TRANSPLANTATION AND CELLULAR ENGINEERING
Unrelated donor choices for allogeneic hematopoietic cell
transplantation in Canada: an evaluation of factors influencing
Robert S. Liwski,
and David S. Allan
Utilization of unrelated donors and
cord blood units (CBUs) for allogeneic hematopoietic cell
transplantation continues to increase. Understanding the
practices of donor selection by transplant centers is
critical for unrelated donor registries and cord blood
banks to optimize registry composition and inventory to
meet patient need.
STUDY DESIGN AND METHODS:
and CBU selection practices of Canadian transplant
centers served by Canadian Blood Services’ OneMatch
Stem Cell & Marrow Network (OM) were reviewed,
including HLA match level, locus of disparity, age, sex,
and product choice (donor vs. CBU).
HLA-matched donors within OM and/or
international (INT) registries were preferentially
investigated, underscoring the primary importance of
HLA matching. In the case of HLA-mismatched donors,
HLA-A disparities were most common while DRB1
mismatches were least common. Advanced age, sex,
and lack of donor availability were the most frequent
reasons that high-probability OM donors were overlooked
in favor of INT donors. High-probability 10 of 10 HLA-
matched female donors from OM were often avoided in
favor of INT male donors. Use of female donors,
however, increased in cases restricted to more HLA-
disparate donor options. Caucasian patients were more
likely to find 10 of 10 matched donors, whereas use of
mismatched donors and CBUs were more prevalent
among non-Caucasian patients.
Recruitment and retention of young,
male donors from diverse ethnic backgrounds may
increase the usage of histocompatible OM donors for
patients in need.
ncreasing numbers of patients are deemed eligible
for hematopoietic cell transplantation, including
older patients with comorbidities, due to improved
supportive care and the introduction of reduced-
intensity conditioning regimens. Moreover, evolving indi-
cations for allogeneic transplant include acute myeloid
leukemia at earlier stages of disease, myelodysplastic syn-
drome, and myeloproliferative disorders.
As the number
of available sibling donors declines due to smaller family
size in recent decades
and potential issues related to
donor eligibility in older siblings, transplant centers con-
tinue to rely heavily on unrelated donors and cord blood
units (CBUs). Canadian transplant centers typically prefer
allele matching of prospective donors at HLA-A, -B, -C, -
ABBREVIATIONS: BM 5 marrow; CBB(s) 5 cord blood
bank(s); CBU(s) 5 cord blood unit(s); DLI(s) 5 donor
lymphocyte infusion(s); INT 5 international; OM 5
OneMatch; PBSC(s) 5 peripheral blood stem/progenitor
cell(s); TNC 5 total nucleated cell count.
OneMatch Stem Cell & Marrow Network, Canadian
Blood Services; the
Centre for Transfusion Research; the
Ottawa Hospital Research Institute, and the
Medicine, University of Ottawa, Ottawa, Ontario, Canada;
University Health Network, Toronto, Ontario, Canada; the
Departments of Pathology and Microbiology & Immunology,
Dalhousie University, Halifax, Nova Scotia, Canada.
Address reprint requests to: Dr David Allan, MD, FRCPC,
c/o The Ottawa Hospital, 501 Smyth Road, Box 704, Ottawa,
ON, Canada K1H 8L6; e-mail: email@example.com.
VGS and JK have contributed equally to this work.
JK was supported by the Centre for Transfusion Research
at The Ottawa Hospital and DSA is supported by the Depart-
ment of Medicine at the University of Ottawa.
Received for publication August 4, 2017; revision received
October 20, 2017; and accepted October 24, 2017.
718 TRANSFUSION Volume 58, March 2018