Biomarkers of oxidative damage to predict ischaemia-reperfusion injury in an isolated organ perfusion model of the transplanted kidney.

Ischaemia-reperfusion (IR) injury is known to be a risk factor influencing both short and long-term graft function following transplantation. The pathophysiology of IR injury is suggested to involve elevated reactive oxygen species production resulting in oxidative damaged cellular macromolecules. The objective of this study was to evaluate oxidative damage following IR using an isolated organ perfusion model of the transplanted kidney, in order to determine a simple, preferably non-invasive biomarker for IR injury. Porcine kidneys were retrieved with 10 or 40 min warm ischaemic (WI) time and haemoperfused for 6 h on an isolated organ perfusion machine. ELISA was used to detect carbonyls, 8-isporostane and 8-hydroxy-2'-deoxyguanosine, representing protein, lipid and DNA damage respectively in pre and post reperfusion samples of plasma, urine and biopsy material. Plasma carbonyl and 8-isporostane and were significantly increased in the 40 min group compared to pre-perfusion (0.96 +/- 0.10 vs. 0.62 +/- 0.06, P < 0.001 and 1.57(1.28-4.9) vs. 0.36(0.09-0.59), P < 0.05). The levels also correlated with creatinine clearance used to determine renal function (r = - 0.6150, P < 0.01 and r = - 0.7727, P < 0.01). The results of this study suggest both plasma carbonyl and 8-isporostane to be reliable biomarkers to predict the level IR injury.