Histopathology of pediatric nonalcoholic fatty liver disease

From Childhood Obesity to Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and Hyperlipidemia Through Oxidative Stress During Childhood

BACKGROUND/OBJECTIVES

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is rapidly becoming the most prevalent form of chronic liver disease in both pediatric and adult populations. It encompasses a wide spectrum of liver abnormalities, ranging from simple fat accumulation to severe conditions such as inflammation, fibrosis, cirrhosis, and liver cancer. Major risk factors for MASLD include obesity, insulin resistance, type 2 diabetes, and hypertriglyceridemia.

METHODS

This narrative review employed a comprehensive search of recent literature to identify the latest studies on the relationship between MAFLD and obesity, the health consequences and the latest treatment options to prevent long-term damage to the liver and other organs. Additionally, the article presents perspectives on diagnostic biomarkers.

RESULTS

Childhood obesity is linked to a multitude of comorbid conditions and remains a primary risk factor for adult obesity. This abnormal fat accumulation is known to have long-term detrimental effects into adulthood. Scientific evidence unequivocally demonstrates the role of obesity-related conditions, such as insulin resistance, dyslipidemia, and hyperglycemia, in the development and progression of MASLD. Oxidative stress, stemming from mitochondrial dysfunction, is a leading factor in MASLD. This review discusses the interconnections between oxidative stress, obesity, dyslipidemia, and MASLD.

CONCLUSIONS

Atherogenic dyslipidemia, oxidative stress, inflammation, insulin resistance, endothelial dysfunction, and cytokines collectively contribute to the development of MASLD. Potential treatment targets for MASLD are focused on prevention and the use of drugs to address obesity and elevated blood lipid levels.

Long-term mortality and extrahepatic outcomes in 1096 children with MASLD: A retrospective cohort study

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease in children, but its long-term outcomes are poorly understood. This study aimed to quantify mortality rates, identify causes of death, and evaluate the incidence of cirrhosis and extrahepatic outcomes in children with pediatric-onset MASLD.

APPROACH AND RESULTS

The Longitudinal InVestigation Evaluating Results of Steatosis (LIVERS) study is a single-center, retrospective cohort study conducted at Rady Children's Hospital San Diego. We included 1096 children aged 2-18 years who were diagnosed with MASLD between 2000 and 2017 and followed for a mean of 8.5 years. Mortality was ascertained through the National Death Index, and comorbidities were assessed through follow-up research visits and medical records. Overall, 3.4% of children died, yielding a mortality rate of 398 per 100,000 person-years; nearly half of these deaths were liver-related. Male sex and lower HDL levels independently predicted increased mortality risk. The cumulative incidence of cirrhosis was 4.7%. High incidence rates of extrahepatic comorbidities were observed, including dyslipidemia (3664 per 100,000 person-years), hypertension (1901), obstructive sleep apnea (1185), and type 2 diabetes (911).

CONCLUSIONS

Pediatric MASLD is associated with significant premature mortality and a substantial burden of hepatic and extrahepatic comorbidities. These findings highlight the need for timely screening, early intervention, and long-term management strategies to improve outcomes for children with MASLD.

Visceral Adiposity, Anthropometric and Liver Function Indexes for Identifying Metabolic Dysfunction Associated Steatotic Liver Disease (MASLD) in Adolescents with Obesity: Which Performs Better?

Background: Metabolic Dysfunction Associated Steatotic Liver Disease (MASLD) is the accumulation of fat in the liver without excessive alcohol consumption or other known liver diseases. MASLD is the most common liver disease in adolescents with obesity. The aims of this study were as follows: (i) to determine which index (waist circumference BMI, WHtR, VAI, METS-IR, METS-VF, HSI, FLI, or MetS_zscore) best explains the prevalence of MASLD in adolescents with obesity; (ii) to determine whether there was a specific index that was most strongly associated with MASLD; (iii) to assess which liver function indexes were most strongly correlated with MASLD. Methods: A total of 758 adolescents with severe obesity (BMI z-score > 2) admitted at the Division of Auxology, Istituto Auxologico Italiano, IRCCS, Piancavallo-Verbania for a 3-week multidisciplinary body weight reduction program were selected. Anthropometric parameters (stature, body mass, BMI, and waist and hip circumference) were collected, and body composition (lean and fat mass) was determined using the tetrapolar bioimpedance analysis (BIA) technique. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (gamma GT), alkaline phosphatase (ALP), bilirubin, glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), triglycerides (TG), and C-reactive protein (CRP) were measured using standard techniques. MASLD was diagnosed based on abdominal ultrasound results. Results: WHtR (65.76%) was the most sensitive compared with other indexes. The HSI (AUC: 0.67 (0.63-0.71, 95% CI), p-value < 0.05) showed the best performance in predicting MASLD, with the threshold for having MASLD considered at 48.22. The indexes that showed the worst performance in predicting MASLD were the MetS z-score (AUC: 0.56 (0.52-0.60)) and the VAI (AUC: 0.57 (0.52-0.61)). ALT (OR: 2.92 (2.29-3.77); 95% CI) and AST (OR: 2.52 (2.03-3.20)) were the parameters with a stronger correlation with MASLD. Conclusions: The most sensitive index for diagnosing MASLD was the WHtR, based exclusively on anthropometric parameters. HSI was the index that correlated the most with MASLD, while the parameters of liver function (ALT and AST) were the most strongly correlated with the disease and its severity.

Metabolic dysfunction-associated steatotic liver disease in children

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, is the most common cause of chronic liver disease in children. MASLD encompasses a spectrum of liver disease and can be severe, with 10% of affected children presenting with advanced fibrosis. While biopsy remains the most accurate method for diagnosing and staging the disease, MRI proton density fat fraction and magnetic resonance elastography are the most reliable non-invasive measures for assessing steatosis and fibrosis, respectively. MASLD is associated with multiple comorbidities including type 2 diabetes, hypertension, dyslipidaemia, decreased bone mineral density, obstructive sleep apnoea, anxiety and depression. Currently, there are no pharmacological treatments available for children, highlighting the urgent need for paediatric clinical trials. A diet low in free sugars is promising for reducing steatosis and decreasing alanine aminotransferase, a surrogate marker for hepatic inflammation. Emerging data indicate that steatosis can be present in children under 6 years of age, which was previously considered rare. The intricate interplay of genetics may inform future therapeutics and prognostication, with the PNPLA3 gene showing the most evidence for association with the risk and severity of steatotic liver disease and steatohepatitis. MASLD is a complex disease affecting one in ten children and is associated with increased early mortality risk. More dedicated studies are needed in children to advance our understanding of this disease and find effective treatments.

Association of fatty liver with serum gamma-glutamyltransferase and uric acid in obese children in a tertiary care centre

BACKGROUND

Obesity among the young is an emerging health problem with many metabolic changes including liver damage. Our objective was to investigate the association of fatty liver with serum uric acid (UA) and gamma-glutamyltransferase (GGT) in a cohort of obese children in Sri Lanka.

METHODS

A cross-sectional analytical study was conducted among 5-15-year-old obese children (based on WHO 2007 standards). After a 12-hour overnight fast, blood was drawn for glucose, lipid profile, alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin, UA and GGT. Height, weight, waist circumference, blood pressure and fat mass were measured. Ultrasound scan of abdomen was performed to determine fatty liver.

RESULTS

We studied 146 obese children with a mean age (SD) 9.86 (2.1) years. The fatty liver group showed significantly elevated levels (p < 0.05) of UA, oral glucose tolerance test (OGTT), triglycerides (TG), AST, ALT, GGT, insulin resistance (HOMA-IR) and a reduced AST/ALT ratio, compared to the non-fatty liver group. Chi square test showed statistically significant associations between fatty liver and AST, ALT, AST/ALT ratio, HOMA-IR, UA and GGT. With existing cut offs, GGT (> 30 U/L) and UA (> 330 µmol/L) the sensitivity and specificity of GGT in predicting fatty liver was 26.9% and 94.1% respectively while for UA it was 38.5% and 83.8% respectively. A cut-off value of 18.5 U/L (sensitivity 76.9% and specificity 52.9%) for GGT, 277µmol/L (sensitivity 70.5% and specificity 57.4%) for UA, 27.5 U/L (sensitivity 70.5%, specificity 51.5%) for AST, 21.5 U/L (sensitivity 80.8% and specificity 61.8%) for ALT, a ratio of 0.99 (sensitivity 77.9% and specificity 55.1%) for AST/ALT and 2.02 (sensitivity 73.2%, specificity 58.5%) for HOMA-IR predicted fatty liver.

CONCLUSION

GGT and UA are associated with fatty liver and these biomarkers can be used to predict fatty liver disease.

Steatotic Liver Disease: Navigating Pathologic Features, Diagnostic Challenges, and Emerging Insights

Steatotic liver disease (SLD) is now used as an overarching category encompassing five subcategories: metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic and alcohol related/associated liver disease (MetALD), alcohol-related/associated liver disease (ALD), SLD with specific etiology, and cryptogenic SLD. This review summarizes foundational and recent advances in the histologic evaluation of SLD, including common pathologic features across all subcategories, distinctions associated with different etiologies, scoring and grading systems, and the evolution of digital pathology techniques for SLD assessment.

A Guinea Pig Model of Pediatric Metabolic Dysfunction-Associated Steatohepatitis: Poor Vitamin C Status May Advance Disease

Background/Objectives: Children and teenagers display a distinct metabolic dysfunction-associated steatohepatitis (MASH) phenotype, yet studies of childhood MASH are scarce and validated animal models lacking, limiting the development of treatments. Poor vitamin C (VitC) status may affect MASH progression and often co-occurs with high-fat diets and related metabolic imbalances. As a regulator of DNA methylation, poor VitC status may further contribute to MASH by regulating gene expression This study investigated guinea pigs-a species that, like humans, depends on vitC in the diet-as a model of pediatric MASH, examining the effects of poor VitC status on MASH hallmarks and global DNA methylation levels. Methods: Sixty-two juvenile guinea pigs were exposed to a high-fat diet for 16 weeks. Results: Juvenile guinea pigs exhibited hepatic histopathology representative of pediatric MASH, confirmed by portal inflammation and fibrosis. Consistent with pediatric MASH, juvenile guinea pigs displayed increased lobular and portal inflammation (p < 0.05 and p < 0.0001, respectively) but less steatosis (p < 0.001) compared to adults. Compared to the controls, the guinea pigs deprived in VitC showed lower body weight (p < 0.01), higher expression of hepatic inflammatory genes (p < 0.05), and a lower global hydroxymethylcytosine to methylcytosine ratio in the high-fat groups (p < 0.05). Conclusions: Our study validates guinea pigs as a model of pediatric MASH and suggests that VitC contributes to an altered gene expression signature through the regulation of DNA hydroxymethylation. We postulate that nutritional co-deficiencies in MASH, such as low VitC, may accelerate disease progression and deserve further attention.

Pediatric Non-Alcoholic Fatty Liver Disease (NAFLD): Trends, Mortality, and Socioeconomic Disparities in the U.S., 1998-2020

BACKGROUND/OBJECTIVES

We aim to describe the changing inpatient epidemiology of NAFLD in the U.S. and identify major risk factors associated with mortality in the disease among hospitalized pediatric patients.

METHODS

Hospitalization data from the 1998-2020 National Inpatient Sample were utilized. ICD-9 and ICD-10 codes were used to identify pediatric patients (age less than 18 years old) with NAFLD, and risk factors for mortality were analyzed by logistic regression.

RESULTS

We identified 68,869 pediatric hospitalizations involving NAFLD. Among those, 970 (1.4%) died during hospitalization. Hospitalization rates have been rapidly increasing from 1998 to 2020 (incidence rate ratio (IRR): 1.07; 95% CI: 1.06-1.07; p < 0.001). There was a significant difference in mortality based on the type of hospital (rural, non-teaching urban, or teaching urban) in pediatric patients with NAFLD (p < 0.05). Coagulopathy was significantly associated with increased odds of mortality, while age ≥ 12 years, diabetes and obesity were associated with decreased odds of mortality (p < 0.05). Sex, race/ethnicity, hepatitis B, hepatitis C, HIV, and IV drug use were not significantly associated with mortality.

CONCLUSIONS

Our study has shown ever increasing hospitalization rates for NAFLD in pediatric populations and well as significant risk factors associated with mortality. Further studies should be performed as more data on this patient population are collected.

Spatial Transcriptomics Reveals the Transcriptomic Signatures in a Mouse Model of Pediatric Metabolic Dysfunction-Associated Steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is considered the progressive form of metabolic dysfunction-associated steatotic liver disease, which is the leading cause of chronic liver disease in children. However, the pathogenesis of pediatric MASH remains poorly understood because of the lack of animal models. In this study, a mouse model of pediatric MASH was developed and its hepatic transcriptomic profile was characterized using spatial transcriptomics technology. C57BL/6J mice were fed a Western diet (WD) along with weekly injections of carbon tetrachloride (CCl4) from the age of 3 weeks and lasting up to 8 weeks. After 5 weeks of feeding, WD + CCl4-treated mice showed significant liver injury without the development of insulin resistance. Histologically, WD + CCl4 induced key features of type 2 MASH, the most common type observed in children, characterized by liver steatosis, portal inflammation, and portal fibrosis. Spatial transcriptomics analysis of liver tissues indicated that cluster 0 in the mouse from the WD + CCl4 group was enriched in pathways associated with lipid metabolism. Further investigation revealed that cytochrome p450 2E1 was the top marker gene of cluster 0, and its expression was increased in the periportal area of mice from the WD + CCl4 group. These findings suggest that this mouse model of pediatric MASH mirrors the histologic features of human MASH, and the up-regulation of cytochrome p450 2E1 may be linked to the disease pathogenesis.

Adipose Tissue Insulin Resistance Correlates with Disease Severity in Pediatric Metabolic Dysfunction-Associated Steatotic Liver Disease: A Prospective Cohort Study

OBJECTIVES

To assess the role of adipose tissue insulin resistance (Adipo-IR) in the pathogenesis of pediatric metabolic dysfunction-associated steatotic liver disease (MASLD) and to determine Adipo-IR evolution during a lifestyle intervention program.

STUDY DESIGN

In this prospective cohort study, children and adolescents with severe obesity were recruited between July 2020 and December 2022 at an inpatient pediatric rehabilitation center. Treatment consisted of dietary intervention and physical activity. Liver steatosis and fibrosis were evaluated using ultrasound examination and transient elastography with controlled attenuation parameter and liver stiffness measurement. Every 4-6 months, anthropometric measurements, serum biochemical analysis, ultrasound examination, and elastography were repeated. Adipo-IR was estimated by the product of the fasting serum insulin times the fasting free fatty acid concentration, and hepatic IR by the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), respectively.

RESULTS

Of 200 patients with obesity, 56% had evidence of steatosis on ultrasound examination and 26% were diagnosed with fibrosis (≥F2). Adipo-IR increased progressively from lean controls to patients with obesity to patients with MASLD and MASLD with fibrosis. Adipo-IR was already increased in patients with only mild steatosis (P = .0403). Patients with more insulin-sensitive adipose tissue exhibited a lower liver fat content (P < .05) and serum alanine transaminase levels (P = .001). Adipo-IR correlated positively with visceral adipose tissue weight, waist circumference, and the visceral adipose tissue/gynoid adipose tissue ratio (P < .001), but not with total body fat percentage (P = .263). After 4-6 months of lifestyle management, both MASLD and Adipo-IR improved.

CONCLUSIONS

Our data suggest that Adipo-IR is associated with the presence of pediatric MASLD, particularly steatosis.

Triglyceride Glucose Index is Associated with Ultrasonographic Fatty Liver Indicator in Children and Adolescents with Non-alcoholic Fatty Liver Disease

Objective

Non-alcoholic fatty liver disease (NAFLD) is defined as chronic hepatic steatosis and is becoming prevalent, along with the increasing trend for obesity in children and adolescents. A non-invasive and reliable tool is needed to differentiate non-alcoholic steatohepatitis from simple steatosis. This study evaluated the association between the triglyceride glucose (TyG) index and the ultrasonographic fatty liver indicator (US-FLI), and the possibility of using the TyG index for prediction of severity of pediatric NAFLD.

Methods

One hundred and twenty one patients who were diagnosed with NAFLD by ultrasonography were included. They were categorized into three groups according to body mass index (BMI). Ninety-two were obese, and 19 and 10 were overweight and normal weight, respectively.

Results

The homeostatic model assessment for insulin resistance (HOMA-IR) was highest in the group with obesity (p=0.044). The TyG index and US-FLI did not differ significantly among the three BMI groups (p=0.186). Fourteen (11.6%) of the 121 patients had US-FLI ≥6, in whom the BMI-SDS and TyG index were higher (p=0.017, p=0.004), whereas HOMA-IR did not differ significantly from the group with US-FLI <6 (p=0.366). US-FLI was associated with BMI-SDS and the TyG index. TyG index was significantly associated with US-FLI after adjustment for BMI-SDS. The cut-off value for the TyG index for predicting US-FLI ≥6 was 8.91, with an area under the curve of 0.785.

Conclusion

TyG index was associated with the degree of hepatic steatosis, suggesting that it might be a useful tool for predicting the severity of pediatric NAFLD.

NAFLD (MASLD)/NASH (MASH): Does It Bother to Label at All? A Comprehensive Narrative Review

Nonalcoholic fatty liver disease (NAFLD), or metabolic dysfunction-associated steatotic liver disease (MASLD), is a liver condition that is linked to overweight, obesity, diabetes mellitus, and metabolic syndrome. Nonalcoholic steatohepatitis (NASH), or metabolic dysfunction-associated steatohepatitis (MASH), is a form of NAFLD/MASLD that progresses over time. While steatosis is a prominent histological characteristic and recognizable grossly and microscopically, liver biopsies of individuals with NASH/MASH may exhibit several other abnormalities, such as mononuclear inflammation in the portal and lobular regions, hepatocellular damage characterized by ballooning and programmed cell death (apoptosis), misfolded hepatocytic protein inclusions (Mallory-Denk bodies, MDBs), megamitochondria as hyaline inclusions, and fibrosis. Ballooning hepatocellular damage remains the defining feature of NASH/MASH. The fibrosis pattern is characterized by the initial expression of perisinusoidal fibrosis ("chicken wire") and fibrosis surrounding the central veins. Children may have an alternative form of progressive NAFLD/MASLD characterized by steatosis, inflammation, and fibrosis, mainly in Rappaport zone 1 of the liver acinus. To identify, synthesize, and analyze the scientific knowledge produced regarding the implications of using a score for evaluating NAFLD/MASLD in a comprehensive narrative review. The search for articles was conducted between 1 January 2000 and 31 December 2023, on the PubMed/MEDLINE, Scopus, Web of Science, and Cochrane databases. This search was complemented by a gray search, including internet browsers (e.g., Google) and textbooks. The following research question guided the study: "What are the basic data on using a score for evaluating NAFLD/MASLD?" All stages of the selection process were carried out by the single author. Of the 1783 articles found, 75 were included in the sample for analysis, which was implemented with an additional 25 articles from references and gray literature. The studies analyzed indicated the beneficial effects of scoring liver biopsies. Although similarity between alcoholic steatohepatitis (ASH) and NASH/MASH occurs, some patterns of hepatocellular damage seen in alcoholic disease of the liver do not happen in NASH/MASH, including cholestatic featuring steatohepatitis, alcoholic foamy degeneration, and sclerosing predominant hyaline necrosis. Generally, neutrophilic-rich cellular infiltrates, prominent hyaline inclusions and MDBs, cholestasis, and obvious pericellular sinusoidal fibrosis should favor the diagnosis of alcohol-induced hepatocellular injury over NASH/MASH. Multiple grading and staging methods are available for implementation in investigations and clinical trials, each possessing merits and drawbacks. The systems primarily used are the Brunt, the NASH CRN (NASH Clinical Research Network), and the SAF (steatosis, activity, and fibrosis) systems. Clinical investigations have utilized several approaches to link laboratory and demographic observations with histology findings with optimal platforms for clinical trials of rapidly commercialized drugs. It is promising that machine learning procedures (artificial intelligence) may be critical for developing new platforms to evaluate the benefits of current and future drug formulations.

Renal impairment is prevalent in pediatric NAFLD/MASLD and associated with disease severity

OBJECTIVES

Renal impairment is prevalent in adults with nonalcoholic fatty liver disease (NAFLD/metabolic dysfunction associated steatotic liver disease [MASLD]) and is associated with increased mortality. Pediatric data are limited. Our objective was to determine the prevalence of hyperfiltration or chronic kidney disease (CKD) in children with NAFLD/MASLD and determine links with liver disease severity.

METHODS

Data from children who had previously participated in prospective, multicenter, pediatric studies by the Nonalcoholic Steatohepatitis Clinical Research Network (NASH-CRN) were collected. Renal function was determined using the calculated glomerular filtration rate (cGFR). Hyperfiltration was defined as cGFR > 135 mL/min/1.73m2, while CKD stage 2 or higher as cGFR < 90 mL/min/1.73 m2. Renal dysfunction progression was defined as transition from normal to hyperfiltration or to CKD stage ≥ 2, or change in CKD by ≥1 stage. Multinomial logistic regression models were used to determine the prevalence of CKD and independent associations between CKD and liver disease severity.

RESULTS

The study included 1164 children (age 13 ± 3 years, 72% male, 71% Hispanic). The median cGFR was 121 mL/min/1.73 m2; 12% had CKD stage 2-5, while 27% had hyperfiltration. Hyperfiltration was independently associated with significant liver fibrosis (odds ratio: 1.45). Baseline renal function was not associated with progression in liver disease over a 2-year period (n = 145). Renal dysfunction worsened in 19% independently of other clinical risk factors. Progression of renal impairment was not associated with change in liver disease severity.

CONCLUSIONS

Renal impairment is prevalent in children with NAFLD/MASLD and hyperfiltration is independently associated with significant liver fibrosis. Almost 1/5 children have evidence of progression in renal dysfunction over 2 years, not associated with change in liver disease severity. Future assessments including additional renal impairment biomarkers are needed.

Exosome prospects in the diagnosis and treatment of non-alcoholic fatty liver disease

The growing prevalence of NAFLD and its global health burden have provoked considerable research on possible diagnostic and therapeutic options for NAFLD. Although various pathophysiological mechanisms and genetic factors have been identified to be associated with NAFLD, its treatment remains challenging. In recent years, exosomes have attracted widespread attention for their role in metabolic dysfunctions and their efficacy as pathological biomarkers. Exosomes have also shown tremendous potential in treating a variety of disorders. With increasing evidence supporting the significant role of exosomes in NAFLD pathogenesis, their theragnostic potential has become a point of interest in NAFLD. Expectedly, exosome-based treatment strategies have shown promise in the prevention and amelioration of NAFLD in preclinical studies. However, there are still serious challenges in preparing, standardizing, and applying exosome-based therapies as a routine clinical option that should be overcome. Due to the great potential of this novel theragnostic agent in NAFLD, further investigations on their safety, clinical efficacy, and application standardization are highly recommended.

Serologic Biomarkers for Hepatic Fibrosis in Obese Children with Nonalcoholic Steatohepatitis

Purpose

The prevalence of nonalcoholic steatohepatitis (NASH) is increasing with the increasing prevalence of childhood obesity. Although NASH has a high risk of progression to liver fibrosis and cirrhosis, few studies have reported noninvasive markers for predicting hepatic fibrosis in children. This study aimed to evaluate and compare the diagnostic accuracies of serologic biomarkers and scoring systems for hepatic fibrosis in obese children with NASH.

Methods

A total of 96 children were diagnosed with NASH based on liver biopsy findings and divided into two groups according to the degree of liver fibrosis: mild (stage 0-1) or advanced (stage 2-4). Clinical and laboratory parameters and serum levels of hyaluronic acid and type IV collagen were measured. The aspartate aminotransferase/platelet ratio index (APRI) and fibrosis-4 (FIB-4) score were calculated.

Results

Among the noninvasive markers, only serum type IV collagen level and FIB-4 were significantly different between the two groups. The area under the receiver operating curve of each biomarker and scoring system was 0.80 (95% confidence interval [CI]: 0.70-0.90) for type IV collagen at an optimal cutoff of 148 ng/mL (sensitivity 69.8%, specificity 84.6%), followed by 0.69 (95% CI: 0.57-0.83) for APRI, 0.68 (95% CI: 0.56-0.80) for FIB-4, and 0.65 (95% CI: 0.53-0.77) for hyaluronic acid.

Conclusion

Type IV collagen as a single noninvasive serologic biomarker for hepatic fibrosis and FIB-4 as a hepatic fibrosis score are beneficial in predicting advanced hepatic fibrosis and determining proper diagnosis and treatment strategies before fibrosis progresses in obese children with NASH.

A practical evidence-based approach to management of type 2 diabetes in children and young people (CYP): UK consensus

BACKGROUND

Type 2 diabetes in young people is an aggressive disease with a greater risk of complications leading to increased morbidity and mortality during the most productive years of life. Prevalence in the UK and globally is rising yet experience in managing this condition is limited. There are no consensus guidelines in the UK for the assessment and management of paediatric type 2 diabetes.

METHODS

Multidisciplinary professionals from The Association of Children's Diabetes Clinicians (ACDC) and the National Type 2 Diabetes Working Group reviewed the evidence base and made recommendations using the Grading Of Recommendations, Assessment, Development and Evaluation (GRADE) methodology.

RESULTS AND DISCUSSION

Young people with type 2 diabetes should be managed within a paediatric diabetes team with close working with adult diabetes specialists, primary care and other paediatric specialties. Diagnosis of diabetes type can be challenging with many overlapping features. Diabetes antibodies may be needed to aid diagnosis. Co-morbidities and complications are frequently present at diagnosis and should be managed holistically. Lifestyle change and metformin are the mainstay of early treatment, with some needing additional basal insulin. GLP1 agonists should be used as second-line agents once early ketosis and symptoms are controlled. Glycaemic control improves microvascular but not cardiovascular risk. Reduction in excess adiposity, smoking prevention, increased physical activity and reduction of hypertension and dyslipidaemia are essential to reduce major adverse cardiovascular events.

CONCLUSIONS

This evidence-based guideline aims to provide a practical approach in managing this condition in the UK.

A serum-induced gene signature in hepatocytes is associated with pediatric nonalcoholic fatty liver disease

OBJECTIVE

Pediatric nonalcoholic fatty liver disease (NAFLD) is a growing problem, but its underlying mechanisms are poorly understood. We used transcriptomic reporter cell assays to investigate differences in transcriptional signatures induced in hepatocyte reporter cells by the sera of children with and without NAFLD.

METHODS

We studied serum samples from 45 children with NAFLD and 28 children without NAFLD. The sera were used to induce gene expression in cultured HepaRG cells and RNA-sequencing was used to determine gene expression. Computational techniques were used to compare gene expression patterns.

RESULTS

Sera from children with NAFLD induced the expression of 195 genes that were significantly differentially expressed in hepatocytes compared to controls with obesity. NAFLD was associated with increased expression of genes promoting inflammation, collagen synthesis, and extracellular matrix remodeling. Additionally, there was lower expression of genes involved in endobiotic and xenobiotic metabolism, and downregulation of peroxisome function, oxidative phosphorylation, and xenobiotic, bile acid, and fatty acid metabolism. A 13-gene signature, including upregulation of TREM1 and MMP1 and downregulation of CYP2C9, was consistently associated with all diagnostic categories of pediatric NAFLD.

CONCLUSION

The extracellular milieu of sera from children with NAFLD induced specific gene profiles distinguishable by a hepatocyte reporter system. Circulating factors may contribute to inflammation and extracellular matrix remodeling and impair xenobiotic and endobiotic metabolism in pediatric NAFLD.

Investigating the Relationship Between Rare Genetic Variants and Fibrosis in Pediatric Nonalcoholic Fatty Liver Disease

Background and Aims

Nonalcoholic Fatty Liver Disease (NAFLD) is a complex human disease. Common genetic variation in the patatin-like phospholipase domain containing 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) genes have been associated with an increased risk of developing NAFLD, nonalcoholic steatohepatitis (NASH), and fibrosis in adults. The role of rare genetic variants in the development and progression of NAFLD in children is not well known. We aimed to explore the role of rare genetic variants in pediatric patients with advanced fibrosis.

Methods

Whole exome sequencing data was generated for 229 pediatric patients diagnosed with NAFLD recruited from the NASH Clinical Research Network (NASH CRN). Case-control single variant and gene-based collapsing analyses were used to test for rare variants that were enriched or depleted within the pediatric NAFLD cohort specifically for advanced fibrosis (cases) versus those without fibrosis (controls) or six other histologic characteristics. Exome data from non-NAFLD population controls were also used for additional analyses. All results were adjusted for multiple testing using a Bonferroni correction.

Results

No genome-wide significant associations were found between rare variation and presence of advanced fibrosis or NASH, nor the severity of steatosis, inflammation, or hepatocellular ballooning. Significantly, no enrichment of rare variants in PNPLA3 or TM6SF2 was observed across phenotypes.

Conclusion

In a cohort of children with histologically proven NAFLD, no genome-wide significant associations were found between rare genetic variation and advanced fibrosis or six other histologic features. Of particular interest was the lack of association with genes of interest in adults: PNPLA3 and TM6SF2, though limitations in sample size may reduce the ability to detect associations, particularly with rare variation.

From complement to complosome in non-alcoholic fatty liver disease: When location matters

Non-alcoholic fatty liver disease (NAFLD) is a growing public health threat and becoming the leading cause of liver transplantation. Nevertheless, no approved specific treatment is currently available for NAFLD. The pathogenesis of NAFLD is multifaceted and not yet fully understood. Accumulating evidence suggests a significant role of the complement system in the development and progression of NAFLD. Here, we provide an overview of the complement system, incorporating the novel concept of complosome, and summarise the up-to-date evidence elucidating the association between complement dysregulation and the pathogenesis of NAFLD. In this process, the extracellular complement system is activated through various pathways, thereby directly contributing to, or working together with other immune cells in the disease development and progression. We also introduce the complosome and assess the evidence that implicates its potential influence in NAFLD through its direct impact on hepatocytes or non-parenchymal liver cells. Additionally, we expound upon how complement system and the complosome may exert their effects in relation with hepatic zonation in NAFLD. Furthermore, we discuss the potential therapeutic implications of targeting the complement system, extracellularly and intracellularly, for NAFLD treatment. Finally, we present future perspectives towards a better understanding of the complement system's contribution to NAFLD.

Neutrophils: tissue and circulating signatures of pediatric non-alcoholic fatty liver disease

The recent rise in non-alcoholic fatty liver disease (NAFLD) among children and adolescents led to a thorough investigation of the peculiarities of the cellular infiltrate which characterize the disease at young ages. This review aims to highlight the key involvement of neutrophils in the pathogenesis of pediatric NAFLD and the potential biomarker role of neutrophil-to-lymphocyte ratio (NLR) in the same pediatric disorder. Neutrophils, which are first responders to inflammation, constitute an abundant component of an infiltrate which is particularly disposed within the portal area of children with NAFLD. The involvement of neutrophils in triggering liver fibrosis has been related amongst others to reactive oxygen species (ROS) production, to the stimulation of hepatic stellate cells, and to their synthesis of neutrophil elastase. As immune imbalance characterizes NAFLD, potentially emerging non-invasive biomarkers such as NLR have been proposed for the detection and prognosis of NAFLD. In adults, several studies asserted the role of NLR in the prediction of advancing liver fibrosis and mortality in subjects with NAFLD. In children, data is scarce with contradicting findings, as some studies failed to identify significant shifting in NLR values in children with NAFLD when compared with obese controls without liver impairment. However, NLR seems to significantly increase in children with obesity and different degrees of NAFLD when compared to healthy counterparts and their changes seem to be reversible with weight loss. Still, paucity of pediatric studies calls for future research addressing the role of NLR in predicting NAFLD development and progression in children with obesity.

Wnt-β-catenin in hepatobiliary homeostasis, injury, and repair

Wnt-β-catenin signaling has emerged as an important regulatory pathway in the liver, playing key roles in zonation and mediating contextual hepatobiliary repair after injuries. In this review, we will address the major advances in understanding the role of Wnt signaling in hepatic zonation, regeneration, and cholestasis-induced injury. We will also touch on some important unanswered questions and discuss the relevance of modulating the pathway to provide therapies for complex liver pathologies that remain a continued unmet clinical need.

Updates in Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) in Children

The obesity epidemic is one of the major health concerns of the 21st century. Nonalcoholic fatty liver disease (NAFLD) is linked with the increased adiposity associated with obesity. NAFLD has become the most frequent cause of chronic liver disease in adults and children worldwide. Metabolic dysfunction-associated fatty liver disease (MAFLD) also known in children as pediatric fatty liver disease (PeFLD) type 2 has begun to supersede NAFLD as the preferred nomenclature in the pediatric population. Evidence suggests the etiology of MAFLD is multifactorial, related to the complex interplay of hormonal, nutritional, genetic, and environmental factors. Current limitations in accurate diagnostic biomarkers have rendered it a diagnosis of exclusion and it is important to exclude alternative or coexisting causes of PeFLD. Lifestyle changes and modifications remains the primary treatment modality in MAFLD in children. Weight loss of 7%-10% is described as reversing MAFLD in most patients. The Mediterranean diet also shows promise in reversing MAFLD. Pharmacological intervention is debatable in children, and though pediatric trials have not shown promise, other agents undergoing adult clinical trials show promise. This review outlines the latest evidence in pediatric MAFLD and its management.

Non-alcoholic Fatty Liver in Children and Adolescents in Saudi Arabia

Objectives This study aims to describe the disease parameters of children and adolescents diagnosed with non-alcoholic fatty liver disease (NAFLD) in Saudi Arabia. It also investigates the disease's progression and compares clinical, biochemical, and radiological parameters at baseline and follow-up of patients with NAFLD. This study was done between two groups of patients: obese and those of average body weight.  Methods A retrospective cohort study was conducted between 2014 and 2018 through retrieved data from medical records. It included all children aged between six to 18 years diagnosed with NAFLD. Medical history was taken from each medical record, liver function test results, cholesterol, blood pressure readings, and body weight. Data have been restored from King Abdullah Specialist Children's Hospital (KASCH)​, Security Forces Hospital (SFH), and King Khalid University Hospital (KKUH). Results A total of 116 subjects met the inclusion criteria; 65 (56%) were male, and 81 (70%) were obese. The majority of subjects (n=112) had mild NAFLD, with (71%) obese and (29%) non-obese, followed by moderate NAFLD with 50% among obese and non-obese (N=2), and non-alcoholic steatohepatitis (NASH) with 100% non-obese (N=2). Data showed that patients' proportion of obese to non-obese is 70% (N=81) to 30% (N=35), respectively.  Conclusion NAFLD was found to affect obese children and adolescents more than non-obese, and male patients had a higher proportion of NAFLD than females. Also, obese patients had more advanced stages of NAFLD than non-obese patients. Finally, most subjects had been diagnosed with mild stage while a few had developed NASH.

Review of paediatric obesity and non-alcoholic fatty liver disease-A focus on emerging non-pharmacologic treatment strategies

Obesity in paediatrics has become one of the most serious public health concerns worldwide. Paediatric obesity leads to increased adult obesity and is associated with several comorbidities, both physical and psychological. Within gastroenterology, non-alcoholic fatty liver disease (NAFLD) is now the most common cause of paediatric liver disease and the most common cause of liver transplantation in young adults. Treatment for NAFLD largely focuses on treatment of obesity with weight loss strategies. Unfortunately, the traditional method of weight loss using multicomponent lifestyle modification (dietary changes, increased exercise and behavioural modification) has often led to disappointing results. In adult patients with obesity, treatment strategies have evolved to include bariatric surgery and, more recently, bariatric endoscopy. In paediatrics, the obesity and NAFLD epidemics will likely require this variety of treatment to address children in a personalized manner. Here, we present a review of paediatric obesity, paediatric NAFLD and the various treatment strategies to date. We focus on non-pharmacologic and emerging therapies, including bariatric surgery and bariatric endoscopy-based treatments. With such a large population of children and adolescents with obesity, further development of these treatments, including paediatric-focused clinical trials, is essential for these emerging modalities.

Effects of Early Life Oral Arsenic Exposure on Intestinal Tract Development and Lipid Homeostasis in Neonatal Mice: Implications for NAFLD Development

BACKGROUND

Newborns can be exposed to inorganic arsenic (iAs) through contaminated drinking water, formula, and other infant foods. Epidemiological studies have demonstrated a positive association between urinary iAs levels and the risk of developing nonalcoholic fatty liver disease (NAFLD) among U.S. adolescents and adults.

OBJECTIVES

The present study examined how oral iAs administration to neonatal mice impacts the intestinal tract, which acts as an early mediator for NAFLD.

METHODS

Neonatal mice were treated with a single dose of iAs via oral gavage. Effects on the small intestine were determined by histological examination, RNA sequencing, and biochemical analysis. Serum lipid profiling was analyzed by fast protein liquid chromatography (FPLC), and hepatosteatosis was characterized histologically and biochemically. Liver X receptor-alpha (LXR α ) knockout (L x r α - / - ) mice and liver-specific activating transcription factor 4 (ATF4)-deficient (A t f 4 Δ H e p ) mice were used to define their roles in iAs-induced effects during the neonatal stage.

RESULTS

Neonatal mice exposed to iAs via oral gavage exhibited accumulation of dietary fat in enterocytes, with higher levels of enterocyte triglycerides and free fatty acids. These mice also showed accelerated enterocyte maturation and a longer small intestine. This was accompanied by higher levels of liver-derived very low-density lipoprotein and low-density lipoprotein triglycerides, and a lower level of high-density lipoprotein cholesterol in the serum. Mice exposed during the neonatal period to oral iAs also developed hepatosteatosis. Compared with the control group, iAs-induced fat accumulation in enterocytes became more significant in neonatal L x r α - / - mice, accompanied by accelerated intestinal growth, hypertriglyceridemia, and hepatosteatosis. In contrast, regardless of enterocyte fat accumulation, hepatosteatosis was largely reduced in iAs-treated neonatal A t f 4 Δ H e p mice.

CONCLUSION

Exposure to iAs in neonatal mice resulted in excessive accumulation of fat in enterocytes, disrupting lipid homeostasis in the serum and liver, revealing the importance of the gut-liver axis and endoplasmic reticulum stress in mediating iAs-induced NAFLD at an early age. https://doi.org/10.1289/EHP12381.

Abnormal distribution of fat tissue and its association with intestinal failure-associated liver disease in children and adolescents with long-time parenteral nutrition support: A case-control study

BACKGROUND

Patients with intestinal failure (IF) often present with abnormal body composition characterized by high fat mass. However, the distribution of fat and its association with the development of IF-associated liver disease (IFALD) remain unclear. This study aims to investigate the body composition and its relationship with IFALD in older children and adolescents with IF.

METHODS

This retrospective case-control study enrolled patients with IF receiving parenteral nutrition (PN) at Keio University Hospital who initiated PN before the age of 20 years (cases). The control group included patients with abdominal pain, with available computed tomography (CT) scan and anthropometric data. CT scan images of the third lumbar vertebra (L3) were used for body composition analysis and compared between the groups. Liver histology was compared with CT scan findings in IF patients who underwent biopsy.

RESULTS

Nineteen IF patients and 124 control patients were included. To account for age distribution, 51 control patients were selected. The median skeletal muscle index was 33.9 (29.1-37.3) in the IF group and 42.1 (39.1-45.7) in the control group (P < 0.01). The median visceral adipose tissue index (VATI) was 9.6 (4.9-21.0) in the IF group and 4.6 (3.0-8.3) in the control group (P = 0.018). Among the 13 patients with IF who underwent liver biopsies, 11 (84.6%) had steatosis, and there was a tendency for fibrosis to correlate with VATI.

CONCLUSION

Patients with IF exhibit low skeletal muscle mass and high visceral fat, which may be related to liver fibrosis. Routine monitoring of body composition is recommended.

An Open Label, Randomized, Multicenter Study of Elafibranor in Children With Nonalcoholic Steatohepatitis

OBJECTIVES

Nonalcoholic fatty liver disease is the most common chronic liver disease in children. Elafibranor, a dual peroxisome proliferator-activated receptor α/δ agonist, has been proposed as a treatment for nonalcoholic steatohepatitis (NASH). The aims were to (1) describe pharmacokinetics (PK), safety, and tolerability of oral elafibranor at 2 doses (80 and 120 mg) in children 8-17 years and (2) assess changes in aminotransferases.

METHODS

Children with NASH were randomized to open-label elafibranor 80 mg or 120 mg daily for 12 weeks. The intent-to-treat analysis included all participants who received at least 1 dose. Standard descriptive statistics and PK analyses were performed.

RESULTS

Ten males [mean 15.1 years, standard deviation (SD) 2.2] with NASH were randomized to 80 mg (n = 5) or 120 mg (n = 5). Baseline mean alanine aminotransferase (ALT) was 82 U/L (SD 13) and 87 U/L (SD 20) for 80 mg and 120 mg groups, respectively. Elafibranor was rapidly absorbed and well tolerated. Elafibranor plasma exposure increased between the 80 mg and 120 mg dose with a 1.9- and 1.3-fold increase in median Cmax and AUC 0-24 , respectively. End of treatment mean ALT was 52 U/L (SD 20) for the 120 mg group, with a relative mean ALT change from baseline of -37.4% (SD 23.8%) at 12 weeks.

CONCLUSIONS

Once daily dosing of elafibranor was well tolerated in children with NASH. There was a 37.4% relative reduction from mean baseline ALT in the 120 mg group. Decreasing ALT may be associated with improvement in liver histology, thus could be considered a surrogate for histology in early phase trials. These results may support further exploration of elafibranor in children with NASH.

Feeding medium-chain fatty acid-rich formula causes liver steatosis and alters hepatic metabolism in neonatal pigs

Medium-chain fatty acids (MCFA) and long-chain fatty acids (LCFAs) are often added to enhance the caloric value of infant formulas. Evidence suggests that MCFAs promote growth and are preferred over LCFAs due to greater digestibility and ease of absorption. Our hypothesis was that MCFA supplementation would enhance neonatal pig growth to a greater extent than LCFAs. Neonatal pigs (n = 4) were fed a low-energy control (CONT) or two isocaloric high-energy formulas containing fat either from LCFAs, or MCFAs for 20 days. Pigs fed the LCFAs had greater body weight compared with CONT- and MCFA-fed pigs (P < 0.05). In addition, pigs fed the LCFAs and MCFAs had more body fat than those in the CONT group. Liver and kidney weights as a percentage of body weight were greater (P ≤ 0.05) for pigs fed the MCFAs than those fed the CONT formula, and in those fed LCFAs, liver and kidney weights as a percentage of body weight were intermediate (P ≤ 0.05). Pigs in the CONT and LCFA groups had less liver fat (12%) compared with those in the MCFA (26%) group (P ≤ 0.05). Isolated hepatocytes from these pigs were incubated in media containing [13C]tracers of alanine, glucose, glutamate, and propionate. Our data suggest alanine contribution to pyruvate is less in hepatocytes from LCFA and MCFA pigs than those in the CONT group (P < 0.05). These data suggest that a formula rich in MCFAs caused steatosis compared with an isocaloric LCFA formula. In addition, MCFA feeding can alter hepatocyte metabolism and increase total body fat without increasing lean deposition.NEW & NOTEWORTHY Our data suggest that feeding high-energy MCFA formula resulted in hepatic steatosis compared with isoenergetic LCFA or low-energy formulas. Steatosis coincided with greater laurate, myristate, and palmitate accumulation, suggesting elongation of dietary laurate. Data also suggest that hepatocytes metabolized alanine and glucose to pyruvate, but neither entered the tricarboxylic acid (TCA) cycle. In addition, the contribution of alanine and glucose was greater for the low-energy formulas compared with the high-energy formulas.

Problems and Challenges Associated with Renaming Non-alcoholic Fatty Liver Disease to Metabolic Associated Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has become the world’s largest chronic liver disease in the 21st century, affecting 20%–30% of the world’s population. As the epidemiology, etiology, and pathogenesis of NAFLD have been studied in-depth, it has been gradually recognized that most patients with NAFLD have one or more combined metabolic abnormalities known as metabolic syndrome. In 2020, the international expert group changed the name of NAFLD to metabolic-associated fatty liver disease (MAFLD) and proposed new diagnostic criteria for MAFLD and MAFLD-related liver cirrhosis, as well as the conceptual framework of other cause-related fatty liver diseases to avoid diagnosis based on the exclusion of other causes and better reflect its pathogenesis. However, there are still many ambiguities in the term, and changing the name does not address the unmet key needs in the field. The change from NAFLD to MAFLD was not just a change of definition. The problems and challenges are summarized as follows: epidemiology, children, rationality of “metabolism,” diagnostic criteria, double/multiple causes, drug discovery, clinical trials, and awareness raising. Metabolic-associated fatty liver disease has complex disease characteristics, and there are still some problems that need to be solved.

Role of Liver Biopsy in Clinical Trials and Clinical Management of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis constitute a spectrum of histologic lesions characterized by varying degrees of hepatocellular injury and fat accumulation with inflammation and scarring. Fibrosis associated with this disease may progress to cirrhosis and its complications. As there are no approved therapies, clinical trials to assess potential forms of drug therapy are conducted to assess drugs for efficacy and safety before submission to regulatory review. Liver biopsies are performed and evaluated to confirm the diagnosis of nonalcoholic steatohepatitis and to assess fibrosis stage for inclusion in trials.

Special Population: Pediatric Nonalcoholic Fatty Liver Disease

Pediatric nonalcoholic fatty liver disease represents the most common liver disease in children and has been shown to carry significant morbidity. Widespread heterogeneity of disease, as well as the limitation of indirect screening modalities, has made true prevalence of disease difficult to estimate as well as hindered ability to identify optimal prognostic factors in the pediatric population. Current therapeutic options are limited in pediatric patients with current mainstay of therapy, lifestyle modifications, has proven to have a limited efficacy in current clinical application. Current research remains needed in improved screening modalities, prognosticating techniques, and therapeutic options in the pediatric population.

A Spatial Atlas of Wnt Receptors in Adult Mouse Liver

Hepatic zonation is critical for most metabolic functions in liver. Wnt signaling plays an important role in establishing and maintaining liver zonation. Yet, the anatomic expression of Wnt signaling components, especially all 10 Frizzled (Fzd) receptors, has not been characterized in adult liver. To address this, the spatial expression of Fzd receptors was quantitatively mapped in adult mouse liver via multiplex fluorescent in situ hybridization. Although all 10 Fzd receptors were expressed within a metabolic unit, Fzd receptors 1, 4, and 6 were the highest expressed. Although most Wnt signaling occurs in zone 3, expression of most Fzd receptors was not zonated. In contrast, Fzd receptor 6 was preferentially expressed in zone 1. Wnt2 and Wnt9b expression was highly zonated and primarily found in zone 3. Therefore, the current results suggest that zonated Wnt/β-catenin signaling at baseline occurs primarily due to Wnt2 and Wnt9b rather than zonation of Fzd mRNA expression. Finally, the study showed that Fzd receptors and Wnts are not uniformly expressed by all hepatic cell types. Instead, there is broad distribution among both hepatocytes and nonparenchymal cells, including endothelial cells. Overall, this establishment of a definitive mRNA expression atlas, especially of Fzd receptors, opens the door to future functional characterization in healthy and diseased liver states.

Postprandial triglycerides and fibroblast growth factor 19 as potential screening tools for paediatric non-alcoholic fatty liver disease

BACKGROUND

Better screening tools for paediatric NAFLD are needed. We tested the hypothesis that the postprandial triglyceride (TG) and fibroblast growth factor 19 (FGF19) response to an abbreviated fat tolerance test (AFTT) could differentiate adolescents with NAFLD from peers with obesity and normal weight.

METHODS

Fifteen controls with normal weight (NW), 13 controls with obesity (OB) and 9 patients with NAFLD completed an AFTT. Following an overnight fast, participants consumed a high-fat meal. TG and FGF19 were measured at baseline and 4 h post-meal. Liver steatosis and fibrosis were measured via Fibroscan.

RESULTS

Fasting TG and FGF19 did not differ among groups; 4 h TG in the NAFLD and OB groups were greater (197 ± 69 mg/dL; 157 ± 72 mg/dL, respectively) than NW (105 ± 45 mg/dL; p < 0.05) and did not differ from one another. Within the entire cohort, 4 h TG were stratified by high and low steatosis. Adolescents with high steatosis had 98% greater 4 h TG than adolescents with low steatosis. 4 h FGF19, but not fasting FGF19, was higher in children with low steatosis compared with high steatosis (p < 0.05). Using area under the receiver operating curve (AUROC), the only biochemical outcome with diagnostic accuracy for NAFLD was 4 h TG (0.77 [95% CI: 0.60-0.94; p = 0.02]).

CONCLUSIONS

The postprandial TG response is increased in adolescents with obesity with hepatic steatosis, with or without NAFLD. Our preliminary analysis demonstrates 4 h TG differentiate patients with NAFLD from those without, supporting a role for the AFTT as a screening tool for paediatric NAFLD.

Liver fibrosis in children: a comprehensive review of mechanisms, diagnosis, and therapy

Chronic liver disease incidence is increasing among children worldwide due to a multitude of epidemiological changes. Most of these chronic insults to the pediatric liver progress to fibrosis and cirrhosis to different degrees. Liver and immune physiology differs significantly in children from adults. Because most of pediatric liver diseases have no definitive therapy, a better understanding of population and disease-specific fibrogenesis is mandatory. Furthermore, fibrosis development has prognostic significance and often guide treatment. Evaluation of liver fibrosis continues to rely on the gold-standard liver biopsy. However, many high-quality studies put forward the high diagnostic accuracy of numerous diagnostic modalities in this setting. Herein, we summarize and discuss the recent literature on fibrogenesis with an emphasis on pediatric physiology along with a detailed outline of disease-specific signatures, noninvasive diagnostic modalities, and the potential for antifibrotic therapies.

Cardiovascular disease risk in paediatric and young adult non-alcoholic fatty liver disease

OBJECTIVE

Longitudinal evidence is lacking regarding the long-term risk of major adverse cardiovascular events (MACE) in children and young adults with non-alcoholic fatty liver disease (NAFLD).

DESIGN

This nationwide cohort study included all Swedish children and young adults ≤25 years old with histologically confirmed NAFLD and without underlying cardiovascular disease (CVD) at baseline (1966-2016; n=699). NAFLD was defined from prospectively recorded histopathology, and further categorised as simple steatosis or non-alcoholic steatohepatitis (NASH). NAFLD patients were matched to ≤5 population controls without NAFLD or CVD (n=3353). Using Cox proportional hazards modelling, we calculated multivariable-adjusted HRs (aHRs) and 95% CIs for incident MACE (ie, ischaemic heart disease, stroke, congestive heart failure or cardiovascular mortality). In secondary analyses, we also explored rates of incident cardiac arrhythmias.

RESULTS

Over a median follow-up of 16.6 years, incident MACE was confirmed in 33 NAFLD patients and 52 controls. NAFLD patients had significantly higher rates of MACE than controls (3.1 vs 0.9/1000 person-years (PY); difference=2.1/1000 PY; aHR=2.33, 95% CI=1.43 to 3.78), including higher rates of ischaemic heart disease (difference=1.4/1000 PY; aHR=3.07, 95% CI 1.62 to 5.83) and congestive heart failure (difference=0.5/1000 PY; aHR=3.89, 95% CI=1.20 to 12.64). Rates of incident MACE outcomes appeared to be further augmented with NASH (aHR=5.27, 95% CI=1.96 to 14.19). In secondary analyses, NAFLD patients also had significantly higher rates of cardiac arrythmias (aHR=3.16, 95% CI=1.49 to 6.68).

CONCLUSION

Compared with matched population controls, children and young adults with biopsy-proven NAFLD had significantly higher rates of incident MACE, including ischaemic heart disease and congestive heart failure. Research to better characterise cardiovascular risk in children and young adults with NAFLD should be prioritised.

Metabolic-Associated Fatty Liver Disease in Childhood and Adolescence

Metabolic-associated fatty liver disease (MAFLD) has become the most common cause for chronic liver disease among children and adolescents globally. Although liver biopsy remains the gold standard for diagnosis, emerging technology, like velocity controlled transient elastography, a noninvasive method, is being utilized to evaluate degree of fibrosis in these patients. The discovery of multiple gene polymorphisms has brought new hope for possible treatment targets. However, this research is still ongoing, making lifestyle changes and weight reduction the current mainstay of treatment. This review briefly reviews the most recent data regarding the epidemiology, pathophysiology, diagnostic modalities, and treatment of pediatric MAFLD.

Maternal Western diet is associated with distinct preclinical pediatric NAFLD phenotypes in juvenile nonhuman primate offspring

Pediatric NAFLD has distinct and variable pathology, yet causation remains unclear. We have shown that maternal Western-style diet (mWSD) compared with maternal chow diet (CD) consumption in nonhuman primates produces hepatic injury and steatosis in fetal offspring. Here, we define the role of mWSD and postweaning Western-style diet (pwWSD) exposures on molecular mechanisms linked to NAFLD development in a cohort of 3-year-old juvenile nonhuman primates offspring exposed to maternal CD or mWSD followed by CD or Western-style diet after weaning. We used histologic, transcriptomic, and metabolomic analyses to identify hepatic pathways regulating NAFLD. Offspring exposed to mWSD showed increased hepatic periportal collagen deposition but unchanged hepatic triglyceride levels and body weight. mWSD was associated with a downregulation of gene expression pathways underlying HNF4α activity and protein, and downregulation of antioxidant signaling, mitochondrial biogenesis, and PPAR signaling pathways. In offspring exposed to both mWSD and pwWSD, liver RNA profiles showed upregulation of pathways promoting fibrosis and endoplasmic reticulum stress and increased BiP protein expression with pwWSD. pwWSD increased acylcarnitines and decreased anti-inflammatory fatty acids, which was more pronounced when coupled with mWSD exposure. Further, mWSD shifted liver metabolites towards decreased purine catabolism in favor of synthesis, suggesting a mitochondrial DNA repair response. Our findings demonstrate that 3-year-old offspring exposed to mWSD but weaned to a CD have periportal collagen deposition, with transcriptional and metabolic pathways underlying hepatic oxidative stress, compromised mitochondrial lipid sensing, and decreased antioxidant response. Exposure to pwWSD worsens these phenotypes, triggers endoplasmic reticulum stress, and increases fibrosis. Overall, mWSD exposure is associated with altered expression of candidate genes and metabolites related to NAFLD that persist in juvenile offspring preceding clinical presentation of NAFLD.

Non-alcoholic fatty liver disease: the pathologist's perspective

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of diseases characterized by fatty accumulation in hepatocytes, ranging from steatosis, non-alcoholic steatohepatitis, to cirrhosis. While histopathological evaluation of liver biopsies plays a central role in the diagnosis of NAFLD, limitations such as the problem of interobserver variability still exist and active research is underway to improve the diagnostic utility of liver biopsies. In this article, we provide a comprehensive overview of the histopathological features of NAFLD, the current grading and staging systems, and discuss the present and future roles of liver biopsies in the diagnosis and prognostication of NAFLD.

Relative Enhancement in Gadoxetate Disodium-Enhanced Liver MRI as an Imaging Biomarker in the Diagnosis of Non-Alcoholic Fatty Liver Disease in Pediatric Obesity

Relative enhancement (RE) in gadoxetate disodium (Gd-EOB-DTPA)-enhanced MRI is a reliable, non-invasive method for the evaluation and differentiation between simple steatosis and non-alcoholic steatohepatitis in adults. This study evaluated the diagnostic accuracy of RE in Gd-EOB-DTPA-enhanced liver MRI and hepatic fat fraction (HFF) in unenhanced liver MRI and ultrasound (US) for non-alcoholic fatty liver disease (NAFLD) screening in pediatric obesity. Seventy-four liver US and MRIs from 68 pediatric patients (13.07 ± 2.95 years) with obesity (BMI > BMI-for-age + 2SD) were reviewed with regard to imaging biomarkers (liver size, volume, echogenicity, HFF, and RE in Gd-EOB-DTPA-enhanced MRIs, and spleen size), blood biomarkers, and BMI. The agreement between the steatosis grade, according to HFF in MRI and the echogenicity in US, was moderate. Alanine aminotransferase correlated better with the imaging biomarkers in MRI than with those in US. BMI correlated better with liver size and volume on MRI than in US. In patients with RE < 1, blood biomarkers correlated better with RE than those in the whole sample, with a significant association between gamma-glutamyltransferase and RE (p = 0.033). In conclusion, the relative enhancement and hepatic fat fraction can be considered as non-invasive tools for the screening and follow-up of NAFLD in pediatric obesity, superior to echogenicity on ultrasound.

Tetrastigma hemsleyanum leaf extracts ameliorate NAFLD in mice with low-grade colitis via the gut-liver axis

Nonalcoholic fatty liver disease (NAFLD) is a complex metabolic disorder, manifested as oxidative stress, lipid accumulation, and inflammation of the liver. Tetrastigma hemsleyanum leaves (THL), which are rich in flavonoids and phenolic acids, have good anti-inflammatory, antioxidant, and hepatoprotective effects. However, it is unknown whether THL extracts can improve NAFLD and the underlying mechanisms are unknown. Hence, this study was designed to investigate the effects of THL extracts on NAFLD and perform a preliminary inquiry into the underlying mechanism based on the gut-liver axis. The results showed that THL extracts could reverse NAFLD-related oxidative stress, lipid accumulation, and inflammation. Additionally, the protective effect of THL extracts on the gut includes the maintenance of the intestinal barrier and the regulation of gut microbiota, which may be one of the mechanisms by which THL improves NAFLD. To be specific, in our study, THL extracts alleviated hepatic lipid accumulation and oxidative stress by regulating the expression of lipid synthesis/catabolism and the oxidative stress genes (SREBP-1c/ACC-1/PPAR-α/PPAR-γ/Keap1/Nrf2). In addition, THL extracts reduced damage to the intestinal barrier (ZO-1/Mucin2/occludin) and increased the relative abundance of Lactobacillales, Ruminococcaceae, and Bifidobacteriales in NAFLD mice. In short, THL extracts alleviated NAFLD-related oxidative stress, lipid accumulation, and inflammation in NAFLD mice which may be via the gut-liver axis (gut barrier integrity and gut microbiota).

Tilianin Protects against Nonalcoholic Fatty Liver Disease in Early Obesity Mice

Non-alcoholic fatty liver disease (NAFLD) has emerged as one of the most frequent types of liver disease in pediatric populations with obesity. Tilianin has multiple biological activities including anti-inflammatory and antioxidant. Here, we aim to explore the functions and possible mechanisms of tilianin on NAFLD in obese children. A high-fat high-carbohydrate (HFHC) diet was used to feed 21-d-old mice. Tilianin was administered at a dose of 10 or 20 mg/kg daily. HFHC-fed mice gained weight, increased liver index. The liver showed hepatocyte ballooning, inflammatory infiltration, and steatosis. Elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) and reduced the high-density lipoprotein cholesterol (HDL-C) level were found in HFHC-fed mice. Administration of tilianin significantly reduced these impairments. We further evaluated proteins related to lipid metabolism and observed that LXRα, SREBP-1c, FAS and ACC1 expression were blunted following tilianin administration. In addition, tilianin suppressed reactive oxygen species (ROS) overproduction and lipid peroxide 4-Hydroxynonenal expression, ascribed to its oxidative stress-modulating capacity. Tilianin also reversed the increase in F4/80 expression and proinflammatory cytokine levels. Of note, tilianin administration resulted in decreased protein levels of active caspase-1 and NOD-like receptor protein 3 (NLRP3) in HFHC-fed mice. Our study suggests that tilianin may ameliorate NAFLD in early obese mice by modulating lipids metabolism, oxidative stress, and inflammation, which may in part involve inhibiting NLRP3 inflammasome activation.

Nonalcoholic fatty liver disease risk and histologic severity are associated with genetic polymorphisms in children

BACKGROUND AND AIMS

NAFLD is the most common chronic liver disease in children. Large pediatric studies identifying single nucleotide polymorphisms (SNPs) associated with risk and histologic severity of NAFLD are limited. Study aims included investigating SNPs associated with risk for NAFLD using family trios and association of candidate alleles with histologic severity.

APPROACH AND RESULTS

Children with biopsy-confirmed NAFLD were enrolled from the NASH Clinical Research Network. The Expert Pathology Committee reviewed liver histology. Genotyping was conducted with allele-specific primers for 60 candidate SNPs. Parents were enrolled for trio analysis. To assess risk for NAFLD, the transmission disequilibrium test was conducted in trios. Among cases, regression analysis assessed associations with histologic severity. A total of 822 children with NAFLD had mean age 13.2 years (SD 2.7) and mean ALT 101 U/L (SD 90). PNPLA3 (rs738409) demonstrated the strongest risk ( p = 2.24 × 10 -14 ) for NAFLD. Among children with NAFLD, stratifying by PNPLA3 s738409 genotype, the variant genotype associated with steatosis ( p = 0.005), lobular ( p = 0.03) and portal inflammation ( p = 0.002). Steatosis grade associated with TM6SF2 ( p = 0.0009), GCKR ( p = 0.0032), PNPLA3 rs738409 ( p = 0.0053), and MTTP ( p = 0.0051). Fibrosis stage associated with PARVB rs6006473 ( p = 0.0001), NR1I2 ( p = 0.0021), ADIPOR2 ( p = 0.0038), and OXTR ( p = 0.0065). PNPLA3 rs738409 ( p = 0.0002) associated with borderline zone 1 NASH.

CONCLUSIONS

This study demonstrated disease-associated SNPs in children with NAFLD. In particular, rs6006473 was highly associated with severity of fibrosis. These hypothesis-generating results support future mechanistic studies of development of adverse outcomes such as fibrosis and generation of therapeutic targets for NAFLD in children.

Screening Patterns of Nonalcoholic Fatty Liver Disease in Children with Obesity in Canadian Primary Care: A Cross-Sectional Study

Background

Nonalcoholic fatty liver disease (NAFLD) is the most common pediatric chronic liver disease, and children with a body mass index (BMI) ≥95th percentile are recommended to be screened for NAFLD by liver enzymes.

Objectives

This study aimed to determine the frequency and predictors of screening for NAFLD among children with obesity in Canada and to evaluate a sample of children with suspected NAFLD.

Methods

This cross-sectional study used data from the Canadian Primary Care Sentinel Surveillance Network, a repository of electronic medical record data from Canadian primary care practices.

Results

Of n = 110,827 children aged 9-18 years, 13.9% (n = 9,888) had a BMI ≥95th percentile. Only 8.7% (n = 859) of these patients were screened for NAFLD in the last year, and 23.6% (n = 2336) were ever screened. Using logistic regression, screening in the last year was associated with demographic and clinical characteristics, including previous liver enzyme assessment, prior antidiabetic prescription, and prior anxiolytic prescription. Among children with suspected NAFLD (n = 1,046), 34.7% had a BMI ≥99th percentile and approximately 8% were at increased risk of significant liver disease.

Conclusion

The study revealed low screening rates for NAFLD in Canadian primary care and highlighted the important role of primary care providers in identifying and managing pediatric NAFLD.

The protective roles of augmenter of liver regeneration in hepatocytes in the non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) occurs in 25% of the global population and manifests as lipid deposition, hepatocyte injury, activation of Kupffer and stellate cells, and steatohepatitis. Predominantly expressed in hepatocytes, the augmenter of liver regeneration (ALR) is a key factor in liver regulation that can alleviate fatty liver disease and protect the liver from abnormal liver lipid metabolism. ALR has three isoforms (15-, 21-, and 23-kDa), amongst which 23-kDa ALR is the most extensively studied. The 23-kDa ALR isoform is a sulfhydryl oxidase that resides primarily in the mitochondrial intermembrane space (IMS), whereby it protects the liver against various types of injury. In this review, we describe the role of ALR in regulating hepatocytes in the context of NAFLD. We also discuss questions about ALR that remain to be explored in the future. In conclusion, ALR appears to be a promising therapeutic target for treating NAFLD.

The Role of the miR-17-92 Cluster in Autophagy and Atherosclerosis Supports Its Link to Lysosomal Storage Diseases

Establishing the role of non-coding RNA (ncRNA), especially microRNAs (miRNAs), in the regulation of cell function constitutes a current research challenge. Two to six miRNAs can act in clusters; particularly, the miR-17-92 family, composed of miR-17, miR-18a, miR-19a, miR-20a, miR-19b-1, and miR-92a is well-characterized. This cluster functions during embryonic development in cell differentiation, growth, development, and morphogenesis and is an established oncogenic cluster. However, its role in the regulation of cellular metabolism, mainly in lipid metabolism and autophagy, has received less attention. Here, we argue that the miR-17-92 cluster is highly relevant for these two processes, and thus, could be involved in the study of pathologies derived from lysosomal deficiencies. Lysosomes are related to both processes, as they control cholesterol flux and regulate autophagy. Accordingly, we compiled, analyzed, and discussed current evidence that highlights the cluster's fundamental role in regulating cellular energetic metabolism (mainly lipid and cholesterol flux) and atherosclerosis, as well as its critical participation in autophagy regulation. Because these processes are closely related to lysosomes, we also provide experimental data from the literature to support our proposal that the miR-17-92 cluster could be involved in the pathogenesis and effects of lysosomal storage diseases (LSD).

Dietary fat composition shapes bile acid metabolism and severity of liver injury in a pig model of pediatric NAFLD

The objective of this study was to investigate the effect of dietary fatty acid (FA) composition on bile acid (BA) metabolism in a pig model of NAFLD, by using a multiomics approach combined with histology and serum biochemistry. Thirty 20-day-old Iberian pigs pair-housed in pens were randomly assigned to receive 1 of 3 hypercaloric diets for 10 wk: 1) lard-enriched (LAR; n = 5 pens), 2) olive oil-enriched (OLI; n = 5), and 3) coconut oil-enriched (COC; n = 5). Animals were euthanized on week 10 after blood sampling, and liver, colon, and distal ileum (DI) were collected for histology, metabolomics, and transcriptomics. Data were analyzed by multivariate and univariate statistics. Compared with OLI and LAR, COC increased primary and secondary BAs in liver, plasma, and colon. In addition, both COC and OLI reduced circulating fibroblast growth factor 19, increased hepatic necrosis, composite lesion score, and liver enzymes in serum, and upregulated genes involved in hepatocyte proliferation and DNA repair. The severity of liver disease in COC and OLI pigs was associated with increased levels of phosphatidylcholines, medium-chain triacylglycerides, trimethylamine-N-oxide, and long-chain acylcarnitines in the liver, and the expression of profibrotic markers in DI, but not with changes in the composition or size of BA pool. In conclusion, our results indicate a role of dietary FAs in the regulation of BA metabolism and progression of NAFLD. Interventions that aim to modify the composition of dietary FAs, rather than to regulate BA metabolism or signaling, may be more effective in the treatment of NAFLD.NEW & NOTEWORTHY Bile acid homeostasis and signaling is disrupted in NAFLD and may play a central role in the development of the disease. However, there are no studies addressing the impact of diet on bile acid metabolism in patients with NAFLD. In juvenile Iberian pigs, we show that fatty acid composition in high-fat high-fructose diets affects BA levels in liver, plasma, and colon but these changes were not associated with the severity of the disease.