Etiology and outcome for 295 patients with acute liver failure in the United States

A virtual scalable model of the Hepatic Lobule for acetaminophen hepatotoxicity prediction

Addressing drug-induced liver injury is crucial in drug development, often causing Phase III trial failures and market withdrawals. Traditional animal models fail to predict human liver toxicity accurately. Virtual twins of human organs present a promising solution. We introduce the Virtual Hepatic Lobule, a foundational element of the Living Liver, a multi-scale liver virtual twin. This model integrates blood flow dynamics and an acetaminophen-induced injury model to predict hepatocyte injury patterns specific to patients. By incorporating metabolic zonation, our predictions align with clinical zonal hepatotoxicity observations. This methodology advances the development of a human liver virtual twin, aiding in the prediction and validation of drug-induced liver injuries.

Early brain neuroinflammatory and metabolic changes identified by dual tracer microPET imaging in mice with acute liver injury

Background

Acute liver injury (ALI) that progresses into acute liver failure (ALF) is a life-threatening condition with an increasing incidence and associated costs. Acetaminophen (N-acetyl-p-aminophenol, APAP) overdosing is among the leading causes of ALI and ALF in the Northern Hemisphere. Brain dysfunction defined as hepatic encephalopathy is one of the main diagnostic criteria for ALF. While neuroinflammation and brain metabolic alterations significantly contribute to hepatic encephalopathy, their evaluation at early stages of ALI remained challenging. To provide insights, we utilized post-mortem analysis and non-invasive brain micro positron emission tomography (microPET) imaging of mice with APAP-induced ALI.

Methods

Male C57BL/6 mice were treated with vehicle or APAP (600 mg/kg, i.p.). Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver damage (using H&E staining), hepatic and serum IL-6 levels, and hippocampal IBA1 (using immunolabeling) were evaluated at 24h and 48h. Vehicle and APAP treated animals also underwent microPET imaging utilizing a dual tracer approach, including [11C]-peripheral benzodiazepine receptor ([11C]PBR28) to assess microglia/astrocyte activation and [18F]-fluoro-2-deoxy-2-D-glucose ([18F]FDG) to assess energy metabolism. Brain images were pre-processed and evaluated using conjunction and individual tracer uptake analysis.

Results

APAP-induced ALI and hepatic and systemic inflammation were detected at 24h and 48h by significantly elevated serum ALT and AST levels, hepatocellular damage, and increased hepatic and serum IL-6 levels. In parallel, increased microglial numbers, indicative for neuroinflammation were observed in the hippocampus of APAP-treated mice. MicroPET imaging revealed overlapping increases in [11C]PBR28 and [18F]FDG uptake in the hippocampus, thalamus, and habenular nucleus indicating microglial/astroglial activation and increased energy metabolism in APAP-treated mice (vs. vehicle-treated mice) at 24h. Similar significant increases were also found in the hypothalamus, thalamus, and cerebellum at 48h. The individual tracer uptake analyses (APAP vs vehicle) at 24h and 48h confirmed increases in these brain areas and indicated additional tracer- and region-specific effects including hippocampal alterations.

Conclusion

Peripheral manifestations of APAP-induced ALI in mice are associated with brain neuroinflammatory and metabolic alterations at relatively early stages of disease progression, which can be non-invasively evaluated using microPET imaging and conjunction analysis. These findings support further PET-based investigations of brain function in ALI/ALF that may inform timely therapeutic interventions.

The Role of Mechanistic Biomarkers in Understanding Acetaminophen Hepatotoxicity in Humans

Our understanding of the fundamental molecular mechanisms of acetaminophen (APAP) hepatotoxicity began in 1973 to 1974, when investigators at the US National Institutes of Health published seminal studies demonstrating conversion of APAP to a reactive metabolite that depletes glutathione and binds to proteins in the liver in mice after overdose. Since then, additional groundbreaking experiments have demonstrated critical roles for mitochondrial damage, oxidative stress, nuclear DNA fragmentation, and necrotic cell death as well. Over the years, some investigators have also attempted to translate these mechanisms to humans using human specimens from APAP overdose patients. This review presents those studies and summarizes what we have learned about APAP hepatotoxicity in humans so far. Overall, the mechanisms of APAP hepatotoxicity in humans strongly resemble those discovered in experimental mouse and cultured hepatocyte models, and emerging biomarkers also suggest similarities in liver repair. The data not only validate the first mechanistic studies of APAP-induced liver injury performed 50 years ago but also demonstrate the human relevance of numerous studies conducted since then. SIGNIFICANCE STATEMENT: Human studies using novel translational, mechanistic biomarkers have confirmed that the fundamental mechanisms of acetaminophen (APAP) hepatotoxicity discovered in rodent models since 1973 are the same in humans. Importantly, these findings have guided the development and understanding of treatments such as N-acetyl-l-cysteine and 4-methylpyrazole over the years. Additional research may improve not only our understanding of APAP overdose pathophysiology in humans but also our ability to predict and treat serious liver injury in patients.

Growing Evidence for Survival Benefit with Plasma Exchange to Treat Liver Failure

Plasma exchange (PLEX) to treat liver failure patients is gaining increasing momentum in recent years. Most reports have used PLEX to treat patients with acute liver failure (ALF) or acute on chronic liver failure (ACLF). Etiology of liver disease has an important bearing on the prognosis of the illness in these patients. The accruing data suggest survival benefit with PLEX compared with standard medical treatment to treat ALF and ACLF patients, in randomised controlled trials done world-over. The American College of Apheresis now recommends high-volume PLEX as first-line treatment for ALF patients. Most matched cohort studies done from India which recruited patients with a specific etiology of ALF or ACLF report survival benefit with PLEX compared to standard medical treatment. The survival benefit with PLEX appears more pronounced in ALF patients rather than in ACLF patients. Systematic analysis of the efficacy of PLEX to treat ALF and ACLF patients is needed. There is also a need to identify dynamic predictive scores to assess which patients with ALF or ACLF will respond to PLEX.

Evaluation of drug-induced liver toxicity of trovafloxacin and levofloxacin in a human microphysiological liver model

Drug-induced liver injury induced by already approved substances is a major threat to human patients, potentially resulting in drug withdrawal and substantial loss of financial resources in the pharmaceutical industry. Trovafloxacin, a broad-spectrum fluoroquinolone, was found to have unexpected side effects of severe hepatotoxicity, which was not detected by preclinical testing. To address the limitations of current drug testing strategies mainly involving 2D cell cultures and animal testing, a three-dimensional microphysiological model of the human liver containing expandable human liver sinusoidal endothelial cells, monocyte-derived macrophages and differentiated HepaRG cells was utilized to investigate the toxicity of trovafloxacin and compared it to the structurally-related non-toxic drug levofloxacin. In the model, trovafloxacin elicited vascular and hepatocellular toxicity associated with pro-inflammatory cytokine release already at clinically relevant concentrations, whereas levofloxacin did not provoke tissue injury. Similar to in vivo, cytokine secretion was dependent on a multicellular immune response, highlighting the potential of the complex microphysiological liver model for reliably detecting drug-related cytotoxicity in preclinical testing. Moreover, hepatic glutathione depletion and mitochondrial ROS formation were elucidated as intrinsic toxicity mechanisms contributing to trovafloxacin toxicity.

Liver-specific metastases as an independent prognostic factor in cancer patients receiving hospice care in hospital

BACKGROUND

Survival prediction is important in cancer patients receiving hospice care. Palliative prognostic index (PPI) and palliative prognostic (PaP) scores have been used to predict survival in cancer patients. However, cancer primary site with metastatic status, enteral feeding tubes, Foley catheter, tracheostomy, and treatment interventions are not considered in aforementioned tools. The study aimed to investigate the cancer features and potential clinical factors other than PPI and PaP to predict patient survival.

METHODS

We conducted a retrospective study for cancer patients admitted to a hospice ward between January 2021 and December 2021. We examined the correlation of PPI and PaP scores with survival time since hospice ward admission. Multiple linear regression was used to test the potential clinical factors other than PPI and PaP for predicting survival.

RESULTS

A total of 160 patients were enrolled. The correlation coefficients for PPI and PaP scores with survival time were -0.305 and -0.352 (both p < 0.001), but the predictabilities were only marginal at 0.087 and 0.118, respectively. In multiple regression, liver metastasis was an independent poor prognostic factor as adjusted by PPI (β = -8.495, p = 0.013) or PaP score (β = -7.139, p = 0.034), while feeding gastrostomy or jejunostomy were found to prolong survival as adjusted by PPI (β = 24.461, p < 0.001) or PaP score (β = 27.419, p < 0.001).

CONCLUSIONS

Association between PPI and PaP with patient survival in cancer patients at their terminal stages is low. The presence of liver metastases is a poor survival factor independent of PPI and PaP score.

Long-term outcomes of pediatric liver transplantation in acute liver failure vs end-stage chronic liver disease: A retrospective observational study

BACKGROUND

Children with acute liver failure (ALF) who meet the criteria are eligible for super-urgent transplantation, whereas children with end-stage chronic liver disease (ESCLD) are usually transplanted electively. Pediatric liver transplantation (PLT) in ALF and ESCLD settings has been well described in the literature, but there are no studies comparing the outcomes in these two groups.

AIM

To determine if there is a difference in post-operative complications and survival outcomes between ALF and ESCLD in PLT.

METHODS

This was a retrospective observational study of all primary PLTs performed at a single center between 2000 and 2019. ALF and ESCLD groups were compared for pretransplant recipient, donor and operative parameters, and post-operative outcomes including graft and patient survival.

RESULTS

Over a 20-year study period, 232 primary PLTs were performed at our center; 195 were transplanted for ESCLD and 37 were transplanted for ALF. The ALF recipients were significantly older (median 8 years vs 5.4 years; P = 0.031) and heavier (31 kg vs 21 kg; P = 0.011). Living donor grafts were used more in the ESCLD group (34 vs 0; P = 0.006). There was no difference between the two groups concerning vascular complications and rejection, but there were more bile leaks in the ESCLD group. Post-transplant patient survival was significantly higher in the ESCLD group: 1-, 5-, and 10-year survival rates were 97.9%, 93.9%, and 89.4%, respectively, compared to 78.3%, 78.3%, and 78.3% in the ALF group (P = 0.007). However, there was no difference in 1-, 5-, and 10-year graft survival between the ESCLD and ALF groups (90.7%, 82.9%, 77.3% vs 75.6%, 72.4%, and 66.9%; P = 0.119).

CONCLUSION

Patient survival is inferior in ALF compared to ESCLD recipients; the main reason is death in the 1^st year post-PLT in ALF group. Once the ALF children overcome the 1^st year after transplant, their survival stabilizes, and they have good long-term outcomes.

Paracetamol (acetaminophen) overdose and hepatotoxicity: mechanism, treatment, prevention measures, and estimates of burden of disease

INTRODUCTION

Paracetamol is one of the most used medicines worldwide and is the most common important poisoning in high-income countries. In overdose, paracetamol causes dose-dependent hepatotoxicity. Acetylcysteine is an effective antidote, however despite its use hepatotoxicity and many deaths still occur.

AREAS COVERED

This review summarizes paracetamol overdose and toxicity (including mechanisms, risk factors, risk assessment, and treatment). In addition, we summarize the epidemiology of paracetamol overdose worldwide. A literature search on PubMed for poisoning epidemiology and mortality from 1 January 2017 to 26 October 2022 was performed to estimate rates of paracetamol overdose, liver injury, and deaths worldwide.

EXPERT OPINION

Paracetamol is widely available and yet is substantially more toxic than other analgesics available without prescription. Where data were available, we estimate that paracetamol is involved in 6% of poisonings, 56% of severe acute liver injury and acute liver failure, and 7% of drug-induced liver injury. These estimates are limited by lack of available data from many countries, particularly in Asia, South America, and Africa. Harm reduction from paracetamol is possible through better identification of high-risk overdoses, and better treatment regimens. Large overdoses and those involving modified-release paracetamol are high-risk and can be targeted through legislative change.

Immunomodulation by Hemoadsorption—Changes in Hepatic Biotransformation Capacity in Sepsis and Septic Shock: A Prospective Study

Background: Sepsis is often associated with liver dysfunction, which is an indicator of poor outcomes. Specific diagnostic tools that detect hepatic dysfunction in its early stages are scarce. So far, the immune modulatory effects of hemoadsorption with CytoSorb^® on liver function are unclear. Method: We assessed the hepatic function by using the dynamic LiMAx^® test and biochemical parameters in 21 patients with sepsis or septic shock receiving CytoSorb^® in a prospective, observational study. Points of measurement: T₁: diagnosis of sepsis or septic shock; T₂ and T₃: 24 h and 48 h after the start of CytoSorb^®; T₄: 24 h after termination of CytoSorb^®. Results: The hepatic biotransformation capacity measured by LiMAx^® was severely impaired in up to 95 % of patients. Despite a rapid shock reversal under CytoSorb^®, a significant improvement in LiMAx^® values appeared from T₃ to T₄. This decline and recovery of liver function were not reflected by common parameters of hepatic metabolism that remained mostly within the normal range. Conclusions: Hepatic dysfunction can effectively and safely be diagnosed with LiMAx^® in ventilated ICU patients under CytoSorb^®. Various static liver parameters are of limited use since they do not adequately reflect hepatic dysfunction and impaired hepatic metabolism.

Probiotics: Evolving as a Potential Therapeutic Option against Acetaminophen-Induced Hepatotoxicity

Acetaminophen (APAP) is the most common prescription medicine around the world for the treatment of pain and fever and is considered to be a safe drug at its therapeutic dose. However, a single overdose or frequent use of APAP can cause severe acute liver injury. APAP hepatotoxicity is a prevalent cause of acute liver disease around the world and the lack of suitable treatment makes it a serious problem. In recent years, there has been a surge in interest in using probiotics and probiotic-derived products, known as postbiotics, as health and disease negotiators. A growing body of evidence revealed that they can be equally effective against APAP hepatotoxicity. Different probiotic bacteria were found to be pre-clinically effective against APAP hepatotoxicity. Different postbiotics have also shown exciting results in preclinical models of APAP hepatotoxicity. This review summarized the protective roles and mechanisms of the different probiotic bacteria and postbiotics against APAP hepatotoxicity, with critical discussion. A brief discussion on potential novel probiotics and postbiotics for oxidative liver injury was also included. This review was written in an attempt to pique the interest of researchers in developing a safe therapeutic option against oxidative liver damage using probiotics and/or postbiotics as dietary supplements.

Pediatric acute liver failure: An experience of a pediatric intensive care unit from resource limited settings

INTRODUCTION

Pediatric acute liver failure is a rare and serious disease. Though liver transplantation is considered as the established treatment option for patients who are unlikely to recover with medical management, however, with the advancement of medical care there has been an increase in spontaneous regeneration of liver, obviating the need for liver transplantation. We identified the etiologies, outcome and prognostic factors of acute liver failure and the validity of the existing liver transplantation criteria to predict the outcome of pediatric acute liver failure.

MATERIALS AND METHODS

This was a retrospective study done from January 2014 to December 2019 in a tertiary pediatric critical care unit in South India. All children aged between 1 month to 18 years admitted with acute liver failure were enrolled.

RESULTS

Of 125 children with acute liver failure, the main etiologies were infections (32%), indeterminate (23%), paracetamol toxicity (21%), metabolic (13%) and others (11%). Dengue was the most common infection (55%). The median pediatric logistic organ dysfunction score at admission was 12 (4-27). Of 125 patients, 63.2% (n = 79) had spontaneous regeneration which was higher in paracetamol induced (92.3%) compared to non-paracetamol induced acute liver failure (55.5%). Only two patients underwent liver transplantation and 35% died. Peak alanine transaminase and use of inotropes significantly predicted the outcome of disease. Of 38 children meeting King's College Hospital criteria for liver transplantation, 57.9% had spontaneous regeneration and 36.8% died. Of 74 children meeting INR > 4 criteria, 54% (n = 40) had spontaneous regeneration and 43.2% died. INR >4 criteria was more sensitive than King's College Hospital criteria for predicting the need for liver transplantation.

CONCLUSION

Pediatric acute liver failure is caused by varied etiologies and infections were the commonest cause. Despite having a seriously ill cohort of patients, medical management resulted in spontaneous regeneration in the majority of children with acute liver failure. The use of inotropes, advanced hepatic encephalopathy, and peak alanine transaminase were predictors of poor outcome in children with acute liver failure and these patients could be considered for liver transplantation as available. Therefore, we may need to develop better predictors of pediatric acute liver failure in resource limited settings.

Machine Learning Models to Predict Inhibition of the Bile Salt Export Pump

Cholestatic liver injury is frequently associated with drug inhibition of bile salt transporters, such as the bile salt export pump (BSEP). Reliable in silico models to predict BSEP inhibition directly from chemical structures would significantly reduce costs during drug discovery and could help avoid injury to patients. We report our development of classification and regression models for BSEP inhibition with substantially improved performance over previously published models. We assessed the performance effects of different methods of chemical featurization, data set partitioning, and class labeling and identified the methods producing models that generalized best to novel chemical entities.

Comorbidity Burden May Be Associated with Increased Mortality in Patients with Severe Acute Liver Injury Referred for Liver Transplantation

BACKGROUND Severe acute liver injury (S-ALI) can lead to acute liver and multisystem failure, with high mortality and need for liver transplantation (LT); however, the burden and impact of liver disease and comorbid conditions are unknown. MATERIAL AND METHODS We assessed liver disease and Charlson Comorbidity Index (CCI) in adults without cirrhosis evaluated for LT at our center for S-ALI between 2004 and 2017. The study endpoints were 30-day death or LT and 90-day mortality (with LT as a competing risk). RESULTS A total of 136 patients with S-ALI were included; 13% had underlying liver disease and a higher Model for End-stage Liver Disease score than those without liver disease. Sixty patients (41%) died or underwent LT within 30 days. They were older and more frequently female and had disease of autoimmune, viral, or indeterminate etiology. Transplant-free survival was associated with acetaminophen injury. The mean CCI was higher in patients with 30-day mortality or LT (1.5±2.4) vs. LT-free survivors (0.8±1.2), (P=0.03). Beyond severity of illness, CCI was associated with increased 90-day mortality (subhazard ratio 1.17, 95% confidence interval, 1.01-1.35) but not 30-day mortality or LT in the risk-adjusted analyses. CONCLUSIONS Comorbidity burden may be an important modifier of transplant-free survival in patients with S-ALI, but further studies are needed to validate these findings.

Acetaminophen Toxicity: A History of Serendipity and Unintended Consequences

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Acute Liver Failure Secondary to Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is the most common cause of acute liver failure (ALF) in Western countries. Without liver transplantation, the mortality rate for ALF approaches greater than 80%. Acetaminophen-related ALF may be associated with a rapid progression but fortunately has a high chance for spontaneous survival compared with idiosyncratic DILI-related ALF. Several prognostic scoring systems for severe DILI have been developed to aid clinicians in selecting patients who require urgent liver transplantation. Patients who undergo liver transplantation for ALF are at risk for early graft loss and death and should be closely followed.

Medicinal Thiols: Current Status and New Perspectives

The thiol (-SH) functional group is found in a number of drug compounds and confers a unique combination of useful properties. Thiol-containing drugs can reduce radicals and other toxic electrophiles, restore cellular thiol pools, and form stable complexes with heavy metals such as lead, arsenic, and copper. Thus, thiols can treat a variety of conditions by serving as radical scavengers, GSH prodrugs, or metal chelators. Many of the compounds discussed here have been in use for decades, yet continued exploration of their properties has yielded new understanding in recent years, which can be used to optimize their clinical application and provide insights into the development of new treatments. The purpose of this narrative review is to highlight the biochemistry of currently used thiol drugs within the context of developments reported in the last five years. More specifically, this review focuses on thiol drugs that represent the standard of care for their associated conditions, including N-acetylcysteine, 2,3-meso-dimercaptosuccinic acid, British anti-Lewisite, D-penicillamine, amifostine, and others. Reports of novel dosing regimens, delivery strategies, and clinical applications for these compounds were examined with an eye toward emerging approaches to address a wide range of medical conditions in the future.

Predictors of Acute Liver Failure in Patients With Acute Hepatitis A: An Analysis of the 2016-2018 San Diego County Hepatitis A Outbreak

Background

Between 2016 and 2018, San Diego County experienced a hepatitis A outbreak with a historically high mortality rate (3.4%) that highlighted the need for early recognition of those at risk of developing acute liver failure (ALF).

Methods

A retrospective case series of adult hospitalized patients with acute hepatitis A.

Results

One hundred six patients with hepatitis A were studied, of whom 11 (10.4%) developed ALF, of whom 7 (6.6%) died. A history of alcohol abuse, hyperbilirubinemia, hypoalbuminemia, hyponatremia, and anemia were associated with increased odds of developing ALF. Initial Maddrey’s and Model of End-Stage Liver Disease Sodium (MELD-Na) scores were also associated with the development of ALF. Multivariable analysis showed that a higher initial MELD-Na score (odds ratio [OR], 1.205; 95% confidence interval [CI], 1.018–1.427) and a lower initial serum albumin concentration (OR, 9.35; 95% CI, 1.15–76.9) were associated with increased odds of developing ALF. Combining serum albumin and MELD-Na (SAM; C-statistic, 0.8878; 95% CI, 0.756–0.988) yielded a model that was not better than either serum albumin (C-statistic, 0.852; 95% CI, 0.675–0.976) or MELD-Na (C-statistic, 0.891; 95% CI, 0.784–0.968; P = .841). Finally, positive blood cultures were more common among patients with ALF compared with those without ALF (63.6% vs 4.3%; P < .00001).

Conclusions

Hypoalbuminemia was associated with an increased risk of ALF in patients with acute hepatitis A. Positive blood cultures and septic shock as a cause of death were common among patients with ALF. Providers caring for patients with acute hepatitis A should monitor for early signs of sepsis and consider empiric antibiotics, especially in patients presenting with hypoalbuminemia.

Acetaminophen is Undetectable in Plasma From More Than Half of Patients Believed to Have Acute Liver Failure Due to Overdose

BACKGROUND & AIMS

Evaluation of patients with acute liver injury (ALI) or acute liver failure (ALF) often includes measurement of plasma levels of acetaminophen, to determine exposure and/or toxicity. However, once liver injury has developed, acetaminophen might be undetectable in plasma. We investigated the association between level of acetaminophen measured and outcomes of patients designated as having ALF or ALI due to acetaminophen toxicity.

METHODS

We performed a retrospective analysis of data from 434 subjects in the Acute Liver Failure Study Group who met criteria for ALF (coagulopathy and hepatic encephalopathy within 26 weeks of the first symptoms, without pre-existing liver disease) or ALI (severe liver injury with coagulopathy but no encephalopathy) due to acetaminophen toxicity from January 1, 2010 through December 31, 2014. We collected data on patient demographics, biochemical features, reported acetaminophen use, N-acetylcysteine therapy, liver transplant, and outcomes. Descriptive statistics were used to assess patient demographics, clinical characteristics, and outcomes whereas differences in continuous variables between patients with vs without acetaminophen detection on admission were analyzed using the Wilcoxon rank-sum test. The primary aim was to determine the proportion of patients with detectable plasma levels of acetaminophen.

RESULTS

Acetaminophen was undetectable in serum samples from 227 patients (52%). There were no significant differences between groups of patients with detectable vs undetectable levels in demographic features, alcohol use, median levels of alanine aspartate, or use of N-acetylcysteine (given to 94.7% of patients with detectable acetaminophen vs 95.9% of those with undetectable acetaminophen; P=.63). We observed a significant difference in median dose taken between patients with detectable (29,500 mg; interquartile range, 15,000 mg-50,007 mg) vs no detectable parent compound (14,950 mg; interquartile range, 3960 mg-25,000) (P=.003). A lower proportion of patients with detectable plasma levels of acetaminophen (72.3%) survived without a liver transplant than of patients with undetectable levels (86.3%) in univariate analysis (P=.0006), although this was not significant in multivariable analysis (P=.12). Although most patients had unintentional overdoses, a higher proportion of patients with suicidal overdoses (43%) had detectable levels of acetaminophen than patients with accidental overdoses (29.3%; P=.01).

CONCLUSION

More than half of patients who present at the hospital with acetaminophen-induced ALI or ALF have undetectable levels of acetaminophen. Clinicians should not exclude acetaminophen toxicity because of undetectable levels or withhold N-acetylcysteine for patients with ALI or ALF when acetaminophen toxicity is suspected.

Compound Ammonium Glycyrrhizin Protects Hepatocytes from Injury Induced by Lipopolysaccharide/Florfenicol through a Mitochondrial Pathway

Florfenicol (FFC), a widely used drug for chicken diseases, can aggravate lipopolysaccharide (LPS) damage to the liver. For this condition, natural or synthetic products displaying strong antioxidant capacity are expected to prevent LPS/FFC from inducing liver injury, so in our study, the compound ammonium glycyrrhizin (CAG) is used as the protective drug to decrease the injury to liver. The research aims to illustrate the underlying mechanism of combining LPS with FFC-induced liver injury and the protective role of CAG by using primary chicken hepatocytes as an in vitro model. The results show that LPS/FFC induced cell apoptosis and CAG protected hepatocytes from injury. The permeability of the cell membrane is elevated by LPS/FFC, leading to the efflux of enzymes (ALT, AST). Flow cytometry analysis indicates that LPS/FFC treatment increased the apoptosis rate significantly. Furthermore, with the up-regulation of apoptosis genes bax, cytochrome c and the down-regulation of bcl-2, caspase-3 and caspase-9 are activated at the gene level. LPS/FFC-induced mitochondrial damage is accompanied by a significant decrease in mitochondrial membrane potential (MMP) and severe mitochondrial damage. However, CAG improves the situation for the purpose of protecting the liver. In conclusion, it is speculated that LPS/FFC induces severe liver injury through apoptosis and the CAG protects hepatocytes from injury via the mitochondria-mediated apoptosis pathway.

Prognostic Models in Acute Liver Failure

There is a strong imperative to develop valid and accurate prognostic modeling for acute liver failure (ALF). Despite the numerous clinical models that have been proposed thus far and the use of some such models, that is, King's College Criteria and Model for End-Stage Liver Disease, in clinical practice to aid decision-making, there is a significant need for improvement for determining patients' clinical course, survival, and requirement for liver transplantation. Future prognostic models shall need a stronger statistical foundation and accountability for time and variability in the clinical course of ALF and be applied for pretransplant and posttransplant outcomes.

Atypical manifestations of hepatitis A virus infection

Acute hepatitis due to the hepatitis A virus usually has a short, benign and self-limited course, without causing chronic hepatitis. However, some cases have an atypical presentation, such as relapsing hepatitis, prolonged or persistent cholestasis, fulminant hepatic failure, or liver failure associated with autoimmune hepatitis. The typical clinical course of acute hepatitis A virus infection is spontaneous remission in 90% of the cases, but atypical cases have a prevalence that varies from less than 1 to 20%, depending on the manifestation (overall prevalence ∼7%). There is little information on the atypical clinical courses of hepatitis A virus infection and the lack of recognizing those presentations in clinical practice often results in carrying out numerous studies and treatments that not only are unnecessary, but can also be harmful. The aim of the present article was to describe 3 clinical cases of atypical hepatitis A infection and provide a literature review of such cases.

Living Donor Liver Transplantation for Wilson's Disease Associated with Fulminant Hepatic Failure: A Case Report

Patient: Female, 17

Final Diagnosis: Fulminant Wilson’s disease

Symptoms: General jaundice • malaise • abdominal pain

Medication: —

Clinical Procedure: ICU

Specialty: Transplantology

A Single Institution's Experience (1982–1999) with Plasma-Exchange Therapy in Patients with Fulminant Hepatic Failure

Fulminant hepatic failure is a rare, but often fatal complication of acute viral hepatitis. This condition, in absence of orthotopic liver transplantation (OLTx) surgery, is associated with a high mortality rate, despite the improvement of general intensive care.

Plasma-exchange (PEx) therapy has been long used to treat FHF, in particular by removing toxic substances and correcting the severe coagulopathy.

In this study we describe our experience with PEx treatment of FHF, beginning in 1982. Seventy patients affected with FHF due to various causes (HBV=40; cryptogenic/non-A, non-E=15; Amanita phalloides=8; other=7) were treated with PEx (altogether 348 sessions).

Overall survival rate, comprising patients undergoing OLTx, was 51%, a little higher than what we observed in patients (N=49) treated solely by PEx, i.e., 41%.

The best outcome predictor was FHF aetiology, owing to the good survival rate in patients with Amanita phalloides intoxication and the very poor prognosis of patients suffering from cryptogenic/non-A, non-E FHF. Moreover, the marked increase in prothrombin time and alpha-fetoprotein levels after 48 hours from admission was associated with a good prognosis, whereas the patient's age and coma grade were not clearly predictive of survival. Additionally, lymphocyte subpopulation, resulting in a CD4/CD8 ratio lower than 1.0 along with CD8 activation with HLA-DR strong expression, were associated with a high rate of mortality and morbidity.

Our data indicate that PEx therapy can improve survival in patients with sufficient residual capacity of liver regeneration. Moreover, the identification of certain prognostic factors may be useful for the rational planning of therapeutic strategy in FHF.

Protective effect of an L-type calcium channel blocker, amlodipine, on paracetamol-induced hepatotoxicity in rats

Paracetamol (P), one of the most popular and commonly used analgesic and antipyretic agents, causes hepatotoxicity in overdoses. Amlodipine (AML), an L-type calcium channel blocker, has been shown to have anti-inflammatory activity by reversing the effect of calcium in the inflammation pathogenesis. In this study, the hepatoprotective activity of AML on P-induced hepatotoxicity was evaluated. Thirty male albino Wistar rats were divided into five groups: (1) control, (2) 2 g/kg of P, (3) 2 g/kg of P + 5 mg/kg of AML, (4) 2 g/kg of P + 10 mg/kg of AML, and (5) 10 mg/kg of AML. Some liver enzymes, oxidative parameters, cytokine mRNA expressions, histopathology, and immunohistochemical studies were performed in liver and blood samples. The serum levels of alanine aminotransferase and aspartate aminotransferase and the mRNA expression of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta in the liver tissues were significantly increased in the group treated with P. The superoxide dismutase and glutathione parameters decreased and malondialdehyde levels increased in the livers of the rats treated with P. All these parameters were increased with both doses of the AML similar to the control group. A histopathological examination of the liver showed that AML administration ameliorated the P-induced inflammatory liver damage. In immunohistochemical staining, the expression of TNF-α in the cytoplasm of the hepatocytes was increased in the P group but not in other treatment groups when compared to the control. In conclusion, AML treatment showed significant protective effects against P-induced hepatotoxicity by increasing the activity of antioxidants and reducing inflammatory cytokines.

Acetaminophen (APAP) hepatotoxicity-Isn't it time for APAP to go away?

Acetaminophen (APAP) is the most commonly used drug for the treatment of pain and fever around the world. At the same time, APAP can cause dose-related hepatocellular necrosis, responsible for nearly 500 deaths annually in the United States (US) alone, as well as 100,000 calls to US Poison Control Centers, 50,000 emergency room visits and 10,000 hospitalisations per year. As an over-the-counter and prescription product (with opioids), APAP toxicity dwarfs all other prescription drugs as a cause of acute liver failure in the US and Europe, but it is not regulated in any significant way. In this review the ongoing controversy surrounding the proper role for this ubiquitous pain reliever: its history, pathogenesis, clinical challenges in recognition and management, and current regulatory status are highlighted. A new solution to a 50-year-old problem is proposed.

Functional Evaluation of a Bioartificial Liver Support System Using Immobilized Hepatocyte Spheroids in a Porcine Model of Acute Liver Failure

Bioartificial livers (BAL) may offer acute liver failure (ALF) patients an opportunity for cure without liver transplantation. We evaluated the efficacy of a spheroid-based BAL system, containing aggregates of porcine hepatocytes, in a porcine model of ALF. ALF pigs were divided into three groups. The control group consisted of treatment naïve pigs (n = 5), blank group consisted of pigs that were attached to the BAL system not containing hepatocytes for 12 hours (n = 5) and BAL group consisted of pigs that were attached to the BAL containing hepatocytes for 12 hours (n = 5). Increase in serum ammonia levels were significantly greater in the blank group (P < 0.01) and control group (P < 0.01), compared to the BAL group during the treatment period. Increase in ICP was significantly greater in the control group compared to the BAL group (P = 0.01). Survival was significantly prolonged in the BAL group compared to the blank group (P = 0.03). A BAL system with a bioreactor containing hepatocyte spheroids showed effective clearance of serum ammonia, preservation of renal function and delayed ICP increase in a porcine model of ALF.

Ammonium glycyrrhizin counteracts liver injury caused by lipopolysaccharide/amoxicillin-clavulanate potassium

We treated isolated chicken primary hepatocytes with lipopolysaccharide/amoxicillin clavulanate potassium (LPS/AC) to model liver injury and investigate its underlying mechanisms. We also used this model to assess the cytoprotective effects of compound ammonium glycyrrhizin (CAG) in vitro. LPS/AC-induced injury decreased cell viability and increased the activity of serum aspartate transaminase and alanine transaminase. Levels of superoxide dismutase, glutathione, and glutathione peroxidase were lower than control, while levels of the oxidative product malondialdehyde and reactive oxygen species were higher. Treatment with CAG for 24 h ameliorated these changes. Caspase-3 activity assays and flow cytometry revealed increased apoptosis in the model group. However, apoptosis decreased after CAG treatment, as confirmed by Hoechst 33342 staining. We also observed changes in mitochondrial ultrastructure. Real-time PCR and western blot analyses showed that CAG treatment downregulated LPS/AC-induced RNA expression of caspase-3, caspase-9, bax, cytochrome c, and fas, and upregulated the expression of bcl-2. Mitochondrial cytochrome c was released into the cytosol and the inner mitochondrial membrane potential (ΔΨm) was decreased. Our results highlight CAG as a potential therapeutic agent to counteract LPS/AC-induced liver injury.

Role of N-acetylcysteine treatment in non-acetaminophen-induced acute liver failure: A prospective study

BACKGROUND/AIMS

Acute liver failure (ALF) is a rare but severe medical emergency. To date, there is no established treatment for non-acetaminophen-induced acute liver failure (NAI-ALF) other than liver transplantation, and little is known about the use of N-acetylcysteine (NAC) in NAI-ALF. A randomized case control study was conducted with the aim to determine the effect of NAC on the mortality of NAI-ALF patients, as well as to evaluate the safety and efficacy of NAC use.

PATIENTS AND METHODS

A total of 80 patients diagnosed with NAI-ALF were included in the study. Forty patients received NAC infusion for 72 h whereas the control group received placebo. The variables evaluated were demographic characteristics, signs and symptoms, biochemical parameters, and clinical course during hospitalization.

RESULTS

The two groups (NAC and control) were comparable for various baseline characteristics (such as etiology of ALF, INR, alanine aminotransferase, creatinine, albumin, and grade of encephalopathy), except for age. Although majority of patients had undetermined etiology (32.5% in NAC group and 42.5% in control group), the second main cause was acute hepatitis E and drug or toxin-induced ALF. The mortality decreased to 28% with the use of NAC versus 53% in the control group (P = 0.023). The use of NAC was associated with shorter length of hospital stay in survived patients (P = 0.002). Moreover, the survival of patients was improved by NAC (P = 0.025). Also, drug-induced ALF showed improved outcome compared to other etiologies.

CONCLUSION

The findings of the study recommend the use of NAC along with conventional treatments in patients with NAI-ALF in non-transplant centers while awaiting referrals and conclude the use of NAC as safe.

Toxicant-Induced Hepatic Injury

The sudden failure of a previously healthy and functioning liver is a dramatic and devastating event. Acute liver failure is the common final pathway of a multitude of conditions and insults, all of which result in massive hepatic necrosis or loss of normal hepatic function. The ensuing multiorgan system failure frequently has a fatal outcome, with mortality rates in most series ranging from approximately 55% to 95% [1]. Acute liver failure (ALF, previously often referred to as fulminant hepatic failure (FHF)) knows no age boundaries, with many cases occurring in those younger than 30 years. Short of excellent intensive care unit (ICU) support and liver transplantation in selected cases, few viable treatment options are available. Over the past few decades, however, survival has been improved by anticipation, recognition, and early treatment of associated complications, as well as the application of prognostic criteria for early identification of patients requiring liver transplantation (along with improvement in the techniques and science of transplantation itself). The etiology of ALF varies from country to country and the incidence change over time. Paracetamol (acetaminophen) has now replaced viral hepatitis as the leading cause of ALF [2]. In a study from London including 310 patients with ALF in the period 1994–2004, 42% of the cases were caused by paracetamol [3], whereas this was only the cause in 2% of 267 patients in Spain from 1992 to 2000 [4]. However, less than 10% of all liver transplants are performed in patients with ALF [5, 6].

From hepatoprotection models to new therapeutic modalities for treating liver diseases: a personal perspective

A variety of rodent models of hepatoprotection have been developed in which tolerance to acetaminophen-induced hepatotoxicity occurs. Autoprotection/heteroprotection is a phenomenon where prior exposure to a mildly toxic dose of toxicant confers protection against a subsequently administered higher dose of the same toxicant (as in the case of autoprotection) or to a different toxicant (referred to as heteroprotection). Multiple mechanisms regulate this adaptive response, including hepatocellular proliferation, proteostasis, enhanced expression of cytoprotective genes, and altered tissue immune response. In this review, we will discuss recent findings that highlight the complexity of these adaptive mechanisms and we also outline the usefulness of these findings to devise therapeutic and/or diagnostic tools for acetaminophen-induced liver damage in patients.

Acute Liver Failure: Diagnosis and Management

Acute liver failure is life threatening liver injury with coagulopathy and hepatic encephalopathy within 26 weeks and generally, in the absence of preexisting liver disease. Fulminant liver failure occurs when hepatic encephalopathy occurs within 8 weeks of jaundice. The majority of patients with ALF are women with the median age of 38 years. In the United States, drug induced liver injury including acetaminophen causes the majority of ALF cases. The etiology of ALF should be determined, if possible, because many causes have a specific treatment. The mainstay for ALF is supportive care and liver transplantation, if necessary. There are multiple prognostic criteria available. Prognosis can be poor and patients should be referred to a liver transplantation center as soon as possible.

Liver transplant center variability in accepting organ offers and its impact on patient survival

BACKGROUND & AIMS

Despite an allocation system designed to give deceased-donor livers to the sickest patients, many transplantable livers are declined by U.S. transplant centers. It is unknown whether centers vary in their propensities to decline organs for the highest priority patients, and how these decisions directly impact patient outcomes.

METHODS

We analyzed Organ Procurement and Transplantation Network (OPTN) data from 5/1/07-6/17/13, and included all adult liver-alone waitlist candidates offered an organ that was ultimately transplanted. We evaluated acceptance rates of liver offers for the highest ranked patients and their subsequent waitlist mortality.

RESULTS

Of the 23,740 unique organ offers, 8882 (37.4%) were accepted for the first-ranked patient. Despite adjusting for organ quality and recipient severity of illness, transplant centers within and across geographic regions varied strikingly (p<0.001) in the percentage of organ offers they accepted for the highest priority patients. Among all patients ranked first on waitlists, the adjusted center-specific organ acceptance rates ranged from 15.7% to 58.1%. In multivariable models, there was a 27% increased odds of waitlist mortality for every 5% absolute decrease in a center's adjusted organ offer acceptance rate (adjusted OR: 1.27, 95% CI: 1.20-1.32). However, the absolute difference in median 5-year adjusted graft survival was 4% between livers accepted for the first-ranked patient, compared to those declined and transplanted at a lower position.

CONCLUSION

There is marked variability in center practices regarding accepting livers allocated to the highest priority patients. Center-level decisions to decline organs substantially increased patients' odds of dying on the waitlist without a transplant.

Coagulopathy and transfusion therapy in pediatric liver transplantation

Bleeding and coagulopathy are critical issues complicating pediatric liver transplantation and contributing to morbidity and mortality in the cirrhotic child. The complexity of coagulopathy in the pediatric patient is illustrated by the interaction between three basic models. The first model, "developmental hemostasis", demonstrates how a different balance between pro- and anticoagulation factors leads to a normal hemostatic capacity in the pediatric patient at various ages. The second, the "cell based model of coagulation", takes into account the interaction between plasma proteins and cells. In the last, the concept of "rebalanced coagulation" highlights how the reduction of both pro- and anticoagulation factors leads to a normal, although unstable, coagulation profile. This new concept has led to the development of novel techniques used to analyze the coagulation capacity of whole blood for all patients. For example, viscoelastic methodologies are increasingly used on adult patients to test hemostatic capacity and to guide transfusion protocols. However, results are often confounding or have limited impact on morbidity and mortality. Moreover, data from pediatric patients remain inadequate. In addition, several interventions have been proposed to limit blood loss during transplantation, including the use of antifibrinolytic drugs and surgical techniques, such as the piggyback and lowering the central venous pressure during the hepatic dissection phase. The rationale for the use of these interventions is quite solid and has led to their incorporation into clinical practice; yet few of them have been rigorously tested in adults, let alone in children. Finally, the postoperative period in pediatric cohorts of patients has been characterized by an enhanced risk of hepatic vessel thrombosis. Thrombosis in fact remains the primary cause of early graft failure and re-transplantation within the first 30 d following surgery, and it occurs despite prolongation of standard coagulation assays. Data, however, are currently lacking regarding the use of anti-aggregation/anticoagulation therapies and how to best monitor for thrombosis in the early postoperative period in pediatric patients. Therefore, further studies are necessary to elucidate the interaction between the development of the coagulation system and cirrhosis in children. Moreover, strategies to optimize blood transfusion and anticoagulation must be tested specifically in pediatric patients. In conclusion, data from the adult world can be translated with difficulty into the pediatric field as indication for transplantation, baseline pathologies and levels of pro- and anticoagulation factors are not comparable between the two populations.

Hepatic Failure

The progression of liver disease can cause several physiologic derangements that may precipitate hepatic failure and require admission to an intensive care unit. The underlying pathology may be acute, acute-on chronic, or chronic in nature. Liver failure may manifest with a variety of clinical signs and symptoms that need prompt attention. The compromised synthetic and metabolic activity of the failing liver affects all organ systems, from neurologic to integumentary. Supportive care and specific therapies should be instituted in order to improve outcome and minimize time of recovery.

In this chapter we will discuss the definition, clinical manifestations, workup, and management of acute and chronic liver failure and the general principles of treatment of these patients. Management of liver failure secondary to certain common etiologies will also be presented. Finally, liver transplantation and alternative therapies will also be discussed.

A Rare Case of Transfusion Transmission of Hepatitis A Virus to Two Patients with Haematological Disease

BACKGROUND

This paper describes the transmission of hepatitis A virus (HAV) to two blood recipients from a healthy donor that later presented to the blood bank with jaundice.

METHODS

The RNA of HAV was detected by qualitative nested reverse transcription polymerase chain reaction (nested RT-PCR) and quantified by real-time RT-PCR. HAV RNA samples were genotyped by direct sequencing of PCR products. A sequence from a fragment of 168 bp from the VP1/2A HAV region was used to construct a phylogenetic tree.

CASE REPORT

A 31-year-old male donor accepted for donation of a whole blood unit returned to the blood bank with clinical jaundice 20 days after donation. His serological and NAT tests were negative for HBV and HCV. Serological tests for HAV IgM and IgG were negative on donation sample but positive on follow-up sample, confirming donor's HAV acute infection. Both recipients of red blood cells (R1) and platelet concentrate (R2) from the same implicated donation were HAV IgM-negative and IgG-positive. Qualitative PCR was positive on samples from all three individuals and phylogenetic analysis of viruses proved HAV transmission to the two recipients of blood products. HAV viral load on donor follow-up sample and the platelet recipient was 1.3 and 1.5 × 10(3) IU/ml, respectively. The RBC recipient, also infected by HCV, was undergoing bone marrow transplantation and died from fulminant hepatitis, 26 days after the implicated HAV transfusion.

CONCLUSION

The blood donor, a garbage collector, spontaneously returned to the blood bank when developing jaundice. This highlights the importance of donor education to immediately report to blood banks of any signs and symptoms related to infectious disease developed after blood donation. The fact that one immunocompromised patient with HCV infection died from fulminant hepatitis after receiving a HAV-contaminated platelet transfusion underpins the importance of a HAV vaccination program for these group of patients.

N-acetylcysteine amide, a promising antidote for acetaminophen toxicity

Acetaminophen (N-acetyl-p-aminophenol, APAP) is one of the most widely used over the counter antipyretic and analgesic medications. It is safe at therapeutic doses, but its overdose can result in severe hepatotoxicity, a leading cause of drug-induced acute liver failure in the USA. Depletion of glutathione (GSH) is one of the initiating steps in APAP-induced hepatotoxicity; therefore, one strategy for restricting organ damage is to restore GSH levels by using GSH prodrugs. N-acetylcysteine (NAC), a GSH precursor, is the only currently approved antidote for an acetaminophen overdose. Unfortunately, fairly high doses and longer treatment times are required due to its poor bioavailability. In addition, oral and I.V. administration of NAC in a hospital setting are laborious and costly. Therefore, we studied the protective effects of N-acetylcysteine amide (NACA), a novel antioxidant with higher bioavailability, and compared it with NAC in APAP-induced hepatotoxicity in C57BL/6 mice. Our results showed that NACA is better than NAC at a low dose (106mg/kg) in preventing oxidative stress and protecting against APAP-induced damage. NACA significantly increased GSH levels and the GSH/GSSG ratio in the liver to 66.5% and 60.5% of the control, respectively; and it reduced the level of ALT by 30%. However, at the dose used, NAC was not effective in combating the oxidative stress induced by APAP. Thus, NACA appears to be better than NAC in reducing the oxidative stress induced by APAP. It would be of great value in the health care field to develop drugs like NACA as more effective and safer options for the prevention and therapeutic intervention in APAP-induced toxicity.

Mesenchymal stromal cell therapy in liver disease: opportunities and lessons to be learnt?

End-stage liver disease is responsible for 30,000 deaths per year in the United States alone, and it is continuing to increase every year. With liver transplantation the only curative treatment currently available, new therapies are in great demand. Mesenchymal stem cells (MSC) offer an opportunity to both treat liver inflammatory damage, as well as reverse some of the changes that occur following chronic liver injury. With the ability to regulate both the innate and adaptive immune system, as well as both inhibit and promote apoptosis of effector inflammatory cells, there are numerous therapeutic opportunities for MSC in acute and chronic liver disease. This article critically appraises the potential therapeutic roles of MSC in liver disease, as well as the barriers to their adoption into clinical practice.

What Are the Potential Sites of Protein Arylation by N-Acetyl-p-benzoquinone Imine (NAPQI)?

Acetaminophen (paracetamol, APAP) is a safe and widely used analgesic medication when taken at therapeutic doses. However, APAP can cause potentially fatal hepatotoxicity when taken in overdose or in patients with metabolic irregularities. The production of the electrophilic and putatively toxic compound N-acetyl-p-benzoquinone imine (NAPQI), which cannot be efficiently detoxicated at high doses, is implicated in APAP toxicity. Numerous studies have identified that excess NAPQI can form covalent linkages to the thiol side chains of cysteine residues in proteins; however, the reactivity of NAPQI toward other amino acid side chains is largely unexplored. Here, we report a survey of the reactivity of NAPQI toward 11 N-acetyl amino acid methyl esters and four peptides. (1)H NMR analysis reveals that NAPQI forms covalent bonds to the side-chain functional groups of cysteine, methionine, tyrosine, and tryptophan residues. Analogous reaction products were observed when NAPQI was reacted with synthetic model peptides GAIL-X-GAILR for X = Cys, Met, Tyr, and Trp. Tandem mass spectrometry peptide sequencing showed that the NAPQI modification sites are located on the "X" residue in each case. However, when APAP and the GAIL-X-GAILR peptide were incubated with rat liver microsomes that contain many metabolic enzymes, NAPQI formed by oxidative metabolism reacted with GAIL-C-GAILR exclusively. For the peptides where X = Met, Tyr, and Trp, competing reactions between NAPQI and alternative nucleophiles precluded arylation of the target peptide by NAPQI. Although Cys residues are favorably targeted under these conditions, these data suggest that NAPQI can, in principle, also damage proteins at Met, Tyr, and Trp residues.

Importance of the poor prognosis of severe and fulminant hepatitis in the elderly in an era of a highly aging society: Analysis in a Japanese center

AIM

Older age has been widely believed to be associated with a poor prognosis of acute liver failure. We aimed to evaluate the impact of older age on outcomes of Japanese patients with severe and fulminant hepatitis in an era of a highly aging society.

METHODS

We investigated 105 consecutive adult patients with fulminant hepatitis (FH) or severe hepatitis (SH) admitted to our liver unit between 2000 and 2013, consisting of 14 elderly patients (≥65 years) and 91 younger ones (<65 years).

RESULTS

In elderly patients, the proportion of women was greater (P < 0.001), the levels of aspartate aminotransferase and lactate dehydrogenase on admission were lower (P = 0.011 and P = 0.010, respectively), and the survival rate without liver transplantation was lower (P = 0.024) than younger ones. Two of seven SH and all seven FH elderly patients died, whereas all 45 SH and 16 of 46 FH younger patients recovered. Seventy-one percent of elderly patients had underlying diseases with medications, and 57% had additional complications after the start of treatment for acute liver failure. Patients aged 70 years or more showed even poorer prognoses than younger ones and those aged 65-69 years (P = 0.0052 and P = 0.036, respectively).

CONCLUSION

Older age was associated with a poor prognosis of patients with SH and FH. One of the reasons other than complications and loss of organ reserve by aging would be that elderly patients consulted us at a more advanced stage of illness than younger ones.

Population-representative incidence of drug-induced acute liver failure based on an analysis of an integrated health care system

BACKGROUND & AIMS

Medications are a major cause of acute liver failure (ALF) in the United States, but no population-based studies have evaluated the incidence of ALF from drug-induced liver injury. We aimed to determine the incidence and outcomes of drug-induced ALF in an integrated health care system that approximates a population-based cohort.

METHODS

We performed a retrospective cohort study using data from the Kaiser Permanente Northern California (KPNC) health care system between January 1, 2004, and December 31, 2010. We included all KPNC members age 18 years and older with 6 months or more of membership and hospitalization for potential ALF. The primary outcome was drug-induced ALF (defined as coagulopathy and hepatic encephalopathy without underlying chronic liver disease), determined by hepatologists who reviewed medical records of all KPNC members with inpatient diagnostic and laboratory criteria suggesting potential ALF.

RESULTS

Among 5,484,224 KPNC members between 2004 and 2010, 669 had inpatient diagnostic and laboratory criteria indicating potential ALF. After medical record review, 62 (9.3%) were categorized as having definite or possible ALF, and 32 (51.6%) had a drug-induced etiology (27 definite, 5 possible). Acetaminophen was implicated in 18 events (56.3%), dietary/herbal supplements in 6 events (18.8%), antimicrobials in 2 events (6.3%), and miscellaneous medications in 6 events (18.8%). One patient with acetaminophen-induced ALF died (5.6%; 0.06 events/1,000,000 person-years) compared with 3 patients with non-acetaminophen-induced ALF (21.4%; 0.18/1,000,000 person-years). Overall, 6 patients (18.8%) underwent liver transplantation, and 22 patients (68.8%) were discharged without transplantation. The incidence rates of any definite drug-induced ALF and acetaminophen-induced ALF were 1.61 events/1,000,000 person-years (95% confidence interval, 1.06-2.35) and 1.02 events/1,000,000 person-years (95% confidence interval, 0.59-1.63), respectively.

CONCLUSIONS

Drug-induced ALF is uncommon, but over-the-counter products and dietary/herbal supplements are its most common causes.

Hepatotoxicity induced by acute and chronic paracetamol overdose in adults. Where do we stand?

Paracetamol (Acetaminophen) poisoning data can reveal the potential deficiencies of paracetamol poisoning management guidelines. We conducted a retrospective cohort study of patients >18years who were attended in the emergency department (ED) of a Spanish tertiary hospital, from 2005 to 2010 for suspected paracetamol overdose and who had measurable paracetamol concentrations. 208 patients suspected of paracetamol poisoning were identified. The annual incidence in the ED increased from 2.0 (95%-CI: 0.2-7.2) cases per 10,000 patients in 2005 to 3.4 (95%-CI: 1.1-8.8) in 2010. Only 7 of 98 patients (7.14%) with acute poisoning at toxic doses showed hepatotoxicity signs, 4 (57.1%) of whom presented acute liver failure (ALF) criteria, while 8 of 10 patients (80%) with chronic paracetamol poisoning at toxic doses presented hepatotoxicity and 3 (37.5%) with ALF criteria. The time required to find medical care was 9.0h for acute poisoning and 49.6h for chronic poisoning (p<0.001). We conclude that the incidence of suspected cases of paracetamol poisoning at our hospital is increasing. The majority of toxicity cases, including ALF, associated with the ingestion of paracetamol were due to chronic poisoning. This finding constitutes an important warning regarding paracetamol chronic poisoning, and clinicians should have a higher index of clinical suspicion for this entity.