Acute liver failure in children

Severe acute hepatitis of unknown origin in children: Is it still a mystery? What role does adenovirus play?

On March 31, 2022, severe acute hepatitis of unknown origin was first reported from the Royal Glasgow Children's Hospital in Scotland. According to the criteria by WHO-ECDC, a probable case of unknown acute hepatitis in children is defined as a subject under 16 years of age, who tested negative for viral hepatitis and transaminases >500 U/L, starting from the 1st of October 2021. WHO invites Member States to participate in the global effort to collect anonymized clinical data on probable cases of severe acute hepatitis of unknown aetiology. As of May 26, 2021, 650 cases were already registered on the platform worldwide, of whom at least 38 cases have required liver transplants. Several hypotheses such as previous SARS-CoV-2 infection or coinfection or infection with another virus were examined and a strong association was found between adenovirus (41F) and acute hepatitis of unknown aetiology cases. This review article summarizes the global epidemiological evidences on acute hepatitis of unknown origin in children, analysing their incidence and characteristics.

Efficacy of steroid therapy for improving native liver survival after pediatric acute liver failure with immune activation

AIM

Recent evidence suggests that acute liver failure (ALF) in some patients may reflect a dysregulated immune response, and that corticosteroids improve survival of the native liver in ALF patients with high serum alanine aminotransferase levels, which are an indication of liver inflammation. However, it is unclear whether steroids are effective for pediatric acute liver failure (PALF). The aim of this retrospective case-control study is to examine whether steroid therapy for PALF accompanied by immune activation improves the survival of native liver and to identify factors that predict responses to steroid treatment.

METHODS

Of 38 patients with PALF treated at Kyoto University Hospital from February 2006 to August 2022, 19 receiving steroids who met the specific criteria for identifying the pathophysiology of immune activity in the liver (the "Steroid group"), and seven steroid-free patients who also met the criteria ("Nonsteroid group") were enrolled. Patients in the "Steroid group" were categorized as "responders" or "nonresponders" according to treatment outcome. Clinical and histological data were analyzed.

RESULTS

Survival of the native liver in the Steroid group was significantly higher than that in the Nonsteroid group (68% vs. 0%, respectively; p = 0.0052). Nonresponders were significantly younger, with higher Model for End-stage Liver Disease and pediatric end-stage liver disease scores, higher prothrombin time - international normalized ratio, and higher serum ferritin levels than responders. Massive hepatic necrosis was more common in nonresponders.

CONCLUSION

Steroid therapy is effective for PALF patients with liver inflammation; however, liver transplantation should be prioritized for young children with ALF accompanied by severe coagulopathy or massive hepatic necrosis.

Could Herpesviridae be the cause of severe acute hepatitis of unknown origin in children?

INTRODUCTION

Severe acute hepatitis (SAH) is defined by a severe inflammation of hepatocytes in the liver parenchyma which can lead to an acute liver failure, a clinical condition with high mortality rate that can be triggered by several factors but is usually associated to hepatotropic viruses' infection. In 2022, cases of children with severe acute hepatitis of unknown origin hospitalized in Glasgow, Scotland, were reported. Possible causes of this condition include, but are not limited to, undiagnosed viral (and non-viral) infections, autoimmune hepatitis, drug and/or chemical toxicity, mitochondrial chain respiratory and metabolic disorders.

AREAS COVERED

Herpesviruses can cause severe acute hepatitis, but little is known about the role and the mechanisms of herpesviruses as a causative agent of this type of hepatitis. We review the role of herpesviruses as causative agent of SAH in children and other possible mechanisms involved in this disease.

EXPERT OPINION

Differential diagnosis for herpesvirus in SAH should be implemented in all settings. Alternative fluids, such as saliva and dried blood, could be used in the diagnosis to overwhelm the availability of biological specimens at sufficient volume. In the future, genetic studies could also be added to increase the knowledge about severe acute hepatitis in children.

Combination of Plasma Exchange and Adsorption Versus Plasma Exchange in Pediatric Acute Liver Failure: A Multicenter Cohort Study

OBJECTIVES

This study aimed to compare the efficacy of double plasma molecular adsorption system (DPMAS) with half-dose plasma exchange (PE) to that of full-dose PE in pediatric acute liver failure (PALF).

METHODS

This multicenter, retrospective cohort study was conducted in 13 pediatric intensive care units in Shandong Province, China. DPMAS+PE and single PE therapies were performed in 28 and 50 cases, respectively. The patients' clinical information and biochemical data were obtained from the patients' medical records.

RESULTS

The severity of illness did not differ between the 2 groups. At 72 hours after treatment, comparing with PE group, the rates of decline of Pediatric model for End-stage Liver Disease and Pediatric Sequential Organ Failure Assessment scores as well as total bilirubin blood ammonia and interleukin-6 were significantly higher, while the short-term effective rate (75.0% vs 44.0%, P = 0.008) was significantly higher in the DPMAS+PE group. The volume of plasma consumption (26.5 vs 51.0 mL/kg, P = 0.000) and the rate of adverse events (3.6% vs 24.0%, P = 0.026) were lower in the DPMAS+PE group than in the PE group, respectively. However, there was no statistical difference in the 28-day mortality between the 2 groups (21.4% vs 40.0%, P > 0.05).

CONCLUSIONS

For PALF patients, both DPMAS + half-dose PE and full-dose PE could improve the liver function, while DPMAS + half-dose PE could significantly reduce plasma consumption without obvious adverse effects in contrast with full-dose PE. Thus, DPMAS + half-dose PE may be a suitable alternative method for PALF in the context of the increasingly tight blood supply situation.

Identifying the Aetiology of Acute Liver Failure Is Crucial to Impact Positively on Outcome

Management of children with acute liver failure is challenging. In this retrospective study, paediatric patients diagnosed with ALF at our centre, in the last 26 years, were divided into two groups (G1 = diagnosed from 1997 to 2009; G2 = from 2010 to 2022) and compared to see whether they differed with regard to aetiologies, need for liver transplantation (LT), and outcome. A total of 90 children (median age 4.6 years, range 1.2-10.4; M/F = 43/47) were diagnosed with ALF, by autoimmune hepatitis (AIH) in 16 (18%), paracetamol overdose in 10 (11%), Wilson disease in 8 (9%), and other causes in 19 (21%); 37 (41%) had indeterminate ALF (ID-ALF). Comparing the two periods, the clinical features, aetiologies, and median peak values of INR [3.8 (2.9-4.8) in G1 vs. 3.2 (2.4-4.8) in G2] were similar (p > 0.05). The percentage of ID-ALF tended to be higher in G1 compared to G2 (50% vs. 32% in G2, p = 0.09). The overall percentage of patients diagnosed with Wilson disease, inborn errors of metabolism, neonatal hemochromatosis or viral infection was higher in G2 (34% vs. 13% in G1, p = 0.02). A total of 21/90 patients (23%; 5 with indeterminate ALF) were treated with steroids; 12 (14%) required extracorporeal liver support treatment. The need for LT was significantly higher in G1 compared to G2 (56% vs. 34%; p = 0.032). Among 37 children with ID-ALF, 6 (16%) developed aplastic anaemia (all in G2, p < 0.001). The survival rate at last follow up was of 94%. On a KM curve, the transplant-free survival was lower in G1 compared to G2. In conclusion, we report a lower need for LT in children diagnosed with PALF during the most recent period compared to the first era. This suggests improvements over time in the diagnosis and management of children with PALF.

Acute hepatitis of unknown origin in children: A combination of factors

On 5 April 2022, the World Health Organization was notified of 10 cases of severe acute hepatitis of unknown etiology in children under 10 years of age in the United Kingdom. Although the exact cause of a proportion of pediatric acute hepatitis and acute liver failure cases was unclear, the above event has caused widespread concern worldwide. As of 14 September 2022, approximately 1,296 probable cases of acute hepatitis of unknown etiology have been reported from 37 countries/regions, of which approximately 55 required or received liver transplantation and 29 died. Although the etiology of acute hepatitis of unknown origin in children remains unclear, many hypotheses have been proposed about the disease. Instead of individual factors such as "adenovirus infection," "SARS-CoV-2 related," and "Adeno-associated virus 2 with helper virus coinfection," it is more likely due to a combination of factors. Accordingly, there is an urgent need for more data and research to clarify the disease etiology. This review aims to provide a historical perspective of acute hepatitis of unknown etiology in children in the past decades and summarize the current hypothesis and evidence on this emerging disease.

Hepatitis of unknown etiology in children: What we know and what we can do?

Recently, acute hepatitis of unknown etiology in children has gained great concern since March 2022. The disease was first reported by Public Health Scotland. Cases increased rapidly and are now reported in 33 countries worldwide. All cases are predominantly aged under 5 years old. Most patients presented with jaundice, and remarkably, some cases progress to acute liver failure. Until now, the etiology is not fully elucidated, and the investigations are ongoing. Adenovirus infection seems to be an important factor. Several hypotheses on the etiology have been proposed. This review aims to summarize current research progress and put forward some suggestions.

Proceedings of ESPGHAN Monothematic Conference 2020: "Acute Liver Failure in Children": Diagnosis and Initial Management

OBJECTIVES

The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology. Herewith we have concentrated on detailing the recent advances in acute liver failure in infants and children.

METHODS

The 2020 ESPGHAN monothematic three-day conference on pediatric hepatology disease, entitled "acute liver failure" (ALF), was organized in Athens, Greece. ALF is a devastating disease with high mortality and most cases remain undiagnosed. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with the latest research and developments in early recognition, curative therapies and intensive care management, imaging techniques and treatment paradigms in these age groups.

RESULTS

In the first session, the definition, epidemiology, various causes of ALF, in neonates and older children and recurrent ALF (RALF) were discussed. The second session was dedicated to new aspects of ALF management including hepatic encephalopathy (HE), coagulopathy, intensive care interventions, acute on chronic liver failure, and the role of imaging in treatment and prognosis. Oral presentations by experts in various fields are summarized highlighting key learning points.

CONCLUSIONS

The current report summarizes the major learning points from this meeting. It also identifies areas where there is gap of knowledge, thereby identifying the research agenda for the near future.

Proceedings of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition Monothematic Conference, 2020: "Acute Liver Failure in Children": Treatment and Directions for Future Research

OBJECTIVES

The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology.

METHODS

The 2020 single topic ESPGHAN monothematic 3-day conference on pediatric liver disease, was organized in Athens, Greece and was entitled " Acute Liver Failure" (ALF). ALF is a devastating disease with high mortality and in a considerable fraction of patients, the cause remains unresolved. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with developments in medical therapy and indications for liver transplantation (LT) and to identify areas for future research in clinical and neurocognitive outcomes in ALF.

RESULTS

We recently reported the epidemiology, diagnosis, and initial intensive care management issues in separate manuscript. Herewith we report on the medical treatment, clinical lessons arising from pediatric studies, nutritional and renal replacement therapy (RRT), indications and contraindications for LT, neurocognitive outcomes, new techniques used as bridging to LT, and areas for future research. Oral presentations by experts in various fields are summarized highlighting key learning points.

CONCLUSIONS

The current report summarizes the current insights in medical treatment of pediatric ALF and the directions for future research.

The Role of Predictive Models in the Assessment of the Poor Outcomes in Pediatric Acute Liver Failure

OBJECTIVES

In children, acute liver failure (ALF) is a severe condition with high mortality. As some patients need liver transplantation (LT), it is essential to predict the fatal evolution and to refer them early for LT if needed. Our study aimed to evaluate the prognostic criteria and scores for assessing the outcome in children with ALF.

METHODS

Data of 161 children with ALF (54.66% female, mean age 7.66 ± 6.18 years) were analyzed based on final evolution (32.91% with fatal evolution or LT) and etiology. We calculated on the first day of hospitalization the PELD score (109 children), MELD, and MELD-Na score (52 children), and King's College Criteria (KCC) for all patients. The Nazer prognostic index and Wilson index for predicting mortality were calculated for nine patients with ALF in Wilson's disease (WD).

RESULTS

PELD, MELD, and MELD-Na scores were significantly higher in patients with fatal evolution (21.04 ± 13.28 vs. 13.99 ± 10.07, p = 0.0023; 36.20 ± 19.51 vs. 20.08 ± 8.57, p < 0.0001; and 33.07 ± 8.29 vs. 20.08 ± 8.47, p < 0.0001, respectively). Moreover, age, bilirubin, albumin, INR, and hemoglobin significantly differed in children with fatal evolution. Function to etiology, PELD, MELD, MELD-Na, and KCC accurately predicted fatal evolution in toxic ALF (25.33 vs. 9.90, p = 0.0032; 37.29 vs. 18.79, p < 0.0001; 34.29 vs. 19.24, p = 0.0002, respectively; with positive predicting value 100%, negative predicting value 88.52%, and accuracy 89.23% for King's College criteria). The Wilson index for predicting mortality had an excellent predictive strength (100% sensibility and specificity), better than the Nazer prognostic index.

CONCLUSIONS

Prognostic scores may be used to predict the fatal evolution of ALF in children in correlation with other parameters or criteria. Early estimation of the outcome of ALF is essential, mainly in countries where emergency LT is problematic, as the transfer to a specialized center could be delayed, affecting survival chances.

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.

Diagnostic Approach to Acute Liver Failure in Children: A Position Paper by the SIGENP Liver Disease Working Group

Acute liver failure (ALF) is a clinical condition characterized by the abrupt onset of coagulopathy and biochemical evidence of hepatocellular injury, leading to rapid deterioration of liver cell function. In children, ALF has been characterized by raised transaminases, coagulopathy, and no known evidence of pre-existing chronic liver disease; unlike in adults, the presence of hepatic encephalopathy is not required to establish the diagnosis. Although rare, ALF has a high mortality rate without liver transplantation (LT). Etiology of ALF varies with age and geographical location, although it may remain indeterminate in a significant proportion of cases. However, identifying its etiology is crucial to undertake disease-specific management and evaluate indication to LT. In this position statement, the Liver Disease Working Group of the Italian Society of Gastroenterology, Hepatology and Nutrition (SIGENP) reviewed the most relevant studies on pediatric ALF to provide recommendations on etiology, clinical features and diagnostic work-up of neonates, infants and children presenting with ALF. Recommendations on medical management and transplant candidacy will be discussed in a following consensus conference.

Acute liver failure in newborns

Acute liver failure is a condition that is defined as a sudden, complete, or nearly complete loss of liver functions without any previous liver disease, usually accompanied by encephalopathy, which can be reversible, but with a mortality rate of 55-70%. Acute liver failure newborns is an acute liver failure in the first 28 days of life. The Pediatric Acute Liver Failure Working Group identified the presence of coagulopathy as the main finding for the identification of acute liver failure in childhood following vitamin K administration. Although the incidence of acute liver failure is reported to be 17/100 000 in all ages, its incidence is not known exactly in newborn and childhood. The most common cause of acute liver failure in the newborn period is the gestational alloimmune liver disease that was previously known as neonatal hemochromatosis. This is followed by viral infections, metabolic diseases, hemophagocytic lymphohistiocytosis, and other rare causes. In the neonatal period, acute liver failure is a rare condition with a high mortality rate. For this reason, the vital signs of the patients should be closely monitored and supportive treatments should be planned according to the follow-up and the etiology of the disease should be clarified urgently. In this process, acyclovir treatment until herpes simplex virus infection is excluded and lactose-free feeding until galactosemia is excluded are recommended as life-saving treatments. In the literature, since there is a limited number of studies related to neonatal acute liver failure, prospective studies investigating the factors affecting treatment and prognosis are needed.

Etiology and Outcome of Acute Liver Failure in Children-The Experience of a Single Tertiary Care Hospital from Romania

BACKGROUND

Acute liver failure (ALF) is a rare disease, associated with high mortality, despite optimal medical therapy without emergency liver transplantation. Knowing the possible cause of ALF plays a vital role in the management, as the child could benefit from effective specific therapies in emergencies.

METHODS

We have analyzed the etiology and outcome of ALF in children followed-up in a tertiary care hospital between January 2012-December 2018. The patients were grouped into different age categories: neonates (0-1 month), infants (1-12 months), children (1-14 years), and teenagers (14-18 years).

RESULTS

97 children (46 males, 47.42%, the mean age of 7.66 ± 8.18 years) were admitted with ALF. The most important causes of ALF were in neonates and infants, infections (72.72%), and metabolic disorders (43.47%), in children and adolescents were the toxic causes (60% and 79.41%). The mortality rate was 31.95% (31 patients), mainly in ALF due to infections or metabolic disorders.

CONCLUSIONS

In neonates and infants, the main causes of ALF were infections and metabolic diseases, while in older children and teenagers, were toxin-induced liver injuries. The mortality among neonates and infants was significantly higher than in other ages. Early recognition and immediate therapeutic intervention could improve the outcome of these patients.

Vitamin D-Binding Protein (Gc-Globulin) in Acute Liver Failure in Children

This study aimed to analyse vitamin d-binding protein (Gc-globulin) serum levels in acute liver failure (ALF) in children in relation to disease outcomes and correlations with other known markers used to evaluate the severity of ALF. Our study included 34 children (mean age 4.87 ± 5.30 years) with ALF of different causes (metabolic, 26.47%; autoimmune, 23.53%; toxic, 20.59%; infection, 17.65%; unknown, 11.76%) and 30 children without any liver injury (mean age 6.11 ± 4.26 years). The outcome was poor in 14 patients (41.18%), including one child with liver transplantation (2.94%). Serum Gc-globulin levels were significantly lower in ALF patients compared to the control group (151.57 ± 171.8 mg/L vs. 498.63 ± 252.50 mg/L; p < 0.000001), with an optimum cut-off of 163.5 mg/L (Area Under the Curve, AUC, 0.8921; sensitivity, 76.50%; specificity, 100%). Levels were also lower in patients with poor outcomes compared to survivors (59.34 ± 33.73 mg/L vs. 216.12 ± 199.69 mg/L; p < 0.0001), with an optimum cut-off 115 mg/L (AUC, 0.7642; sensitivity, 100%; specificity, 50%). Gc-globulin serum levels were variable according to ALF aetiology, i.e., lower in metabolic, infectious, or unknown causes compared to autoimmune and toxic causes. Gc-globulin serum levels were decreased in children with ALF and lower in those with poor outcomes compared with survivors. Gc-globulin serum levels were correlated with other known parameters used to evaluate the severity of ALF and could help to identify patients at high risk for poor outcomes.

Alginate microencapsulated human hepatocytes for the treatment of acute liver failure in children

BACKGROUND & AIMS

Liver transplantation (LT) is the most effective treatment for patients with acute liver failure (ALF), but is limited by surgical risks and the need for life-long immunosuppression. Transplantation of microencapsulated human hepatocytes in alginate is an attractive option over whole liver replacement. The safety and efficacy of hepatocyte microbead transplantation have been shown in animal models. We report our experience of this therapy in children with ALF treated on a named-patient basis.

METHODS

Clinical grade human hepatocyte microbeads (HMBs) and empty microbeads were tested in immunocompetent healthy rats. Subsequently, 8 children with ALF, who were awaiting a suitable allograft for LT, received intraperitoneal transplantation of HMBs. We monitored complications of the procedure, assessing the host immune response and residual function of the retrieved HMBs, either after spontaneous native liver regeneration or at the time of LT.

RESULTS

Intraperitoneal transplantation of HMBs in healthy rats was safe and preserved synthetic and detoxification functions, without the need for immunosuppression. Subsequently, 8 children with ALF received HMBs (4 neonatal haemochromatosis, 2 viral infections and 2 children with unknown cause at time of infusion) at a median age of 14.5 days, range 1 day to 6 years. The procedure was well tolerated without complications. Of the 8 children, 4 avoided LT while 3 were successfully bridged to LT following the intervention. HMBs retrieved after infusions (at the time of LT) were structurally intact, free of host cell adherence and contained viable hepatocytes with preserved functions.

CONCLUSION

The results demonstrate the feasibility and safety of an HMB infusion in children with ALF.

LAY SUMMARY

Acute liver failure in children is a rare but devastating condition. Liver transplantation is the most effective treatment, but it has several important limitations. Liver cell (hepatocyte) transplantation is an attractive option, as many patients only require short-term liver support while their own liver recovers. Human hepatocytes encapsulated in alginate beads can perform the functions of the liver while alginate coating protects the cells from immune attack. Herein, we demonstrated that transplantation of these beads was safe and feasible in children with acute liver failure.

Acute onset of autoimmune hepatitis in children and adolescents

BACKGROUND

Autoimmune hepatitis (AIH) is a rare progressive liver disease, which manifests as acute hepatitis in 40%-50% of pediatric cases. This refers predominantly to spontaneous exacerbations of previously unrecognized subclinical AIH with laboratory and histological signs of chronic hepatitis, or to acute exacerbations of known chronic disease. Only a few of these patients fulfill criteria for acute liver failure (ALF).

METHODS

Forty children diagnosed with AIH in our center between 2000 and 2018 were included in this study. All of them fulfilled revised diagnostic criteria of the International Autoimmune Hepatitis Group (IAIHG) for probable or confirmed AIH, and other etiologies of liver diseases were excluded. Patients were divided into two groups: acute AIH (A-AIH) or chronic AIH (C-AIH).

RESULTS

Acute onset of AIH occurred in 19/40 children (48%). Six of them fulfilled the criteria of ALF with coagulopathy and encephalopathy. Five of 6 children with ALF suffered from exacerbation of previously undiagnosed chronic AIH, among which 4 children were histologically confirmed as micronodular cirrhosis. The remaining one patient had fulminant AIH with centrilobular necrosis, but no histological signs of previous chronic liver damage. We observed significantly lower levels of albumin, higher levels of aminotransferases, bilirubin, INR, IgG, higher IAIHG score and more severe histological findings in A-AIH than in C-AIH. No differences in patient age and presence of autoantibodies were observed between A-AIH and C-AIH. All children, including those with ALF and cirrhosis, were treated with corticosteroids, and are alive and achieved AIH remission. Liver transplant was not indicated in any patient.

CONCLUSION

Rapid and accurate diagnosis of A-AIH may be difficult. However, timely start of immunosuppressive therapy improves prognosis and decreases number of indicated liver transplantations in children with AIH.

Transplant-free Survival in Chronic Liver Disease Presenting as Acute Liver Failure in Childhood

BACKGROUND

In adults, the absence of a preexisting chronic liver disease (CLD) is required to diagnose acute liver failure (ALF). The pediatric classification does not consider this aspect, thus previous studies pooled together children with ALF and children with unknown CLD presenting with acute hepatic decompensation (ALF-CLD). We aimed to compare prevalence, features, and outcome of children with ALF-CLD to those with a proper ALF.

METHODS

Patients admitted between 1996 and 2017 because of ALF defined by Pediatric Acute Liver Failure criteria (raised transaminases, International Normal Ratio ≥2.0, no history of liver disease) were classified as ALF-CLD if diagnosed with autoimmune hepatitis, Wilson disease, Budd-Chiari syndrome, hepatitis B virus reactivation, inborn errors of metabolism. The others were classified as ALF.

RESULTS

Seventy-four children (median age, 4 years; 1.0-8.8; male/female, 36/38] with ALF were found; 18 of <1 year of age were excluded. Fifty-six (median age, 6.6 years; 2.7-11.7; male/female, 23/33], 22 with ALF-CLD (autoimmune hepatitis, n = 14; Wilson disease, n = 6; inborn errors of metabolism, n = 2) and 34 with ALF (paracetamol overdose, n = 6; viral infections, n = 3; mushroom poisoning, n = 5; indeterminate, n = 20) were compared. In ALF-CLD, the median age at onset was higher, alanine aminotransferase, albumin, and International Normal Ratio levels were lower, splenomegaly, ascites, and cirrhosis were more common (all P < 0.01). On multivariate analysis, the diagnosis of ALF-CLD was an independent predictor of transplant-free survival (P = 0.006).

CONCLUSIONS

In children, ALF-CLD is common, has peculiar features, and is associated with a favorable outcome. This study suggests the need to distinguish this entity from other forms of ALF in children.

Fulminant acute hepatitis in pediatrics in Latin America and the Caribbean

SUMMARY OBJECTIVE: The objective of this review was to investigate the epidemiology of Fulminant Acute Hepatitis in Latin America and the Caribbean and identify possible measures aimed at a better understanding and improvement of patient support. METHODS: We used 3 different researchers to investigate the topic of Fulminant Acute Hepatitis in pediatrics in papers published by Latin American and Caribbean authors in the PubMed and SciELO databases from 2000 to 2016. RESULTS: We found 2,879 articles in the databases searched. After selecting and excluding articles according to the study protocol, 68 remaining studies were obtained for analysis. A total of 1,265 cases of acute fulminant hepatitis were detected, with a predominance of females (42.9%), followed by males (39.4%), with no description of sex in 17.7% of the cases. The main cause was viral hepatitis, representing 45.1% of the cases. The hepatitis A virus was responsible for 34.7% of the total cases and 76.9% of the infectious causes. Of the total number of patients, 26.9% were described as idiopathic, and 11.5% had no cause. CONCLUSION: The preventable causes of Fulminant Acute Hepatitis include hepatitis viruses - primarily the hepatitis A virus - and poisoning. Active vaccination, basic sanitation, and public awareness can reduce the number of patients and, consequently, the costs of liver transplantation due to these causes.

Successful management of acute liver failure in Italian children: A 16-year experience at a referral centre for paediatric liver transplantation

BACKGROUND

Identifying the causes of acute liver failure (ALF) and predictors of death or liver transplantation (LTX) is crucial to decide its management. We aimed to describe features and outcome of ALF in Italian children.

METHODS

Retrospective review of cases presenting between 1996-2012. ALF was defined by high transaminases, INR ≥2.0 regardless of hepatic encephalopathy (HE), no evidence of underlying chronic liver disease.

RESULTS

55 children (median age 2.6 years, range 0.1-15.1; M/F=31/24) had ALF due to autoimmune hepatitis (AIH) in 10 (18%), metabolic disorders in 9 (17%), paracetamol overdose in 6 (11%), mushroom poisoning in 3 (5%), viral infection in 1 (2%), indeterminate in 26 (47%); 25/55 recovered with supportive management (45%); 28/55 underwent LTX and 2 died on the waiting list (55%). On multivariate analysis severity of HE grade 3-4 and bilirubin ≥12mg/dl were independent predictors of death or LTX (p<0.05). After a median follow up of 4 years (range 2-15.0 years) the overall survival rate was 93%.

CONCLUSION

Children with ALF can be managed successfully with combined medical treatment and transplantation, warranting a survival rate similar to children transplanted because of chronic conditions. In our cohort of patients severe HE and high bilirubin on admission were independent predictors of the need of LTX.

NBAS mutations cause acute liver failure: when acetaminophen is not a culprit

Background

Pediatric acute-liver-failure due to acetaminophen (APAP) administration at therapeutic dosage is rare, while viral infections and metabolic defects are the prevalent causes. Yet, as acetaminophen is routinely used in febrile illnesses, it may be mistakenly held responsible for the acute liver damage.

Case presentation

An 11 month old boy had been on acetaminophen for 10 days (total dose 720 mg = 72 mg/kg) when he developed acute-liver-failure with encephalopathy. As he rapidly improved on N-acetylcysteine (NAC) infusion, it was concluded that chronic acetaminophen administration in an infant had lead to acute-liver-failure even at therapeutic doses, that N-acetylcysteine infusion had been life-saving and should be immediately started in similar circumstances. The child, however, had two further episodes of acute liver damage over a 34-month period, without having been given acetaminophen, as the parents carefully avoided using it. His clinical, laboratory and radiological findings between the acute episodes were unremarkable. His features and skeletal surveys were not suggestive of a syndromic condition. He then went on to suffer another episode of acute-liver-failure with multi-organ failure, necessitating an urgent liver transplant. All efforts to come to a diagnosis for the causes of his recurrent episodes of liver failure had been unsuccessful, until a biallelic mutation in the NBAS gene was reported to be associated with recurrent acute-liver-failure in children. The boy’s DNA analysis revealed compound heterozygous pathogenic mutations in the NBAS gene. Liver failure episodes in these patients are triggered and worsened by fever, most likely due to thermal susceptibility of hepatocytes, hence APAP, rather than being a culprit, is part of the supportive treatment.

Conclusions

We suggest that, in acute-liver-failure with a history of acetaminophen exposure at therapeutic dosage, clinicians should not be contented with administering NAC, but should consider an alternative etiology, above all if the episodes are recurrent, and actively start supportive and antipyretic treatment while seeking the advice of a specialist unit.

Acute liver dysfunction not resulting from hepatitis virus in immunocompetent children

BACKGROUND

The aim of the present study was to clarify the roles of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6) in immunocompetent children with acute liver dysfunction not resulting from hepatitis virus.

METHODS

Sixty-eight children (median age, 3 years) hospitalized as a result of acute liver dysfunction were enrolled in this study. Hepatitis A, B, and C were excluded. The prevalence of CMV, EBV, and HHV-6 and viral DNA load in whole blood was prospectively evaluated on multiplex real-time polymerase chain reaction (PCR).

RESULTS

Of the 68 children with acute liver dysfunction, multiplex real-time PCR was positive in 30 (44%). CMV, EBV, and HHV-6 DNA were detected in 13 (19%), 14 (21%), and seven (10%), respectively. Serum CMV immunoglobulin (Ig)G/IgM and EBV viral capsid antigen IgG/IgM were measured in 40 (CMV DNA positive, n = 10; negative, n = 30) and 45 (EBV DNA positive, n = 14; negative, n = 31) of the 68 children, respectively. Eighteen percent (CMV, 7/40) and 9% (EBV, 4/45) were positive for both PCR and viral-specific IgM. There was no significant difference in CMV and EBV viral load between IgM-positive and -negative children with viremia.

CONCLUSIONS

CMV, EBV, and HHV-6 DNA were frequently detected in immunocompetent children with acute liver dysfunction, but primary CMV and EBV infection were confirmed in 10-20% of the children with acute liver dysfunction. The combination of PCR assay and serology is necessary to make a diagnosis of acute liver dysfunction due to primary CMV, EBV and/or HHV-6 infection in immunocompetent children.

Liver Failure in Early Infancy: Aetiology, Presentation, and Outcome

OBJECTIVE

Acute liver failure (ALF) in early infancy is rare and challenging to recognize and manage. We aim to describe the presentation and outcome of infants with ALF according to their final aetiology to elucidate features to facilitate early recognition leading to prompt diagnosis and management.

METHODS

All infants presenting within 120 days from birth with liver failure were included in a retrospective review over a 19-year period. The aetiology, clinical features, presenting investigations, and outcome were collected.

RESULTS

Seventy-eight young infants presented with ALF. The aetiology was established in 94% and included metabolic disease (36%), hypoxic-ischaemic (HI) insult (19%), infection (17%), neonatal haemochromatosis (9%), and infiltrative disease (9%). Infections, infiltrative disease, and acute HI insult usually resulted in higher transaminases and international normalized ratio, whereas neonatal haemochromatosis and tyrosinaemia were characterized by lower or near normal transaminases. Overall jaundice was not visible in 24% of infants at presentation. Forty-five (58%) infants were alive at discharge from hospital. Survival at 1 year was 53% and survival with native liver 50%. Later deaths occurred in infants with mitochondrial disease. Six infants received a liver transplant and 4 subsequently died from their underlying disease.

CONCLUSION

ALF should be considered in any young infant with a coagulopathy as transaminases and/or bilirubin levels can be near normal at presentation. Better intensive care and the judicious use of liver transplantation may have contributed to the improved outcomes for this group compared with previous decades.

Prognostic modeling in pediatric acute liver failure

Liver transplantation (LT) is the only proven treatment for pediatric acute liver failure (PALF). However, over a period of time, spontaneous native liver survival is increasingly reported, making us wonder if we are overtransplanting children with acute liver failure (ALF). An effective prognostic model for PALF would help direct appropriate organ allocation. Only patients who would die would undergo LT, and those who would spontaneously recover would avoid unnecessary LT. Deriving and validating such a model for PALF, however, encompasses numerous challenges. In particular, the heterogeneity of age and etiology in PALF, as well as a lack of understanding of the natural history of the disease, contributed by the availability of LT has led to difficulties in prognostic model development. Several prognostic laboratory variables have been identified, and the incorporation of these variables into scoring systems has been attempted. A reliable targeted prognostic model for ALF in Wilson's disease has been established and externally validated. The roles of physiological, immunological, and metabolomic parameters in prognosis are being investigated. This review discusses the challenges with prognostic modeling in PALF and describes predictive methods that are currently available and in development for the future. Liver Transplantation 22 1418-1430 2016 AASLD.

A conceptual and practical approach to haemostasis in paediatric liver disease

Children with liver disease can develop severe bleeding episodes and thrombosis. Liver failure usually results in decreased levels of procoagulant and anticoagulant factors. Additional risk factors, including changes in vascular flow and endothelial function, are of importance for the development of bleeding or thrombosis in individual vascular beds. Detailed studies of haemostatic disturbances in the setting of paediatric liver disease are sparse and extrapolation from adult studies is common. The spectrum of liver diseases and the haemostatic system differs between children and adults. Specific paediatric liver diseases are reported to have more distinctive effects on haemostasis and the risk of bleeding and/or thrombosis.

CONCLUSION

we propose a model regarding haemostasis in paediatric liver disease, taking into account a number of specific variables and mechanisms, as well as the type of liver disease, which will provide a framework for clinical decision-making in these complex patients.

Pediatric acute liver failure in Brazil: Is living donor liver transplantation the best choice for treatment?

Acute liver failure (ALF) in children is a life-threatening condition that often leads to urgent liver transplantation (LT). The aim of the present investigation was to describe the experience in Brazil in treating pediatric ALF, with an emphasis on the role of living donor liver transplantation (LDLT) in treating this condition. All children with ALF who fulfilled the criteria for an urgent LT were admitted to the intensive care unit. Patients were divided into 2 groups based on the moment of admission: before and after June 2007, when the LDLT program for ALF was started. Statistical analyses were performed to identify prognostic factors of patients with ALF. For the study, 115 children with ALF were admitted. All patients had some degree of encephalopathy. Among the patients, 26% of them required intracranial pressure monitoring (IPM), 12.8% of the patients required hemodialysis, and 79 patients underwent transplantation (50 deceased donors and 29 living donors) corresponding to 12.4% of all pediatric LTs. Only 9 children recovered without LT. The need for IPM and nonperformance of LT were related to a higher mortality. The mortality rate of patients who underwent LT was significantly lower than that of children with ALF who did not undergo a LT (48.1% versus 75%; P = 0.02). The incidences of primary nonfunction and mortality were statistically higher among deceased donor liver transplantations than LDLTs. Finally, it was verified that the overall survival rate of transplanted patients was increased after the introduction of LDLT (P = 0.02). In conclusion, ALF in children continues to be a severe and devastating condition, and a LT should be performed promptly. The introduction of LDLT could increase the survival rate of patients in Brazil. Liver Transplantation 22 1006-1013 2016 AASLD.

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.

High-volume hemofiltration in children with acute liver failure*

OBJECTIVES

High-volume hemofiltration has shown beneficial effects in severe sepsis and multiple organ failure, improving hemodynamics and fluid balance. Recent studies suggest that acute liver failure shares many pathophysiologic similarities with sepsis. Therefore, we assessed the systemic effects of high-volume hemofiltration in children with acute liver failure.

DESIGN

Retrospective observational cohort study.

PATIENTS

Twenty-two children.

SETTING

Forty-two-bed multidisciplinary pediatric and neonatal ICUs in a tertiary university hospital.

INTERVENTION

We evaluated high-volume hemofiltration therapy as part of standard management of 22 children admitted in our unit for acute liver failure. Fifteen patients had fulminant hepatic failure, three had acute-on-chronic liver disease, and four had primary nonfunction. High-volume hemofiltration was initiated in patients requiring emergency liver transplantation and when hepatic encephalopathy grade higher than 2 and/or hemodynamic instability requiring vasopressors occurred. High-volume hemofiltration was defined by a flow of ultrafiltrate of more than 80 mL/kg/hr. Clinical and biological variables were assessed before and 24 and 48 hours after initiation of high-volume hemofiltration therapy.

MEASUREMENTS AND MAIN RESULTS

High-volume hemofiltration was initiated with a median grade III of hepatic encephalopathy. The median flow of ultrafiltrate was 119 mL/kg/hr (range, 80-384). After 24 hours of high-volume hemofiltration treatment, we observed an increase in mean arterial pressure (p = 0.0002) and a decrease in serum creatinine (p = 0.0002). In half of the patients, the encephalopathy grade decreased. After 48 hours of treatment, mean arterial pressure (p = 0.0005), grade of hepatic encephalopathy (p = 0.04), and serum creatinine (p = 0.0002) improved. Overall mortality was 45.4% (n = 10). Emergency liver transplantation was performed in eight children. Five patients spontaneously recovered liver function.

CONCLUSIONS

High-volume hemofiltration therapy significantly improves hemodynamic stability and neurological status in children with acute liver failure awaiting for emergency liver transplantation.

Molecular Absorbent Recirculating System therapy (MARS®) in pediatric acute liver failure: a single center experience

BACKGROUND

Supportive care as a bridge to transplant or recovery remains challenging in children suffering from acute liver failure (ALF). We report our experience in children using the Molecular Absorbent Recirculating System (MARS(®)).

METHODS

Retrospective data from children receiving therapy using MARS(®) from October 2009 to October 2012 were included in this single-center retrospective study. Patient characteristics, clinical presentation and complications of ALF, clinical and biological data before and after each MARS(®) session, technical modalities and adverse events were recorded.

RESULTS

A total of six children underwent 17 MARS(®) sessions during the study period. Two adolescents were treated with the adult filter MARSFLUX(®) and four infants were treated with the MiniMARS(®) filter. The mean PEdiatric Logistic Dysfunction (PELOD) score at admission was 19 (range 11-33). All patients were mechanically ventilated, and four had acute kidney injury. The neurological course improved in one case, judged as stable in two cases and worsened in one case; data were unavailable in two cases. Mean serum ammonia levels decreased significantly following treatment with MARS(®) from an initial 89 ± 29 to 58 ± 35 mcmol/L (p = 0.02). No other significant biological improvement was observed. Hemodynamic status improved/remained unchanged in the adolescent group, but in the infants four of the seven sessions were poorly tolerated and two sessions were aborted. Three patients died, two were successfully transplanted and one recovered without transplantation.

CONCLUSION

In our experience, treatment with MARS(®) is associated with encouraging results in adolescents, but it needs modification for very sick infants to improve tolerance.

Can experience from adults regarding acute liver failure fit children?

Till date, comparison of clinical characteristics in acute liver failure (ALF) between adults and children has not been performed. In this study, authors retrospectively collected data on adult acute liver failure (AALF) and pediatric acute liver failure (PALF) in seven hospitals in different areas of China from January 2007 through December 2012. A total of 177 AALF cases and 32 PALF cases were eventually included. Several vital clinical variables were significantly different between AALF and PALF, including serum alkaline phosphatase, serum creatinine, serum urea nitrogen, serum lactate dehydrogenase, platelet count, prothrombin activity, international normalized ratio and blood ammonia. It is concluded that experience from AALF could not be proper for PALF.

Pediatric liver transplantation: where do we stand? Where we are going to?

Pediatric liver transplantation (LT) is one of the most successful solid organ transplants with long-term survival more than 80%. Many aspects have contributed to improve survival, especially advancements in pre-, peri- and post-transplant management. The development of new surgical techniques, such as split-LT and the introduction of living related LT, has extended LT to small infants. Progress in the last 30 years has also been characterized by the introduction of calcineurin inhibitors. One problem remains the lack of donors. Donation after cardiac death offers a new possibility to increase the pool of potential donors. In children with acute liver failure, increasing interest has centered on the possibility of providing temporary liver support based on extracorporeal devices or hepatocyte transplantation. Similarly, hepatocyte transplantation offers new perspective in children with metabolic failure. As long-term survival increases, attention has now focused on the quality of life achieved by children undergoing LT.

Management and prognosis of acute liver failure in children

Although the etiologies of pediatric acute liver failure (ALF) are diverse, ultimate pathophysiologic pathways and management challenges for these disorders, usually lethal in the pre-transplant era, are similar. This review considers particularly the mechanisms of, and monitoring for, intracranial hypertension and coagulopathy; summarizes detailed advice for management of the ALF-associated failures of multiple body systems; and reviews the variety of prognostic scores available to guide management and assist in choosing the patients most apt to benefit from liver transplantation and the optimal timing for such transplantation.

Acute liver failure in neonates, infants and children

Acute liver failure (ALF) is a rare but devastating syndrome. ALF in children differs from that observed in adults in both the etiologic spectrum and the clinical picture. Specific therapy to promote liver recovery is often not available and the underlying cause of the liver failure is often not determined. Management requires a multidisciplinary approach and should focus on preventing or treating complications and arranging for early referral to a transplant center. Although liver transplantation has increased the chance of survival, children who have ALF still face an increased risk of death, both while on the waiting list and after emergency liver transplantation. This article will review the current knowledge of the epidemiology, pathobiology and treatment of ALF in neonates, infants and children, and discuss some recent controversies.