Review article: the management of paediatric nonalcoholic fatty liver disease.

BACKGROUND: Paediatric nonalcoholic fatty liver disease (NAFLD) is a major public health concern given the recent increase in its prevalence and link to obesity and other metabolic comorbidities. Current treatment strategies involve lifestyle changes. Other surgical and pharmacologic interventions have been proposed; however, limited randomised controlled trials (RCTs) in the paediatric population restrict their use. AIM: To review the current management of paediatric NAFLD, including lifestyle and pharmacologic interventions, and to formulate recommendations for study design for future studies. METHODS: A MEDLINE, Pubmed and Cochrane Review database search used a combination of keywords, including NAFLD, nonalcoholic steatohepatitis (NASH), paediatric, treatments, lifestyle changes, bariatric surgery, orlistat, metformin, thiazolidinediones, vitamin E, cysteamine bitartrate, ursodeoxycholic acid (UDCA), probiotics, omega-3 fatty acids, pentoxyfylline, farnesoid X receptor agonist and toll-like receptor modifiers. The articles were selected based on their relevance to the review. RESULTS: Lifestyle interventions involving diet and exercise remain first-line treatment for paediatric NAFLD. Bariatric surgery, orlistat, insulin sensitisers and UDCA have been evaluated but are not recommended as first or second-line therapy. Medications such as cysteamine bitartrate, probiotics, polyunsaturated fats and pentoxyfilline share beneficial effects in trials, however, there is a paucity of adequately powered RCTs in which liver histology is evaluated. Vitamin E has been shown to be effective and safe in improving NASH histology in children. CONCLUSIONS: Lifestyle intervention should be first-line treatment for paediatric NAFLD. Vitamin E should be considered for those with biopsy-proven NASH or borderline NASH failing first-line therapy. Other therapeutics show promising results but require larger RCTs with convincing endpoints. Improved screening techniques, objective validated inclusion criteria and outcome measures as well as rigour in study design are necessary for propelling therapeutic discovery.

Enteric-coated cysteamine for the treatment of paediatric non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a common cause of liver disease in children. Hepatic fat accumulation and oxidative stress contribute to its pathogenesis. Cysteamine bitartrate readily traverses cellular membranes and is a potent antioxidant. AIM: To evaluate the safety and efficacy of enteric-coated (EC) cysteamine in children with NAFLD. METHOD: Children, aged ≥10 y, meeting screening criteria with biopsy-proven NAFLD and serum ALT ≥60 IU/L, received twice-daily EC-cysteamine for 24 weeks. Monthly ALT, AST, body mass index (BMI) and gastrointestinal symptom scores were measured. Subjects with >50% reduction or normalisation of ALT achieved the primary endpoint. RESULTS: Of the 13 children enrolled (mean age 14.0 years), 11 completed EC-cysteamine therapy (mean dose 15.2 mg/kg/day) and were included in the final analysis. For these 11 subjects, the mean ALT levels at baseline and 24 weeks were 120.2 and 55 IU/L respectively (P = 0.002), and the AST levels were 60 and 36 IU/L respectively (P = 0.007). The primary endpoint was reached in 7 and normalisation (≤40 IU/L) of ALT in 5. After 24 week therapy, mean adiponectin levels increased (P = 0.009) and CK-18 fragment levels decreased (P = 0.013), insulin levels remained unchanged (P = 0.99). Mean leptin levels were decreased in responders (P = 0.044). Mean BMI was 34.5 at baseline and 34.2 kg/m(2) after treatment (P = 0.35). Mean symptom scores at baseline (1.1) and at 24 weeks (0.7) were similar. No major adverse events were reported. CONCLUSIONS: Enteric-coated cysteamine reduces ALT and AST levels in children with NAFLD without reduction in body mass index. Further studies will evaluate optimal cysteamine therapeutic dose and effect on liver histology in NAFLD (Clinicaltrials.gov protocol ID: 07-1699).

Review article: epidemiology, pathogenesis and potential treatments of paediatric non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of paediatric liver disease. Similar to NAFLD in adults, NAFLD in children is associated with obesity and insulin resistance and requires liver histology for diagnosis and staging. However, significant histological differences exist between adult and paediatric NAFLD to warrant caution in extrapolation of adult data. AIM: To review the available data on the epidemiology, pathogenesis, diagnosis and treatment of paediatric NAFLD. METHODS: Relevant articles were identified by Medline searches using the keywords: nonalcoholic fatty liver disease, steatohepatitis, obesity and children. RESULTS: The rise in childhood obesity has been accompanied by an increase in paediatric NAFLD. Age, gender and race/ethnicity are significant determinants of risk, and sex hormones, insulin sensitivity and adipocytokines are implicated in the pathogenesis of paediatric NAFLD. There is no consensus for treatment of NAFLD; however, data suggest that diet, exercise and some pharmacological therapies may be of benefit. CONCLUSIONS: To evaluate and effectively treat paediatric NAFLD, the pathophysiology and natural history of the disease should be clarified and non-invasive methods for screening, diagnosis, and longitudinal assessment developed. Randomized, controlled, double-blind trials of pharmacological therapies in children with biopsy-proven disease are necessary.

A phase 2 clinical trial of metformin as a treatment for non-diabetic paediatric non-alcoholic steatohepatitis.

BACKGROUND: Children with non-alcoholic steatohepatitis are insulin-resistant and metformin has been proposed as a potential therapy. However, paediatric safety and efficacy data are absent. AIM: To test the hypothesis that metformin therapy will safely improve markers of liver disease in paediatric non-alcoholic steatohepatitis. METHODS: Single-arm open-label pilot study of metformin 500 mg twice daily for 24 weeks in non-diabetic children with biopsy-proven non-alcoholic steatohepatitis. RESULTS: Ten obese children (mean body mass index 30.4) enrolled and completed the trial. Mean alanine aminotransferase and aspartate aminotransferase (AST) improved significantly (P < 0.01) from baseline (184, 114 U/L) to end of treatment (98, 68 U/L). Alanine aminotransferase normalized in 40% and AST normalized in 50% of subjects. Children demonstrated significant improvements in liver fat measured by magnetic resonance spectroscopy (30-23%, P < 0.01); insulin sensitivity measured by quantitative insulin sensitivity check index (0.294-0.310, P < 0.05); and quality of life measured by pediatric quality of life inventory 4.0 (69-81, P < 0.01). CONCLUSION: Open-label treatment with metformin for 24 weeks was notable for improvement in liver chemistry, liver fat, insulin sensitivity and quality of life. A large randomized-controlled trial is needed to definitively determine the efficacy of metformin for paediatric non-alcoholic steatohepatitis.

Ranitidine, 75 mg, over-the-counter dose: pharmacokinetic and pharmacodynamic effects in children with symptoms of gastro-oesophageal reflux.

BACKGROUND: The use of over-the-counter antacids has increased in children under the age of 12 years, and has been followed by an apparent increase in the use of over-the-counter histamine-2 receptor antagonists. However, the pharmacokinetic and pharmacodynamic effects of over-the-counter histamine-2 receptor antagonists in the paediatric population are largely unknown. AIM: To evaluate the pharmacokinetics and pharmacodynamics of a single dose of the over-the-counter histamine-2 receptor antagonist, ranitidine, 75 mg, in children with symptoms of gastro-oesophageal reflux disease. METHODS: Children aged between 4 and 11 years with symptoms of heartburn suspected to be due to gastro-oesophageal reflux disease were recruited at six clinical centres. Following a single dose of either oral ranitidine, 75 mg (n=19), or placebo (n=10), recording of intragastric pH and serial blood sampling were carried out for 6 h. RESULTS: The estimated pharmacokinetic parameters of ranitidine, 75 mg, were as follows: the median Cmax value of 477 ng/mL occurred within a median of 2.5 h after dosing, and the median half-life was 2.0 h. The intragastric pH began to rise approximately 30 min after dosing with ranitidine to a peak of pH; 4. The pH in the ranitidine group remained higher than that in the placebo group throughout the 6-h evaluation period. Adverse events were generally mild. CONCLUSIONS: Ranitidine, 75 mg, significantly increased the intragastric pH in children aged 4-11 years. The pharmacokinetic and pharmacodynamic profiles were similar to those in adults. Ranitidine, 75 mg, appears to be effective for the control of intragastric acidity for 5-6 h in children aged 4-11 years.

Integral role of interventional radiology in the development of a pediatric liver transplantation program.

The aim of this study was to examine the role of interventional radiology (IR) in the pretransplant evaluation of potential living-related liver transplantation (LRLT) donors and in the post-transplant management of pediatric liver transplant recipients. Medical records and procedural reports were reviewed of 12 potential donors and five recipients for left lateral segment liver transplants. Procedures performed by the IR Division, clinical indications, and complications were tabulated. Retrospective calculation of radiation exposure to the skin and gonads of the donors and recipients were made. Three-dimensional ultrasound (3D US) was used in all 12 potential donors to screen for the donor with the most appropriately sized left lateral segment. The four optimal donor candidates underwent contrast angiography in order to measure the diameter and screen for variant arterial supply to the left lateral segment. Pretransplantation, one recipient underwent mesenteric angiography with indirect portography to confirm thrombosis of the portal vein and to prove patency of the splenomesenteric venous confluence. Three children underwent LRLT and two children received split livers from cadaveric donors. Thirty-two IR procedures were performed after transplantation (Tx) in the four transplant survivors (one child died following Tx). These IR procedures included: ultrasound-guided percutaneous liver biopsy to evaluate the pathologic cause of liver dysfunction (seven); placement of nasal jejunal feeding tubes (three) or a peripherally inserted central catheter (four) for nutritional and pharmacologic support; large-volume diagnostic and therapeutic paracentesis (two) and thoracentesis (one); percutaneous catheter drainage of symptomatic large pleural effusions (two), large-volume chylous ascites (one) (with later drain removal [one]), and a large biloma (one); percutaneous biliary drain placement (three), biliary drain replacement (two), and balloon cholangioplasty (four) to relieve obstructive jaundice from biliary enteric anatomic strictures; and mesenteric arteriography (one) for suspected thrombosis of the hepatic artery. No complications occurred. Mean skin and gonadal radiation doses were 193 mGy and 27 mGy, respectively, for donors, and 164 mGy and 60 mGy, respectively, for recipients. Even in a program such as this, with a limited series of pediatric liver Txs, it is apparent that IR plays an integral role in optimizing the clinical outcome and use of resources. Specific benefits included: selection of optimal donors; accurate mapping of the donor and occasionally recipient hepatic vasculature; and, most importantly, providing relatively safe minimally invasive procedures for nutritional support and diagnosis and management of untoward events after Tx. When possible, ultrasound guidance should be used to avoid excessive cumulative fluoroscopic exposure to recipients.

Germline characterization of early-aged onset of hereditary non-polyposis colorectal cancer.

OBJECTIVES: Hereditary non-polyposis colorectal cancer (HNPCC) is characterized by the early onset of colorectal cancer (approximately 40 years). Adolescent colorectal cancer is unusual in HNPCC families. We speculated that some DNA mismatch repair germline mutations might be associated with early onset of disease. STUDY DESIGN: Genomic DNA was extracted from members of a kindred with virulent HNPCC fitting the Amsterdam Criteria for HNPCC and sequenced for 2 DNA mismatch repair genes, hMSH2 and hMLH1. A sigmoid adenocarcinoma from the 14-year-old proband was analyzed for highfrequency microsatellite instability and immunostained for DNA mismatch repair gene expression. RESULTS: A germline mutation was identified at nucleotide 676 (codon 226) of the hMLH1 gene. The C to T transition created a nonsense mutation, truncating the hMLH1 protein. This mutation also alters the splice donor sequence, because nucleotide 676 is 2 base pairs from the 3' end of the exon 8. The proband's tumor demonstrated high-frequency microsatellite instability and displayed loss of hMLH1 expression, indicating bi-allelic inactivation of hMLH1. CONCLUSIONS: A complex mutation of hMLH1 at codon 226 is associated with adolescent onset of colorectal cancer in an HNPCC family. Genetic screening of other suspected HNPCC families with unusually young members with cancer might reveal certain genotypes with particularly virulent forms of this disease.

Vitamin E treatment of nonalcoholic steatohepatitis in children: a pilot study.

AIM: To determine whether supplemental oral vitamin E is effective in lowering serum aminotransferase and alkaline phosphatase levels in children with nonalcoholic steatohepatitis (NASH) associated with obesity. STUDY DESIGN: Open-label pilot study enrolling all children <16 years old with chronically elevated serum aminotransferase (alanine aminotransferase and aspartate aminotransferase) levels for greater than 3 months, who demonstrated a diffusely echogenic liver on ultrasonography, had no demonstrable reason for abnormal serum chemistry values other than obesity, and therefore were diagnosed to have NASH. Patients were prescribed oral vitamin E between 400 and 1200 IU per day. Serum chemistry values were monitored monthly during treatment. RESULTS: Eleven subjects with a mean age of 12.4 years were enrolled; treated patients were followed up for 4 to 10 months. The body mass index did not change significantly before and after treatment (32.8 +/- 3.8 kg/m(2) vs 32.5 +/- 4.4 kg/m(2), respectively). Serum alanine aminotransferase decreased from 175 +/- 106 IU/L to 40 +/- 26 IU/L (P <.001, paired Student t test), serum aspartate aminotransferase decreased from 104 +/- 61 IU/L to 33 +/- 11 IU/L (P <.002), and alkaline phosphatase decreased from 279 +/- 42 IU/L to 202 +/- 66 IU/L (P <.003) during treatment. Serum aminotransferase levels remained normal during treatment but returned to abnormal in those electing to stop treatment. Serum alpha-tocopherol levels were within the normal range before the commencement of therapy and increased significantly with supplementation. The liver remained diffusely echogenic during therapy, at the time serum aminotransferase levels were reduced. CONCLUSIONS: Daily oral vitamin E administration normalized serum aminotransferase and alkaline phosphatase levels in children with NASH. Obese children with NASH should be encouraged to lose weight as part of a comprehensive weight reduction program and to consider taking supplemental alpha-tocopherol.

Genetic heterogeneity in familial juvenile polyposis.

Juvenile polyposis syndrome (JPS) is an autosomal dominant syndrome characterized by multiple gastrointestinal hamartomatous polyps in the absence of the extraintestinal features that are classic for other hamartomatous polyposis syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden disease (CD). About 50% of BRRS and >80% of CD demonstrate germ-line mutations in the tumor suppressor and dual phosphatase, PTEN. Germ-line mutation of PTEN as a cause for JPS in a child is controversial because extraintestinal manifestations that would exclude JPS could appear after adolescence, altering the clinical diagnosis. Here, we investigated a family in which the 55-year-old father, who lacks thyroid or skin findings characteristic of CD, demonstrated a germ-line mutation in PTEN that was passed to identical twin daughters, who both manifested JPS. The mutation was a deletion of five bases beginning seven bases from the start of exon 4 of PTEN, which caused aberrant transcripts by reverse transcription-PCR that were absent from a normal individual. Thus, mutations in PTEN are associated with JPS in addition to CD and some BRRS families, although the incidence of PTEN germ-line mutations in JPS might be more rare than that reported for SMAD4, a gene found to be mutated in approximately one-half of the JPS families investigated.

Absence of PTEN/MMAC1 germ-line mutations in sporadic Bannayan-Riley-Ruvalcaba syndrome.

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare hamartomatous polyposis condition with features of macrocephaly, intestinal juvenile polyposis, developmental delay, lipomas, and pigmentation spots of the male genitalia. An autosomal dominant pattern of inheritance exists in some families, but others appear as sporadic cases. Germ-line mutations in PTEN, a tyrosine phosphatase and putative tumor suppressor gene, have been demonstrated in two families with BRRS, and chromatin loss at the PTEN gene locus on chromosome 10q23 has been demonstrated in two BRRS patients. Germ-line mutations in PTEN have also been described in Cowden disease and in a small number of patients with juvenile polyposis syndrome. In an attempt to assess the nature of PTEN mutations in BRRS, we analyzed three sporadic BRRS patients for chromosome 10q23 deletion or PTEN germ-line mutations. All 3 patients demonstrated no loss of parental alleles at 15 chromosome 10q23 markers that encompassed the region of PTEN. In addition, analysis of mRNA and genomic DNA revealed no nonsense, missense, or insertion/deletion mutations of PTEN. Thus, other mechanisms besides mutation of PTEN must have occurred to cause BRRS in these patients. We speculate that BRRS and juvenile polyposis syndrome may have a heterogeneous etiology to cause their syndromes.

Localization of the Bannayan-Riley-Ruvalcaba syndrome gene to chromosome 10q23.

BACKGROUND & AIMS: Bannayan-Riley-Ruvalcaba syndrome is a congenital syndrome with characteristic features of macrocephaly, cognitive and motor dysfunction, subcutaneous and visceral lipomas and hemangiomas, and intestinal juvenile polyposis. It has been suggested that Bannayan-Riley-Ruvalcaba syndrome may be a variant of juvenile polyposis coli because of the shared features of intestinal juvenile polyps. The aim of this study was to precisely map loss of DNA from 2 patients with intestinal juvenile polyposis and karyotypic abnormalities involving chromosome 10q. METHODS: DNA was extracted from peripheral leukocytes drawn from each patient and each patient's biological parents. The DNA was amplified by polymerase chain reaction using primers specific for microsatellites located on chromosome 10q. RESULTS: Precise mapping localized a maximal distance of 1.0 cM that was commonly deleted from each patient's genome, between D10S541 and D10S1735. This area overlaps the region for Cowden disease, a distinct hamartomatous intestinal polyposis syndrome with increased risk of breast and thyroid carcinoma. CONCLUSIONS: The three hamartomatous polyposis syndromes, Bannayan-Riley-Ruvalcaba syndrome, juvenile polyposis coli, and Cowden disease, may share the same genetic defect because of their common map localization to chromosome 10q23.

Update on viral hepatitis in children.

Recent discovery of the two major agents responsible for non-A, non-B hepatitis has led to rapid progress in the diagnosis and prevention of viral hepatitis. Newly implemented vaccine strategies against hepatitis A and hepatitis B are protecting children from infection, and new immunomodulatory therapy with interferon-alpha is being used to eradicate disease in patients chronically infected with hepatitis virus B or C.

Cytokine inhibition of the hepatitis B virus core promoter.

Hepatitis B virus (HBV) DNA contains consensus elements for transactivating proteins whose binding activity in other systems is regulated by inflammatory cytokines. Because HBV replicates within an environment of provoked inflammation, we speculated that the HBV core/pregenomic promoter may be regulated by cytokines produced in response to infection. To evaluate this hypothesis, the HBV core/pregenomic (C/P) promoter and associated cis-acting elements were placed upstream of a luciferase-encoding plasmid. This reporter construct was transfected into cytokine-sensitive hepatoma cells permissive for HBV replication, which were exposed to stimulated mononuclear cell-conditioned medium or human recombinant cytokines. Conditioned medium reduced luciferase expression by 80%. Tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and interferon alfa (IFN-alpha) each reduced luciferase activity by 40%. Combinations of TNF-alpha and interferons mimicked the extent of conditioned medium inhibition. Non-specific effects from diminished cellular viability or growth were not responsible for decreased luciferase activity. Retention of HBV DNA 330 basepairs upstream of the C/P transcription start site was required to maintain the TNF-alpha effect. A 60% reduction in HBV replicative forms within intracellular core particles was demonstrated with TNF-alpha treatment of Hep G2 cells stably transfected with HBV DNA. The inhibitory action of these cytokines implicates a noncytolytic mechanism by which antigen-nonspecific immune responses in part regulate HBV replication in infected hepatocytes. This function may be beneficial in accelerating viral clearance, but in alternative circumstances could contribute to viral persistence by attenuating immunogen recognition.

Idiopathic steatohepatitis in childhood: a multicenter retrospective study.

OBJECTIVE: To describe the clinical, laboratory, and histopathologic features of idiopathic steatohepatitis in children. STUDY DESIGN: Retrospective review of all liver biopsies performed at Boston Children's Hospital, Massachusetts General Hospital, and the University of Massachusetts Medical Center from 1991 to 1994. Chart review was performed when biopsies demonstrated steatosis. RESULTS: Eighty-two patients had biopsy-proven hepatic steatosis. Fourteen patients had fatty liver without evidence of inherited, infectious, autoimmune, endocrinologic, toxicologic, or iatrogenic causes. All 14 patients were obese, averaging 159% of ideal body weight (range, 121% to 222%). Nine patients initially had transient abdominal pain, two had hepatomegaly, and one was identified by incidental laboratory evaluation. These 12 patients had biopsies because of persistent elevations of aminotransferase levels. Two other patients without risk factors for steatosis were identified at staging laparotomy for Hodgkin lymphoma. The 10 boys and 4 girls had an average age of 13.5 years (range, 10 to 18 years). Aminotransferase elevations were modest, with aspartate aminotransferase and alanine aminotransferase values averaging 77 +/- 38 IU and 129 +/- 73 IU, respectively. All had imaging studies demonstrating diffuse fatty change. Histologic examination of biopsy specimens revealed varying degrees of steatosis with inflammation and fibrosis. CONCLUSION: Idiopathic steatohepatitis occurs predominantly or exclusively in obese peripubertal children. This entity represents a frequent reason for liver biopsy in this age group. The degree of steatosis, fibrosis, and inflammation does not correlate with symptoms or signs, and significant liver injury with bridging fibrosis may be present.