The hypotaurine-taurine pathway as an antioxidative mechanism in patients with acute liver failure.

The liver has been thought to protect against oxidative stress through mechanisms involving reduced glutathione (GSH) that consumes high-energy phosphor-nucleotides on its synthesis. However, hepatoprotective mechanisms in acute liver failure (ALF) where the phosphor-nucleotides are decreased in remain to be solved. Liver tissues were collected from patients with ALF and liver cirrhosis (LC) and living donors (HD) who had undergone liver transplantation. Tissues were used for metabolomic analyses to determine metabolites belonging to the central carbon metabolism, and to determine sulfur-containing metabolites. ALF and LC exhibited a significant decline in metabolites of glycolysis and pentose phosphate pathways and high-energy phosphor-nucleotides such as adenosine triphosphate as compared with HD. Conversely, methionine, S-adenosyl-l-methionine, and the ratio of serine to 3-phosphoglycerate were elevated significantly in ALF as compared with LC and HD, suggesting a metabolic boost from glycolysis towards trans-sulfuration. Notably in ALF, the increases in hypotaurine (HTU) + taurine (TU) coincided with decreases in the total amounts of reduced and oxidized glutathione (GSH + 2GSSG). Plasma NH3 levels correlated with the ratio of HTU + TU to GSH + 2GSSG. Increased tissue levels of HTU + TU vs total glutathione appear to serve as a biomarker correlating with hyperammonemia, suggesting putative roles of the HTU-TU pathway in anti-oxidative protective mechanisms.

Simeprevir/pegylated interferon/ribavirin triple therapy for recurrent hepatitis C after living donor liver transplantation.

AIM: Simeprevir (SMV) is a protease inhibitor which demonstrates good tolerability and high antiviral response in patients with hepatitis C. The clinical outcomes of triple therapy using simeprevir, pegylated interferon and ribavirin (SMV/PEG IFN/RBV) for recurrent hepatitis C after living donor liver transplantation (LDLT) have not been well reported. In this study, we assessed the outcomes of patients with recurrent hepatitis C (genotype 1) after LDLT who received triple therapy at our hospital. METHODS: SMV/PEG IFN/RBV was administrated for 12 weeks (triple therapy), followed by another 12 weeks or extended period of PEG IFN/RBV (dual therapy). Virological response, interaction with calcineurin inhibitors and adverse events were retrospectively analyzed. RESULTS: Ten patients with recurrent hepatitis C after LDLT completed 12 weeks of triple therapy. Nine patients achieved rapid or early virological response, and one patient was a non-responder. The nine responders received subsequent dual therapy, and the duration of dual therapy was extended (24 to 36 weeks) in five cases. Although one patient was in relapse 8 weeks after completing the standard duration (12 weeks) of dual therapy, eight patients achieved sustained virological response for 12 weeks (SVR12). The SVR12 rate was 80%. Trough levels of calcineurin inhibitor did not show marked changes after introduction of SMV in all cases. There were no major adverse events associated with SMV. CONCLUSION: SMV treatment may be a safe and effective option for recurrent hepatitis C after LDLT.

Hemoadsorption of high-mobility-group box 1 using a porous polymethylmethacrylate fiber in a swine acute liver failure model.

BACKGROUND: High-mobility-group box chromosomal protein 1 has been identified as an important mediator of various kinds of acute and chronic inflammation. In this study, we aimed to develop a column that effectively adsorbs high-mobility-group box chromosomal protein 1 by altering the pore size of the fiber. MATERIALS AND METHODS: First, we produced three types of porous polymethylmethacrylate fiber by altering the concentration of polymethylmethacrylate dissolved in dimethylsulfoxide. We then selected a fiber based on the results of an in vitro incubation test of high-mobility-group box chromosomal protein 1 adsorption. Using the selected fiber, we constructed a new column and tested its high-mobility-group box chromosomal protein 1 adsorption capacity during 4-h extracorporeal hemoperfusion in a swine acute liver failure model. RESULTS: Electron microscope observation showed that the three types of fibers had different pore sizes on the surface and in cross section, which were dependent on the concentration of polymethylmethacrylate. In the in vitro incubation test, fiber with moderate-sized pores demonstrated the highest adsorption capacity. In the in vivo hemoperfusion study, the ratio of the high-mobility-group box chromosomal protein 1 concentration at the outlet versus the inlet of the column was significantly lower with the new column than with the control column during 4-h extracorporeal hemoperfusion. The normalized plasma level of high-mobility-group box chromosomal protein 1 at 12 h after the completion of hemoperfusion was significantly lower with the new column than with the control column. CONCLUSION: The newly developed polymethylmethacrylate column adsorbs high-mobility-group box chromosomal protein 1 during hemoperfusion in swine ALF model.