Portal inflammation is independently associated with fibrosis and metabolic syndrome in pediatric nonalcoholic fatty liver disease

Analysis of risk factors for fatty liver disease in children with Wilson's disease

BACKGROUND AND AIMS

Many children with Wilson's disease are complicated with dyslipidemia. The aim of this study was to investigate the risk factors for the development of fatty liver disease (FLD) in children with Wilson's disease.

METHODS

We evaluated sex, age, weight, the disease course, treatment course, clinical classification, alanine transaminase (ALT), aspartate transaminase, γ-glutamyl transpeptidase, total biliary acid, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, homocysteine, uric acid, fibrinogen (FBG), creatinine, procollagen III N-terminal propeptide, laminin, hyaluronic acid, type IV collagen, and performed receiver operating characteristic curve analysis to investigate the forecast value of individual biochemical predictors and combined predictive indicators to evaluate FLD in Wilson's disease.

RESULTS

The multivariate logistic regression analysis revealed that ALT [odds ratio (OR), 1.011; 95% confidence interval (CI), 1.004-1.02; P  = 0.006], uric acid (OR, 1.01; 95% CI, 1.002-1.018; P  = 0.017), FBG (OR, 3.668; 95% CI, 1.145-13.71; P  = 0.037), creatinine (OR, 0.872; 95% CI, 0.81-0.925; P  < 0.001), and laminin (OR, 1.01; 95% CI, 1.002-1.018; P  = 0.017) acted as independent risk factors in Wilson's disease complicated with FLD. The receiver operating characteristic curves for combined predictive indicators demonstrated an area under the curve values of 0.872, which was found to be a significant predictors for FLD in Wilson's disease.

CONCLUSIONS

We screened out the most important risk factors, namely ALT, uric acid, creatinine, FBG, and laminin for Wilson's disease complicated with FLD. The joint prediction achieved is crucial for identifying children with Wilson's disease complicated with FLD.

The importance of SII and FIB-4 scores in predicting mortality in idiopathic pulmonary fibrosis patients

INTRODUCTION

Quick and simple parameters are needed to predict mortality in patients with idiopathic pulmonary fibrosis (IPF). In this way, risky patients will have the opportunity to receive early and effective treatment. In this study, we examined whether the Fibrosis-4 index (FIB-4) and systemic immune inflammation index (SII) are associated with mortality in IPF patients.

MATERIALS AND METHODS

The study was designed retrospectively. 100 patients diagnosed with IPF were included in the study. Variables between living patients and deceased patients were examined.

RESULTS

Out of a total of 100 patients, 67 were divided into the surviving group and 33 into the non-surviving group. In multivariate analysis, high FIB-4 and SII values were significantly associated with an increased risk of death.

CONCLUSION

FIB-4 and SII are parameters that can predict mortality in IPF patients. In this way, IPF patients with high mortality risk will be identified earlier and more effective methods will be used in follow-up and treatment.

Paediatric steatotic liver disease has unique characteristics: A multisociety statement endorsing the new nomenclature

Nonalcoholic fatty liver disease (NAFLD) has been a commonly used term and diagnosis in paediatric hepatology, gastroenterology, and endocrinology clinics for over 30 years. A multisociety Delphi process has determined a new name "Steatotic Liver Disease" (SLD) as the overarching term for disorders associated with hepatic lipid accumulation. Our Societies give our support to steatotic liver disease as the best overarching term for use in our communities. Metabolic dysfunction-associated steatotic liver disease (MASLD) overcomes many of the shortcomings of the name NAFLD. Here, we highlight several points of the new nomenclature that are of particular importance for our community and their consequences for implementation including: diagnostic criteria, considering alternate diagnoses, practical implementation, research, advocacy, and education for paediatricians. As with all nomenclature changes, it will take a concerted effort from our paediatric societies to help integrate the optimal use of this into practice.

Noninvasive scores are poorly predictive of histological fibrosis in paediatric fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children. Roughly a quarter of paediatric patients with NAFLD develop nonalcoholic steatohepatitis and fibrosis. Here, we evaluated the diagnostic accuracy of previously published noninvasive fibrosis scores to predict liver fibrosis in a large European cohort of paediatric patients with NAFLD.

METHODS

The 457 patients with biopsy-proven NAFLD from 10 specialized centers were included. We assessed diagnostic accuracy for the prediction of any (F ≥ 1), moderate (F ≥ 2) or advanced (F ≥ 3) fibrosis for the AST/platelet ratio (APRI), Fibrosis 4 score (FIB-4), paediatric NAFLD fibrosis score (PNFS) and paediatric NAFLD fibrosis index (PNFI).

RESULTS

Patients covered the full spectrum of fibrosis (F0: n = 103; F1: n = 230; F2: n = 78; F3: n = 44; F4: n = 2). None of the scores were able to accurately distinguish the presence of any fibrosis from no fibrosis. For the detection of moderate fibrosis, area under the receiver operating characteristic curve (AUROC) were: APRI: 0.697, FIB-4: 0.663, PNFI: 0.515, PNFS: 0.665, while for detection of advanced fibrosis AUROCs were: APRI: 0.759, FIB-4: 0.611, PNFI: 0.521, PNFS: 0.712. Fibrosis scores showed no diagnostic benefit over using ALT ≤ 50/ > 50 IU/L as a cut-off.

CONCLUSIONS

Established fibrosis scores lack diagnostic accuracy to replace liver biopsy for staging of fibrosis, giving similar results as compared to using ALT alone. New diagnostic tools are needed for Noninvasive risk-stratification in paediatric NAFLD.

Quantitative ultrasound fatty liver evaluation in a pediatric population: comparison with magnetic resonance imaging of liver proton density fat fraction

BACKGROUND

Biopsy remains the gold standard for the diagnosis of hepatic steatosis, the leading cause of pediatric chronic liver disease; however, its costs call for less invasive methods.

OBJECTIVE

This study examined the diagnostic accuracy and reliability of quantitative ultrasound (QUS) for the assessment of liver fat content in a pediatric population, using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard.

MATERIALS AND METHODS

We enrolled 36 patients. MRI-PDFF involved a 3-dimensional T2*-weighted with Dixon pulse multiple-echo sequence using iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL IQ). QUS imaging relied on the ultrasound system "RS85 A" (Samsung Medison, Seoul, South Korea) and the following software: Hepato-Renal Index with automated region of interest recommendation (EzHRI), Tissue Attenuation Imaging (TAI), and Tissue Scatter Distribution Imaging (TSI). For each QUS index, receiver operating characteristic (ROC) curve analysis against MRI-PDFF was used to identify the associated cut-off value and the area under the ROC curve (AUROC). Concordance between two radiologists was assessed by intraclass correlation coefficients (ICCs) and Bland-Altman analysis.

RESULTS

A total of 61.1% of the sample (n=22) displayed a MRI-PDFF ≥ 5.6%; QUS cut-off values were TAI=0.625 (AUROC 0.90, confidence interval [CI] 0.77-1.00), TSI=91.95 (AUROC 0.99, CI 0.98-1.00) and EzHRI=1.215 (AUROC 0.98, CI 0.94-1.00). Inter-rater reliability was good-to-excellent for EzHRI (ICC 0.91, 95% C.I. 0.82-0.95) and TAI (ICC 0.94, 95% C.I. 0.88-0.97) and moderate to good for TSI (ICC 0.73; 95% C.I. 0.53-0.85).

CONCLUSION

Our results suggest that QUS can be used to reliably assess the presence and degree of pediatric hepatic steatosis.

Diagnostic Performance of Biomarker-Based Scores as Predictors of Metabolic Dysfunction-Associated Fatty Liver Disease Risk in Healthy Children

INTRODUCTION

Metabolic dysfunction-associated fatty liver disease (MAFLD)-a new definition for non-alcoholic fatty liver disease-reflects the impact of metabolic abnormalities on liver function. We assessed the diagnostic accuracy of biomarker-based scores for prediction of MAFLD in apparently healthy children.

METHODS

This study included 144 children aged 9-11. MAFLD was recognized in 14 girls and 29 boys. Anthropometric indices, glycemia, insulin resistance, lipid profile, enzymes (ALT, AST, GGT, ALP), CRP, N-terminal propeptide of type I procollagen (P1NP) and collagen type I C-telopeptide (CTX-1) levels were measured. Fatty liver and hepatic steatosis index (FLI, HSI) and potential indicators of liver fibrogenesis: P1NP/ALP, P1NP/ALPxALT, P1NP/ALPxCRP were calculated.

RESULTS

P1NP/ALPxALT and P1NP/ALPxCRP were significantly higher in subjects with MAFLD. FLI was a good, significant predictor of MAFLD occurrence, regardless of sex. In boys, P1NP/ALPxCRP was a comparable predictor as CRP (OR 1.14 vs. 1.17; p < 0.001). P1NP/ALPxCRP had better discrimination capability in boys (AUC = 0.79; p < 0.001). However, the use of this algorithm did not improve discriminatory power in comparison to CRP (AUC = 0.81; p < 0.001), but gave a better sensitivity for MAFLD prediction (86% vs. 59%).

CONCLUSIONS

We suggest that P1NP/ALPXCRP is a reliable tool for MAFLD prediction in routine pediatric practice.

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.

Variants in mitochondrial amidoxime reducing component 1 and hydroxysteroid 17-beta dehydrogenase 13 reduce severity of nonalcoholic fatty liver disease in children and suppress fibrotic pathways through distinct mechanisms

Genome-wide association studies in adults have identified variants in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) and mitochondrial amidoxime reducing component 1 (MTARC1) as protective against nonalcoholic fatty liver disease (NAFLD). We aimed to test their association with pediatric NAFLD liver histology and investigate their function using metabolomics. A total of 1450 children (729 with NAFLD, 399 with liver histology) were genotyped for rs72613567T>TA in HSD17B13, rs2642438G>A in MTARC1, and rs738409C>G in patatin-like phospholipase domain-containing protein 3 (PNPLA3). Genotype-histology associations were tested using ordinal regression. Untargeted hepatic proteomics and plasma lipidomics were performed in a subset of children. We found rs72613567T>TA in HSD17B13 to be associated with lower odds of NAFLD diagnosis (odds ratio, 0.7; 95% confidence interval, 0.6-0.9) and a lower grade of portal inflammation (p < 0.001). rs2642438G>A in MTARC1 was associated with a lower grade of hepatic steatosis (p = 0.02). Proteomics found reduced expression of HSD17B13 in carriers of the protective -TA allele. MTARC1 levels were unaffected by genotype. Both variants were associated with down-regulation of fibrogenic pathways. HSD17B13 perturbs plasma phosphatidylcholines and triglycerides. In silico modeling suggested p.Ala165Thr disrupts the stability and metal binding of MTARC1. Conclusion: Both HSD17B13 and MTARC1 variants are associated with less severe pediatric NAFLD. These results provide further evidence for shared genetic mechanisms between pediatric and adult NAFLD.

Nonalcoholic Fatty Liver Disease in Children with Obesity: Narrative Review and Research Gaps

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the leading hepatic disease in children, ranging from steatosis to steatohepatitis and fibrosis. Age, sex, hormonal levels, pubertal stages, genetic risk- and epigenetic factors are among the many influencing factors. Appearing predominantly in children with obesity, but not exclusively, it is the liver's manifestation of the metabolic syndrome but can also exist as an isolated entity.

SUMMARY

Pediatric NAFLD differs from the adult phenotype. This narrative review on NAFLD in children with obesity provides an overview of the current knowledge on risk factors, screening, and diagnostic methods, as well state-of-the-art treatment. The recent discussion on the proposition of a new nomenclature - Metabolic [Dysfunction-] Associated Liver Disease - is featured, and current gaps of knowledge are discussed.

KEY MESSAGES

Currently, there is no international consensus on screening and monitoring of pediatric NAFLD. With lifestyle interventions being the cornerstone of treatment, no registered pharmacological treatment for pediatric NAFLD is available. Development and validation of additional noninvasive biomarkers, scores and imaging tools suitable to subcategorize, screen and monitor pediatric patients are necessary. With a variety of upcoming and promising agents, clear recommendations for pediatric nonalcoholic steatohepatitis trials are urgently needed.

MAFLD: Renovation of clinical practice and disease awareness of fatty liver

Recently, international expert panels have proposed a new definition of fatty liver: metabolic dysfunction-associated fatty liver disease (MAFLD). MAFLD is not just a simple renaming of non-alcoholic fatty liver disease (NAFLD). The unique feature of MAFLD is the inclusion of metabolic dysfunctions, which are high-risk factors for events. In addition, MAFLD is independent of alcohol intake and the co-existing causes of liver disease. This new concept of MAFLD may have a widespread impact on patients, medical doctors, medical staff, and various stakeholders regarding fatty liver. Thus, MAFLD may renovate clinical practice and disease awareness of fatty liver. In this review, we introduce the definition of and rationale for MAFLD. We further describe representative cases showing how the diagnostic processes differ between MAFLD and NAFLD. We also summarize recent studies comparing MAFLD with NAFLD and discuss the impact of MAFLD on clinical trials, Japanese populations, and disease awareness.

Performance of Imaging Techniques in Non-invasive Diagnosis of Non-alcoholic Fatty Liver Disease in Children: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in children. With the continuous emergence of various non-invasive diagnostic methods, imaging techniques have always been considered as potential alternative methods to liver biopsy. This study aimed to evaluate the diagnostic performance of imaging techniques so as to search for the most promising technology.

METHODS

We searched English and Chinese databases. English databases included Cochran library, Embase, PubMed, and Web of Science, while Chinese databases included the Wanfang database and China National Knowledge Internet.

RESULTS

Finally, 11 articles were included (12 studies, one of which included studies on both fibrosis and steatosis). Further, 26.2% of the participants had mild steatosis, 34.1% had moderate steatosis, and 34.9% had severe steatosis. Also, 64.0% had any fibrosis, 29.1% had significant fibrosis, 13.8% had advanced fibrosis, and 2.8% had cirrhosis. Irrespective of the grade of fibrosis, transient elastography (TE) had higher sensitivity (97-100%), whereas magnetic resonance elastography (MRE) had the lowest sensitivity (58-63%). The pooled sensitivity and specificity of imaging techniques in diagnosing steatosis were 89% (95% CI, 71-96) and 89% (95% CI, 72-96), and AUROC 0.95 (95% CI, 93-97), multifrequency magnetic resonance elastography-hepatic fat fraction (mMRE-HFF) had the highest sensitivity (87%, 95% CI 77-97), ultrasonography (US) had the lowest specificity (96%, 95% CI 92-98%).

CONCLUSION

Imaging techniques have a good diagnostic performance for children with NAFLD, especially the diagnosis of liver fibrosis based on ultrasound or magnetic resonance elastography. Compared with different imaging techniques, TE has the best performance in diagnosing significant fibrosis. Liver stiffness measurement (LSM) is expected to become a biological indicator for routine screening, dynamic monitoring of disease changes, and prognostic evaluation.

Zonation in NASH - A key paradigm for understanding pathophysiology and clinical outcomes

Non-alcoholic fatty liver disease (NAFLD) exists as a spectrum ranging from simple steatosis to histologically defined hepatocyte injury and inflammatory changes that define steatohepatitis (NASH), and increase risk for fibrosis. Although zonal differences in NASH have not been systematically studied, periportal involvement has been associated with worse metabolic outcomes and more hepatic fibrosis as compared to pericentral disease. These data suggest that hepatic zonation of disease may influence the diversity of clinical presentations. Similarly, several randomized clinical trials suggest a differential response based on zonation of disease, with preferential effects on periportal (cysteamine) or pericentral disease (obeticholic acid, pioglitazone). Intriguingly, morphogenic pathways known to affect zonal development and maintenance - WNT/β-Catenin, Hedgehog, HIPPO/Yap/TAZ and Notch - have been implicated in NASH pathogenesis, and nuclear hormone receptors downstream of potential NASH therapeutics show zonal preferences. In this review, we summarize these data and propose that patient-specific activation of these pathways may explain the variability in clinical presentation, and the zone-specific response observed in clinical trials.

Non-alcoholic fatty liver disease in children and young adults is associated with increased long-term mortality

BACKGROUND & AIMS

Longitudinal data are scarce regarding the natural history and long-term risk of mortality in children and young adults with biopsy-confirmed non-alcoholic fatty liver disease (NAFLD).

METHODS

This nationwide, matched cohort study included all Swedish children and young adults (≤25 years) with biopsy-confirmed NAFLD (1966-2017; n = 718). NAFLD was confirmed histologically from all liver biopsies submitted to Sweden's 28 pathology departments, and further categorized as simple steatosis or steatohepatitis (NASH). Patients with NAFLD were matched to ≤5 general population controls by age, sex, calendar year and county (n = 3,457). To account for shared genetic and early-life factors, we also matched patients with NAFLD to full-sibling comparators. Using Cox regression, we estimated multivariable-adjusted hazard ratios (aHRs) and 95% CIs.

RESULTS

Over a median of 15.8 years, 59 patients with NAFLD died (5.5/1,000 person-years [PY]) compared to 36 population controls (0.7/1,000 PY; difference = 4.8/1,000 PY; multivariable aHR 5.88; 95% CI 3.77-9.17), corresponding to 1 additional death per 15 patients with NAFLD, followed for 20 years. The 20-year absolute risk of overall mortality was 7.7% among patients with NAFLD, and 1.1% among controls (difference = 6.6%; 95% CI 4.0-9.2). Findings persisted after excluding those who died within the first 6 months (aHR 4.65; 95% CI 2.92-7.42), and after using full-sibling comparators (aHR 11.72; 95% CI 3.18-43.23). Simple steatosis was associated with a 5.26-fold higher adjusted rate of mortality compared to controls (95% CI 3.05-9.07), and this was amplified with NASH (aHR 11.51, 95% CI 4.77-27.79). Most of the excess mortality was from cancer (1.67 vs. 0.07/1,000PY; aHR 15.60; 95% CI 4.97-48.93), liver disease (0.93 vs. 0.04/1,000PY; aHR 16.46; 95% CI 2.75-98.43) and cardiometabolic disease (1.12 vs. 0.14/1,000PY; aHR 4.32, 95% CI 1.73-10.79).

CONCLUSIONS

Swedish children and young adults with biopsy-confirmed NAFLD have significantly higher rates of overall, cancer-, liver- and cardiometabolic-specific mortality compared to matched general population controls.

LAY SUMMARY

Currently, the natural history and long-term risk of mortality in children and young adults with biopsy-confirmed non-alcoholic fatty liver disease (NAFLD) is unknown. This nationwide cohort study compared the risk of all-cause and cause-specific mortality in pediatric and young adult patients in Sweden with biopsy-confirmed NAFLD to matched general population controls. We found that compared to controls, children and young adults with biopsy-confirmed NAFLD and NASH have significantly higher rates of overall, cancer-, liver- and cardiometabolic-specific mortality.

Defining paediatric metabolic (dysfunction)-associated fatty liver disease: an international expert consensus statement

The term non-alcoholic fatty liver disease (NAFLD), and its definition, have limitations for both adults and children. The definition is most problematic for children, for whom alcohol consumption is usually not a concern. This problematic definition has prompted a consensus to rename and redefine adult NAFLD associated with metabolic dysregulation to metabolic (dysfunction)-associated fatty liver disease (MAFLD). Similarities, distinctions, and differences exist in the causes, natural history, and prognosis of fatty liver diseases in children compared with adults. In this Viewpoint we, an international panel, propose an overarching framework for paediatric fatty liver diseases and an age-appropriate MAFLD definition based on sex and age percentiles. The framework recognises the possibility of other coexisting systemic fatty liver diseases in children. The new MAFLD diagnostic criteria provide paediatricians with a conceptual scaffold for disease diagnosis, risk stratification, and improved clinical and multidisciplinary care, and they align with a definition that is valid across the lifespan.

In Utero Exposure to Mercury Is Associated With Increased Susceptibility to Liver Injury and Inflammation in Childhood

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of liver disease in children. Mercury (Hg), a ubiquitous toxic metal, has been proposed as an environmental factor contributing to toxicant-associated fatty liver disease.

APPROACH AND RESULTS

We investigated the effect of prenatal exposure to Hg on childhood liver injury by combining epidemiological results from a multicenter mother-child cohort with complementary in vitro experiments on monocyte cells that are known to play a key role in liver immune homeostasis and NAFLD. We used data from 872 mothers and their children (median age, 8.1 years; interquartile range [IQR], 6.5-8.7) from the European Human Early-Life Exposome cohort. We measured Hg concentration in maternal blood during pregnancy (median, 2.0 μg/L; IQR, 1.1-3.6). We also assessed serum levels of alanine aminotransferase (ALT), a common screening tool for pediatric NAFLD, and plasma concentrations of inflammation-related cytokines in children. We found that prenatal Hg exposure was associated with a phenotype in children that was characterized by elevated ALT (≥22.1 U/L for females and ≥25.8 U/L for males) and increased concentrations of circulating IL-1β, IL-6, IL-8, and TNF-α. Consistently, inflammatory monocytes exposed in vitro to a physiologically relevant dose of Hg demonstrated significant up-regulation of genes encoding these four cytokines and increased concentrations of IL-8 and TNF-α in the supernatants.

CONCLUSIONS

These findings suggest that developmental exposure to Hg can contribute to inflammation and increased NAFLD risk in early life.

Cholesterol-Induced M4-Like Macrophages Recruit Neutrophils and Induce NETosis

The liver is the central organ for cholesterol synthesis and homeostasis. The effects of dietary cholesterol on hepatic injury, mainly of oxidized low-density lipoproteins (OxLDL), are not fully understood. Here, we show that the degree of cholesterol oxidation had different impacts on the global gene expression of human M2-like macrophages, with highly oxidized LDL causing the most dramatic changes. M2-like macrophages and Kupffer cells undergo M4-like polarization, decreasing the expression of important markers, such as IL10, MRC1, and CD163. These cells also displayed functional changes, with reduced phagocytic capacity, increased neutrophil recruitment, and more effective neutrophil extracellular traps (NETs) induction. Our findings provide a link between LDL oxidation and modification of peripheral and liver macrophage function.

Performance Characteristics, Intra- and Inter-operator Agreement of Transient Elastography in Pediatric Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

Transient elastography (TE) is a valuable tool in assessment of hepatic steatosis and fibrosis using liver stiffness measurement (LSM) and controlled attenuation parameter (CAP), respectively. Although widely used in adults, little is known about performance characteristics and reproducibility of TE (using Fibroscan device) in evaluation of pediatric nonalcoholic fatty liver disease (NAFLD).

METHODS

We prospectively recruited children with NAFLD. Three consecutive Fibroscan examinations were performed during the same visit-twice by a single expert operator and once by a different novice operator. Intra and inter-operator agreement was calculated using concordance correlation coefficient (CCC). Failure was defined as inability to obtain 10 valid measurements and examination was considered unreliable if LSM interquartile range/median was greater 30%.

RESULTS

Fifty-one children (34 boys; median age 15 years) were recruited. Failure rates for expert and novice operator were 10% (5/51) and 12% (6/51) while unreliable readings were obtained in 2% (1/46) and 4% (2/45) of patients, respectively. Patients with failed/unreliable measurements were significantly more obese (median BMI 46.2 vs 33.1 kg/m2, P = 0.002) compared with those with reliable measurements. The intra-operator agreement was almost perfect for LSM and substantial for CAP values (CCC = 0.85 and 0.73, respectively). Inter-operator agreement was substantial for LSM and moderate for CAP values (CCC = 0.76 and 0.58, respectively). The inter-operator agreement in LSM did not vary significantly over time but showed an inverse correlation with BMI and CAP.

CONCLUSION

Our study demonstrated that use of TE in assessment of hepatic fibrosis and steatosis in children with NAFLD is highly reliable with low failure rate and highly reproducible with high intra- and inter-operator reproducibility.

AMPK/mTOR Signaling in Autophagy Regulation During Cisplatin-Induced Acute Kidney Injury

Autophagy is a conserved, multistep pathway that degrades and recycles dysfunctional organelles and macromolecules to maintain cellular homeostasis. Mammalian target of rapamycin (mTOR) and adenosine-monophosphate activated-protein kinase (AMPK) are major negative and positive regulators of autophagy, respectively. In cisplatin-induced acute kidney injury (AKI) or nephrotoxicity, autophagy is rapidly induced in renal tubular epithelial cells and acts as a cytoprotective mechanism for cell survival. Both mTOR and AMPK have been implicated in the regulation of autophagy in cisplatin-induced AKI. Targeting mTOR and/or AMPK may offer effective strategies for kidney protection during cisplatin-mediated chemotherapy.

Noninvasive diagnostic tools for pediatric NAFLD: where are we now?

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of liver disease in the pediatric population. It is a significant liver complication of obesity that also prominently affects children. Over the past decade, several noninvasive methods have been investigated for replacing liver biopsy to identify which children with NAFLD have nonalcoholic steatohepatitis (NASH) and fibrosis. These methods that aim to differentiate the type and extent of liver damage are based on two main different methodologies: a 'biological' approach centered on the quantification of circulating biomarkers; and a 'physical' approach established by analyzing different imaging data.

AREAS COVERED

In this review, we illustrate the state of the art and recent discoveries on noninvasive methods for the diagnosis of NAFLD, NASH, and advanced fibrosis.

EXPERT OPINION

Currently, noninvasive tests cannot diagnose NASH or determine the degree of fibrosis. However, several lines of evidence have suggested that if these tests are used in a complementary way with other laboratory tests and imaging they have the potential to be used to monitor progression of disease and response to therapy in pediatric NAFLD. Future scientific research will focus on combining these methods with multiple potential predictors of genetic susceptibility.

Weight loss, insulin resistance, and study design confound results in a meta-analysis of animal models of fatty liver

The classical drug development pipeline necessitates studies using animal models of human disease to gauge future efficacy in humans, however there is a low conversion rate from success in animals to humans. Non-alcoholic fatty liver disease (NAFLD) is a complex chronic disease without any established therapies and a major field of animal research. We performed a meta-analysis with meta-regression of 603 interventional rodent studies (10,364 animals) in NAFLD to assess which variables influenced treatment response. Weight loss and alleviation of insulin resistance were consistently associated with improvement in NAFLD. Multiple drug classes that do not affect weight in humans caused weight loss in animals. Other study design variables, such as age of animals and dietary composition, influenced the magnitude of treatment effect. Publication bias may have increased effect estimates by 37-79%. These findings help to explain the challenge of reproducibility and translation within the field of metabolism.

Lack of Augmenter of Liver Regeneration Disrupts Cholesterol Homeostasis of Liver in Mice by Inhibiting the AMPK Pathway

It is well known that excessive cholesterol accumulation within hepatocytes deteriorates nonalcoholic fatty liver disease (NAFLD). Augmenter of liver regeneration (ALR) has been reported to alleviate NAFLD through anti-apoptosis; however, whether ALR could protect liver from cholesterol-induced NAFLD remains unclear. Mice with heterozygous deletion of Gfer (the gene for ALR, Gfer ^+/-) were generated, and liver steatosis was induced by either choline-deficient ethionine-supplemented, methionine choline-deficient diet for 4 weeks, or high-fat diet for 16 weeks. The results showed that Gfer ^+/- mice developed a more severe fatty liver phenotype than Gfer ^+/+ mice. The livers of Gfer ^+/- mice exhibited a higher concentration of cholesterol and low-density lipoprotein compared with the normal mice. Transcriptome-based analysis predicts low-density lipoprotein receptor (LDLR) primarily involved in the metabolic pathway. The experiments further indicate that cholesterol accumulation within hepatocytes is closely associated with enhancing the expression of LDLR and activation of sterol regulatory element binding protein 2 (SREBP2). Because adenosine monophosphate-activated protein kinase (AMPK) is a critical regulator of SREBP2 activation, we measured whether the activity of AMPK was regulated by ALR. We found that knockdown of ALR expression inhibited the phosphorylation of LKB1, an upstream activator of AMPK, followed by AMPK inactivation and SREBP2 maturation/nuclear translocation, leading to extensive cholesterol accumulation. Meanwhile, cellular oxidative stress increased as a result of ALR knockdown, indicating that ALR might also have a role in suppressing reactive oxygen species production. Conclusion: Our results confirm that ALR regulates cholesterol metabolism and alleviates hepatic steatosis probably through the LKB1-AMPK-SREBP2-LDLR pathway in vivo and in vitro, providing a putative mechanism for combating fatty liver disease.

Enhanced liver fibrosis test for the non-invasive diagnosis of fibrosis in patients with NAFLD: A systematic review and meta-analysis

BACKGROUND & AIMS

The enhanced liver fibrosis (ELF) test has been proposed for the non-invasive assessment of advanced fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). We performed a systematic review to estimate the accuracy of this test against biopsy.

METHODS

In this systematic review, we searched MEDLINE, Embase, Web of Science and the Cochrane Library for studies that included patients with NAFLD and that used both liver biopsy (as the reference standard) and the ELF test. Two authors independently screened the references, extracted the data and assessed the quality of included studies. Due to the variation in reported thresholds, we used a multiple thresholds random effects model for meta-analysis (diagmeta R-package).

RESULTS

The meta-analysis of 11 studies reporting advanced fibrosis and 5 studies reporting significant fibrosis showed that the ELF test had a sensitivity of >0.90 for excluding fibrosis at a threshold of 7.7. However, as a diagnostic test at high thresholds, the test only achieved specificity and positive predictive value >0.80 in very high prevalence settings (>50%). To achieve a specificity of 0.90 for advanced and significant fibrosis, thresholds of 10.18 (sensitivity: 0.57) and 9.86 (sensitivity: 0.55) were required, respectively.

CONCLUSION

The ELF test showed high sensitivity but limited specificity to exclude advanced and significant fibrosis at low cut-offs. The diagnostic performance of the test at higher thresholds was found to be more limited in low-prevalence settings. We conclude that clinicians should carefully consider the likely disease prevalence in their practice setting and adopt suitable test thresholds to achieve the desired performance.

LAY SUMMARY

The enhanced liver fibrosis test has been suggested as a non-invasive blood test to aid the diagnosis of severe liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Our study results showed that the test has a high negative predictive value, especially in populations with low disease prevalence (likely encountered in primary care); so, it can exclude advanced fibrosis in patients with NAFLD. However, when prevalence is low, the positive predictive value of the enhanced liver fibrosis test is low, suggesting that additional strategies may be needed to make a positive diagnosis in such settings.

High-Throughput, Machine Learning-Based Quantification of Steatosis, Inflammation, Ballooning, and Fibrosis in Biopsies From Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Liver biopsy is the reference standard for staging and grading nonalcoholic fatty liver disease (NAFLD), but histologic scoring systems are semiquantitative with marked interobserver and intraobserver variation. We used machine learning to develop fully automated software for quantification of steatosis, inflammation, ballooning, and fibrosis in biopsy specimens from patients with NAFLD and validated the technology in a separate group of patients.

METHODS

We collected data from 246 consecutive patients with biopsy-proven NAFLD and followed up in London from January 2010 through December 2016. Biopsy specimens from the first 100 patients were used to derive the algorithm and biopsy specimens from the following 146 were used to validate it. Biopsy specimens were scored independently by pathologists using the Nonalcoholic Steatohepatitis Clinical Research Network criteria and digitalized. Areas of steatosis, inflammation, ballooning, and fibrosis were annotated on biopsy specimens by 2 hepatobiliary histopathologists to facilitate machine learning. Images of biopsies from the derivation and validation sets then were analyzed by the algorithm to compute percentages of fat, inflammation, ballooning, and fibrosis, as well as the collagen proportionate area, and compared with findings from pathologists' manual annotations and conventional scoring systems.

RESULTS

In the derivation group, results from manual annotation and the software had an interclass correlation coefficient (ICC) of 0.97 for steatosis (95% CI, 0.95-0.99; P < .001); ICC of 0.96 for inflammation (95% CI, 0.9-0.98; P < .001); ICC of 0.94 for ballooning (95% CI, 0.87-0.98; P < .001); and ICC of 0.92 for fibrosis (95% CI, 0.88-0.96; P = .001). Percentages of fat, inflammation, ballooning, and the collagen proportionate area from the derivation group were confirmed in the validation cohort. The software identified histologic features of NAFLD with levels of interobserver and intraobserver agreement ranging from 0.95 to 0.99; this value was higher than that of semiquantitative scoring systems, which ranged from 0.58 to 0.88. In a subgroup of paired liver biopsy specimens, quantitative analysis was more sensitive in detecting differences compared with the nonalcoholic steatohepatitis Clinical Research Network scoring system.

CONCLUSIONS

We used machine learning to develop software to rapidly and objectively analyze liver biopsy specimens for histologic features of NAFLD. The results from the software correlate with those from histopathologists, with high levels of interobserver and intraobserver agreement. Findings were validated in a separate group of patients. This tool might be used for objective assessment of response to therapy for NAFLD in practice and clinical trials.

Nonalcoholic Fatty Liver Disease in Children: Unique Considerations and Challenges

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence in concert with the global epidemic of obesity and is being diagnosed at increasingly younger ages. The unique histologic features and early presentation of disease in pediatrics suggest that children and adults may differ with regard to etiopathogenesis, with children displaying a greater vulnerability to genetic and environmental factors. Of significant relevance to pediatrics, in utero and perinatal stressors may alter the lifelong health trajectory of a child, increasing the risk of NAFLD and other cardiometabolic diseases. The development and progression of disease in childhood is likely to carry increased risk of long-term morbidity. Novel biomarkers and therapeutic agents are needed to avoid the otherwise inevitable health and societal consequences of this rapidly expanding pediatric population.

CHD is Associated With Higher Grades of NAFLD Predicted by Liver Stiffness

BACKGROUND AND AIM

Accumulating clinical and epidemiologic evidence indicates that nonalcoholic fatty liver disease (NAFLD) is not only associated with liver-related morbidity and mortality, but also with a greater risk of coronary heart disease (CHD). However, there is currently no diagnostic parameter for NAFLD that has been determined to reliably indicate the presence of CHD as a co-morbidity. We evaluated the liver stiffness and visceral fat thickness of NAFLD patients ultrasonographically to explore the relationship between liver stiffness, visceral fat thickness, and CHD, aiming to find explore the relationship between the liver stiffness and CHD.

METHODS

We enrolled 120 consecutive patients who had been initially diagnosed with CHD on the basis of their symptoms. All patients underwent coronary angiography or computed tomography angiography, and were classified into a CHD group and a non-CHD group on the basis of the results. All patients underwent liver ultrasonography, shear-wave elastography, and visceral fat thickness measurement.

RESULTS

NAFLD and visceral fat thickness were significantly positively correlated with CHD and Gensini score (P<0.001). Multivariate regression showed that age, male, cholesterol, liver stiffness, and visceral fat thickness were determinants of CHD. Age, cholesterol, liver stiffness, and visceral fat thickness cut-off points for the prediction of CHD were above 50 years old [area under the curve (AUC): 0.678; sensitivity, 87%; specificity, 42.6%], >3.76 mmol/L (AUC: 0.687; sensitivity, 68.4%; specificity, 64.8%), >6.1 kPa (AUC: 0.798; sensitivity, 50%; specificity, 92.6%), and >7.41 cm (AUC: 0.694; sensitivity, 52.6%; specificity, 87%), respectively. Compared with the use of age, gender, and cholesterol (model 1), the addition of the liver stiffness cut-off to model 1 resulted in a stronger predictive value (P=0.005).

CONCLUSIONS

High-grade NAFLD is more present in symptomatic CHD. The higher degree of liver stiffness in patients with NAFLD, the higher risk of CHD in these NAFLD patients.

Correlation of Clinical and Histopathologic Parameters with Ultrasonographic Grades in Pediatric Non-Alcoholic Fatty Liver Disease

BACKGROUND

Liver biopsy is the gold standard for diagnosing non-alcoholic steatohepatitis (NASH), but liver biopsy in children is not available in many institutes and many parents are reluctant to agree with the procedure. We investigated the correlation of clinical and pathologic parameters with the severity of non-alcoholic fatty liver disease (NAFLD) in pediatric patients using ultrasonographic examination methods and measured the prevalence of fatty pancreas in pediatric NAFLD.

METHODS

Liver biopsy and abdominal ultrasound (US) examinations were performed in 58 children (42 boys, 16 girls; mean age, 12 years; age range, 4-19 years) between March 2006 and August 2017. Fatty liver and fatty pancreas were evaluated by two independent radiologists using US according to 4- and 3-point scales, respectively. We then analyzed the correlations of clinical, laboratory, and histopathologic parameters with the ultrasonographic grade of steatosis.

RESULTS

Forty-two children showed simple steatosis (NAFLD activity score [NAS] ≤ 5) while 16 showed NASH (NAS > 5). Higher body mass index (BMI) percentile, waist circumference, hematocrit, insulin resistance, and lower insulin sensitivity index were significantly positively correlated with the grade of fatty liver. NAFLD activity score, amount of steatosis, and fibrosis significantly worsened as the fatty liver grade increased. Higher BMI, lower insulin sensitivity index, and boy were significantly positively correlated with the fatty pancreas grade.

CONCLUSION

Altogether, ultrasonographic severity of fatty liver shows good correlation with that of clinical parameters and hepatic pathology.

Noninvasive inflammatory markers for assessing liver fibrosis stage in autoimmune hepatitis patients

OBJECTIVE

To examine the accuracy of noninvasive inflammatory markers in predicting liver fibrosis stage in patients with autoimmune hepatitis (AIH).

PATIENTS AND METHODS

We enrolled 55 patients with AIH and 60 healthy controls in this study, and divided them into three groups: F0 (control); F1-F3 (noncirrhotic fibrosis); and F4 (cirrhosis). The following markers were analyzed for all participants: lymphocyte-to-neutrophil ratio (LNR); lymphocyte-to-platelet ratio (LPR); lymphocyte-to-monocyte ratio (LMR); immunoglobulin-to-platelet ratio (IGPR); aminotransferase-to-platelet ratio index (APRI); aspartate aminotransferase-to-alanine aminotransferase ratio (AAR); and fibrosis-4 score (FIB-4). The predictive accuracy of these noninvasive markers was assessed using area under the receiver operating characteristic curve. Multivariate ordinal logistic regression models were used to analyze associations between the noninvasive markers and liver fibrosis stage.

RESULTS

AAR, LPR, LMR, IGPR, APRI, and FIB-4 were linked to liver fibrosis-stage (P < 0.05), with correlation indices of - 0.219, 0.258, - 0.149, 0.647, 0.841, and 0.704, respectively, but not LNR (P = 0.093). area under the receiver operating characteristic curves of LPR, IGPR, AAR, LMR, APRI, and FIB-4 for detecting cirrhosis (F4 vs. F0-F3) were 0.936 (95% confidence interval: 0.870-1.000, P < 0.001), 0.939 (0.875-1.000, P < 0.001), 0.528 (0.319-0.738, P = 0.768), 0.555 (0.409-0.700, P = 0.568), 0.798 (0.694-0.902, P = 0.002), and 0.881 (0.796-0.967, P < 0.001). Our multivariate ordinal regression analysis showed that LPR and IGPR were associated independently with liver fibrosis stage, with a coefficient of 0.385 (95% confidence interval: 0.103-0.667, P = 0.007) and 14.903 (2.091-27.786, P = 0.023), respectively.

CONCLUSION

LPR and IGPR were associated independently with liver fibrosis stage in treatment-naive AIH, and were superior to APRI and FIB-4 in detecting cirrhosis.

Quercetin improves nonalcoholic fatty liver by ameliorating inflammation, oxidative stress, and lipid metabolism in db/db mice

Multiphase pathological processes involve in Type 2 diabetes (T2DM)-induced nonalcoholic fatty liver disease (NAFLD). However, the therapies are quite limited. In the present study, the hepatoprotective effects and underlying mechanisms of quercetin in T2DM-induced NAFLD were investigated. T2DM-induced NAFLD and quercetin treatment models were established in vivo and in vitro. The results revealed that quercetin alleviated serum transaminase levels and markedly reduced T2DM-induced histological alterations of livers. Additionally, quercetin restored superoxide dismutase, catalase, and glutathione content in livers. Not only that, quercetin markedly attenuated T2DM-induced production of interleukin 1 beta, interleukin 6, and TNF-α. Accompanied by the restoration of the increased serum total bile acid (p = .0001) and the decreased liver total bile acid (p = .0005), quercetin could reduce lipid accumulation in the liver of db/db mice. Further mechanism studies showed that farnesoid X receptor 1/Takeda G-protein-coupled receptor 5 signaling pathways was involved in quercetin regulation of lipid metabolism in T2DM-induced NAFLD. In high D-glucose and free fatty acid cocultured HepG2 cells model, quercetin eliminated lipid droplets and restored the upregulated total cholesterol and triglyceride levels. Similar to the findings in mice, quercetin could also activate farnesoid X receptor 1/Takeda G-protein-coupled receptor 5 signaling pathway. These findings suggested that quercetin might be a potentially effective drug for the treatment of T2DM-induced NAFLD.

Evaluations of Lifestyle, Dietary, and Pharmacologic Treatments for Pediatric Nonalcoholic Fatty Liver Disease: A Systematic Review

BACKGROUND & AIMS

There are no approved treatments for pediatric nonalcoholic fatty liver disease (NAFLD) and there is a lack of consensus on the best outcome measure for randomized controlled trials. We performed a systematic review of treatments tested for pediatric NAFLD, the degree of heterogeneity in trial design, and endpoints analyzed in these studies.

METHODS

We searched publication databases and clinical trial registries through January 7, 2018 for randomized controlled trials (published and underway) of children (<18 years) with NAFLD. We assessed improvements in histologic features, radiologic and biochemical markers of reduced fibrosis, metabolic syndrome parameters, and adverse events. The quality of the trials was assessed using a modified version of the Cochrane risk of bias tool.

RESULTS

Our final analysis included 21 randomized controlled trials, comprising 1307 participants (mean age, 12.6 years; 63% male; mean duration of intervention, 8 months). Most studies evaluated weight loss with lifestyle intervention (n=8), oral polyunsaturated fatty acid treatment (PUFAs, n=6), or oral antioxidant treatment (n=7). Biomarkers of NAFLD decreased with weight loss, but most studies did not include histologic data. Trials of antioxidants were heterogeneous; some reported reduced histologic features of steatohepatitis with no effect on triglycerides or insulin resistance. PUFAs and probiotics reduced radiologic markers of steatosis, insulin resistance, and levels of triglycerides. Only 38% of the trials had biopsy-proven NAFLD as an inclusion criterion. There was heterogeneity in trial primary endpoints; 10 studies (48%) used levels of aminotransferases or ultrasonography findings as a primary endpoint and only 3 trials (14%) used histologic features as the primary endpoint. We identified 13 randomized controlled trials that are underway in children with NAFLD. None of the protocols include collection of liver biopsies; 9 trials (69%) will use magnetic resonance imaging quantification of steatosis as a primary outcome.

CONCLUSIONS

In a systematic review of published and active randomized controlled trials of children with NAFLD, we found a large amount of heterogeneity in study endpoints and inclusion criteria. Few trials included histologic analyses. Antioxidants appear to reduce some features of steatohepatitis. Effects of treatment with lifestyle modification, PUFAs, or probiotics have not been validated with histologic analysis. Trials that are underway quantify steatosis magnetic resonance imaging-outcomes are anticipated.

Pediatric NAFLD: an overview and recent developments in diagnostics and treatment

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adults in industrialized countries. Besides liver-related morbidity, NAFLD is also associated with an increased risk of cardiovascular disease, type 2 diabetes and mortality at adult age. However, despite the high prevalence and serious complications, diagnosing and staging of disease remains complicated due to a lack of accurate screening tools and non-invasive methods to detect fibrosis. Areas covered: Recent insights in epidemiology, pathogenesis, diagnostic evaluation and treatment options in pediatric NAFLD are being reviewed, with a particular focus on new developments in diagnostic tools. Expert opinion: Due to their long life span, children with NAFLD are particularly at risk of complications in their lifetime. Therefore, an effective screening strategy for children to identify those with NAFLD at risk of complications is urgently needed. This is further underscored by new pharmacological therapies that are expected to become available in the next 5 years. Momentarily no accurate non-invasive method for diagnosing pediatric NAFLD is available. New promising biomarkers and imaging tools could hopefully provide better screening tools and could contribute to the development of a successful management plan to identify children with NAFLD.

Genetic determinants of steatosis and fibrosis progression in paediatric non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adolescents today. In comparison with adult disease, paediatric NAFLD may show a periportal localization, which is associated with advanced fibrosis. This study aimed to assess the role of genetic risk variants for histological disease pattern and severity in childhood NAFLD.

METHODS

We studied 14 single nucleotide polymorphisms (SNP) in a cohort of 70 adolescents with biopsy-proven NAFLD. Genotype was compared to an adult control cohort (n = 200) and analysed in relation to histological disease severity and liver tissue proteomics.

RESULTS

Three of the 14 SNPs were significantly associated with paediatric NAFLD after FDR adjustment, rs738409 (PNPLA3, P = 2.80 × 10^-06 ), rs1044498 (ENPP1, P = 0.0091) and rs780094 (GCKR, P = 0.0281). The severity of steatosis was critically associated with rs738409 (OR=3.25; 95% CI: 1.72-6.52, FDR-adjusted P = 0.0070). The strongest variants associated with severity of fibrosis were rs1260326, rs780094 (both GCKR) and rs659366 (UCP2). PNPLA3 was associated with a portal pattern of steatosis, inflammation and fibrosis. Proteome profiling revealed decreasing levels of GCKR protein with increasing carriage of the rs1260326/rs780094 minor alleles and downregulation of the retinol pathway in rs738409 G/G carriers. Computational metabolic modelling highlighted functional relevance of PNPLA3, GCKR and UCP2 for NAFLD development.

CONCLUSIONS

This study provides evidence for the role of PNPLA3 as a determinant of portal NAFLD localization and severity of portal fibrosis in children and adolescents, the risk variant being associated with an impaired hepatic retinol metabolism.

The Liver in Children With Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) is recognized as an emerging health risk in obese children and adolescents. NAFLD represents a wide spectrum of liver conditions, ranging from asymptomatic steatosis to steatohepatitis. The growing prevalence of fatty liver disease in children is associated with an increased risk of metabolic and cardiovascular complications. NAFLD is considered the hepatic manifestation of Metabolic Syndrome (MetS) and several lines of evidence have reported that children with NAFLD present one or more features of MetS. The pathogenetic mechanisms explaining the interrelationships between fatty liver disease and MetS are not clearly understood. Altough central obesity and insulin resistance seem to represent the core of the pathophysiology in both diseases, genetic susceptibility and enviromental triggers are emerging as crucial components promoting the development of NAFLD and MetS in children. In the present review we have identified and summarizied studies discussing current pathogenetic data of the association between NAFLD and MetS in children.

Gathering momentum for the way ahead: fifth report of the Lancet Standing Commission on Liver Disease in the UK

This report presents further evidence on the escalating alcohol consumption in the UK and the burden of liver disease associated with this major risk factor, as well as the effects on hospital and primary care. We reiterate the need for fiscal regulation by the UK Government if overall alcohol consumption is to be reduced sufficiently to improve health outcomes. We also draw attention to the effects of drastic cuts in public services for alcohol treatment, the repeated failures of voluntary agreements with the drinks industry, and the influence of the industry through its lobbying activities. We continue to press for reintroduction of the alcohol duty escalator, which was highly effective during the 5 years it was in place, and the introduction of minimum unit pricing in England, targeted at the heaviest drinkers. Results from the introduction of minimum unit pricing in Scotland, with results from Wales to follow, are likely to seriously expose the weakness of England's position. The increasing prevalence of obesity-related liver disease, the rising number of people diagnosed with type 2 diabetes and its complications, and increasing number of cases of end-stage liver disease and primary liver cancers from non-alcoholic fatty liver disease make apparent the need for an obesity strategy for adults. We also discuss the important effects of obesity and alcohol on disease progression, and the increased risk of the ten most common cancers (including breast and colon cancers). A new in-depth analysis of the UK National Health Service (NHS) and total societal costs shows the extraordinarily large expenditures that could be saved or redeployed elsewhere in the NHS. Excellent results have been reported for new antiviral drugs for hepatitis C virus infection, making elimination of chronic infection a real possibility ahead of the WHO 2030 target. However, the extent of unidentified cases remains a problem, and will also apply when new curative drugs for hepatitis B virus become available. We also describe efforts to improve standards of hospital care for liver disease with better understanding of current service deficiencies and a new accreditation process for hospitals providing liver services. New commissioning arrangements for primary and community care represent progress, in terms of effective screening of high-risk subjects and the early detection of liver disease.

Relationship between non-alcoholic steatohepatitis, PNPLA3 I148M genotype and bone mineral density in adolescents

BACKGROUND & AIMS

It is uncertain whether non-alcoholic steatohepatitis (NASH) is a risk factor for low bone mineral density (BMD). Our aim was to investigate: (a) associations between NASH and BMD values and (b) associations between PNPLA3 I148M genotypes and BMD, in children with histologically proven non-alcoholic fatty liver disease (NAFLD).

METHODS

BMD area (g/cm² ) was measured using dual-energy X-ray absorptiometry (DEXA). NASH was diagnosed by a Steatosis, Activity and Fibrosis (SAF) score and FLIP algorithm. Genotyping for patatin-like phospholipase domain containing-3 (PNPLA3) I148M genotype (rs738409) (CC, CG and GG) was undertaken using the TaqMan SNP genotyping allelic discrimination method. Logistic regression was used to test associations [OR (95% CIs)] between low BMD, and both NASH and PNPLA3 I148M genotypes.

RESULTS

Thirty-four adolescents (mean age 13.8 ± 1.1 years) with histologically confirmed NAFLD were studied. Subjects with NASH (n = 25) had a lower BMD (means (SDs) 0.87 ± 0.06 vs 0.97 ± 0.12, P = 0.005), compared to subjects without NASH. Subjects with PNPLA3 CG+GG genotypes had a lower BMD compared with subjects with PNPLA3-CC genotype (means (SDs) 0.79 ± 0.20 vs 0.92 ± 0.10, P = 0.009). PNPLA3 CG+GG genotypes were independently associated with NASH [OR (95% CIs 1.78, 1.24, 2.99)], and low BMD was associated with both PNPLA3 CG+GG (OR 3.62 (95% CIs 1.21, 5.53), P = 0.028) and with SAF score (OR 2.76 (95% CIs 1.12, 5.41), P = 0.045).

CONCLUSIONS

Taken together the independent associations between: (a) low BMD and PNPLA3 CG+GG genotype; (b) low BMD and NASH; and (c) PNPLA3 CG+GG genotype and NASH, provide support for a causal relationship between NASH and low BMD.

Liver Ultrasound Elastography: An Update to the World Federation for Ultrasound in Medicine and Biology Guidelines and Recommendations

The World Federation for Ultrasound in Medicine and Biology has produced these guidelines for the use of elastography techniques in liver diseases. For each available technique, the reproducibility, results and limitations are analyzed, and recommendations are given. This set of guidelines updates the first version, published in 2015. Since the prior guidelines, there have been several advances in technology. The recommendations are based on the international published literature, and the strength of each recommendation is judged according to the Oxford Centre for Evidence-Based Medicine. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases.

The gut microbiota in infants of obese mothers increases inflammation and susceptibility to NAFLD

Maternal obesity is associated with increased risk for offspring obesity and non-alcoholic fatty liver disease (NAFLD), but the causal drivers of this association are unclear. Early colonization of the infant gut by microbes plays a critical role in establishing immunity and metabolic function. Here, we compare germ-free mice colonized with stool microbes (MB) from 2-week-old infants born to obese (Inf-ObMB) or normal-weight (Inf-NWMB) mothers. Inf-ObMB-colonized mice demonstrate increased hepatic gene expression for endoplasmic reticulum stress and innate immunity together with histological signs of periportal inflammation, a histological pattern more commonly reported in pediatric cases of NAFLD. Inf-ObMB mice show increased intestinal permeability, reduced macrophage phagocytosis, and dampened cytokine production suggestive of impaired macrophage function. Furthermore, exposure to a Western-style diet in Inf-ObMB mice promotes excess weight gain and accelerates NAFLD. Overall, these results provide functional evidence supporting a causative role of maternal obesity-associated infant dysbiosis in childhood obesity and NAFLD.

Comparison of laboratory tests, ultrasound, or magnetic resonance elastography to detect fibrosis in patients with nonalcoholic fatty liver disease: A meta-analysis

Many noninvasive methods for diagnosing liver fibrosis (LF) have been proposed. To determine the best method for diagnosing LF in nonalcoholic fatty liver disease (NAFLD), we conducted a systemic review and meta-analysis to compare the performance of aspartate aminotransferase to platelets ratio index (APRI), fibrosis-4 index (FIB-4), BARD score, NAFLD fibrosis score (NFS), FibroScan, shear wave elastography (SWE), and magnetic resonance elastography (MRE) for diagnosing LF in NAFLD. We compared the sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUROC) of these noninvasive methods for detecting significant fibrosis (SF), advanced fibrosis (AF), and cirrhosis. Heterogeneity was explored using meta-regression. Sixty-four articles with a total of 13,046 NAFLD subjects were included. The overall mean prevalence of SF, AF, and cirrhosis was 45.0%, 24.0%, and 9.4% in NAFLD patients, respectively. With an APRI threshold of 1.0 and 1.5, the sensitivities and specificities were 50.0% and 84.0% and 18.3% and 96.1%, respectively, for AF. With a FIB-4 threshold of 2.67 and 3.25, the sensitivities and specificities were 26.6% and 96.5% and 31.8% and 96.0%, respectively, for AF. The summary sensitivities and specificities of BARD score (threshold of 2), NFS (threshold of -1.455), FibroScan M (threshold of 8.7-9), SWE, and MRE for detecting AF were 0.76 and 0.61, 0.72 and 0.70, 0.87 and 0.79, 0.90 and 0.93, and 0.84 and 0.90, respectively. The summary AUROC values using APRI, FIB-4, BARD score, NFS, FibroScan M probe, XL probe, SWE, and MRE for diagnosing AF were 0.77, 0.84, 0.76, 0.84, 0.88, 0.85, 0.95, and 0.96, respectively.

CONCLUSION

MRE and SWE may have the highest diagnostic accuracy for staging fibrosis in NAFLD patients. Among the four noninvasive simple indexes, NFS and FIB-4 probably offer the best diagnostic performance for detecting AF. (Hepatology 2017;66:1486-1501).

AMPK orchestrates an elaborate cascade protecting tissue from fibrosis and aging

Fibrosis is a common process characterized by excessive extracellular matrix (ECM) accumulation after inflammatory injury, which is also a crucial cause of aging. The process of fibrosis is involved in the pathogenesis of most diseases of the heart, liver, kidney, lung, and other organs/tissues. However, there are no effective therapies for this pathological alteration. Annually, fibrosis represents a huge financial burden for the USA and the world. 5'-AMP-activated protein kinase (AMPK) is a pivotal energy sensor that alleviates or delays the process of fibrogenesis. In this review, we first present basic background information on AMPK and fibrogenesis and describe the protective roles of AMPK in three fibrogenic phases. Second, we analyze the protective action of AMPK during fibrosis in myocardial, hepatic, renal, pulmonary, and other organs/tissues. Third, we present a comprehensive discussion of AMPK during fibrosis and draw a conclusion. This review highlights recent advances, vital for basic research and clinical drug design, in the regulation of AMPK during fibrosis.

Liver Adiposity and Metabolic Profile in Individuals with Chronic Spinal Cord Injury

PURPOSE

To quantify liver adiposity using magnetic resonance imaging (MRI) and to determine its association with metabolic profile in men with spinal cord injury (SCI).

MATERIALS AND METHODS

MRI analysis of liver adiposity by fat signal fraction (FSF) and visceral adipose tissue (VAT) was completed on twenty participants. Intravenous glucose tolerance test was conducted to measure glucose effectiveness (S_g) and insulin sensitivity (S_i). Lipid panel, fasting glucose, glycated hemoglobin (HbA1c), and inflammatory cytokines were also analyzed.

RESULTS

Average hepatic FSF was 3.7% ± 2.1. FSF was positively related to TG, non-HDL-C, fasting glucose, HbA1c, VAT, and tumor necrosis factor alpha (TNF-α). FSF was negatively related to S_i and testosterone. FSF was positively related to VAT (r = 0.48, p = 0.032) and TNF-α (r = 0.51, p = 0.016) independent of age, level of injury (LOI), and time since injury (TSI). The associations between FSF and metabolic profile were independent of VAT.

CONCLUSIONS

MRI noninvasively estimated hepatic adiposity in men with chronic SCI. FSF was associated with dysfunction in metabolic profile, central adiposity, and inflammation. Importantly, liver adiposity influenced metabolic profile independently of VAT. These findings highlight the significance of quantifying liver adiposity after SCI to attenuate the development of metabolic disorders.

AMPK: a novel target for treating hepatic fibrosis

Fibrosis is a common process of excessive extracellular matrix (ECM) accumulation following inflammatory injury. Fibrosis is involved in the pathogenesis of almost all liver diseases for which there is no effective treatment. 5'-AMP-activated protein kinase (AMPK) is a cellular energy sensor that can ameliorate the process of hepatic fibrogenesis. Given the existing evidence, we first introduce the basic background of AMPK and hepatic fibrosis and the actions of AMPK in hepatic fibrosis. Second, we discuss the three phases of hepatic fibrosis and potential drugs that target AMPK. Third, we analyze possible anti-fibrosis mechanisms and other benefits of AMPK on the liver. Finally, we summarize and briefly explain the current objections to targeting AMPK. This review may aid clinical and basic research on AMPK, which may be a novel drug candidate for hepatic fibrosis.

Oxidative Stress as a Critical Factor in Nonalcoholic Fatty Liver Disease Pathogenesis

SIGNIFICANCE

Nonalcoholic fatty liver disease (NAFLD), characterized by liver triacylglycerol build-up, has been growing in the global world in concert with the raised prevalence of cardiometabolic disorders, including obesity, diabetes, and hyperlipemia. Redox imbalance has been suggested to be highly relevant to NAFLD pathogenesis. Recent Advances: As a major health problem, NAFLD progresses to the more severe nonalcoholic steatohepatitis (NASH) condition and predisposes susceptible individuals to liver and cardiovascular disease. Although NAFLD represents the predominant cause of chronic liver disorders, the mechanisms of its development and progression remain incompletely understood, even if various scientific groups ascribed them to the occurrence of insulin resistance, dyslipidemia, inflammation, and apoptosis. Nevertheless, oxidative stress (OxS) more and more appears as the most important pathological event during NAFLD development and the hallmark between simple steatosis and NASH manifestation.

CRITICAL ISSUES

The purpose of this article is to summarize recent developments in the understanding of NAFLD, essentially focusing on OxS as a major pathogenetic mechanism. Various attempts to translate reactive oxygen species (ROS) scavenging by antioxidants into experimental and clinical studies have yielded mostly encouraging results.

FUTURE DIRECTIONS

Although augmented concentrations of ROS and faulty antioxidant defense have been associated to NAFLD and related complications, mechanisms of action and proofs of principle should be highlighted to support the causative role of OxS and to translate its concept into the clinic. Antioxid. Redox Signal. 26, 519-541.

Limitations and opportunities of non-invasive liver stiffness measurement in children

Changes in liver structure are an important issue in chronic hepatopathies. Until the end of the 20^th century, these changes could only be determined by histological analyses of a liver specimen obtained via biopsy. The well-known limitations of this technique (i.e., pain, bleeding and the need for sedation) have precluded its routine use in follow-up of patients with liver diseases. However, the introduction of non-invasive technologies, such as ultrasound and magnetic resonance imaging, for measurement of liver stiffness as an indirect marker of fibroses has changed this situation. Today, several non-invasive tools are available to physicians to estimate the degree of liver fibrosis by analysing liver stiffness. This review describes the currently available tools for liver stiffness determination that are applicable to follow-up of liver fibrosis/cirrhosis with established clinical use in children, and discusses their features in comparison to the “historical” tools.