Liver Biopsy Can Be Safely Performed in Pediatric Acute Liver Failure to Aid in Diagnosis and Management

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

Effector memory CD8 T-cells as a novel peripheral blood biomarker for activated T-cell pediatric acute liver failure

A distinct phenotype of pediatric acute liver failure (PALF) has been identified, labeled activated T-cell hepatitis. These patients, previously included within the indeterminate group, have evidence of systemic immune activation and liver biopsy specimens with dense infiltration of CD8+ T-cells. We aimed to evaluate the peripheral blood T-cell phenotype in PALF patients with activated T-cell hepatitis compared to indeterminate cause. PALF patients with unknown etiology age 1-17 years were prospectively enrolled between 2017-2020. Within the unknown group, patients were classified as either activated T-cell hepatitis if they had a liver biopsy with dense or moderate CD8 staining and an elevated soluble interleukin-2 receptor level, or they were classified as indeterminate if they did not meet these criteria. Whole blood was collected for flow cytometry and T-cell phenotyping. Four patients with activated T-cell hepatitis and 4 patients with indeterminate PALF were enrolled. Activated T-cell hepatitis patients had significantly greater percentage of CD8 T-cells that were effector memory (TEM) phenotype compared to indeterminate PALF patients (median 66.8% (IQR 57.4-68.7) vs 19.1% (IQR 13.4-25.2), P = 0.03). In addition, CD8+ TEM cells in activated T-cell hepatitis patients were significantly more likely to be CD103 positive, a marker of tissue resident memory T-cells, compared to indeterminate PALF patients (median 12.4% (IQR 9.5-14.7) vs 4.7% (IQR 4.5-5.3), P = 0.03). We found patients with activated T-cell hepatitis can be identified by the unique pattern of increased percentage of peripheral blood effector memory CD8+ CD103+ T-cells. These findings will guide future studies exploring the T-cell phenotype for these patients and whether they may respond to directed immunosuppressive therapies.

Pediatric liver cirrhosis interventional procedures: from biopsy to transjugular intrahepatic portosystemic shunt

Cirrhosis is a complex diffuse process whereby the architecture of the liver is replaced by abnormal nodules because of the presence of fibrosis. Several pediatric diseases such as extrahepatic portal vein obstruction, biliary atresia, alpha-1-antitrypsin deficit and autoimmune hepatitis can lead to cirrhosis and portal hypertension in children. In this article the authors describe interventional radiology procedures that can facilitate the diagnosis and treatment of diseases associated with liver cirrhosis and portal hypertension in the pediatric population. These procedures include image-guided liver biopsy, mesenteric-intrahepatic left portal vein shunts, balloon-occluded retrograde transvenous obliteration, transjugular intrahepatic portosystemic shunts and splenic embolization.

Pediatric acute liver failure: Reexamining key clinical features, current management, and research prospects

This review aims to synthesize the most updated research, outcomes, and trends in the field of pediatric liver transplantation (LT), specifically focusing on children who have suffered from acute liver failure. Pediatric acute liver failure is a dynamic, life-threatening condition that can either self-resolve or lead to death. LT is a lifesaving intervention. With the introduction of technical variant grafts and recent immunosuppression modifications, overall patient survival, graft survival, and waitlist mortality have improved. Furthermore, recent advances in the knowledge of immunologic mediators of acute liver failure offer the possibility of more detailed understanding of the pathophysiology and new areas for research. Given the success of living donor LT for pediatric patients with acute liver failure, this option should continue to be actively considered as an alternative treatment option for patients who are listed for transplantation and are managed at a multidisciplinary tertiary care transplant center.

Emergencies in paediatric hepatology

The aetiology of several liver diseases in children is age specific and many of these conditions have significant and potentially long-term clinical repercussions if not diagnosed early and managed in a timely fashion. We address 5 clinical scenarios that cover most of the diagnostic and therapeutic emergencies in children: infants with liver disease; acute liver failure; management of bleeding varices; liver-based metabolic disorders; and liver tumours and trauma. A wide spectrum of conditions that cause liver disease in infants may present as conjugated jaundice, which could be the only symptom of time-sensitive disorders - such as biliary atresia, metabolic disorders, infections, and haematological/alloimmune disorders - wherein algorithmic multistage testing is required for accurate diagnosis. In infantile cholestasis, algorithmic multistage tests are necessary for an accurate early diagnosis, while vitamin K, specific milk formulae and disease-specific medications are essential to avoid mortality and long-term morbidity. Management of paediatric acute liver failure requires co-ordination with a liver transplant centre, safe transport and detailed age-specific aetiological work-up - clinical stabilisation with appropriate supportive care is central to survival if transplantation is indicated. Gastrointestinal bleeding may present as the initial manifestation or during follow-up in patients with portal vein thrombosis or chronic liver disease and can be managed pharmacologically, or with endoscopic/radiological interventions. Liver-based inborn errors of metabolism may present as encephalopathy that needs to be recognised and treated early to avoid further neurological sequelae and death. Liver tumours and liver trauma are both rare occurrences in children and are best managed by a multidisciplinary team in a specialist centre.

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.

EUS-guided fine-needle liver biopsy in pediatric patients using a modified technique with one-pass, one-actuation wet suction

BACKGROUND AND AIMS

Liver biopsy (LB) can be a valuable tool to determine the etiology of pediatric liver disease. There is limited data of the role of EUS-LB in children. We have evaluated the efficacy and the safety of a modified technique (M)LB in high risk or obese children. Additionally, we aimed to compare the tissue yield of EUS-(M)LB and percutaneous (PC) approach.

METHODS

A retrospective analysis comparing EUS-(M)LB and PC-LB in children at a tertiary referral center. All consecutive children referred for PC-LB and EUS-LB who had an unexplained liver test abnormality after exclusion of biliary disorders from march-2017 to August-2018 were included. EUS-(M)LB consists of a one pass wet suction technique using a 19-gauche core needle. Comparison between total specimen length (TSL) and number of complete portal triads (CPTs) between the groups were performed.

RESULTS

There were 28 EUS-(M)LB and 28 PC-LB pediatric cases. The median (IQR) age was 14.5 years (13.4-16). The median TSL was 8.6 (5.8-9.6) in EUS-(M)LB cases and 7 cm (7-9) in PC-LB cases (P =0.788). The maximum intact specimen was 2.8 cm (EUS-(M)LB) and 1.6 cm (PC-LB) (P =0.009). The mean (SD) number of CPTs per sample was 28.2 (7.3) and 11.6 (2.1), respectively (P =0.001). Adverse events included once case of self-limited abdominal pain in the PC-LB group.

CONCLUSION

EUS-(M)LB has the potential to be a safe and effective alternative diagnostic modality, at when compared to PC-LB, to evaluate children with unexplained liver test abnormalities who undergo EUS to evaluate biliary disorders.

What Laboratory Tests and Physiologic Triggers Should Guide the Decision to Administer a Platelet or Plasma Transfusion in Critically Ill Children and What Product Attributes Are Optimal to Guide Specific Product Selection? From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present consensus statements and supporting literature for plasma and platelet product variables and related laboratory testing for transfusions in general critically ill children from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill pediatric patients at risk of bleeding and receiving plasma and/or platelet transfusions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 10 experts developed evidence-based and, when evidence was insufficient, expert-based statements for laboratory testing and blood product attributes for platelet and plasma transfusions. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative - Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed five expert consensus statements and two recommendations in answer to two questions: what laboratory tests and physiologic triggers should guide the decision to administer a platelet or plasma transfusion in critically ill children; and what product attributes are optimal to guide specific product selection?

CONCLUSIONS

The Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding program provides some guidance and expert consensus for the laboratory and blood product attributes used for decision-making for plasma and platelet transfusions in critically ill pediatric patients.

Plasma and Platelet Transfusion Strategies in Critically Ill Children Following Noncardiac Surgery and Critically Ill Children Undergoing Invasive Procedures Outside the Operating Room: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present consensus statements and supporting literature for plasma and platelet transfusions in critically ill children following noncardiac surgery and critically ill children undergoing invasive procedures outside the operating room from the Transfusion and Anemia EXpertise Initiative - Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill children undergoing invasive procedures outside of the operating room or noncardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 10 experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill children following noncardiac surgery or undergoing invasive procedures outside of the operating room. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed eight expert consensus statements focused on the critically ill child following noncardiac surgery and 10 expert consensus statements on the critically ill child undergoing invasive procedures outside the operating room.

CONCLUSIONS

Evidence regarding plasma and platelet transfusion in critically ill children in this area is very limited. The Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding Consensus Conference developed 18 pediatric specific consensus statements regarding plasma and platelet transfusion management in these critically ill pediatric populations.

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.

Safety, Feasibility, Yield, Diagnostic and Prognostic Implications of Transjugular Liver Biopsy in Children and Adolescents

OBJECTIVES

The objectives of the study were to evaluate the indications, feasibility, complications and clinical implications of transjugular liver biopsy (TJLB) in children.

METHODS

Data of all TJLB performed in children <18 years old was retrieved from the computerized hospital information system. TJLB was done using a 19 G quick-core needle biopsy system with 20 mm throw length. Hepatic venous pressure gradient was additionally measured in children with portal hypertension. A single pathologist reviewed all the biopsies again and provided structured information.

RESULTS

A total of 102 children, including 5 with acute liver failure underwent TJLB with technical success in 101 (99%). A mean of 2.3 ± 0.9 passes (range: 1-5) was taken for the biopsy. The most common indications for TJLB in our cohort were elevated international normalized ratio >1.5 (66, 64.7%), ascites (46, 45.1%) and thrombocytopenia (platelet count < 60,000/mm3) (42, 41.2%). Mean size of the tissue received was 14.5 ± 5.6 mm with an average of 10.2 ± 4.7 portal tracts. Only one child developed major (category D) complication (hemobilia) and 12 (11.8%) developed minor complications post-procedure. Etiological diagnosis could be made in a total of 64 (63.9%) children undergoing TJLB, the most common diagnosis being autoimmune hepatitis (n = 31), non-cirrhotic portal fibrosis (n = 16) and drug-induced liver injury (n = 4).

CONCLUSION

TJLB is well tolerated, feasible and helps make a diagnosis in close to 64% children allowing timely medical and/or surgical intervention. It is especially useful for diagnosis of autoimmune liver diseases, drug-induced liver injury and non-cirrhotic portal fibrosis.

Applying an Age-specific Definition to Better Characterize Etiologies and Outcomes in Neonatal Acute Liver Failure

OBJECTIVE

Neonatal acute liver failure (ALF) is a rare disease with high mortality for which no standard age-specific definition exists. To advance the understanding of neonatal ALF, we characterize the etiology, presenting features, treatment, and outcomes in infants within 1 month of life.

METHODS

We performed a single-center 11-year retrospective chart review of neonates ≤30 days of life with ALF as defined by an INR of ≥2.0. Comparisons were made by etiology and survival with native liver (SNL). Estimated survival was performed using the Kaplan-Meier method.

RESULTS

Forty-three patients met inclusion criteria for neonatal ALF. Etiologies included viral infection (23%), gestational alloimmune liver disease with neonatal hemochromatosis (GALD-NH) (21%), cardiac-associated ischemia (16%), other ischemia (14%), genetic etiologies (9%), Trisomy 21-associated myelodysplasia (TAM) (7%), hemophagocytic lymphohistiocytosis (HLH) (2%), and not identified (7%). Infants with viral etiologies had the highest alanine aminotransferase (ALT) at presentation (1179 IU/L, interquartile range [IQR] 683-1585 IU/L) in contrast to low levels in GALD-NH (23 IU/L, IQR 18-64 IU/L). Across all etiologies, only 33% were alive at 1 year. Overall median survival was 74 days; 17 days for viral infection and 74 days for GALD-NH. Among laboratory values at presentation, alpha-fetoprotein (AFP) was significantly higher in patients that survived with their native liver (P = 0.04).

CONCLUSIONS

Overall, outcome for neonatal ALF is poor. Although initial laboratory values can differentiate viral infection or GALD-NH, further studies are needed to identify laboratory parameters that predict SNL by etiology to ultimately improve patient outcomes.

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.

Transfusion in Pediatric Patients: Review of Evidence-Based Guidelines

Children require transfusion of blood components for a vast array of medical conditions, including acute hemorrhage, hematologic and nonhematologic malignancies, hemoglobinopathy, and allogeneic and autologous stem cell transplant. Evidence-based literature on pediatric transfusion practices is limited, particularly for non-red blood cell products, and many recommendations are extrapolated from studies in adult populations. Recognition of these knowledge gaps has led to increasing numbers of clinical trials focusing on children and establishment of pediatric transfusion working groups in recent years. This article reviews existing literature on pediatric transfusion therapy within the larger context of analogous data in adult populations.

Activated CD8 T-cell Hepatitis in Children With Indeterminate Acute Liver Failure: Results From a Multicenter Cohort

OBJECTIVES

In many pediatric acute liver failure (PALF) cases, a diagnosis is not identified, and the etiology is indeterminate (IND-PALF). Our pilot study found dense CD8 T-cell infiltrates and increased T-cell clonality in liver specimens from IND-PALF patients. We aimed to validate these findings in a multicenter cohort with investigators blinded to diagnosis.

METHODS

PALF Study Group registry subjects with IND-PALF (n = 37) and known diagnoses (DX-PALF) (n = 18), ages 1 to 17 years, with archived liver tissue were included. Liver tissue slides were stained for T cells (CD8 and CD4), B cells (CD20), macrophages (CD163), perforin, and tissue resident-memory T cells (Trm, CD103), and scored as minimal, moderate, or dense. Lymphocytes were isolated from frozen liver tissue for T-cell receptor beta (TCRβ) sequencing.

RESULTS

Dense hepatic CD8 staining was found in significantly more IND-PALF (n = 29, 78%) compared with DX-PALF subjects (n = 5, 28%) (P = 0.001). IND-PALF subjects were more likely to have dense or moderate perforin (88% vs 50%, P = 0.03) and CD103 (82% vs 40%, P = 0.02) staining compared with DX-PALF subjects. TCRβ sequencing of 15 IND-PALF cases demonstrated increased clonal overlap compared with 6 DX-PALF cases (P = 0.002).

CONCLUSIONS

Dense infiltration of effector Trm CD8 T cells characterizes liver tissue from IND-PALF subjects. Increased clonality suggests the T-cell expansion is antigen(s)-driven as opposed to a nonspecific inflammatory response. These findings support CD8 staining as a new biomarker of the activated CD8 T-cell PALF phenotype. Future studies are needed to characterize potential antigens, host risk factors, and inflammatory pathways with the goal of developing targeted therapies.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.