Acute liver failure.

ABSTRACT: Acute liver failure, commonly caused by acetaminophen overdose, is associated with numerous systemic complications including cerebral edema, hypotension, acute kidney injury, and infection. Management is primarily supportive, with an emphasis on excellent neurocritical care. Although some antidotes and targeted treatments exist, the only definitive treatment remains orthotopic liver transplant.

[Advancements in the diagnosis and treatment of pediatric acute liver failure]. / 儿童急性肝衰竭的诊治进展.

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.

Unconjugated Hyperbilirubinemia in Acetaminophen-Related Acute Liver Failure.

BACKGROUND In the absence of liver transplantation, the natural history of acetaminophen-induced liver failure is characterized by a progressive increase of liver function tests, including bilirubin mainly as its conjugated form. The presence of high levels of unconjugated bilirubin is more unusual; its etiology is unclear and its prognostic factor has been poorly investigated. CASE REPORT A 52-year-old man with a history of chronic analgesics, alcohol, and illicit drug abuse developed acute liver failure in relationship with the ingestion of largely supra-therapeutic doses of acetaminophen over the days preceding admission. The patient received the classical N-acetylcysteine treatment regimen for acetaminophen overdose. Clinical course was characterized by a progressive worsening of the neurological condition, evolving to grade IV encephalopathy. Coagulation disorders persisted, with factor V level <10%. He fulfilled the criteria for liver transplantation, but this option was rejected after a careful psychiatric evaluation. Laboratory investigations revealed a progressive increase in serum unconjugated bilirubin until his death. As evidence for hemolysis was lacking, acquired deficit in bilirubin glucuronidation appeared likely and diagnosis of Gilbert's syndrome was excluded. CONCLUSIONS After the exclusion of other causes of high unconjugated bilirubin levels, the progressive increase in unconjugated bilirubin can reflect a persistent defect in bilirubin conjugation in relationship with liver centrilobular injury, but the relationship with acetaminophen-glucuronidation is not known and there are insufficient data to affirm that the ratio unconjugated/conjugated bilirubin could be used as a prognostic factor.

Improved mortality prediction for pediatric acute liver failure using dynamic prediction strategy.

OBJECTIVES: To develop and validate a prediction tool for pediatric acute liver failure (PALF) mortality risks that captures the rapid and heterogeneous clinical course for accurate and updated prediction. METHODS: Data included 1144 participants with PALF enrolled during three phases of the PALF registry study over 15 years. Using joint modeling, we built a dynamic prediction tool for mortality by combining longitudinal trajectories of multiple laboratory and clinical variables. The predictive performance for 7-day and 21-day mortality was assessed using the area under curve (AUC) through cross-validation and split-by-time validation. RESULTS: We constructed a prognostic joint model that combines the temporal trajectories of international normalized ratio, total bilirubin, hepatic encephalopathy, platelet count, and serum creatinine. Dynamic prediction using updated information improved predictive performance over static prediction using the information at enrollment (Day 0) only. In cross-validation, AUC increased from 0.784 to 0.887 when measurements obtained between Days 1 and 2 were incorporated. AUC remained similar when we used the earlier subset of the sample for training and the later subset for testing. CONCLUSIONS: Serial measurements of five variables in the first few days of PALF capture the dynamic clinical course of the disease and improve risk prediction for mortality. Continuous disease monitoring and updating risk prognosis are beneficial for timely and judicious medical decisions.

'Double whammy': An Unusual Co-occurrence of Idiosyncratic phenytoin-induced agranulocytosis and acute liver failure in a child.

Idiosyncratic adverse events to phenytoin therapy, such as agranulocytosis and acute liver failure, though rare, may be life-threatening. Simultaneous occurrence of both adverse events is exceedingly rare; only two cases have been reported in the literature to date. We describe such a case in a 15-year-old girl. Prompt haematological and hepatic recovery occurred after discontinuation of the drug. Given the widespread use of phenytoin in seizure disorders, clinicians prescribing this drug should be aware of its potential complications. Early recognition can considerably improve outcomes.

Genetic landscape of pediatric acute liver failure of indeterminate origin.

BACKGROUND AND AIMS: Pediatric acute liver failure (PALF) is a life-threatening condition. In Europe, the main causes are viral infections (12%-16%) and inherited metabolic diseases (14%-28%). Yet, in up to 50% of cases the underlying etiology remains elusive, challenging clinical management, including liver transplantation. We systematically studied indeterminate PALF cases referred for genetic evaluation by whole-exome sequencing (WES), and analyzed phenotypic and biochemical markers, and the diagnostic yield of WES in this condition. APPROACH AND RESULTS: With this international, multicenter observational study, patients (0-18 y) with indeterminate PALF were analyzed by WES. Data on the clinical and biochemical phenotype were retrieved and systematically analyzed. RESULTS: In total, 260 indeterminate PALF patients from 19 countries were recruited between 2011 and 2022, of whom 59 had recurrent PALF. WES established a genetic diagnosis in 37% of cases (97/260). Diagnostic yield was highest in children with PALF in the first year of life (41%), and in children with recurrent acute liver failure (64%). Thirty-six distinct disease genes were identified. Defects in NBAS (n=20), MPV17 (n=8), and DGUOK (n=7) were the most frequent findings. When categorizing, the most frequent were mitochondrial diseases (45%), disorders of vesicular trafficking (28%), and cytosolic aminoacyl-tRNA synthetase deficiencies (10%). One-third of patients had a fatal outcome. Fifty-six patients received liver transplantation. CONCLUSIONS: This study elucidates a large contribution of genetic causes in PALF of indeterminate origin with an increasing spectrum of disease entities. The high proportion of diagnosed cases and potential treatment implications argue for exome or in future rapid genome sequencing in PALF diagnostics.

A retrospective study to evaluate Hy's Law, DrILTox ALF score, Robles-Diaz model, and a new logistic regression model for predicting acute liver failure in Chinese patients with drug-induced liver injury.

OBJECTIVES: To evaluate Hy's law, DrILTox ALF Score, Robles-Diaz Model, and a new logistic regression model for predicting acute liver failure (ALF) in Chinese patients with drug-induced liver injury (DILI). METHODS: We conducted a retrospective study among 514 hospitalized DILI patients from 2011 to 2020. Logistic regression analysis was used to develop a predictive model for ALF. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these models were compared. Another 304 DILI patients were used for external validation. OUTCOMES: Twenty-six of 514 DILI patients progressed to ALF. Among these models, Hy's law had 84.6% sensitivity, 59.8% specificity, 10.1% PPV, and 98.6% NPV. DrILTox ALF Score had 92.3% sensitivity, 51.8% specificity, 9.3% PPV, and 99.2% NPV, while Robles-Diaz Model had 50.0% sensitivity, 77.7% specificity, 10.7% PPV, and 96.7% NPV. The logistic regression model described as P = 1/(1+e(1.643 - 0.006* × TBIL (µmol/L) -- 1.302* × INR + 0.095* × ALB (g/L))) had 88.5% sensitivity, 73.1% specificity, 16.3% PPV, and 99.1% NPV at the cut-off of 0.04778 and kept 94.4% sensitivity, 66.8% specificity, 15.2% PPV, and 99.5% NPV in external validation. CONCLUSIONS: The logistic regression model provided superior performance than Hy's law, DrILTox ALF Score, and Robles-Diaz Model for predicting DILI -related ALF.

CHALF Score: A Novel Tool to Rapidly Risk Stratify Children in Need of Liver Transplant Evaluation During Acute Liver Failure.

BACKGROUND: Pediatric acute liver failure (PALF) can require emergent liver transplantation (LT, >25%) or lead to death (~15%). Existing models cannot predict clinical trajectory or survival with native liver (SNL). We aimed to create a predictive model for PALF clinical outcomes based on admission variables. METHODS: A retrospective, single-center PALF cohort (April 2003 to January 2022) was identified using International Classification of Disease codes, selected using National Institutes of Health PALF Study Group (PALFSG) criteria, and grouped by clinical outcome (SNL, LT, or death). Significant admission variables were advanced for feature selection using least absolute shrinkage and selection operator regression with bootstrapping (5000×). A predictive model of SNL versus LT or death was created using logistic regression and validated using PALFSG data. RESULTS: Our single-center cohort included 147 patients (58% SNL, 32% LT, 10% expired), while the PALFSG validation cohort included 492 patients (50% SNL, 35% LT, 15% expired). Admission variables associated with SNL included albumin (odds ratio [OR], 16; P < 0.01), ammonia (OR, 2.37; P < 0.01), and total bilirubin (OR, 2.25; P < 0.001). A model using these variables predicted SNL versus LT or death with high accuracy (accuracy [0.75 training, 0.70 validation], area under the curve [0.83 training, 0.78 validation]). A scaled score (CHLA-acute liver failure score) was created that predicted SNL versus LT or death with greater accuracy (C statistic 0.83) than Pediatric End-Stage Liver Disease (C statistic 0.76) and admission liver injury unit (C statistic 0.76) scores. CONCLUSIONS: The CHLA-acute liver failure score predicts SNL versus LT or mortality in PALF using admission laboratories with high accuracy. This novel, externally validated model offers an objective guide for urgent referral to a pediatric LT center.

TCD assessment in fulminant hepatic failure: Improvements in cerebral autoregulation after liver transplantation.

INTRODUCTION AND OBJECTIVES: Acute liver failure, also known as fulminant hepatic failure (FHF), includes a spectrum of clinical entities characterized by acute liver injury, severe hepatocellular dysfunction and hepatic encephalopathy. The objective of this study was to assess cerebral autoregulation (CA) in 25 patients (19 female) with FHF and to follow up with seventeen of these patients before and after liver transplantation. PATIENTS AND METHODS: The mean age was 33.8 years (range 14-56, SD 13.1 years). Cerebral hemodynamics was assessed by transcranial Doppler (TCD) bilateral recordings of cerebral blood velocity (CBv) in the middle cerebral arteries (MCA). RESULTS: CA was assessed based on the static CA index (SCAI), reflecting the effects of a 20-30 mmHg increase in mean arterial blood pressure on CBv induced with norepinephrine infusion. SCAI was estimated at four time points: pretransplant and on the 1st, 2nd and 3rd posttransplant days, showing a significant difference between pre- and posttransplant SCAI (p = 0.005). SCAI peaked on the third posttransplant day (p = 0.006). Categorical analysis of SCAI showed that for most patients, CA was reestablished on the second day posttransplant (SCAI > 0.6). CONCLUSIONS: These results suggest that CA impairment pretransplant and on the 1st day posttransplant was re-established at 48-72 h after transplantation. These findings can help to improve the management of this patient group during these specific phases, thereby avoiding neurological complications, such as brain swelling and intracranial hypertension.

Waitlist and posttransplant outcomes of pregnancy-related acute liver failure in the United States.

Data on the liver transplant (LT) outcomes of women with acute liver failure (ALF) due to liver diseases unique to pregnancy (P-ALF) are limited. Using United Network of Organ Sharing (UNOS) data (1987-2021), we analyzed waitlist and post-LT outcomes of ALF in women of childbearing age comparing P-ALF versus ALF due to liver diseases not unique to pregnancy. Baseline characteristics were compared between groups at the time of listing for LT. Of 3542 females aged 16-43 years and listed for LT for ALF, 84 (2%) listed for P-ALF were less likely to be Black (11 vs. 21%, p =0.033), have lower international normalized ratio (2.74 vs. 4.53 p <0.002), but more likely to have respiratory failure (56% vs. 41%, p <0.005), be on pressors (58% vs. 43%, p <0.005), and require dialysis (23% vs. 10%, p <0.001). The cumulative 90-day waitlist mortality (WLM) was lower in P-ALF vs. ALF due to liver diseases not unique to pregnancy (7.4 vs. 16.6%, p <0.001). Posttransplant survival rates at 5 years were similar (82% vs. 79%, p =0.89). In a Fine and Gray regression model controlled for listing year and Model for End-Stage Liver Disease score, 90-day WLM was lower in P-ALF with a sub-HR of 0.42 (95% CI: 0.19-0.94, p =0.035). Of 84 women with P-ALF and listed for LT, 45 listed for hemolysis-elevated liver enzymes-low platelets (HELLP) versus 39 for acute fatty liver of pregnancy had higher 90-day WLM (19.3% vs. 5.7% p <0.005). The 90-day WLM was about 10-fold higher in HELLP versus acute fatty liver of pregnancy with a sub-HR of 9.97 (95% CI: 1.64-60.55, p =0.013). In this UNOS database analysis of ALF among women of childbearing age, the waitlist outcome is better in women with P-ALF compared to women with ALF due to liver diseases not unique to pregnancy. Among women with P-ALF, the 90-day WLM is worse for HELLP versus acute fatty liver of pregnancy. Further studies are needed to improve the management of HELLP and prevent the development of ALF in this subgroup population.

Successful results of early nucleos(t)ide analogue treatment for liver transplantation candidates with severe acute hepatitis B infection.

BACKGROUND: Early treatment of severe acute hepatitis B virus (HBV) infection with nucleos(t)ide analogues may prevent progression to acute liver failure (ALF). PATIENTS AND METHODS: The charts of 24 patients who were treated for severe acute HBV infection (either INR ≥ 1.5 or INR≥ 1.4 and total bilirubin ≥ 20 mg/dL at the referring institution or after admission) between April 2021 and May 2023 (inclusive) were evaluated retrospectively. Twelve patients were women; median [range] age: 48 [35-68]. Entecavir (0.5 mg/day) (n = 16) or tenofovir disoproxil fumarate (245 mg/day) (n =8) were used depending on availability. RESULTS: Two patients required liver transplant which was performed successfully in one (no suitable donor for the other). Deterioration to ALF was prevented in 22 of the 24 cases (92%); these patients could be discharged after median (range) 12 (5-24) days following initiation of the antiviral drug. There was no significant difference in efficacy between the two antiviral agents. The anti-HBsAg antibody became positive in 16 patients (73%); one other patient became HBsAg negative at 1 month after discharge but was lost to follow up. Five patients (23%) are still HBsAg positive but all except one have started treatment in the last 6 months. One of the recently treated 4 patients stopped taking the antiviral drug at his own will and one has become anti-HIV antibody positive during follow up. CONCLUSION: Early treatment of severe acute HBV infection with entecavir or tenofovir disoproxil fumarate prevents the need for liver transplant and consideration of living donors.

SCYL1 deficiency: A rare entity with challenging neurological manifestations after liver transplantation.

BACKGROUND: Pediatric acute liver failure (PALF) with undetermined etiology is associated with higher liver transplantation and lower spontaneous recovery (transplant-free) rates. The diagnostic odyssey in PALF cases hinders appropriate management and follow-up after liver transplantation. Advances in whole exome sequencing analysis have already been successful at identifying new genetic causes of PALF. CASE PRESENTATION: We report a 17-year-old girl who underwent liver transplantation at the age of 7 months due to acute liver failure and presented later with abnormal neurological manifestations, that is, gait disturbances, dysarthria, and mental retardation that led us to the diagnosis of SCYL1 deficiency. CONCLUSION: PALF cases should be screened for possible underlying genetic disorders. Genetic studies and reanalysis of whole-genome sequencing data may help identify new cases and clarify the genotype-phenotype correlation. SCYL1 deficiency should be suspected in PALF patients who develop neurological involvement after LT. Early diagnosis is vital for proper management of ALF crises in SCYL1 deficiency patients. Despite the reported favorable outcomes of ALF crises in SCYL1 deficiency, liver transplantation decision should be discussed on a case-by-case basis.

A Report on a Nationwide Surveillance System for Pediatric Acute Hepatitis of Unknown Etiology in Korea.

BACKGROUND: Several cases of pediatric acute hepatitis of unknown etiology related to adenoviral infections have been reported in Europe since January 2022. The aim of this study was to compare the incidence, severity, possible etiology, and prognosis of the disease with those in the past in Korea. METHODS: The surveillance group collected data between May and November 2022 using a surveillance system. Acute hepatitis of unknown etiology was defined in patients aged < 16 years with a serum transaminase level > 500 IU/L, not due to hepatitis A-E or other underlying causes. For comparison, data from 18 university hospitals were retrospectively collected as a control group between January 2021 and April 2022. RESULTS: We enrolled 270 patients (mean age, 5 years). The most common symptom was fever. However, the incidence was similar between 2021 and 2022. Liver function test results, number of patients with acute liver failure (ALF), liver transplantation (LT), death, and adenovirus detection rates did not differ between the two groups. None of the adenovirus-positive patients in either group experienced ALF, LT, or death. In the surveillance group, adenovirus-associated virus-2 was detected in four patients, one of whom underwent LT. Patients with an unknown etiology showed significantly higher bilirubin levels, a lower platelet count, and a higher LT rate than patients with a possible etiology. CONCLUSION: The incidence of pediatric acute hepatitis of unknown etiology and adenovirus detection rate have not increased in Korea.

ABO-Incompatible Orthotopic Liver Transplant as a Rescue Strategy for Fulminant Hepatic Failure in a Recipient With Breast Cancer: Highlights on Transplant Management.

Pretransplant malignancy unrelated to hepatocellular carcinoma is a challenging condition in liver transplantation. Standard of care requires the completion of treatments and a disease-free period before the transplant. However, in the setting of a fulminant hepatic failure, these steps cannot be achieved. A 46-year-old woman with a recent diagnosis of stage 2 breast cancer presented to our center with a fulminant hepatic failure of unknown origin. Because of the rapid worsening of her clinical status, she was listed as eligible for transplant after a multidisciplinary evaluation. Because of a shortage of available donors, a deceased donor ABO-incompatible liver transplant with a synchronous mastectomy and first-level axillary lymphadenectomy was performed. To prevent antibody-mediated rejection, a triple immunosuppression therapy and a postoperative therapeutic plasmapheresis were performed. The patient remains without cancer recurrence at 18 months of follow-up. Recent studies have shown that cancer recurrence in recipients with pretransplant malignancy is considerably lower than suggested in previously published studies. However,this data is not sufficient to establish evidence-based guidelines on the indications and timing of transplant. In selected cases, the presence of a pretransplant malignancy does notrepresent a contraindication for a rescue liver transplant. Further studies are needed to stratify the risk and to help clinicians to choose the best strategy in an urgent context such as this.

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.

Clinical Aspects and Etiologic Investigation of Pediatric Patients With Acute Liver Failure.

A new outbreak of hepatitis of unknown origin raised awareness in the international community. A few reports have attempted to associate new cases with adenovirus infection and the immunologic effects of previous SARS-CoV-2 infections through a superantigen mechanism. Moreover, according to a case series, viral isolates were identified in 7 of 10 cases of pediatric patients with hepatitis of unknown origin and acute liver failure. Adenovirus was detected by respiratory secretion polymerase chain reaction in 2 patients, with neither presenting with SARS-CoV-2 acute infection. Clinical and laboratory descriptions and cross-referencing epidemiologic and pathophysiological data can help identify possible disease etiologies.