Hypoxia inducible factor-1α accumulation in steatotic liver preservation: role of nitric oxide

AIM: To examine the relevance of hypoxia inducible factor (HIF-1) and nitric oxide (NO) on the preservation of fatty liver against cold ischemia-reperfusion injury (IRI). METHODS: We used an isolated perfused rat liver model and we evaluated HIF-1α in steatotic and non-steatotic livers preserved for 24 h at 4°C in University of Wisconsin and IGL-1 solutions, and then subjected to 2 h of normothermic reperfusion. After normoxic reperfusion, liver enzymes, bile production, bromosulfophthalein clearance, as well as HIF-1α and NO [endothelial NO synthase (eNOS) activity and nitrites/nitrates] were also measured. Other factors associated with the higher susceptibility of steatotic livers to IRI, such as mitochondrial damage and vascular resistance were evaluated. RESULTS: A significant increase in HIF-1α was found in steatotic and non-steatotic livers preserved in IGL-1 after cold storage. Livers preserved in IGL-1 showed a significant attenuation of liver injury and improvement in liver function parameters. These benefits were enhanced by the addition of trimetazidine (an anti-ischemic drug), which induces NO and eNOS activation, to IGL-1 solution. In normoxic reperfusion, the presence of NO favors HIF-1α accumulation, promoting also the activation of other cytoprotective genes, such as heme-oxygenase-1. CONCLUSION: We found evidence for the role of the HIF-1α/NO system in fatty liver preservation, especially when IGL-1 solution is used

MELD score and serum sodium in the prediction of survival of patients with cirrhosis awaiting liver transplantation

Background/Aims: Serum sodium predicts prognosis in cirrhosis and may improve the prognostic accuracy of the model for end-stage liver disease (MELD) score, but the available information is limited. The aim of the present study was to assess the prognostic value of serum sodium in the prediction of survival at 3 and 12 months after listing in patients with cirrhosis awaiting liver transplantation, and to compare its predictive value with that of the MELD score. Patients and methods: 308 consecutive patients with cirrhosis listed for transplantation during a 5-year period were included in the study. The end-point was survival at 3 and 12 months before transplantation. Variables obtained at the time of listing were analysed for prognostic value using multivariable analysis. Accuracy of prognostic variables was analysed by receiver operating characteristic (ROC) curves. Results: The MELD score and serum sodium concentration were the only independent predictors of survival at 3 and 12 months after listing. Low serum sodium was associated with an increased risk of death in all subpopulations of patients with cirrhosis categorised according to the major complication developed before listing. The area under the ROC curves for serum sodium and MELD score was not significantly different both at 3 months (0.83 vs 0.79, respectively) and at 12 months (0.70 vs 0.77, respectively). The addition of serum sodium did not significantly improve the accuracy of the MELD score in the prediction of survival at 3 and 12 months. Conclusion: In patients with cirrhosis awaiting liver transplantation, serum sodium and MELD were found to be independent predictors of survival. Larger studies are needed to determine whether the addition of serum sodium to MELD can improve its prognostic accuracy