Acute liver failure

Liver transplantation()

Orthotopic liver transplantation (OLT) involves the substitution of a diseased native liver with a normal liver (or part of one) taken from a deceased or living donor. Considered an experimental procedure through the 1980s, OLT is now regarded as the treatment of choice for a number of otherwise irreversible forms of acute and chronic liver disease.The first human liver transplantation was performed in the United States in 1963 by Prof. T.E. Starzl of the University of Colorado. The first OLT to be performed in Italy was done in 1982 by Prof. R. Cortesini. The procedure was successfully performed at the Policlinico Umberto I of the University of Rome (La Sapienza).The paper reports the indications for liver transplantation, donor selection and organ allocation in our experience, surgical technique, immunosuppression, complications and results of liver transplantation in our center.

Construction and transplantation of an engineered hepatic tissue using a polyaminourethane-coated nonwoven polytetrafluoroethylene fabric

BACKGROUND

Acute liver failure (ALF) is a serious condition that has a high mortality rate. Construction of an efficient culture and transplantation engineering system of hepatic tissue is an important approach to treat patients suffering from ALF to provide short-term hepatic support until the damaged liver spontaneously recovers or a donor liver becomes available for transplantation. Here, we evaluate the construction and transplantation of an engineered hepatic tissue (EHT) using primary isolated hepatocytes cultured onto polyaminourethane (PAU)-coated, nonwoven polytetrafluoroethylene (PTFE) fabric.

METHODS

The isolated hepatocytes cultured onto PAU-coated PTFE fabric were able to adhere and spread over the individual fibers of the net and formed hepatic clusters after 3 days, such clusters revealed Gap junctions and well-developed bile canaliculi.

RESULTS

When PAU-coated PTFE was utilized, ammonia-, and diazepam- metabolizing capacities and albumin production ability were significantly increased compared with collagen control. To test the function of this hepatic tissue in vivo, we transplanted a nonwoven PAU-coated PTFE fabric inoculated with one million hepatocytes on the surface of the spleen of Balb/c mice suffering from ALF induced by 90% hepatectomy, and found that this EHT prolonged the survival of liver failure-induced mice without adverse effects. Ultrastructure analyses showed good attachment of the cells on the surface of PTFE fabric and strong albumin expression seven days after the newly formed hepatic tissue was transplanted.

CONCLUSION

We have here demonstrated the efficient construction and transplantation of hepatic tissue using primary hepatocytes and PAU-coated PTFE fabric.

An inhibitor of c-Jun NH2-terminal kinase, SP600125, protects mice from D-galactosamine/lipopolysaccharide-induced hepatic failure by modulating BH3-only proteins

Fulminant hepatic failure (FHF) is a dramatic clinical syndrome characterized by massive hepatocyte apoptosis and very high mortality. The c-Jun-N-terminal kinase (JNK) pathway is an important stress-responsive kinase activated by several forms of liver injury. The aim of this study is to assess the role of JNK during D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury, an experimental model of FHF, using SP600125, a small molecule JNK-specific inhibitor. Mice were given an intraperitoneal dose of GalN (800 microg/g body weight)/LPS (100 ng/g body weight) with and without subcutaneous SP600125 (50 mg/kg body weight) treatment (at 6 and 2 h before and 2 h after GalN/LPS administration). GalN/LPS treatment induced sustained JNK activation. Administration of SP600125 diminished JNK activity, suppressed lethality and the elevation of both serum alanine aminotransferase and aspartate aminotransferase, but had no effect on serum tumor necrosis factor-alpha, and reduced hepatocyte apoptosis after GalN/LPS administration. In support of the role of JNK in promoting the mitochondria-mediated apoptosis pathway, SP600125 prevented cytochrome c release, caspase-9 and caspase-3 activity. Moreover, SP600125 downregulated the mRNA and protein expression of Bad in the early periods following GalN/LPS injection and prevented Bid cleavage in the late periods. These results confirm the role of JNK as a critical apoptotic mediator in GalN/LPS-induced FHF. SP600125 has the potential to protect FHF by downregulating Bad and inhibiting Bid cleavage.

Liver support technology--an update

BACKGROUND

Currently, there is no direct treatment for hepatic failure, and patients must receive a transplant or endure prolonged hospitalization, with significant morbidity and mortality. Because of the scarcity of donor organs, liver support strategies are being developed with the aim of either supporting patients with borderline functional liver cell mass until an appropriate organ becomes available for transplantation or until their livers recover from injury.

METHODS

A literature review was performed using MEDLINE and library searches. Only major blood detoxification/purification devices and cell-based techniques are included in this review.

RESULTS

Currently, a number of blood purification systems and devices utilizing viable liver cells are in various stages of clinical development. Non-biological systems include plasma exchange, albumin dialysis, hemo(dia)filtration, and sorbent-based devices (charcoal, resin). These systems are able to remove toxins of hepatic failure, and their utility is limited by their inability to provide missing liver-specific functions. In contrast, hepatocyte-based devices are able to provide whole liver functions, including detoxification, biosynthesis, and biotransformation. Molecular adsorbent recycling system (MARS) blood detoxification system has been tested in thousands of patients, but additional well-conducted controlled studies are warranted to better define the role of MARS in the treatment of patients with acute hepatic failure and acute exacerbation of chronic liver disease. HepatAssist was tested in a phase II/III controlled clinical trial that demonstrated safety and proof of concept for use of biological liver support systems to improve patient survival in acute hepatic failure.

CONCLUSIONS

Developing an effective liver assist technology has proven difficult, because of the complexity of liver functions that must be replaced, as well as heterogeneity of the patient population. Non-biological systems may have a role in the treatment of specific forms of liver failure where the primary goal is to provide blood detoxification/purification. Biological systems appear to be useful in treating liver failure where the primary objective is to provide whole liver functions which are impaired or lost. It is suggested that there will be a role for hybrid liver support systems that offer liver cell therapy and various forms of blood purification (sorption, hemofiltration and diafiltration) to treat patients with specific forms of liver failure at various stages of their illness.

Porcine model of auxiliary partial orthotopic liver transplantation for acute liver failure

BACKGROUND

Auxiliary partial orthotopic liver transplantation (APOLT) has been an effective alternative in acute liver failure (ALF), but clinically several problems remain to be resolved. Thus, we attempt to establish an APOLT model for ALF using a large animal and demonstrate the validity of our model.

METHODS

In experiment 1, we created an animal model of ALF using pig. ALF was induced by resection of 70% of the whole liver under total hepatic vascular exclusion (THVE). The duration of ischemia was 90 minutes. In experiment 2, we tried to make an APOLT model by using this ALF model as a recipient. That is, during 90 minutes of THVE, 70% hepatectomy and subsequent partial orthotopic transplantation was completed.

RESULTS

In experiment 1, six of seven pigs died within three days with jaundice and massive ascites. Based on microcirculatory disturbance of the remnant liver and hepatocellular necrosis, 70% hepatectomy with 90 minutes of THVE was considered a proper model of ALF. In experiment 2, six out of seven APOLT model animals survived more than four days. T. Bil levels in the APOLT model remained consistently within the normal range throughout the observation period. In immunohistochemistry, several labeled nuclei stained with Ki67 were identified in native liver of the APOLT model.

CONCLUSIONS

This APOLT procedure provided temporary liver function support and enabled the recipient to survive until the failing native liver had regenerated. Our APOLT model could be suitable and useful for understanding the role of APOLT in ALF.

Acute lymphoblastic leukemia presenting in fulminant hepatic failure

A previously healthy 4-year-old boy was admitted because of acute liver failure. He was icteric, lethargic, had elevated ammonia and abnormal liver function tests. Serology was negative for viral hepatitis. There was no history of hepatotoxic drugs. Family history was unremarkable. The child was taken to the operating room for a living-related hepatic transplant. Frozen section showed massive hepatic leukemic infiltration and hepatocellular necrosis. Bone marrow aspiration confirmed the diagnosis of acute lymphoblastic leukemia (ALL). Transplant was withheld and chemotherapy was attempted. He died the following day due to systemic leukemic infiltration, cerebral edema, and severe anoxic ischemic encephalopathy.

Reversal of mouse hepatic failure using an implanted liver-assist device containing ES cell-derived hepatocytes

Severe acute liver failure, even when transient, must be treated by transplantation and lifelong immune suppression. Treatment could be improved by bioartificial liver (BAL) support, but this approach is hindered by a shortage of human hepatocytes. To generate an alternative source of cells for BAL support, we differentiated mouse embryonic stem (ES) cells into hepatocytes by coculture with a combination of human liver nonparenchymal cell lines and fibroblast growth factor-2, human activin-A and hepatocyte growth factor. Functional hepatocytes were isolated using albumin promoter-based cell sorting. ES cell-derived hepatocytes expressed liver-specific genes, secreted albumin and metabolized ammonia, lidocaine and diazepam. Treatment of 90% hepatectomized mice with a subcutaneously implanted BAL seeded with ES cell-derived hepatocytes or primary hepatocytes improved liver function and prolonged survival, whereas treatment with a BAL seeded with control cells did not. After functioning in the BAL, ES cell-derived hepatocytes developed characteristics nearly identical to those of primary hepatocytes.

A novel plasma filtration therapy for hepatic failure: preclinical studies

There is a need to develop artificial means of liver replacement and/or assistance with the aim of either supporting patients with borderline functional liver cell mass until their liver regenerates, or until a donor liver becomes available for transplantation. Selective plasma filtration is a novel approach to blood purification therapy designed to reduce the level of circulating toxins of hepatic and renal failure, mediators of inflammation and inhibitors of hepatic regeneration. The results of preclinical studies indicate that treatment of pigs with experimentally-induced fulminant hepatic failure is safe and effective in extending survival time and arresting brain swelling. In addition, the amount of ammonia, aromatic amino acids, IL6, TNFalpha and C3a removed during the 6-h treatment in the present study was higher by 34% to 175% than the total plasma content of those substances at the start of therapy.

Molecular adsorbent recirculating system dialysis in patients with acute liver failure who are assessed for liver transplantation

OBJECTIVE

To assess the usefulness of dialysis with the molecular adsorbent recirculating system (MARS) in patients with acute liver failure who fulfil criteria for liver transplantation.

DESIGN

Observational cohort study.

SETTING

ICU at a liver transplantation centre.

PATIENTS

Twenty-two patients (23 episodes) received MARS dialysis. They were either listed for LT (n=14), delayed (n=1), or not listed (contra-indication, n=7).

INTERVENTIONS

A total of 56 MARS treatments (median per patient 2; mean duration 7.6+/-2.6h) were performed on haemodialysis.

MEASUREMENTS AND RESULTS

Clinical and biological variables were assessed before and 24[Symbol: see text]h after MARS therapy. The rate of recovery of liver function without transplantation was compared with an expected rate and survival was analysed. Following MARS dialysis, we observed an improvement in the grade of hepatic encephalopathy (P=0.02) and the Glasgow coma score (P=0.02), a decrease in conjugated bilirubin (P=0.05) and INR (P=0.006), and an increase in prothrombin index (P=0.005). Overall, liver function improved in seven patients (32%): four listed patients in whom transplantation could be avoided and three patients among those not listed due to contra-indications. The transplant-free recovery rate in listed patients was 29% (vs. expected 9%, P=0.036). Listed patients (n=14) had a higher 30-day survival rate [86% (12/14) vs 38% (3/8), P=0.05] and a higher long-term survival rate (P=0.02).

CONCLUSIONS

A statistically significant improvement of liver function was observed after MARS therapy. Transplant-free recovery was more frequent than expected. The apparent benefit of MARS dialysis to treat acute liver failure needs to be confirmed by a controlled study.

Intensive care unit management of fulminant hepatic failure

OBJECTIVE

The aim of this open/retrospective study was to evaluate the outcomes of intensive care unit patients treated for fulminant hepatic failure (FHF) for predictive indices.

METHODS

All patients were recovered in the intensive care units with a diagnosis of FHF. We considered three groups of patients: (1) survivors, deceased, and transplanted.

SUBJECTS

All patients were fully screened, including liver function indices such as AST, ALT, total and bound bilirubin, albumin and pre-albumin, factors 5 and 7, alpha fetal protein (alpha-PP), other coagulation tests (PT, aPTT, INR, ATIII), and renal function (BUN and creatinine) parameters. For each patient Apache II score was calculated upon admission to the intensive care unit.

RESULTS

Apache II score showed efficacy. alpha-PP increased in both surviving and deceased, but not in the transplanted group. After intensive care unit admission, AST and ALT peaks were higher in the deceased DP than in the transplanted group. The INR value at the third day after ICU admission improved in the survivors compared with the other two cohorts. Factor 5 levels were lower among patients undergoing transplantation, but increased in the other two groups. The prognosis was strictly dependent upon the development of renal failure.

CONCLUSION

The Apache II score was a sensitive predictive index for outcome. alpha-PP and factor 5 were not related to outcome, but useful for decision making when determining potential liver transplantation. INR can be used as a prognostic index. Intensive treatment beforehand is of primary importance to prevent multiple organ failure.

1H NMR spectroscopy for the prediction of therapeutic outcome in patients with fulminant hepatic failure

A high-resolution (1)H NMR study of serum and urine of fulminant hepatic failure patients (n = 22) [surviving (n = 12) and non-surviving (n = 10)] is reported. Glutamine in serum and urine glutamine:creatinine ratio were higher in non-surviving patients compared with surviving patients [serum glutamine, 3.08 (1.68-7.11) vs 0.56 (0.34-0.99) mM, median and range; p = 0.0001 and urine glutamine:creatinine ratio, 1.72 (0.24-7.76) vs 0.39 (0.1-0.84), p = 0.1], and urine urea:creatinine ratio was higher in surviving patients compared with non-surviving patients [10.83 (0.2-22.6) vs 2.09 (0.96-4.0), p = 0.002]. On the other hand, no significant differences were found in the conventionally employed clinical parameters such as serum alanylaminotransferase, aspartylaminotransferase and bilirubin except prothrombin time (p = 0.02). The difference in serum glutamine and urine urea was significant in the two categories of patients and distinctly different values of serum glutamine for both the categories of patients correctly predicted the outcome. These results promise immense potential for NMR spectroscopy in rapidly deciding on the need for advanced therapeutic intervention such as artificial liver support or emergency liver transplantation in FHF.

Acute liver failure due to natural killer-like T-cell leukemia/lymphoma: A case report and review of the Literature

Acute liver failure (ALF) is a medical emergency requiring immediate evaluation for liver transplantation. We describe an unusual case of a patient who presented with ascites, jaundice, and encephalopathy and was found to have ALF due to natural killer (NK)-like T cell leukemia/lymphoma. The key immunophenotype was CD2+, CD3+, CD7+, CD56+. This diagnosis, which was based on findings in the peripheral blood and ascitic fluid, was confirmed with liver biopsy, and was a contraindication to liver transplantation. A review of the literature shows that hematologic malignancies are an uncommon cause of fulminant hepatic failure, and that NK-like T-cell leukemia/lymphoma is a relatively recently recognized entity which is characteristically CD3+ and CD56+. This case demonstrates that liver biopsy is essential in diagnosing unusual causes of acute liver failure, and that infiltration of the liver with NK-like T-cell lymphoma/leukemia can cause acute liver failure.

Global distribution of infectious diseases requiring intensive care

This article describes infectious diseases that are of special importance to intensivists. The emphasis on epidemiology notwithstanding, it also addresses clinical, diagnostic, and treatment issues related to each infection described. The discussion avoids terrorism-related aspects of these infections, because they were very well covered in the October 2005 issue of the Critical Care Clinics.

Safety and efficacy of lamivudine in patients with severe acute or fulminant hepatitis B, a multicenter experience

Acute hepatitis B progresses to liver failure with the need of liver transplantation in about 1% of cases. We treated patients with severe acute or fulminant hepatitis B with lamivudine in an attempt to prevent hepatitis B virus (HBV) reinfection after potential liver transplantation. Since September 2000, 17 patients with severe acute or fulminant HBV infection were treated with 100 or 150 mg lamivudine daily once we had evidence for a severe course as indicated by an INR >2.0. These were compared to a historic control from our unit and to external patients. Fourteen of the 17 patients (82.4%) survived with full recovery without liver transplantation. All these 14 individuals cleared HBsAg on lamivudine within less than 6 months. Twelve patients recovered quickly as indicated by a normalized prothrombin time within 1 week while two patients had a more prolonged course. None of the patients showed an adverse event. Three patients requiring transplantation despite lamivudine therapy had more advanced disease on admission, of whom one had additionally ingested paracetamol (acetaminophen) while the second was already HBV-DNA negative by polymerase chain reaction on admission. The lamivudine treated patients had significant higher frequency of survival without liver transplantation 82.4 vs 20% (4/20) in the historic control (P < 0.001). Similar data were derived from external centres using lamivudine (15/20, 75%). Lamivudine is safe in patients with severe acute or fulminant hepatitis B, leading to fast recovery with the potential to prevent liver failure and liver transplantation when administered early enough.

Extended liver resection and hepatic ischemia in pigs: a new, potentially reversible model to induce acute liver failure and study artificial liver support systems

BACKGROUND

Extended hepatectomy is a valid model for the study of acute liver failure. Since the porcine liver is comparable in size, morphology and anatomy to the human liver, we describe a technique employing hepatic ischemia and extended liver resection to induce acute liver failure in a porcine model as a means of studying bioartificial liver support.

METHOD

A subtotal (75-80% resection) extended left hepatectomy was performed in 7 pigs after 60 min warm ischemia of the future remnant liver. After resection, the animals were given the best supportive care and observed until death.

RESULTS

All animals died within 18-48 h, none as a result of surgical complications. Gross appearance of the liver showed severe steatosis of the right lateral lobe, and histology revealed severe coagulative necrosis of the whole lobule.

CONCLUSION

This technique of extended liver resection after hepatic ischemia in the porcine model may be useful for studies of potentially reversible acute liver failure and experimental bioartificial support.

Adult T-cell leukemia presenting with acute liver failure

Malignant infiltration of the liver is a rare cause of acute liver failure accounting for less than 1% of cases. We describe a case of adult T-cell leukemia (ATL) that presented with a prodromal illness that progressed to jaundice, hepatic encephalopathy, multisystem failure and death within 8 weeks. Liver histology revealed massive infiltration with atypical lymphocytes typical of ATL and liver necrosis.

Present and Future Developments in Hepatic Tissue Engineering for Liver Support Systems : State of the art and future developments of hepatic cell culture techniques for the use in liver support systems

The liver is the most important organ for the biotransformation of xenobiotics, and the failure to treat acute or acute-on-chronic liver failure causes high mortality rates in affected patients. Due to the lack of donor livers and the limited possibility of the clinical management there has been growing interest in the development of extracorporeal liver support systems as a bridge to liver transplantation or to support recovery during hepatic failure. Earlier attempts to provide liver support comprised non-biological therapies based on the use of conventional detoxification procedures, such as filtration and dialysis. These techniques, however, failed to meet the expected efficacy in terms of the overall survival rate due to the inadequate support of several essential liver-specific functions. For this reason, several bioartificial liver support systems using isolated viable hepatocytes have been constructed to improve the outcome of treatment for patients with fulminant liver failure by delivering essential hepatic functions. However, controlled trials (phase I/II) with these systems have shown no significant survival benefits despite the systems' contribution to improvements in clinical and biochemical parameters. For the development of improved liver support systems, critical issues, such as the cell source and culture conditions for the long-term maintenance of liver-specific functions in vitro, are reviewed in this article. We also discuss aspects concerning the performance, biotolerance and logistics of the selected bioartificial liver support systems that have been or are currently being preclinically and clinically evaluated.

The effect of acutely induced hepatic failure on remifentanil and fentanyl blood levels in a pig model

BACKGROUND AND OBJECTIVE

Opioids and especially fentanyl are widely used during the intensive care unit management of intracranial pressure in fulminant hepatic failure patients as well as during and after liver transplantation. The newer synthetic opioid remifentanil is also increasingly being used in critical care patients. Due to a lack of data relating to the influence of acute hepatic failure on remifentanil and fentanyl pharmacokinetics, this study was designed in order to determine the impact of this condition on the blood levels of these opioids using a pig model.

METHODS

Twenty pigs were randomly assigned to one of two groups: A group with surgically induced acute hepatic failure by hepatic devascularization (acute hepatic failure, n=10) and a control group (SHAM, n=10), subjected to a SHAM operation. Postoperatively, five animals in each group were administered remifentanil (1 microg kg-1 min-1) or fentanyl (0.2 microg kg-1 min-1) by continuous intravenous infusion. Blood samples for determination of drug concentrations were withdrawn at 0 h and 0.5, 1, 5, 7, 9 h after initiation of dosing.

RESULTS

Significantly higher blood concentrations were found in animals with acute hepatic failure compared to SHAM-operated animals receiving remifentanil at 5 h (P=0.003), 7 h (P=0.007) and 9 h (P=0.004) and fentanyl at 7 h (P<0.0005) and 9 h (P=0.05). The small number and the great variability in drug concentrations did not allow a detailed kinetic analysis to be performed. Approximate clearance values were found to be greater for the SHAM compared with the acute hepatic failure animals for both fentanyl and remifentanil.

CONCLUSIONS

Hepatic devascularization in our porcine acute hepatic failure model, appears to have significantly altered the disposition of fentanyl and unexpectedly remifentanil. These changes were thought to be brought about by severe disruption of blood flow and biotransformation in the liver, as well as by haemodynamic changes in the acute hepatic failure animals.

Protective effect of bicyclol on acute hepatic failure induced by lipopolysaccharide and D-galactosamine in mice

Bicyclol, a new anti-hepatitis drug, has been found to protect against liver injury induced by certain hepatotoxins. The present study was to investigate the effect of bicyclol on acute hepatic failure caused by an intraperitoneal injection of lipopolysaccharide (LPS, 15 microg/kg) and D-galactosamine (800 mg/kg) in mice. Bicyclol (150, 300 mg/kg) was given to mice orally once or three doses before the injection of LPS/D-galactosamine. The liver injury was assessed biochemically and histologically. The mortality in mice was monitored for 48 h after LPS/D-galactosamine poisoning. The expressions of cytokines, adhesion molecules and LPS receptors were determined. As a result, bicyclol showed significant protection as evidenced by the decrease of elevated aminotransferases and total bilirubin, reversion of prolonged prothrombin time and improvement of liver pathological injury in a dose-dependent manner. Pretreatment with bicyclol (300 mg/kg) also lowered the mortality after LPS/GalN intoxication. Furthermore, bicyclol inhibited the elevation of serum tumor necrosis factor-alpha, interferon-gamma and markedly enhanced interleukin-10. The expressions of intercellular adhesion molecule-1, lymphocyte function-associated antigen 1 and the transcription of CD14 and toll-like receptor 4 were also suppressed by bicyclol. These results suggest that bicyclol has remarkable hepatoprotective effects on LPS/D-galactosamine-induced liver injury and the possible mechanism is related to its anti-inflammatory action.

Boron ameliorates fulminant hepatic failure by counteracting the changes associated with the oxidative stress

Boron has well-defined biological effects and may be of therapeutic benefit. In the current paper, the effect of boron in the form of borax was tested in experimental animal model of fulminant hepatic failure (FHF). The syndrome was induced in female Wistar rats by three consecutive daily intraperitoneal injections of thioacetamide (400 mg/kg). In the treatment groups, rats received borax (4.0 mg/kg) orally for three consecutive days followed by thioacetamide. The group administered with thioacetamide plus vehicle, and the borax alone treated rats served as controls. In all groups, rats were terminated 4 h after administering the last dose of thioacetamide, and the tissue/serum was used to measure hepatic levels of thiobarbituric acid reactive substances, reduced glutathione, and various enzymes associated with oxidative stress including peroxide metabolizing enzymes and xanthine oxidase. In thioacetamide treated group, many fold increase in the activity level of serum marker enzymes suggesting FHF was observed that could be brought down significantly in rats receiving boron. Modulation and a correlation in the activity level of oxidant generating enzyme and lipid peroxidation as well as hepatic glutathione level was also observed in rats receiving thioacetamide. In the group receiving boron followed by thioacetamide, these changes could be minimized moderately. The activity level of the peroxide metabolizing enzymes and the tripeptide glutathione, which decreased following thioacetamide treatment were moderately elevated in the group receiving boron followed by thioacetamide. The data clearly shows that borax partly normalizes the liver and offsets the deleterious effects observed in FHF by modulating the oxidative stress parameters.

Resistance of collagenase-2 (matrix metalloproteinase-8)-deficient mice to TNF-induced lethal hepatitis

Acute fulminant liver failure is a serious worldwide health problem. Despite maximal supportive intensive care treatment, the disease offers a poor prognosis, with mortality rates of >80%. We have previously shown that a broad-spectrum inhibitor of matrix metalloproteinases (MMPs) confers complete protection in a mouse model of TNF-induced lethal hepatitis, thereby suggesting the possibility of protecting cancer patients against the deleterious side effects of TNF therapy. In our search for the individual matrix metalloproteinases involved, we found that the recently generated MMP-8-deficient mice are significantly protected against TNF-induced acute hepatitis. In contrast to their wild-type counterparts, MMP-8-null mice display very little hepatocyte necrosis and apoptosis, resulting in a much better survival outcome. We found that these animals clearly display impaired leukocyte influx into the liver and no release of the neutrophil-specific, LPS-induced CXC chemokine. Our findings provide evidence that MMP-8 plays an essential role in acute liver failure and might be a promising new target for the treatment for this illness.

Liver Transplantation for Fulminant Hepatic Failure Without Venovenous Bypass and Without Portacaval Shunting

Preservation of the caval vein during liver transplantation (OLT) has gained wide acceptance but portosystemic bypass or temporary portocaval shunt is still believed to be indicated in patients with fulminant hepatic failure. Herein we have described our initial experience with piggyback OLT without venovenous bypass and without portocaval shunting in five such patients. Division of the portal vein was always delayed until the native liver was completely dissected off the caval vein. The donor hepatic artery was anastomosed to the recipient aorta via an iliac interposition graft placed in the supraceliac position in two and at an infrarenal site in three patients. The ahepatic phase urinary output was low in the two patients in whom we applied supraceliac cross-clamping of the aorta. The mean ahepatic phase was 53 (45 to 67) minutes in four recipients who remained hemodynamically stable throughout surgery and prolonged to 5 hours in one patient due to a complicated supraceliac aortic anastomosis. Its repair resulted in hemodynamic instability, multiorgan failure, and death at 4 days following OLT. Four (80%) patients are alive in good condition with normal liver function after a mean of 12 (5 to 25) months of follow-up. In summary, liver transplantation for fulminant hepatic failure may be safely performed without venovenous bypass and without temporary portocaval shunting if the ahepatic phase is minimized and portal flow to the liver maintained up to the moment of hepatic excision. Arterial anastomosis with the supraceliac aorta prolongs the ahepatic phase and may impair kidney function: therefore, it should be avoided in these patients.

Self-assembling peptide nanofiber as a novel culture system for isolated porcine hepatocytes

Freshly isolated porcine hepatocytes are a very attractive cell source in the cell-based therapies to treat liver failure because of unlimited availability. However, due to the loss of hepatocyte functions in vitro, there is a need to develop a functional culture system to keep the cells metabolically active. Here we compared the effect of a self-assembling peptide nanofiber (SAPNF) as an extracellular matrix (ECM) with collagen type I on hepatocyte metabolic and secretion activities following hepatocyte isolation. Isolated porcine hepatocytes were cultured in SAPNF and collagen type I. Morphological assessment at different time points was performed by using SEM and phase contrast microscope. Metabolic and secretion activities were comparatively performed in the groups, by means of ammonia, lidocaine, and diazepam as well as albumin. Hepatocytes cultured on SAPNF revealed a three-dimensional spheroidal formation, thus maintaining cell differentiation status during 2 weeks of culture. On the other hand, hepatocytes in collagen revealed a spread shape, and by day 14 no hepatocyte-like cells were observed, but cells with long shape were present, thus revealing a degree of dedifferentiation in collagen culture. Hepatocytes in SAPNF were capable of drug-metabolizing activities and albumin secretion in higher ratio than those cultured on collagen. The present work clearly demonstrates the usefulness of SAPNF for maintaining differentiated functions of porcine hepatocytes in culture.

Fulminant hepatic failure bridged to liver transplantation with a molecular adsorbent recirculating system: a single-center experience

We herein describe the clinical course of a consecutive series of fulminant hepatic failure patients treated with a molecular adsorbent recirculating system (MARS), a cell-free albumin dialysis technique. From November 2000 to September 2002, seven adult patients ages 22-61 (median, 41), one male (14.2%) and six females (85.7%), affected by fulminant hepatic failure underwent seven courses (one to five sessions each, 6 hr in duration) of extracorporeal support using the MARS technique. Pre- and posttreatment blood glucose, liver function tests, ammonia, arterial lactate, electrolytes, hemodynamic parameters, arterial blood gases, liver histology, Glasgow Coma Scale, and coagulation studies were reviewed. No adverse side effects such as generalized bleeding on noncardiogenic pulmonary edema, often seen during MARS treatment, occurred in the patients included in this study. Six patients (85.7%) are currently alive and well, and one (14.2%) died. Four patients (57%) were successfully bridged (two patients in 1 day and two other patients in 4 days) to liver transplantation, while two (5%) recovered fully without transplantation. All the measured variables stabilized after commencement of the MARS. No differences were noted between the pre- and the post-MARS histology. We conclude that the MARS is a safe, temporary life support mechanism for patients awaiting liver transplantation or recovering from fulminant hepatic failure.

Differentiation of human embryonic stem cells to hepatocytes using deleted variant of HGF and poly-amino-urethane-coated nonwoven polytetrafluoroethylene fabric

Human embryonic stem (hES) cells have recently been studied as an attractive source for the development of a bioartificial liver (BAL). Here we evaluate the differentiation capacity of hES cells into hepatocytes. hES cells were subjected to suspension culture for 5 days, and then cultured onto poly-amino-urethane (PAU)-coated, nonwoven polytetrafluoroethylene (PTFE) fabric in the presence of fibroblast growth factor-2 (bFGF) (100 ng/ml) for 3 days, then with deleted variant of hepatocyte growth factor (dHGF) (100 ng/ml) and 1% dimethyl sulfoxide (DMSO) for 8 days, and finally with dexamethasone (10(-7) M) for 3 days. The hES cells showed gene expression of albumin in a time-dependent manner of the hepatic differentiation process. The resultant hES-derived hepatocytes metabolized the loaded ammonia and lidocaine at 7.8% and 23.6%, respectively. A million of such hepatocytes produced albumin and urea at 351.2 ng and urea at 7.0 microg. Scanning electron microscopy showed good attachment of the cells on the surface of the PTFE fabric and well-developed glycogen rosettes and Gap junction. In the present work we have demonstrated the efficient differentiation of hES cells to functional hepatocytes. The findings are useful to develop a BAL.

Functional activity of human hepatoma cells transfected with adenovirus-mediated hepatocyte nuclear factor (HNF)-4 gene

Fulminant hepatic failure (FHF) is still associated with high mortality despite recent advances in medical management. There is need of an effective and safe bioartificial liver (BAL) support to help keep patients with FHF alive until an organ becomes available for transplantation or the native liver recovers. The aim of this study was to establish highly functional liver cells by means of transfecting hepatocyte nuclear factor (HNF)-4 gene for the development of BAL. We constructed adenovirus vector carrying rat HNF-4 cDNA, and transfected to hepatoma-derived cell lines, HepG2 and HuH-7, to enforce expression of the exogenous HNF-4 gene. We analyzed expression of HNF-4, HNF-1, and liver-specific genes in cells infected by the adenovirus vector expressing HNF-4. Adenovirus-mediated HNF-4 gene transfer resulted in increases in expressions of HNF-4, HNF-1, and liver-specific genes such as apolipoproteins, alpha1-antitrypsin (alpha1-AT), phosphoenolpyruvate carboxy-kinase, cytochrome P450 families, and glutamine synthetase in transfected hepatoma cells. Cells overexpressing HNF-4 removed ammonia from medium supplemented with NH4Cl to a greater extent than control cells. These findings demonstrated that transfected cell lines restored differentiated gene expressions and liver-specific function by the overproduction of HNF-4. HNF-4-overexpressing hepatocyte cell lines are useful for bioreactor of BAL systems.

Short hairpin RNA modulates transforming growth factor beta signaling in life-threatening liver failure in mice

BACKGROUND & AIMS

Transforming growth factor beta (TGF-beta) receptor II (TGF-betaRII), which is essential for TGF-beta signaling and is involved in the causation or participates in the pathway of various human disorders, is consequently considered a key target for therapeutics and analysis of the pathophysiology associated with disruption of the TGF-beta system. In the liver, TGF-beta plays an essential role in hepatocyte apoptosis, growth inhibition, and progression of fibrogenesis. There is a critical need to introduce technology involving the TGF-beta system, such as RNA interference (RNAi), which has high potential for in vivo therapeutics and analytical activities.

METHODS

Here, we investigated the effect of short hairpin RNA targeting TGF-betaRII, using hepatocyte injury in human and mouse cell lines and liver injury mouse models.

RESULTS

We demonstrated that short hairpin RNA targeting TGF-betaRII can be used to silence TGF-betaRII genes in mouse and human cell lines, and physiologic and morphologic changes in hepatocytes suffering from acute injury are spared by RNAi-mediated gene silencing of the target gene and by suppressing downstream signal transduction. Furthermore, short hairpin RNA targeting TGF-betaRII protected mice from life-threatening acute liver failure.

CONCLUSIONS

Our study suggests the potential use of TGF-betaRII silencing by RNAi as an analytical tool for TGF-beta signaling and gene-specific therapy in human disorders.

A mathematical model to estimate global hepatitis B disease burden and vaccination impact

BACKGROUND

Limited data are available regarding global hepatitis B virus (HBV)-related morbidity and mortality and potential reduction in disease burden from hepatitis B vaccination.

METHODS

A model was developed to calculate the age-specific risk of acquiring HBV infection, acute hepatitis B (illness and death), and progression to chronic HBV infection. HBV-related deaths among chronically infected persons were determined from HBV-related cirrhosis and hepatocellular carcinoma (HCC) mortality curves, adjusted for background mortality. The effect of hepatitis B vaccination was calculated from vaccine efficacy and vaccination series coverage, with and without administration of the first dose of vaccine within 24 h of birth (i.e. birth dose) to prevent perinatal HBV infection.

RESULTS

For the year 2000, the model estimated 620,000 persons died worldwide from HBV-related causes: 580,000 (94%) from chronic infection-related cirrhosis and HCC and 40,000 (6%) from acute hepatitis B. In the surviving birth cohort for the year 2000, the model estimated that without vaccination, 64.8 million would become HBV-infected and 1.4 million would die from HBV-related disease. Infections acquired during the perinatal period, in early childhood (<5 years old), and > or = 5 years of age accounted for 21, 48, and 31% of deaths, respectively. Routine infant hepatitis B vaccination, with 90% coverage and the first dose administered at birth would prevent 84% of global HBV-related deaths.

CONCLUSION

Globally, most HBV-related deaths result from the chronic sequelae of infection acquired in the perinatal and early childhood periods. Inclusion of hepatitis B vaccine into national infant immunization programs could prevent >80% of HBV-related deaths.

New prognostic scoring model for liver transplantation in patients with non-acetaminophen-related fulminant hepatic failure

BACKGROUND

Many patients with fulminant hepatic failure die before receiving liver transplantation because of the difficulty of pinpointing the suitable timing for liver transplantation. The revised King's College criteria are useful for patients with acetaminophen-related fulminant hepatic failure; however, in those with non-acetaminophen-related fulminant hepatic failure, a new prognostic system that can accurately identify the suitable timing for liver transplantation is required.

METHODS

Using the first sample consisted of eighty patients with fulminant hepatic failure, we examined 2-week poor prognostic parameters at the time of diagnosis of fulminant hepatic failure (day 1) and on days 4, 8, and 15, respectively, and a 2-week prognostic scoring model was constructed. To confirm the accuracy of this model, validation was performed in the second sample consisting of 26 patients.

RESULTS

Cause of fulminant hepatic failure (hepatitis B virus or indeterminate), hepatic coma grade (III or IV), systemic inflammatory response syndrome (yes) and ratio of total to direct bilirubin (> 2.0) were associated with 2-week outcomes during days 1-15. Each of these four parameters was valued at +1. The 2-week survival rate in patients scoring <3 was > or = 80% in contrast to less than 30% in patients scoring > or = 3. When this scoring model was applied to the second sample, the sensitivity, specificity, and positive and negative predictive values were 87.5%, 90.0%, 93.3%, and 81.8%, respectively.

CONCLUSIONS

This scoring model may be useful for predicting 2-week outcomes and determining the suitable timing for liver transplantation in patients with non-acetaminophen-related fulminant hepatic failure.

Hepatic tumorigenesis in acute hepatic failure

We report on a 59-year-old woman and a 31-year-old man with no previous medical history of liver disease presenting with acute liver failure probably caused by drug toxicity. High urgency liver transplantation was performed 30 and 51 days after the onset of symptoms, respectively. Histomorphological evaluation of the explanted livers revealed incidental dysplastic nodules and hepatocellular carcinoma of up to 8 mm in diameter. Up to now only a few cases of metastatic liver disease and even fewer cases of primary liver cancer presenting as acute liver failure have been described. Our cases indicate hepatic tumorigenesis not as a cause of hepatic failure but either as an event taking place in parallel or as a process being induced by progressive liver failure.

Acute liver failure: from bench to bedside

Acute liver failure constitutes a challenge to clinicians and scientists alike. The course of the disease, usually unpredictable and polarizing, is associated with a high mortality unless liver transplantation is feasible, but can end in a spontaneous restitution. It poses many scientific questions regarding the mechanisms of liver cell damage and regeneration and the possibility of new therapeutic approaches. However, the performance of clinical studies in patients in acute liver failure presents problems because of the varied etiology, the small number of cases, and furthermore due to ethical and logistical difficulties. For this reason experimental investigations have gained a special importance. Arising from the improved understanding of the mechanisms of liver cell damage in acute liver failure, which may be primarily due not to the initial noxious agent alone but may also be triggered secondarily by the release of proinflammatory mediators, there are numerous options for liver cell protection, some of which have already proved successful in experimental studies. New insights into the mechanisms of regulation of liver regeneration and the physiological liver mass, gathered in particular from experimental models of partial hepatectomy and by the use of gene-manipulated animals, have contributed to the development of new therapeutic approaches for the stimulation of liver cell regeneration. Temporary liver support systems have already been successfully employed in some cases under clinical conditions. Although the systematic experimental investigation of many of the questions of acute liver failure has significantly contributed to a better understanding of liver cell damage and regeneration, the application of this new knowledge to clinical practice is to some extent made difficult by the artificial simplification that experimental studies inevitably entail and needs to be validated by controlled clinical studies.

Comparison of potentially hepatotoxic drugs among major US drug compendia

BACKGROUND

Although a large number of drugs include warnings or listed adverse reactions that describe reports of associated hepatotoxicity, the hepatotoxic risk is documented with different definitions in major drug compendia.

OBJECTIVES

The purposes of this study were to compare inclusion of potentially hepatotoxic drugs, and analyze the ratings of hepatotoxic risk among major drug compendia.

METHODS

To assess the risk of drug-associated hepatotoxicity, we used current literature of epidemiological studies and developed a 4-level rating scale of hepatotoxic drugs: 3, clear literature evidence of life-threatening hepatotoxicity; 2, multiple case reports or significant liver injuries; 1, no significant liver damage has been reported; and 0, no information. All drugs were evaluated using the 5 major US drug compendia: American Hospital Formulary Service (AHFS), United States Pharmacopeia Drug Information (USPDI), Facts and Comparisons (F&C), Physicians' Desk Reference (PDR), and Clinical Pharmacology (CP). Average rating scores were calculated as the sum of each drug rating score divided by the total number of drugs. One-way analysis of variance and independent t tests were conducted to compare the difference among the rating scores.

RESULTS

In total, 175 different drugs and 3 therapeutic classes with hepatotoxic effects were identified in the compendia, including 59 antineoplastics, 28 anti-infectives, 17 nonsteroidal anti-inflammatory drugs, 17 antipsychotics or phenothiazine derivatives, 9 angiotensin-converting enzyme inhibitors, 6 anticonvulsants, 4 histamine-2 receptor antagonists, and other drugs. Average rating scores were 1.65 for AHFS, 1.10 for USPDI, 1.27 for F&C, 1.34 for PDR, and 1.61 for CP (F=7.93, P<.0001). The risk categories were significantly different among compendia in 4 therapeutic classes of antipsychotics and/or phenothiazines (F=3.471, P=.011), nonsteroidal anti-inflammatory drugs (F=7.866, P<.0001), antineoplastics (F=2.476, P=.044), anti-infectives (F=2.003, P=.098), and angiotensin-converting enzyme inhibitors (F=38.125, P<.0001).

CONCLUSIONS

Rating scores of hepatotoxicity were significantly different among drug compendia. The different compendium put different emphasis on hepatotoxicity severity. Comprehensive evaluations of hepatotoxic-related drugs provide critical information for health practitioners.

Mathematical Model of Binding of Albumin—Bilirubin Complex to the Surface of Carbon Pyropolymer

We proposed a mathematical model and estimated the parameters of adsorption of albumin-bilirubin complex to the surface of carbon pyropolymer. Design data corresponded to the results of experimental studies. Our findings indicate that modeling of this process should take into account fractal properties of the surface of carbon pyropolymer.

Resolution of hypophosphatemia is associated with recovery of hepatic function in children with fulminant hepatic failure

Fulminant hepatic failure (FHF) is a rare but often fatal disease in children. Clinical and laboratory predictors of liver regeneration and recovery, however, have not been well established. We hypothesized that hypophosphatemia may indicate recovery of liver synthetic function in children with FHF. We retrospectively reviewed the medical records of children with FHF who were admitted to UCLA and recovered hepatic function either spontaneously or by liver transplantation (LTx). Serum phosphate (Ph) and prothrombin time or international normalized ratio (INR) were compared over the patient's clinical course. Records of 39 children who spontaneously recovered experienced profound hypophosphatemia that resolved as liver synthetic function improved. Similar patterns were seen in the 84 children who recovered after LTx. We found that hypophosphatemia precedes the recovery of liver synthetic function in children with FHF who recovered with or without transplantation, and that Ph levels return to normal as liver synthetic function improves. These data suggest that hypophosphatemia may be a useful laboratory indicator of recovering liver function in children with FHF.

Evolution of intrahepatic carbon, nitrogen, and energy metabolism in a D-galactosamine-induced rat liver failure model

A clearer picture of the hepatic metabolic pathways affected by fulminant hepatic failure (FHF) would help develop nutritional support and nonsurgical therapies for FHF. We characterized the evolution of hepatic metabolism in a rat model of FHF using an isolated perfused liver system together with a mass-balance model of intermediary metabolism. Principal component analysis (PCA) was used to identify potential new sensitive markers for FHF. To induce FHF, rats were given two D-galactosamine injections under fasting conditions. Controls were fasted only. Livers were harvested 1, 4, 8, and 12 h later and perfused with Eagle minimal essential medium supplemented with amino acids and bovine serum albumin, and equilibrated with 95% O2/5% CO2. At the 1 h time point, lactate release increased concomitant with a decrease in gluconeogenesis, TCA cycle and mitochondrial electron transport fluxes. At 4 h, amino acid metabolism and urea cycle fluxes were significantly depressed. By 8 h, gluconeogenesis had switched to glycolysis. By 12 h, amino acid metabolism was broadly inhibited, and there was a net release of many amino acids. Mass-balance analysis shows that the main source of ATP production in the FHF liver gradually changed from mitochondrial oxidative phosphorylation to glycolysis. PCA suggests that a linear combination of glucose, lactate, and glutamine concentrations in arterial plasma is a sensitive marker for FHF. We conclude that D-galactosamine causes early mitochondrial dysfunction while glycolytic ATP synthesis remains functional. Markers that are indirectly linked to these pathways may be used to evaluate the progression of FHF.

A20 protects mice from lethal radical hepatectomy by promoting hepatocyte proliferation via a p21waf1-dependent mechanism

The liver has a remarkable regenerative capacity, allowing recovery following injury. Regeneration after injury is contingent on maintenance of healthy residual liver mass, otherwise fulminant hepatic failure (FHF) may arise. Understanding the protective mechanisms safeguarding hepatocytes and promoting their proliferation is critical for devising therapeutic strategies for FHF. We demonstrate that A20 is part of the physiological response of hepatocytes to injury. In particular, A20 is significantly upregulated in the liver following partial hepatectomy. A20 protects hepatocytes from apoptosis and ongoing inflammation by inhibiting NF-kappaB. Hepatic expression of A20 in BALB/c mice dramatically improves survival following extended and radical lethal hepatectomy. A20 expression in the liver limits hepatocellular damage hence maintains bilirubin clearance and the liver synthetic function. In addition, A20 confers a proliferative advantage to hepatocytes via decreased expression of the cyclin-dependent kinase inhibitor p21(waf1). In conclusion, A20 provides a proliferative advantage to hepatocytes. By combining anti-inflammatory, antiapoptotic and pro-proliferative functions, A20-based therapies could be beneficial in prevention and treatment of FHF.

Catholic university experience with molecular adsorbent recycling system in patients with severe liver failure

BACKGROUND AND AIM

Molecular adsorbent recycling system (MARS) treatment is able to remove both hydrosoluble and small- and medium-sized lipophilic toxins. MARS plays an important role in modifying liver failure complications, such as hepatorenal syndrome and hepatic encephalopathy. We sought to evaluate the clinical efficacy and safety of a MARS device in a consecutive series of hepatic failure patients.

MATERIALS

Twenty patients with acute liver failure, transplantation failure, or acute on chronic liver failure fulfilled the inclusion criteria of total bilirubin > or =10 mg/dL and at least one of the following: hepatic encephalopathy (HE) > or =II grade, hepatorenal syndrome (HRS) for chronic patients or total bilirubin > or =5 mg/dL and HE > or =I grade for acute patients.

RESULTS

MARS was able to reduce cholestatic parameters and improve neurologic status and renal function parameters in all treated patients. We also observed an improvement in the 3-month survival rate compared to the expected outcome in patients with MELD scores between 20 and 29, as well as 30 and 39.

CONCLUSIONS

Based on these results, we confirm the safety and clinical efficacy of MARS treatment, with the best results in patients with MELD score of 20 to 29. Further studies are necessary to confirm whether this treatment is able to modify patient outcomes and prognosis.

Reversible encephalopathy secondary to paratyphoid infection and concomitant acute Hepatitis A

Reversible encephalopathy has been described in association with typhoid fever as well as nontyphoidal salmonella infections. A diagnostic dilemma as to the cause of encephalopathy may arise when there is coexistent acute viral hepatitis and suspicion of fulminant liver failure. The authors report a patient who presented with acute icteric hepatitis A infection and a concomitant febrile illness due to Salmonella paratyphi associated with progressive encephalopathy and coma. The young man developed high-grade fever and coma. Concomitant infection with S. paratyphi was diagnosed and the patient's encephalopathy resolved rapidly with antibiotic therapy. This is the first report of a putative association of S. paratyphi infection and reversible encephalopathy. Salmonella and hepatitis A virus infection are both transmitted via the fecal-oral route, and awareness of this association is important in the management of such patients.

An experimental animal model of fulminant hepatic failure in pigs

The objective of this study was to develop an experimental animal model of fulminant hepatic failure to test the efficacy of the bioartificial liver system. The portal vein and the hepatic artery were clamped intermittently and then the hepatic artery was ligated (ligation group, n=5). Pigs whose hepatic arteries were not ligated after clamping were assigned to the non-ligation group (n=5). The biochemical changes in blood, histologic alterations of the liver and neurologic examination for pigs were checked up. All animals died within 17 hr in the ligation group. On the other hand, all animals survived more than 7 days in the non-ligation group. In the ligation group, the levels of ammonia, lactic acid and creatinine showed a progressively increasing pattern. Prothrombin time was also prolonged gradually. Cytoplasmic condensation and nuclear pyknosis of hepatocytes were detected histologically at autopsy. Neurologic findings such as decreased pain sensation, tachypnea and no light reflex of pupils were observed. The findings shown in the ligation group are similar to the clinical features of fulminant hepatic failure in human and this animal model is reproducible. Therefore, this can be a suitable animal model to evaluate the efficacy of the bioartificial liver system for treating fulminant hepatic failure.

Stimulation of hepatocyte survival and suppression of CCl4-induced liver injury by the adenovirally introduced C/EBPbeta gene

Gene therapy has attracted attention as a potentially effective alternative to liver transplantation for the treatment of hepatic failure. We chose the C/EBPbeta gene, which plays vital roles in liver regeneration, as a candidate for gene therapy, and examined its effect on hepatocyte survival and the suppression of liver inflammation. C/EBPbeta gene overexpression significantly maintained hepatocyte viability during 12 days of the culture. Urea synthesis ability, which is a liver-specific function, in Adv-C/EBPbeta-infected hepatocytes was stably maintained during the culture, but the activity per cell was significantly lower than that in non-infected cells. On the contrary, DNA synthesis activity in Adv-C/EBPbeta-infected hepatocytes was significantly higher than that in non-infected cells. COX-2 was induced in Adv-C/EBPbeta-infected hepatocytes, and the addition of NS398, a specific inhibitor of COX-2, suppressed the viability-maintenance effect. COX-2 was thus shown to be involved in the survival effect of C/EBPbeta gene. The introduction of the C/EBPbeta gene into liver-damaged mice significantly suppressed the serum AST and ALT activities. These results indicate that C/EBPbeta appears to be a survival factor under stressful conditions, and the introduction of the gene has therapeutic function against liver injury.

The newly established human hepatocyte cell line: application for the bioartificial liver

BACKGROUND/AIMS

Human hepatocyte cell lines are reported to lose many of their biochemical functions in a hybrid artificial liver support system (HALSS). Differentiation therapy is useful to up-regulate liver function.

METHODS

The human hepatoblastoma cell line HepG2 was transfected with HSV/tk gene. Albumin synthesis and ammonia removal activity were evaluated when HepG2/tk was cultured with histone deacetylase inhibitor (FR228) and peroxisome proliferator activated receptor-gamma ligand (pioglitazone). To investigate the function of HepG2/tk in vivo, cell transplantation for 90% hepatectonized rats was conducted.

RESULTS

We established stable cell lines which expressed HSV/tk and were sensitive to gancyclovir in vitro and in vivo. Both albumin synthesis rate and ammonia removal rate improved for HepG2/tk incubated with FR228 and pioglitazone for 3 days, which induced nuclear transport of p21. Rats with intrasplenic injection of HepG2/tk precultured for 3 days with FR228 and pioglitazone survived significantly longer than the control rats. The ammonia and total bilirubin concentrations were significantly lower in the test group than in the control group. The injection of gancyclovir inhibited the prolonged survival of the rats with precultured HepG2/tk.

CONCLUSIONS

HepG2/tk is safe as well as enhancing high levels of liver function. It will be a potential cell source for HALLS in the future.

Hepatocyte organoid culture in elliptic hollow fibers to develop a hybrid artificial liver

A novel organoid culture was developed in which hepatocytes maintain high liver functions for more than several weeks in vitro. The main disadvantage of tissue-engineered organoids is the lack of a blood vessel structure between the aggregated cells. Because of depletion of oxygen, the thickness from the surface of an organoid at which hepatocytes can survive is limited. This study showed that a rat hepatocyte organoid that forms by using centrifugal force in a hollow fiber (HF) had a survival limit thickness of about 80 - 100 microm from the surface of the organoid. Based on the value, we designed an elliptic HF having less than 150 microm minor diameter by using a simple annealing method. All hepatocytes were supplied with oxygen and formed an organoid without a dead cell layer in this HF A hepatocyte organoid in an elliptic HF maintained ammonia removal activity twice as high as in the original HF for at least one month during culture. Albumin secretion activity of an organoid in an elliptic HF was also maintained for at least one month and was the same level as that of liver in a living body. In conclusion, organoid culture by using an elliptic HF seems to be a promising technique to develop a hybrid artificial liver.

Fulminant hepatic failure and the potential role of liver dialysis

Fulminant hepatic failure (FHF) carries a high mortality. We aimed to review the prognostic factors and explore the potential role of Liver Dialysis (LD). Fifty-two patients were reviewed. The etiologies were acetaminophen toxicity (33%), viral hepatitis (18%), autoimmune (10%), idiosyncratic drug reactions (8%), others (6%) and undetermined (25%). Patients with acetaminophen had a significantly higher survival compared to the non-acetaminophen group (p=0.04). Patients with grade 3 encephalopathy had a mortality of 68%, among 5 patients with grade IV encephalopathy, 2 survived and both had had treatment with LD. Chi-square with Fisher's exact test was used for statistical analysis. Our study confirmed that the diagnosis of non-acetaminophen induced FHF and reduced initial serum factor V level are associated with fatal outcome. Timely OLT significantly improved the survival. The role of LD in hepatic regeneration or as a bridge to OLT needs to be further studied with prospective control trials.

Clinical outcome and virological characteristics of hepatitis B-related acute liver failure in the United States

The role of hepatitis B virus (HBV) genotypes in the outcome of acute HBV infection is unclear. In this study, we aimed to evaluate the clinical and virological features of patients with hepatitis B-related acute liver failure (HBV-ALF) in the US. Clinical and laboratory features of consecutive patients with HBV-ALF from the US ALF Study Group were analysed. Prevalence of HBV genotypes, precore stop (G1896A) and core promoter dual (T1762A, A1764T) variants among patients with HBV-ALF were compared with a cohort of 530 patients with chronic HBV infection. Thirty-four HBV-ALF patients were studied: mean age 41 years, 56% men, 25 had detectable HBV-DNA. HBV genotypes A, B, C and D were found in 36, 24, 8 and 32% patients, respectively. Precore stop and core promoter dual variants were detected in 32 and 44% of patients, respectively. Twenty-three (68%) patients survived: 14 after liver transplant, nine without transplant. Older age was the only independent factor associated with poor outcome. Compared with patients with chronic HBV infection, patients with ALF were more likely to be non-Asians (88% vs 44%, P = 0.005) and to have genotype D (32% vs 10%, P < 0.01). A higher prevalence of HBV genotype D persisted even after matching for race and HBeAg status (32% vs 16%, P = 0.007). We concluded that HBV genotype D was more frequently found in patients with HBV-ALF than those with chronic HBV infection in the US. Further studies are needed to determine if HBV genotypes play a role in the outcome of acute HBV infection.

Liver transplantation in fulminant hepatic failure: experience with 40 adult patients over a 17-year period

INTRODUCTION

To evaluate the influence of pretransplantation recipient and donor prognostic factors on graft-patient survival.

MATERIALS AND METHODS

Between April 1986 and June 2003, 40 liver transplantation (LT) procedures to treat fulminant hepatic failure were performed (5.7%). Twenty-one pre-LT recipient and donor variables were retrospectively considered for analysis.

RESULTS

The indications for LT were hyperacute (62.5%), acute (35%), and subacute hepatic failure (2.5%). Glasgow Coma Scale scores ranged from <5 in 22 patients to > or =5 in 18 patients. The causes were hepatitis B (n = 21), unknown (n = 10), Amanita phalloides (n = 5), and other (n = 4). The 1-year graft and patient survival rates were 48.3% and 61.3%, respectively. Perioperative and late mortality was 27.5% and 22.5%. The only variable statistically significant for graft survival was waiting list time for LT <48 hours (P = .05).

DISCUSSION

Liver transplantation is the best treatment for fulminant hepatic failure, with a 1-year patient survival rate of 61.3%. The short waiting list time has an important role in outcome.