SRS295 - Assessing the effect of oxidative stress on pig kidneys during normothermic machine perfusion

Abstract Introduction Ischaemia reperfusion injury (IRI) is a detrimental part of organ transplantation, damaging previously ischaemic tissue upon reperfusion. Evidence suggests that reactive oxygen species (ROS) generated during ischaemia activate the intracellular kinase, receptor interacting protein kinase 1 (RIPK-1), culminating in a form of programmed cell death called necroptosis. The clinical challenge is to reduce IRI in donor kidneys to minimise graft failure. In a novel experiment, we investigated the effect of a recently developed RIPK-1 inhibitor in reducing oxidative stress in porcine kidneys undergoing normothermic reperfusion (NR) in an ex-vivo setup. Methods Kidneys were divided into control (n = 6) or treatment groups (n = 6) and underwent 12 h hypothermic machine perfusion (HMP) followed by 8 h NR. Perfusion parameters including renal blood flow and intrarenal resistance were monitored. Concentrations of malondialdehyde and 4-hydroxynonenal, determined by enzyme-linked immunosorbent assays (ELISAs), were used as surrogate markers of oxidative stress. Results The RIPK-1 inhibitor had no significant effect on perfusion parameters. The drug significantly reduced 4-HNE concentrations compared to controls but had no significant effect on MDA concentrations. Discussion This study was a novel investigation into the effects of a RIPK-1 inhibitor on porcine kidneys undergoing NR. We conclude that the delivery of the new therapy was safe and feasible, with no negative effects on perfusion parameters. We determine that the effect of the drug on oxidative stress is unclear due to conflicting results from MDA and 4-HNE assays. Future studies should investigate the 4-HNE reduction and evaluate dosage of the drug.