Mitochondrial Alterations in Nonalcoholic Fatty Liver Disease. Pediatric Case Description of Three Submitted Sequential Biopsies

Nonalcoholic fatty liver disease (NAFLD) is a clinical-pathological syndrome that encompasses a wide spectrum of morphologic alterations, ranging from simple hepatic steatosis to a more severe stage, known as nonalcoholic steatohepatitis (NASH). The purpose of this clinical report was to contribute to the understanding of mitochondrial alterations in NAFLD. The child (13-month-old) underwent initial biopsy in the year 2000 and was diagnosed with diffuse macro and microvesicular steatosis. Two additional biopsies were performed in 2001 and 2004. A high percentage of microvesicular steatosis was observed in the biopsies performed in 2000 and 2001. Mitochondrial size was slightly increased in the biopsy performed in the year 2000, significantly increased in 2001 and decreased in 2004. The presence of "mitochondrial hypertrophy" in the hepatocytes of an asymptomatic pediatric patient whose disease presentation was typical of NAFLD, excluding other pathological processes, allowed us to suspect that such a defect was considered the primary mitochondrial disorder.

Cardiovascular risk factors and the metabolic syndrome in pediatric nonalcoholic fatty liver disease

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD), the most common cause of liver disease in children, is associated with obesity and insulin resistance. However, the relationship between NAFLD and cardiovascular risk factors in children is not fully understood. The objective of this study was to determine the association between NAFLD and the presence of metabolic syndrome in overweight and obese children. METHODS AND RESULTS: This case-control study of 150 overweight children with biopsy-proven NAFLD and 150 overweight children without NAFLD compared rates of metabolic syndrome using Adult Treatment Panel III criteria. Cases and controls were well matched in age, sex, and severity of obesity. Children with NAFLD had significantly higher fasting glucose, insulin, total cholesterol, low-density lipoprotein cholesterol, triglycerides, systolic blood pressure, and diastolic blood pressure than overweight and obese children without NAFLD. Subjects with NAFLD also had significantly lower high-density lipoprotein cholesterol than controls. After adjustment for age, sex, race, ethnicity, body mass index, and hyperinsulinemia, children with metabolic syndrome had 5.0 (95% confidence interval, 2.6 to 9.7) times the odds of having NAFLD as overweight and obese children without metabolic syndrome. CONCLUSIONS: NAFLD in overweight and obese children is strongly associated with multiple cardiovascular risk factors. The identification of NAFLD in a child should prompt global counseling to address nutrition, physical activity, and avoidance of smoking to prevent the development of cardiovascular disease and type 2 diabetes.

Midterm and long-term results of percutaneous endovascular treatment of venous outflow obstruction after pediatric liver transplantation

PURPOSE: To evaluate retrospectively the midterm and long-term results of percutaneous endovascular treatment of venous outflow obstruction after pediatric liver transplantation. MATERIALS AND METHODS: During a 9-year period, 18 children with obstruction of a hepatic vein (HV) or inferior vena cava (IVC) anastomosis underwent percutaneous transluminal angioplasty (PTA) with balloon dilation or stent placement in case of PTA failure after liver transplantation. Patients` body weights ranged from 7.7 kg to 42.6 kg (mean, 18.8 kg +/- 9). Potential predictors of patency were compared between balloon dilation and stent placement groups. RESULTS: Forty-two procedures were performed (range, 1-11 per patient; mean, 2). Technical and initial clinical success were achieved in all cases. Major complications included one case of pulmonary artery stent embolization and one case of hemothorax. Three children (25%) with HV obstruction were treated with PTA and nine (75%) were treated with stent placement. Three children with IVC obstruction (75%) were treated with PTA and one (25%) was treated with a stent. There were two children with simultaneous obstruction at the HV and IVC; one was treated with PTA and the other with a stent. Cases of isolated HV stenosis have a higher probability of patency with balloon-expandable stent treatment compared with balloon dilation (P < .05). Follow-up time ranged from 7 days to 9 years (mean, 42 months +/- 31), and the primary assisted patency rate was 100% when stent placement was performed among the first three procedures. CONCLUSIONS: In cases of venous outflow obstruction resulting from HV and/or IVC lesions after pediatric liver transplantation, percutaneous endovascular treatment with balloon dilation or stent placement is a safe and effective alternative treatment that results in long-term patency.

Multiple Clinical Presentations of Lymphoproliferative Disorders in Pediatric Liver Transplant Recipients: A Single-Center Experience

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication following solid organ transplantation that has been linked to Epstein-Barr virus (EBV) infection. The aim of this article was to describe a single-center experience with the multiplicity of clinical presentations of PTLD. Among 350 liver transplantations performed in 303 children, 13 survivor children displayed a histological diagnosis of PTLD (13/242 survivors; 5.4%). The age at diagnosis ranged from 12 to 258 months (median, 47), and the time from transplantation ranged from 1 to 84 months (median, 13). Ten of these children (76.9%) were EBV-naive prior to transplantation. Fever was present in all cases. The clinical signs at presentation were anemia (92.3%), diarrhea and vomiting (69.2%), recurrent upper airway infections (38.4%), Waldeyer ring lymphoid tissue hypertrophy (23.0%), abdominal mass lesions (30.7%), massive cervical and mediastinal adenopathy (15.3%), or gastrointestinal and respiratory symptoms (30.7%). One child developed fulminant hepatic allograft failure secondary to graft involvement by PTLD. Polymorphic PTLD was diagnosed in 6 patients; 7 had the diagnosis of lymphoma. Treatment consisted of stopping immunosuppression as well as starting intravenous gancyclovir and anti-CD20 monoclonal antibody therapy. The mortality rate was 53.8%. The clinical presentation of PTLD varied from fever of unknown origin to fulminant hepatic failure. The other symptoms that may be linked to the diagnosis of PTLD are pancytopenia, tonsil and adenoid hypertrophy, cervical or mediastinal lymph node enlargement, as well as abdominal masses. Despite numerous advances, the optimal treatment approach for PTLD is not completely known and the mortality rate is still high.

Sirolimus in Pediatric Liver Transplantation: A Single-Center Experience

Background and Aims. Liver transplantation (OLT) in children has seen significant improvements in recent years. Long-term immunosuppressive strategies have focused on avoiding the risks of long-term immunosuppression, particularly nephrotoxicity, de novo malignancy and late infections. Since its introduction in renal transplantation in 1999, sirolimus (SRL) has been used by an increasing number of liver transplant centers. The aim of this study was to review the experience using SRL in pediatric liver transplant recipients at a single center. Methods. Between 1989 and 2006, 318 children underwent OLT including 13 who were converted to SRL therapy because of tacrolimus-related side effects. The indications were posttransplant lymphoproliferative disease (PTLD; n = 11), nephrotoxicity (n = 1), and de novo autoimmune hepatitis (n = 1). One patient with PTLD previously concurrently displayed chronic rejection. SRL dosages ranged between 0.4 and 5 mg/d. The median duration of follow-up was 18 months. Results. PTLD recurred in 1 patient. There were no episodes of acute rejection. One child developed hyperlipidemia that resolved with diet and medication. Conclusions. Conversion from tacrolimus to SRL in selected pediatric liver transplant recipients is safe. Children with PTLD may benefit from immunosuppression with SRL after liver transplantation.

Intra-abdominal fat is related to metabolic syndrome and non-alcoholic fat liver disease in obese youth

Background: Previous studies have shown an association between adiposity, especially intra-abdominal adipose tissue, and hemodynamic/metabolic comorbidities in adults, however it is not clear in pediatric population. The aim of the study was to analyze the relationship between non-alcoholic fatty liver disease (NAFLD) and components of metabolic syndrome (MS) with values of intra-abdominal (IAAT) and subcutaneous (SCAT) adipose tissue in obese children and adolescents.Methods: Cross-sectional study. Subjects: 182 obese sedentary children and adolescents (aged 6 to 16 y), identified by the body mass index (BMI). Measurements: Body composition and trunk fat by dual-energy X-ray absorptiometry- DXA; lipid profile, blood pressure and pubertal stage were also assessed. NAFLD was classified as absent (0), mild (1), moderate (2) and severe (3), and intra-abdominal and subcutaneous abdominal fat thickness were identified by ultrasound. The MS was identified according to the cut offs proposed by World Health Organization adapted for children and adolescents. The chi-square test was used to compare categorical variables, and the binary logistic regression indicated the magnitude of the associations adjusted by potential cofounders (sex, age, maturation, NAFLD and HOMA-IR).Results: Higher quartile of SCAT was associated with elevated blood pressure (p = 0.015), but not associated with NAFLD (p = 0.665). Higher IAAT was positively associated with increased dyslipidemia (p = 0.001), MS (p = 0.013) and NAFLD (p = 0.005). Intermediate (p = 0.007) and highest (p = 0.001) quartile of IAAT were also associated with dyslipidemia, independently of age, sex, maturation, NAFLD and HOMA-IR (homeostatic model assessment-insulin resistance).Conclusion: Obese children and adolescents, with higher IAAT are more prone to develop MS and NAFLD than those with higher values of SCAT, independent of possible confounding variables. © 2013 Silveira et al.; licensee BioMed Central Ltd.

Nutritional risk and anthropometric evaluation in pediatric liver transplantation

OBJECTIVE: To analyze the nutritional status of pediatric patients after orthotopic liver transplantation and the relationship with short-term clinical outcome. METHOD: Anthropometric evaluations of 60 children and adolescents after orthotopic liver transplantation, during the first 24 hours in a tertiary pediatric intensive care unit. Nutritional status was determined from the Z score for the following indices: weight/age, height/age or length/age, weight/height or weight/length, body mass index/age, arm circumference/age and triceps skinfold/age. The severity of liver disease was evaluated using one of the two models which was adequated to the patients' age: 1. Pediatric End-stage Liver Disease, 2. Model for End-Stage Liver Disease. RESULTS: We found 50.0% undernutrition by height/age; 27.3% by weight/age; 11.1% by weight/height or weight/length; 10.0% by body mass index/age; 61.6% by arm circumference/age and 51.0% by triceps skinfold/age. There was no correlation between nutritional status and Pediatric End-stage Liver Disease or mortality. We found a negative correlation between arm circumference/age and length of hospitalization. CONCLUSION: Children with chronic liver diseases experience a significant degree of undernutrition, which makes nutritional support an important aspect of therapy. Despite the difficulties in assessment, anthropometric evaluation of the upper limbs is useful to evaluate nutritional status of children before or after liver transplantation.

Metabolic inflexibility and insulin resistance in obese adolescents with non-alcoholic fatty liver disease.

BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is a comorbidity of childhood obesity. OBJECTIVE We examined whole-body substrate metabolism and metabolic characteristics in obese adolescents with vs. without NAFLD. SUBJECTS Twelve obese (BMI ≥ 95th percentile) adolescents with and without NAFLD [intrahepatic triglyceride (IHTG) ≥5.0% vs. <5.0%] were pair-matched for race, gender, age and % body fat. METHODS Insulin sensitivity (IS) was assessed by a 3-h hyperinsulinemic-euglycemic clamp and whole-body substrate oxidation by indirect calorimetry during fasting and insulin-stimulated conditions. RESULTS Adolescents with NAFLD had increased (p < 0.05) abdominal fat, lipids, and liver enzymes compared with those without NAFLD. Fasting glucose concentration was not different between groups, but fasting insulin concentration was higher (p < 0.05) in the NAFLD group compared with those without. Fasting hepatic glucose production and hepatic IS did not differ (p > 0.1) between groups. Adolescents with NAFLD had higher (p < 0.05) fasting glucose oxidation and a tendency for lower fat oxidation. Adolescents with NAFLD had lower (p < 0.05) insulin-stimulated glucose disposal and lower peripheral IS compared with those without NAFLD. Although respiratory quotient (RQ) increased significantly from fasting to insulin-stimulated conditions in both groups (main effect, p < 0.001), the increase in RQ was lower in adolescents with NAFLD vs. those without (interaction, p = 0.037). CONCLUSION NAFLD in obese adolescents is associated with adverse cardiometabolic profile, peripheral insulin resistance and metabolic inflexibility.

Effect Of Roux-en-y Gastric Bypass On Nonalcoholic Fatty Liver Disease Evaluated Through Nafld Fibrosis Score: A Prospective Study.

Nonalcoholic fatty liver disease (NAFLD) is common among subjects who undergo bariatric surgery and its postsurgical improvement has been reported. This study aimed to determine the evolution of liver disease evaluated through NAFLD fibrosis score 12 months after surgery. It is a prospective cohort study which evaluated patients immediately before and 12 months following Roux-en-Y gastric bypass (RYGB). Mean score decreased from 1.142 to 0.066; surgery led to a resolution rate of advanced fibrosis of 55 %. Resolution was statistically associated with female gender, percentage of excess weight loss, postsurgical body mass index, postsurgical platelet count, and diabetes resolution. As previously reported by studies in which postsurgical biopsies were performed, RYGB leads to a great resolution rate of liver fibrosis. Since postsurgical biopsy is not widely available and has a significant risk, calculation of NAFLD fibrosis score is a simple tool to evaluate this evolution through a noninvasive approach.

Expression of the iron regulatory peptide hepcidin is reduced in patients with chronic liver disease

Disturbances in iron metabolism often accompany liver disease in humans and hepatic iron deposition is a frequent finding. Since the peptide hepcidin, a major regulator of body iron homeostasis, is synthesised in the liver, alterations in hepcidin expression could be responsible for these effects. To investigate this possibility, we studied hepcidin expression in liver biopsies from patients with hepatitis C virus (HCV) infection, non-alcoholic fatty liver disease (NAFLD) and hemochromatosis (HC). Total RNA was extracted from the liver tissue of 24 HCV, 17 NASH and 5 HC patients, and 17 liver transplant donors (controls). The levels of mRNA for hepcidin and several other molecules involved in iron metabolism (DMT1, Dcytb, hephaestin, ferroportin, TfR1, TfR2, HFE and HJV) were examined by ribonuclease protection assay and expressed relative to the housekeeping gene GAPDH. The expression of hepcidin was significantly decreased in HCV and NASH patients relative to control liver (109±16 and 200±44 versus 325±26 respectively; P=0.008 and 0.02). We have previously reported similar findings in patients with HC, and this was confirmed in the current analysis (176±21; P=0.003). In both HCV and NAFLD patients the expression of the iron reductase Dcytb and the transferrin binding regulatory molecule TfR2 was also decreased, while the cellular iron exporter ferroportin showed a significant increase. Levels of the mRNA for the iron oxidase hephaestin were lower in HCV patients alone, while expression of the major transferrin binding molecule TfR1 was decreased only in NAFLD patients. Of particular interest was the finding that the expression of HJV (which is mutated in patients with juvenile HC) was significantly increased in NAFLD patients. No changes were seen in the expression of the iron importer DMT1 or the regulatory molecule HFE. Decreased expression of hepcidin in patients with HCV and NAFLD provides an explanation why iron homeostasis could be perturbed in these disorders. Reduced hepcidin levels would increase intestinal iron absorption and iron release from macrophages, which could contribute to hepatic iron accumulation. This in turn could lead to alterations in the expression of various proteins involved in iron transport and its regulation. Indeed most of the changes in the expression of such molecules observed in this study are consistent with this. However, the mechanisms leading to changes in the expression of hepcidin in these diseases remain to be elucidated.

Liver transplantation and quality of life: relevance of a specific liver disease questionnaire

Aim: A positive effect of liver transplantation on health-related quality of life (HRQOL) has been well documented in previous studies using generic instruments. Our aim was to re-evaluate different aspects of HRQOL before and after liver transplantation with a relatively new questionnaire the `liver disease quality of life` (LDQOL). Methods: The LDQOL and the Short Form 36 (SF-36) questionnaires were applied to ambulatory patients, either in the transplant list (n=65) or after 6 months to 5 years of liver transplant (n=61). The aetiology of cirrhosis, comorbidities, model for end-stage liver disease (MELD) Child-Pugh scores and recurrence of liver disease after liver transplantation were analysed using the Mann-Whitney and Kruskall-Wallis tests. Results: In patients awaiting liver transplantation, MELD scores >= 15 and Child-Pugh class C showed statistically significant worse HRQOL, using both the SF-36 and the LDQOL questionnaires. HRQOL in pretransplant patients was found to be significantly worse in those with cirrhosis owing to hepatitis C (n=30) when compared with other aetiologies (n=35) in 2/7 domains of the SF-36 and in 7/12 domains of the LDQOL. Significant deterioration of HRQOL after recurrence of hepatitis C post-transplant was detected with the LDQOL questionnaire although not demonstrated with the SF-36. The statistically significant differences were in the LDQOL domains: symptoms of liver disease, concentration, memory and health distress. Conclusions: The LDQOL, a specific instrument for measuring HRQOL, has shown a greater accuracy in relation to liver symptoms and could demonstrate, with better reliability, impairments before and after liver transplantation.

Association of polymorphisms of glutamate-cystein ligase and microsomal triglyceride transfer protein genes in non-alcoholic fatty liver disease

Background and Aims: Although the metabolic risk factors for non-alcoholic fatty liver disease (NAFLD) progression have been recognized, the role of genetic susceptibility remains a field to be explored. The aim of this study was to examine the frequency of two polymorphisms in Brazilian patients with biopsy-proven simple steatosis or non-alcoholic steatohepatitis (NASH): -493 G/T in the MTP gene, which codes the protein responsible for transferring triglycerides to nascent apolipoprotein B, and -129 C/T in the GCLC gene, which codes the catalytic subunit of glutamate-cystein ligase in the formation of glutathione. Methods: One hundred and thirty-one biopsy-proven NAFLD patients (n = 45, simple steatosis; n = 86, NASH) and 141 unrelated healthy volunteers were evaluated. Genomic DNA was extracted from peripheral blood cells, and the -129 C/T polymorphism of the GCLC gene was determined by restriction fragment length polymorphism (RFLP). The -493 G/T polymorphism of the MTP gene was determined by direct sequencing of the polymerase chain reaction products. Results: The presence of at least one T allele in the -129 C/T polymorphism of the GCLC gene was independently associated with NASH (odds ratio 12.14, 95% confidence interval 2.01-73.35; P = 0.007), whereas, the presence of at least one G allele in the -493 G/T polymorphism of the MTP gene differed slightly between biopsy-proven NASH and simple steatosis. Conclusion: This difference clearly warrants further investigation in larger samples. These two polymorphisms could represent an additional factor for consideration in evaluating the risk of NAFLD progression. Further studies involving a larger population are necessary to confirm this notion.

Metabolic differences between male and female adolescents with non-alcoholic fatty liver disease, as detected by ultrasound

Background: Age, developmental stage and gender are risk factors for paediatric non-alcoholic fatty liver disease (NAFLD). Aims: The aim of this study was to identify differences in clinical or laboratory variables between sexes in adolescents with NAFLD. Methodology: Ninety obese adolescents including 36 males and 54 females were evaluated. Inclusion criteria for this study were a Body Mass Index above the 95th percentile, as set forth by the National Center for Health Statistics, and an age of 10-19 years. A clinical and laboratory evaluation was conducted for all adolescents. Results: The variables that were found to be predictive of NAFLD in adolescence were visceral fat, Aminotransferase, Gamma-Glutamyl Transferase, triglyderides, cholesterol and LDL-cholesterol. We also observed that cholesterol and LDL-cholesterol variables were influenced by gender, i.e. there was a significant statistical difference in the values of these variables between male and female adolescents. With regard to cholesterol serum concentrations, the risk was 6.99 times greater for females, compared with 1.2 times for males; and for LDL-cholesterol serum concentrations the risk was 8.15 times greater for females, compared with and 1.26 times for males. Conclusion: Female adolescents with NAFLD showed a significantly different metabolic behaviour than males.

Long-term results of the percutaneous transhepatic venoplasty of portal vein stenoses after pediatric liver transplantation

This paper has the objective to evaluate retrospectively the long-term results of transhepatic treatment of PV stenoses after pediatric LT. During an eight-yr period, 15 children with PV stenoses underwent PTA with balloon dilation or stent placement in case of PTA failure after LT. Patients` body weights ranged from 9.3 to 46 kg (mean, 15.5 kg). PV patency was evaluated in the balloon dilation and in the stent placement groups. Technical and clinical successes were achieved in all cases with no complication. Eleven patients (11/15; 73.3%) were successfully treated by single balloon dilation. Four patients (4/15; 26.7%) needed stent placement. One patient was submitted to stent placement during the same procedure because of PTA failure. The other three developed clinical signs of portal hypertension because of PV restenoses two, eight, and twenty-eight months after the first PTA. They had to be submitted to a new procedure with stent placement. The follow-up time ranged from 3 to 8.1 yr (mean, 6.3 yr). In conclusion, transhepatic treatment of PV stenoses after pediatric LT with balloon dilation or stent placement demonstrated to be a safe and effective treatment that results in long-term patency.