Investigating the Relationship Between Rare Genetic Variants and Fibrosis in Pediatric Nonalcoholic Fatty Liver Disease.

Background and Aims: Nonalcoholic Fatty Liver Disease (NAFLD) is a complex human disease. Common genetic variation in the patatin-like phospholipase domain containing 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) genes have been associated with an increased risk of developing NAFLD, nonalcoholic steatohepatitis (NASH), and fibrosis in adults. The role of rare genetic variants in the development and progression of NAFLD in children is not well known. We aimed to explore the role of rare genetic variants in pediatric patients with advanced fibrosis. Methods: Whole exome sequencing data was generated for 229 pediatric patients diagnosed with NAFLD recruited from the NASH Clinical Research Network (NASH CRN). Case-control single variant and gene-based collapsing analyses were used to test for rare variants that were enriched or depleted within the pediatric NAFLD cohort specifically for advanced fibrosis (cases) versus those without fibrosis (controls) or six other histologic characteristics. Exome data from non-NAFLD population controls were also used for additional analyses. All results were adjusted for multiple testing using a Bonferroni correction. Results: No genome-wide significant associations were found between rare variation and presence of advanced fibrosis or NASH, nor the severity of steatosis, inflammation, or hepatocellular ballooning. Significantly, no enrichment of rare variants in PNPLA3 or TM6SF2 was observed across phenotypes. Conclusion: In a cohort of children with histologically proven NAFLD, no genome-wide significant associations were found between rare genetic variation and advanced fibrosis or six other histologic features. Of particular interest was the lack of association with genes of interest in adults: PNPLA3 and TM6SF2, though limitations in sample size may reduce the ability to detect associations, particularly with rare variation.

The diagnostic yield of exome sequencing in liver diseases from a curated gene panel.

Exome sequencing (ES) has been used in a variety of clinical settings but there are limited data on its utility for diagnosis and/or prediction of monogenic liver diseases. We developed a curated list of 502 genes for monogenic disorders associated with liver phenotypes and analyzed ES data for these genes in 758 patients with chronic liver diseases (CLD). For comparison, we examined ES data in 7856 self-declared healthy controls (HC), and 2187 patients with chronic kidney disease (CKD). Candidate pathogenic (P) or likely pathogenic (LP) variants were initially identified in 19.9% of participants, most of which were attributable to previously reported pathogenic variants with implausibly high allele frequencies. After variant annotation and filtering based on population minor allele frequency (MAF ≤ 10-4 for dominant disorders and MAF ≤ 10-3 for recessive disorders), we detected a significant enrichment of P/LP variants in the CLD cohort compared to the HC cohort (X2 test OR 5.00, 95% CI 3.06-8.18, p value = 4.5e-12). A second-level manual annotation was necessary to capture true pathogenic variants that were removed by stringent allele frequency and quality filters. After these sequential steps, the diagnostic rate of monogenic disorders was 5.7% in the CLD cohort, attributable to P/LP variants in 25 genes. We also identified concordant liver disease phenotypes for 15/22 kidney disease patients with P/LP variants in liver genes, mostly associated with cystic liver disease phenotypes. Sequencing results had many implications for clinical management, including familial testing for early diagnosis and management, preventative screening for associated comorbidities, and in some cases for therapy. Exome sequencing provided a 5.7% diagnostic rate in CLD patients and required multiple rounds of review to reduce both false positive and false negative findings. The identification of concordant phenotypes in many patients with P/LP variants and no known liver disease also indicates a potential for predictive testing for selected monogenic liver disorders.

AGA Clinical Practice Update on the Role of Noninvasive Biomarkers in the Evaluation and Management of Nonalcoholic Fatty Liver Disease: Expert Review.

DESCRIPTION: The purpose of this American Gastroenterological Association (AGA) Clinical Practice Update Expert Review is to provide clinicians with guidance on the use of noninvasive tests (NITs) in the evaluation and management of patients with nonalcoholic fatty liver disease (NAFLD). NAFLD affects nearly 30% of the global population and is a growing cause of end-stage liver disease and liver-related health care resource utilization. However, only a minority of all patients with NAFLD experience a liver-related outcome. It is therefore critically important for clinicians to assess prognosis and identify those with increased risk of disease progression and negative clinical outcomes at the time of initial assessment. It is equally important to assess disease trajectory over time, particularly in response to currently available therapeutic approaches. The reference standard for assessment of prognosis and disease monitoring is histologic examination of liver biopsy specimens. There are, however, many limitations of liver biopsies and their reading that have limited their use in routine practice. The utilization of NITs facilitates risk stratification of patients and longitudinal assessment of disease progression for patients with NAFLD. This clinical update provides best practice advice based on a review of the literature on the utilization of NITs in the management of NAFLD for clinicians. Accordingly, a combination of available evidence and consensus-based expert opinion, without formal rating of the strength and quality of the evidence, was used to develop these best practice advice statements. METHODS: This Expert Review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. These best practice advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these best practice advice statements do not carry formal ratings of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: NITs can be used for risk stratification in the diagnostic evaluation of patients with NAFLD. BEST PRACTICE ADVICE 2: A Fibrosis 4 Index score <1.3 is associated with strong negative predictive value for advanced hepatic fibrosis and may be useful for exclusion of advanced hepatic fibrosis in patients with NAFLD. BEST PRACTICE ADVICE 3: A combination of 2 or more NITs combining serum biomarkers and/or imaging-based biomarkers is preferred for staging and risk stratification of patients with NAFLD whose Fibrosis 4 Index score is >1.3. BEST PRACTICE ADVICE 4: Use of NITs in accordance with manufacturer's specifications (eg, not in patients with ascites or pacemakers) can minimize risk of discordant results and adverse events. BEST PRACTICE ADVICE 5: NITs should be interpreted with context and consideration of pertinent clinical data (eg, physical examination, biochemical, radiographic, and endoscopic) to optimize positive predictive value in the identification of patients with advanced fibrosis. BEST PRACTICE ADVICE 6: Liver biopsy should be considered for patients with NIT results that are indeterminate or discordant; conflict with other clinical, laboratory, or radiologic findings; or when alternative etiologies for liver disease are suspected. BEST PRACTICE ADVICE 7: Serial longitudinal monitoring using NITs for assessment of disease progression or regression may inform clinical management (ie, response to lifestyle modification or therapeutic intervention). BEST PRACTICE ADVICE 8: Patients with NAFLD and NITs results suggestive of advanced fibrosis (F3) or cirrhosis (F4) should be considered for surveillance of liver complications (eg, hepatocellular carcinoma screening and variceal screening per Baveno criteria). Patients with NAFLD and NITs suggestive of advanced hepatic fibrosis (F3) or (F4), should be monitored with serial liver stiffness measurement; vibration controlled transient elastography; or magnetic resonance elastography, given its correlation with clinically significant portal hypertension and clinical decompensation.

Using epigenomics to understand cellular responses to environmental influences in diseases.

It is a generally accepted model that environmental influences can exert their effects, at least in part, by changing the molecular regulators of transcription that are described as epigenetic. As there is biochemical evidence that some epigenetic regulators of transcription can maintain their states long term and through cell division, an epigenetic model encompasses the idea of maintenance of the effect of an exposure long after it is no longer present. The evidence supporting this model is mostly from the observation of alterations of molecular regulators of transcription following exposures. With the understanding that the interpretation of these associations is more complex than originally recognised, this model may be oversimplistic; therefore, adopting novel perspectives and experimental approaches when examining how environmental exposures are linked to phenotypes may prove worthwhile. In this review, we have chosen to use the example of nonalcoholic fatty liver disease (NAFLD), a common, complex human disease with strong environmental and genetic influences. We describe how epigenomic approaches combined with emerging functional genetic and single-cell genomic techniques are poised to generate new insights into the pathogenesis of environmentally influenced human disease phenotypes exemplified by NAFLD.

Hepatocellular Carcinoma in Hispanic Patients: Trends and Outcomes in a Large United States Cohort.

Hepatocellular carcinoma (HCC) has a strong racial and ethnic association, with Hispanic patients having a higher incidence and mortality. However, there are limited data regarding clinical features and outcomes. This study includes Hispanic and non-Hispanic White patients with HCC diagnosed between January 2000 and June 2014 from five United States academic medical centers. The chi-square test for categorical variables and analysis of variance for continuous variables were used for statistical analysis, with two-tailed P < 0.05 considered statistically significant. Of 5,327 patients, 4,217 met inclusion criteria, of whom 12.3% were Hispanic patients. Compared to their non-Hispanic White counterparts, Hispanic patients were older at age of diagnosis (mean ± SD, 64.2 ± 10.9 vs. 61.9 ± 10.5 years; P < 0.0001), with higher body mass index (29.6 ± 6.5 vs. 28.8 ± 5.9 kg/m2; P = 0.01), and were more likely to have diabetes and hypertension. Hispanic patients had significantly more nonalcoholic fatty liver disease and alcohol-related liver disease (both P < 0.0001). Hispanic patients presented with larger tumors, more advanced stage disease, and increased rates of macrovascular invasion and extrahepatic spread. HCCs in Hispanic patients were less likely to be within Milan criteria (26% vs. 38%; P < 0.0001) and were less likely to be treated with resection (9% vs. 13%; P = 0.03) or transplantation (8% vs. 19%; P < 0.0001). Hispanic patients had a median overall survival of 1.4 years (95% confidence interval [CI], 1.22-1.56), which was similar to that of non-Hispanic White patients (1.3 years; 95% CI, 1.26-1.41; P = 0.07). Conclusion: Hispanic patients with HCC were more likely to have metabolic risk factors for chronic liver disease, including obesity. Despite diagnosis at more advanced stages with less curative intervention than non-Hispanic White patients, median overall survival was similar between groups.

Non-alcoholic fatty liver disease (NAFLD) in non-obese individuals.

Individuals with non-alcoholic fatty liver disease (NAFLD) who lack classical risk factors also have the ability to develop nonalcoholic steatohepatitis (NASH) and progression to more advanced liver disease. The pathophysiology and risk factors for the development of NAFLD in non-obese persons are not fully understood but seem to be closely related to insulin resistance, atherogenic dyslipidaemia and alterations in body composition, with some patients harbouring predisposing genetic polymorphisms. In normal-weight individuals, also called 'lean', there is limited potential for effective lifestyle change in disease management. Additionally, biological mechanisms underlying the development of NASH in non-obese individuals may reveal novel targets for intervention. In this review, the authors discuss the clinical, histological and genetic features and risk factors for non-obese NAFLD and highlight gaps in knowledge and areas for future research.

Distinctive Features and Outcomes of Hepatocellular Carcinoma in Patients With Alcohol-Related Liver Disease: A US Multicenter Study.

INTRODUCTION: The burden of hepatocellular carcinoma (HCC) occurring in patients with alcoholic liver disease (ALD) is increasing at an alarming rate. The aims of this study were to compare the patient and tumor characteristics of HCC occurring in ALD-alone relative to and in addition to other chronic liver diseases. METHODS: Patients diagnosed with HCC between 2000 and 2014 were identified at 5 US clinical centers. The patients were categorized as ALD-alone, ALD plus viral hepatitis, or a non-ALD etiology. Clinical and tumor characteristics among the 3 groups were compared, and survival probability was estimated by the Kaplan-Meier method. The frequency of noncirrhotic HCC was compared across the 3 groups. RESULTS: A total of 5,327 patients with HCC were analyzed. Six hundred seventy (12.6%) developed HCC due to underlying ALD. Ninety-one percent of ALD-related HCC arose in men, in contrast to non-ALD etiologies where men accounted for 70% of HCCs cases (P < 0.001). Patients with ALD-alone-related HCC were older at diagnosis and had tumors less likely to be detected as part of routine surveillance. The ALD-alone cohort was least likely to be within the Milan criteria and to undergo liver transplantation. Overall survival in the ALD-alone HCC cohort was lower than the other 2 groups (1.07 vs 1.31 vs 1.41 years, P < 0.001). HCC in the noncirrhotic ALD cohorts occurred in only 3.5% of the patients compared with 15.7% in patients with non-ALD etiologies (P < 0.001). DISCUSSION: HCC occurring in patients with ALD occurred mostly in older men and almost exclusively in a cirrhotic background. They present with advanced tumors, and their survival is lower than HCCs occurring in non-ALD.

Gender Matters: Characteristics of Hepatocellular Carcinoma in Women From a Large, Multicenter Study in the United States.

INTRODUCTION: Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide, affecting men to women at a ratio of about 4:1. Risk factors, characteristics, and outcomes for HCC in women in the United States remain poorly understood; therefore, we aim to explore gender differences further. METHODS: Patients diagnosed with HCC between January 2000 and June 2014 at 5 large centers were identified. Clinical information, tumor characteristics, and survival data were extracted manually. The presence of underlying cirrhosis was assessed based on published criteria. RESULTS: Of 5,327 patients with HCC in our cohort, 1,203 (22.6%) were women. There were important differences in the underlying etiology of liver disease between the 2 genders (P < 0.0001): women had a significantly higher frequency of nonalcoholic fatty liver disease (23% vs 12%) and lower frequency of alcoholic liver disease (5% vs 15%). The proportion of noncirrhotic HCC was significantly higher among women (17% vs 10%, P < 0.0001). Women had less-advanced HCC at presentation by tumor, node, metastasis staging (P < 0.0001) and a higher proportion within Milan criteria (39% vs 35%, P = 0.002). Women had a greater overall survival (2.5 ± 2.9 years vs 2.2 ± 2.7 years, P = 0.0031). DISCUSSION: The frequency of underlying nonalcoholic fatty liver disease and noncirrhotic HCC were significantly higher in women than men in this large cohort. Women presented with less-advanced HCC and had a greater overall survival. Further investigation is warranted to explore potential mechanisms and implications for these gender differences, especially with noncirrhotic HCC (see Visual Abstract, Supplementary Digital Content 1, http://links.lww.com/AJG/B535).

Extrahepatic Manifestations of Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) represents a global public health burden. NAFLD, while strongly associated with the metabolic syndrome, can occur independently from existing metabolic diseases. In addition to liver-related disease burden and mortality, significant extrahepatic disease outcomes coexist with NAFLD, including cardiovascular diseases, chronic kidney disease, and type 2 diabetes. Management of these comorbidities contributes to the overall public health burden of NAFLD. These extrahepatic manifestations require healthcare interventions that are vigilant in monitoring for progression of liver disease while simultaneously managing overall morbidity and mortality from other organ systems.

Impact of obeticholic acid on the lipoprotein profile in patients with non-alcoholic steatohepatitis.

BACKGROUND & AIMS: Obeticholic acid (OCA), a farnesoid X receptor agonist, increases total and low-density lipoprotein cholesterol (LDL-C) in patients with non-alcoholic steatohepatitis. In the present study, we aimed to evaluate the impact of OCA therapy on lipoprotein sub-particles. METHOD: This study included 196 patients (99 OCA group and 97 placebo group) who were enrolled in the FLINT trial and had samples available for lipid analysis and liver biopsies at enrollment and end-of-treatment (EOT) at 72 weeks. Very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) particles were evaluated at baseline, 12 and 72 weeks after randomization, and 24 weeks following EOT. RESULTS: Baseline lipoprotein profiles were similar among OCA and placebo groups. OCA did not affect total VLDL particle concentrations, but OCA vs. placebo treatment was associated with decreased large VLDL particle concentration at 12 weeks (baseline-adjusted mean: 6.8 vs. 8.9 nmol/L; p = 0.002), mirrored by an increase in less atherogenic, small VLDL particle concentration (33.9 vs. 28.0 nmol/L; p = 0.02). After 12 weeks, total LDL particle concentration was higher in the OCA group than the placebo group (1,667 vs. 1,329 nmol/L; p <0.0001), characterized by corresponding increases in both less atherogenic, large-buoyant LDL (475 vs. 308 nmol/L; p ≤0.001) and more atherogenic small-dense LDL particles (1,015 vs. 872 nmol/L; p = 0.002). The changes in LDL particle concentrations were similar between treatment groups (OCA and placebo) 24 weeks following EOT due to improvement in the OCA cohort. Compared to placebo, a reduction in total HDL particle concentration, particularly large and medium HDL particles, was noted in the OCA-treated patients, but this resolved after drug discontinuation. CONCLUSION: OCA therapy is associated with increases in small VLDL particles, large and small LDL particles, and a reduction in HDL particles at 12 weeks. These lipoprotein concentrations reverted to baseline values 24 weeks after drug discontinuation. LAY SUMMARY: Non-alcoholic steatohepatitis is a chronic liver disease that is associated with an increased risk of developing cirrhosis and cardiovascular disease. Recently, obeticholic acid (OCA), a farnesoid X receptor agonist, improved liver disease but led to an increase in cholesterol. However, the impact of OCA on cholesterol is not well understood. In the present study, we show that OCA therapy is associated with a detrimental increase in lipoprotein levels, which improves after drug discontinuation. ClinicalTrials.gov numbers: NCT01265498.

Characteristics, aetiologies and trends of hepatocellular carcinoma in patients without cirrhosis: a United States multicentre study.

BACKGROUND: Limited data exist on the burden and features of non-cirrhotic hepatocellular carcinoma (HCC) in the United States. AIM: To evaluate characteristics, aetiologies, trends and outcomes of non-cirrhotic HCC from 2000 to 2014 at five large US centres METHODS: Patient, tumour and liver disease aetiology data were collected. The presence of underlying cirrhosis was assessed based on published criteria. RESULTS: Of 5144 eligible patients with HCC, 11.7% had no underlying cirrhosis. Non-cirrhotic patients were older (64.1 vs 61.2 years), more frequently females (33.9% vs 20.8%) and less frequently black (8.3% vs 12.4%) (P < .001 for all). Among non-cirrhotic patients, non-alcoholic fatty liver disease (NAFLD) was the most common liver disease (26.3%), followed by hepatitis C virus (HCV) (12.1%) and hepatitis B virus (HBV) (10%) infections. As of 2014, there was increased percentage of cirrhotic HCC and a decline in non-cirrhotic HCC mainly due to significant annual increases in cirrhotic HCC due to HCV (0.96% [P < .0001]) and NAFLD (0.66% [P = .003]). Patients with non-cirrhotic HCC had larger tumours (8.9 vs 5.3 cm), were less frequently within Milan criteria (15% vs 39%), more frequently underwent resection (43.6% vs 8%) (P < .001 for all) and had better overall survival than cirrhotic HCC patients (median 1.8 vs 1.3 years, P = .004). CONCLUSIONS: Nearly 12% of HCCs occurred in patients without underlying cirrhosis. NAFLD was the most common liver disease in these patients. During the study, the frequency of non-cirrhotic HCC decreased, whereas that of cirrhotic HCC increased. Although non-cirrhotic patients presented with more advanced HCC, their survival was better.

Exome sequencing of an adolescent with nonalcoholic fatty liver disease identifies a clinically actionable case of Wilson disease.

Diagnostic whole-exome sequencing has proven highly successful in a range of rare diseases, particularly early-onset genetic conditions. In more common conditions, however, exome sequencing for diagnostic purposes remains the exception. Here we describe a patient initially diagnosed with a common, complex liver disease, nonalcoholic fatty liver disease (NAFLD), who was determined to have Wilson disease (WD) upon research-related exome sequencing. The patient presented as a 14.5-yr-old adolescent with chronically elevated aminotransferases, normal ceruloplasmin, and histologic examination consistent with NAFLD with advanced fibrosis. He was enrolled in a large longitudinal study of patients with NAFLD and was found to have WD by exome sequencing performed 4 yr later. This new diagnosis, confirmed clinically by 24 h urine copper quantification, led to a change in the therapy from lifestyle counseling to directed treatment with d-penicillamine, a copper chelating agent. In this case, the likelihood of making the correct diagnosis and thereby choosing the appropriate treatment was increased by exome sequencing and careful interpretation. This example illustrates the utility of exome sequencing diagnostically in more common conditions not currently considered as targets for genome-wide evaluation and adds to a growing body of evidence that patients diagnosed with more common conditions often in fact have rarer genetically determined syndromes that have escaped clinical detection.

Nonalcoholic Steatohepatitis (NASH) and Hepatic Fibrosis: Emerging Therapies.

Nonalcoholic fatty liver disease remains a major cause of liver-related morbidity and mortality worldwide. It is a complex disease associated with obesity, diabetes, and dyslipidemia but is increasingly recognized in normal-weight individuals. Its progressive inflammatory phenotype, nonalcoholic steatohepatitis (NASH), currently has no effective treatment apart from lifestyle interventions. Multiple pathogenic pathways are involved in disease progression, and targets for intervention have been identified. These targets mediate glucose, lipid, and bile acid metabolism; inflammation; apoptosis; and fibrosis. Novel therapeutic agents are being developed in each of these pathways, and several have shown promise in early phase testing. Given the complexity of the disease, intervention trials are large and long and require histologic confirmation as a primary endpoint for disease improvement or regression. We highlight active Phase 2 and 3 therapeutic trials for NASH as this field rapidly expands in development.

Genome-Wide Associations Related to Hepatic Histology in Nonalcoholic Fatty Liver Disease in Hispanic Boys.

OBJECTIVE: To identify genetic loci associated with features of histologic severity of nonalcoholic fatty liver disease in a cohort of Hispanic boys. STUDY DESIGN: There were 234 eligible Hispanic boys age 2-17 years with clinical, laboratory, and histologic data enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network included in the analysis of 624 297 single nucleotide polymorphisms (SNPs). After the elimination of 4 outliers and 22 boys with cryptic relatedness, association analyses were performed on 208 DNA samples with corresponding liver histology. Logistic regression analyses were carried out for qualitative traits and linear regression analyses were applied for quantitative traits. RESULTS: The median age and body mass index z-score were 12.0 years (IQR, 11.0-14.0) and 2.4 (IQR, 2.1-2.6), respectively. The nonalcoholic fatty liver disease activity score (scores 1-4 vs 5-8) was associated with SNP rs11166927 on chromosome 8 in the TRAPPC9 region (P = 8.7-07). Fibrosis stage was associated with SNP rs6128907 on chromosome 20, near actin related protein 5 homolog (p = 9.9-07). In comparing our results in Hispanic boys with those of previously reported SNPs in adult nonalcoholic steatohepatitis, 2 of 26 susceptibility loci were associated with nonalcoholic fatty liver disease activity score and 2 were associated with fibrosis stage. CONCLUSIONS: In this discovery genome-wide association study, we found significant novel gene effects on histologic traits associated with nonalcoholic fatty liver disease activity score and fibrosis that are distinct from those previously recognized by adult nonalcoholic fatty liver disease genome-wide association studies.

Treatment options for nonalcoholic steatohepatitis - a safety evaluation.

INTRODUCTION: There is an urgent as yet unmet need to develop highly effective and safe therapeutics for nonalcoholic fatty liver disease (NAFLD). The remarkable progress in understanding NAFLD pathogenesis allowed the identification of injury pathways which may be recruited as therapy targets. Areas covered: This article reviews the safety and tolerability data of the NAFLD therapies and explains the mechanistic basis for each of the established and investigational drugs. Treatment targets include: weight loss, anti-metabolic agents such as lipid lowering and anti-diabetic drugs, inflammation, fibrosis and others such as targeting gut microbiota, immune modulation and apoptosis. Expert opinion: Current therapies continue to remain suboptimal. Weight loss is effective but hard to achieve. Traditional and endoscopic bariatric procedures are promising although more randomized trials are needed and the long-term safety remains to be established. Clinical trials have demonstrated the efficacy of several drugs for the treatment of NASH. Of these, there remains some uncertainty about the long-term safety of vitamin E. Pioglitazone is associated with osteopenia, fluid retention and weight gain. Obeticholic acid causes pruritus in a substantial proportion of subjects and elafibranor has been associated with transient rises in creatinine. Several exciting therapies are under development and results of clinical and post-marketing trials will help elucidate their safety.

Non-alcoholic fatty liver disease phosphoproteomics: A functional piece of the precision puzzle.

BACKGROUND: Molecular signaling events associated with the necroinflammatory changes in nonalcoholic steatohepatitis (NASH) are not well understood. AIMS: To understand the molecular basis of NASH, we evaluated reversible phosphorylation events in hepatic tissue derived from Class III obese subjects by phosphoproteomic means with the aim of highlighting key regulatory pathways that distinguish NASH from non-alcoholic fatty liver disease (also known as simple steatosis; SS). MATERIALS & METHODS: Class III obese subjects undergoing bariatric surgery underwent liver biopsy (eight normal patients, eight with simple steatosis, and eight NASH patients). Our strategy was unbiased, comparing global differences in liver protein reversible phosphorylation events across the 24 subjects. RESULTS: Of the 3078 phosphorylation sites assigned (2465 phosphoserine, 445 phosphothreonine, 165 phosphotyrosine), 53 were altered by a factor of 2 among cohorts, and of those, 12 were significantly increased or decreased by ANOVA (P < 0.05). DISCUSSION: Statistical analyses of canonical signaling pathways identified carbohydrate metabolism and RNA post-transcriptional modification among the most over-represented networks. CONCLUSION: Collectively, these results raise the possibility of abnormalities in carbohydrate metabolism as an important trigger for the development of NASH, in parallel with already established abnormalities in lipid metabolism.

Risk factors for hepatocellular carcinoma in cirrhosis due to nonalcoholic fatty liver disease: A multicenter, case-control study.

AIM: To identify risk factors associated with hepatocellular carcinoma (HCC), describe tumor characteristics and treatments pursed for a cohort of individuals with nonalcoholic steatohepatitis (NASH) cirrhosis. METHODS: We conducted a retrospective case-control study of a well-characterized cohort of patients among five liver transplant centers with NASH cirrhosis with (cases) and without HCC (controls). RESULTS: Ninety-four cases and 150 controls were included. Cases were significantly more likely to be male than controls (67% vs 45%, P < 0.001) and of older age (61.9 years vs 58 years, P = 0.002). In addition, cases were more likely to have had complications of end stage liver disease (83% vs 71%, P = 0.032). On multivariate analysis, the strongest association with the presence of HCC were male gender (OR 4.3, 95%CI: 1.83-10.3, P = 0.001) and age (OR = 1.082, 95%CI: 1.03-1.13, P = 0.001). Hispanic ethnicity was associated with a decreased prevalence of HCC (OR = 0.3, 95%CI: 0.09-0.994, P = 0.048). HCC was predominantly in the form of a single lesion with regional lymph node(s) and distant metastasis in only 2.6% and 6.3%, respectively. Fifty-nine point three percent of individuals with HCC underwent locoregional therapy and 61.5% underwent liver transplantation for HCC. CONCLUSION: Male gender, increased age and non-Hispanic ethnicity are associated with HCC in NASH cirrhosis. NASH cirrhosis associated HCC in this cohort was characterized by early stage disease at diagnosis and treatment with locoregional therapy and transplant.