title: Umbilical cord blood produces small megakaryocytes after transplantation.
abstract: Delayed platelet engraftment is a major complication of umbilical cord blood (CB) transplantation. Megakaryocytes derived from CB in vitro are smaller than megakaryocytes derived from bone marrow (BM) or mobilized peripheral blood from adults. Small megakaryocyte size may contribute to delayed platelet engraftment. To test whether small size persists after transplantation, we measured megakaryocyte size, concentration, and maturational stage in BM biopsy specimens obtained after transplantation in archived BM samples from patients receiving CB (CB group, n = 10) versus mobilized peripheral blood or BM transplantation (BM group, n = 9). Megakaryocytes in the postengraftment BM samples were significantly smaller in the CB group than in the BM group (median diameter, 16.7 vs 22.0 microm). There were no significant differences in megakaryocyte concentration or maturational stage between the CB and BM groups. For the first time, we demonstrate that the attainment of adult size in CB-derived megakaryocytes is delayed after human CB transplantation.
authors.affiliation: Department of Pediatrics, University of Florida, Gainesville, Florida, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Ignatz
authors.forename: Martha
authors.initials: M
authors.lastname: Sola-Visner
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Rimsza
authors.forename: Debra
authors.initials: D
authors.lastname: Fuchs
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Shuster
authors.forename: Xiao-Miao
authors.initials: XM
authors.lastname: Li
authors.forename: Anil
authors.initials: A
authors.lastname: Jotwani
authors.forename: Susan
authors.initials: S
authors.lastname: Staba
authors.forename: John R
authors.initials: JR
authors.lastname: Wingard
authors.forename: Zhongbo
authors.initials: Z
authors.lastname: Hu
authors.forename: William B
authors.initials: WB
authors.lastname: Slayton
mesh_terms: D000293:Adolescent; D016026:Bone Marrow Transplantation; D048429:Cell Size; D002648:Child; D002675:Child, Preschool; D036101:Cord Blood Stem Cell Transplantation / Q000009:adverse effects*; D051799:Delayed Graft Function / Q000097:blood; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology* / Q000637:transplantation*; D036102:Peripheral Blood Stem Cell Transplantation; D010976:Platelet Count; D013921:Thrombocytopenia / Q000097:blood