Metabolic Associated Fatty Liver Disease in Children and Adolescents: Mechanisms of a Silent Epidemic and Therapeutic Options.

Non-alcoholic fatty liver disease (NAFLD) is now identified as a hepatic sign of metabolic syndrome and is the most frequent cause of chronic liver disease in all ages. It is assumed that a genetic predisposition associated with epigenetic factors participates in the evolution of this condition. Visceral obesity and insulin resistance (IR) have always been considered the most important causative factors of Metabolic Syndrome (MetS) and NAFLD, but currently, the interaction between genetic heritage and environmental factors is increasingly considered fundamental in the genesis of metabolic disorders associated with NAFLD. In fact, in patients with NAFLD, insulin resistance, arterial hypertension, abdominal obesity, dyslipidemia and reduced intestinal permeability have often been found, as well as a higher prevalence of coronary artery disease, obstructive sleep apnea, polycystic ovary syndrome and osteopenia, which define a MetS framework. Early diagnosis is needed to prevent disease progression through primarily lifestyle interventions. Unfortunately, at present, there are no molecules recommended for pediatric patients. However, several new drugs are in clinical trials. For this reason, targeted studies on the interaction between genetics and environmental factors involved in the development of NAFLD and MetS and on the pathogenetic mechanisms that determine the evolution in non-alcoholic steatohepatitis (NASH), should be implemented. Therefore, it is desirable that future studies may be useful in identifying patients at risk of developing NAFLD and MetS early.

Combination Treatment with Hydroxytyrosol and Vitamin E Improves NAFLD-Related Fibrosis.

Non-alcoholic fatty liver disease (NAFLD)-related liver fibrosis results in the encapsulation of injured liver parenchyma by a collagenous scar mainly imputable to hepatic stellate cells' activation. Approved pharmacological treatments against NAFLD-related fibrosis are still lacking, but natural compounds such as hydroxytyrosol (HXT) and vitamin E (VitE), are emerging as promising therapeutic opportunities. In this study, the potential anti-fibrotic effect of HXT + VitE combination therapy was investigated in vitro and in vivo. In particular, tumor growth factor (TGF)-ß-activated LX-2 cells as an in vitro model, and carbon tetrachloride plus a Western diet as a mice model were employed. The effect of HXT + VitE on fibrosis was also investigated in children with biopsy-proven NAFLD. Our results demonstrated that HXT + VitE caused a reduction of proliferation, migration, contractility, and expression of pro-fibrogenic genes in TGF-ß-activated LX-2 cells. HXT + VitE treatment also antagonized TGF-ß-dependent upregulation of pro-oxidant NOX2 by interfering with nuclear translocation/activation of SMAD2/3 transcription factors. The mouse model of NAFLD-related fibrosis treated with HXT + VitE showed a marked reduction of fibrosis pattern by histology and gene expression. Accordingly, in children with NAFLD, HXT + VitE treatment caused a decrease of circulating levels of PIIINP and NOX2 that was supported over time. Our study suggests that HXT + VitE supplementation may improve NAFLD-related fibrosis.

Higher Levels of Plasma Hyaluronic Acid and N-terminal Propeptide of Type III Procollagen Are Associated With Lower Kidney Function in Children With Non-alcoholic Fatty Liver Disease.

Objective: Hyaluronic acid (HA) and N-terminal propeptide of type III procollagen (PIIINP) are two non-invasive biomarkers of liver fibrosis in non-alcoholic fatty liver disease (NAFLD). We examined the relationships of plasma levels of HA and PIIINP with kidney function in children with NAFLD. Methods: Plasma HA and PIIINP levels were measured using two commercially available enzyme-linked immunosorbent assay kits in a cohort of 106 Caucasian overweight or obese children with biopsy-proven NAFLD. Glomerular filtration rate (eGFR) was estimated using the Bedside Schwartz equation. Genotyping for the patatin-like phospholipase domain-containing protein-3 (PNPLA3) rs738409 variant was performed using an allelic discrimination assay. Results: Children with fibrosis F2 had significantly higher plasma PIIINP and HA levels than those with F0 or F1 fibrosis. Liver fibrosis was positively associated with plasma HA and PIIINP, as well as with the presence of the risk allele G of PNPLA3 rs738409 variant, and negatively with eGFR. Moreover, eGFR showed significant inverse associations with HA and PIIINP levels, as well as the presence of G of PNPLA3 rs738409, and liver fibrosis stage. Notably, our multivariable regression models showed that higher plasma PIIINP (standardized beta coefficient: -0.206, P = 0.011) and HA levels (standardized beta coefficient: -0.531, P < 0.0001) were associated with lower eGFR values, even after adjustment for age, sex, systolic blood pressure, PNPLA3 rs738409 genotype, and any stage of liver fibrosis. Conclusions: Higher levels of HA and PIIINP were associated with lower eGFR values in Caucasian children with biopsy-proven NAFLD, independently of PNPLA3 rs738409 genotype and other potential confounding factors.

Angiopoietin-2 levels correlates with disease activity in children with nonalcoholic fatty liver disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD), a chronic liver disease in children, ranges from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). We investigated the role of Angiopoietin-2 (Ang-2) as a biomarker for pediatric NAFLD-related liver damage. METHODS: We assessed the plasma levels of Ang-2 and cytokeratin-18 (CK18) fragments and their association with histologic activity in 76 children with NAFLD and 28 controls. RESULTS: The mean plasma levels of Ang-2 and CK18 were higher in children with NAFLD than in age-matched controls (Ang-2 155.4 ± 72.5 vs 7.5 ± 2.3 ng/mL, p < 0.001; CK18 390.4 ± 145.6 vs 193.9 ± 30.8 IU/L, p < 0.001). Ang-2 was significantly increased (p < 0.0001) in children with NASH (N = 41) while CK18 was significantly increased (p = 0.002) in children with fibrosis (N = 47). Ang-2 levels accurately predicted NASH (AUROC 0.911; 95% CI 0.844-0.979; p < 0.0001), while CK18 predicted both NASH (AUROC 0.827; 95% CI 0.735-0.919; p < 0.0001) and fibrosis (AUROC 0.724; 95% CI 0.611-0.837; p = 0.001). Ang-2 and CK18 in combination were good predictors of NASH with a sensitivity of 71.4% and a specificity of 100%. CONCLUSIONS: In conclusion, our data suggested Ang-2 as a suitable biomarker of NASH in the pediatric population. However, our findings need external validation in other cohorts. IMPACT: Several circulating factors have been extensively studied as potential biomarkers for NASH. Angiopoietin-2 circulating levels are increased in children with NAFLD and are associated with NASH. Angiopoietin-2 levels are more efficient than CK18 levels at assessing the most severe form of disease, and the combining of these two biomarkers reached a positive predictive value of 100% for NASH.

Antioxidant activity of Hydroxytyrosol and Vitamin E reduces systemic inflammation in children with paediatric NAFLD.

BACKGROUND: The rise in paediatric non-alcoholic fatty liver disease (NAFLD) is particularly alarming. We recently reported that Hydroxytyrosol (HXT) and Vitamin E (VitE) may improve oxidative stress, insulin resistance, and steatosis in children with biopsy-proven NAFLD. AIM: Here, we investigated if HXT+VitE may reduce systemic inflammation in the above-mentioned patients. METHODS: This study analysed the plasma levels of IL (interleukin)-6, IL-1ß, IL-10, tumour necrosis factor (TNF)-α, 4­hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2'deoxyguanosine (8-OHdG) in children enrolled in the HXT+VitE trial (ClinicalTrials.gov, NCT02842567). RESULTS: Changes in markers of systemic inflammation were found in both placebo (Pla) and HXT+VitE. In particular, after four months, the levels of IL-1ß and TNF-α were reduced in both groups, while IL-6 decreased, and IL-10 increased significantly only in the group treated with HXT+VitE. Children treated with HXT+VitE showed a significant decrease of 4-HNE and 8-OHdG that correlated with the improvement of triglyceride levels. Noticeably, only the 8-OHdG decrease correlated with steatosis amelioration and with the increase of IL-10 levels. CONCLUSION: The treatment with HXT and VitE reduced the NAFLD-related systemic inflammation in children, mainly by an increase of IL-10 circulating levels that occurred in response to DNA damage recovery, ultimately improving steatosis and hypertriglyceridemia.

ß-Klotho gene variation is associated with liver damage in children with NAFLD.

BACKGROUND & AIM: Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in adults and children. Along with obesity, diabetes and insulin resistance, genetic factors strongly impact on NAFLD development and progression. Dysregulated bile acid metabolism and the fibroblast growth factor 19 (FGF19) pathway play a pivotal role in NAFLD pathogenesis. However, the mechanism through which the FGF19 receptor system is associated with liver damage in NAFLD remains to be defined. METHODS: We evaluated the impact of the rs17618244 G>A ß-Klotho (KLB) variant on liver damage in 249 pediatric patients with biopsy-proven NAFLD and the association of this variant with the expression of hepatic and soluble KLB. In vitro models were established to investigate the role of the KLB mutant. RESULTS: The KLB rs17618244 variant was associated with an increased risk of ballooning and lobular inflammation. KLB plasma levels were lower in carriers of the rs17618244 minor A allele and were associated with lobular inflammation, ballooning and fibrosis. In HepG2 and Huh7 hepatoma cell lines, exposure to free fatty acids caused a severe reduction of intracellular and secreted KLB. Finally, KLB downregulation obtained by the expression of a KLB mutant in HepG2 and Huh7 cells induced intracellular lipid accumulation and upregulation of p62, ACOX1, ACSL1, IL-1ß and TNF-α gene expression. CONCLUSION: In conclusion, we showed an association between the rs17618244 KLB variant, which leads to reduced KLB expression, and the severity of NAFLD in pediatric patients. We can speculate that the KLB protein may exert a protective role against lipotoxicity and inflammation in hepatocytes. LAY SUMMARY: Genetic and environmental factors strongly impact on the pathogenesis and progression of non-alcoholic fatty liver disease (NAFLD). The FGF19/FGFR4/KLB pathway plays a pivotal role in the pathogenesis of NAFLD. The aim of the study was to investigate the impact of a genetic variant in the KLB gene on the severity of liver disease. Our data suggest that the KLB protein plays a protective role against lipotoxicity and inflammation in hepatocytes.

Plasma N-terminal propeptide of type III procollagen accurately predicts liver fibrosis severity in children with non-alcoholic fatty liver disease.

BACKGROUND & AIMS: We examined the diagnostic performance of plasma N-terminal propeptide of type III procollagen (PIIINP) levels, aspartate aminotransferase to platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score for predicting non-alcoholic steatohepatitis (NASH) and liver fibrosis stage in children/adolescents with non-alcoholic fatty liver disease (NAFLD). METHODS: We enrolled 204 children/adolescents with biopsy-proven NAFLD at the "Bambino Gesù" Children's Hospital. We measured plasma PIIINP levels using a commercially available enzyme-linked immunosorbent assay kit and calculated APRI and FIB-4 scores using standard methods. RESULTS: Children with NASH had higher plasma PIIINP levels, APRI and FIB-4 scores compared with those without NASH (all P < .001). However, PIIINP levels had much better diagnostic performance and accuracy than APRI and FIB-4 scores for predicting liver fibrosis stage. PIIINP levels correlated with the total NAFLD activity score (NAS) and its constituent components (P < .0001). The risk of either NASH or F ≥ 2 fibrosis progressively increased with increasing PIIINP levels (P < .0001), independent of age, gender, adiposity measures, insulin resistance, NAS score and the patatin-like phospholipase domain-containing protein-3 rs738409 polymorphism. For every 3.6 ng/mL increase in PIIINP levels, the likelihood of having F ≥ 2 fibrosis increased by ~14-fold (adjusted-odds ratio 14.1, 95% CI 5.50-35.8, P < .0001) after adjustment for the aforementioned risk factors. The area under the receiver operating characteristics curve was 0.921 (95% CI 0.87-0.97) for F ≥ 2 fibrosis, and 0.993 (95% CI 0.98-1.0) for F3 fibrosis respectively. CONCLUSIONS: Unlike APRI and FIB-4 scores, plasma PIIINP levels are a promising, non-invasive biomarker for diagnosing liver fibrosis stage in children/adolescents with biopsy-proven NAFLD.

Vitamin E for the treatment of E-antigen-positive chronic hepatitis B in paediatric patients: results of a randomized phase 2 controlled study.

BACKGROUND & AIMS: The treatment of chronic hepatitis B infection (CHB) in children is still an area of great uncertainty. Vitamin E is an immunostimulating/antioxidant compound proven to be safe and effective for the treatment of adult CHB. The aim of this phase 2 controlled study was to evaluate the safety and efficacy of vitamin E for the treatment of paediatric HBeAg-positive CHB. METHODS: Forty-six children were randomized in a 1:1 ratio to receive vitamin E at a dose of 15 mg/kg/day (in galenic preparation) or no treatment for 12 months and were monitored for the subsequent 12 months. Clinical, biochemical, haematological and serovirological evaluations were carried out every 3 months. RESULTS: No significant side effects were associated with the vitamin E treatment. At the end of the study, anti-HBe seroconversion was obtained in 7 of 23 (30.4%) of vitamin E-treated versus 1 of 23 (4.3%) of the control patients (P = 0.05), while a virological response (≥2 log decrease in HBV-DNA from baseline) was observed in 9 of 23 (39.1%) vs. 2 of 23 (8.7%) respectively (P = 0.035). CONCLUSIONS: Vitamin E administration for the treatment of paediatric CHB at the tested dosage has no significant side effects and may induce anti-HBe seroconversion. Vitamin E could represent a tool for the treatment of paediatric CHB.

Management of chronic hepatitis B in children: an unresolved issue.

Although a rather benign course of chronic hepatitis B virus (HBV) infection during childhood has been described, 3-5% and 0.01-0.03% of chronic carriers develop cirrhosis or hepatocellular carcinoma before adulthood. Considering the whole lifetime, the risk of hepatocellular carcinoma rises to 9-24% and the incidence of cirrhosis to 2-3% per year. The aim of this article is to review the current knowledge regarding the natural history and treatment of chronic hepatitis B in children and to focus on critical aspects and unresolved questions in the management of childhood HBV infection. A literature search was carried out on MEDLINE, EMBASE, and Web of Science for articles published in English in peer-reviewed journals from January 1980 to February 2013. The search terms used included "Hepatitis B virus infection," "children," "HBV," "interferon," "lamivudine," "adefovir," "entecavir," and "tenofovir." Articles resulting from these searches and relevant references cited in the articles retrieved were reviewed. The current goals of therapy are to suppress viral replication, reduce liver inflammation, and reverse liver fibrosis. Therapeutic options for children are currently limited, and the risk for viral resistance to current and future therapies is a particular concern. Based on the data available at this time, it is the consensus of the panel that it is not appropriate to treat children in the immune-tolerant phase or in the inactive carrier state. For children in the immune-active or reactivation phases, liver histology can help guide treatment decisions. Outside of clinical trials, interferon is the agent of choice in most cases; currently, available nucleoside analogs are secondary therapies.

Autoimmune hepatitis in children: an overview of the disease focusing on current therapies.

Autoimmune hepatitis (AIH) is an immune-mediated necroinflammatory disease of the liver characterized by elevation of IgG, presence of characteristic autoantibodies, and histological features of interface hepatitis. Two types of juvenile AIH have been recognized according to seropositivity for smooth muscle and/or antinuclear antibody (AIH type 1) or liver kidney microsomal antibody (AIH type 2). The exact pathogenesis of AIH is still unclear, but it is known that unidentified environmental factors, and occasionally drugs, might trigger disease in genetically susceptible individuals. The clinical spectrum of this disease is very wide, ranging from asymptomatic individuals with abnormal liver function to those with fulminant liver failure. The diagnosis is based on a combination of biochemical and histological parameters and on exclusion of other liver diseases. It is a relatively rare but devastating disease, which progresses rapidly unless immunosuppressive treatment is started promptly. Standard therapy consists of a combination of corticosteroids and azathioprine, which is efficacious in 80% of patients. Alternative therapies are increasingly being explored in patients who do not respond to standard treatment and/or have intolerable side-effects. The purpose of this paper is to review our current knowledge about AIH in children, evaluating mainly the therapeutic options for its treatment, considering also the newer immunosuppressant agents used in difficult-to-treat cases.

Hepatitis B virus infection in children.

Hepatitis B can develop in less than 5% of neonates of infected mothers, despite neonatal serovaccination. Most children will develop a chronic hepatitis. Most children are in an immune-tolerant or in an inactive phase. Interferon is the treatment of choice, in the rare cases where it is necessary.

Successful tenofovir treatment for fulminant hepatitis B infection in an infant.

Fulminant hepatic failure is defined by the presence of severe impairment of liver function, with or without encephalopathy, in patients with no underlying chronic liver disease. We report the case of a 4-month-old infant who developed fulminant hepatitis B infection and recovered concomitant with tenofovir therapy without liver transplantation.

Relationship between portal chronic inflammation and disease severity in paediatric non-alcoholic fatty liver disease.

BACKGROUND: The non-alcoholic steato-hepatitis Clinical Research Network has recently shown that portal chronic inflammation is associated with liver fibrosis in American children with non-alcoholic fatty liver disease. AIM: We tested whether the portal chronic inflammation-fibrosis association was present in a series of Italian children with non-alcoholic fatty liver disease. METHODS: We re-assessed the liver biopsies of 144 consecutive Italian children with non-alcoholic fatty liver disease aged 3-18 years and followed at the "Bambino Gesù" Paediatric Hospital. Non-alcoholic fatty liver disease and portal chronic inflammation were diagnosed using the non-alcoholic steato-hepatitis Clinical Research Network criteria. Anthropometry, body composition, liver enzymes, metabolic parameters and blood pressure were measured in all children. RESULTS: Two children had no portal chronic inflammation, 84 had mild and 58 more than mild portal chronic inflammation according to the non-alcoholic steato-hepatitis Clinical Research Network criteria. Children with no or mild portal chronic inflammation had the same clinical features of those with more than mild portal chronic inflammation except for insulin resistance, which was greater. There was no association between steatosis, lobular inflammation, ballooning, fibrosis and portal chronic inflammation. CONCLUSION: We were not able to confirm the existence of a clinico-pathological association between portal chronic inflammation and disease severity in a series of Italian children with non-alcoholic fatty liver disease. Some clinico-pathological correlates of paediatric non-alcoholic fatty liver disease may be population-specific.