Race/ethnicity is associated with ABO‐nonidentical liver transplantation in the United States

Abstract

United Network for Organ Sharing (UNOS) policies allow for ABO-nonidentical liver transplantation (LT) in candidates with Model for End-Stage Liver Disease (MELD) scores greater than 30. Previous studies showed ABO-nonidentical LT resulted in an 18% and 55% net gain in livers for B and AB candidates. These results suggested that the current liver ABO allocation policies may need refinement. There are, however, strong associations between ABO blood groups and race/ethnicity. We hypothesized that race/ethnicity is associated with ABO-nonidentical LT and that this is primarily influenced by recipient ABO status. We examined non-status 1 adult candidates registered between July 1, 2013, and December 31, 2015. There were 27 835 candidates (70% non-Hispanic White, 15% Hispanic, 9% Black, 4% Asian, 1% Other/Multiracial). A total of 11 369 underwent deceased donor LT: 93% ABO identical, 6% ABO compatible, and 1% ABO incompatible. Black and Asian race/ethnicity were associated with increased likelihoods of ABO-nonidentical LT. Adjustment for disease etiology, listing MELD, transplant center volume, and UNOS region did not alter this association. Stepwise inclusion of recipient ABO status did eliminate this significant association of race/ethnicity with ABO-nonidentical LT. Blacks and Asians may be advantaged by ABO-nonidentical LT, and we suspect that changes to the existing policies may disproportionately impact these groups.

A2 liver transplantation across the ABO barrier: Increasing options in the donor pool?

“…We recently conducted an analysis of ABO nonidentical liver transplantation using a more contemporary cohort of liver transplant recipients in the United States using data from the UNOS registry from 2013 to 2015. In this cohort, the vast majority (137/154 [87%]) of non‐status 1 ABO‐incompatible transplants were A2→O . Additional analyses of posttransplant survival rates demonstrated that the recipients of A2→O grafts had similar 1‐year survival rates (hazard ratio 1.11, 95% confidence interval 0.64‐1.92, P = 0.72) compared with recipients of O→O grafts in adjusted multivariable Cox models (Fig.…”

“…3). 8 This demonstrated that MELD score or relative donor scarcity is not the sole driver of A2!O transplantation, and that these differences may reflect center-level variations or protocols, which warrants further investigation.…”

“…In this cohort, the vast majority (137/154 [87%]) of nonstatus 1 ABO-incompatible transplants were A2!O. 8 Additional analyses of posttransplant survival rates demonstrated that the recipients of A2!O grafts had similar 1-year survival rates (hazard ratio 1.11, 95% confidence interval 0.64-1.92, P 5 0.72) compared with recipients of O!O grafts in adjusted multivariable Cox models (Fig. 2).…”

“…Most numbers of A2→O matching are taking place in regions 5 (23%), 2 (14%), 11 (13%), and 3 (10%); notably, these regions were neither the ones with the highest median MELD scores at transplantation, nor were they similar in the relative utilization of A2→O as a percentage of total O transplants (Fig. ) . This demonstrated that MELD score or relative donor scarcity is not the sole driver of A2→O transplantation, and that these differences may reflect center‐level variations or protocols, which warrants further investigation.…”

Receipt of a pediatric liver offer as the first offer reduces waitlist mortality for adult women

“…This delineation was used as UNOS allocation rules governing donors diverge at age 18 . Donor and waitlist candidate UNOS regions were categorized based on the median allocation MELD score at transplantation during the study period: “low” for regions with MELD <27, “medium” for regions with MELD ≥27 and <30, and “high” for regions with MELD ≥30 similar to the categorization used in a previous analysis …”