Paediatric gastroenterology evaluation of overweight and obese children referred from primary care for suspected non-alcoholic fatty liver disease

Usefulness of Transient Elastography for Non-Invasive Diagnosis of Liver Fibrosis in Pediatric Non-Alcoholic Steatohepatitis

BACKGROUND

Transient elastography (FibroScan®) is a non-invasive and rapid method for assessing liver fibrosis. While the feasibility and usefulness of FibroScan® have been proven in adults, few studies have focused on pediatric populations. We aimed to determine the feasibility and usefulness of FibroScan® in Korean children.

METHODS

FibroScan® examinations were performed in 106 children (age, 5-15 years) who visited the Konyang University Hospital between June and September 2018. Liver steatosis was measured in terms of the controlled attenuation parameter (CAP), while hepatic fibrosis was evaluated in terms of the liver stiffness measurement (LSM). Children were stratified into obese and non-obese controls, according to body mass index (≥ or < 95th percentile, respectively).

RESULTS

The obese group was characterized by significantly higher levels of aspartate aminotransferase (AST, 57.00 ± 48.47 vs. 26.40 ± 11.80 IU/L; P < 0.001) and alanine aminotransferase (ALT, 91.27 ± 97.67 vs. 16.28 ± 9.78 IU/L; P < 0.001), frequency of hypertension and abdominal obesity (abdominal circumference > 95% percentile) (P < 0.001), CAP (244.4-340.98 dB/m), and LSM (3.85-7.77 kPa) (P < 0.001). On FibroScan®, 30 of 59 obese children had fibrosis (LSM > 5.5 kPa), whereas the remaining 29 did not (LSM < 5.5 kPa). Obese children with fibrosis had higher levels of AST (73.57 ± 56.00 vs. 39.86 ± 31.93 IU/L; P = 0.009), ALT (132.47 ± 113.88 vs. 48.66 ± 51.29 IU/L; P = 0.001), and gamma-glutamyl transferase (106.67 ± 69.31 vs. 28.80 ± 24.26 IU/L; P = 0.042) compared to obese children without fibrosis. LSM had high and significant correlation (P < 0.05) with AST, ALT, homeostasis model assessment for insulin resistance, and AST-to-platelet ratio index.

CONCLUSION

FibroScan® is clinically feasible and facilitates non-invasive, rapid, reproducible, and reliable detection of hepatic steatosis and liver fibrosis in the Korean pediatric population.

Non-Alcoholic Fatty Liver Disease in Children and Adolescents: Lifestyle Change - a Systematic Review and Meta-Analysis

INTRODUCTION AND AIM

This manuscript seeks to analyze the impact of lifestyle changes on body mass index (BMI), aminotransferases and steatosis in children and adolescents with nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

A review of PubMed, BIREME, Scopus, EMBASE, Medline and Web of Science databases 2015 was performed seeking studies addressing the impact of lifestyle interventions on children and/or adolescents with NAFLD. Inclusion were manuscripts written in Portuguese, English and Spanish, as well as age less than 18 years. Two reviewers performed the data extraction independently and differences were resolved by consensus. Outcome measures were BMI, serum aminotransferase levels and the presence of hepatic steatosis.

RESULTS

The literature search identified 71,012 articles. After excluding 46,397 duplicates and other clearly irrelevant studies, 89 publications were reviewed in detail. Another 55 studies were excluded at this stage. Subsequently, 18 were excluded due to lack of data and three new articles were found in the review of the references of previously identified manuscripts. Therefore, 19 studies that had evaluated 923 subjects (477 boys and 446 girls) aged 6-18 years were included in the review. In most studies, the intervention included aerobic exercise and diet. In nine studies, BMI improved significantly following the intervention. The vast majority of studies reported a benefit from the intervention on aminotransferase levels. Lifestyle changes also had a significant impact on steatosis, reducing the risk by 61%.

CONCLUSIONS

Lifestyle changes lead to significant improvements in BMI, aminotransferase levels and hepatic steatosis in children and adolescents with NAFLD.

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.

IL-17A, MCP-1, CCR-2, and ABCA1 polymorphisms in children with non-alcoholic fatty liver disease

OBJECTIVE

The prevalence of non-alcoholic fatty liver disease in children has risen significantly, owing to the worldwide childhood obesity epidemic in the last two decades. Non-alcoholic fatty liver disease is closely linked to sedentary lifestyle, increased body mass index, and visceral adiposity. In addition, individual genetic variations also have a role in the development and progression of non-alcoholic fatty liver disease. The aim of this study was to investigate the gene polymorphisms of MCP-1 (-2518 A/G) (rs1024611), CCR-2 (190 G/A) (rs1799864), ABCA1 (883 G/A) (rs4149313), and IL-17A (-197 G/A) (rs2275913) in obese Turkish children with non-alcoholic fatty liver disease.

METHODS

The study recruited 186 obese children aged 10-17 years, including 101 children with non-alcoholic fatty liver disease and 85 children without non-alcoholic fatty liver disease. Anthropometric measurements, insulin resistance, a liver panel, a lipid profile, liver ultrasound examination, and genotyping of the four variants were performed.

RESULTS

No difference was found between the groups in respect to age and gender, body mass index, waist/hip ratio, or body fat ratio. In addition to the elevated ALT levels, AST and GGT levels were found significantly higher in the non-alcoholic fatty liver disease group compared to the non non-alcoholic fatty liver disease group (p<0.05). The A-allele of IL-17A (-197 G/A) (rs2275913) was associated with non-alcoholic fatty liver disease (odds ratio [OR] 2.05, 95% confidence interval: 1.12-3.77, p=0.02).

CONCLUSIONS

The findings of this study suggest that there may be an association between IL-17A (-197 G/A) (rs2275913) polymorphism and non-alcoholic fatty liver disease development in obese Turkish children.

Prevalence of Nonalcoholic Fatty Liver Disease in Children with Obesity

OBJECTIVES

To determine the prevalence of nonalcoholic fatty liver disease (NAFLD) in children with obesity because current estimates range from 1.7% to 85%. A second objective was to evaluate the diagnostic accuracy of alanine aminotransferase (ALT) for NAFLD in children with obesity.

STUDY DESIGN

We evaluated children aged 9-17 years with obesity for the presence of NAFLD. Diseases other than NAFLD were excluded by history and laboratories. Hepatic steatosis was measured by liver magnetic resonance imaging proton density fat fraction. The diagnostic accuracy of ALT for detecting NAFLD was evaluated.

RESULTS

The study included 408 children with obesity that had a mean age of 13.2 years and mean body mass index percentile of 98.0. The study population had a mean ALT of 32 U/L and median hepatic magnetic resonance imaging proton density fat fraction of 3.7%. The estimated prevalence of NAFLD was 26.0% (95% CI 24.2%-27.7%), 29.4% in male patients (CI 26.1%-32.7%) and 22.6% in female patients (CI 16.0%-29.1%). Optimal ALT cut-point was 42 U/L (47.8% sensitivity, 93.2% specificity) for male and 30 U/L (52.1% sensitivity, 88.8% specificity) for female patients. The classification and regression tree model with sex, ALT, and insulin had 80% diagnostic accuracy for NAFLD.

CONCLUSIONS

NAFLD is common in children with obesity, but NAFLD and obesity are not concomitant. In children with obesity, NAFLD is present in nearly one-third of boys and one-fourth of girls.

Transgenerational impact of maternal obesogenic diet on offspring bile acid homeostasis and nonalcoholic fatty liver disease

Studies show maternal obesity is a risk factor for metabolic syndrome and nonalcoholic fatty liver disease (NAFLD) in offspring. Here we evaluated potential mechanisms underlying these phenotypes. Female C57Bl6 mice were fed chow or an obesogenic high-fat/high-sucrose (HF/HS) diet with subsequent mating of F1 and F2 female offspring to lean males to develop F2 and F3 generations, respectively. Offspring were fed chow or fibrogenic (high transfat, cholesterol, fructose) diets, and histopathological, metabolic changes, and bile acid (BA) homeostasis was evaluated. Chow-fed F1 offspring from maternal HF/HS lineages (HF/HS) developed periportal fibrosis and inflammation with aging, without differences in hepatic steatosis but increased BA pool size and shifts in BA composition. F1, but not F2 or F3, offspring from HF/HS showed increased steatosis on a fibrogenic diet, yet inflammation and fibrosis were paradoxically decreased in F1 offspring, a trend continued in F2 and F3 offspring. HF/HS feeding leads to increased periportal fibrosis and inflammation in chow-fed offspring without increased hepatic steatosis. By contrast, fibrogenic diet-fed F1 offspring from HF/HS dams exhibited worse hepatic steatosis but decreased inflammation and fibrosis. These findings highlight complex adaptations in NAFLD phenotypes with maternal diet.

Clinical Practice Approach to Nonalcoholic Fatty Liver Disease by Pediatric Gastroenterologists in the United States

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is common; however, no information is available on how pediatric gastroenterologists in the United States manage NAFLD. Therefore, study objectives were to understand how pediatric gastroenterologists in the US approach the management of NAFLD, and to identify barriers to care for children with NAFLD.

METHODS

We performed structured one-on-one interviews to ascertain each individual pediatric gastroenterologist's approach to the management of NAFLD in children. Responses were recorded from open-ended questions regarding screening for comorbidities, recommendations regarding nutrition, physical activity, medications, and perceived barriers to care.

RESULTS

Response rate was 72.0% (486/675). Mean number of patients examined per week was 3 (standard deviation [SD] 3.5). Dietary intervention was recommended by 98.4% of pediatric gastroenterologists. Notably, 18 different dietary recommendations were reported. A majority of physicians provided targets for exercise frequency (72.6%, mean 5.6 days/wk, SD 1.6) and duration (69.9%, mean 40.2 minutes/session, SD 16.4). Medications were prescribed by 50.6%. Almost one-half of physicians (47.5%) screened for type 2 diabetes, dyslipidemia, and hypertension. Providers who spent more than 25 minutes at the initial visit were more likely to screen for comorbidities (P = 0.003). Barriers to care were reported by 92.8% with 29.0% reporting ≥3 barriers.

CONCLUSIONS

The majority of US pediatric gastroenterologists regularly encounter children with NAFLD. Varied recommendations regarding diet and exercise highlight the need for prospective clinical trials. NAFLD requires a multidimensional approach with adequate resources in the home, community, and clinical setting.

Omega-3 for nonalcoholic fatty liver disease in children

Question An overweight 12-year-old male patient with nonalcoholic fatty liver disease has had little improvement in liver steatosis or triglyceride levels over the past 2 years. Is omega-3 supplementation useful in managing his condition?Answer Nonalcoholic fatty liver disease in children is prevalent in the Canadian population and can lead to liver fibrosis, cirrhosis, transplant, and reduced life expectancy. There is no recommended pharmacologic treatment of nonalcoholic fatty liver disease. Omega-3 fatty acids are associated with small improvements in liver steatosis and triglyceride concentrations. There are conflicting results with regard to liver function test results and insulin resistance, and while there might be histologic improvement revealed on biopsy, there is little evidence that fibrosis is improved. In children who have struggled to be consistent with the changes needed in their diet, particularly those with elevated triglyceride levels, there might be a role for omega-3 supplementation while continuing to focus on the mainstays of treatment (diet and physical activity); however, further research is still needed.

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.

Including Fibroblast Growth Factor-21 in Combined Biomarker Panels Improves Predictions of Liver Steatosis Severity in Children

Background: Previous studies reported conflicting results regarding the association between fibroblast growth factor-21 (FGF-21) and non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the feasibility of combining FGF-21, obesity indices, and biochemical tests for predicting high-grade liver steatosis in children. Methods: A total of 203 children and adolescents aged 5-18 years were enrolled, and their anthropometric data, body composition, liver ultrasound score for NAFLD (range, 0-6), biochemical test results, and FGF-21, leptin, and adiponectin levels were analyzed. Children were categorized according to body mass index (BMI) and NAFLD scores. Univariate analysis and multivariate linear regression were used to identify independent predictors for the degree of liver steatosis. The accuracy of the models was also evaluated using a receiver-operating characteristic (ROC) curve. Results: FGF-21 levels were significantly higher in subjects with high-grade liver steatosis (P < 0.001). In obese and overweight children, regression analysis indicated that higher BMI and higher gamma-glutamyl transferase (γ-GT), triglycerides (TG), and FGF-21 levels were independent risk factors strongly correlated with NAFLD scores. FGF-21 combined with any of the above parameters showed a larger area under the ROC (AUROC, 0.861-0.873) than either parameter used alone. Overall, the best performance was obtained by combing FGF-21, γ-GT, and TG, with an AUROC of 0.871, specificity of 82.54%, and sensitivity of 83.78% for predicting high-grade liver steatosis. Conclusion: BMI, FGF-21, γ-GT, and TG levels were strongly correlated with liver steatosis severity. Including FGF-21 in the biomarker panels may improve the accuracy for identifying obese and overweight children with high-grade liver steatosis.

Comparison of diagnostic accuracy of screening tests ALT and ultrasound for pediatric non-alcoholic fatty liver disease

Alanine aminotransferase (ALT) and ultrasound (US) are the most commonly used tools for detecting non-alcoholic fatty liver disease (NAFLD). No direct comparison of these two modalities in children exists. We aimed to compare head-to-head the diagnostic accuracy of ALT and US and their combination for detecting NAFLD in children with obesity. Ninety-nine children with severe obesity underwent simultaneous serum-ALT and abdominal ultrasound (US steatosis score 0-3). Proton magnetic resonance spectroscopy was used as reference standard for detecting steatosis/NAFLD. ROC curve analyses were performed to determine diagnostic performance and to determine optimum screening cut-points aiming for a specificity ≥ 80%. The area under the ROC (AUROC) of ALT and US were not significantly different (0.74 and 0.70, respectively). At the optimal ALT threshold (≥40 IU/L), sensitivity was 44% and specificity was 89%. At the optimal US steatosis score (≥ 2), sensitivity was 51% and specificity was 80%. Combining ALT and US did not result in better accuracy than ALT or US alone.Conclusion: ALT and US have comparable and only moderate diagnostic accuracy for detecting hepatic steatosis in children with obesity. A stepwise screening strategy combining both methods does not improve diagnostic accuracy. What is Known: • Alanine aminotransferase (ALT) and ultrasound (US) are the most commonly used tools for detecting non-alcoholic fatty liver disease (NAFLD). • ALT and ultrasound have mediocre accuracy in detecting steatosis in children with obesity. What is New: • In a head-to-head comparison, the difference in diagnostic accuracy of ALT and ultrasound in detecting steatosis is not significant. • A stepwise screening strategy combining both methods does not improve diagnostic accuracy.

Serum Immunoglobulin A Levels Do Not Correlate With Liver Disease Severity in Pediatric Nonalcoholic Fatty Liver Disease

Serum immunoglobulin A (IgA) is a biomarker of liver disease severity in adult nonalcoholic fatty liver disease (NAFLD). The objective of this study was to assess whether this is true in pediatric NAFLD. This was a retrospective study of children followed in the Steatohepatitis Center of a tertiary care center (2010-2017). Serum IgA levels, histology and biochemical markers of hepatocellular injury and metabolic dysregulation were collected. Of the 600 children with available serum IgA levels (mean age 14 ± 3 years, 62% boys, 80% non-Hispanic), IgA was elevated in 4%. The group with elevated IgA levels was younger and had a greater representation of Hispanic ethnicity compared with those with normal or low IgA. Body mass index and aminotransferases were not different between the groups. Histology was available for 170 children and was not different in those with elevated, normal and low IgA. In contrast to adults, serum IgA is not a biomarker of liver disease severity in pediatric NAFLD.

Nonalcoholic Liver Disease in Children and Adolescents

Pediatric nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in children. The spectrum of NAFLD ranges from steatosis to nonalcoholic steatohepatitis (NASH) to fibrosis. Obesity rates in children continue to rise and, as a result, NAFLD in children is becoming more prevalent. The pathophysiology, natural history, and progression of disease are still being elucidated but NAFLD/NASH in children may represent a more severe phenotype that will benefit from early identification and management.

Metabolic Features of Nonalcoholic Fatty Liver (NAFL) in Obese Adolescents: Findings From a Multiethnic Cohort

We conducted a prospective study in a large, multiethnic cohort of obese adolescents to characterize clinical and genetic features associated with pediatric nonalcoholic fatty liver (NAFL), the most common cause of chronic liver disease in youth. A total of 503 obese adolescents were enrolled, including 191 (38.0%) whites, 134 (26.6%) blacks, and 178 (35.4%) Hispanics. Participants underwent abdominal magnetic resonance imaging (MRI) to quantify hepatic fat fraction (HFF), an oral glucose tolerance test (OGTT) to assess glucose tolerance and insulin sensitivity, and the genotyping of three single-nucleotide polymorphisms (SNPs) associated with nonalcoholic fatty liver disease (NAFLD) (patatin-like phospholipase domain-containing protein 3 [PNPLA3] rs738409, glucokinase regulatory protein [GCKR] rs1260326, and transmembrane 6 superfamily member 2 [TM6SF2] rs58542926). Assessments were repeated in 133 subjects after a 2-year follow-up. Prevalence of nonalcoholic fatty liver (NAFL) was 41.6% (209 patients) and ranged widely among ethnicities, being 42.9% in whites, 15.7% in blacks, and 59.6% in Hispanics (P < 0.0001). Among adolescents with NAFL, blacks showed the highest prevalence of altered glucose homeostasis (66%; P = 0.0003). Risk factors for NAFL incidence were white or Hispanic ethnicity (P = 0.021), high fasting C-peptide levels (P = 0.0006), and weight gain (P = 0.0006), whereas baseline HFF (P = 0.004) and weight loss (P = 0.032) predicted resolution of NAFL at follow-up. Adding either gene variant to these variables improved significantly the model predictive performance.

CONCLUSION

Black obese adolescents are relatively protected from liver steatosis, but are more susceptible to the deleterious effects of NAFL on glucose metabolism. The combination of ethnicity/race with markers of insulin resistance and genetic factors might help identify obese youth at risk for developing NAFL.

Assessment of Nonalcoholic Fatty Liver Disease Progression in Children Using Magnetic Resonance Imaging

OBJECTIVE

To assess liver disease progression using paired magnetic resonance imaging (MRI) measurements of liver fat fraction (FF) and stiffness.

STUDY DESIGN

Retrospective cohort study including patients with nonalcoholic fatty liver disease who had undergone repeat MRI studies. Descriptive statistics were used, as well as Pearson or Spearman correlation when appropriate. Mixed model analyses were used to determine relationships between liver FF/stiffness and predictor variables.

RESULTS

Sixty-five patients (80% non-Hispanic, mean age 14 ± 3 years) were included. Time from first to last MRI was 27 ± 14 months. Over time, body mass index z score remained stable, and there were no significant differences in mean serum aminotransferases, insulin, glucose, triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) levels. However, the proportion of patients with alanine aminotransferase (ALT) < 50 U/L increased. MRI FF and stiffness decreased in 29% and 20% of patients, respectively, and increased in 25% and 22% of patients, respectively. There was a weak positive correlation between FF change and ALT change (r = 0.41, P = .053) and a moderate negative correlation between change in FF and change in serum HDL levels (r = -0.58, P = .004). After adjusting for HDL, increase in serum insulin was the only variable predictive of increase in FF (P = .061). There was no correlation between change in liver stiffness and change in ALT (r = .02, P = .910).

CONCLUSIONS

MRI-determined hepatic FF and stiffness improved in a minority of patients overtime. ALT levels were not reflective of the change in FF or stiffness. MRI-based imaging is complementary in the assessment of NAFLD progression.

Paediatric fatty liver disease (PeFLD): All is not NAFLD - Pathophysiological insights and approach to management

The recognition of a pattern of steatotic liver injury where histology mimicked alcoholic liver disease, but alcohol consumption was denied, led to the identification of non-alcoholic fatty liver disease (NAFLD). Non-alcoholic fatty liver disease has since become the most common chronic liver disease in adults owing to the global epidemic of obesity. However, in paediatrics, the term NAFLD seems incongruous: alcohol consumption is largely not a factor and inherited metabolic disorders can mimic or co-exist with a diagnosis of NAFLD. The term paediatric fatty liver disease may be more appropriate. In this article, we summarise the known causes of steatosis in children according to their typical, clinical presentation: i) acute liver failure; ii) neonatal or infantile jaundice; iii) hepatomegaly, splenomegaly or hepatosplenomegaly; iv) developmental delay/psychomotor retardation and perhaps most commonly; v) the asymptomatic child with incidental discovery of abnormal liver enzymes. We offer this model as a means to provide pathophysiological insights and an approach to management of the ever more complex subject of fatty liver.

Cross-sectional correlation between hepatic R2* and proton density fat fraction (PDFF) in children with hepatic steatosis

PURPOSE

To determine the relationship between hepatic proton density fat fraction (PDFF) and R2* in vivo.

MATERIALS AND METHODS

In this Health Insurance Portability and Accountability Act (HIPAA)-compliant, Institutional Review Board (IRB)-approved, cross-sectional study, we conducted a secondary analysis of 3T magnetic resonance imaging (MRI) exams performed as part of prospective research studies in children in whom conditions associated with iron overload were excluded clinically. Each exam included low-flip-angle, multiecho magnitude (-M) and complex (-C) based chemical-shift-encoded MRI techniques with spectral modeling of fat to generate hepatic PDFF and R2* parametric maps. For each technique and each patient, regions of interest were placed on the maps in each of the nine Couinaud segments, and composite whole-liver PDFF and R2* values were calculated. Pearson's correlation coefficients between PDFF and R2* were computed for each MRI technique. Correlations were compared using Steiger's test.

RESULTS

In all, 184 children (123 boys, 61 girls) were included in this analysis. PDFF estimated by MRI-M and MRI-C ranged from 1.1-35.4% (9.44 ± 8.76) and 2.1-38.1% (10.1 ± 8.7), respectively. R2* estimated by MRI-M and MRI-C ranged from 32.6-78.7 s-1 (48.4 ± 9.8) and 27.2-71.5 s-1 (42.2 ± 8.6), respectively. There were strong and significant correlations between hepatic PDFF and R2* values estimated by MRI-M (r = 0.874; P < 0.0001) and MRI-C (r = 0.853; P < 0.0001). The correlation coefficients (0.874 vs. 0.853) were not significantly different (P = 0.15).

CONCLUSION

Hepatic PDFF and R2* are strongly correlated with each other in vivo. This relationship was observed using two different MRI techniques.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:418-424.

Performance of fibrosis prediction scores in paediatric non-alcoholic fatty liver disease

AIM

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in children. The phenotype of NAFLD varies widely, and non-invasive predictors of disease severity are scarce and are needed to tailor clinical management.

METHODS

We compared liver fibrosis by histology with proposed non-invasive predictors of fibrosis, including alanine transaminase (ALT), aspartate transaminase (AST), AST/ALT ratio, AST to platelet ratio index, fibrosis-4, paediatric NAFLD fibrosis index and paediatric NAFLD fibrosis score.

RESULTS

The area under the curve of scores obtained while predicting fibrosis in children with NAFLD ranged from 0.51 to 0.67.

CONCLUSION

The tested non-invasive fibrosis scoring systems, some of which were originally designed for adult populations, did not adequately predict fibrosis in a paediatric cohort. Further development of risk prediction scores in children are needed for the management of paediatric patients and will likely need to be developed within a large paediatric data set in order to improve specificity and sensitivity.

Shear-wave ultrasound elastography of the liver in normal-weight and obese children

Background The identification and subsequent management of liver diseases in children is challenging due to the lack of non-invasive imaging biomarkers. Ultrasound shear-wave elastography (US-SWE) is an emerging imaging technique which can quantitatively assess liver stiffness and may be useful as a tool in the management of liver disease in overweight and obese children. Purpose To evaluate US-SWE velocities of the liver in normal-weight and obese children, to correlate US-SWE findings with age and body-mass-index (BMI), and to compare US-SWE values with qualitative assessment (i.e. normal versus abnormal echogenicity) of the liver by conventional US. Material and Methods A cohort of 300 children (mean age, 9.9 ± 5.3 years; age range, 0.06-18.9 years) were studied, comprising 176 normal-weight and 124 obese participants. In each patient, both US-SWE and conventional US of the liver were obtained. Three pediatric radiologists individually and in consensus determined whether liver parenchyma was of normal or abnormal echogenicity. Results US-SWE velocities differed between normal-weight and obese children (1.08 ± 0.14 versus 1.44 ± 0.39 m/s; P < 0.001), but not by gender. Multivariate linear regression demonstrated US-SWE velocity to be primarily associated with age in normal-weight children ( P < 0.05) and with BMI in obese children ( P < 0.001). In the obese group, mean US-SWE velocity was statistically higher in participants with abnormal echogenic livers than in those with normal-appearing livers (1.53 ± 0.38 vs. 1.17 ± 0.27). The difference was not significant in the normal-weight group. Conclusion US-SWE provides a useful quantitative imaging biomarker for evaluating liver stiffness in children.

Screening for non-alcoholic fatty liver disease in children: do guidelines provide enough guidance?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the industrialized world in children. Its high prevalence and important health risks make NAFLD highly suitable for screening. In practice, screening is widely, albeit not consistently, performed.

AIM

To review the recommendations on screening for NAFLD in children.

METHOD

Recommendations on screening were reviewed from major paediatric obesity guidelines and NAFLD guidelines. A literature overview is provided on open questions and controversies.

RESULTS

Screening for NAFLD is advocated in all obesity and most NAFLD guidelines. Guidelines are not uniform in whom to screen, and most guidelines do not specify how screening should be performed in practice. Screening for NAFLD remains controversial, due to lack of a highly accurate screening tool, limited knowledge to predict the natural course of NAFLD and limited data on its cost effectiveness.

CONCLUSIONS

Guidelines provide little guidance on how screening should be performed. Screening for NAFLD remains controversial because not all conditions for screening are fully met. Consensus is needed on the optimal use of currently available screening tools. Research should focus on new accurate screening tool, the natural history of NAFLD and the cost effectiveness of different screening strategies in children.

Serum Alanine Aminotransferase Trends and Their Relationship with Obesity and Metabolic Syndrome in United States Adolescents, 1999-2014

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD), characterized by hepatocyte dysfunction, fat accumulation, and fibrosis, is the most common cause of chronic liver disease in children. Elevated levels of serum alanine aminotransferase (ALT) are used clinically to identify potential liver dysfunction. Our goal was to assess for changes in the national prevalence of elevated ALT over time and potential relationship to trends in the metabolic syndrome (MetS) severity and elevated body mass index (BMI).

MATERIALS AND METHODS

We studied 5411 non-Hispanic white, non-Hispanic black, and Hispanic adolescents aged 12-19 with complete MetS Z-score and ALT data from the National Health and Nutrition Examination Survey 1999-2014. Elevated ALT levels were defined by two different cutoffs: one for both sexes (30 U/L) and another that was sex specific (22 U/L girls; 25 U/L boys). MetS severity was assessed using a sex- and race-/ethnicity-specific MetS Z-score.

RESULTS

We did not find a statistically significant linear increase in either mean ALT or the prevalence of elevated ALT differed over time. As expected, ALT levels were significantly correlated with BMI Z-score and MetS Z-score (P < 0.0001). Over time, BMI Z-scores increased and MetS severity Z-score decreased.

CONCLUSION

Prevalence of elevated ALT did not exhibit a linear change between 1999 and 2014 in U.S. adolescents, potentially due to divergent trends regarding BMI and MetS severity. Continued vigilance in monitoring BMI and ALT levels is advised for the U.S. adolescent population. MetS Z-score could act as an additional tool to monitor risk of elevated ALT and subsequent development of NAFLD.

Nonalcoholic fatty liver disease and the ongoing role of liver biopsy evaluation

Nonalcoholic fatty liver disease (NAFLD) is one of the most common underlying causes of chronically elevated liver tests and liver disease in adults and children worldwide and may be strongly suspected if not diagnosed by ever evolving and available serologic and imaging‐based noninvasive tests. However, the definitive diagnosis of the most progressive form of NAFLD, nonalcoholic steatohepatitis, and the identification of fibrosis stage still require liver biopsy evaluation as noninvasive testing has not replaced some of the specifics or the totality of information obtainable from liver biopsy. In this review, both the role and value of a liver biopsy evaluation in NAFLD/ nonalcoholic steatohepatitis are examined from publications related to a selected variety of settings. Details of the most commonly used semiquantitative methods of analysis are discussed, and some useful potential pitfalls for differential diagnostic consideration in liver biopsy interpretation are given. (Hepatology Communications 2017;1:370–378)

Increasing Burden of Chronic Liver Disease Among Adolescents and Young Adults in the USA: A Silent Epidemic

BACKGROUND AND AIMS

Chronic liver disease (CLD) starts or becomes established in the adolescent and young adult (AYA) age group. This study aimed to estimate trends in CLD prevalence among US AYAs and to assess factors associated with CLD.

METHODS

Cross-sectional data from 14,547 AYAs (population-weighted N = 68,274,386) aged 15-39 years enrolled in the National Health and Nutrition Examination Survey from 1988 to 2012 were used. Nonalcoholic fatty liver disease (NAFLD) was defined as elevated alanine aminotransferase (>19 U/L for females and >30 U/L for males) in subjects with BMI ≥ 25 kg/m²; alcoholic liver disease (ALD) as excessive alcohol use (≥3 drinks/day for men and ≥2 drinks/day for women) and elevated aminotransferases after excluding alternative etiologies. Participants were considered hepatitis C virus (HCV) positive if antibody to HCV and HCV-RNA was positive.

RESULTS

There was a sharp increase in the prevalence of CLD from 12.9% in 1988-1994 to 28.5% in 1999-2004 that remained stable after that (27.7%). NAFLD was the most common etiology accounting for 22% of all CLD in the later period. The prevalence of ALD has been steadily increasing throughout the years, while HCV has been decreasing. On multivariate analysis, being overweight/obese, Mexican-American ethnicity, later study period, older age, and male gender, were associated with higher odds of having CLD.

CONCLUSION

More than one quarter of US AYAs might be affected by CLD. CLD prevalence in this age group has more than doubled over the past three decades mainly due to rise in NAFLD prevalence.

Liver histology and diffusion-weighted MRI in children with nonalcoholic fatty liver disease: A MAGNET study

PURPOSE

To determine potential associations between histologic features of pediatric nonalcoholic fatty liver disease (NAFLD) and estimated quantitative magnetic resonance diffusion-weighted imaging (DWI) parameters.

MATERIALS AND METHODS

This prospective, cross-sectional study was performed as part of the Magnetic Resonance Assessment Guiding NAFLD Evaluation and Treatment (MAGNET) ancillary study to the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN). Sixty-four children underwent a 3T DWI scan (b-values: 0, 100, and 500 s/mm² ) within 180 days of a clinical liver biopsy of the right hepatic lobe. Three parameters were estimated in the right hepatic lobe: apparent diffusion coefficient (ADC), diffusivity (D), and perfusion fraction (F); the first assuming exponential decay and the latter two assuming biexponential intravoxel incoherent motion. Grading and staging of liver histology were done using the NASH CRN scoring system. Associations between histologic scores and DWI-estimated parameters were tested using multivariate linear regression.

RESULTS

Estimated means ± standard deviations were: ADC: 1.3 (0.94-1.8) × 10^-3 mm² /s; D: 0.82 (0.56-1.0) × 10^-3 mm² /s; and F: 17 (6.0-28)%. Multivariate analyses showed ADC and D decreased with steatosis and F decreased with fibrosis (P < 0.05). Associations between DWI-estimated parameters and other histologic features were not significant: ADC: fibrosis (P = 0.12), lobular inflammation (P = 0.20), portal inflammation (P = 0.27), hepatocellular inflammation (P = 0.29), NASH (P = 0.30); D: fibrosis (P = 0.34), lobular inflammation (P = 0.84), portal inflammation (P = 0.76), hepatocellular inflammation (P = 0.38), NASH (P = 0.81); F: steatosis (P = 0.57), lobular inflammation (P = 0.22), portal inflammation (P = 0.42), hepatocellular inflammation (P = 0.59), NASH (P = 0.07).

CONCLUSION

In children with NAFLD, steatosis and fibrosis have independent effects on DWI-estimated parameters ADC, D, and F. Further research is needed to determine the underlying mechanisms and clinical implications of these effects.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1149-1158.

NASPGHAN Clinical Practice Guideline for the Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease in Children: Recommendations from the Expert Committee on NAFLD (ECON) and the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN)

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease that occurs in the setting of insulin resistance and increased adiposity. It has rapidly evolved into the most common liver disease seen in the pediatric population and is a management challenge for general pediatric practitioners, subspecialists, and for health systems. In this guideline, the expert committee on NAFLD reviewed and summarized the available literature, formulating recommendations to guide screening and clinical care of children with NAFLD.

Function and Regulation of MicroRNAs and Their Potential as Biomarkers in Paediatric Liver Disease

MicroRNAs (miRNAs) are short non-coding RNAs involved in biological and pathological processes of every cell type, including liver cells. Transcribed from specific genes, miRNA precursors are processed in the cytoplasm into mature miRNAs and as part of the RNA-induced silencing complex (RISC) complex binds to messenger RNA (mRNA) by imperfect complementarity. This leads to the regulation of gene expression at a post-transcriptional level. The function of a number of different miRNAs in fibrogenesis associated with the progression of chronic liver disease has recently been elucidated. Furthermore, miRNAs have been shown to be both disease-and tissue-specific and are stable in the circulation, which has led to increasing investigation on their utility as biomarkers for the diagnosis of chronic liver diseases, including those in children. Here, we review the current knowledge on the biogenesis of microRNA, the mechanisms of translational repression and the use of miRNA as circulatory biomarkers in chronic paediatric liver diseases including cystic fibrosis associated liver disease, biliary atresia and viral hepatitis B.

Prevalence of Prediabetes and Type 2 Diabetes in Children With Nonalcoholic Fatty Liver Disease

IMPORTANCE

Nonalcoholic fatty liver disease (NAFLD) is a major chronic liver disease in children in the United States and is associated with insulin resistance. In adults, NAFLD is also associated with type 2 diabetes. To our knowledge, the prevalence of type 2 diabetes in children with NAFLD is unknown.

OBJECTIVE

To determine the prevalence of type 2 diabetes and prediabetes in children with NAFLD and assess type 2 diabetes and prediabetes as risk factors for nonalcoholic steatohepatitis (NASH).

DESIGN, SETTING, AND PARTICIPANTS

This was a multicenter, cross-sectional study at 12 pediatric clinical centers across the United States participating in the National Institute of Diabetes and Digestive and Kidney Diseases NASH Clinical Research Network. Children younger than 18 years with biopsy-confirmed NAFLD enrolled in the NASH Clinical Research Network.

MAIN OUTCOMES AND MEASURES

The presence of type 2 diabetes and prediabetes as determined by American Diabetes Association screening criteria using clinical history and fasting laboratory values.

RESULTS

There were 675 children with NAFLD included in the study with a mean age of 12.6 years and mean body mass index (calculated as weight in kilograms divided by height in meters squared) of 32.5. Most of the children were boys (480 of 675) and Hispanic (445 of 675).The estimated prevalence of prediabetes was 23.4% (95% CI, 20.2%-26.6%), and the estimated prevalence of type 2 diabetes was 6.5% (95% CI, 4.6%-8.4%). Girls with NAFLD had 1.6 (95% CI, 1.04-2.40) times greater odds of having prediabetes and 5.0 (95% CI, 2.49-9.98) times greater odds of having type 2 diabetes than boys with NAFLD. The prevalence of NASH was higher in those with type 2 diabetes (43.2%) compared with prediabetes (34.2%) or normal glucose (22%) (P < .001). The odds of having NASH were significantly higher in those with prediabetes (OR, 1.9; 95% CI, 1.21-2.9) or type 2 diabetes (OR, 3.1; 95% CI, 1.5-6.2) compared with those with normal glucose.

CONCLUSIONS AND RELEVANCE

In this study, nearly 30% of children with NAFLD also had type 2 diabetes or prediabetes. These children had greater odds of having NASH and thus were at greater long-term risk for adverse hepatic outcomes.

A Guide to Non-Alcoholic Fatty Liver Disease in Childhood and Adolescence

Non-Alcoholic Fatty Liver Disease (NAFLD) is now the most prevalent form of chronic liver disease, affecting 10%–20% of the general paediatric population. Within the next 10 years it is expected to become the leading cause of liver pathology, liver failure and indication for liver transplantation in childhood and adolescence in the Western world. While our understanding of the pathophysiological mechanisms underlying this disease remains limited, it is thought to be the hepatic manifestation of more widespread metabolic dysfunction and is strongly associated with a number of metabolic risk factors, including insulin resistance, dyslipidaemia, cardiovascular disease and, most significantly, obesity. Despite this, ”paediatric” NAFLD remains under-studied, under-recognised and, potentially, undermanaged. This article will explore and evaluate our current understanding of NAFLD in childhood and adolescence and how it differs from adult NAFLD, in terms of its epidemiology, pathophysiology, natural history, diagnosis and clinical management. Given the current absence of definitive radiological and histopathological diagnostic tests, maintenance of a high clinical suspicion by all members of the multidisciplinary team in primary and specialist care settings remains the most potent of diagnostic tools, enabling early diagnosis and appropriate therapeutic intervention.

Comparison of the Phenotype and Approach to Pediatric vs Adult Patients With Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the main chronic noncommunicable diseases in Westernized societies; its worldwide prevalence has doubled during the last 20 years. NAFLD has serious health implications not only for adults, but also for children. However, pediatric NAFLD is not only an important global problem in itself, but it is likely to be associated with increases in comorbidities, such as metabolic syndrome and cardiovascular diseases. There are several differences between NAFLD in children and adults, and it is not clear whether the disease observed in children is the initial phase of a process that progresses with age. The increasing prevalence of pediatric NAFLD has serious implications for the future adult population requiring appropriate action. Studies of NAFLD progression, pathogenesis, and management should evaluate disease phenotypes in children and follow these over the patient's lifetime. We review the similarities and differences of NAFLD between children and adults.

Lifestyle Interventions Including Nutrition, Exercise, and Supplements for Nonalcoholic Fatty Liver Disease in Children

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease among children. Lifestyle interventions, such as diet and exercise, are frequently recommended. Children with NAFLD have a distinct physiology that is different from obesity alone and has the potential to influence lifestyle treatments. Studies of diet alone in the treatment of pediatric NAFLD have focused on sugar and carbohydrate, but did not indicate any one dietary approach that was superior to another. For children who are obese and have NAFLD, weight loss may have a beneficial effect regardless of the diet used. Exercise is widely believed to improve NAFLD because a sedentary lifestyle, poor aerobic fitness, and low muscle mass are all risk factors for NAFLD. However, there have been no randomized controlled trials of exercise as a treatment for children with NAFLD. Studies of the combination of diet and exercise suggest a potential for improvement in serum alanine aminotransferase activity and/or magnetic resonance imaging liver fat fraction with intervention. There is also enthusiasm for the use of dietary supplements; however, studies in children have shown inconsistent effects of vitamin E, fish oil, and probiotics. This review presents the available data from studies of lifestyle intervention and dietary supplements published to date and highlights challenges that must be addressed in order to advance the evidence base for the treatment of pediatric NAFLD.

The Progression and Natural History of Pediatric Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the United States. Childhood NAFLD is associated with hepatic and nonhepatic morbidity and mortality. Nonhepatic associations include cardiovascular, metabolic, pulmonary, and psychological disorders. Cardiovascular conditions observed in childhood include left ventricular dysfunction. Furthermore, childhood obesity is associated with greater odds of having hepatocellular carcinoma as an adult. Evidence suggests that NAFLD may begin in utero in children of diabetic mothers. Thus rigorous efforts for structured diagnosis and follow-up are a priority to better develop the understanding of outcomes in pediatric NAFLD.

Relationships Between Alanine Aminotransferase, Serum Triglycerides, Body Mass Index and Nonalcoholic Fatty Liver Disease in an Outpatient Pediatric Clinic Population

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in children and adolescents. The goal of this study was to describe the demographic, anthropometric and biochemical data of children and adolescents diagnosed with NAFLD during a seven-year period in an outpatient pediatric clinic in the Southwest region of the US and to evaluate relationships between race, BMI, ALT, triglyceride levels, age and gender with a diagnosis of NAFLD. A retrospective medical record review of patients who attended an outpatient pediatric clinic with a billing diagnosis ICD-9 code of 571.8 was conducted. Forty-one patients met these criteria. The majority was male (74%) Hispanic (32%), Hispanic/Latino (68%) and obese. The small number of patients diagnosed with NAFLD in our study is consistent with previously reported results. Our results indicate that the population of this culturally diverse, high-risk population has significant clinical markers that are indicative of NAFLD.

Novel Molecular Mechanisms in the Development of Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in adults and children worldwide. NAFLD has become a severe health issue and it can progress towards a more severe form of the disease, the non-alcoholic steatohepatitis (NASH). A combination of environmental factors, host genetics, and gut microbiota leads to excessive accumulation of lipids in the liver (steatosis), which may result in lipotoxicity and trigger hepatocyte cell death, liver inflammation, fibrosis, and pathological angiogenesis. NASH can further progress towards liver cirrhosis and cancer. Over the last few years, cell-derived extracellular vesicles (EVs) have been identified as effective cell-to-cell messengers that transfer several bioactive molecules in target cells, modulating the pathogenesis and progression of NASH. In this review, we focused on recently highlighted aspects of molecular pathogenesis of NASH, mediated by EVs via their bioactive components. The studies included in this review summarize the state of art regarding the role of EVs during the progression of NASH and bring novel insight about the potential use of EVs for diagnosis and therapeutic strategies for patients with this disease.

Nonalcoholic Fatty Liver Disease and Fibrosis in Youth Taking Psychotropic Medications: Literature Review, Case Reports, and Management

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) has become a worldwide epidemic because of the greater prevalence of obesity. Despite implications for youth with severe mental disorders, little has been published in the psychiatric literature about this increasingly common medical comorbidity. The goals of this article are to: 1) provide an overview of the epidemiology and pathophysiology of NAFLD, including progression to nonalcoholic steatohepatitis (NASH); 2) describe two clinical cases illustrating difficulties faced in management; and 3) review screening recommendations, differential diagnosis, and monitoring and intervention approaches.

METHODS

A literature review was conducted, including guidelines and recommendations, with case presentations including case and control liver histology biopsy photographs.

RESULTS

NAFLD in childhood and adolescence, as a precursor to NASH, progresses to fibrosis in a small percentage of youth, leading to risk for early onset cirrhosis and the need for transplantation. The cases presented raise concern that youth with severe mental health disorders, already at greater risk for obesity and its sequelae, may be at higher risk for progression to NASH, potentially because of greater rates of weight gain on top of overweight or obese status, and to liver metabolism changes from psychotropic medications favoring fat deposition.

CONCLUSIONS

Patients with rapid weight gain into the overweight or obese categories, or who develop elevated liver transaminases that persist across 3-6 months, should be screened or referred for screening by their psychotropic-providing clinicians for early detection, diagnosis, and co-management by a pediatric gastroenterologist, to decrease risk of progression to NASH, which is reversible if early and sufficient lifestyle change results in significant weight loss. There is urgent need for controlled research on the relationships among weight gain, psychotropic medications, ultrasound and biopsy findings, and rates of progression to NAFLD and NASH in youth taking weight-gain-inducing psychotropic medications.

Improvement of BMI after Lifestyle Intervention Is Associated with Normalisation of Elevated ELF Score and Liver Stiffness in Obese Children

Background. Noninvasive tools to diagnose nonalcoholic fatty liver disease (NAFLD), including transient elastography (TE) and enhanced liver fibrosis panel (ELF), have only been evaluated in children with biopsy-proven NAFLD. We evaluated the prevalence of ELF and TE abnormalities in obese children without clinical liver disease and examined the effects of BMI stabilization on ELF and TE in a longitudinal approach. Methods. 39 obese children (17 m, age 12.3 (7.6–17.4) years) who participated in a 12-month lifestyle-intervention program underwent TE and ELF testing at baseline and at completion of the program. Results were compared with data from a nonobese paediatric cohort. Results. TE and ELF at baseline were significantly elevated compared to controls (TE: 5.9 (3.4–8.3) kPa versus 4.45 (2.45–8.85) kPa, P < 0.01; ELF: 9.0 (7.87–9.60) versus 8.6 (7.33–11.52), P = 0.033). All children with elevated TE and ELF results had normal transaminases. After the program, ELF and TE normalized. Reduction of ELF and TE was associated with a decrease in BMI centile. Conclusion. Abnormal TE and ELF results in obese children suggest presence of NAFLD even when transaminases are normal. TE and ELF might be used as monitoring tools for NAFLD. BMI stabilisation normalizes TE and ELF, underlining the impact of lifestyle intervention.

Paediatric non-alcoholic fatty liver disease: a practical overview for non-specialists

Non-alcoholic fatty liver disease (NAFLD) is the most common paediatric liver disease with a prevalence of almost 10%; therefore, the majority of affected patients are under the care of general practitioners and non-specialists. The condition is caused by central obesity with insulin resistance with additional factors influencing inflammatory activity (steatohepatitis). Ongoing inflammation leads to fibrosis and end-stage liver disease, though this will usually occur after children have transitioned into adult care. However, their main morbidity and mortality is from type 2 diabetes and complications of atherosclerosis. The minority of children undergo biopsy but currently there is no other method to accurately assess the stage of disease. Management is focused at weight loss through a combination of diet and exercise. Here, we present a current review of paediatric NAFLD aimed at non-specialists, with practice points for implementation.

The full spectrum of hepatic steatosis in children

OBJECTIVE

We aim to identify the spectrum of etiologies of steatosis in pediatric liver biopsies.

METHODS

Information was collected from 155 children with steatosis on liver biopsy, including anthropometrics, laboratory, and radiologic data. Biopsies were reviewed by a liver pathologist.

RESULTS

The 4 major diagnoses associated with hepatic steatosis were nonalcoholic fatty liver disease (37%), metabolic disease (9%), oncologic disease (8%) and viral hepatitis (7%). Patients with nonalcoholic fatty liver disease were older (P = .0001) and more likely to have a body mass index z score >2 (P < .0001). Patients with a metabolic diagnosis were younger (P = .0002). Radiologic imaging of the liver yielded normal results in 44 of 108 of children (30%); 7 of these had >66% macrovesicular fatty change on biopsy, and 3 had severe fibrosis/cirrhosis.

CONCLUSIONS

The range of causes of steatosis in pediatric liver biopsies is broad. Not all patients, even with advanced liver disease, had abnormalities with liver imaging, emphasizing the role for liver biopsy in certain cases.

Magnetic resonance imaging and liver histology as biomarkers of hepatic steatosis in children with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children. In order to advance the field of NAFLD, noninvasive imaging methods for measuring liver fat are needed. Advanced magnetic resonance imaging (MRI) has shown great promise for the quantitative assessment of hepatic steatosis but has not been validated in children. Therefore, this study was designed to evaluate the correlation and diagnostic accuracy of MRI-estimated liver proton density fat fraction (PDFF), a biomarker for hepatic steatosis, compared to histologic steatosis grade in children. The study included 174 children with a mean age of 14.0 years. Liver PDFF estimated by MRI was significantly (P < 0.01) correlated (0.725) with steatosis grade. The correlation of MRI-estimated liver PDFF and steatosis grade was influenced by both sex and fibrosis stage. The correlation was significantly (P < 0.01) stronger in girls (0.86) than in boys (0.70). The correlation was significantly (P < 0.01) weaker in children with stage 2-4 fibrosis (0.61) than children with no fibrosis (0.76) or stage 1 fibrosis (0.78). The diagnostic accuracy of commonly used threshold values to distinguish between no steatosis and mild steatosis ranged from 0.69 to 0.82. The overall accuracy of predicting the histologic steatosis grade from MRI-estimated liver PDFF was 56%. No single threshold had sufficient sensitivity and specificity to be considered diagnostic for an individual child.

CONCLUSIONS

Advanced magnitude-based MRI can be used to estimate liver PDFF in children, and those PDFF values correlate well with steatosis grade by liver histology. Thus, magnitude-based MRI has the potential for clinical utility in the evaluation of NAFLD, but at this time no single threshold value has sufficient accuracy to be considered diagnostic for an individual child.

Developmental Programming of Nonalcoholic Fatty Liver Disease: The Effect of Early Life Nutrition on Susceptibility and Disease Severity in Later Life

Nonalcoholic fatty liver disease (NAFLD) is fast becoming the most common liver disease globally and parallels rising obesity rates. The developmental origins of health and disease hypothesis have linked alterations in the early life environment to an increased risk of metabolic disorders in later life. Altered early life nutrition, in addition to increasing risk for the development of obesity, type 2 diabetes, and cardiovascular disease in offspring, is now associated with an increased risk for the development of NAFLD. This review summarizes emerging research on the developmental programming of NAFLD by both maternal obesity and undernutrition with a particular focus on the possible mechanisms underlying the development of hepatic dysfunction and potential strategies for intervention.