Normothermic Machine Perfusion Combined With Modified Small Interfering RNA Targeting Beta-2-microglobulin and Class II Major Histocompatibility Complex Transactivator Mitigates Acute Rejection of Renal Allograft.

Mesenchymal stromal cell treatment of donor kidneys during ex vivo normothermic machine perfusion: A porcine renal autotransplantation study.

Transplant: immunology and treatment of rejection

Association between IL-6 –174G/C polymorphism and acute rejection of renal allograft: Evidence from a meta-analysis

Previously, it has been demonstrated that heparin inhibits major histocompatibility complex (MHC) class II and intercellular adhesion molecule-1 (ICAM-1) expression on interferon-gamma (IFN-gamma)-stimulated human umbilical vein endothelial cells (HUVECs). Inasmuch as proximal tubular epithelial cells (PTECs) are prime targets in acute renal allograft rejection, we investigated whether there is a difference in the ability of heparin to influence MHC and ICAM-1 expression on PTECs as compared to HUVECs. We also studied whether the degree of sulfation of heparin is of relevance for the binding to IFN-gamma and inhibition of MHC and ICAM-1 expression after IFN-gamma stimulation. Cultured HUVECs and PTECs were stimulated with IFN-gamma for 72 hr in the presence or absence of various heparinoids. MHC and ICAM-1 expression were thereafter determined by fluorescence-activated cell sorting. Heparin was able to inhibit the up-regulation of MHC and ICAM-1 in a dose-dependent fashion on both IFN-gamma-stimulated HUVECs and PTECs. In PTEC cultures, higher concentrations of heparin were required for the inhibition of MHC class I. Heparin and supersulfated glycosaminoglycans (GAGs) were able to bind to IFN-gamma, whereas N-desulfated N-acetylated GAGs with a low amount of sulfate were not. Inhibition of cell-bound heparan sulfate proteoglycan sulfation with NaClO3 resulted in an impaired MHC and ICAM-1 expression after IFN-gamma stimulation. We postulate that IFN-gamma binds to cell-bound heparan sulfate proteoglycan in a sulfation-dependent fashion. This binding may facilitate the interaction of IFN-gamma with its receptor. Supersulfated GAGs with low anti-coagulant activity could be used therapeutically to decrease MHC and ICAM-1 expression on organ grafts.

Neutrophils Mediate Parenchymal Tissue Necrosis and Accelerate the Rejection of Complete Major Histocompatibility Complex-Disparate Cardiac Allografts in the Absence of Interferon-γ

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.

Subsequently,spontaneousliverallograftacceptancewasalsoobservedintransplants done in several allogeneic rat strain combina-tions and most allogeneic mouse strain combinations.Moreover, other experimental studies in rodents demon-strated that allogeneic liver transplantation providesimmune“protection”againstsubsequentcardiac,kidney,pancreas, islet, and skin grafts from the same donor.

Donor or recipient TNF-A −308G/A polymorphism and acute rejection of renal allograft: A meta-analysis

Chapter 25 Class I and II MHC expression and its implications for regeneration in the nervous system

Eosinophils in acute renal allograft rejection

The chemokine receptor CXCR7 is expressed on lymphatic endothelial cells during renal allograft rejection

Introduction:Ageing of the general population has led to an increase in the use of suboptimal kidneys from expanded criteria donation after brain death (ECD-DBD) and donation after circulatory death (DCD) donors. However, these kidneys have inferior graft outcomes and lower rates of immediate function. Normothermic machine perfusion (NMP) may improve outcomes of these suboptimal donor kidneys. Previous non-randomized studies have shown the safety of this technique and suggested its efficacy in improving the proportion of immediate functioning kidneys compared to static cold storage (SCS). However, its additional value to hypothermic machine perfusion (HMP), which has already been proved superior to SCS, has not yet been established.Methods and analysis:This single-center, open-label, randomized controlled trial aims to assess immediate kidney function after 120 minutes additional, end-ischemic NMP compared to HMP alone. Immediate kidney function is defined as no dialysis treatment in the first week after transplant. Eighty recipients on dialysis at the time of transplant who receive an ECD-DBD or DCD kidney graft are eligible for inclusion. In the NMP group, the donor kidney is taken of HMP upon arrival in the recipient hospital and thereafter put on NMP for 120 minutes at 37 degrees Celsius followed by transplantation. In the control group, donor kidneys stay on HMP until transplantation. The primary outcome is immediate kidney function.Ethics and dissemination:The protocol has been approved by the Medical Ethical Committee of Erasmus Medical Center (2020-0366). Results of this study will be submitted to peer-reviewed journals.Registration:registered in clinicaltrials.gov (NCT04882254).Highlights:This is the first RCT to compare additional NMP to HMP alone.Extensive sampling will offer in-depth analysis of kidney physiology during NMP.This RCT may help identify biomarkers to predict clinical outcomes during NMP.Biomarkers can help develop NMP as assessment tool for declined kidneys.

Immunosuppressive medications for renal transplantation: A multiple choice question

The shortage of donor kidneys is a worldwide problem. One possibility to increase the donor organ pool is to improve the quality of suboptimal donor kidneys. For this reason, an increasing amount of research is being performed on the subject of machine perfusion, a technique during which an organ is connected to a perfusion circuit. Apart from the fact that this technique can be used to bridge the period between donation and actual transplantation, it also provides the opportunity for active interventions to an isolated organ. The first part of my thesis focuses on a cellular intervention during normothermic (37 degrees) machine perfusion with mesenchymal stromal cells. The aim was to determine if it was technically feasible to administer mesenchymal stromal cells, cells with regenerative capacities, during normothermic machine perfusion and what effect these cells had on the donor kidney. It proved to be feasible to administer these cells in such way that a proportion remained detectable after machine perfusion. In a porcine autotransplantation model, mesenchymal stromal cells did not affect early graft function, but further research is necessary to determine if these cells could have a beneficial effect on longer term graft function of the donor kidney. The second part of my thesis focuses on the use of different perfusion solutions and oxygen carriers during normothermic machine perfusion. From these experiments it can be concluded that the composition of the perfusion solution, as well as the choice for a specific oxygen carrier, has a significant impact on kidney function and injury markers during normothermic machine perfusion.

Lohmann 1/M. Pool 2, K. Rozenberg 3, M. Eijken 4, U. Møldrup 5, B.K. Møller 6, J.M. Sierra Parraga 7, M. Hoogduijn 7, L. Lo Faro 3, C. Moers 2, J. Hunter 3, A.K. Keller 1, H. Leuvenink 2, C.C. Baan 7, R.J. Ploeg 3, B. Jespersen 1 Department of Clinical Medicine, Aarhus University, Aarhus, Denmark Department of Surgery, University Medical Center Groningen, Groningen, The Netherlands Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark Department of Urology, Aarhus University Hospital, Aarhus, Denmark Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark Department of Internal Medicine, Nephrology and Transplantation, Erasmus MC, University Medical Center, Rotterdam, the Netherlands Introduction Marginal kidneys are increasingly being accepted to decrease waiting time for a transplant. Normothermic machine perfusion (NMP) is a technique that allows delivery of therapies that may help condition or repair the organ prior to transplantation. Mesenchymal stromal cells (MSC) may be able to ameliorate ischaemia reperfusion injury as they possess potent anti-inflammatory and regenerative properties. We investigated the safety and effect of MSCs administered during ex vivo NMP prior to transplantation in a pig auto-transplant model of donation after circulatory death. Methods Porcine kidneys subjected to 75 min warm ischaemia were retrieved and preserved for 14h by oxygenated HMP (oxHMP) and 4h NMP and then auto-transplantation. Kidneys were randomised to three different intervention strategies (n=7 per group): following 1h NMP, either a vehicle (NMP), 10 million pig MSC (NMP+pMSC) or 10 million human MSC (NMP+hMSC) were intra-arterially infused. The NMP groups were all compared to a control group, where kidneys were only preserved with oxHMP. The pig was re-anaesthetised, the contralateral kidney was removed and the treated kidney was auto-transplanted and the animals were recovered for 14 days. Results Renal blood flow during NMP was no different between the groups (p=0.0685). Post-transplant plasma creatinine increased in all groups but there were no significant differences between the groups (p=0.517). Plasma kidney injury biomarker NGAL was significantly higher in the NMP+pMSC group compared to the NMP (p=0.003) and NMP+hMSC (p=0.017) groups at day 14. On day 14, mGFR significantly improved in the NMP group compared to the control (55 ± 3 vs 42 ± 12 ml/min, p=0.025). No differences in GFR were observed on day 14 in the other groups (NMP+pMSC, p=0.090 and NMP+hMSC, p=0.387). MSC were detectable in biopsies of MSC treated kidney after NMP and post-transplantation. Conclusion NMP alone improved renal graft function compared to oxHMP of DCD kidneys post-transplant. The method of MSC administration during NMP proved to be safe, however in this model MSC treatment did not improve renal function. Nevertheless viable MSC remained detectable in the transplanted kidney at postoperative day 14 which may have an effect on longer term outcomes.