Department of Nephrology, University Hospital Regensburg, Regensburg, Germany.
Center for Clinical Studies, University Hospital Regensburg, Regensburg, Germany.
Transplantation. 2022 Dec 1;106(12):2448-2455. doi: 10.1097/TP.0000000000004238. Epub 2022 Aug 2.
Assignment of unacceptable HLA mismatches (UAMs) prevents transplantation of incompatible grafts but potentially prolongs waiting time. Whether this is true in the Eurotransplant Kidney Allocation System (ETKAS) and the Eurotransplant Senior Program in Germany is highly debated and relevant for UAM policies.
Donor pool restriction due to UAM was expressed as percent virtual panel-reactive antibodies (vPRAs). Kaplan-Meier estimates and multivariable Cox regression models were used to analyze the impact of vPRA levels on waiting time and transplant probability during a period of 2 y in all patients eligible for a kidney graft unter standard circumstances in Germany on February 1, 2019 (n = 6533). Utility of the mismatch probability score to compensate for sensitization in ETKAS was also investigated.
In ETKAS, donor pool restriction resulted in significant prolongation of waiting time and reduction in transplant probability only in patients with vPRA levels above 85%. This was most evident in patients with vPRA levels above 95%, whereas patients in the acceptable mismatch program had significantly shorter waiting times and higher chances for transplantation than nonsensitized patients. In the Eurotransplant Senior Program, vPRA levels above 50% resulted in significantly longer waiting times and markedly reduced the chance for transplantation. Compensation for sensitization by the mismatch probability score was insufficient.
Donor pool restriction had no significant impact on waiting time in most sensitized patients. However, despite the existence of the acceptable mismatch program, the majority of highly sensitized patients is currently disadvantaged and would benefit from better compensation mechanisms.
不匹配的 HLA 分配（UAM）会导致不相容的移植物移植受阻，但也可能延长等待时间。在 Eurotransplant 肾脏分配系统（ETKAS）和德国 Eurotransplant 高级项目中，这种情况是否属实存在很大争议，这对 UAM 政策具有重要意义。
由于 UAM，供体库限制表示为虚拟面板反应性抗体（vPRAs）的百分比。使用 Kaplan-Meier 估计和多变量 Cox 回归模型，分析了 2019 年 2 月 1 日在德国所有符合标准条件且有资格接受肾脏移植的患者（n=6533）中 vPRA 水平对等待时间和移植概率的影响。还研究了错配概率评分在 ETKAS 中补偿致敏作用的效用。
在 ETKAS 中，只有在 vPRA 水平高于 85%的患者中，供体库限制才会导致等待时间显著延长和移植概率降低。在 vPRA 水平高于 95%的患者中，这一点最为明显，而在可接受的错配方案中，患者的等待时间明显更短，移植机会也高于未致敏患者。在 Eurotransplant 高级项目中，vPRA 水平高于 50%会导致等待时间显著延长，并明显降低移植机会。错配概率评分对致敏的补偿作用不足。
在大多数致敏患者中，供体库限制对等待时间没有显著影响。然而，尽管存在可接受的错配方案，但大多数高度致敏的患者目前处于不利地位，需要更好的补偿机制。
