Assessing the impact of the new kidney allocation system on rates of transplantation for highly sensitized recipients – Center specific data

Abstract

Background The new OPTN/UNOS kidney allocation system (KAS) is designed to expand donor access for highly-HLA sensitized patients (HS). Our approach to transplanting the HS patients (PTS) awaiting deceased donor (DD) transplants (TXP) is to assign unacceptable antigens (UA) based on 4 antibody testing methods and to desensitize PTS using high dose IVIG and Rituximab. In the past, we would assign priority based on wait time and likelihood of receiving DD offers. Aim The aim of our study was to assess the impact of the new KAS on TXP rates for PTS with varying levels of sensitization compared to non-sensitized PTS. We examined PTS who are HS (99/100CPRA), moderately sensitized (80–98 CPRA) and less sensitized ( 20CPRA). Methods UAs are assigned based on 4 methods luminex single antigen with and without dilution, C1Q assay and CDC. Final crossmatches are performed by Flow and CDC. Patient’s antibody history, CPRA and crossmatch results were tabulated for this study. Rates of deceased donor TXP for a period of 144 days prior to and after December 7, 2014 were analyzed. Results The rate of transplantation for PTS in the 99–100% CPRA group was the same in both time periods. The number of deceased donor TXP in the 80–98% and 20–79% CPRA groups was reduced by 50%. However the number of TXP for PTS in 0–19% CPRA was increased by 50%. Conclusions While the rate of deceased donor TXP for PTS in 99–100% CPRA at our center remained the same at ∼ 12.7%, it increased from 2.5% to 17.7% for the national average. The new KAS appears to reduce the chance of transplantation for moderately sensitized recipients and increases the number of TXP for non-sensitized recipients at our center. The KAS appears to have little impact on transplanting the highly sensitized PTS at a center with progressive assignment of UAs and a desensitization program. Download : Download full-size image