Severe acute liver disease in adults: Contemporary role of histopathology.

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

Designing Clinical Trials in Wilson's Disease.

BACKGROUND AND AIMS: Wilson's disease (WD) is an autosomal-recessive disorder caused by ATP7B gene mutations leading to pathological accumulation of copper in the liver and brain. Adoption of initial treatments for WD was based on empirical observations. These therapies are effective, but there are still unmet needs for which treatment modalities are being developed. An increase of therapeutical trials is anticipated. APPROACH AND RESULTS: The first Wilson Disease Aarhus Symposium (May 2019) included a workshop on randomized clinical trial design. The authors of the article were organizers or presented during this workshop, and this article presents their consensus on the design of clinical trials for WD, addressing trial population, treatment comparators, inclusion and exclusion criteria, and treatment endpoints. To achieve adequate recruitment of patients with this rare disorder, the study groups should include all clinical phenotypes and treatment-experienced as well as treatment-naïve patients. CONCLUSIONS: The primary study endpoint should be clinical or a composite endpoint until appropriate surrogate endpoints are validated. Standardization of clinical trials will permit pooling of data and allow for better treatment comparisons, as well as reduce the future numbers of patients needed per trial.

Hepatic ultrastructural features distinguish paediatric Wilson disease from NAFLD and autoimmune hepatitis.

BACKGROUND AND AIMS: Wilson disease (WD) has diverse presentations that frequently mimic other liver diseases. Distinguishing WD from non-alcoholic fatty liver disease (NAFLD) and autoimmune hepatitis (AIH), can be difficult and has critical implications for medical management. This study aimed to examine the utility of histological features of WD in children compared to those with NAFLD and AIH. METHODS: A review of liver biopsy slides was performed in children with a clinical and/or genetic diagnosis of WD, seen at the Hospital for Sick Children between 1981 and 2019 and compared to controls with NAFLD and AIH. 37 children with WD and 37 disease controls (20 NAFLD; 17 AIH) were included. Three pathologists, blind to clinical details and diagnosis, reviewed all liver biopsies to reach consensus. Clinical and histopathologic features were compared between groups. RESULTS: Most WD cases displayed steatosis or steatohepatitis on histology (34/37), active AIH-pattern in 1 and inactive cirrhosis in 2 cases. Electron microscopy (EM) findings of mitochondrial abnormalities including dilated tips of cristae, pleomorphism, membrane duplication and dense matrix were more frequent in the WD group as compared to disease controls (p < 0.0001). In WD, dilated tips of mitochondrial cristae had a sensitivity of 91% and specificity of 86%, best among EM features. CONCLUSIONS: Light microscopic findings display considerable overlap among children with WD, NAFLD and AIH. Ultrastructural findings of mitochondrial abnormalities are important to distinguish WD from NAFLD and AIH. EM examination should be considered essential in the diagnostic work-up of paediatric liver biopsies.

Management of Wilson Disease Diagnosed in Infancy: An Appraisal of Available Experience to Generate Discussion.

Increased access to molecular genetic testing is changing the demographics for diagnosing inherited disorders and imposing new challenges for medical management. Wilson disease (WD), typically diagnosed in older children and adults, can now be detected in utero and in infants (children younger than 24 months, including neonates) via genetic testing. An evidence-based approach to management of these neonates and extremely young children, who are typically asymptomatic, has been hampered by lack of clinical experience. We present a case of an infantile diagnosis of WD, review available experience, and discuss current trends in antenatal genetic testing of parents and fetus that may lead to a very early diagnosis of WD. Based on physiological and nutritional considerations, we propose an algorithmic approach to management of infantile WD as a starting point for further discussion. Future collaboration amongst specialists is essential to identify evidence-based approaches and best practice for managing treatment of infants with genetically diagnosed WD.

Hepatitis C in 2020: A North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper.

In 1989, a collaboration between the Centers for Disease Control (CDC) and a California biotechnology company identified the hepatitis C virus (HCV, formerly known as non-A, non-B hepatitis virus) as the causative agent in the epidemic of silent posttransfusion hepatitis resulting in cirrhosis. We now know that, the HCV genome is a 9.6 kb positive, single-stranded RNA. A single open reading frame encodes a 3011 amino acid residue polyprotein that undergoes proteolysis to yield 10 individual gene products, consisting of 3 structural proteins (core and envelope glycoproteins E1 and E2) and 7 nonstructural (NS) proteins (p7, NS2, NS3, NS4A, NS4B, NS5A, and NS5B), which participate in posttranslational proteolytic processing and replication of HCV genetic material. Less than 25 years later, a new class of medications, known as direct-acting antivirals (DAAs) which target these proteins, were introduced to treat HCV infection. These highly effective antiviral agents are now approved for use in children as young as 3 years of age and have demonstrated sustained virologic responses exceeding 90% in most genotypes. Although tremendous scientific progress has been made, the incidence of acute HCV infections has increased by 4-fold since 2005, compounded in the last decade by a surge in opioid and intravenous drug use. Unfortunately, awareness of this deadly hepatotropic virus among members of the lay public remains limited. Patient education, advocacy, and counseling must, therefore, complement the availability of curative treatments against HCV infection if this virus is to be eradicated.

Pediatric Wilson Disease Presenting as Acute Liver Failure: An Individual Patient Data Meta-analysis.

OBJECTIVES: Wilson disease (WD) presenting as acute liver failure (ALF) is rare and typically fatal without liver transplantation (LT). Its rarity has hindered comprehensive studies. We undertook an individual patient data meta-analysis to characterize a cohort of pediatric patients presenting with ALF whose final diagnosis was WD to examine outcomes and identify predictors of poor outcomes. METHODS: Database searches were conducted in PubMed, ScienceDirect, and Google Scholar, restricted to English-language articles published between January 1984 and May 2018. Articles were excluded if pediatric (<18 years old) data were not extractable or if LT was not readily available at reporting institutions. Extracted data included clinical and biochemical characteristics, genotype, treatment, and outcome. RESULTS: Data were available on 249 subjects from 52 articles, plus 7 additional subjects identified from our institution's WD database (N = 256). Females represented 69% (n = 170/245). Median age at presentation was 13.4 years (n = 204, range 4.0-17.9). Of the total 256 subjects, 87% underwent LT, 11% achieved spontaneous recovery and 2% died before LT. International normalized ratio >2.0 at presentation was a predictor of LT/death (odds ratio 7.6, 95% confidence interval 1.5-28), with a trend observed for hepatic encephalopathy (HE) (odds ratio 4.18, 95% confidence interval 0.99-18). Arithmetic diagnostic scores proved inferior in the pediatric age-bracket compared to adults. CONCLUSIONS: This large international pediatric cohort has permitted an individual patient data analysis of WD presenting as ALF. Notably, 11% of subjects achieved spontaneous survival; the rest required LT. Coagulopathy (international normalized ratio >2:0) and HE at presentation heralded poor outcomes. Further prospective studies may identify additional early predictors of outcomes.

Update on the Diagnosis and Management of Wilson Disease.

PURPOSE OF REVIEW: Exciting developments relating to Wilson disease (WD) have taken place with respect to both basic biological and clinical research. This review critically examines some of these findings and considers their implications for current thinking about WD. It is not a comprehensive review of WD as a clinical disorder. RECENT FINDINGS: The structure of the gene product of ATP7B, abnormal in WD, is being worked out in detail, along with a broader description of how the protein ATP7B (Wilson ATPase) functions in cells including enterocytes, not only in relation to copper disposition but also to lipid synthesis. Recent population studies raise the possibility that WD displays incomplete penetrance. Innovative screening techniques may increase ascertainment. New strategies for diagnosing and treating WD are being developed. Several disorders have been identified which might qualify as WD-mimics. WD can be difficult to diagnose and treat. Insights from its pathobiology are providing new options for managing WD.

Early Posthepatoportoenterostomy Predictors of Native Liver Survival in Biliary Atresia.

OBJECTIVES: Most infants with biliary atresia (BA) require liver transplantation (LT) after hepatoportoenterostomy (HPE), including those who initially clear jaundice. The aim of the present study was to identify clinical and routine laboratory factors in infants with BA post-HPE that predict native liver survival at 2 years. METHODS: A retrospective cohort study was conducted in 217 patients with BA undergoing HPE in Sydney, Australia and Toronto, Canada between January 1986 and July 2009. Univariate and multivariate logistic regression using backwards-stepwise elimination identified variables at 3 months after HPE most associated with 2-year native liver survival. RESULTS: Significant variables (P < 0.05) on univariate analysis included serum total bilirubin (TB) and albumin at 3 months post-HPE, bridging fibrosis or cirrhosis on initial liver biopsy, ascites of <3 months post-HPE, type 3 BA anatomy, age at HPE of >45 days, change in length z scores within 3 months of HPE, and center. On multivariate analysis, TB (P < 0.0001) and albumin (P = 0.02) at 3 months post-HPE, and center (P = 0.0003) were independently associated with native liver survival. Receiver operating characteristic analysis revealed an optimal cut-off value of TB <74 µmol/L (4.3 mg/dL; area under the receiver operating characteristic curve 0.8990) and serum albumin level >35 g/L (3.5 mg/dL; area under the receiver operating characteristic curve 0.7633) to predict 2-year native liver survival. TB and albumin levels 3 months post-HPE defined 3 groups (1: TB ≤74 µmol/L, albumin >35 g/L; 2: TB ≤74 µmol/L, albumin ≤35 g/L; 3: TB >74 µmol/L) with distinct short- and long-term native liver survival rates (log-rank P < 0.001). Length z scores 3 months post-HPE were poorer for group 2 than group 1 (-0.91 vs -0.30, P = 0.0217) with similar rates of coagulopathy. CONCLUSIONS: Serum TB and albumin levels 3 months post-HPE independently predicted native liver survival in BA when controlling for center. Serum albumin level <35 g/L in infants with BA who were no longer jaundiced at 3 months post-HPE was a poor prognostic indicator. Poorer linear growth and absence of significant coagulopathy suggest a role for early aggressive nutritional therapy in this group.

Controversies and Variation in Diagnosing and Treating Children With Wilson Disease: Results of an International Survey.

OBJECTIVES: Variation in care is more common in settings in which evidence-based approaches are limited. The aims of the present study were to describe consensus and variability in approaches taken by pediatric hepatologists in the management of Wilson disease (WD) in children. METHOD: International case-centered, Internet-based survey of pediatric hepatologists. Survey cases were developed by consensus of the authors and were intended to identify variation in the care of children with WD. RESULTS: One hundred eleven of 253 clinicians responded (44%). Of these, 84% of North American and 41% of European participants used guidelines published in their respective region. Although consensus existed on the first-line diagnostic tools (serum ceruloplasmin and baseline 24-hour urinary copper excretion), survey participants did not agree on how much liver copper content was required for diagnosis: 57% considered >250 µg/g dry weight to be consistent with WD, whereas 25% considered >50 µg/g to be diagnostic. Overall, 50% of practitioners perform genetic testing in all suspected cases, and 81% perform genetic testing once they know the genotype of an index patient. For initial treatment of fulminant WD, 51% of participants chose chelation and 15% chose immediate transplantation; 47% chose listing for transplantation followed by monitoring using a disease-severity score, and then carrying out transplantation only when the score reached a critical cut-off. To treat mildly affected siblings of index patients, 43% of practitioners chose zinc. Most reported that they use chelation to treat patients with hepatic dysfunction; however, 29% of North American participants chose not to use D-penicillamine as primary therapy. CONCLUSIONS: From an international perspective, pediatric hepatologists vary in the approaches they use in the care for children with WD. Regional preferences and accessibility to treatments may generate variation. Unwarranted variation, however, may also contribute to differences in outcome and should be targeted to improve quality of care.

Pathology of the liver sinusoids.

The hepatic sinusoids comprise a complex of vascular conduits to transport blood from the porta hepatis to the inferior vena cava through the liver. Under normal conditions, portal venous and hepatic artery pressures are equalized within the sinusoids, oxygen and nutrients from the systemic circulation are delivered to the parenchymal cells and differentially distributed throughout the liver acini, and proteins of liver derivation are carried into the cardiac/systemic circulation. Liver sinusoid structures are lined by endothelial cells unique to their location, and Kupffer cells. Multifunctional hepatic stellate cells and various immune active cells are localized within the space of Disse between the sinusoid and the adjacent hepatocytes. Flow within the sinusoids can be compromised by physical or pressure blockage in their lumina as well as obstructive processes within the space of Disse. The intimate relationship of the liver sinusoids to neighbouring hepatocytes is a significant factor affecting the health of hepatocytes, or transmission of the effects of injury within the sinusoidal space. Pathologists should recognize several patterns of injury involving the sinusoids and surrounding hepatocytes. In this review, injury, alterations and accumulations within the liver sinusoids are illustrated and discussed.

Metalloproteomics: focus on metabolic issues relating to metals.

PURPOSE OF REVIEW: By determining metalloproteomes via high-throughput methodology, metalloproteomics provides a research strategy for investigating nutritional and metabolic issues relating to metals. In this review, we examine recent developments in metalloproteomics since its early days approximately 12 years ago, when we utilized metalloproteomics to investigate copper disposition in hepatocytes in relation to Wilson disease. RECENT FINDINGS: A metalloproteome is the set of proteins that have metal-binding capacity by being metalloproteins or manifesting metal-binding sites. Like all proteomes, a metalloproteome is determined within the context of a well defined system. It can be ascertained for a single metal or multiple metals in that system. Apart from major technological advances in analytical techniques, recent work has examined metalloproteomes for metals other than copper, notably nickel, zinc and manganese. Given the importance of microbiomes to metabolism, microbial metalloproteomics is a rapidly expanding and promising new field. SUMMARY: Metals play key roles in metabolic processes. Sufficient technological progress has taken place in the past decade to make metalloproteomics an exciting and innovative type of research in nutrition and metabolism. It elucidates how metals contribute to metabolic physiology across the phyla, including in microbes. For humans, it may clarify mechanisms as well as identify informative diagnostic or prognostic biomarkers.

Steatohepatitic hepatocellular Carcinoma:A new approach to classifying morphological subtypes of hepatocellular carcinoma.

Histological subtyping of hepatocellular carcinoma (HCC) is challenging in the presence of histological heterogeneity, where distinctly different morphological patterns are present within the same tumor. Current approaches rely on percent cut-offs. We hypothesized that morphologic intratumor heterogeneity is a non-random biological feature and that incorporating recurrent patterns would improve histological subtyping of HCC. Resected HCC were studied and the overall frequency of morphologic intratumor heterogeneity was 45% in 242 specimens. Steatohepatitic HCC (SH-HCC) had the highest frequency of morphologic intratumor heterogeneity (91%); this was confirmed in additional cohorts of SH-HCC from different medical centers (overall frequency of 78% in SH-HCC). Morphologic intratumor heterogeneity in SH-HCC showed distinct and recurrent patterns that could be classified as early, intermediate, and advanced. Incorporating these patterns into the definition of SH-HCC allowed successful resolution of several persistent challenges: the problem of the best cut-off for subtyping SH-HCC, the problem of the relationship between SH-HCC and scirrhous HCC, and the classification for HCC with abundant microvesicular steatosis. This approach also clarified the relationship between SH-HCC and CTNNB1 mutations, showing that CTNNB1 mutations occur late in a subset of SH-HCC. In summary, there is a high frequency of morphologic intratumor heterogeneity in HCC. Incorporating this finding into histological subtyping resolved several persistent problems with the SH-HCC subtype.

NASPGHAN practice guidelines: Diagnosis and management of hepatitis C infection in infants, children, and adolescents.

Hepatitis C virus (HCV) is an RNA virus that affects >180 million individuals worldwide with a high propensity for chronic infection. Children with HCV infection differ from adults in several ways including some modes of transmission, rates of clearance, progression of fibrosis, and the duration of potential chronic infection when acquired at birth. Since the discovery of HCV in 1989, there have been significant advances in the understanding of the virology and natural history of chronic HCV infection in children. In addition, there are now several treatment options for children with chronic hepatitis C infection and many new therapies on the horizon. As a consequence, the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition brought together experts in pediatric hepatology to review the available data in children and provide clinicians with approaches to the diagnosis, management, and prevention of HCV infection in children and adolescents. The guideline details the epidemiology and natural history of HCV infection in children, the diagnostic workup, monitoring and treatment of disease, and provides an update on future treatment options and areas of research.

Autoimmune hepatitis from the paediatric perspective.

Autoimmune hepatitis (AIH) is an important entity within the broad spectrum of autoimmune hepatobiliary disease comprised of AIH, primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Since the 1960s, AIH has been investigated with extensive clinical research aimed at effective therapeutic intervention. It was one of the first liver diseases where treatment was demonstrated to prolong survival. AIH occurs in children, as well as in adults. Its clinical manifestations in children may differ from classic adult AIH. These differences have elucidated certain aspects of AIH and hepatobiliary disease in general. There are two major patterns of AIH: type 1, with anti-smooth muscle antibodies and type 2, with anti-liver/kidney microsomal antibodies. The second type of AIH was first identified in children and is more common in younger patients. AIH often presents as acute disease in children and also in adults: the nomenclature has dropped the allusion to chronicity. Some children who have sclerosing cholangitis present with clinical disease closely resembling AIH; this AIH-like PSC, termed autoimmune sclerosing cholangitis (ASC), is also found in adults. Children with AIH may have identifiable monogenic disorders of immune regulation such as autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Like adults with AIH, children with AIH usually respond very favourably to immunosuppressive treatment with corticosteroids ± azathioprine. True cures seem to be rare, although many children achieve a stable remission. Nonetheless children with AIH may develop cirrhosis and some require liver transplantation. Early diagnosis and improved treatment strategies may further improve the outlook for children with AIH.

Biliary atresia with associated structural malformations in Canadian infants.

BACKGROUND: Biliary atresia (BA) is associated with extrahepatic congenital malformations in a minority of affected infants. The term commonly applied to this subgroup is 'BASM' for biliary atresia splenic malformation syndrome, as spleen abnormalities are prominent. AIMS AND METHODS: To examine clinical outcome in Canadian BA patients with extrahepatic congenital malformations in the Canada-wide BA database of patients born between 1985 and 2002, and additionally, to recharacterized the syndrome. Patients had ≥1 of the following: a/polysplenia, abnormal abdominal situs, intestinal malrotation, abdominal vascular anomaly or congenital heart disease. RESULTS: Among 328 BA patients, 44 (13%) had associated congenital abnormalities. Intra-abdominal anomalies included polysplenia (n=25), abnormal abdominal situs (n=9), intestinal malrotation (n=19), portal vein anomaly (n=12), hepatic artery anomaly (n=3) and inferior vena cava interruption (n=20). Twenty-six patients had cardiac malformations including pulmonary stenosis (n=11), ventricular septal defect (n=10), atrial septal defect (n=7), total anomalous pulmonary venous return (n=3), double outlet right ventricle (n=3), tetralogy of Fallot (n=2), atrioventricular canal (n=2), dextrocardia (n=2), bicuspid aortic valve (n=2), hypoplastic left heart (n=1) and partial anomalous pulmonary venous return (n=1). Age at Kasai operation, performance of liver transplant, overall survival, post-Kasai native liver survival and transplant survival were comparable to isolated BA. Presence of polysplenia or complex cardiac disease did not reduce post-Kasai native liver survival. Three patients had ≥2 typical abnormalities without polysplenia: thus, splenic malformations are not essential to this BA subgroup. Hierarchical cluster analysis demonstrated characteristic abnormalities grouped in a multiplicity of combinations, consistent with a spectrum of defective lateralization. CONCLUSION: We suggest that the acronym 'BASM' be redefined as 'biliary atresia structural malformation'.