Impact of the new kidney allocation system A2/A2B → B policy on access to transplantation among minority candidates

Blood group B candidates, many of whom represent ethnic minorities, have historically had diminished access to deceased donor kidney transplantation (DDKT). The new national kidney allocation system (KAS) preferentially allocates blood group A2/A2B deceased donor kidneys to B recipients to address this ethnic and blood group disparity. No study has yet examined the impact of KAS on A2 incompatible (A2i) DDKT for blood group B recipients overall or among minorities. A case-control study of adult blood group B DDKT recipients from 2013 to 2017 was performed, as reported to the Scientific Registry of Transplant Recipients. Cases were defined as recipients of A2/A2B kidneys, whereas controls were all remaining recipients of non-A2/A2B kidneys. A2i DDKT trends were compared from the pre-KAS (1/1/2013-12/3/2014) to the post-KAS period (12/4/2014-2/28/2017) using multivariable logistic regression. Post-KAS, there was a 4.9-fold increase in the likelihood of A2i DDKT, compared to the pre-KAS period (odds ratio [OR] 4.92, 95% confidence interval [CI] 3.67-6.60). However, compared to whites, there was no difference in the likelihood of A2i DDKT among minorities post-KAS. Although KAS resulted in increasing A2/A2B→B DDKT, the likelihood of A2i DDKT among minorities, relative to whites, was not improved. Further discussion regarding A2/A2B→B policy revisions aiming to improve DDKT access for minorities is warranted.