Bahadori Kasra, Lee Colin Y C, Ferdinand John R, Cabantous Mia, Butler Andrew J, Rouhani Foad J, Watson Christopher J E, Clatworthy Menna R
Molecular Immunity Unit, Department of Medicine, Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom.
National Institute of Health Research Blood and Transplant Research Unit in Organ Donation and Transplantation, Cambridge, United Kingdom.
Transplantation. 2025 Feb 1;109(2):332-345. doi: 10.1097/TP.0000000000005214. Epub 2025 Jan 20.
Ex situ normothermic perfusion (ESNP) is a method to evaluate and potentially recondition organs before transplantation. However, increased expression of inflammatory molecules, including by tissue-resident immune cells, may occur during the perfusion process, potentially negating the beneficial effects of perfusion.
We used RNA sequencing to assess gene expression in 31 livers undergoing ESNP, including 23 donated after circulatory death (DCD) and 8 donated after brain death. In 7 DCD livers, a leucocyte filter was added to the circuit during perfusion. Biopsies were available for transcriptomic assessment in all cases at the start of perfusion and at varying time points postperfusion.
During ESNP in DCD livers, we observed an increase in proinflammatory, profibrinolytic, and prorepair pathway genes. SERPINE1 , encoding plasminogen activator inhibitor-1, was among the genes most significantly upregulated during perfusion in DCD livers, potentially promoting fibrin clot persistence in vasculature. We also found increased expression of monocyte and neutrophil recruiting chemokine and proinflammatory cytokine transcripts during ESNP, but several prorepair molecules, including thymic stromal lymphopoietin, were also upregulated. In both DCD and donation after brain death livers, interferon-gamma response genes were enriched, whereas oxidative phosphorylation genes decreased in organs with high perfusate alanine transaminase, a biomarker associated with adverse clinical outcomes. The inclusion of a leukocyte filter in the perfusion circuit mitigated the induction of inflammation/immune pathway genes during perfusion and was associated with enrichment in oxidative phosphorylation genes.
Leukocyte removal during ESNP abrogates transcriptional changes that are associated with unfavorable clinical outcomes, potentially benefiting human livers undergoing ESNP.
体外常温灌注（ESNP）是一种在移植前评估并可能对器官进行预处理的方法。然而，在灌注过程中可能会出现炎症分子表达增加，包括组织驻留免疫细胞产生的炎症分子，这可能会抵消灌注的有益效果。
我们使用RNA测序来评估31个接受ESNP的肝脏中的基因表达，其中包括23个循环死亡后捐赠（DCD）的肝脏和8个脑死亡后捐赠的肝脏。在7个DCD肝脏中，灌注过程中在回路中添加了白细胞过滤器。在灌注开始时以及灌注后的不同时间点，所有病例均有活检样本可用于转录组评估。
在DCD肝脏的ESNP过程中，我们观察到促炎、纤溶和修复途径基因增加。编码纤溶酶原激活物抑制剂-1的SERPINE1是DCD肝脏灌注过程中上调最显著的基因之一，可能会促进血管系统中纤维蛋白凝块的持续存在。我们还发现在ESNP过程中单核细胞和中性粒细胞募集趋化因子以及促炎细胞因子转录本的表达增加，但包括胸腺基质淋巴细胞生成素在内的几种修复分子也上调。在DCD和脑死亡后捐赠的肝脏中，干扰素γ反应基因均富集，而在灌注液丙氨酸转氨酶水平较高的器官中氧化磷酸化基因减少（灌注液丙氨酸转氨酶是与不良临床结果相关的生物标志物）。在灌注回路中加入白细胞过滤器可减轻灌注过程中炎症/免疫途径基因的诱导，并与氧化磷酸化基因的富集相关。
ESNP过程中去除白细胞可消除与不良临床结果相关的转录变化，这可能对接受ESNP的人类肝脏有益。
