Racial Differences in HLA Mismatch Potential Among Kidney Registrations
1UNOS, Richmond, VA, 2Surgery, Keck Medicine of USC, Los Angeles, CA, 3Carolinas Medical Center, Charlotte, NC, 4LifeLink Foundation Transplant Immunology Lab, Tampa, FL, 5Southwest Immunodiagnostics, Inc., San Antonio, TX, 6Beth Israel Deaconess Med Ctr, Boston, MA
Meeting: 2022 American Transplant Congress
Abstract number: 1754
Keywords: Allocation, HLA antigens, Kidney
Topic: Clinical Science » Kidney » 50 - Health Equity and Access
Session Information
Session Time: 7:00pm-8:00pm
Presentation Time: 7:00pm-8:00pm
Location: Hynes Halls C & D
*Purpose: HLA matched kidneys are associated with better long-term post-transplant graft survival. However, prioritizing patients well-matched with an available donor has historically resulted in disparities in access to transplant for racial/ethnic minorities. Our goal was to see, given a pool of donors, whether registrations (regs) of certain ethnicities were more likely to be a 0 HLA mismatch (MM) than others.
*Methods: We queried the OPTN database for deceased donors recovered 2011-2020 and kidney regs waiting on 10/31/21. Records with missing HLA typings were excluded (1.2% of donors and 0.1% of regs). We determined the proportion of donors with which each reg was a 0 DR or 0 ABDR MM. Mean percent of 0 DR and 0 ABDR MM was calculated overall and within race/ethnicity group, and 95% confidence intervals were obtained through bootstrapping regs (N = 1000).
*Results: There were 96,452 deceased donors recovered 2011-2021 and 97,531 kidney regs on the waiting list on 10/31/21. On average, kidney regs were 0 ABDR MM with 0.038% of donors. White regs had the highest rate of 0 ABDR MM (0.074%), 6x higher than Black (0.013%), 3x higher than Hispanic (0.028%), 9x higher than Asian (0.008%), and 3x higher than other race/ethnicity (0.029%) regs. On average, regs were 0 DR MM with 4.1% of donors. White regs had the highest rate of 0 DR MM (4.7%), 1.3x higher than Black (3.6%), 1.1x higher than Hispanic (4.2%), 1.3x higher than Asian (3.5%), and 1.3x higher than other race/ethnicity (3.6%) regs.
*Conclusions: White regs were significantly more likely to be 0 ABDR MM with a donor than regs of other race/ethnicity groups. 0 DR MM was more common overall, and White regs had the highest rate of 0 DR MM, but racial differences were far less pronounced. The OPTN Kidney Transplantation Committee is examining the prioritization of HLA MM in allocation as they develop a continuous distribution system. The weight of HLA MM in such a system will need to be examined to reduce racial disparities while optimizing graft survival.
To cite this abstract in AMA style:
Robinson A, Lindblad K, Stewart D, Kim J, Casingal V, Lalli P, Lunz J, Murphey C, Pavlakis M. Racial Differences in HLA Mismatch Potential Among Kidney Registrations [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/racial-differences-in-hla-mismatch-potential-among-kidney-registrations/. Accessed May 6, 2025.« Back to 2022 American Transplant Congress