan.
authors: Heiwa
authors: H
authors: Kanamori
authors: Department of Hematopoietic Stem Cell Transplantation, National Cancer Center Hospital, Tokyo, Japan.
authors: Takahiro
authors: T
authors: Fukuda
authors: Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan.
authors: Kazuteru
authors: K
authors: Ohashi
authors: Department of Hematology and Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors: Jun
authors: J
authors: Ishikawa
authors: Division of Hematology, Department of Internal Medicine, Hyogo College of Medicine, Hyogo, Japan.
authors: Hiroyasu
authors: H
authors: Ogawa
authors: Department of Hematology/Oncology, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan.
authors: Masami
authors: M
authors: Inoue
authors: Department of Hematology and Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
authors: Tatsuo
authors: T
authors: Ichinohe
authors: Japanese Data Center for Hematopoietic Cell Transplantation, Nagoya, Japan; Department of Healthcare Administration, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Yoshiko
authors: Y
authors: Atsuta
authors: Division of Hematology, Saitama Medical Center, Jichi Medical University, Saitama, Japan; Division of Hematology, Department of Medicine, Jichi Medical University, Tochigi, Japan. Electronic address: ycanda-tky@umin.ac.jp.
authors: Yoshinobu
authors: Y
authors: Kanda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005838:Genotype; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000276:immunology; D006680:HLA Antigens; D006239:Haplotypes; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D035781:Siblings; D016019:Survival Analysis; D014019:Tissue Donors; D000075442:Transplantation, Haploidentical; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D006680:HLA Antigens
keywords: Donor selection; GVHD; HLA mismatch; HLA-homozygous haplotypes; Host-versus-graft direction; Overall survival