Machine perfusion preservation versus static cold storage for deceased donor kidney transplantation.

Ex vivo normothermic machine perfusion (NMP) of donor kidneys prior to transplantation provides a platform for direct delivery of cellular therapeutics to optimize organ quality prior to transplantation. Multipotent Adult Progenitor Cells (MAPC®) possess potent immunomodulatory properties that could minimize ischemia reperfusion injury. We investigated the potential capability of MAPC cells in kidney NMP. Pairs (5) of human kidneys, from the same donor, were simultaneously perfused for 7 hours. Kidneys were randomly allocated to receive MAPC treatment or control. Serial samples of perfusate, urine, and tissue biopsies were taken for comparison. MAPC‐treated kidneys demonstrated improved urine output (P = .009), decreased expression of injury biomarker NGAL (P = .012), improved microvascular perfusion on contrast‐enhanced ultrasound (cortex P = .019, medulla P = .001), downregulation of interleukin (IL)‐1β (P = .050), and upregulation of IL‐10 (P < .047) and Indolamine‐2, 3‐dioxygenase (P = .050). A chemotaxis model demonstrated decreased neutrophil recruitment when stimulated with perfusate from MAPC‐treated kidneys (P < .001). Immunofluorescence revealed prelabeled MAPC cells in the perivascular space of kidneys during NMP. We report the first successful delivery of cellular therapy to a human kidney during NMP. Kidneys treated with MAPC cells demonstrate improvement in clinically relevant parameters and injury biomarkers. This novel method of cell therapy delivery provides an exciting opportunity to recondition organs prior to transplantation.

Combining NAR and Ca19-9 into a prognostic score allows stratification of unresectable PDAC patients into groups with significantly different overall survival.

Normothermic machine perfusion (NMP) is a novel clinical approach to overcome the limitations of traditional hypothermic organ preservation. NMP can be used to assess and recondition organs prior to transplant and is the subject of clinical trials in solid organ transplantation. In addition, NMP provides an opportunity to deliver therapeutic agents directly to the organ, thus avoiding many limitations associated with systemic treatment of the recipient. We report the delivery of oligonucleotide‐based therapy to human kidneys during NMP, in this case to target microRNA function (antagomir). An antagomir targeting mir‐24‐3p localized to the endothelium and proximal tubular epithelium. Endosomal uptake during NMP conditions facilitated antagomir co‐localization with proteins involved in the RNA‐induced silencing complex (RISC) and demonstrated engagement of the miRNA target. This pattern of uptake was not seen during cold perfusion. Targeting mir‐24‐3p action increased expression of genes controlled by this microRNA, including heme oxygenase‐1 and sphingosine‐1‐phosphate receptor 1. The expression of genes not under the control of mir‐24‐3p was unchanged, indicating specificity of the antagomir effect. In summary, this is the first report of ex vivo gymnotic delivery of oligonucleotide to the human kidney and demonstrates that NMP provides the platform to bind and block detrimental microRNAs in donor kidneys prior to transplantation.

Background There remains a lack of consensus on the optimal storage method for deceased donor kidneys. This meta‐analysis compares storage with hypothermic machine perfusion (HMP) vs traditional static cold storage (SCS). Methods The Cochrane Kidney and Transplant Specialised Register was searched to identify (quasi‐) randomized controlled trials (RCTs) to include in our meta‐analysis. PRISMA guidelines were used to perform and write this review. Results There is high‐certainty evidence that HMP reduces the risk of delayed graft function (DGF) when compared to SCS (2138 participants from 14 studies, RR = 0.77; 0.67‐0.90, P = .0006). This benefit is significant in both donation following circulatory death (DCD; 772 patients from seven studies, RR = 0.75; 0.64‐0.87, P = .0002) and donation following brainstem death (DBD) grafts (971 patients from four studies, RR = 0.78; 0.65‐0.93, P = .006). The number of perfusions required to prevent one episode of DGF was 7.26 and 13.60 in DCD and DBD grafts, respectively. There is strong evidence that HMP also improves graft survival in both DBD and DCD grafts, at both 1 and 3 years. Economic analyses suggest HMP is cost‐saving at 1 year compared with SCS. Conclusion Hypothermic machine perfusion is superior to SCS in deceased donor renal transplantation. Direct comparisons with normothermic machine perfusion in RCTs are essential to identify optimal preservation methods in kidney transplantation.