H Gibelin

Protection of autotransplanted pig kidneys from ischemia-reperfusion injury by polyethylene glycol

Background. Ischemia-reperfusion injury (IRI) is often responsible for graft rejection and leads to delayed graft function of cadaveric kidneys. We have shown that adding polyethylene glycol (PEG 20M) to the preservation solutions helps protect isolated perfused pig kidneys against cold ischemia and reperfusion injury. Methods. We compared the effects of adding PEG to a simplified high-K+ perfusion solution of cold-stored kidneys to Euro-Collins or University of Wisconsin solutions on the function of reperfused autotransplanted pig kidneys. The left kidney was cold-flushed with the preservation solutions and stored for 48 hr at 4°C before reimplantation. Creatinine clearance and fractional excretion of sodium were analyzed 2 days before surgery and over 7 days after transplantation. Histological sections were obtained 40 min after reperfusion and on day 7 after surgery. Results. Adding PEG to the perfusate significantly reduced IRI from autotransplanted pig kidneys. Creatinine clearance was significantly higher and fractional excretion of sodium was significantly lower in pigs transplanted with kidneys cold-flushed with PEG-supplemented perfusate than in those flushed with Euro-Collins or University of Wisconsin solutions. PEG supplementation also better preserved the integrity of kidney cells and markedly reduced interstitial cell infiltrates. Conclusion. PEG protects against IRI and reduces early cellular inflammation. PEG may impair the recruitment and migration of leukocytes into retransplanted pig kidneys. Cold preservation of donor organs with PEG-supplemented solutions may therefore help limit IRI in human renal transplantation.

Citrate, acetate and renal medullary osmolyte excretion in urine as predictor of renal changes after cold ischaemia and transplantation.

Abstract In organ transplantation, the determination of reliable parameters to assess ischaemic damage is essential to predict renal injury after preservation. The aim of this study was to assess renal medullary injury by 1H NMR (proton nuclear magnetic resonance) spectroscopy after preservation and reperfusion. Three experimental groups of pigs were examined during a 2-week period: control group (n = 4), Euro-Collins group (EC) (cold flushed and 48 h cold storage of kidney in EC and autotransplantation, n = 7), and University of Wisconsin (UW) group (cold flushed and 48 h cold storage of kidney in UW and autotransplantation, n = 7). Creatinine and urea were improved in the two cold stored groups. The most relevant resonances determined by 1H NMR spectroscopy after transplantation were those arising from citrate and acetate in urine and trimethylamine-N-oxide (TMAO) in urine and plasma. We demonstrate that graft dysfunction is associated with damage to the renal medulla as determined by TMAO release in urine and plasma. Conversely, citrate excretion can discriminate kidneys with favourable outcome. This study outlines the specific and beneficial impact of UW solution on renal preservation and suggests that 1H NMR spectroscopy is efficient both to detect ischaemic damage of preserved kidneys and to discriminate the preservation quality between different preservation solutions.

Kidney retrieval conditions influence damage to renal medulla : Evaluation by proton nuclear magnetic resonance (NMR) spectroscopy

Abstract In the present investigation, the influence of retrieval condition on medullary damage in kidneys was assessed. The isolated perfused pig kidney was used to assess initial renal function from multiorgan donors or single organ donors after cold flush and 24 h cold storage preservation with two preservation solutions: Euro-Collins and University of Wisconsin solutions. Kidneys flushed with cold heparinized saline and immediately perfused were used as a control group. Kidneys were perfused for 90 min at 37.5°C and renal perfusion flow rate, glomerular filtration rate, tubular reabsorption of Na+ and lactate dehydrogenase and N-acetyl-β-D-glucosaminidase excretion were determined. Ischaemia reperfusion impairment was also determined by 1H NMR (proton nuclear magnetic resonance) spectroscopy. Renal function was significantly decreased in experimental groups when compared to the control group, but there was no significant difference between experimental groups after 24 h cold storage. The release of lactate dehydrogenase in the effluent and the urinary excretion of N-acetyl-β-D-glucosaminidase were not significantly different after 24 h cold storage. The most relevant resonances determined by 1H NMR spectroscopy were citrate, trimethylamine-N-oxide, lactate, acetate and amino acids. Excretion of these markers was significantly different when compared to biochemical markers. A resonance P (Peak) detected particularly in Euro-Collins solution multiorgan donors after 24 h cold storage was identified and well correlated to renal dysfunction. N-acetyl-β-D-glucosaminidase spectroscopy, which is a non-invasive and non-destructive technique, is more efficient to assess renal damage than conventional histology and biochemical analysis.

A new approach to the evaluation of liver graft function by nuclear magnetic resonance spectroscopy. A comparative study between Euro-Collins and University of Wisconsin solutions

Abstract The incidence of primary dysfunction or non-function of liver grafts still occurs at an unacceptable rate and the identification of new markers of graft viability and metabolic capacity is essential. Proton nuclear magnetic resonance (H NMR) spectroscopy has previously shown potential in the evaluation of renal allograft dysfunction after ischaemia reperfusion. The aim of this study was to compare liver graft function in a rat isolated perfused liver model after 24 hours of preservation in either Euro-Collins (EC) or University of Wisconsin (UW) solutions. Livers were reperfused for 90 min with a modified Krebs-Henseleit medium. Functional parameters measured were: pressure and resistances, bile and transaminase production. The production of lactate, pyruvate, citrate and succinate, β-hydroxybutyrate and aceto-acetate was measured by H NMR. There was a significant difference in both haemodynamics and bile production in favour of the UW group. The transaminases were similar in the two groups. Measurements of citrate, succinate and ketone bodies by H NMR were all higher in the UW group. These markers indicate better metabolic function of these grafts during reperfusion. In conclusion, discriminating different hepatic metabolic pathways is possible and easy by H NMR and can be used to assess both the preservation quality of liver grafts and their functional recovery.

Ischemia-reperfusion injury is associated with inflammatory cell infiltration: evaluation in a pig kidney autotransplant model.

DAMAGE sustained by the allograft during the process of transplantation has been shown to be influenced by cold ischemia-reperfusion injury, which is one of the principal “antigen-independent” factors. A previous study demonstrated that tissue injury occurs within isografts as compared to allografts, in the absence of alloantigen stimulation. In a rat model, a recent report suggests that molecules involved in T-cell costimulation may play a key role in ischemia-reperfusion in the kidney, independent of any alloimmune stimuli. The aim of this study was to assess the effect of the length of cold ischemic time in an autotransplant pig kidney model on delayed graft function and inflammatory cell infiltration.

Evaluation of renal medulla injury after cold preservation and transplantation: noninvasive determination of medullar damage by proton nuclear magnetic resonance spectroscopy of urine and plasma ☆

PRIMARY and early allograft dysfunction remains a challenge for the nephrologist. Usually, the assessment of renal graft dysfunction following transplantation is based on nonspecific measurement of renal function or an invasive method such as transplant biopsy. A rapid diagnosis is necessary because a delay in treating early rejection deteriorates the prognosis of the allograft function. In addition, the antirejection treatment based on a mere clinical diagnosis of rejection could improve delayed graft function caused by acute tubular necrosis or cyclosporine damage through possible side effects of antirejection treatment. In the present study, we wanted to assess whether proton nuclear magnetic resonance (HNMR) spectroscopy can detect ischemic damage and predict acute tubular necrosis after pig kidney preservation in two preservation solutions (Euro-Collins: EC and University of Wisconsin: UW).

Comparison of Euro-Collins and university of wisconsin solutions in the isolated perfused rat liver model: evaluation by proton nuclear magnetic resonance spectroscopy.

PRIMARY dysfunction or nonfunction of liver graft is still an important problem in liver transplantation despite surgical progress. The determination of new markers of graft viability and metabolic activities seems to be an important challenge to assess the early graft function. Proton nuclear magnetic resonance spectroscopy (NMRp) has previously demonstrated its interest in the evaluation of renal allograft dysfunction after ischemia reperfusion in isolated perfused pig kidney. For the kidney, NMRp study determines specific markers of function like TMAO and citrate. The aim of this study was to assess liver graft function in an isolated perfused rat liver model after 24 hours of preservation in Euro-Collins (EC) or University of Wisconsin (UW) solution.

Limitation of lipid peroxidation and renal medullary cell injury of the kidney after 48- and 72-hour cold storage in university of wisconsin solution: effect of trimetazidine ☆

ISCHEMIA-reperfusion injury after organ transplantation is a major cause of delayed graft function. The pathogenesis of ischemia-reperfusion injury are well correlated with alterations in mitochondrial function, namely, decrease in ATP synthesis, NAD(P)H level, and mitochondrial membrane potential and generation of mitochondrial permeability transition. A previous study has demonstrated that the pretreatment with trimetazidine (TMZ) prevented these ischemia-reperfusion deleterious effects at both the cellular and mitochondrial level. The aim of this study was to assess the effect of TMZ added to University of Wisconsin Solution (UW) during cold preservation in an isolated perfused pig kidney model against lipid peroxidation and renal medulla damage. After cold preservation (CP), kidneys were perfused as previously described.