Protective roles of polyethylene glycol and trimetazidine against cold ischemia and reperfusion injuries of pig kidney graft

Ischemia-reperfusion injury (IRI) represents an allo-independent risk factor which favors chronic allograft nephropathy (CAN). Here we analyzed the influence of preservation solutions on the function of autotransplanted pig kidneys over 1-16 weeks after surgery. Kidneys were cold-flushed and cold-stored for 24 or 48 h either in University of Wisconsin (UW), modified-UW Hospital Edouard Herriot, polyethylene glycol 20 kDa (PEG)-supplemented preservation solutions with low K+ (ECPEG) or high K+ (ICPEG) content. Animals autotransplanted with kidneys cold-stored for 24 h in ECPEG exhibited the greatest levels of creatinine clearance (C-cr: 161+/-12 mL/min, n=10) and the lowest levels of proteinuria (0.5+/-0.03 mg/mL) 16 weeks after surgery as compared with pigs autotransplanted with kidneys cold-stored in the other solutions tested (C-cr ranging from 80 and 140 mL/min). Similar differences, but with lower C-cr levels, were achieved after a prolonged period of cold-storage(48 h). ECPEG better preserved the kidneys from monocytes/macrophages and CD4(+) T cells infiltrations, VCAM-1 and MHC class II overexpressions and occurrence of renal interstitial fibrosis (2%) as compared with the other preservation solutions (5%-20%). Adding the anti-ischemic drug trimetazidine (TMZ) to the preservation solutions, particularly ECPEG, further improved the quality of the week-16 post-transplanted kidneys (C-cr: 182+/-12 mL/min, n=10). These findings demonstrated that adding PEG to extracellular-like (with low K+ content) preservation solutions in combination with TMZ significantly improved the long-term outcome of kidney grafts in this model of autotransplanted pig kidney.