title: HLA mismatch direction in cord blood transplantation: impact on outcome and implications for cord blood unit selection.
abstract: Donor-recipient human leukocyte antigen mismatch level affects the outcome of unrelated cord blood (CB) transplantation. To identify possible "permissive" mismatches, we examined the relationship between direction of human leukocyte antigen mismatch ("vector") and transplantation outcomes in 1202 recipients of single CB units from the New York Blood Center National Cord Blood Program treated in United States Centers from 1993-2006. Altogether, 98 donor/patient pairs had only unidirectional mismatches: 58 in the graft-versus-host (GVH) direction only (GVH-O) and 40 in the host-versus-graft or rejection direction only (R-O). Engraftment was faster in patients with GVH-O mismatches compared with those with 1 bidirectional mismatch (hazard ratio [HR] = 1.6, P = .003). In addition, patients with hematologic malignancies given GVH-O grafts had lower transplantation-related mortality (HR = 0.5, P = .062), overall mortality (HR = 0.5, P = .019), and treatment failure (HR = 0.5, P = .016), resulting in outcomes similar to those of matched CB grafts. In contrast, R-O mismatches had slower engraftment, higher graft failure, and higher relapse rates (HR = 2.4, P = .010). Based on our findings, CB search algorithms should be modified to identify unidirectional mismatches. We recommend that transplant centers give priority to GVH-O-mismatched units over other mismatches and avoid selecting R-O mismatches, if possible.
authors.affiliation: New York Blood Center, National Cord Blood Program, New York, NY, USA.
authors.forename: Cladd E
authors.initials: CE
authors.lastname: Stevens
authors.forename: Carmelita
authors.initials: C
authors.lastname: Carrier
authors.forename: Carol
authors.initials: C
authors.lastname: Carpenter
authors.forename: Dorothy
authors.initials: D
authors.lastname: Sung
authors.forename: Andromachi
authors.initials: A
authors.lastname: Scaradavou
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D036101:Cord Blood Stem Cell Transplantation / Q000379:methods* / Q000401:mortality; D005260:Female; D005312:Fetal Blood / Q000276:immunology* / Q000637:transplantation*; D006086:Graft vs Host Disease / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology*; D019337:Hematologic Neoplasms / Q000401:mortality / Q000601:surgery* / Q000628:therapy; D006650:Histocompatibility Testing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D006680:HLA Antigens