First Report on the OPTN National Variance: Allocation of A2 /A2 B Deceased Donor Kidneys to Blood Group B Increases Minority Transplantation

Am J Transplant. 2015 Dec;15(12):3134-42. doi: 10.1111/ajt.13409. Epub 2015 Aug 4.


In 2002, the Organ Procurement and Transplantation Network (OPTN) Minority Affairs Committee (MAC) implemented a national, prospective, "variance of practice" to allow deceased donor, ABO blood group incompatible, A2 antigen, kidney transplantation into blood group B recipients; outcomes of this cohort were compared to ABO compatible recipients. The goal of the variance was to increase the number of transplants to B candidates without negatively impacting survival or compromising system equity. Only B recipients with low anti-A IgG titers (<1:8) were eligible to receive these kidneys. Across eight participating Donation Service Areas (DSA), there were 101 A2 /A2 B to B transplants through 12/31/11, of which the majority of the recipients (61%) were ethnic minorities. At 12, 24, and 36 months, Kaplan-Meier graft survival rates for the B recipients of A2 /A2 B kidneys were 95.0%, 90.6%, and 85.4%, respectively, comparable to outcomes for B recipients of B kidneys, 92.6%, 87.9%, and 82.5%, respectively (p-value = 0.48). Five DSAs increased the proportion of B transplants during 41 months postvariance, with a lesser proportional decrease in blood group A transplants. The data support the proposition that this allocation algorithm may provide a robust mechanism to increase access of blood group B minority candidates to kidney transplantation.

Keywords: Organ Procurement and Transplantation Network (OPTN); United Network for Organ Sharing (UNOS); health services and outcomes research; kidney transplantation/nephrology; organ procurement and allocation; recipient selection; waitlist management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / immunology*
  • Adolescent
  • Adult
  • Aged
  • Blood Group Incompatibility / immunology*
  • Cadaver
  • Child
  • Child, Preschool
  • Ethnic Groups
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Infant, Newborn
  • Isoantibodies / immunology*
  • Kidney Transplantation*
  • Male
  • Middle Aged
  • Minority Groups
  • Prognosis
  • Resource Allocation*
  • Survival Rate
  • Tissue Donors
  • Tissue and Organ Procurement / organization & administration*
  • Tissue and Organ Procurement / statistics & numerical data
  • Young Adult


  • ABO Blood-Group System
  • Isoantibodies