Ziemann Malte, Heßler Nicole, König Inke R, Lachmann Nils, Dick Andrea, Ditt Vanessa, Budde Klemens, Reinke Petra, Eisenberger Ute, Suwelack Barbara, Klein Thomas, Westhoff Timm H, Arns Wolfgang, Ivens Katrin, Habicht Antje, Renders Lutz, Stippel Dirk, Bös Dominik, Sommer Florian, Görg Siegfried, Nitschke Martin, Feldkamp Thorsten, Heinemann Falko M, Kelsch Reinhard
Institute of Transfusion Medicine, University Hospital of Schleswig-Holstein, Ratzeburger Allee 160, 23538?Lübeck, Germany.
Institute of Medical Biometry and Statistics, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany.
Nephrol Dial Transplant. 2017 May 1;32(5):880-889. doi: 10.1093/ndt/gfw462.
The assignment of human leucocyte antigens (HLAs) against which antibodies are detected as unacceptable antigens (UAGs) avoids allocation of HLA- incompatible allografts. There is uncertainty as to what extent UAGs decrease the probability of receiving a kidney offer.
Kidney transplantations in 3264 patients on the waiting lists of six German transplant centres were evaluated for a period of at least 2 years. The proportion of excluded offers due to UAGs was calculated as virtual panel-reactive antibodies (vPRAs).
In the common Eurotransplant Kidney Allocation Scheme, the transplant probability was unaffected by vPRAs in exploratory univariate analyses. In the multivariable model, a 1% increase in vPRA values was outweighed by an additional waiting time of 2.5 weeks. The model was confirmed using an external validation cohort of 1521 patients from seven centres. If only patients with standard risk were considered (e.g. no simultaneous transplantation of other organs), only 1.3 weeks additional waiting time was needed. In the Eurotransplant Senior Program, patients with vPRA values >50% had a strongly reduced transplant probability in the unadjusted analyses. In the multivariable model, a 1% increase in vPRA values was outweighed by an additional waiting time of 5 weeks.
This study demonstrates that the assignment of UAGs decreases the transplant probability in both main Eurotransplant allocation programs because of insufficient compensatory mechanisms. At present, for immunized patients, a prolonged waiting time has to be weighed against the increased immunologic risk due to donor-specific antibodies not assigned as UAGs.
将检测到有抗体的人类白细胞抗原（HLA）指定为不可接受抗原（UAG）可避免分配HLA不相容的同种异体移植物。但UAG在多大程度上降低获得肾脏供体的概率尚不确定。
对德国六个移植中心等待名单上的3264例患者进行了至少2年的肾脏移植评估。将因UAG导致的排除供体比例计算为虚拟群体反应性抗体（vPRA）。
在常见的欧洲移植肾脏分配方案中，探索性单变量分析显示移植概率不受vPRA影响。在多变量模型中，vPRA值每增加1%，额外等待时间需增加2.5周才能抵消其影响。该模型在来自七个中心的1521例患者的外部验证队列中得到证实。如果仅考虑标准风险患者（例如不同时移植其他器官），则仅需额外等待1.3周。在欧洲移植高级计划中，未经调整的分析显示vPRA值>50%的患者移植概率大幅降低。在多变量模型中，vPRA值每增加1%，额外等待时间需增加5周才能抵消其影响。
本研究表明，由于补偿机制不足，UAG的指定降低了欧洲移植两个主要分配方案中的移植概率。目前，对于免疫患者，必须权衡延长的等待时间与未被指定为UAG的供体特异性抗体增加的免疫风险。
