Effects Of Recipient Racial Disparity And Changes In Kidney Allocation Strategy On Kidney Transplant Outcomes

Recipient racial disparity can affect the outcomes of kidney transplant(KT).Previous studies have focused on differences in KT outcomes between white and black recipients,but little is known about differences in other racial recipients,such as Asian and Hispanic.Kidney allocation strategies inevitably have an impact on KT outcomes,and to improve the equity and utility of KT,a major restructuring of kidney allocation strategies in the United States occurred on December 4,2014,with the implementation of the Kidney Allocation System(KAS).KAS changes kidney allocation priority for some racial patients,and it remains unclear how this adjustment in kidney allocation strategy affects KT outcomes and whether it changes the impact of recipient racial disparity on KT outcomes.Analyzing differences in KT outcomes among multiple racial recipients(especially Asian recipients versus other racial groups)and analyzing the impact of changes in kidney allocation strategies on them will help us summarize advanced foreign experience to guide our clinical practice of domestic transplantation and develop relevant health policies.A retrospective analysis of KT data from the Organ Procurement Transplant Network/United Network for Organ Sharing(OPTN/UNOS)was conducted to compare outcomes among white,black,Hispanic,and Asian recipients who received their first kidney transplant over a 14-year period(December 4,2007,to December 3,2021).Outcomes,including graft failure,mortality,and death-censored graft survival,were compared among racial groups.To clarify the effects of KAS implementation on KT,we conducted a short-term(1 year),medium-term(3 years),and long-term(7 years)comparison using the KAS implementation date of December 4,2014 as the cut-off point to further analyze the impact of KAS on KT outcomes,numbers,and racial disparities.The results of this study showed that among the four racial groups,black recipients had the highest 5-year graft failure and mortality(26.70%and 16.20%,respectively),followed by white recipients(19.30% and15.00%,respectively),Hispanic recipients(18.50% and 13.10%,respectively),and Asian recipients(14.90% and 10.70%,respectively)(P<0.05).Asian recipients had the highest 5-year death-censored graft survival(93.00%),followed by white recipients(91.60%),Hispanic recipients(90.60%),and black recipients(83.40%)(P<0.05).After adjusting for confounders,the risk of graft failure and mortality was highest among white recipients,followed by black recipients(adjusted hazard ratio [a HR],0.96 [0.94–0.98];a HR,0.76 [0.74–0.78],respectively),Hispanic recipients(a HR,0.74 [0.72–0.76];a HR,0.67 [0.65–0.69],respectively),Asian recipients(a HR,0.64 [0.61–0.67];a HR,0.57[0.54–0.60],respectively)(all with white recipients as reference).Compared to 1 year prior to KAS implementation,the overall risk of graft failure was reduced by 18% 1 year after KAS implementation(a HR,0.82 [0.78–0.85]).Compared to 3 years prior to KAS implementation,the overall risk of graft failure was reduced by 4%(a HR,0.96 [0.93–0.99])and the overall risk of mortality was increased by 18%(a HR,1.18[1.13–1.22])in the 3 years after KAS implementation.Compared to the 7years prior to KAS implementation,the overall risk of graft failure and mortality increased by 12% and 48% in the 7 years after KAS implementation(a HR,1.12 [1.09–1.15];a HR,1.48 [1.44–1.52],respectively).Prior to KAS,there was a decreasing trend in the number of KT among white recipients(-73.40 cases/year),while the number of KT among black,Hispanic,and Asian recipients all showed a slow increase(1.30,45.40,and 32.40 cases/year for black,Hispanic,and Asian recipients,respectively).The number of KT increased significantly for all four racial recipients after KAS implementation(366.50,297.70,244.90,and 91.10cases/year for white,black,Hispanic,and Asian recipients,respectively).7 Years prior to KAS implementation,using white recipients as a reference,Asian recipients had a 41.00% and 49.00% lower risk of graft failure and mortality,respectively(a HR,0.59 [0.55–0.64];a HR,0.51[0.47–0.56]);Hispanic recipients had a 31.00% and 42.00% lower risk of graft failure and mortality,respectively(a HR,0.69 [0.66–0.73];a HR,0.58[0.55–0.62]);Black recipients had a 4.00% and 30.00% lower risk of graft failure and mortality,respectively(a HR,0.96 [0.93–0.99];a HR,0.70[0.67–0.73]).7 Years after KAS implementation,using white recipients as a reference,Asian recipients had a 35.00% and 41.00% lower risk of graft failure and mortality,respectively(a HR,0.65 [0.60–0.70];a HR,0.59[0.54–0.65]);Hispanic recipients had a 22.00% and 25.00% lower risk of graft failure and mortality,respectively(a HR,0.78 [0.74–0.82];a HR,0.75[0.71–0.79]);Black recipients had an 18.00% lower risk of mortality(a HR,0.82 [0.78–0.86]).In summary,racial disparities in recipients significantly affected KT outcomes,with Asian recipients having a significantly better outcomes than other racial recipients.KAS enhanced equity in kidney allocation,reduced racial disparities in KT numbers and outcomes,and improved short-term prognosis of KT recipients,but was detrimental to long-term prognosis.The kidney allocation strategy requires further optimization in the development of relevant health policies at a later stage.