Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania.
Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.
J Am Soc Nephrol. 2023 Jan 1;34(1):26-39. doi: 10.1681/ASN.2022040471. Epub 2022 Oct 27.
In March 2021, the United States implemented a new kidney allocation system (KAS250) for deceased donor kidney transplantation (DDKT), which eliminated the donation service area-based allocation and replaced it with a system on the basis of distance from donor hospital to transplant center within/outside a radius of 250 nautical miles. The effect of this policy on kidney discards and logistics is unknown.
We examined discards, donor-recipient characteristics, cold ischemia time (CIT), and delayed graft function (DGF) during the first 9 months of KAS250 compared with a pre-KAS250 cohort from the preceding 2 years. Changes in discards and CIT after the onset of COVID-19 and the implementation of KAS250 were evaluated using an interrupted time-series model. Changes in allocation practices (biopsy, machine perfusion, and virtual cross-match) were also evaluated.
Post-KAS250 saw a two-fold increase in kidneys imported from nonlocal organ procurement organizations (OPO) and a higher proportion of recipients with calculated panel reactive antibody (cPRA) 81%-98% (12% versus 8%; P <0.001) and those with >5 years of pretransplant dialysis (35% versus 33%; P <0.001). CIT increased (mean 2 hours), including among local OPO kidneys. DGF was similar on adjusted analysis. Discards after KAS250 did not immediately change, but we observed a statistically significant increase over time that was independent of donor quality. Machine perfusion use decreased, whereas reliance on virtual cross-match increased, which was associated with shorter CIT.
Early trends after KAS250 show an increase in transplant access to patients with cPRA>80% and those with longer dialysis duration, but this was accompanied by an increase in CIT and a suggestion of worsening kidney discards.
2021 年 3 月，美国实施了一种新的肾移植分配系统（KAS250），用于已故供体肾移植（DDKT），该系统取消了以捐赠服务区域为基础的分配方式，代之以基于供体医院到移植中心的距离的系统，距离在 250 海里半径内/外。该政策对肾脏废弃和物流的影响尚不清楚。
我们比较了 KAS250 实施前后的 9 个月内的废弃率、供者-受者特征、冷缺血时间（CIT）和延迟移植物功能（DGF），并与前 2 年的 KAS250 前队列进行了比较。使用中断时间序列模型评估了 COVID-19 发病和 KAS250 实施后废弃率和 CIT 的变化。还评估了分配实践（活检、机器灌注和虚拟交叉匹配）的变化。
KAS250 后，来自非本地器官采购组织（OPO）的进口肾脏增加了两倍，cPRA 为 81%-98%的受者比例（12%比 8%；P <0.001）和透析时间>5 年的受者比例（35%比 33%；P <0.001）更高。CIT 增加（平均增加 2 小时），包括本地 OPO 肾脏。调整分析后 DGF 相似。KAS250 后废弃率没有立即改变，但我们观察到随着时间的推移，废弃率呈上升趋势，这与供体质量无关。机器灌注的使用减少，而对虚拟交叉匹配的依赖增加，这与 CIT 缩短有关。
KAS250 后的早期趋势表明，具有 cPRA>80%和透析时间较长的患者的移植机会增加，但这伴随着 CIT 的增加和肾脏废弃率恶化的迹象。
