title: HLA mismatching within or outside of cross-reactive groups (CREGs) is associated with similar outcomes after unrelated hematopoietic stem cell transplantation.
abstract: The National Marrow Donor Program maintains a registry of volunteer donors for patients in need of a hematopoietic stem cell transplantation. Strategies for selecting a partially HLA-mismatched donor vary when a full match cannot be identified. Some transplantation centers limit the selection of mismatched donors to those sharing mismatched antigens within HLA-A and HLA-B cross-reactive groups (CREGs). To assess whether an HLA mismatch within a CREG group ("minor") may result in better outcome than a mismatch outside CREG groups ("major"), we analyzed validated outcomes data from 2709 bone marrow and peripheral blood stem cell transplantations. Three-hundred and ninety-six pairs (15%) were HLA-DRB1 allele matched but had an antigen-level mismatch at HLA-A or HLA-B. Univariate and multivariate analyses of engraftment, graft-versus-host disease, and survival showed that outcome is not significantly different between minor and major mismatches (P = .47, from the log-rank test for Kaplan-Meier survival). However, HLA-A, HLA-B, and HLA-DRB1 allele-matched cases had significantly better outcome than mismatched cases (P < .001). For patients without an HLA match, the selection of a CREG-compatible donor as tested does not improve outcome.
authors.affiliation: Department of Surgery, University of Toronto, Ontario, Canada.
authors.forename: Judith A
authors.initials: JA
authors.lastname: Wade
authors.forename: Carolyn Katovich
authors.initials: CK
authors.lastname: Hurley
authors.forename: Steven K
authors.initials: SK
authors.lastname: Takemoto
authors.forename: John
authors.initials: J
authors.lastname: Thompson
authors.forename: Stella M
authors.initials: SM
authors.lastname: Davies
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Fuller
authors.forename: Glenn
authors.initials: G
authors.lastname: Rodey
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Confer
authors.forename: Harriet
authors.initials: H
authors.lastname: Noreen
authors.forename: Michael
authors.initials: M
authors.lastname: Haagenson
authors.forename: Fangyu
authors.initials: F
authors.lastname: Kan
authors.forename: John
authors.initials: J
authors.lastname: Klein
authors.forename: Mary
authors.initials: M
authors.lastname: Eapen
authors.forename: Stephen
authors.initials: S
authors.lastname: Spellman
authors.forename: Craig
authors.initials: C
authors.lastname: Kollman
mesh_terms: D000483:Alleles; D003430:Cross-Sectional Studies; D018572:Disease-Free Survival; D005260:Female; D006086:Graft vs Host Disease / Q000209:etiology / Q000401:mortality; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D019337:Hematologic Neoplasms / Q000150:complications / Q000401:mortality* / Q000628:therapy*; D018380:Hematopoietic Stem Cell Transplantation; D006650:Histocompatibility Testing; D006801:Humans; D019520:Living Donors; D008297:Male; D036102:Peripheral Blood Stem Cell Transplantation; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains