title: HLA match likelihoods for hematopoietic stem-cell grafts in the U.S. registry.
abstract: BACKGROUND
  Hematopoietic stem-cell transplantation (HSCT) is a potentially lifesaving therapy for several blood cancers and other diseases. For patients without a suitable related HLA-matched donor, unrelated-donor registries of adult volunteers and banked umbilical cord-blood units, such as the Be the Match Registry operated by the National Marrow Donor Program (NMDP), provide potential sources of donors. Our goal in the present study was to measure the likelihood of finding a suitable donor in the U.S. registry.
  
  
  METHODS
  Using human HLA data from the NMDP donor and cord-blood-unit registry, we built population-based genetic models for 21 U.S. racial and ethnic groups to predict the likelihood of identifying a suitable donor (either an adult donor or a cord-blood unit) for patients in each group. The models incorporated the degree of HLA matching, adult-donor availability (i.e., ability to donate), and cord-blood-unit cell dose.
  
  
  RESULTS
  Our models indicated that most candidates for HSCT will have a suitable (HLA-matched or minimally mismatched) adult donor. However, many patients will not have an optimal adult donor--that is, a donor who is matched at high resolution at HLA-A, HLA-B, HLA-C, and HLA-DRB1. The likelihood of finding an optimal donor varies among racial and ethnic groups, with the highest probability among whites of European descent, at 75%, and the lowest probability among blacks of South or Central American descent, at 16%. Likelihoods for other groups are intermediate. Few patients will have an optimal cord-blood unit--that is, one matched at the antigen level at HLA-A and HLA-B and matched at high resolution at HLA-DRB1. However, cord-blood units mismatched at one or two HLA loci are available for almost all patients younger than 20 years of age and for more than 80% of patients 20 years of age or older, regardless of racial and ethnic background.
  
  
  CONCLUSIONS
  Most patients likely to benefit from HSCT will have a donor. Public investment in donor recruitment and cord-blood banks has expanded access to HSCT. (Funded by the Office of Naval Research, Department of the Navy, and the Health Resources and Services Administration, Department of Health and Human Services.).
authors: From the National Marrow Donor Program/Be the Match, Minneapolis (L.G., E.W., J.F., D.C., M.M.); the Center for International Blood and Marrow Transplant Research, Milwaukee and Minneapolis (M.E., S.S., J.D.R., M.H.); and the Blood Stem Cell Transplantation Program, Division of Transplantation, Health Resources and Services Administration (R.B.), and the C.W. Bill Young Marrow Donor Recruitment and Research Program, Department of Defense Marrow Donor Recruitment and Research Program, Bone Marrow Research Directorate, Naval Medical Research Center, Department of the Navy (R.H.) - both in Washington, DC.
authors: Loren
authors: L
authors: Gragert
authors: Mary
authors: M
authors: Eapen
authors: Eric
authors: E
authors: Williams
authors: John
authors: J
authors: Freeman
authors: Stephen
authors: S
authors: Spellman
authors: Robert
authors: R
authors: Baitty
authors: Robert
authors: R
authors: Hartzman
authors: J Douglas
authors: JD
authors: Rizzo
authors: Mary
authors: M
authors: Horowitz
authors: Dennis
authors: D
authors: Confer
authors: Martin
authors: M
authors: Maiers
mesh_terms: D000328:Adult; D001771:Blood Banks; D001853:Bone Marrow; D005006:Ethnicity; D005312:Fetal Blood; D006680:HLA Antigens; D018380:Hematopoietic Stem Cell Transplantation; D006650:Histocompatibility Testing; D006801:Humans; D044469:Racial Groups; D012042:Registries; D014019:Tissue Donors / Q000600:supply & distribution; D014481:United States
chemical_list: D006680:HLA Antigens