title: Safety of blood group A2-to-O liver transplantation: an analysis of the United Network of Organ Sharing database.
abstract: BACKGROUND
  ABO-incompatible organ transplantation typically induces hyperacute rejection. A2-to-O liver transplantations have been successful. This study compared overall and graft survival in O recipients of A2 and O grafts based on Organ Procurement and Transplantation Network data.
  
  
  METHODS
  Scientific Registry of Transplant Recipients data were used. The first A2-to-O liver transplantation was entered on March 11, 1990; all previous transplantations were excluded. Between March 11, 1990, and September 3, 2010, 43,335 O recipients underwent transplanation, of whom 358 received A2 grafts.
  
  
  RESULTS
  There were no significant differences in age, sex, and race between the groups. Recipients of A2 grafts versus O grafts were significantly more likely to be hospitalized at transplantation (45% vs. 38%, P≤0.05) and to have a higher mean (SD) model for end-stage liver disease score (24 [11] vs. 22 [10], P≤0.05). 10% of A2 recipients and 9% of O recipients underwent retransplantation. No significant differences existed in rejection during the transplantation admission and at 12 months: 7% versus 6% and 20% versus 22% for A2 recipients and O recipients, respectively; and there were no significant differences in contributing factors to graft failure or cause of death. At 5 years, overall survival of A2 and O graft recipients was 77% and 74%, respectively (log rank=0.71). At 5 years, graft survival was 66% in both groups (log rank=0.52). Donor blood group was insignificant on Cox regression for overall and graft survival.
  
  
  CONCLUSIONS
  Using Organ Procurement and Transplantation Network/Scientific Registry of Transplant Recipients data, we present the largest series of A2-to-O liver transplantations and conclude this mismatch option to be safe with similar overall and graft survival. This opens possibilities to further meet the demands of a shrinking organ supply, especially with regard to expanding living-donor options.
authors.affiliation: Section of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, NewYork-Presbyterian Hospital/Weill Cornell Medical Center, New York, NY 10065, USA. mik9020@med.cornell.edu
authors.forename: Michael D
authors.initials: MD
authors.lastname: Kluger
authors.forename: James V
authors.initials: JV
authors.lastname: Guarrera
authors.forename: Sonja K
authors.initials: SK
authors.lastname: Olsen
authors.forename: Robert S
authors.initials: RS
authors.lastname: Brown
authors.forename: Jean C
authors.initials: JC
authors.lastname: Emond
authors.forename: Daniel
authors.initials: D
authors.lastname: Cherqui
mesh_terms: D000017:ABO Blood-Group System; D000293:Adolescent; D000328:Adult; D001787:Blood Group Incompatibility / Q000276:immunology* / Q000401:mortality; D001788:Blood Grouping and Crossmatching; D016009:Chi-Square Distribution; D002648:Child; D046148:Donor Selection; D005260:Female; D006084:Graft Rejection / Q000276:immunology; D006085:Graft Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D016031:Liver Transplantation / Q000276:immunology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014019:Tissue Donors / Q000600:supply & distribution*; D009927:Tissue and Organ Procurement; D016896:Treatment Outcome; D014481:United States
chemical_list: D000017:ABO Blood-Group System