Systematic review of the global epidemiology of viral-induced acute liver failure

The emerging role of alternatively activated macrophages to treat acute liver injury

Acute liver injury (ALI) has a clear requirement for novel therapies. One emerging option is the use of alternatively activated macrophages (AAMs); a distinct subtype of macrophage with a role in liver injury control and repair. In this comprehensive review, we provide an overview of the current limited options for ALI, and the potential advantages offered by AAMs. We describe the evidence supporting their use from in vitro studies, pre-clinical animal studies, and human clinical trials. We suggest why the first evidence for the clinical use of AAMs is likely to be found in acetaminophen toxicity, and discuss the specific evidence for AAM use in this population, as well as potential applications for AAMs in other patient populations. The key domains by which the performance of AAMs for the treatment of ALI will be assessed are identified, and remaining challenges to the successful delivery of AAMs to clinic are explored.

Evolution and Impact of Hepatitis A Epidemiology in Europe-Systematic Literature Review of the Last 20 Years

While globally hepatitis A (hepA) infections occur in 150 million people annually, European high-income countries now have a low endemicity. However, this results in a more susceptible adult population which is prone to severe illness. To determine current epidemiological characteristics, we performed a systematic literature review to assess the severity of hepA disease in the past two decades in 11 European countries (i.e., Denmark, France, Germany, Greece, Hungary, Italy, the Netherlands, Spain, Sweden, Switzerland and the United Kingdom). Literature search was performed using PubMed and Embase between 1 January 2001 and 14 April 2021. Search terms included the disease (hepA), the 11 selected countries, the term 'outbreaks' and its synonyms, outcomes and terms for hepA virus circulation. In total, 43 records reported data on hepA disease outcomes. Hospitalisation rates varied between the countries, with annual rates exceeding 50% at least once in seven countries. The lowest hospitalisation rates were reported for the Netherlands (≤ 32%) and the highest for Greece (≥ 81%). Liver failure, haemorrhagic and other complications were rarely reported, and case fatality rates were low (0.03%-0.26%). Our findings are consistent with the trends observed globally. This systematic literature review highlights the need to increase awareness of hepA risks and to strengthen prevention strategies. Continuous monitoring of epidemiological data is crucial to assess which populations would most benefit from prevention, mainly with respect to future vaccination recommendations.

Epidemiological insights into severe hepatitis in pediatric inpatients

There is limited statistical data on severe hepatitis among hospitalized children in China at a national level. This nationwide study analyzed data from 34,410 children hospitalized for severe hepatitis in mainland China from 2016 to 2022. The overall in-hospital mortality rate was 6.1%. Viral hepatitis accounted for 14.9% of cases, with hepatitis B being the most prevalent. Indeterminate etiology, present in 79.0% of cases, was an independent risk factor for mortality. Findings emphasize the need for enhanced diagnostic methods and targeted interventions for children with severe hepatitis of unknown cause and suggest focused hepatitis B monitoring in older children to improve outcomes. Establishing a dedicated surveillance system is crucial for improving the prognosis of children at high risk for in-hospital mortality due to severe hepatitis.

Definitions, etiopathogenesis and epidemiology of ALF

Acute liver failure (ALF) is a rare but preventable cause of acute hepatic dysfunction which is associated with significant mortality, unless treated appropriately. There are significant regional variations in the etiologies of ALF globally and this determines the outcomes of the disease as well as the long-term survival in patients receiving liver transplantation for management. Improvements in understanding of disease pathophysiology and critical care medicine have led to better outcomes over the last few decades. Despite this, the burden of indeterminate ALF and the pathogenesis of many etiological agents are yet to be fully known. Improvements in diagnostic and prognostic modalities are expected to decrease the morbidity and mortality associated with ALF. Changes in vaccination programs and stronger legislative practices regarding over-the-counter sale of acetaminophen and non-proprietary drugs are expected to reduce the burden of disease globally.

Viral etiologies of acute liver failure

Acute liver failure (ALF) is a rare cause of liver-related mortality worldwide, with an estimated annual global incidence of more than one million cases. While drug-induced liver injury, including acetaminophen toxicity, is the leading cause of ALF in the Western world, viral infections remain a significant cause of ALF and the most common cause in many developing nations. Given the high mortality rates associated with ALF, healthcare providers should be aware of the broad range of viral infections that have been implicated to enable early diagnosis, rapid treatment initiation when possible, and optimal management, which may include liver transplantation. This review aims to provide a summary of viral causes of ALF, diagnostic approaches, treatment options, and expected outcomes.

Acute liver failure

Acute liver failure (ALF) is a life-threatening disorder characterised by rapid deterioration of liver function, coagulopathy, and hepatic encephalopathy in the absence of pre-existing liver disease. The cause of ALF varies across the world. Common causes of ALF in adults include drug toxicity, hepatotropic and non-hepatotropic viruses, herbal and dietary supplements, antituberculosis drugs, and autoimmune hepatitis. The cause of liver failure affects the management and prognosis, and therefore extensive investigation for cause is strongly suggested. Sepsis with multiorgan failure and cerebral oedema remain the leading causes of death in patients with ALF and early identification and appropriate management can alter the course of ALF. Liver transplantation is the best current therapy, although the role of artificial liver support systems, particularly therapeutic plasma exchange, can be useful for patients with ALF, especially in non-transplant centres. In this Seminar, we discuss the cause, prognostic models, and management of ALF.

Acute liver failure: Management update and prognosis

Acute liver failure is a rare but serious syndrome, with an incidence of approximately 2,000 to 3,000 cases per year in North America. Its pathophysiology and clinical course vary, depending on the cause of the primary liver injury, and can lead to high morbidity and mortality or the need for liver transplantation, despite available therapies. This syndrome involves excessive activation of the immune system, with damage in other organs, contributing to its high mortality rate. The most accepted definition includes liver injury with hepatic encephalopathy and coagulopathy within the past 26 weeks in a patient with no previous liver disease. The main causes are paracetamol poisoning, viral hepatitis, and drug-induced liver injury, among others. Identifying the cause is crucial, given that it influences prognosis and treatment. Survival has improved with supportive measures, intensive therapy, complication prevention, and the use of medications, such as N-acetylcysteine. Liver transplantation is a curative option for nonresponders to medical treatment, but adequate evaluation of transplantation timing is vital for improving results. Factors such as patient age, underlying cause, and severity of organ failure influence the post-transplant outcomes and survival.

Epidemiology of acute liver failure in Egyptian children

Background

Acute liver failure (ALF) is a serious condition that refers to the development of synthetic function impairment after severe acute liver injury in an individual without pre-existing liver disease. Understanding the epidemiology of ALF in children constitutes a cornerstone in its preventive and treatment plans. Nevertheless, there is a lack of information about its epidemiology in Egypt.

Objective

The aim of this study was to assess the epidemiologic data of ALF in Egyptian children.

Patients and methods

The medical records of children with ALF aged from 6 months to 18 years who were admitted from 2015 to 2020 were analyzed to identify the patient’s epidemiologic, laboratory, and investigational data together with their outcome.

Results

The study included 154 patients who fulfilled the definition of ALF were included. Their age ranged from 7 months to 17 years, with a median of 5.8 years. Hepatitis A virus (HAV) was the most commonly identifiable etiology (37.7%). Mortality was the outcome for 73 patients (47.4%). The prognostic factors associated with mortality were elevated international normalized ratio (INR), total bilirubin (TB), creatinine, and ammonia levels at presentation with cutoff values (2.97, 21.15, 0.385, and 212, respectively).

Conclusion

Hepatitis A virus is the most commonly identified etiology of ALF in Egyptian children. The mortality rate is high, and most of the deaths occurred early in the first 5 days of admission. So, early preparation for liver transplantation is recommended. Higher values of INR, TB, and creatinine above the cutoff levels at presentation may be potential markers for predicting death in affected children.

Clinical epidemiology and outcomes of emergency department-acute kidney injury: A systematic review

Background

Over half of all community-acquired acute kidney injury (CA-AKI) initially presented to emergency department (ED), but emergency department acute kidney injury (ED-AKI) is poorly characterised, poorly understood with no systematic review, often under-recognized and under-managed.

Objective

To review the incidence, risk factors, and outcomes of ED-AKI, and risk factors of post-ED-AKI mortality globally.

Methods

We included published prospective or retrospective observational studies, controlled trials, and systematic reviews reporting AKI in adult ED attendees within 24 h of ED admission. Iatrogenic causes of AKI from medical interventions were excluded. We used PubMed to identify articles from 1996 to August 14, 2021, and adopted the National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies to assess risk of bias. We used a Forest plot to present pooled ED-AKI incidence rates and I2 statistics. Other parameters were summarized narratively.

Results

Using 24 h from ED admission as the definition for ED-AKI we identified six articles from 2005 to 2018 in high-income settings and one article with a 48-h timeframe. The pooled incidence of ED-AKI was 20 per 1000 adult ED attendances. Risk factors for ED-AKI included increasing age, nursing home residence, previous hospital admission within 30 days, discharge diagnosis of diabetes, obstructive uropathy, sepsis, gastrointestinal medical conditions, high serum creatinine, bilirubin, C-reactive protein, white blood cell, alanine aminotransferase, low serum sodium or albumin on admission, poor premorbid renal function, antibiotic use, active malignancy, lung disease, hyperlipidaemia, and infection. Crude, all-cause 24-h mortality rate was 4.56 % and the one-year mortality rate was 35.04 %. Increasing age and comorbidities including cardiovascular disease and malignancy were associated with higher mortality rates.

Conclusion

The review reveals a paucity of relevant literature which calls for further research, increased vigilance, red flag identification, and standardized management protocols for ED-AKI.

The Use and Potential Benefits of N-Acetylcysteine in Non-Acetaminophen Acute Liver Failure: An Etiology-Based Review

Acute liver failure represents a life-threatening organ dysfunction with high mortality rates and an urgent need for liver transplantation. The etiology of the disease varies widely depending on various socio-economic factors and is represented mainly by paracetamol overdose and other drug-induced forms of liver dysfunction in the developed world and by viral hepatitis and mushroom poisoning in less developed countries. Current medical care constitutes either specific antidotes or supportive measures to ensure spontaneous recovery. Although it has been proven to have beneficial effects in paracetamol-induced liver failure, N-acetylcysteine is widely used for all forms of acute liver failure. Despite this, few well-designed studies have been conducted on the assessment of the potential benefits, dose regimens, or route of administration of N-acetylcysteine in non-acetaminophen liver failure. This review aims to summarize the current evidence behind the use of this drug in different forms of liver failure.

[Advancements in the diagnosis and treatment of pediatric acute liver failure]

Pediatric acute liver failure (PALF) is a rare and rapidly progressive clinical syndrome with a poor prognosis and significant mortality. The etiology of PALF is complex, and it presents with diverse and atypical clinical manifestations. Accurate diagnosis based on age-related factors, early recognition or prevention of hepatic encephalopathy, and precise supportive treatment targeting the underlying cause are crucial for improving outcomes and prognosis. This article provides a comprehensive review of recent research on the diagnosis and treatment of PALF, aiming to offer guidance for clinical practice.

Acute liver failure in low-income and middle-income countries

Acute liver failure is a rare condition involving the rapid development, progression, and worsening of liver dysfunction, characterised by coagulopathy and encephalopathy, and has a high mortality unless liver transplantation is performed. Population-based studies are scarce, and most published data are from high-income countries, where the main cause of acute liver failure is paracetamol overdose. This Review provides an overview of the scanty literature on acute liver failure in low-income and middle-income countries, where patients are often admitted to primary care hospitals and viral hepatitis (especially hepatitis E), tropical infections (eg, dengue), traditional medicines, and drugs (especially anti-tuberculosis drugs) have an important role. We discuss incidence, cause, occurrence in children and pregnant women, prognostic factors and scores, treatment, and mortality. To conclude, we advocate for international collaboration, the establishment of central registries for the condition, and better diagnostics.

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.

Acute Liver Failure in Dengue: A Common but Overlooked Entity in Pediatric Patients in Tropical Countries

OBJECTIVE

The objective of the study is to estimate the incidence of acute liver failure (ALF) in dengue infection, understand the demographic and biochemical profiles, and identify prognostic factors associated with mortality.

METHODOLOGY

This is a retrospective observational study. We evaluated the data of all pediatric dengue patients admitted over the last 5 years in our hospital to identify patients who fulfilled the criteria for pediatric ALF. Demographic profile, and biochemical and radiological parameters were assessed. Their outcomes and mortality data were analyzed to identify prognostic factors.

RESULTS

Thirty children with dengue infection were identified to have developed a during the ALF study period which was 29.1% (30 of 103) of all our ALF admissions. A total of 189 children with dengue infection needed admission during the same period and 15.8% (30 of 189) of them developed ALF. The mean duration of onset of ALF was 5.4 days after fever onset. Twenty-two patients (73%) survived, and 8 patients expired. High creatinine, low albumin level, and multisystemic involvement were identified as poor prognostic markers in those patients who did not survive.

CONCLUSION

ALF is common in admitted severe dengue patients. A significant proportion of acute liver patients in endemic countries can be attributed to dengue infection. Low serum albumin, high creatinine, and multi-organ dysfunction during acute illness can be used as prognostic markers in these children. Multicentric prospective studies are needed to validate these results.

Acute Hepatitis of Unknown Origin in Pediatric Age Group: Recent Outbreaks and Approach to Management

Acute hepatitis has always been a public health concern, but the recent clustering of cases in various parts of the world has drawn some special attention. The sudden rise in cases has mainly been among the pediatric population of around 35 countries around the world, including developed countries such as the United States, the United Kingdom, and European countries. The outbreaks have had a devastating impact, with around 10% of the affected patients developing liver failure. The clinical presentation of patients resembles any other case of acute hepatitis, with the major symptoms being: jaundice (68.8%), vomiting (57.6%), and gastrointestinal symptoms such as abdominal pain (36.1%) and nausea (25.7%). Interestingly, the cases have tested negative for hepatotropic viruses Hep A, B, C, and E, thus giving rise to the terms Hepatitis of Unknown Origin or non-HepA-E hepatitis. Many causes have been attributed to the disease, with major evidence seen for adenovirus and SARS-CoV-2. International agencies have stressed on establishing diagnostic and management protocols to limit these outbreaks. As the understanding has evolved over time, diagnostic and management faculties have found more shape. The current review was designed to comprehensively compile all existing data and whittle it down to evidence-based conclusions to help clinicians.

Review of clinical characteristics, immune responses and regulatory mechanisms of hepatitis E-associated liver failure

Hepatitis E virus (HEV) is the most common cause of acute liver failure (LF) and one of the most common factors causing acute injury in acute-on-chronic LF (ACLF). When HEV-related LF occurs, a series of changes take place in both the intrahepatic environment and extrahepatic microenvironment. The changed types and distribution of immune cells (infiltrating macrophages and increased lymphocytes) in liver tissue, as well the increased proinflammatory cytokines and chemokines in the blood, indicate that the occurrence and progression of HEV-related LF are closely related to immune imbalance. The clinical features and immune reaction in the body during HEV-related acute LF (ALF) and ACLF are complicated. This review highlights recent progress in elucidating the clinical manifestations of HEV-associated ALF and ACLF and discusses the corresponding systemic immune changes and possible regulatory mechanisms.

The recent outbreak of acute and severe hepatitis of unknown etiology in children: a possible role of human adenovirus infection?

The Public Health Scotland (PHS) was notified at the end of March 2022 that five children aged 3-5 years had presented to the Royal Hospital for Children in Glasgow with acute hepatitis of unknown etiology within a three-week period.Keywords This article is protected by copyright. All rights reserved.

Acute, Severe Hepatitis of Unknown Origin: Should We Really Be Afraid of Another Obscure Enemy of Our Children?

On 31 March 2022, Public Health Scotland was alerted to five children aged 3-5 years, presenting to the Glasgow children's hospital with severe hepatitis of unknown etiology within a 3-week period [...].

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.

Hepatitis E in immunocompromised individuals

Hepatitis E virus (HEV) originally identified as a cause of acute icteric hepatitis in developing countries has grown to be a cause of zoonotic viral hepatitis in developed countries such as the United States. While there are eight identified genotypes to date, genotype 1 (HEV1), HEV2, HEV3, HEV4 are the most common to infect humans. HEV1 and HEV2 are most common in developing countries including Latina America, Africa and Asia, and are commonly transmitted through contaminated water supplies leading to regional outbreaks. In contrast HEV3 and HEV4 circulate freely in many mammalian animals and can lead to occasional transmission to humans through fecal contamination or consumption of undercooked meat. The incidence and prevalence of HEV in the United States is undetermined given the absence of FDA approved serological assays and the lack of commercially available testing. In majority of cases, HEV infection is a self-limiting hepatitis requiring only symptomatic treatment. However, this is not the case in immunocompromised individuals, including those that have undergone solid organ or stem cell transplantation. In this subset of patients, chronic infection can be life threatening as hepatic insult can lead to inflammation and fibrosis with subsequent cirrhosis and death. The need for re-transplantation as a result of post-transplant hepatitis is of great concern. In addition, there have been many reported incidents of extrahepatic manifestations, for which the exact mechanisms remain to be elucidated. The cornerstone of treatment in immunocompromised solid organ transplant recipients is reduction of immunosuppressive therapies, while attempting to minimize the risk of organ rejection. Subsequent treatment options include ribavirin, and pegylated interferon alpha in those who have demonstrated ribavirin resistance. Further investigation assessing safety and efficacy of anti-viral therapy is imperative given the rising global health burden. Given this concern, vaccination has been approved in China with other investigations underway throughout the world. In this review we introduce the epidemiology, diagnosis, clinical manifestations, and treatment of HEV, with emphasis on immunocompromised individuals in the United States.

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper on the Diagnosis and Management of Pediatric Acute Liver Failure

ABSTRACT

Pediatric acute liver failure (PALF) is a rare, rapidly progressive clinical syndrome with significant morbidity and mortality. The phenotype of PALF manifests as abrupt onset liver dysfunction, which can be brought via disparate etiology. Management is reliant upon intensive clinical care and support, often provided by the collaborative efforts of hepatologists, critical care specialists, and liver transplant surgeons. The construction of an age-based diagnostic approach, the identification of a potential underlying cause, and the prompt implementation of appropriate therapy can be lifesaving; however, the dynamic and rapidly progressive nature of PALF also demands that diagnostic inquiries be paired with monitoring strategies for the recognition and treatment of common complications of PALF. Although liver transplantation can provide a potential life-saving therapeutic option, the ability to confidently determine the certainness that liver transplant is needed for an individual child has been hampered by a lack of adequately tested clinical decision support tools and accurate predictive models. Given the accelerated progress in understanding PALF, we will provide clinical guidance to pediatric gastroenterologists and other pediatric providers caring for children with PALF by presenting the most recent advances in diagnosis, management, pathophysiology, and associated outcomes.

Mahuang Decoction Antagonizes Acute Liver Failure via Modulating Tricarboxylic Acid Cycle and Amino Acids Metabolism

Acute liver failure (ALF) is a serious clinical disorder with high fatality rates. Mahuang decoction (MHD), a well-known traditional Chinese medicine, has multiple pharmacological effects, such as anti-inflammation, anti-allergy, anti-asthma, and anti-hyperglycemia. In this study, we investigated the protective effect of MHD against ALF. In the lipopolysaccharide and D-galactosamine (LPS/D-GalN)-induced ALF mouse model, the elevated activities of the serum alanine and aspartate transaminases as well as the liver pathological damage were markedly alleviated by MHD. Subsequently, a metabolomics study based on the ultrahigh performance liquid chromatograph coupled with Q Exactive Orbitrap mass spectrometry was carried to clarify the therapeutic mechanisms of MHD against ALF. A total of 36 metabolites contributing to LPS/D-GalN-induced ALF were identified in the serum samples, among which the abnormalities of 27 metabolites were ameliorated by MHD. The analysis of metabolic pathways revealed that the therapeutic effects of MHD are likely due to the modulation of the metabolic disorders of tricarboxylic acid (TCA) cycle, retinol metabolism, tryptophan metabolism, arginine and proline metabolism, nicotinate and nicotinamide metabolism, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan synthesis, as well as cysteine and methionine metabolism. This study demonstrated for the first time that MHD exerted an obvious protective effect against ALF mainly through the regulation of TCA cycle and amino acid metabolism, highlighting the importance of metabolomics to investigate the drug-targeted metabolic pathways.