title: Double umbilical cord blood transplantation: a study of early engraftment kinetics in leukocyte subsets using HLA-specific monoclonal antibodies.
abstract: Single cord blood unit (CBU) predominance is usually established within the first month after double umbilical cord blood transplantation (UCBT). However, the kinetics of engraftment of the different leukocyte subsets and the mechanism of graft predominance is largely unknown. To investigate whether a differential engraftment might reveal a specific subset that could play a key role in the mechanism of graft predominance, we studied early engraftment kinetics of different leukocyte subpopulations by flow cytometry using human monoclonal antigen-specific human leukocyte antigen antibodies, directed against mismatched human leukocyte antigen-A or -B antigens between recipient and CBUs. Twenty-two patients, who had received a double UCBT preceded by a reduced-intensity conditioning regimen, were evaluated at days +11, +18, +25, and +32 posttransplantation. Single CBU predominance in the various leukocyte subsets was established within 18 days posttransplantation. CD4+ T cells of the dominant CBU showed early peripheral blood expansion. Moreover, chimerism in CD4+ and CD8+ T cell and natural killer cell subsets at day +11 was predictive of ultimate graft predominance. These findings show that engraftment kinetics of the various leukocyte subsets vary considerably after double UCBT and may suggest an important role for CD4+ T cells in a presumed alloreactive graft-versus-graft rejection.
authors.affiliation: JJ van Rood Center for Clinical Transfusion Research/Sanquin Blood Supply, Leiden, The Netherlands. judith.somers@sanquin.nl
authors.forename: Judith A E
authors.initials: JA
authors.lastname: Somers
authors.forename: Anneke
authors.initials: A
authors.lastname: Brand
authors.forename: Yvette
authors.initials: Y
authors.lastname: van Hensbergen
authors.forename: Arend
authors.initials: A
authors.lastname: Mulder
authors.forename: Machteld
authors.initials: M
authors.lastname: Oudshoorn
authors.forename: Kees
authors.initials: K
authors.lastname: Sintnicolaas
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Gratama
authors.forename: J H Frederik
authors.initials: JH
authors.lastname: Falkenburg
authors.forename: Eric
authors.initials: E
authors.lastname: Braakman
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Cornelissen
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use*; D046528:Chimerism; D036101:Cord Blood Stem Cell Transplantation / Q000379:methods*; D005260:Female; D006085:Graft Survival / Q000187:drug effects* / Q000276:immunology; D015234:HLA-A Antigens / Q000276:immunology*; D015235:HLA-B Antigens / Q000276:immunology*; D019337:Hematologic Neoplasms / Q000276:immunology / Q000601:surgery; D006801:Humans; D007962:Leukocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D015234:HLA-A Antigens; D015235:HLA-B Antigens