Prospects for the temporary treatment of acute liver failure

Gasdermin E-derived caspase-3 inhibitors effectively protect mice from acute hepatic failure

Programmed cell death (PCD), including apoptosis, apoptotic necrosis, and pyroptosis, is involved in various organ dysfunction syndromes. Recent studies have revealed that a substrate of caspase-3, gasdermin E (GSDME), functions as an effector for pyroptosis; however, few inhibitors have been reported to prevent pyroptosis mediated by GSDME. Here, we developed a class of GSDME-derived inhibitors containing the core structure of DMPD or DMLD. Ac-DMPD-CMK and Ac-DMLD-CMK could directly bind to the catalytic domains of caspase-3 and specifically inhibit caspase-3 activity, exhibiting a lower IC50 than that of Z-DEVD-FMK. Functionally, Ac-DMPD/DMLD-CMK substantially inhibited both GSDME and PARP cleavage by caspase-3, preventing apoptotic and pyroptotic events in hepatocytes and macrophages. Furthermore, in a mouse model of bile duct ligation that mimics intrahepatic cholestasis-related acute hepatic failure, Ac-DMPD/DMLD-CMK significantly alleviated liver injury. Together, this study not only identified two specific inhibitors of caspase-3 for investigating PCD but also, more importantly, shed light on novel lead compounds for treating liver failure and organ dysfunctions caused by PCD.

Hepatocyte nuclear factor 4A improves hepatic differentiation of immortalized adult human hepatocytes and improves liver function and survival

Immortalized human hepatocytes (IHH) could provide an unlimited supply of hepatocytes, but insufficient differentiation and phenotypic instability restrict their clinical application. This study aimed to determine the role of hepatocyte nuclear factor 4A (HNF4A) in hepatic differentiation of IHH, and whether encapsulation of IHH overexpressing HNF4A could improve liver function and survival in rats with acute liver failure (ALF). Primary human hepatocytes were transduced with lentivirus-mediated catalytic subunit of human telomerase reverse transcriptase (hTERT) to establish IHH. Cells were analyzed for telomerase activity, proliferative capacity, hepatocyte markers, and tumorigenicity (c-myc) expression. Hepatocyte markers, hepatocellular functions, and morphology were studied in the HNF4A-overexpressing IHH. Hepatocyte markers and karyotype analysis were completed in the primary hepatocytes using shRNA knockdown of HNF4A. Nuclear translocation of β-catenin was assessed. Rat models of ALF were treated with encapsulated IHH or HNF4A-overexpressing IHH. A HNF4A-positive IHH line was established, which was non-tumorigenic and conserved properties of primary hepatocytes. HNF4A overexpression significantly enhanced mRNA levels of genes related to hepatic differentiation in IHH. Urea levels were increased by the overexpression of HNF4A, as measured 24h after ammonium chloride addition, similar to that of primary hepatocytes. Chromosomal abnormalities were observed in primary hepatocytes transfected with HNF4A shRNA. HNF4α overexpression could significantly promote β-catenin activation. Transplantation of HNF4A overexpressing IHH resulted in better liver function and survival of rats with ALF compared with IHH. HNF4A improved hepatic differentiation of IHH. Transplantation of HNF4A-overexpressing IHH could improve the liver function and survival in a rat model of ALF.

First Experience on Bilirubin Removal with a Hemoadsorption Column (Lixelle®) in a Child with Cardiogenic Liver Injury

Introduction

Hyperbilirubinemia may have deleterious effects on many organs, even after the neonatal age. Blood purification is effective in the treatment of hyperbilirubinemia. Recently some reports suggest the potential role of hemoadsorption columns in this setting.

Methods

We present the case of a 6-year-old child with severe hyperbilirubinemia due to congestive liver dysfunction, complicated by persistent inflammation, immunosuppression and catabolism syndrome (PICS). The patient was treated with a hemoadsorption column (Lixelle®) in combination with continuous veno-venous hemodiafiltration (CVVHDF).

Results

During treatment, a significant and rapid decrease in total bilirubin (TB) and other indices of cholestasis was observed. Furthermore, a progressive reduction in the inflammatory biomarkers (Procalcitonin, C-reactive protein) occurred. These results persisted at the discontinuation of therapy.

Conclusions

To our knowledge this is the first case in which hemoadsorption with the Lixelle® adsorbing column in combination with CVVHDF has been used to manage pediatric hyperbiliribinemia secondary to cardiogenic liver injury.

Preventive effects of the polysaccharide of Larimichthys crocea swim bladder on carbon tetrachloride (CCl4)-induced hepatic damage

The aim of the present study was to determine the preventive effects of the polysaccharide of Larimichthys crocea swim bladder (PLCSB) on CCl4-induced hepatic damage in ICR mice. The in vitro preventive effects of PLCSB on CCl4-induced liver cytotoxic effect were evaluated in BRL 3A rat liver cells using the MTT assay. The serum levels of AST, ALT, and LDH in mice were determined using commercially available kits. The levels of IL-6, IL-12, TNF-α, and IFN-γ were determined using ELISA kits. The pathological analysis of hepatic tissues was performed with H and E staining, and the gene and protein expressions were determined by RT-PCR and Western blotting, respectively. PLCSB (20 μg·mL(-1)) could increase the growth of BRL 3A rat liver cells treated with CCl4. The serum levels of AST, ALT, and LDH were significantly decreased when the mice were treated with two doses of PLCSB, compared with the control mice (P < 0.05). PLCSB-treated groups also showed reduced levels of the serum pro-inflammatory cytokines IL-6, IL-12, TNF-α, and IFN-γ. PLCSB could decrease the liver weight, compared to the CCl4-treated control mice. The histopathology sections of liver tissues in the 100 mg·kg(-1) PLCSB group indicated that the animals were recovered well from CCl4 damage, but the 50 mg·kg(-1) PLCSB group showed necrosis to a more serious extent. The 100 mg·kg(-1) PLCSB group showed significantly decreased mRNA and protein expression levels of NF-κB, iNOS, and COX-2, and increased expression of IκB-α compared with the CCl4-treated control group. In conclusion, PLCSB prevented from CCl4-induced hepatic damage in vivo.

Increased survival despite failure of transplanted human hepatocyte implantation into liver parenchyma of nude mice with repeated lethal Jo2-induced liver deficiency

We recently found that rat hepatocyte transplantation was efficient (liver repopulation: 2.4%) in a sublethal nude mouse model (less than 33% mortality) of repeated liver injury generated using Jo2, a mouse-specific anti-Fas antibody, at sublethal dose of 250 µg/kg for 3 weeks. Genomic analysis of the livers revealed cell cycle blockade and an antiproliferative status of circadian genes, suggesting a selective advantage. By contrast, in the present study, freshly isolated human hepatocyte transplantation performed in the same mouse model resulted in implantation of less than 6,000 cells per liver (about 0.006% repopulation) in all animals. Genomic analysis of nude mouse livers revealed a lack of P21 upregulation, while a signature of stimulation of liver regeneration was observed, including upregulation of early response genes and upregulation of circadian genes. When we translated this sublethal model to a lethal model (65% mortality) by increasing the Jo2 repeated doses to 375 µg/kg, human hepatocyte engraftment was still very low; however, animal mortality was corrected by transplantation (only 20% mortality). Genomic findings in livers from the mice of the lethal Jo2 transplanted group were similar to those of the sublethal Jo2 transplanted group, that is, no selective advantage genomic signature and signature of mouse liver regeneration. In conclusion, transplanted human hepatocytes acted as if they modified nude mouse liver responses to Jo2 by stimulating liver regeneration, leading to an increased survival rate.

Extracorporeal liver perfusion system for artificial liver support across a membrane

BACKGROUND

An extracorporeal porcine liver perfusion (ECPLP) system circumvents the limitations of hepatocyte based bio-artificial liver, but its clinical application has been limited so far due to the potential risk of transmission of porcine endogenous retroviruses. The aim of this study was to develop an ECPLP model that can provide artificial hepatic support across a semi-permeable membrane, which has the potential to block porcine viruses due to its pore size.

MATERIALS AND METHODS

Livers from white landrace pigs were perfused with normothermic oxygenated blood using Medtronic BP560 centrifugal pump (Medtronic, Inc., Minneapolis. MN). This ECPLP system was used to support a "surrogate" patient across the filter Evaclio-EC4A. Function of liver was measured by indocyanine green retention at 15 min (ICGR15). Clearance of galactose, ammonia, and para-aminobenzoic acid infused into the "surrogate" patient circulation was calculated to assess liver support across the membrane. The study was designed as test (n = 15) versus control (n = 5), with control experiments having no liver in the circuit.

RESULTS

For the test experiments, we perfused 15 livers with mean hepatic artery pressure of 87 mm Hg and flows of 1.2 L/min. ICGR15 in test experiments was 11%. Ammonia clearance was 945 mg/min/kg, galactose metabolic rate was 111.7 mg/min/Kg, and the hippurate ratio was 91% in the test. In contrast, the control experiments did not show any significant change in the concentration of any of these compounds.

CONCLUSION

Our ECPLP model was able to provide hepatic support in an experimental setting across a hollow fiber filter. Further work on an anhepatic animal is needed prior to application in human trials.

Prospects for Induced Phiripotent Stem Cell-Derived Hepatocytes in Cell Therapy

Induced pluripotent stem (iPS) cells, first established in 2006, have the same characteristics of self-renew-ability and pluripotency as embryonic stem (ES) cells. iPS cells are inducible from patient-specific somatic cells; therefore, they hold significant advantages for overcoming immunological rejection as well as the ethical issues associated with the derivation of ES cells from embryos. Generation of patient-derived hepatocytes by iPS technology and their use in cell transplantation therapy for patients with liver disease is quite attractive. Here, we discuss recent advances and challenges in hepatocyte differentiation from iPS cells and their utility in cell therapy.

Transplantation of encapsulated hepatocytes during acute liver failure improves survival without stimulating native liver regeneration

The aim of this study was to evaluate the effects of intraperitoneal transplantation of encapsulated human hepatocytes on liver metabolism and regeneration of mice with acute liver failure. Primary human hepatocytes were immortalized using lentiviral vectors coding for antiapoptotic genes and microencapsulated using alginate-polylysine polymers. In vitro, immortalized human hepatocytes showed low, but stable, synthetic and catabolitic functions over time, when compared to primary hepatocytes. In vivo, mice with acute liver failure and transplanted with encapsulated immortalized human hepatocytes had a significantly improved survival and biochemical profile, compared to mice transplanted with empty capsules. Serum levels of cytokines implicated in liver regeneration were lower in mice transplanted with hepatocytes compared to mice receiving empty capsules. This decrease was significant for IL-6 and HGF at 3 h. Measurement of liver regeneration showed no significant difference between mice transplanted with hepatocytes compared to control groups. Intraperitoneal transplantation of encapsulated immortalized hepatocytes significantly improved survival of mice with acute liver failure by providing metabolic support and without modifying liver regeneration. The lower levels of cytokines implicated in liver regeneration suggest that the metabolic support provided by the encapsulated hepatocytes reduced the inflammatory stress on the liver and herein decreased the regenerative trigger on residual hepatocytes. These data emphasize that metabolic function and regeneration of hepatocytes are two distinct aspects that need to be studied and approached separately during acute liver failure.

Is MARS system enough for A. phalloides-induced liver failure treatment?

Patients with Amanita phalloides-induced liver failure (LF) have a high mortality, despite significant advances in intensive care management. Our study evaluated the effect of Molecular Absorbents Recirculating System (MARS) comparative with optimal intensive care (OIC) in adults with this condition, in the absence of liver transplantation (LT). Six consecutive patients (women, range 16-61 years) affected by A. phalloides-induced LF were treated with OIC (3 patients) and MARS (3 patients). Laboratory parameters and hepeatic encephalopaty were evaluated 15 min before and 24 hours following each MARS treatment. Three 6-hour sessions per patient were performed in MARS group, with a statistically significant decrease in ammonia (p value 0.011), alaninaminotransferase (ALT) and prothrombin time (PT) (p value 0.004). Two patients had a significant rebound in bilirubin (+116%; p value 0. 04) 24 hours following MARS. Mortality in MARS group was 66.7%. Survival rate in OIC was 0%. Negative prognostic markers: lack of PT and hepatic encephalopaty improvement, rebound in bilirubin, and delay of MARS therapy initiation. No significant adverse reactions occurred during MARS. MARS is an effective depurative therapy in adults with A. phalloides-induced LF, but alone is not enough. Survival is predicted by the results of the initial MARS, amount of mushroom consumed, and time from toxin exposure.

Long-term outcomes of emergency liver transplantation for acute liver failure

Acute liver failure continues to be associated with a high mortality rate, and emergency liver transplantation is often the only life-saving treatment. The short-term outcomes are decidedly worse in comparison with those for nonurgent cases, whereas the long-term results have not been reported as extensively. We report our center's experience with urgent liver transplantation, long-term survival, and major complications. From 1994 to 2007, 60 patients had emergency liver transplantation for acute liver failure. The waiting list mortality rate was 6%. The mean waiting time was 2.7 days. Post-transplantation, the perioperative mortality rate was 15%, and complications included neurological problems (13%), biliary problems (10%), and hepatic artery thrombosis (5%). The 5- and 10-year patient survival rates were 76% and 69%, respectively, and the graft survival rates were 65% and 59%. Recipients of blood group-incompatible grafts had an 83% retransplantation rate. Univariate analysis by Cox regression analysis found that cerebral edema and extended criteria donor grafts were associated with worse long-term survival. Severe cerebral edema on a computed tomography scan pre-transplant was associated with either early mortality or permanent neurological deficits. The keys to long-term success and continued progress in urgent liver transplantation are the use of good-quality whole grafts and a short waiting list time, both of which depend on access to a sufficient pool of organ donors. Severe preoperative cerebral edema should be a relative contraindication to transplantation.

What clinical alternatives to whole liver transplantation? Current status of artificial devices and hepatocyte transplantation

Shortage of organ donors limits the number of possible liver transplantations. Alternative therapies for treatment of liver failure are currently being developed: (i) extracorporeal artificial liver devices; (ii) bioartificial liver devices using hepatocytes; and (iii) hepatocyte transplantation. The objective of these strategies is to bridge patients with liver failure until a suitable liver allograft is obtained for transplantation or the patient's own liver regenerates sufficiently to resume normal function. In this review, we discuss these strategies and summarize the current status of clinical experience.

Stem cell applications and tissue engineering approaches in surgical practice

There has been an increasing interest in stem cell applications and tissue engineering approaches in surgical practice to deal with damaged or lost tissue. Although there have been developments in almost all surgical disciplines, the greatest advances are being made in orthopaedics, especially in bone repair. Significant hurdles however remain to be overcome before tissue engineering becomes more routinely used in surgical practice.

Cellular Transplantation for Liver Diseases

Presently, the orthotropic liver transplantation (OLT) is still the most effective therapeutic for patients with acute or chronic hepatic failure. However, due to the shortage of donor livers, the number of patients benefited from this approach is limited. Therefore, some alternative modalities have been paid attention for restoring the liver function. The cell transplantation is one of the promising modalities to realize this purpose. The types of cells used in the cell transplantation include syngeneic hepatocytes, allogeneic hepatocytes, immortalized hepatocytes, and stem cells derived heptocytes. The stem cells, especially the adult stem cells from bone marrow, are shown as a promising cell source for liver repopulation. The mesenchymal bone marrow stem cells and embryonic stem cells can be induced to differentiate into the hepatic lineage and might be used in the cell transplantation for liver diseases. Compared to OLT, the advantages of cell-based therapy for liver disease are, but not limited to, less invasive, less expensive, easy manipulated, easy expansion of cells in vitro. Cells can be stored in a cell bank for future use. Though most of the current studies are experimental and animal based, the cellular therapy for liver disease is expected to be an effective alternative in clinical settings in near future.

Acute decompensation and absence of brain and kidney dysfunction predict long-term efficacy of plasma exchange in hyper-bilirubinemic cirrhotic patients awaiting liver transplantation

Various artificial liver support systems are currently used in patients with decompensated chronic liver disease or acute liver failure as a bridge to recovery or to orthotopic liver transplantation (OLT). Between June 2004 and September 2006, 9 subjects were treated with plasma exchange (PE) for acute decompensation on chronic liver disease or chronic decompensation in end-stage liver disease. All of them were awaiting OLT or were listed at the moment of decompensation. Grade II to III hepatic encephalopathy (HE) was present in 4 patients, significant renal dysfunction in 3 patients, and ascites in 6 patients. Baseline serum total bilirubin was 35.1+/-11.2 mg/dL (mean value+/-SD). The patients underwent a mean of 12.1 2-hour exchanges over 1 to 8 weeks. The 3 who recovered were alive after a mean follow-up of 22.7+/-10.3 months. There were 3 patients who underwent transplantation and 3 who died due to liver failure during treatment. Only subjects with acute decompensation and without HE or significant renal dysfunction survived without OLT. PE did not significantly modify the grade of HE or the renal function. PE seemed to be a safe, long-term, effective therapeutic option for acute decompensation among subjects with chronic liver disease without brain or renal dysfunction.

Improved Xenogenic Hepatocyte Implantation into Nude Mouse Liver Parenchyma with Acute Liver Failure when Followed by Repeated Anti-Fas Antibody (Jo2) Treatment

Hepatocyte transplantation is a promising therapy for acute liver failure in humans. Recently, we succeeded in inducing various acute and chronic liver failures in nude mice. Engraftment of transplanted xenogeneic rat hepatocytes, visualized in the host liver by anti-MHC class I immunohistochemistry, revealed that liver repopulation was limited, and equivalent in nude mice with and without acute liver failure. In the present study, acute liver failure was induced in nude mice by a single injection of sublethal anti-Fas antibody Jo2, followed 24 h later by rat hepatocyte transplantation and than by a weekly repeated injection of Jo2. Rat hepatocyte engraftment into the recipient liver parenchyma 3 weeks following hepatocyte transplantation was about sevenfold increased when nude mice were subsequently subjected to weekly repeated Jo2 injection. Genomic analysis of these mice showed an overall transcriptome profile of upregulation of cellular cycle blocking transcripts, activation of liver injury inducing IFN-γ/STAT1 pathway, and circadian transcript signature of antiproliferative cell status compared to mice submitted to hepatocyte transplantation only. The findings of the present study suggest that the induction of cell proliferation blockade in recipient livers could promote sufficient engraftment of transplanted hepatocytes to allow transient or definitive treatment of liver failure in humans.

Differentiation of embryoid-body cells derived from embryonic stem cells into hepatocytes in alginate microbeads in vitro

AIM

Embryonic stem (ES) cells are being widely investigated as a promising source of hepatocytes with their proliferative, renewable, and pluripotent capacities. However, controlled and scalable ES cell differentiation culture into functional hepatocytes is challenging. In this study, we examined the differentiating potential of embryoid-body cells derived from ES cells into hepatocytes in alginate microbeads containing exogenous growth factors in vitro.

METHODS

Embryoid bodies were formed from ES cells by suspension methods. Embryoid bodies cultured for 5 d were treated with trypsin-EDTA. The disaggregated cells were encapsulated in alginate microbeads and stimulated with exogenous growth factors to induce hepatic differentiation. In the course of cell differentiation, cell morphology and viability were observed, and the expression patterns of some genes of the hepatocyte were confirmed by RT-PCR. An immunofluorescence analysis revealed the expression of albumin (ALB) and cytokeratin-18 (CK18). Hepatocyte functional assays were confirmed by the secretion of ALB and urea.

RESULTS

We showed that embryoid-body cells could maintain cell viability in alginate microbeads in vitro. We also found that directed differentiated cells expressed several hepatocyte genes including alpha-fetoprotein (AFP), ALB, Cyp7a1, CK18, transthyretin (TTR) and tyrosine aminotransferase (TAT) and produced ALB and urea in alginate microbeads. The directed differentiated cells expressed ALB and CK18 proteins on d 14. However, embryoid-body cells could not form hepatocytes without exogenous growth factors in alginate microbeads.

CONCLUSION

The differentiation of embryoid-body cells into hepatocytes containing exogenous growth factors in alginate microbeads gives rise to functional hepatocytes and may develop scalable stem cell differentiation strategies for bioartificial livers and hepatocyte transplantation.

Survival of liver failure pigs by transplantation of reversibly immortalized human hepatocytes with Tamoxifen-mediated self-recombination

BACKGROUND/AIMS

Hepatocyte transplantation and bioartificial liver treatment are attractive alternatives to liver transplantation. The availability of well-characterized human hepatocyte lines facilitates such cell therapies.

METHODS

Human hepatocytes were immortalized with a retroviral vector SSR#197 expressing catalytic subunit of human telomerase reverse transcriptase (hTERT) and enhanced green fluorescent protein (EGFP) cDNAs flanked by a pair of loxP recombination targets. Then, Tamoxifen-dependent Cre recombinase was expressed in SSR#197-immortalized hepatocytes. Cre/LoxP recombination was performed in the established cells by simple exposure to 500 nM Tamoxifen for a week. Then, the reverted population of the cells was recovered by EGFP-negative cell sorting and characterized in vitro and in vivo using a pig model of acute liver failure (ALF) induced by d-galactosamine (0.5 g/kg) injection.

RESULTS

A human hepatocyte cell line 16T-3 was established. Reverted 16-T3 cells showed the increased expression of hepatic markers in association with enhanced levels of transcriptional factors. Compared to normal human hepatocytes, albumin production and lidocaine-metabolizing activities of reverted 16-T3 cells were 0.32 and 0.50-fold, respectively. Transplantation of reverted 16T-3 cells significantly prolonged the survival of ALF pigs.

CONCLUSIONS

Here we demonstrate the usefulness of Cre/LoxP -mediated reversible immortalization of human hepatocytes with Tamoxifen-mediated self-recombination.

Somatic cell nuclear transfer in pigs: recent achievements and future possibilities

During the past 6 years, considerable advancement has been achieved in experimental embryology of pigs. This process was mainly generated by the rapidly increasing need for transgenic pigs for biomedical research purposes, both for future xenotransplantation to replace damaged human organs or tissues, and for creating authentic animal models for human diseases to study aetiology, pathogenesis and possible therapy. Theoretically, among various possibilities, an established somatic cell nuclear transfer system with genetically engineered donor cells seems to be an efficient and reliable approach to achieve this goal. However, as the result of unfortunate coincidence of known and unknown factors, porcine embryology had been a handicapped branch of reproductive research in domestic animals and a very intensive and focused research was required to eliminate or minimise this handicap. This review summarises recent achievements both in the background technologies (maturation, activation, embryo culture) and the actual performance of the nuclear replacement. Recent simplified methods for in vivo development after embryo transfer are also discussed. Finally, several fields of potential application for human medical purposes are discussed. The authors conclude that although in this early phase of research no direct evidence can be provided about the practical use of transgenic pigs produced by somatic cell nuclear transfer as organ donors or disease models, the future chances even in medium term are good, and at least proportional with the efforts and sums that are invested into this research area worldwide.

Acute liver failure due to leptospirosis successfully treated with MARS (molecular adsorbent recirculating system) dialysis

BACKGROUND

Leptospirosis is a re-emerging infectious disease, which may lead to multiple organ failure (MOF)and death.

CASE PRESENTATION

We report the first case of severe leptospirosis complicated with acute renal and liver failure, successfully treated with albumin dialysis--molecular adsorbent recirculating system (MARS). Despite antibiotic therapy, optimum medical supportive treatment and timely initiated haemodialysis, the outcome was complicated by severe liver failure: hepatic encephalopathy grade III, hypoglycemia, prominent hyperbilirubinemia (TBIL 31.3 mg/dl, DBIL 28.6 mg/dl)and hepatic cytolysis (ALT 535 IU/l, AST 179 IU/l) and prolongation of the prothrombine time (68.4 sec). The patient underwent two sesions of albumin dialysis with the MARS procedure with complete recovery of hepatic and renal function.

CONCLUSION

Albumin dialysis may confer a significant survival benefit on patients with leptospirosis-induced acute liver failure (ALF).

Molecular adsorbent recirculating system (MARS) application in liver failure: clinical and hemodepurative results in 22 patients

PURPOSE

Acute liver failure (ALF) and acute on chronic liver failure (ACLF) still show a poor prognosis. MARS was used in 22 patients with ALF or ACLF to prolong patient survival for liver function recovery or as a bridge to transplantation.

DESIGN

Evaluation of depurative efficiency, biocompatibility, hemodynamics, encephalopathy (HE) and clinical outcome.

PROCEDURES

During 71 five-hour sessions we evaluated (0', 60', 120', 180', 240', 300'): bilirubin, ammonia, cholic acid (CCA), chenodeoxycholic acid (CCDCA), leukocytes, platelets, hemoglobin and mean arterial pressure (MAP). Serum creatinine, electrolytes, cardiac output, cardiac index (bioimpedence) and HE (West Haven Criteria score) were evaluated at 0' and 300'. STATISTICAL METHODS AND OUTCOME MEASURES: Student's t-test for pre- vs. end-session values was used. For bilirubin and ammonia the correlation test was made between pre- and end-session values and between pre-session values and removal rates (RRS).

MAIN FINDINGS

Survival was 90.9% at 7 days, 40.9% at 30 days. Pre- vs. end-session: bilirubin from 37.2 +/- 12.5 mg/dL to 24.9 +/- 8.9 mg/dL (p < 0.01), ammonia from 88.0 +/- 60.4 micromol/L to 43.6 +/- 32.9 micromol/L (p < 0.01), CCA from 42.8 +/- 21.0 micromol/L 18.2 +/- 9.8 micromol/L (p < 0.01), CCDCA from 26.3 +/- 6.3 micromol/L to 15.7+/-7.6 micromol/L (p<0.01). The correlation test between pre-session values of bilirubin and ammonia vs. RR S was respectively 0.32 (p = 0.01) and 0.30 (p = 0.04). Leukocytes, platelets and hemoglobin remained stable. MAP increased from 82.0 +/- 12.0 mmHg to 87.0 +/- 13.0 mmHg (p < 0.05), West Haven Criteria score decreased from 2.7 +/- 0.7 to 0.7 +/- 0.7 (p < 0.001).

CONCLUSION

MARS treatment led in all patients to an improvement of clinical, hemodynamic and neurological conditions, with significant reduction in the hepatic toxins blood level. Treatment biocompatibility and tolerance were satisfactory.

Etiological investigation of fatal liver failure during the course of chronic hepatitis B in southeast China

BACKGROUND

The purpose of this study was to clarify the relationships between patients who had fatal liver failure during the course of chronic hepatitis B and those who were also superinfected with hepatitis A, C, D, or E virus, as well as their hepatitis B virus e system status, so that suitable measures could be adopted to decrease the mortality of patients with chronic hepatitis B.

METHODS

This study detected superinfections of hepatitis A, C, D, or E virus and the hepatitis B virus e system status in cases of fatal liver failure during the course of chronic hepatitis B by enzyme-lined immunosorbent assay.

RESULTS

The frequency of superinfections of hepatitis A, C, D, and E virus was 1.4% (4/282), 6.4% (18/282), 1.8% (5/282), and 28.4% (80/282), respectively, overall, 37.9% (107/282). Hepatitis E was prominent and steady in superinfection rates during the past 12 years. In 62.1% (175/282) of patients, the causes of fatal liver failure were not clear. The serological status frequency of HBeAg(+) and anti-HBe(-), HBeAg(-) and anti-HBe(-), and HBeAg(-) and anti-HBe(+) was 20.6% (22/107), 23.4% (25/107), and 56.1% (60/107), respectively, in the group with superinfections of hepatitis A, C, D, or E virus and 31.4% (55/175), 21.1% (37/175), and 47.4% (83/175), respectively, in the group in which causes were not clear. The serological status HBeAg(+) and anti-HBe(-) was more frequent in the group in which causes were not clear than in the group with superinfections of hepatitis A, C, D, or E virus (P < 0.05). Statistically, there were no differences (P > 0.05) between the serological status HBeAg(-), anti-HBe(-) and HBeAg(-), anti-HBe(+) between the two groups.

CONCLUSIONS

These results suggest that superinfection (107/282) is an important factor in fatal liver failure. The mortality of chronic hepatitis B can be decreased by strict food sanitation and the use of safe blood products. There were no significant relationships between hepatitis B e antigen seroconversion and fatal liver failure during the course of chronic hepatitis B.

Review article: non-biological liver support in liver failure

Liver failure, whether acute or acute-on-chronic, remains an important cause of morbidity and mortality. The lack of liver detoxification, metabolic and regulatory functions of the liver leads to life-threatening complications, such as renal failure, altered immune response, hepatic coma and systemic haemodynamic dysfunction, eventually culminating in multiorgan failure. Current medical therapy involves the management of the precipitating event and treatment of complications until the liver eventually recovers, leaving us with no other treatment options than transplantation if these attempts fail. However, the shortage in cadaveric organs and other transplant-related problems, have prompted the need for alternative methods to provide liver support. As liver failure is often potentially reversible, considerable effort has been invested in the development of liver support systems. Currently, most of the experience is available for non-biological support systems. They represent the focus of this review, which aims to define the goals of liver support, to describe the design of the different existing devices and to analyse the available data to determine their current status in the management of patients with liver failure.

Human hepatocyte transplantation for acute liver failure: state of the art and analysis of cell sources

Liver transplantation is the only treatment available for acute liver failure. However, mortality rates remain high because of the shortage of donor organs. Indeed up to 20% of patients with acute liver failure may survive without transplantation. In the last two decades, research has focused on the development of alternative or supportive measures to deal with acute liver failure; one of the most studied is hepatocyte transplantation, because it is thought that the function of the liver can only be replaced with a biological substrate characterized by functioning liver cells. Hepatocyte transplantation has been successful in many animal models of acute liver failure, although only several clinical attempts have been made in humans with encouraging but not yet convincing results, mainly because of the lack of a reliable source of live liver cells. Allogenic and xenogenic fresh or cryopreserved hepatocytes have been tested. Recent research has focused on fetal hepatocytes and progenitor liver cells of both hepatic and bone marrow origin. The ability to preserve and bank human hepatocytes would allow pooling of cells from multiple donors to increase the numbers for transplantation. The development of a reliable and large-scale available source of live liver cells would probably have a major impact on the introduction of hepatocyte transplantation in clinical practice.

[Artificial liver support systems: update on albumin dialysis (MARS)]

Mortality among patients with liver insufficiency continues to be unacceptably high. The prognosis of patients with acute episodes of chronic liver insufficiency is almost as poor as that of patients with acute liver failure. Therefore, systems that support liver function, either until liver transplantation can be performed or until resolution of the situation before acute injury occurs, are essential. Albumin dialysis is a system of artificial liver support that allows detoxification of albumin-related and hydrosoluble substances, thus maintaining the patient's homeostasis. Current clinical experience of this therapy is still limited, although beneficial effects on clinical, laboratory and hemodynamic parameters have been demonstrated. Multicenter, controlled trials to evaluate the effect of this therapy on survival in distinct diseases are needed.

Technology insight: liver support systems

Emergency orthotopic liver transplantation (OLT) is currently the only standard treatment for fulminant hepatic failure (FHF). The waiting time for transplantation can exceed a week-using a liver assist device to bridge patients with FHF to OLT might therefore decrease the mortality rate. Several liver support systems have been described, but no system has gained FDA approval or widespread clinical acceptance. Although the results of many experimental and clinical trials are encouraging, the field is still in its initial stages. Using nonbiologic liver support is based on the assumption that several toxins that cause hepatic coma can be removed from the circulation by blood or plasma sorption methods. As these toxins could be involved in many FHF complications recovery without the need for transplantation is the ultimate aim. Biologic liver support uses xenogeneic livers or hepatocytes to support the failed human liver, exploiting biological cell functions, namely detoxification, metabolism, and biosynthesis. The classical nonbiologic dialysis methods could decrease mortality in patients with acute-on-chronic liver failure, but definitive conclusions are impossible to draw because of the small number of patients studied and inadequate follow-up. Larger studies performed in specialty centers should provide conclusive data about the role of the bioartificial liver support system as a possible universal bridge to OLT. This article presents an overview of published experience with liver support systems since the 1960s.

Characteristics of hepatocytes derived from early ES cells and treatment of surgically induced liver failure rats by transplantation

BACKGROUND

Although liver transplantation has become a standard therapy for diseases such as fulminant hepatitis and cirrhosis, the lack of donor organs remains a major problem. One solution is the development of transplantable hepatocytes. The metabolic characteristics as well as function and adaptation of hepatocytes (R-EES-hep cell) derived from rat early embryonic stem cells were examined after transplantation into rats with surgically induced liver failure.

METHODS

Rat hepatocyte cell lines were established from early embryonic stem cells cultured in the presence of embryotrophic factors by colony cloning methods. The cell lines were established from two cell embryos taken from spontaneous dwarf rats using the novel method of Ishiwata et al. Morphologic differentiation as well as albumin and bilirubin production were observed by immunostaining. R-EES-hep cells were transplanted into the spleens of 90% hepatectomized, surgically induced liver failure rats to analyze survival rates.

RESULTS

When cultured in type I collagen gel the cells formed cordlike structures resembling the liver. Both albumin and bilirubin production were observed when transplanted; the spleen was converted into a liver-like structure with prolonged survival of the 90% hepatectomized rats for up to 3 months up to the time of killing.

CONCLUSIONS

R-EES-hep cells showed many of the distinctive metabolic characteristics of the liver. These cells may be efficient for further research and application for hepatic cell transplantation to treat liver insufficiency patients and as biologic artificial organs.

Experimental models of acute and chronic liver failure in nude mice to study hepatocyte transplantation

Although hepatocyte transplantation is a promising therapy for acute liver failure in human, there is still a lack of animal models suffering from hepatic injury in which the benefits of hepatocyte transplantation could be evaluated solely, without the bias caused by immunosuppression. As a consequence, the aim of the study was first to develop reproducible models of partial hepatectomy and of thioacetamide (TA)- or Jo2-induced acute liver failure in nude mice. Chronic liver disease was also investigated by repeated injections of sublethal doses of thioacetamide. Survival rates, routine histologic observations, alanin aminotransferase sera content, Ki67, and caspase 3 immunodetection were investigated both after 40% partial hepatectomy and after toxic-induced damages. Liver injuries were more severe and/or precocious in nude mice than in Balb/c mice for a given treatment with a maximum of acute injury obtained 24 h after single toxic injection, and were found to be transitory and reversible within 10 days. Toxics induced apoptosis followed by necrosis, confirming recent published data. Onset of fibrosis leading to reproducible chronic cirrhosis in nude mice correlated with increasing number of Ki67-positive cells, indicating that high levels of cell proliferation occurred. Chronic cirrhosis progressively reversed to fibrosis when the treatment ceased. Preliminary results demonstrated that engrafted xenogeneic hepatocytes could be detected in the host liver by anti-MHC class I immunohistochemistry. Fractions enriched in 2n or 4n hepatocytes by cell sorting using a flow cytometer were equivalent to the unpurified fraction in terms of engraftment in control nude mice or in nude mice subjected to PH. However, in mice suffering from liver injury 24 h after Jo2 or TA treatment, the engraftment of 2n hepatocytes was about twice that of an unpurified hepatocyte population or of a population enriched in 4n hepatocytes.

Effects of plasma from patients with fulminant hepatic failure on function of primary rat hepatocytes in three-dimensional culture

BACKGROUND/AIM

As biotechnology continues to advance, a bioartificial liver is expected to be developed for the treatment of patients with fulminant hepatic failure (FHF) whose liver dysfunction is potentially reversible or for providing liver support as a bridge to liver transplantation. While monolayer-cultured hepatocytes rapidly lose their capacity to express many liver-specific functions over time when cultured, spherical-shaped hepatocytes in three-dimensional culture with the use of extracellular matrix components sustain long-term survival by maintaining differentiated hepatocyte functions. The aim of this study was to investigate whether sufficient functions of viable spherical-shaped hepatocytes could be maintained in plasma of patients with FHF in order to use these cells in an extracorporeal system.

METHODS

Hepatocyte functions were evaluated under monolayer or three-dimensional culture in FHF plasma.

RESULTS

Primary rat hepatocytes on poly-N-p-vinylbenzyl-D-lactonamide (PVLA) formed spheroids even in FHF plasma and maintained their spherical shapes in FHF plasma as long as in medium. Spherical-shaped hepatocytes on PVLA cultured in FHF plasma showed higher activity in albumin secretion, urea formation, and gluconeogenesis than those in normal human plasma or medium. As being cultured in medium, hepatocytes on PVLA cultured in plasma were also superior to cells on collagen in regard to albumin secretion, amino acid metabolism, and gluconeogenesis.

CONCLUSIONS

These findings demonstrated that FHF plasma is not toxic to rat hepatocyte spheroids and that hepatocyte spheroids have potential use in the development of a bioartificial liver.

Xenotransplantation: an update on recent progress and future perspectives

Currently, the number of patients awaiting transplantation is continuously increasing, and shortage of available deceased organ donors is the major limitation for organ and cell allotransplantation. Research to develop alternative sources of tissues is ongoing and xenogeneic organs or cells represent an attractive solution. This review focuses on recent progress achieved in this field, including the development of newly genetically modified animal donors and new immunosuppressive approaches. As xenotransplantation is moving closer to clinical application, future perspectives must establish guidelines to ensure that future clinical trials are carried out ethically and safely.

Molecular Adsorbent Recirculating System Treatment for Acute Hepatic Failure in Patients With Hepatitis B Undergoing Chemotherapy for Non-Hodgkin’s Lymphoma

Hepatitis B virus (HBV) is a serious cause of morbidity and mortality in hepatitis B surface (HBsAg) antigen-positive patients treated with chemotherapy. Because the hepatitis is related to HBV virological reactivation, application of effective antiviral therapy, such as Lamivudine, has been attempted. Despite the use of these antiviral agents at the time of clinical hepatitis, some HBsAg-positive patients still develop hepatic failure and die. We used the Molecular Adsorbent Recirculating System (MARS) (MARS Monitor; Teraklin AG, Rostock, Germany) to treat 5 HBsAg-positive lymphoma patients with acute hepatic failure due to chemotherapy despite lamivudine treatment. Before and after each treatment we monitored the parameters of neurological status (EEG, cerebral CT and Glasgow coma score), hemodynamic parameters, acid-base equilibrium and blood gases as well as hepatic and renal function. The inclusion criteria were these of the King's College Hospital. Statistical analysis by Student t method showed significant results (P < .01). Three of 5 patients are alive without signs of reactivation of viral or hematological diseases at 1 year follow-up. The 2 patients died because MARS treatment was started too late, with Glascow coma score grade IV, hemodynamic instability, and mechanical ventilator assistance. Despite the limited number of cases, we believe that MARS can be applied to patients with a high tolerance and yield good results, but the treatment has to start at the first signs of hepatic failure.

Emerging indications for albumin dialysis

The accumulation of albumin-bound toxins in liver failure is believed to be responsible for the development of associated end-organ dysfunctions (kidney, circulation, brain). Albumin dialysis utilizes the scavenging functions of albumin for the removal of toxins. The Molecular Adsorbents Recirculating System (MARS) is one such extracorporeal liver support device where blood is dialyzed across an albumin-impregnated membrane against 20% albumin. Charcoal and anion exchange resin columns in the circuit cleanse and regenerate the albumin dialysate. Clinical studies in the last decade have demonstrated proven reduction in hyperbilirubinemia, along with an improvement in encephalopathy in liver failure patients, as well as apparent improvement in survival. Some studies have also reported improvement of systemic hemodynamics and renal function in these patients. Amelioration of intractable pruritus and treatment of toxicities with albumin-bound substances are some of the newer indications emerging. However, the specific underlying pathophysiological mechanisms are still not clear. Two other systems based on the removal of albumin-bound toxins, the Prometheus (using the principle of fractionated plasma separation and adsorption [FPSA]), and the single pass albumin dialysis (SPAD) are also currently under development but available clinical data are limited.

Tissue engineering in surgery

The demands for repair and renewal of worn out or injured human tissue continue to increase and it is now apparent that this demand cannot be met from human donors. A partial solution may be found in living related and trans-species transplantation but these approaches invoke the problems of disease transfer and ethical dilemmas. Tissue engineering is a new technology that seeks to meet these increasing demands by utilising novel cell culture methods in vitro to provide tissue replacements in vivo. This article reviews the current state of tissue engineering and its potential for use in surgery.

Fulminant hepatic failure

Fulminant hepatic failure is a rapidly progressive and often fatal syndrome, and the only definitive treatment is liver transplantation. However, given the scarcity of available grafts, the mainstay of therapy remains supportive care until there is spontaneous recovery or until a suitable donor liver becomes available. After initial assessment and stabilization, patients should be transferred to the nearest liver transplant center as soon as possible, as they can deteriorate rapidly. All patients with fulminant hepatic failure must be monitored closely and treated for hepatic encephalopathy, coagulopathy, gastrointestinal bleeding, renal failure, cerebral edema, and metabolic derangement.

Liver transplantation for fulminant hepatic failure: experience with more than 200 patients over a 17-year period

OBJECTIVE

To analyze outcomes after liver transplantation (LT) in patients with fulminant hepatic failure (FHF) with emphasis on pretransplant variables that can potentially help predict posttransplant outcome.

SUMMARY BACKGROUND DATA

FHF is a formidable clinical problem associated with a high mortality rate. While LT is the treatment of choice for irreversible FHF, few investigations have examined pretransplant variables that can potentially predict outcome after LT.

METHODS

A retrospective review was undertaken of all patients undergoing LT for FHF at a single transplant center. The median follow-up was 41 months. Thirty-five variables were analyzed by univariate and multivariate analysis to determine their impact on patient and graft survival.

RESULTS

Two hundred four patients (60% female, median age 20.2 years) required urgent LT for FHF. Before LT, the majority of patients were comatose (76%), on hemodialysis (16%), and ICU-bound. The 1- and 5-year survival rates were 73% and 67% (patient) and 63% and 57% (graft). The primary cause of patient death was sepsis, and the primary cause of graft failure was primary graft nonfunction. Univariate analysis of pre-LT variables revealed that 19 variables predicted survival. From these results, multivariate analysis determined that the serum creatinine was the single most important prognosticator of patient survival.

CONCLUSIONS

This study, representing one of the largest published series on LT for FHF, demonstrates a long-term survival of nearly 70% and develops a clinically applicable and readily measurable set of pretransplant factors that determine posttransplant outcome.

New approach for the establishment of an hepatocyte cell line derived from rat early embryonic stem cells

A cell line with the characteristics of hepatocytes was established from rat early embryonic stem cells (REES). This cell line was established using a new novel method of Ishiwata et al. from two cell embryos taken from the spontaneous dwarf rat (SDR). The hepatocyte cell line (REES-hep) was instituted from dark red colored tissue in embryos during embryogenesis using REES cell line cultured in the presence of embryotrophic factors. These cell lines were cultured with DMEM/F12 medium supplemented 10% FBS and 1 ng/ml of LIF. They were found to maintain their diploid state, were characterized with 42 normal chromosomes and proliferated to confluence; contact inhibition was also present. These cells produced albumin when cultured using a collagen sponge gel system and reconstructed in a funicular form resembling the cell cords of liver. The cells also produced albumin and bilirubin when transplanted into the spleen of SDR Reconstruction of a REES-hep cell line from early embryonic stem cells should help in treating hepatic insufficient patients. It will be valuable for further research, as an introduction to cell transplantation and application for use in a bio-hybrid typed liver apparatus.