title: Influence of conditioning regimens and stem cell sources on donor-type chimerism early after stem cell transplantation.
abstract: We retrospectively analyzed very early chimerism before and ongoing neutrophil engraftment (days 7, 14, 21, 28) and investigated the influence of conditioning regimens and stem cell sources on donor-type chimerism in 59 Japanese patients who had received allogeneic hematopoietic stem cell transplantation. The percentage of donor-type chimerism increased before engraftment in all patients who achieved engraftment. The average percentage of donor-type chimerism in patients who had received reduced-intensity stem cell transplantation (RIST) with total body irradiation (TBI) was significantly higher than that in patients who had received RIST without TBI (98.8% vs 87.5% on day 21, P<0.01; 99.3% vs 84.3% on day 28, P<0.01). The average percentage of donor-type chimerism after peripheral blood stem cell transplantation was significantly higher than that after bone marrow transplantation on day 7 (81.5% vs 43.1%, P<0.01), and the average percentage of donor-type chimerism after cord blood transplantation was significantly lower on day 14 (55.8% vs 84.8%, P<0.05). Compared with the average percentage of donor-type chimerism in patients who achieved engraftment with each stem cell source, a notable decrease in donor-type chimerism was observed in patients who failed to achieve engraftment. This study suggests that differences in conditioning regimens and stem cell sources should be taken into account when considering donor-type chimerism.
authors.affiliation: Department of Hematology and Oncology, Hokkaido University Graduate School of Medicine, N15 W7, Kita-Ku, Sapporo, 060-8638, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Sugita
authors.forename: Junji
authors.initials: J
authors.lastname: Tanaka
authors.forename: Aya
authors.initials: A
authors.lastname: Hashimoto
authors.forename: Souichi
authors.initials: S
authors.lastname: Shiratori
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yasumoto
authors.forename: Kentaro
authors.initials: K
authors.lastname: Wakasa
authors.forename: Misato
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Akio
authors.initials: A
authors.lastname: Shigematsu
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miura
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Masahiro
authors.initials: M
authors.lastname: Asaka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Imamura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016026:Bone Marrow Transplantation; D003131:Combined Modality Therapy; D033001:Directed Tissue Donation; D005260:Female; D006085:Graft Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D019653:Myeloablative Agonists / Q000627:therapeutic use; D009504:Neutrophils / Q000502:physiology*; D012189:Retrospective Studies; D033581:Stem Cell Transplantation; D018183:Transplantation Chimera; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous; D014916:Whole-Body Irradiation
chemical_list: D019653:Myeloablative Agonists