Acute liver failure

King's College Hospital Criteria for non-acetaminophen induced acute liver failure in an international cohort of children

OBJECTIVE

To validate King's College Hospital criteria (KCHC) in children with non-acetaminophen induced pediatric acute liver failure (PALF) and to determine whether re-optimizing the KCHC would improve predictive accuracy.

STUDY DESIGN

We used the PALF study group database. Primary outcomes were survival without liver transplantation vs death at 21 days following enrollment. Classification and regression tree analysis was used to determine if modification of KCHC parameters would improve classification of death vs survival.

RESULTS

Among 163 patients who met KCHC, 54 patients (33.1%) died within 21 days. Sensitivity of KCHC in this cohort was significantly lower than in the original study (61% vs 91%, P = .002), and specificity did not differ significantly. The positive predictive value (PPV) and negative predictive value (NPV) of KCHC for this cohort was 33% and 88% respectively. Classification and regression tree analysis yielded the following optimized parameters to predict death: grade 2-4 encephalopathy, international normalized ratio >4.02, and total bilirubin >2.02 mg/dL. These parameters did not improve PPV, but NPV was significantly better (88% vs 92%, P < .0001).

CONCLUSIONS

KCHC does not reliably predict death in PALF. With a PPV of 33%, twice as many participants who met KCHC recovered spontaneously than died, indicating that using KCHC may cause over utilization of liver transplantation. Re-optimized cutpoints for KCHC parameters improved NPV, but not PPV. Parameters beyond the KCHC should be evaluated to create a predictive model for PALF.

Brain edema in acute liver failure and chronic liver disease: similarities and differences

Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome that typically develops as a result of acute liver failure or chronic liver disease. Brain edema is a common feature associated with HE. In acute liver failure, brain edema contributes to an increase in intracranial pressure, which can fatally lead to brain stem herniation. In chronic liver disease, intracranial hypertension is rarely observed, even though brain edema may be present. This discrepancy in the development of intracranial hypertension in acute liver failure versus chronic liver disease suggests that brain edema plays a different role in relation to the onset of HE. Furthermore, the pathophysiological mechanisms involved in the development of brain edema in acute liver failure and chronic liver disease are dissimilar. This review explores the types of brain edema, the cells, and pathogenic factors involved in its development, while emphasizing the differences in acute liver failure versus chronic liver disease. The implications of brain edema developing as a neuropathological consequence of HE, or as a cause of HE, are also discussed.

Etiologies and outcomes of acute liver failure in a spanish community

Previous retrospective study (1992 to 2000) performed in Spain showed that drug toxicity, viral hepatitis, and indeterminate etiology were the most prevalent causes of acute liver failure (ALF). In the last decade, there is no information about ALF in our country. For these reasons we analyze retrospectively, in a ten-year period (2000 to 2010), the presumed causes, clinical characteristics, course, and outcome of ALF in a Spanish community. Causes of ALF were indeterminate in 4 patients (24%), acute hepatitis B infection in 4 patients (24%), drug or toxic reactions in 4 patients (24%), including one case of acetaminophen overdose, followed by miscellaneous causes. The overall short-term survival (6 weeks after admission) was 65%. Liver transplantation was performed in 11 patients with a survival of 82%. Despite fulfilling criteria, 2 patients were not transplanted because of contraindications; they both died. In summary, acute hepatitis B and indeterminate cause are still being the most frequent causes of ALF in our region, and patients with ALF have an excellent chance of survival after emergency liver transplantation. Acetaminophen overdose still represents a very rare cause of ALF in our community.

Incorporating dynamics for predicting poor outcome in acute liver failure patients

Acute liver failure (ALF), also known as fulminant hepatic failure (FHF), is a devastating clinical syndrome with a high mortality of 60%-90%. An early and exact assessment of the severity of ALF together with prediction of its further development is critical in order to determine the further management of the patient. A number of prognostic models have been used for outcome prediction in ALF patients but they are mostly based on the variables measured at one time point, mostly at admission. ALF patients rarely show a static state: rapid progress to a life threatening situation occurs in many patients. Since ALF is a dynamic process, admission values of prognostic variables change over time during the clinical course of the patient. Kumar et al developed a prognostic model [ALF early dynamic (ALFED)] based on early changes in values of variables which predicted outcome. ALFED is a model which seems to be worthwhile to test in ALF patients in other parts of the world with different aetiologies. Since the exact pathophysiology of ALF is not fully known and is certainly complex, we believe that adding promising variables involved in the pathophysiology of ALF to the dynamic approach might even further improve prognostic performance. We agree with Kumar et al that an improved dynamic prognostic model should be based on simplicity (easily to be performed at the bedside) and accuracy. Our comments presented in this paper may be considered as recommendations for future optimization of ALF prediction models.

Liver regeneration signature in hepatitis B virus (HBV)-associated acute liver failure identified by gene expression profiling

INTRODUCTION

The liver has inherent regenerative capacity via mitotic division of mature hepatocytes or, when the hepatic loss is massive or hepatocyte proliferation is impaired, through activation of hepatic stem/progenitor cells (HSPC). The dramatic clinical course of acute liver failure (ALF) has posed major limitations to investigating the molecular mechanisms of liver regeneration and the role of HSPC in this setting. We investigated the molecular mechanisms of liver regeneration in 4 patients who underwent liver transplantation for hepatitis B virus (HBV)-associated ALF.

METHODS AND FINDINGS

Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two clusters of ALF that segregated according to histopathological severity massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong HSPC gene signature, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of stem cell genes (EpCAM, CK19, CK7), whereas the most up-regulated genes in SHN were related to cellular growth and proliferation. The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound-healing process.

CONCLUSION

Our data provide evidence for a distinct gene signature in HBV-associated ALF whose intensity is directly correlated with the histopathological severity. HSPC activation and fibrogenesis positively correlated with the extent of liver necrosis. Moreover, we detected a tumorigenesis gene signature in ALF, emphasizing the close relationship between liver regeneration and liver cancer.

Liver regeneration signature in hepatitis B virus (HBV)-associated acute liver failure identified by gene expression profiling

Introduction

The liver has inherent regenerative capacity via mitotic division of mature hepatocytes or, when the hepatic loss is massive or hepatocyte proliferation is impaired, through activation of hepatic stem/progenitor cells (HSPC). The dramatic clinical course of acute liver failure (ALF) has posed major limitations to investigating the molecular mechanisms of liver regeneration and the role of HSPC in this setting. We investigated the molecular mechanisms of liver regeneration in 4 patients who underwent liver transplantation for hepatitis B virus (HBV)-associated ALF.

Methods and Findings

Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two clusters of ALF that segregated according to histopathological severity massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong HSPC gene signature, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of stem cell genes (EpCAM, CK19, CK7), whereas the most up-regulated genes in SHN were related to cellular growth and proliferation. The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound-healing process.

Conclusion

Our data provide evidence for a distinct gene signature in HBV-associated ALF whose intensity is directly correlated with the histopathological severity. HSPC activation and fibrogenesis positively correlated with the extent of liver necrosis. Moreover, we detected a tumorigenesis gene signature in ALF, emphasizing the close relationship between liver regeneration and liver cancer.

Specificity of an anti-capsid antibody associated with Hepatitis B Virus-related acute liver failure

Previously, the livers of patients suffering from acute liver failure (ALF), a potentially fatal syndrome arising from infection by Hepatitis B Virus (HBV), were found to contain massive amounts of an antibody specific for the core antigen (HBcAg) capsid. We have used cryo-electron microscopy and molecular modeling to define its epitope. HBV capsids are icosahedral shells with 25Å-long dimeric spikes, each a 4-helix bundle, protruding from the contiguous "floor". Of the anti-HBcAg antibodies previously characterized, most bind around the spike tip while one binds to the floor. The ALF-associated antibody binds tangentially to a novel site on the side of the spike. This epitope is conformational. The Fab binds with high affinity to its principal determinants but has lower affinities for quasi-equivalent variants. The highest occupancy site is on one side of a spike, with no detectable binding to the corresponding site on the other side. Binding of one Fab per dimer was also observed by analytical ultracentrifugation. The Fab did not bind to the e-antigen dimer, a non-assembling variant of capsid protein. These findings support the propositions that antibodies with particular specificities may correlate with different clinical expressions of HBV infection and that antibodies directed to particular HBcAg epitopes may be involved in ALF pathogenesis.

Review: Artificial liver support systems

Despite recent advances in medical therapy, patients with fulminant hepatic failure (FHF) have a mortality rate approaching 90%. Many patients die because of failure to arrest the progression of cerebral edema. Liver transplantation has improved survival to 65% to 75%. However, there is a shortage of donors and approximately one half of the patients with FHF will die while awaiting liver transplantation. There is thus a need to develop an extracorporeal liver assist system to help keep these patients alive and neurologically intact until either an organ becomes available for transplantation or the native liver recovers from injury. Such a system could also be used during the period of functional recovery from massive liver resection or to assist patients with decompensated chronic liver disease. Over the years, various methods utilizing charcoal and resin hemoperfusion, dialysis, plasma exchange, and other methods of blood detoxification have been developed and tested, but none have gained wide acceptance. This was due to: (i) incomplete understanding of the pathophysiology of liver failure; (ii) lack of accurate methods of assessment, quantitation, and stratification of the degree of liver dysfunction; and (iii) inadequate numbers of prospective controlled clinical trials examining the effects of specific therapeutic modalities. Liver support systems utilizing liver tissue preparations were developed in the 1950s, but it was not until recently that advances in hepatocyte isolation and culture, better understanding of hepatocyte-matrix interactions, and improved hollow-fiber technology have resulted in the development of a new generation of liver assist devices. Some of these devices are currently being tested in the clinical setting. In a preliminary clinical study, we have used a porcine hepatocyte-based liver support system to treat patients with acute liver failure as well as patients with acute exacerbation of chronic liver disease. Patients in the first group, who were candidates for transplantation, were successfully bridged to a transplant with excellent survival. No obvious benefit from bioartifical liver treatments was seen in the second group. It is possible that, in this group, patients will have to be treated earlier and for longer periods of time. Prospective controlled trials will be initiated as soon as the current phase I study is concluded to determine the efficacy of this system in both patients populations. (c) 1996 John Wiley & Sons, Inc.

Systematic review: extracorporeal bio-artificial liver-support system for liver failure

BACKGROUND

Orthotopic liver transplantation (OLT) is the only effective long-term treatment for liver failure by now. However, it is not yet a perfect choice due to donor-organ shortage and the need of a lifelong immunosuppressive therapy. Therefore, it is necessary to find a new approach to fighting the disease. Several published clinical trials have reported the therapeutic effect of bio-artificial liver (BAL) for liver failure.

OBJECTIVE

To overview and evaluate the current clinical application and outcomes of extracorporeal BAL support system during the past 15 years.

METHODS

Relevant studies were retrieved from PubMed and Cochrane Library databases. Independent assessments and the final consensus decision were performed by three independent reviewers. Acceptable study designs included randomized controlled trials, controlled clinical trials, and case reports. A total of 31 studies were tabulated and critically appraised in terms of characteristics, methods, and outcomes.

RESULTS

There was a trend of falling into the normal ranges with the clinical and biochemical parameters after the BAL treatment. The neurological status of most patients was improved or stabilized during BAL treatment as well. No significant effect on survival could be seen after the BAL treatment.

CONCLUSIONS

Although BAL system proved to be a success in some clinical cases reported, it still needs to be improved greatly.

Inhibition of glycogen synthase kinase 3β ameliorates D-GalN/LPS-induced liver injury by reducing endoplasmic reticulum stress-triggered apoptosis

BACKGROUND

Glycogen synthase kinase 3β(GSK3β) is a ubiquitous serine-threonine protein kinase that participates in numerous cellular processes and disease pathophysiology. We aimed to determine therapeutic potential of GSK3β inhibition and its mechanism in a well-characterized model of lipopolysaccharide (LPS)-induced model of acute liver failure (ALF).

METHODOLOGY

In a murine ALF model induced by D-GalN(700 mg/kg)/LPS(10 µg/kg), we analyzed GSK3β mechanisms using a specific chemical inhibitor, SB216763, and detected the role of endoplasmic reticulum stress (ERS). Mice were administered SB216763 at 2 h before or after D-GalN/LPS injection, respectively, and then sacrificed 6 h after D-GalN/LPS treatment to evaluate its prophylactic and therapeutic function. The lethality rate, liver damage, ERS, cytokine expression, MAP kinase, hepatocyte apoptosis and expression of TLR 4 were evaluated, respectively. Whether the inhibition of GSK3β activation protected hepatocyte from ERS-induced apoptosis was investigated in vitro.

PRINCIPAL FINDINGS

GSK3β became quickly activated (dephosphorylated) upon D-GalN/LPS exposure. Administration of SB216763 not only ameliorated liver injury, as evidenced by reduced transaminase levels, and well-preserved liver architecture, but also decreased lethality. Moreover, GSK3β inhibition resulted in down-regulation of pro-apoptotic proteins C/EBP-homologous protein(CHOP) and caspase-12, which are related to ERS. To further demonstrate the role of ERS, we found that GSK3β inhibition protected hepatocyte from ERS-induced cell death. GSK3β inhibition down-regulated the MAPK pathways, reduced expression of inflammatory cytokines and decreased expression of TLR4.

CONCLUSIONS

Our findings demonstrate the key function of GSK3β signaling in the pathophysiology of ALF, especially in regulating the ERS, and provide a rationale for targeting GSK3β as a potential therapeutic strategy to ameliorate ALF.

Liver transplantation in adults: Choosing the appropriate timing

Liver transplantation is indicated in patients with acute liver failure, decompensated cirrhosis, hepatocellular carcinoma and rare liver-based genetic defects that trigger damage of other organs. Early referral to a transplant center is crucial in acute liver failure due to the high mortality with medical therapy and its unpredictable evolution. Referral to a transplant center should be considered when at least one complication of cirrhosis occurs during its natural history. However, because of the shortage of organ donors and the short-term mortality after liver transplantation on one hand and the possibility of managing the complications of cirrhosis with other treatments on the other, patients are carefully selected by the transplant center to ensure that transplantation is indicated and that there are no medical, surgical and psychological contraindications. Patients approved for transplantation are placed on the transplant waiting list and prioritized according to disease severity. Thus, the appropriate timing of transplantation depends on recipient disease severity and, although this is still a matter of debate, also on donor quality. These two variables are known to determine the “transplant benefit” (i.e., when the expected patient survival is better with, than without, transplantation) and should guide donor allocation.

Acute liver failure in Japan: definition, classification, and prediction of the outcome

Acute liver failure is a clinical syndrome characterized by hepatic encephalopathy and a bleeding tendency due to severe impairment of liver function caused by massive or submassive liver necrosis. Viral hepatitis is the most important and frequent cause of acute liver failure in Japan. The diagnostic criteria for fulminant hepatitis, including that caused by viral infections, autoimmune hepatitis, and drug allergy induced-liver damage, were first established in 1981. Considering the discrepancies between the definition of fulminant hepatitis in Japan and the definitions of acute liver failure in the United States and Europe, the Intractable Hepato-Biliary Disease Study Group established the diagnostic criteria for "acute liver failure" for Japan in 2011, and performed a nationwide survey of patients seen in 2010 to clarify the demographic and clinical features and outcomes of these patients. According to the survey, the survival rates of patients receiving medical treatment alone were low, especially in those with hepatic encephalopathy, despite artificial liver support, consisting of plasma exchange and hemodiafiltration, being provided to almost all patients in Japan. Thus, liver transplantation is inevitable to rescue most patients with hepatic encephalopathy. The indications for liver transplantation had, until recently, been determined according to the guideline published by the Acute Liver Failure Study Group in 1996. Recently, however, the Intractable Hepato-Biliary Disease Study Group established a scoring system to predict the outcomes of acute liver failure patients. Algorithms for outcome prediction have also been developed based on data-mining analyses. These novel guidelines need further evaluation to determine their usefulness.

Omega-3 polyunsaturated fatty acids promote liver regeneration after 90% hepatectomy in rats

AIM: To evaluate the effectiveness of omega-3 polyunsaturated fatty acid (ω-3 PUFA) administration on liver regeneration after 90% partial hepatectomy (PH) in rats.

METHODS: ω-3 PUFAs were intravenously injected in the ω-3 PUFA group before PH surgery. PH, sparing only the caudate lobe, was performed in both the control and the ω-3 PUFA group. Survival rates, liver weight/body weight ratios, liver weights, HE staining, transmission electron microscope imaging, nuclear-associated antigen Ki-67, enzyme-linked immunosorbent assay and signal transduction were evaluated to analyze liver regeneration.

RESULTS: All rats in the control group died within 30 h after hepatectomy. Survival rates in the ω-3 PUFA group were 20/20 at 30 h and 4/20 1 wk after PH. Liver weight/body weight ratios and liver weights increased significantly in the ω-3 PUFA group. The structure of sinusoidal endothelial cells and space of Disse was greatly restored in the ω-3 PUFA group compared to the control group after PH. In the ω-3 PUFA group, interleukin (IL)-4 and IL-10 levels were significantly increased whereas IL-6 and tumor necrosis factor-α levels were dramatically decreased. In addition, activation of protein kinase B (Akt) and of signal transducer and activator of transcription 3 signaling pathway were identified at an earlier time after PH in the ω-3 PUFA group.

CONCLUSION: Omega-3 polyunsaturated fatty acids may prevent acute liver failure and promote liver regeneration after 90% hepatectomy in rats.

Toxic hepatitis in occupational exposure to solvents

The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.

Angiopoietin-2 in acute liver failure

OBJECTIVE

Angiopoietin-2, an antagonistic ligand of the endothelial Tie2 receptor, has been identified as a gatekeeper of endothelial activation. We examined whether the release of Angiopoietin-2 correlates with surrogates of organ dysfunction and outcome in patients with acute liver failure.

DESIGN

Retrospective clinical and immunohistological study.

SETTING

Intensive care unit of a university hospital.

PATIENTS

Thirty-seven patients with acute liver failure and 20 healthy control subjects.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Angiopoietin-2 levels were measured in sera from 37 patients with acute liver failure on admission and from 20 healthy control subjects. Median age of patients with acute liver failure was 34 yrs, 29 were female, and 21 developed encephalopathy grade 3 or greater. Nine patients survived to day 28 without transplantation, five died without transplantation, and 23 received a transplant. Median (interquartile range) Angiopoietin-2 serum concentrations steadily increased across the following groups: healthy control subjects (1.4 [0.9-1.7] ng/mL), patients with transplant-free recovery (10.0 [4.7-12.1] ng/mL), and patients who reached the composite end point of death or emergency liver transplantation (16.8 [11.3-39.5] ng/mL). Angiopoietin-2 release correlated strongly with surrogate markers of organ dysfunction and disease severity measures (lactate, platelet count, Sequential Organ Failure Assessment score, and Simplified Acute Physiology Score III). Angiopoietin-2 levels were higher in patients with acute kidney injury and patients on mechanical ventilation. Furthermore, Angiopoietin-2 levels were closely associated with Bilirubin-Lactate-Etiology score but not with other liver-specific markers. Unadjusted and adjusted Cox's proportional hazards analyses identified Angiopoietin-2 as a predictor of the composite end point of death or transplantation. Finally, immunohistological studies showed that Angiopoietin-2 protein was upregulated in acute liver failure explants compared with matched liver biopsies obtained at baseline.

CONCLUSIONS

Collectively, our data show that circulating Angiopoietin-2, which potentially originates from the injured liver, correlates with several features of multiple organ dysfunction syndrome and independently predicts outcome. Tie2 agonists may have potential as an endothelium-targeted therapy to ameliorate multiple organ dysfunction syndrome and improve outcome in acute liver failure.

Fully biodegradable and cationic poly(amino oxalate) particles for the treatment of acetaminophen-induced acute liver failure

Acute inflammatory diseases are one of major causes of death in the world and there is great need for developing drug delivery systems that can target drugs to macrophages and enhance their therapeutic efficacy. Poly(amino oxalate) (PAOX) is a new family of fully biodegradable polymer that possesses tertiary amine groups in its backbone and has rapid hydrolytic degradation. In this study, we developed PAOX particles as drug delivery systems for treating acute liver failure (ALF) by taking the advantages of the natural propensity of particulate drug delivery systems to localize to the mononuclear phagocyte system, particularly to liver macrophages. PAOX particles showed a fast drug release kinetics and excellent biocompatibility in vitro and in vivo. A majority of PAOX particles were accumulated in liver, providing a rational strategy for effective treatment of ALF. A mouse model of acetaminophen (APAP)-induced ALF was used to evaluate the potential of PAOX particles using pentoxifylline (PTX) as a model drug. Treatment of PTX-loaded PAOX particles significantly reduced the activity of alanine transaminase (ALT) and inhibited hepatic cell damages in APAP-intoxicated mice. The high therapeutic efficacy of PTX-loaded PAOX particles for ALF treatment may be attributed to the unique properties of PAOX particles, which can target passively liver, stimulate cellular uptake and trigger a colloid osmotic disruption of the phagosome to release encapsulated PTX into the cytosol. Taken together, we believe that PAOX particles are a promising drug delivery candidate for the treatment of acute inflammatory diseases.

Etiologies and outcomes of acute liver failure in Germany

BACKGROUND & AIMS

Acute liver failure (ALF) is a severe form of acute liver injury that can progress to multiple organ failure. We investigated causes and outcomes of ALF.

METHODS

Eleven university medical centers in Germany were asked to report patients with (primary) severe acute liver injury (sALI) (international normalized ratio [INR] >1.5 but no hepatic encephalopathy) and primary ALF (INR >1.5 with overt hepatic encephalopathy) treated from 2008 to 2009. Data were analyzed from 46 patients with sALI and 109 patients with ALF.

RESULTS

The most frequent etiologies of primary ALF were non-acetaminophen drug-induced (32%), indeterminate (24%), and viral (21%); acetaminophen ingestion was the cause of ALF in only 9% of patients. The support of a ventilator was required by 44% of patients with ALF, vasopressors by 38%, and renal replacement by 36%. Seventy-nine patients with ALF (72%) survived until hospital discharge, 38 (35%) survived without emergency liver transplantation (ELT), and 51 received ELT (47%); 80% of patients who received ELT survived until discharge from the hospital.

CONCLUSIONS

In Germany, drug toxicity, indeterminate etiology, and viral hepatitis appear to be the major causes of primary ALF, which has high mortality. Patients with ALF are at great risk of progressing to multiple organ failure, but 80% of patients who receive ELT survive until discharge from the hospital.

Use of nucleoside (tide) analogues in patients with hepatitis B-related acute liver failure

BACKGROUND AND AIMS

The efficacy of nucleoside(tide) analogues (NA) in the treatment of acute liver failure due to hepatitis B virus (HBV-ALF) remains controversial. We determined retrospectively the impact of NAs in a large cohort of patients with HBV-ALF.

METHODS

The US Acute Liver Failure Study Group, a 23-site registry, prospectively enrolled 1,413 patients with ALF with different etiologies between 1998 and 2008. Of those, 105 patients were identified as HBV-ALF patients, of whom we excluded those without data on NA use or with co-infection with hepatitis C, leaving 85 patients, 43 of whom had received NA treatment. HBV-DNA on admission was quantified by real time polymerase chain reaction.

RESULTS

The treated and untreated groups were similar in most respects but differed significantly in regard to higher aminotransferase and bilirubin levels and hepatic coma grades, all being observed in the untreated group. Median duration of NA treatment was 6 days (range, 1-21 days). Overall survival in the NA treated and untreated groups were 61 and 64%, respectively (P = 0.72). Rates of transplant-free survival were 21 and 36% in the treated and untreated groups, respectively (P = 0.42). Multivariate analysis revealed that not using a NA [odds ratio (OR) 4.4, 95% CI 1.1-18.1, P = 0.041], hepatic coma grade I or II [OR 14.4, 95% CI 3.3-62.8, P < 0.001] and prothrombin time (PT) [OR 0.59, 95% CI 0.39-0.89, P = 0.012] were predictors of improved transplant-free survival.

CONCLUSIONS

Patients who are admitted with established HBV-ALF do not appear to benefit from viral suppression using nucleoside(tide) analogues presumably because of rapid disease evolution and short treatment duration. Despite the lack of benefit, NAs should still be given to transplantation candidates since viral suppression prevents recurrence after grafting.

Rapid generation of mature hepatocyte-like cells from human induced pluripotent stem cells by an efficient three-step protocol

Liver transplantation is the only definitive treatment for end-stage cirrhosis and fulminant liver failure, but the lack of available donor livers is a major obstacle to liver transplantation. Recently, induced pluripotent stem cells (iPSCs) derived from the reprogramming of somatic fibroblasts, have been shown to resemble embryonic stem (ES) cells in that they have pluripotent properties and the potential to differentiate into all cell lineages in vitro, including hepatocytes. Thus, iPSCs could serve as a favorable cell source for a wide range of applications, including drug toxicity testing, cell transplantation, and patient-specific disease modeling. Here, we describe an efficient and rapid three-step protocol that is able to rapidly generate hepatocyte-like cells from human iPSCs. This occurs because the endodermal induction step allows for more efficient and definitive endoderm cell formation. We show that hepatocyte growth factor (HGF), which synergizes with activin A and Wnt3a, elevates the expression of the endodermal marker Foxa2 (forkhead box a2) by 39.3% compared to when HGF is absent (14.2%) during the endodermal induction step. In addition, iPSC-derived hepatocytes had a similar gene expression profile to mature hepatocytes. Importantly, the hepatocyte-like cells exhibited cytochrome P450 3A4 (CYP3A4) enzyme activity, secreted urea, uptake of low-density lipoprotein (LDL), and possessed the ability to store glycogen. Moreover, the hepatocyte-like cells rescued lethal fulminant hepatic failure in a nonobese diabetic severe combined immunodeficient mouse model.

CONCLUSION

We have established a rapid and efficient differentiation protocol that is able to generate functional hepatocyte-like cells from human iPSCs. This may offer an alternative option for treatment of liver diseases.

Two distinct subtypes of hepatitis B virus-related acute liver failure are separable by quantitative serum immunoglobulin M anti-hepatitis B core antibody and hepatitis B virus DNA levels

Hepatitis B virus (HBV)-related acute liver failure (HBV-ALF) may occur after acute HBV infection (AHBV-ALF) or during an exacerbation of chronic HBV infection (CHBV-ALF). Clinical differentiation of the two is often difficult if a previous history of HBV is not available. Quantitative measurements of immunoglobulin M (IgM) anti-hepatitis B core antibody (anti-HBc) titers and of HBV viral loads (VLs) might allow the separation of AHBV-ALF from CHBV-ALF. Of 1,602 patients with ALF, 60 met clinical criteria for AHBV-ALF and 27 for CHBV-ALF. Sera were available on 47 and 23 patients, respectively. A quantitative immunoassay was used to determine IgM anti-HBc levels, and real-time polymerase chain reaction (rtPCR) was used to determine HBV VLs. AHBV-ALFs had much higher IgM anti-HBc titers than CHBV-ALFs (signal-to-noise [S/N] ratio median: 88.5; range, 0-1,120 versus 1.3, 0-750; P < 0.001); a cut point for a S/N ratio of 5.0 correctly identified 44 of 46 (96%) AHBV-ALFs and 16 of 23 (70%) CHBV-ALFs; the area under the receiver operator characteristic curve was 0.86 (P < 0.001). AHBV-ALF median admission VL was 3.9 (0-8.1) log10 IU/mL versus 5.2 (2.0-8.7) log10 IU/mL for CHBV-ALF (P < 0.025). Twenty percent (12 of 60) of the AHBV-ALF group had no hepatitis B surface antigen (HBsAg) detectable on admission to study, wheras no CHBV-ALF patients experienced HBsAg clearance. Rates of transplant-free survival were 33% (20 of 60) for AHBV-ALF versus 11% (3 of 27) for CHBV-ALF (P = 0.030).

CONCLUSIONS

AHBV-ALF and CHBV-ALF differ markedly in IgM anti-HBc titers, in HBV VLs, and in prognosis, suggesting that the two forms are, indeed, different entities that might each have a unique pathogenesis.

Use of Magnetocapsules for In Vivo Visualization and Enhanced Survival of Xenogeneic HepG2 Cell Transplants

Hepatocyte transplantation is currently being considered as a new paradigm for treatment of fulminant liver failure. Xeno- and allotransplantation studies have shown considerable success but the long-term survival and immunorejection of engrafted cells needs to be further evaluated. Using novel alginate-protamine sulfate-alginate microcapsules, we have co-encapsulated luciferase-expressing HepG2 human hepatocytes with superparamagnetic iron oxide nanoparticles to create magnetocapsules that are visible on MRI as discrete hypointensities. Magnetoencapsulated cells survive and secrete albumin for at least 5 weeks in vitro. When transplanted i.p. in immunocompetent mice, encapsulated hepatocytes survive for at least 4 weeks as determined using bioluminescent imaging, which is in stark contrast to naked, unencapsulated hepatocytes, that died within several days after transplantation. However, in vivo human albumin secretion did not follow the time course of magnetoencapsulated cell survival, with plasma levels returning to baseline values already at 1 week post-transplantation. The present results demonstrate that encapsulation can dramatically prolong survival of xenotransplanted hepatocytes, leading to sustained albumin secretion with a duration that may be long enough for use as a temporary therapeutic bridge to liver transplantation.

Pediatric end-stage liver disease score in acute liver failure to assess poor prognosis

BACKGROUND AND AIM

Although establishing accurate prognosis in acute liver failure (ALF) is of paramount importance, prognostic scoring systems still fail to achieve success. The pediatric end-stage liver disease (PELD) score has been used as a predictor of mortality in children with chronic liver disease listed for liver transplantation (LT); however, experience with the PELD score in ALF is limited. The goal of the present study was to investigate the prognostic accuracy of the PELD score in children with ALF.

PATIENTS AND METHODS

PELD score was calculated based on results of blood tests obtained at hospital admission from June 1999 to January 2009, in 40 consecutive patients younger than 18 years who presented with ALF. Poor outcome was defined as LT or death.

RESULTS

Mean (±SD) age of patients was 5.3 ± 4.4 years (range 6 months-17 years); 52.5% were girls (n = 21). Etiologies of ALF were hepatitis A in 42.5% (17), indeterminate in 35% (14), autoimmune hepatitis in 17.5% (type 1 12.5% [n5], type 2 5% [n2]), and toxic in 5% (2). Mean PELD score was 34.92 ± 10.48 (range 6-55). PELD scores obtained on admission were significantly higher among nonsurvivors (39.8 ± 9.5) and recipients of an LT (39 ± 7.1) compared with those who survived without LT (31.3 ± 3) (P < 0.001). A cutoff of 33 in PELD score using receiver operating characteristic curves showed 81% specificity and 86% sensitivity for poor outcome (positive predictive value 92% and negative predictive value 69%; area under curve 0.88 95% confidence interval 0.77-1.0; P < 0.0001).

CONCLUSIONS

PELD score obtained upon admission may be of help to establish the optimal timing for LT evaluation and listing. Further validation in larger and more diverse populations is needed.

Glycaemia as a sign of the viability of the foetuses in the last days of gestation in dairy goats with pregnancy toxaemia

Pregnancy toxaemia is one of the most common diseases affecting small ruminants in the last month of gestation. Nearly 80% of the foetal growth occurs in the last 6 weeks of gestation. Fat goats and goats carrying twins and triplets are at greater risk. Pregnancy toxaemia is characterized by metabolic acidosis, hypoglycaemia and ketonaemia and a very high mortality rate. In our study five does with pregnancy toxaemia showed a marked hyperglycaemia (12.4 ± 5.4 mmol/L). Although our findings are based on a small population sample (10 goats), we nonetheless postulate that hyperglycaemia could be explained by the death of the foetuses. Caesarian surgery was performed on four of the five does with hyperglycaemia (HG does). In the fifth, kidding was induced. In this group, two does had two dead foetuses, two had three dead foetuses and one does had four foetuses, only one of which was alive. Caesarian surgery was performed on all five does with hypoglycaemia (LG does). Four does of the LG group had three foetuses and one had two foetuses, all alive. The HG doe had lower rectal temperatures, lower sodium and higher urea nitrogen (BUN) in the blood when compared with the LG does. As the condition of affected does may deteriorate quickly, the results of the present study suggest that in the last days of pregnancy goats with pregnancy toxaemia and concurrent hypoglycaemia should be considered for caesarian surgery.

Inhibition of GHRH aggravated acetaminophen-induced acute mice liver injury through GH/IGF-I axis

The aim of the current study is to investigate the effects of growth hormone releasing hormone (GHRH) antagonist on acetaminophen (APAP)-induced acute liver injury in mice. Healthy C57/B6L mice were orally treated with 200 mg/kg APAP with or without a 30-min pre-treatment with 300 µg/kg GHRH antagonist MZ-5-156. After 12 hours, serum, plasma, and liver samples from each mouse were collected for analyses. Our results showed that twelve-hour treatment with APAP caused obvious liver injury, elevated serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, increased oxidative stress, reduced expressions of antioxidant enzymes, accumulated expression of pro-inflammatory cytokines, and increased circulating levels of growth hormone (GH) and insulin-like growth factor-I (IGF-I). Pre-treatment with MZ-5-156 aggravated liver injury, further increased serum ALT and AST levels, exacerbated oxidative stress and inflammation induced by APAP. Treatment of MZ-5-156 also blocked the phosphorylation form and total form of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5). Treatment of GHRH super-agonist JI-38 immediately after MZ-5-156 treatment partly reversed the liver injury caused by APAP and MZ-5-156. In conclusion, GHRH plays essential protective role in APAP-induced acute liver injury in vivo. The protective properties of GHRH are partially through GH/IGF-I axis and JAK/STAT pathway.

Fulminant liver failure models with subsequent encephalopathy in the mouse

BACKGROUND

A reliable model of fulminant liver failure (FLF) is urgently required in this research field. This study aimed to develop a murine FLF model.

METHODS

We used three groups of male C57BL/6 mice: control, with azoxymethane treatment (AOM group), and with galactosamine and tumor necrosis factor-alpha treatment (Gal+TNF-alpha group). The effects of body temperature (BT) control on survival in all three groups were investigated. Using BT control, we compared the survival, histopathological findings and biochemical/coagulation profiles between the two experimental groups. The effects of hydration on international normalized ratios of prothrombin time (PT-INRs) were also checked. Dose-dependent survival curves were constructed for both experimental groups. Neurological behavior was assessed using a coma scale.

RESULTS

No unexpected BT effects were seen in the control group. The AOM group, but not the Gal+TNF-alpha group, showed a significant difference in survival curves between those with and without BT care. Histopathological assessment showed consistent FLF findings in both experimental groups with BT care. There were significant differences between the experimental groups in aspartate aminotransferase levels and PT-INRs, and significant differences in PT-INRs between the sufficiently and insufficiently hydrated groups. There were significant differences between FLF models in the duration of each coma stage, with significant differences in stages 1 and 3 as percentages of the disease state (stages 1-4). The two FLF models with BT care showed different survival curves in the dose-dependent survival study.

CONCLUSIONS

AOM provides a good FLF model, but requires a specialized environment and careful BT control. Other FLF models may also be useful, depending on the research purpose. Thoughtful attention to caregiving and close observation are indispensable for successful FLF models.

Developmental and disease-related influences on self-management acquisition among pediatric liver transplant recipients

Pediatric LT recipients are vulnerable to disruptions in their healthcare management and transitioning to self-managed care. This study aimed to examine whether age at transplant and indication for transplant (acute vs. chronic liver disease) influence later self-management skills. Sixty-three LT recipients, aged 14 and older (M = 17.68, s.d. = 3.01), were recruited and asked to complete a healthcare management survey, the Developmentally Based Skills Checklist, adapted for transplant patients, listing 22 behaviors that medically ill adolescents should progressively master. While there were no significant differences between those who received an LT owing to an acute disease vs. those who received an LT owing to a chronic disease, the age at which patients received their transplant did yield significant results, although, overall, these findings were attenuated by current age. However, our findings indicated that males transplanted at a younger age struggled with mastery over their healthcare responsibilities relative to males transplanted later and females in both age groups. There are many possible reasons why the experience of transplant at a younger age could negatively affect or derail healthcare transitions. Future research is necessary to further untangle this relationship; yet, it seems as though longer time living with LT may make transition harder for families.

[Pharmacological treatment of acute hepatitis B]

The incidence of acute B hepatitis is decreasing due to socioeconomical changes and the implementation of vaccination programs. Nevertheless it is potentially severe, causing approximately 30% of acute liver failures in Spain. Pharmacological treatment of acute B hepatitis has become a matter of issue over the last decade. This text offers a review of the published data and international guidelines. Most published studies have a low methodological quality and lamivudine was used as treatment in all of them. A survival improvement with prompt treatment has been shown in acute liver injury and probably in severe acute hepatitis (total bilirubin>10mg/dl and INR>1.5). International guidelines support treatment in these cases, but there is no consensus on the drug to use or the length of treatment.

Characterization and outcomes of young infants with acute liver failure

OBJECTIVE

To characterize infants aged ≤ 90 days enrolled in an international, multicenter, prospective registry of children aged < 18 years with acute liver failure (ALF).

STUDY DESIGN

The Pediatric Acute Liver Failure (PALF) Study Group collects prospective data on children from birth to 18 years. We analyzed data from infants aged ≤ 90 days enrolled in the PALF Study before May 18, 2009.

RESULTS

A total of 148 infants were identified in the PALF registry (median age, 18 days). Common etiologies of ALF were indeterminate (38%), neonatal hemochromatosis (13.6%), and herpes simplex virus (12.8%). Spontaneous survival occurred in 60% of the infants, 16% underwent liver transplantation, and 24% died without undergoing liver trsansplantation. Infants with indeterminate ALF were more likely to undergo liver transplantation than those with viral-induced ALF (P = .0002). The cumulative incidence of death without liver transplantation was higher in infants with viral ALF (64%) compared with those with neonatal hemochromatosis (16%) or indeterminate ALF (14%) (P = .0007).

CONCLUSION

ALF in young infants presents unique diagnostic considerations. Spontaneous survival is better than previously thought. Liver transplantation provides an additional option for care.

Acute liver failure in Scotland between 1992 and 2009; incidence, aetiology and outcome

AIM

To describe incidence, aetiology and outcome data for Scotland since the inception of the Scottish Liver Transplant Unit (SLTU) in 1992.

BACKGROUND

Acute liver failure (ALF) is a rare but frequently fatal condition. Few studies have adequate patient numbers to draw convincing conclusions over demographic features, aetiology and outcome.

DESIGN

Statistical analysis of prospectively collected data on aetiology, demographic, clinical and outcome of all admissions, including those with ALF, to the SLTU.

METHODS

Incidence data presented for admissions and ALF. Descriptive frequencies for aetiology, clinical, demographic and outcome data presented; including split analysis for paracetamol and non-paracetamol aetiologies. Univariate and multivariate analysis of admission factors predictive of outcome is described.

RESULTS

Nine hundred and forty-nine patients were admitted to the SLTU between 1992 and 2009. Five hundred and twenty-four patients had ALF. The annual incidence of ALF in the Scottish population is 0.62 per 100,000 and paracetamol overdose (POD) was the largest causative factor; responsible for 0.43 cases of ALF per 100,000 population per year. The odds ratio (OR) of transplantation or death was 0.47 in the POD group compared to other aetiologies; yet of not being a transplant candidate having met the Kings College Hospital poor prognostic criteria OR was 4.9. Of admissions listed for transplant 76.0% were transplanted. Of those listed and not transplanted mortality was approaching 100% and 76.1% of those transplanted survived to discharge.

CONCLUSION

This large, prospective, single centre study with a defined geographical area and well-recorded population provides accurate data regarding ALF between 1992 and 2009.

A Src family kinase inhibitor improves survival in experimental acute liver failure associated with elevated cerebral and circulating vascular endothelial growth factor levels

BACKGROUND AND AIMS

Acute liver failure (ALF) is frequently complicated by cerebral oedema, systemic inflammation and multiorgan dysfunction. Vascular endothelial growth factor (VEGF) may stimulate liver regeneration but it can also be pro-inflammatory, activating endothelial cells and increasing permeability, actions mediated through Src kinase signalling. We therefore examined whether a Src inhibitor could have therapeutic potential in ALF.

METHODS

Murine ALF was induced with azoxymethane. Liver pathology was graded by a blinded examiner and apoptosis quantified by immunohistochemistry. Cerebral VEGF expression was imaged using VEGF-green fluorescent protein transgenic mice. Circulating and macrophage-secreted VEGF levels were measured. Experimental animals received a Src inhibitor or vehicle controls.

RESULTS

VEGF was undetectable in normal plasma but reached a mean of 835 pg/ml at grade III encephalopathy (P<0.001). Ammonia, lipopolysaccharide and interferon-gamma acted synergistically to enhance VEGF secretion by macrophages. Production of VEGF by cerebral cortical astrocytes increased with disease progression. Late treatment with inhibitors of Src or VEGF did not improve liver histology, encephalopathy or survival. However, early use of a Src kinase inhibitor significantly reduced hepatic injury, delayed encephalopathy and allowed 25% of mice to survive an otherwise lethal insult.

CONCLUSION

Systemic and cerebral VEGF levels are significantly elevated during experimental ALF and may be exacerbated by hyperammonemia and macrophage activation. Early use of a Src inhibitor reduced hepatocellular injury and enabled survival, indicating such agents may have some promise in the treatment of ALF.

Effect of ω-3 polyunsaturated fatty acids on hepatic tight junctions and liver regeneration in rats after partial hepatectomy

AIM: To investigate the effect of ω-3 polyunsaturated fatty acids (PUFAs) on hepatic tight junctions and liver regeneration in rats after partial hepatectomy (PH)

METHODS: A rat model of 70% PH was used in this study. Eighty male SD rats were randomly divided into sham operation group, PH group, PH + low-dose ω-3 PUFA (1 mL/kg) group and PH + high-dose ω-3 PUFA (2 mL/kg) group. Serum samples were collected to measure the levels of total bile acids, total bilirubin, alanine aminotransferase (ALT) and albumin on days 1, 2, 3 and 5 after PH. Tissue samples were collected for detecting the expression of hepatic tight junction proteins (Occludin, Claudin-3 and ZO-1) and PCNA (a parameter reflecting liver regeneration) by Western blot. Tissue samples were also collected for observation of structural changes in hepatic tight junctions by confocal microscopy.

RESULTS: In comparison with the PH group on day 1, the levels of total bile acids (181.2 ± 63.9, 166.7 ± 68.9 vs 228.9 ± 37.7), total bilirubin (13.5 ± 8.8, 7.6 ± 0.1 vs 25.9 ± 15.3) and ALT (1042.2 ± 179.7, 901.4 ± 182.3 vs 2703.9 ± 130.0) decreased significantly in the low- and high-dose ω-3 PUFA groups (all P < 0.05), whereas no marked changes in the level of albumin (27.2 ± 1.1, 29.8 ± 0.9 vs 30.5 ± 1.2) were observed. Compared to the PH group on day 2, a significant decrease in the levels of total bilirubin (6.8 ± 9.2, 6.1 ± 2.0 vs 17.7 ± 1.1) and ALT (452.8 ± 258.5, 499.8 ± 155.9 vs 1 466.5 ± 30.2) was noted in the low- and high-dose ω-3 PUFA groups (all P < 0.05), whereas no marked changes in the level of albumin (26.8 ± 0.4, 27.7 ± 1.0 vs 25.7 ± 0.6) were observed. The expression of hepatic tight junction proteins (Occludin, Claudin-3 and ZO-1) increased significantly on days 1, 2 and 5 after PH (all P < 0.05), and liver regeneration was enhanced significantly on days 1, 2, 3 and 5 after PH (all P < 0.05). Treatment with ω-3 PUFAs promoted structural restoration of hepatic tight junctions.

CONCLUSION: ω-3 PUFAs not only promote the expression of tight junction proteins and protect the structure of hepatic tight junctions but also promote liver regeneration and protect liver function in rats after PH.

Neurological management of fulminant hepatic failure

Acute liver failure (ALF) is uncommon in the United States, but presents acutely and catastrophically, often with deadly consequences. Hepatic encephalopathy, cerebral edema, elevated intracranial pressure, and intracranial hemorrhage due to coagulopathy are common occurrences in patients with ALF. Appropriate management of multi-system organ failure and neurological complications are essential in bridging patients to transplant and ensuring satisfactory outcomes.

Acute liver failure because of chronic lymphocytic leukemia: case report and review of the literature

Infiltration of the liver by hematologic malignancies is an uncommon cause of liver failure. B-Cell chronic lymphocytic leukemia (cll) is a usually indolent disease that may infiltrate the liver, but based on a review of the literature, has never been reported to induce acute liver failure. Here, we describe the case of a 78-year-old woman with acute liver failure secondary to infiltration with cll being unresponsive to chemotherapy and causing death. This case is notable because of its atypical presentation and ultimate poor prognosis.

Granulocyte colony-stimulating factor treatment ameliorates liver injury and improves survival in rats with D-galactosamine-induced acute liver failure

Only liver transplantation is currently available therapy for the patients with acute liver failure (ALF). This study was designed to determine whether administration of granulocyte colony-stimulating factor (G-CSF) has therapeutic efficacy in animals with ALF. Female Sprague-Dawley (SD) rats were intraperitoneally injected with a single dose of d-galactosamine (d-GalN, 1.4g/kg) to induce ALF. After 2h, the rats were randomized to receive G-CSF (50μg/kg/day), or saline vehicle injection for 5 days. Rats were observed for survival and assessed for liver injury by serum alanine transaminase (ALT) measurement and histological analysis. CD34+ cells in bone marrow were assessed by flow cytometry. CD34+ cells and Ki-67+ hepatocytes in liver tissue were evaluated by immunohistochemistry. In the ALF model, 5-day survival after d-GalN injection was 33.3% (10/30), while G-CSF administration following d-GalN resulted in 53.3% (16/30) survival (p=0.027). G-CSF treated rats had lower ALT level and less hepatic injury compared with saline vehicle rats. The increases of CD34+ cells in bone marrow and liver tissue and Ki-67+ cells in liver tissue in G-CSF treated rats were higher than those in saline rats. No correlation was observed between CD34+ cells and Ki-67+ hepatocytes in liver tissue in both G-CSF and vehicle rats. It is suggested that G-CSF increases survival rate, decreases liver injury and enhances hepatocyte proliferation in rats with d-GalN-induced ALF possibly through actions including but not limiting to CD34+ cell mobilization, and that G-CSF may be of potential value in treating ALF.

Management of sepsis during MARS treatment in acute on chronic liver failure

INTRODUCTION

The aim of our study was a 30-day follow-up of the use of early detection of endotoxin by the endotoxin activity assay (EAA) for patients with acute liver failure superimposed on chronic liver disease (AoCLF) and treated with polymyxin-B hemoperfusion-based (PMX-DHP) treatment and albumin dialysis in the molecular adsorbent recirculating system (MARS).

MATERIALS AND METHODS

From February 2008 to July 2010, we evaluated 10 AoCLF patients experiencing systemic inflammatory response syndrome (SIRS) in association with suspected infection and an EAA-positive test (>0.60). These patients awaiting liver transplantation (OLT) showed similar Model End-Stage Liver Disease (MELD) scores (range, 19-25) and encephalopathy grade ≤ 2. Five patients received therapy to remove endotoxins with PMX-DHP with MARS treatment for liver failure (group A); the other 5 patients received MARS treatment only (group B).

RESULTS

Two PMX-DHP treatments were performed in 4 group A patients (average EA=0.66 [range, 0.61-0.70]) and 3 treatments for 1 patient (EA=0.92). All 5 subjects underwent an average of 4 MARS treatments (range, 3-5). At the end of therapy, the median EA level was 0.42 (range, 0.37-0.48). As reported in the literature, we achieved a significant improvement in liver and kidney functions using MARS. Measurements of lactate, interleukin (IL)-6, and tumor necrosis factor (TNF)-α were significantly improved among patients treated with the extracorporeal therapies. At 30 days of observation, all 5 patients treated with MARS plus PMX-DHP are alive. In group B, a mean of 7.5 MRAS treatments were performed. We observed an improvement in hemodynamic and liver functions with reduced levels of proinflammatory cytokines and lactates in 4 patients. One patient showed no improvement in clinical status with the development of sepsis and subsequent multiorgan failure after 24 days.

CONCLUSION

The possibility of an early diagnosis using the EAA in AoCLF patients could prevent the progression of the sepsis cascade. The use of PMX-DHP and MARS in these patients, could lead to resolution of clinical status in a short time.

Value of KCH criteria, MELD score and MELDNa score for prediction of prognosis of acute liver failure

AIM: To investigate the value of King's College Hospital (KCH) criteria, Model for End-stage Liver Disease (MELD) score and MELD with incorporation of serum sodium (MELDNa) score for evaluation of prognosis of acute liver failure.

METHODS: A total of 37 consecutive patients with acute liver failure (ALF) were included in the study and divided into two groups according to the prognosis. Areas under the receiver operating characteristic curve (AUC-ROC) of MELD, MELDNa and KCH criteria were used to assess the prognosis of patients with ALF.

RESULTS: The mortality of ALF was 70.3% in this study. MELD and MELDNa scores were significantly higher in the death group than in the survival group (43.8 ± 11.0 vs 31.0 ± 5.4, 43.4 ± 9.9 vs 32.1 ± 5.0, both P < 0.05). AUC-ROC of MELD score, MELDNa score and KCH criteria was 0.858 (0.704-0.950), 0.867 (0.715-0.955), and 0.645 (0.471-0.795), respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (+LR) of MELD score were the same as those of MELDNa score but higher than those of KCH criteria (84.6 vs 65.4, 81.8 vs 63.6, 91.7 vs 81.0, 69.2 vs 43.7, 4.65 vs 1.80).

CONCLUSION: MELD, MELDNa scores and KCH criteria have appreciable value to evaluate the prognosis of ALF patients. MELD and MELDNa scores are more accurate than KCH criteria in assessing prognosis of ALF patients.

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.

Stem cells in acute liver failure

Patients with acute liver failure are a particularly challenging group, with unique difficulties faced in treatment decisions. Life-saving therapy is available, but organ shortage, delays in transplantation, and complications in management result in a high mortality in this group of patients even after transplant. Any pharmacologic intervention that improved outcomes in this population of critically ill patients would be of great benefit. Based on available evidence, different scenarios of participation of HSCs in liver recovery are conceivable. Encouraging HSCs to differentiate into hepatocytes or supply paracrine and cellular level support to accelerate ongoing local repair mechanisms and assist a failing liver with inadequate mass and functional capacity might be directed to occur effectively in humans. Evidence within small animal models of liver injury and observations within the human population suggest that this might also be encouraged. The use of pharmacologic agents to mobilize hematopoietic stem cells is well established and effectively used in a different population of patients. As such, extending the use of these drugs, such as plerixafor, to the human population has a sound basis. However, there is a need for clarification of the mechanisms by which these cells exert their effect as well as which specific population of cells is involved in the regenerative process. To be clinically relevant in scenarios of acute liver failure, stem cell mobilizing strategies would have to impact survival when administered well after injury. Applications in other settings may also prove useful. Limits to liver resection exist where the size of the future liver remnant governs the extent of resection possible. Preexisting functional impairment may be restrictive, and strategies involving stem cells may assist the future liver remnant in both normal and functionally impaired livers. Benefit has already been reported from treatment with G-CSF in other injured tissues, including the injured myocardium and acutely injured kidney. However, as yet no clinical trial exists to assess the effects of stem cell mobilization in humans with acute liver failure. The familiarity in the use of and success demonstrated in the clinical and experimental use of plerixafor and G-CSF make exploration of hematopoietic stem cells as therapy in patients with acute liver failure appealing.

Indications and contraindications for liver transplantation

Patients with chronic liver disease and certain patients with acute liver failure require liver transplantation as a life-saving measure. Liver transplantation has undergone major improvements, with better selection of candidates for transplantation and allocation of scarce deceased donor organs (according to more objective criteria). Living donor liver transplantation came into existence to overcome the shortage of donor organs especially in countries where there was virtually no deceased donor programme. Advances in the technical aspects of the procedure, the intraoperative and postoperative care of both recipients and donors, coupled with the introduction of better immunosuppression protocols, have led to graft and patient survivals of over 90% in most high volume centres. Controversial areas like transplantation in alcoholic liver disease without abstinence, acute alcoholic hepatitis, and retransplantation for recurrent hepatitis C virus infection require continuing discussion.

Astrocyte glutamine synthetase: importance in hyperammonemic syndromes and potential target for therapy

Many theories have been advanced to explain the encephalopathy associated with chronic liver disease and with the less common acute form. A major factor contributing to hepatic encephalopathy is hyperammonemia resulting from portacaval shunting and/or liver damage. However, an increasing number of causes of hyperammonemic encephalopathy have been discovered that present with the same clinical and laboratory features found in acute liver failure, but without liver failure. Here, we critically review the physiology, pathology, and biochemistry of ammonia (i.e., NH3 plus NH4+) and show how these elements interact to constitute a syndrome that clinicians refer to as hyperammonemic encephalopathy (i.e., acute liver failure, fulminant hepatic failure, chronic liver disease). Included will be a brief history of the status of ammonia and the centrality of the astrocyte in brain nitrogen metabolism. Ammonia is normally detoxified in the liver and extrahepatic tissues by conversion to urea and glutamine, respectively. In the brain, glutamine synthesis is largely confined to astrocytes, and it is generally accepted that in hyperammonemia excess glutamine compromises astrocyte morphology and function. Mechanisms postulated to account for this toxicity will be examined with emphasis on the osmotic effects of excess glutamine (the osmotic gliopathy theory). Because hyperammonemia causes osmotic stress and encephalopathy in patients with normal or abnormal liver function alike, the term "hyperammonemic encephalopathy" can be broadly applied to encephalopathy resulting from liver disease and from various other diseases that produce hyperammonemia. Finally, the possibility that a brain glutamine synthetase inhibitor may be of therapeutic benefit, especially in the acute form of liver disease, is discussed.

Fulminant hepatic failure in a patient with advanced extragonadal germ cell tumour

Fulminant hepatic failure (FHF) in association with metastatic cancer, without evidence of liver metastases, has not been previously reported in the literature. This report concerns a case of FHF in a 36-year-old man with advanced germ cell tumour arising from an extragonadal (retroperitoneal) primary. Liver function and encephalopathy improved following chemotherapy, suggesting prompt diagnosis and treatment may have cured the patient. Following completion of chemotherapy, he developed spontaneous bacterial endocarditis, requiring aortic valve replacement, a rare complication of curative chemotherapy. At 44 months post completion of chemotherapy, he has regained his premorbid performance status and has returned to work.