title: Impact of total body irradiation on successful neutrophil engraftment in unrelated bone marrow or cord blood transplantation.
abstract: Total body irradiation (TBI) has been thought to promote donor cell engraftment in allogeneic hematopoietic cell transplantation (HCT) from alternative donors. However, recent progress in HCT strategies may affect the clinical significance of TBI on neutrophil engraftment. With the use of a Japanese transplant registry database, we analyzed 3933 adult recipients (>15 y.o.) who underwent HCT between 2006 and 2013 from an 8/8 HLA-matched unrelated bone marrow donor (MUD, n = 1367), an HLA-mismatched unrelated bone marrow donor (MMUD, n = 1102), or unrelated cord blood (CBT, n = 1464). Conditioning regimens were divided into five groups: High-TBI-(>8Gy), Low-TBI- (≤8Gy), and no-TBI-myeloablative conditioning (MAC), and Low-TBI- and no-TBI-reduced-intensity conditioning (RIC). In both MUD and MMUD, neutrophil engraftment rate was >90% in each of the five conditioning groups, and TBI was not associated with prompt neutrophil engraftment in multivariate analyses. Conversely, in CBT, TBI regimens had a higher rate of day-30 neutrophil engraftment than no-TBI-regimens: 78% in High-TBI-MAC, 83% in Low-TBI-MAC, and 76% in Low-TBI-RIC versus 65% in No-TBI-MAC, and 68% in No-TBI-RIC (P < .001). Multivariate analyses in CBT demonstrated that TBI-regimens were significantly associated with a higher rate of neutrophil engraftment. Subsequently focusing on CBT patients alone, TBI-regimens were significantly associated with a higher rate of neutrophil engraftment in patients who received CBT with a 4/6 or less HLA allele-match, or who had anti-HLA antibodies. In summary, TBI-regimens had no impact on neutrophil engraftment in the current practice of unrelated bone marrow transplantation. However, in CBT, TBI is still necessary to enhance engraftment.
authors.affiliation: Division of Hematology, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakasone
authors.affiliation: Department of Hematopoietic Stem Cell Transplantation, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Fuji
authors.affiliation: Department of Medical Oncology and Hematology, Kobe University Hospital, Kobe, Japan.
authors.forename: Kimikazu
authors.initials: K
authors.lastname: Yakushijin
authors.affiliation: Department of Hematology and Oncology, Tokai University School of Medicine, Isehara, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Onizuka
authors.affiliation: Department of Hematology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Shinohara
authors.affiliation: Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan.
authors.forename: Kazuteru
authors.initials: K
authors.lastname: Ohashi
authors.affiliation: Department of Hematology, Japanese Red Cross Nagoya First Hospital, Nagoya, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Miyamura
authors.affiliation: Department of Hematology, Toranomon Hospital, Tokyo, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Uchida
authors.affiliation: Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan.
authors.forename: Minoko
authors.initials: M
authors.lastname: Takanashi
authors.affiliation: Department of Hematology and Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Ichinohe
authors.affiliation: Japanese Data Center for Hematopoietic Cell Transplantation, Nagoya, Japan.|Department of Healthcare Administration, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Atsuta
authors.affiliation: Department of Hematopoietic Stem Cell Transplantation, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fukuda
authors.affiliation: Department of Medical Oncology and Hematology, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Ogata
mesh_terms: D000293:Adolescent; D000328:Adult; D001853:Bone Marrow / Q000276:immunology*; D036101:Cord Blood Stem Cell Transplantation / Q000379:methods*; D005260:Female; D006648:Histocompatibility / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007938:Leukemia / Q000401:mortality / Q000532:radiotherapy / Q000628:therapy*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology / Q000276:immunology / Q000528:radiation effects; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016019:Survival Analysis; D014019:Tissue Donors; D019172:Transplantation Conditioning / Q000379:methods*; D014916:Whole-Body Irradiation / Q000379:methods*; D055815:Young Adult