Ex Vivo Administration of Mesenchymal Stromal Cells in Kidney Grafts Against Ischemia-reperfusion Injury—Effective Delivery Without Kidney Function Improvement Posttransplant

Abstract

Background: Mesenchymal stromal cell (MSC) therapy may improve renal function after ischemiareperfusion injury in transplantation. Ex-vivo renal intra-arterial administration is a targeted delivery method, avoiding the lung vasculature, a known barrier for cellular therapies. In a randomized and blinded study, we tested the feasibility and effectiveness of MSC therapy in a donation after circulatory death autotransplantation model to improve posttransplant kidney function, using an ex-vivo MSC delivery method similar to the clinical standard procedure of pretransplant cold graft flush.Methods: Kidneys exposed to 75 min of warm ischemia and sixteen hrs of static cold storage were intraarterially infused ex-vivo with ten million male porcine MSCs (Tx-MSC, n=8) or vehicle (Tx-control, n=8).Afterwards, the kidneys were autotransplanted after contralateral nephrectomy. Biopsies an hour after reperfusion confirmed the presence of MSCs in the renal cortex. Animals were observed for fourteen days.Results: Postoperatively, peak p-creatinine was 1230 and 1274 µmol/L (Tx-controls vs Tx-MSC, p=0.69).During follow up, no significant differences over time were detected between groups regarding p-creatinine, p-NGAL, or u-NGAL/creatinine ratio. At day fourteen measured glomerular filtration rates were 40 and 44 mL/min, p=0.66. Renal collagen content and fibrosis related mRNA expression were increased in both groups but without significant differences between the groups.In conclusion, we demonstrated intra-arterial MSC infusion to transplant kidneys as a safe and effective method to deliver MSCs to the graft. However, we could not detect any positive effects of this cell treatment within fourteen days of observation.

Assessment of Mitochondrial Function and Oxygen Consumption Measured During Ex Vivo Normothermic Machine Perfusion of Injured Pig Kidneys Helps to Monitor Organ Viability

“…The original study design included paired kidneys to compare a “gold standard” healthy control with kidney injury that was at the extent of what would be considered viable. 60 min warm ischaemia with 24 h cold ischaemia was selected, as the combination of WI and CI was clinically relevant, and the durations were based on previous work that showed 75 min WI plus 16 h CI followed by auto-transplant led to significant but recoverable acute kidney injury [ 11 ]. During the project it became clear that in some of the kidneys the injury sustained was unrecoverable, as they were significantly deteriorating and appeared to be non-viable during NMP.…”

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

“…All personnel involved had Federation of European Laboratory Animal Science Associations licenses. Our animal experiment refinements have been reported 26,27 …”

“…Two‐micrometer thick sections of FFPE‐harvested tissue were stained with hematoxylin and eosin, Masson's trichrome as well as periodic acid–Schiff, and slides were analyzed by an experienced renal pathologist, blinded to the intervention and cases. Samples were compared to healthy kidney tissue 27 to assess evidence of inflammation, tubular atrophy, fibrosis, tubular and glomerular damage. Each parameter was scored semi‐quantitatively on a 0–4 scale based on the degree of injury: 0 if <2% was affected, 1 if 2%–5% was affected, 2 if 6%–25% was affected, 3 if 25%–50% was affected, and 4 if 51%–100% was affected.…”

Mesenchymal Stem Cell Protects Injured Renal Tubular Epithelial Cells by Regulating mTOR-Mediated Th17/Treg Axis

“…Currently, MSC has been extensively reported as a promising therapy for renal injury due to its renoprotection for injured RTEC (91)(92)(93). However, the therapeutic effect of MSC was greatly weakened in the light of the fact that a majority of MSC were stuck in the lungs after adoptive transfer, with a small part reaching to the spleen, liver, renal, and other organs (1,94).…”