title: Quantitation of hematogones at the time of engraftment is a useful prognostic indicator in allogeneic hematopoietic stem cell transplantation.
abstract: Transient marrow expansion of normal B-cell precursors, termed hematogones, is occasionally observed after hematopoietic stem cell transplantation (HSCT). To understand the clinical significance of this phenomenon, we enumerated hematogones in 108 consecutive patients who received allogeneic HSCT for the treatment of hematologic malignancies, including acute myelogenous leukemia, advanced myelodysplastic syndromes, acute lymphoblastic leukemia, and non-Hodgkin lymphoma. Hematogone quantitation was performed at the time of complete donor engraftment (median day 25 and 32 in patients who received bone marrow and cord blood cell transplants, respectively). Hematogones were polyclonal B cells, and their frequencies correlated positively with blood B-cell numbers, and inversely with donors’ but not recipients' age, suggesting that hematogones reflect cell-intrinsic B-cell potential of donor cells. Interestingly, patients developing hematogones that comprised > 5% of bone marrow mononuclear cells constituted a group with significantly prolonged overall survival and relapse-free survival, irrespective of their primary disease or donor cell source. In addition, patients with > 5% hematogones developed severe acute graft-versus-host diseases less frequently, which may contribute toward their improved survival. We therefore conclude that the amount of hematogones at the time of engraftment may be a useful tool in predicting the prognosis of patients treated with allogeneic HSCT.
  
  
  CONCLUSIONS
  Quantitation of hematogones at engraftment is useful to predict prognosis of patients treated with allogeneic stem cell transplantation.
authors.affiliation: Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University Graduate School of Medicine, Fukuoka, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shima
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Yoshikane
authors.initials: Y
authors.lastname: Kikushige
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Mori
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kamezaki
authors.forename: Ken
authors.initials: K
authors.lastname: Takase
authors.forename: Hideho
authors.initials: H
authors.lastname: Henzan
authors.forename: Akihiko
authors.initials: A
authors.lastname: Numata
authors.forename: Yoshikiyo
authors.initials: Y
authors.lastname: Ito
authors.forename: Katsuto
authors.initials: K
authors.lastname: Takenaka
authors.forename: Hiromi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kamimura
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Eto
authors.forename: Koji
authors.initials: K
authors.lastname: Nagafuji
authors.forename: Takanori
authors.initials: T
authors.lastname: Teshima
authors.forename: Koji
authors.initials: K
authors.lastname: Kato
authors.forename: Koichi
authors.initials: K
authors.lastname: Akashi
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D016026:Bone Marrow Transplantation; D036101:Cord Blood Stem Cell Transplantation; D018572:Disease-Free Survival; D005260:Female; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000097:blood / Q000401:mortality / Q000628:therapy; D019337:Hematologic Neoplasms / Q000097:blood / Q000401:mortality / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D054448:Precursor Cells, B-Lymphoid; D015996:Survival Rate; D014184:Transplantation, Homologous; D061349:Unrelated Donors