Acute liver failure in Scotland: changes in aetiology and outcomes over time (the Scottish Look-Back Study)

No Significant Beneficial Effects of Intravenous N-Acetylcysteine on Patient Outcome in Non-Paracetamol Acute Liver Failure: A Meta-Analysis of Randomized Controlled Trials

Acute liver failure is a life-threatening organ dysfunction with systemic organ involvement and is associated with significant mortality and morbidity unless specific management is undertaken. This meta-analysis aimed to assess the effects of intravenous N-acetylcysteine (NAC) on mortality and the length of hospital stay in patients with non-acetaminophen acute liver failure. Two hundred sixty-six studies from four databases were screened, and four randomized control trials were included in the final analysis. Our results could not demonstrate increased overall survival (OR 0.70, 95% CI [0.34, 1.44], p = 0.33) or transplant-free survival (OR 0.90, 95% CI [0.25, 3.28], p = 0.87) in patients treated with intravenous NAC. We observed an increased overall survival in adult patients treated with NAC (OR 0.59, 95% CI [0.35, 0.99], p = 0.05) compared to pediatric patients, but whether this is attributed to the age group or higher intravenous dose administered remains unclear. We did not observe a decreased length of stay in NAC-treated patients (OR -5.70, 95% CI [-12.44, 1.05], p = 0.10). In conclusion, our meta-analysis could not demonstrate any significant benefits on overall and transplant-free patient survival in non-acetaminophen ALF. Future research should also focus on specific etiologies of ALF that may benefit most from the use of NAC.

Role of Gut Microecology in the Pathogenesis of Drug-Induced Liver Injury and Emerging Therapeutic Strategies

Drug-induced liver injury (DILI) is a common clinical pharmacogenic disease. In the United States and Europe, DILI is the most common cause of acute liver failure. Drugs can cause hepatic damage either directly through inherent hepatotoxic properties or indirectly by inducing oxidative stress, immune responses, and inflammatory processes. These pathways can culminate in hepatocyte necrosis. The role of the gut microecology in human health and diseases is well recognized. Recent studies have revealed that the imbalance in the gut microecology is closely related to the occurrence and development of DILI. The gut microecology plays an important role in liver injury caused by different drugs. Recent research has revealed significant changes in the composition, relative abundance, and distribution of gut microbiota in both patients and animal models with DILI. Imbalance in the gut microecology causes intestinal barrier destruction and microorganism translocation; the alteration in microbial metabolites may initiate or aggravate DILI, and regulation and control of intestinal microbiota can effectively mitigate drug-induced liver injury. In this paper, we provide an overview on the present knowledge of the mechanisms by which DILI occurs, the common drugs that cause DILI, the gut microbiota and gut barrier composition, and the effects of the gut microbiota and gut barrier on DILI, emphasizing the contribution of the gut microecology to DILI.

Viral hepatitis-induced acute liver failure

Viral hepatitis-induced acute liver failure (ALF) is a preventable cause for liver-related mortality worldwide. Viruses are the most common cause for ALF in developing nations in contrast to the west, where acetaminophen is largely responsible. Viruses may be hepatotropic or affect the liver secondary to a systemic infection. In tropical countries, infections such as leptospirosis, scrub typhus and malaria can mimic the symptoms of ALF. Differentiating these ALF mimics is crucial because they require etiology-specific therapy. Treatment of viral hepatitis-induced ALF is two-pronged and directed towards providing supportive care to prevent organ failures and antiviral drugs for some viruses. Liver transplantation (LT) is an effective modality for patients deteriorating despite adequate supportive care. Early referral and correct identification of patients who require a transplant are important. Liver support devices and plasma exchange have evolved into "bridging modalities" for LT. Preventive strategies such as hand hygiene, use of clean and potable water and inclusion of vaccines against viral hepatitis in the national program are simple yet very effective methods focusing on the preventive aspect of this disease.

Lycium barbarum L. Balanced intestinal flora with YAP1/FXR activation in drug-induced liver injury

Drug-induced liver injury (DILI) is a common and severe adverse drug reaction that can result in acute liver failure. Previously, we have shown that Lycium barbarum L. (wolfberry) ameliorated liver damage in acetaminophen (APAP)-induced DILI. Nevertheless, the mechanism needs further clarification. Herein, we utilized APAP-induced DILI mice to investigate how wolfberry impacts the gut-liver axis to mitigate liver damage. We showed that the abundance of Akkermansia muciniphila (A. muciniphila) was decreased, and intestinal microbiota was disrupted, while the expression levels of YAP1 and FXR-mediated CYP7A1 were reduced in the liver of DILI mice. Furthermore, wolfberry increased the abundance of A. muciniphila and the number of goblet cells in the intestines, while decreasing AST, ALT, and total bile acids (TBA) levels in the serum. Interestingly, A. muciniphila promoted YAP1 and FXR expression in hepatocytes, leading to the inhibition of CYP7A1 expression and a decrease in TBA content. Notably, wolfberry did not exert the beneficial effects mentioned above after the removal of intestinal bacteria by antibiotics (ATB)-containing water. Additionally, Yap1 knockout downregulated FXR expression and enhanced CYP7A1 expression in the liver of hepatocyte-specific Yap1 knockout mice. Therefore, wolfberry stimulated YAP1/FXR activation and reduced CYP7A1 expression by promoting the balance of intestinal microbiota, thereby suppressing the overproduction of bile acids.

Acetaminophen-induced liver injury at therapeutic doses in a young adult: a case report

Acetaminophen causes volume-dependent hepatotoxicity; however, hepatotoxicity may also occur with acetaminophen administered at normal doses. We encountered a case of allergic liver damage in a 17-year-old girl receiving acetaminophen at a regular dose. The patient was diagnosed using the Roussel Uclaf Causality Assessment Method (RUCAM) and the diagnostic scale of the Digestive Disease Week Japan 2004 workshop. She tested positive for acetaminophen on a drug-induced lymphocyte stimulation test, and liver biopsy results confirmed the diagnosis of acetaminophen-induced liver injury. Despite administering acetaminophen at normal doses, hepatotoxicity may occur, which warrants further exploration.

Indeterminate etiology of acute liver failure in North America: Less common, still grave prognosis

BACKGROUND

The etiology of acute liver failure (ALF) remains one of the most important factors in determining prognosis and predicting outcomes. In a significant proportion of ALF cases, however, the etiology remains unknown and is categorized as indeterminate ALF (IND-ALF). In this study, we summarize findings from patients with IND-ALF from 32 transplant centers across the United States, and we compare laboratory, prognostic, and outcome data for patients with IND-ALF.

METHODS

Between 1998 and 2019, 3364 adult patients with ALF or acute liver injury (ALI) from 32 liver transplant centers were enrolled in the ALFSG registry. The primary clinical outcome of interest was 21-day transplant-free survival (TFS).

RESULTS

Of the 3364 patients enrolled in the ALFSG registry, 3.4 % (n = 114) were adjudicated as true indeterminate. On multivariate analysis, patients with a lower bilirubin, lower INR, lack of use of mechanical ventilation and no clinical features of coma at baseline had a higher odds ratio of transplant free survival. The number of deaths were similar between patients with true-IND ALF versus patients with indeterminable ALF (29.8% vs. 27.2%), with almost half of the patients requiring liver transplant (42.1% vs. 45.7%).

CONCLUSION

We illustrate the poor prognoses that true-IND-ALF and indeterminable ALF carry and the need for emergency liver transplantation in most cases.

Clinical determinants of hospital mortality in liver failure: a comprehensive analysis of 62,717 patients

BACKGROUND

Liver failure (LF) is characterised by a loss of the synthetic and metabolic liver function and is associated with a high mortality. Large-scale data on recent developments and hospital mortality of LF in Germany are missing. A systematic analysis and careful interpretation of these datasets could help to optimise outcomes of LF.

METHODS

We used standardised hospital discharge data of the Federal Statistical Office to evaluate current trends, hospital mortality and factors associated with an unfavourable course of LF in Germany between 2010 and 2019.

RESULTS

A total of 62,717 hospitalised LF cases were identified. Annual LF frequency decreased from 6716 (2010) to 5855 (2019) cases and was higher among males (60.51%). Hospital mortality was 38.08% and significantly declined over the observation period. Mortality significantly correlated with patients' age and was highest among individuals with (sub)acute LF (47.5%). Multivariate regression analyses revealed pulmonary (ORARDS: 2.76, ORmechanical ventilation: 6.46) and renal complications (ORacute kidney failure: 2.04, ORhepatorenal syndrome: 2.92) and sepsis (OR: 1.92) as factors for increased mortality. Liver transplantation reduced mortality in patients with (sub)acute LF. Hospital mortality significantly decreased with the annual LF case volume and ranged from 47.46% to 29.87% in low- or high-case-volume hospitals, respectively.

CONCLUSIONS

Although incidence rates and hospital mortality of LF in Germany have constantly decreased, hospital mortality has remained at a very high level. We identified a number of variables associated with increased mortality that could help to improve framework conditions for the treatment of LF in the future.

A gene expression profile-based approach to screen the occurrence and predisposed host characteristics of drug-induced liver injury: a case study of Psoralea corylifolia Linn

Drug-induced liver injury (DILI) is one of the most common causes of a drug being withdrawn, and identifying the culprit drugs and the host factors at risk of causing DILI has become a current challenge. Recent studies have found that immune status plays a considerable role in the development of DILI. In this study, DILI-related differentially expressed genes mediated by immunoinflammatory cytokines were obtained from the Gene Expression Omnibus (GEO) database to predict the occurrence of DILI (named the DILI predictive gene set, DILI_PGS), and the predictability of the DILI_PGS was verified using the Connectivity Map (CMap) and LiverTox platforms. The results obtained DILI_PGS from the GEO database could predict 81.25% of liver injury drugs. In addition, the Coexpedia platform was used to predict the DILI_PGS-related characteristics of common host diseases and found that the DILI_PGS mainly involved immune-related diseases and tumor-related diseases. Then, animal models of immune stress (IS) and immunosuppressive (IP) were selected to simulate the immune status of the above diseases. Meanwhile, psoralen, a main component derived from Psoralea corylifolia Linn. with definite hepatotoxicity, was selected as an experimental drug with highly similar molecular fingerprints to three idiosyncratic hepatotoxic drugs (nefazodone, trovafloxacin, and nimesulide) from the same DILI_PGS dataset. The animal experiment results found a single administration of psoralen could significantly induce liver injury in IS mice, while there was no obvious liver function change in IP mice by repeatedly administering the same dose of psoralen, and the potential mechanism of psoralen-induced liver injury in IS mice may be related to regulating the expression of the TNF-related pathway. In conclusion, this study constructed the DILI_PGS with high accuracy to predict the occurrence of DILI and preliminarily identified the characteristics of host factors inducing DILI.

Liver Transplantation for Acute Liver Failure- Indication, Prioritization, Timing, and Referral

Acute liver failure (ALF) is a major success story in gastroenterology, with improvements in critical care and liver transplant resulting in significant improvements in patient outcomes in the current era compared to the dismal survival rates in the pretransplant era. However, the ever-increasing list of transplant candidates and limited organ pool makes judicious patient selection and organ use mandatory to achieve good patient outcomes and prevent organ wastage. Several scoring systems exist to facilitate the identification of patients who need a liver transplant and would therefore need an early referral to a specialized liver unit. The timing of the liver transplant is also crucial as transplanting a patient too early would lead to those who would recover spontaneously receiving an organ (wastage), and a late decision might result in the patient becoming unfit for transplant (delisted) or have an advanced disease which would result in poor post-transplant outcomes. The current article reviews the indications and contraindications of liver transplant in ALF patients, the various prognostic scoring systems, etiology-specific outcomes, prioritization and timing of referral.

Protective Effect of Water-Soluble Acacetin Prodrug on APAP-Induced Acute Liver Injury Is Associated with Upregulation of PPARγ and Alleviation of ER Stress

A water-soluble acacetin prodrug has been synthesized and reported by our group previously. Acetaminophen (APAP) overdose is a leading cause of acute liver injury. We found that subcutaneous injection of acacetin prodrug (5, 10, 20 mg/kg) decreased serum ALT, AST, and ALP, corrected the abnormal MDA and GSH in liver, and improved intrahepatic hemorrhage and destruction of liver structures in APAP (300 mg/kg)-treated mice. Molecular mechanism analysis revealed that the expressions of endoplasmic reticulum (ER) stress markers ATF6, CHOP, and p-PERK, apoptosis-related protein BAX, and cleaved caspase 3 were decreased by acacetin in a dose-dependent manner in vivo and in vitro. Moreover, via the acacetin-upregulated peroxisome-proliferator-activated receptor gamma (PPARγ) of HepG2 cells and liver, the suppressive effect of acacetin on ER stress and apoptosis was abolished by PPARγ inhibitor (GW9662) or PPARγ-siRNA. Molecular docking revealed that acacetin can bind to three active pockets of PPARγ, mainly by hydrogen bond. Our results provide novel evidence that acacetin prodrug exhibits significant protective effect against APAP-induced liver injury by targeting PPARγ, thereby suppressing ER stress and hepatocyte apoptosis. Acacetin prodrug is likely a promising new drug candidate for treating patients with acute liver injury induced by APAP.

[Drug toxic hepatopathy - an underestimated danger]

Drug-induced toxic hepatopathies and drug-induced liver injury, DILI, are characterized by a variety of clinical manifestations and therefore represent a significant diagnostic challenge. This article shows how DILI is diagnosed and what therapy options exist. Current special cases of DILI genesis are also discussed (DOACs, IBD drugs, tyrosine kinase inhibitors). These newer substances and corresponding hepatotoxic effects are not yet fully understood. The internationally recognized and online available RUCAM score (Roussel Uclaf Causality Assessment Method) helps to assess the probability of drug-related toxic liver damage.

Etiology of viral induced acute liver failure and defensins as potential therapeutic agents in ALF treatment

Acute liver failure (ALF) is a rare and severe disease, which, despite continuous advances in medicine, is still characterized by high mortality (65-85%). Very often, a liver transplant is the only effective treatment for ALF. Despite the implementation of prophylactic vaccinations in the world, the viral background of ALF is still a problem and leads to many deaths. Depending on the cause of ALF, it is sometimes possible to reverse this condition with appropriate therapies, which is why the search for effective antiviral agents seems to be a very desirable direction of research. Defensins, which are our natural antimicrobial peptides, have a very high potential to be used as therapeutic agents for infectious liver diseases. Previous studies on the expression of human defensins have shown that increased expression of human α and β-defensins in HCV and HBV infections is associated with a better response to treatment. Unfortunately, conducting clinical trials for ALF is very difficult due to the severity of the disease and the low incidence, therefore animal models are important for the development of new therapeutic strategies. One of the best animal models that has real reference to research on acute liver failure (ALF) is rabbit hemorrhagic disease in rabbits caused by the Lagovirus europaeus virus. So far, there have been no studies on the potential of defensins in rabbits infected with Lagovirus europaeus virus.

Evaluation of transcranial Doppler use in patients with acute liver failure listed for emergency liver transplantation

PURPOSE

Acute liver failure (ALF) is characterized by hepatic encephalopathy (HE) often due to intracranial hypertension (ICH). The risk/benefit-balance of intraparenchymal pressure catheter monitoring is controversial during ALF.

AIMS

Perform an evaluation of transcranial Doppler (TCD) use in patients with ALF listed for emergency liver transplantation.

MATERIAL AND METHODS

Single center retrospective cohort study including all patients registered on high emergency LT list between 2012 and 2018. All TCD measurements performed during ICU stay after listing and after LT (when performed) were recorded. TCD was considered abnormal when pulsatility index (PI) was >1.2.

RESULTS

Among 106 patients with ALF, forty-seven (44%) had a TCD while on list. They had more severe liver and extrahepatic organ failure. When performed, TCD was abnormal in 51% of patients. These patients more frequently developed ICH events (45% vs. 13%, p = .02) and more frequently required increase in sedative drugs and vasopressors. While 22% of patients with normal TCD spontaneously survived, all of those with abnormal TCD died or were transplanted (p = .02). All transplanted patients who had abnormal exams normalized their TCD within 2 (1-2) days after LT.

CONCLUSION

TCD may be a useful non-invasive tool for ICH detection and management, then guide sedation withdrawal.

Prognostic Scores in Acute Liver Failure Due to Viral Hepatitis

Viral infections are among the major causes of acute liver failure (ALF) worldwide. While the role of agents such as hepatitis A, B, C, D and E viruses in precipitating ALF are well known, improvements in serological assays have led to the detection of viral agents such as Epstein Barr virus, cytomegalovirus etc. as atypical causes of ALF. Despite the plethora of literature available on viral hepatitis and ALF, there is very limited large-scale epidemiologic data on the prevalence, risk factors of progression and outcomes in ALF of viral causes. This is important as viral infections remain the leading cause of ALF in the East and in developing countries, while the impact of viral ALF in the West has largely been ameliorated by effective vaccination and sanitization programs. This review focuses specifically on the available prognostic scores that aid in the management of ALF of viral etiologies while also briefly reviewing the current literature on newer viral agents known to cause ALF, risk factors of progression, outcomes and how management algorithms can be developed by incorporation of prognostic scoring systems for referral and transplant listing.

Characteristics and outcomes of acute hepatitis of unknown etiology in Egypt: first report of adult adenovirus-associated hepatitis

Purpose

Several outbreaks of acute hepatitis of unknown etiology (AHUE) in children were reported in 2022 in many countries, with adenovirus identified as the etiological agent in most of them. We aimed to evaluate the characteristics and outcomes of AHUE cases in Egypt.

Methodology

Hospitalized patients with acute hepatitis were included in the study. Drug-induced, alcoholic hepatitis, autoimmune hepatitis, and Wilson’s disease were identified either by medical history or by routine laboratory diagnosis. Molecular and serological approaches were used to investigate common viral causes of hepatitis, such as hepatitis A–E viruses, cytomegalovirus, Epstein–Barr virus, herpes simplex viruses (HSV1/2), adenovirus, parvovirus B19, and coxsackie virus.

Results

A total of 42 patients were recruited and divided into two groups: 24 cases of unknown hepatitis after excluding the common causes and 18 cases of known hepatitis. About two-thirds of the patients were male (61.9%), and the mean age was 34.55 ± 16.27 years. Jaundice, dark urine, abdominal pain and diarrhea were recorded at a higher incidence in group 1, while jaundice and fever were frequent in group 2. Fulminant hepatitis occurred in 28.6% of the cases, but the two groups did not differ significantly in terms of patient outcome, duration of hospitalization, ascites, and development of fulminant hepatitis. Adenovirus was detected in five cases (20.8%) in group 1, and one case co-infecting with hepatitis E virus in group 2. Herpes simplex virus 1/2, coxsackie virus, and parvovirus B19 were not detected in any case, while etiologies of 75% of the cases were still not confirmed. One out of the six adenovirus-infected patients died. The outcome significantly correlated with the severity of the liver disease.

Conclusion

This is the first report describing etiologies and characteristics of AHUE cases in Egypt, and interestingly, adenovirus was detected in adults. Further studies are required to determine the prevalence of this newly emerging viral hepatitis pathogens.

Epigallocatechin-3-gallate Mo nanoparticles (EGM NPs) efficiently treat liver injury by strongly reducing oxidative stress, inflammation and endoplasmic reticulum stress

Drug-induced liver injury (DILI) is a serious clinical disease associated with reactive oxygen species (ROS) burst and subsequent inflammatory responses. However, traditional treatments were limited by low efficacy and serious side effects due to the special liver structure. Here, we developed a molybdenum (Mo)-based nanoparticles, EGM NPs, after overall consideration of the pathophysiology of DILI and the advantages of nanodrugs. It demonstrated that EGM NPs treated acetaminophen (APAP)-induced DILI by scavenging ROS and inhibiting inflammation. EGM NPs effectively scavenged various ROS and reduced cell apoptosis at the cellular level. More importantly, EGM NPs can treat APAP-induced DILI in vivo, reducing the levels of liver function indicators in mice with liver injury, scaling down the area of hepatocyte necrosis and successfully inhibiting endoplasmic reticulum (ER) stress in the liver. EGM NPs also showed a certain anti-inflammatory effect by reducing infiltration of macrophages, decreasing pro-inflammatory factors and inhibiting the expression levels of inducible nitric oxide synthase (NOS2) and myeloperoxidase (MPO). Collectively, our findings suggest that EGM NPs-based nanotherapeutic is a novel strategy for the treatment of DILI.

Combinatorial targeting of G-protein-coupled bile acid receptor 1 and cysteinyl leukotriene receptor 1 reveals a mechanistic role for bile acids and leukotrienes in drug-induced liver injury

BACKGROUND AND AIM

Drug-induced liver injury (DILI) is a common disorder that involves both direct liver cell toxicity and immune activation. The bile acid receptor, G-protein-coupled bile acid receptor 1 (GPBAR1; Takeda G-protein-coupled receptor 5 [TGR5]), and cysteinyl leukotriene receptor (CYSLTR) 1 are G-protein-coupled receptors activated by bile acids and leukotrienes, exerting opposite effects on cell-to-cell adhesion, inflammation, and immune cell activation. To investigate whether GPBAR1 and CYSLTR1 mutually interact in the development of DILI, we developed an orally active small molecule, CHIN117, that functions as a GPBAR1 agonist and CYSLTR1 antagonist.

APPROACH AND RESULTS

RNA-sequencing analysis of liver explants showed that acetaminophen (APAP) intoxication positively modulates the leukotriene pathway, CYSLTR1, 5-lipoxygenase, and 5-lipoxygenase activating protein, whereas GPBAR1 gene expression was unchanged. In mice, acute liver injury induced by orally dosing APAP (500 mg/kg) was severely exacerbated by Gpbar1 gene ablation and attenuated by anti-Cysltr1 small interfering RNA pretreatment. Therapeutic dosing of wild-type mice with CHIN117 reversed the liver damage caused by APAP and modulated up to 1300 genes, including 38 chemokines and receptors, that were not shared by dosing mice with a selective GPBAR1 agonist or CYSLTR1 antagonist. Coexpression of the two receptors was detected in liver sinusoidal endothelial cells (LSECs), monocytes, and Kupffer cells, whereas combinatorial modulation of CYSLTR1 and GPBAR1 potently reversed LSEC/monocyte interactions. CHIN117 reversed liver damage and liver fibrosis in mice administered CCl₄ .

CONCLUSIONS

By genetic and pharmacological approaches, we demonstrated that GPBAR1 and CYSLTR1 mutually interact in the development of DILI. A combinatorial approach designed to activate GPBAR1 while inhibiting CYSLTR1 reverses liver injury in models of DILI.

Whole Exome Sequencing Reveals Genetic Variants in HLA Class II Genes Associated With Transplant-free Survival of Indeterminate Acute Liver Failure

INTRODUCTION

Indeterminate acute liver failure (IND-ALF) is a rare clinical syndrome with a high mortality rate. Lacking a known etiology makes rapid evaluation and treatment difficult, with liver transplantation often considered as the only therapeutic option. Our aim was to identify genetic variants from whole exome sequencing data that might be associated with IND-ALF clinical outcomes.

METHODS

Bioinformatics analysis was performed on whole exome sequencing data for 22 patients with IND-ALF. A 2-tier approach was used to identify significant single-nucleotide polymorphisms (SNPs) associated with IND-ALF clinical outcomes. Tier 1 identified the SNPs with a higher relative risk in the IND-ALF population compared with those identified in control populations. Tier 2 determined the SNPs connected to transplant-free survival and associated with model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

RESULTS

Thirty-one SNPs were found associated with a higher relative risk in the IND-ALF population compared with those in controls, of which 11 belong to the human leukocyte antigen (HLA) class II genes but none for the class I. Further analysis showed that 5 SNPs: rs796202376, rs139189937, and rs113473719 of HLA-DRB5; rs9272712 of HLA-DQA1; and rs747397929 of IDO1 were associated with a higher probability of IND-ALF transplant-free survival. Using 3 selected SNPs, a model for the polygenic risk score was developed to predict IND-ALF prognoses, which are comparable with those by model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

DISCUSSION

Certain gene variants in HLA-DRB5, HLA-DQA1, and IDO1 were found associated with IND-ALF transplant-free survival. Once validated, these identified SNPs may help elucidate the mechanism of IND-ALF and assist in its diagnosis and management.

Mitochondria-Targeted Fluorescence/Photoacoustic Dual-Modality Imaging Probe Tailored for Visual Precise Diagnosis of Drug-Induced Liver Injury

The multispectral optoacoustic tomography (MSOT) technique can be used to perform high-resolution molecular imaging under deep tissues, which gives the technology significant prospective for clinical application. Here, we developed a superoxide anion (O₂^•-)-activated MSOT and fluorescence dual-modality imaging probe (APSA) for early diagnosis of drug-induced liver injury (DILI). APSA can respond quickly to O₂^•-, resulting in an absorption peak blueshift from 845 to 690 nm, which also leads to the photoacoustic (PA) signal at 690 nm and the fluorescence signal at 748 nm increases linearly with increasing O₂^•- concentration, which can be utilized to assess the extent of liver damage. The developed MSOT imaging method can eliminate background interference from hematopoietic tissue by collecting the PA signals excited at 680, 690, 740, 760, 800, 845, and 900 nm wavelengths to achieve noninvasive in situ visual diagnosis of DILI. The developed fluorescence imaging method can be used for the imaging of endogenous O₂^•- in living cells and anatomic diagnosis of liver injury. The developed probe has broad application prospects in the early diagnosis of DILI.

Acute liver failure

PURPOSE OF REVIEW

Present an outline of acute liver failure, from its definition to its management in critical care, updated with findings of selected newer research.

RECENT FINDINGS

Survival of patients with acute liver failure has progressively improved. Intracranial hypertension complicating hepatic encephalopathy is now much less frequent than in the past and invasive ICP monitoring is now rarely used. Early renal replacement therapy and possibly therapeutic plasma exchange have consolidated their role in the treatment. Further evidence confirms the low incidence of bleeding in these patients despite striking abnormalities in standard tests of coagulation and new findings of abnormalities on thromboelastographic testing. Specific coagulopathy profiles including an abnormal vWF/ADAMTS13 ratio may be associated with poor outcome and increased bleeding risk. Use of N-acetylcysteine in nonparacetamol-related cases remains unsupported by robust clinical evidence. New microRNA-based prognostic markers to select patients for transplantation are described but are still far from widespread clinical applicability; imaging-based prognostication tools are also promising. The use of extracorporeal artificial liver devices in clinical practice is yet to be supported by evidence.

SUMMARY

Medical treatment of patients with acute liver failure is now associated with significantly improved survival. Better prognostication and selection for emergency liver transplant may further improve care for these patients.

Role of liver sinusoidal endothelial cells in liver diseases

Liver sinusoidal endothelial cells (LSECs) form the wall of the hepatic sinusoids. Unlike other capillaries, they lack an organized basement membrane and have cytoplasm that is penetrated by open fenestrae, making the hepatic microvascular endothelium discontinuous. LSECs have essential roles in the maintenance of hepatic homeostasis, including regulation of the vascular tone, inflammation and thrombosis, and they are essential for control of the hepatic immune response. On a background of acute or chronic liver injury, LSECs modify their phenotype and negatively affect neighbouring cells and liver disease pathophysiology. This Review describes the main functions and phenotypic dysregulations of LSECs in liver diseases, specifically in the context of acute injury (ischaemia-reperfusion injury, drug-induced liver injury and bacterial and viral infection), chronic liver disease (metabolism-associated liver disease, alcoholic steatohepatitis and chronic hepatotoxic injury) and hepatocellular carcinoma, and provides a comprehensive update of the role of LSECs as therapeutic targets for liver disease. Finally, we discuss the open questions in the field of LSEC pathobiology and future avenues of research.

Current concepts in acute liver failure

Acute liver failure (ALF) is a severe condition secondary to a myriad of causes associated with poor outcomes. The prompt diagnosis and identification of the aetiology allow the administration of specific treatments plus supportive strategies and to define the overall prognosis, the probability of developing complications and the need for liver transplantation. Pivotal issues are adequate monitoring and the institution of prophylactic strategies to reduce the risk of complications, such as progressive liver failure, cerebral oedema, renal failure, coagulopathies or infections. In this article, we review the main aspects of ALF, including the definition, diagnosis and complications. Also, we describe the standard-of-care strategies and recent advances in the treatment of ALF. Finally, we include our experience of care patients with ALF.

A sensitive upconverting nanoprobe based on signal amplification technology for real-time in situ monitoring of drug-induced liver injury

Drug-induced liver injury (DILI) is increasingly recognized as one of the most challenging global health problems. Conventional in vitro detection methods not only lack specificity and sensitivity but also cannot achieve real-time, straightforward visualization of hepatotoxicity in vivo. Liver-specific miR122 has been observed to be a superior and sensitive biomarker for DILI diagnosis. Herein, a sensitive upconverting nanoprobe synthesized with upconversion nanoparticles (UCNPs) and gold nanorods (GNR) was designed to diagnose hepatotoxicity in vivo. After injection, the nanoprobes accumulated in the liver and were activated by miR122, and the signal amplification technology fully yielded luminescent amplification; hence, the detection sensitivity was improved. Because of the high tissue penetration capability of near-infrared light, this nanoprobe can achieve real-time in situ detection, thereby providing a novel technology for precise biological and medical analysis.

Changing epidemiology of acute liver failure in Italy: a single-center experience over 25 years

BACKGROUND

Acute liver failure (ALF) is a rare but often lethal syndrome. In Italy, recent data on its incidence and causes are lacking. We report here the epidemiological analysis of ALF cases observed in Campania, a Southern Italian region, over the last 25 years.

METHODS

Medical records of ALF cases hospitalized from 1992 to 2018 were retrospectively analyzed.

RESULTS

Two hundred ten ALF cases occurred during 1992-2018: 103 (49%) hepatitis B virus (HBV)-related (including 5 cases also infected with Delta virus), 39 (19%) from undetermined cause, 36 (17%) drug-induced, 11 (5%) Wilson's disease-associated, 8 (4%) hepatitis A virus (HAV)-related and 12 (6%) from other causes. Separate time-periods analysis of data showed a significant progressive decrease in ALF incidence mainly attributable to a decline of HBV and other viruses etiology. Already before 2010, HAV or Delta virus-related cases have no longer been observed. No hepatitis C or E virus-related ALF was detected through the study period. A progressive decrease in frequency of ALF due to undetermined causes or drug was also evident.

CONCLUSIONS

A decrease in ALF incidence and a changing in its etiology were observed in Campania during 1992-2018. Both results were likely mainly due to 1991 introduction of HBV universal vaccination and may be considered generalizable nationwide.

Acute liver failure

Acute liver failure is a rare and severe consequence of abrupt hepatocyte injury, and can evolve over days or weeks to a lethal outcome. A variety of insults to liver cells result in a consistent pattern of rapid-onset elevation of aminotransferases, altered mentation, and disturbed coagulation. The absence of existing liver disease distinguishes acute liver failure from decompensated cirrhosis or acute-on-chronic liver failure. Causes of acute liver failure include paracetamol toxicity, hepatic ischaemia, viral and autoimmune hepatitis, and drug-induced liver injury from prescription drugs, and herbal and dietary supplements. Diagnosis requires careful review of medications taken, and serological testing for possible viral exposure. Because of its rarity, acute liver failure has not been studied in large, randomised trials, and most treatment recommendations represent expert opinion. Improvements in management have resulted in lower mortality, although liver transplantation, used in nearly 30% of patients with acute liver failure, still provides a life-saving alternative to medical management.

Drug-induced liver injury

Drug-induced liver injury (DILI) is an adverse reaction to drugs or other xenobiotics that occurs either as a predictable event when an individual is exposed to toxic doses of some compounds or as an unpredictable event with many drugs in common use. Drugs can be harmful to the liver in susceptible individuals owing to genetic and environmental risk factors. These risk factors modify hepatic metabolism and excretion of the DILI-causative agent leading to cellular stress, cell death, activation of an adaptive immune response and a failure to adapt, with progression to overt liver injury. Idiosyncratic DILI is a relative rare hepatic disorder but can be severe and, in some cases, fatal, presenting with a variety of phenotypes, which mimic other hepatic diseases. The diagnosis of DILI relies on the exclusion of other aetiologies of liver disease as specific biomarkers are still lacking. Clinical scales such as CIOMS/RUCAM can support the diagnostic process but need refinement. A number of clinical variables, validated in prospective cohorts, can be used to predict a more severe DILI outcome. Although no pharmacological therapy has been adequately tested in randomized clinical trials, corticosteroids can be useful, particularly in the emergent form of DILI related to immune-checkpoint inhibitors in patients with cancer.

Epidemiology and outcomes of acute liver failure in Australia

BACKGROUND

Acute liver failure (ALF) is a life-threatening syndrome with varying aetiologies requiring complex care and multidisciplinary management. Its changing incidence, aetiology and outcomes over the last 16 years in the Australian context remain uncertain.

AIM

To describe the changing incidence, aetiology and outcomes of ALF in South Eastern Australia.

METHODS

The database of the Victorian Liver Transplant Unit was interrogated to identify all cases of ALF in adults (> 16 years) in adults hospitalised between January 2002 and December 2017. Overall, 169 patients meeting criteria for ALF were identified. Demographics, aetiology of ALF, rates of transplantation and outcomes were collected for all patients. Transplant free survival and overall survival (OS) were assessed based on survival to discharge from hospital. Results were compared to data from a historical cohort from the same unit from 1988-2001.

RESULTS

Paracetamol was the most common aetiology of acute liver failure, accounting for 50% of cases, with an increased incidence compared with the historical cohort (P = 0.046). Viral hepatitis and non-paracetamol drug or toxin induced liver injury accounted for 15% and 10% of cases respectively. Transplant free survival (TFS) improved significantly compared to the historical cohort (52% vs 38%, P = 0.032). TFS was highest in paracetamol toxicity with spontaneous recovery in 72% of cases compared to 31% of non-paracetamol ALF (P < 0.001). Fifty-nine patients were waitlisted for emergency liver transplantation. Nine of these died while waiting for an organ to become available. Forty-two patients (25%) underwent emergency liver transplantation with a 1, 3 and 5 year survival of 81%, 78% and 72% respectively.

CONCLUSION

Paracetamol toxicity is the most common aetiology of ALF in South-Eastern Australia with a rising incidence over 30 years. TFS has improved, however it remains low in non-paracetamol ALF.

The incidence, etiologies, outcomes, and predictors of mortality of acute liver failure in Thailand: a population-base study

BACKGROUND

Acute liver failure (ALF) is uncommon but progresses rapidly with high mortality. We investigated the incidence, etiologies, outcomes, and predictive factors for 30-day mortality in patients with ALF.

METHODS

We conducted a population-based study of ALF patients hospitalized between 2009 and 2013 from the Thai Nationwide Hospital Admission database, which comprises 76% of all admissions from 858 hospitals across 77 provinces in Thailand. ALF was diagnosed using ICD-10 codes K72.0 and K71.11. Patients with liver cirrhosis were excluded.

RESULTS

There were 20,589 patients diagnosed with ALF during the study period with 12,277 (59.6%) males and mean age of 46.6 ± 20.7 years. The incidence of ALF was 62.9 per million population per year. The most frequent causes of ALF were indeterminate (69.4%), non-acetaminophen drug-induced (26.1%), and viral hepatitis (2.5%). Acetaminophen was the presumptive cause in 1.7% of patients. There were 5502 patients (26.7%) who died within 30 days after admission. One patient (0.005%) underwent liver transplantation. The average hospital stay was 8.7 ± 13.9 days, and the total cost of management was 1075.2 ± 2718.9 USD per admission. The most prevalent complications were acute renal failure (ARF)(24.2%), septicemia (18.2%), and pneumonia (12.3%). The most influential predictive factors for 30-day mortality were ARF (HR = 3.64, 95% CI: 3.43-3.87, p < 0.001), malignant infiltration of the liver (HR = 3.37, 95% CI: 2.94-3.85, p < 0.001), and septicemia (HR = 1.96, 95%CI: 1.84-2.08, p < 0.001).

CONCLUSIONS

ALF patients have poor outcomes with 30-day mortality of 26.7% and high economic burden. Indeterminate etiology is the most frequent cause. ARF, malignant infiltration of the liver, and septicemia are main predictors of 30-day mortality.

Outcome of Acetaminophen-Induced Acute Liver Failure Managed Without Intracranial Pressure Monitoring or Transplantation

Acetaminophen-induced acute liver failure (ALF) may require emergency liver transplantation (LT) in the presence of specific criteria, and its management may also include intracranial pressure (ICP) monitoring in selected patients at high risk of cerebral edema. We aimed to test the hypothesis that management of such patients without ICP monitoring or LT would yield outcomes similar to those reported with conventional management. We interrogated a database of all patients treated in an intensive care unit for acetaminophen-induced ALF between November 2010 and October 2016 and obtained relevant information from electronic medical records. We studied 64 patients (58 females) with a median age of 38 years. Such patients had a high prevalence of depression, substance abuse, or other psychiatric disorders and had ingested a median acetaminophen dose of 25 g. No patient received ICP monitoring or LT. Overall, 51 (79.7%) patients survived. Of the 42 patients who met King's College Hospital (KCH) criteria, 29 (69.0%) survived without transplantation. There were 45 patients who developed severe hepatic encephalopathy, and 32 (71.1%) of these survived. Finally, compared with the KCH criteria, the current UK Registration Criteria for Super-Urgent Liver Transplantation (UKRC) for super-urgent LT had better sensitivity (92.3%) and specificity (80.4%) for hospital mortality. In conclusion, in a center applying a no ICP monitoring and no LT approach to the management of acetaminophen-induced ALF, during a 6-year period, overall survival was 79.7%, and for patients fulfilling KCH criteria, it was 69.0%, which were both higher than for equivalent patients treated with conventional management as reported in the literature. Finally, the current UKRC may be a better predictor of hospital mortality in this patient population.

Marked Decrease in Urgent Listing for Liver Transplantation Over Time: Evolution of Characteristics and Outcomes of Status-1 Liver Transplantation

BACKGROUND

Approximately 5% of liver transplants annually are performed urgently with "status-1" designation. This study aims to determine if the demand, characteristics, and outcome for status-1 liver transplantation has changed over time.

METHODS

We used the Scientific Registry of Transplant Patients (2003-2015) to characterize 2352 adult patients who underwent 2408 status-1 liver transplants and compared them between Era1 (2003-6/2009) and Era2 (7/2009-2015).

RESULTS

Overall, there were fewer liver transplants performed with the status-1 designation in Era2 than Era1 (1099 vs 1309). Although the number of urgent liver transplants was relatively constant with successive years, the proportion transplanted with status-1 designation decreased markedly over time. Era2 patients were older (43.2 years vs 41.7 years, P = 0.01) and less likely be ABO-incompatible (1.1% vs 2.4%, P = 0.01) or retransplant (77 vs 124, P = 0.03). In terms of disease etiology, the largest group was "acute liver failure (ALF), nonspecified" (43.4%). There was no difference in proportion with drug-induced liver injury (DILI), but the subset of herbal/dietary supplements increased in Era2 (1.3% vs 0.46%, P = 0.04). Survival was increased in Era2 in the overall cohort and for patients with autoimmune disease (P < 0.05), despite longer waiting times for this etiology (186 days vs 149 days). DILI or nonspecified ALF had shorter waiting times, and 90% were transplanted within 7 days.

CONCLUSIONS

Liver transplantation for the most urgent indications (status-1) is decreasing while survival remains excellent. Fewer incidences of ALF are classified as indeterminate, mostly as a result of increasing awareness of autoimmune hepatitis and DILI as causes of the syndrome.

Acute Liver Failure of Indeterminate Etiology: A Comprehensive Systematic Approach by An Expert Committee to Establish Causality

OBJECTIVES

In the United States, the Acute Liver Failure Study Group (ALFSG) registry lists approximately 11% of cases as of indeterminate etiology (IND-ALF) as determined by the respective local site principal investigator (PI). Traditionally, IND-ALF has prompted concern that other viruses or toxins might be implicated. We hypothesized that many IND- ALF cases would have an identifiable etiology upon further investigation. Improving the identification process should reduce the number of truly indeterminate cases.

METHODS

Specific definitions for each etiology ("etiology-specific algorithms") were developed by a Causality Adjudication Committee that included six reviewers (each with 20 or more years of experience). Of 2718 patients with ALF, 303 initially deemed IND-ALF by site PIs underwent committee review guided by the algorithms. Acetaminophen (APAP) protein adducts were measured in sera when available, additional HEV testing was performed, and viral sequences sought by microarray analysis and metagenomic next-generation sequencing (mNGS). Study sites were asked to provide liver biopsy and/or explant reports and to update serological findings not reported previously.

RESULTS

Nearly half (142, 46.9%) of the 303 IND-ALF cases could be reassigned to a single, defined etiology and rated as highly likely or probable; 11 additional cases, upon review, did not meet ALF criteria. Amongst reassigned etiologies, 45 were previously unrecognized APAP, 34 autoimmune hepatitis (AIH), 24 drug-induced liver injury (DILI), 13 various viral causes, 12 ischemia, and 14 miscellaneous other etiologies. The remaining 150, deemed true IND-ALF, represented just 5.5%.

CONCLUSIONS

The indeterminate etiology in ALF includes patients with a diagnosis that is discernible after closer examination. Revision of etiologic diagnoses of indeterminate cases using added testing and expert opinion is useful in understanding all aspects of ALF.

Beyond KCH selection and options in acute liver failure

The King’s prognostic criteria for patients with acute liver failure (ALF) introduced in 1989 have been used worldwide. This distinguished for the first time cases with ‘hyper-acute’ course (characteristically paracetamol overdose) where there is a better chance of recovery with medical supportive care alone from those etiologies with a less acute course and paradoxically lower chances of ‘spontaneous’ recovery. Ongoing use showed the limited sensitivity of the criteria to constitute a significant practical limitation. Subsequent models including the MELD score and composite ones with markers of necrosis, an apoptotic liver cell death, proposed to improve sensitivity did not have the required high specificity. Two recent models utilizing new availability of web- and app-based computing delivering outcome predication through sophisticated algorithms are described. The first is a dynamic model described for paracetamol-induced ALF based upon admission findings and sequential variables over the first 2 days. The new model of the US Acute Liver Failure group was devised to cover all etiologies of ALF for predicting ‘transplant-free’ survival and accurately predicated spontaneous survival in two-thirds of cases. Improved survival results with medical management, particularly in hyper-acute cases, now approach those obtained with successful liver transplant and have raised the question of transplant benefit. Also considered in the review are new non-transplant approaches to treatment including the use of plasma exchange and based on successful results in acute-on-chronic liver failure, agents to modulate and improve hepatic regeneration.

Acetaminophen (APAP or N-Acetyl-p-Aminophenol) and Acute Liver Failure

Acetaminophen (APAP) is the leading cause of acute liver failure (ALF), although the worldwide frequency is variable. APAP hepatotoxicity develops either following intentional overdose or unintentional ingestion (therapeutic misadventure) in the background of several factors, such as concomitant use of alcohol and certain medications that facilitate the formation of reactive and toxic metabolites. Spontaneous survival is more common in APAP-induced ALF compared with non-APAP etiologies. N-acetylcysteine is recommended for all patients with APAP-induced ALF and it reduces mortality. Liver transplantation should be offered early to those who are unlikely to survive based on described prognostic criteria.

Systematic review: non A-E, seronegative or indeterminate hepatitis; what is this deadly disease?

BACKGROUND

A significant proportion of cases of acute liver failure (ALF) do not have an identifiable cause; so called "non A-E," "non A, non B, non C," "seronegative" or "indeterminate" hepatitis. However, this entity is clinically not well described.

AIM

To collate the known incidence and outcomes in indeterminate hepatitis. This systematic review sought to identify potential aetiologies that ought to be considered, and identify likely future objectives in classification and treatment strategies for indeterminate hepatitis.

METHODS

Literature review to determine aetiological factors, prevalence and outcomes relating to indeterminate hepatitis.

RESULTS

There is significant heterogeneity within the reported cases of indeterminate hepatitis in the literature. Some of the potential infective aetiologies which are reviewed here include: parvovirus B19 (PVB19), herpes simplex virus (HSV), Toga-Like Virus and the Annelloviridae (including SEN-V). Interestingly, this condition predominately affects middle aged women, with subacute progression of the liver failure. In addition, the prognosis of indeterminate hepatitis is poor, with reduced spontaneous survival compared with other causes of acute liver failure and increased need for emergency liver transplantation.

CONCLUSIONS

Whilst various pathological processes have been implicated in the development of indeterminate hepatitis, the specific cause remains elusive. There is an urgent need for general consensus on a specific definition and exclusion of confounding aetiologies with coordinated multicentre investigation of this rare condition to identify aetiology and develop therapies to reduce the significant mortality and need for emergency liver transplantation associated with this condition.