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TM6SF2 rs58542926 influences hepatic fibrosis progression in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an increasingly common condition, strongly associated with the metabolic syndrome, that can lead to progressive hepatic fibrosis, cirrhosis and hepatic failure. Subtle inter-patient genetic variation and environmental factors combine to determine variation in disease progression. A common non-synonymous polymorphism in TM6SF2 (rs58542926 c.449 C>T, p.Glu167Lys) was recently associated with increased hepatic triglyceride content, but whether this variant promotes clinically relevant hepatic fibrosis is unknown. Here we confirm that TM6SF2 minor allele carriage is associated with NAFLD and is causally related to a previously reported chromosome 19 GWAS signal that was ascribed to the gene NCAN. Furthermore, using two histologically characterized cohorts encompassing steatosis, steatohepatitis, fibrosis and cirrhosis (combined n=1,074), we demonstrate a new association, independent of potential confounding factors (age, BMI, type 2 diabetes mellitus and PNPLA3 rs738409 genotype), with advanced hepatic fibrosis/cirrhosis. These findings establish new and important clinical relevance to TM6SF2 in NAFLD.

Viral hepatitis and hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. The incidence of HCC varies considerably with the geographic area because of differences in the major causative factors. Chronic hepatitis B and C, mostly in the cirrhotic stage, are responsible for the great majority of cases of HCC worldwide. The geographic areas at the highest risk are South-East Asia and sub-Saharan Africa, here hepatitis B is highly endemic and is the main cause of HCC. In areas with an intermediate rate of HCC such as Southern Europe and Japan, hepatitis C is the predominant cause, whereas in low rate areas such as Northern Europe and the USA, HCC is often related to other factors as alcoholic liver disease. There is a rising incidence in HCC in developed countries during the last two decades, due to the increasing rate of hepatitis C infection and improvement of the clinical management of cirrhosis.MethodsThis article reviews the literature on hepatitis and hepatocellular carcinoma. The Medline search was carried out using these key words and articles were selected on epidemiology, risk factors, screening, and prevention of hepatocellular carcinoma.ResultsScreening of patients with advanced chronic hepatitis B and C with hepatic ultrasound and determination of serum alfa-fetoprotein may improve the detection of HCC, but further studies are needed whether screening improves clinical outcome.Hepatitis B and C viruses (HBV/HCV) can be implicated in the development of HCC in an indirect way, through induction of chronic inflammation, or directly by means of viral proteins or, in the case of HBV, by creation of mutations by integration into the genome of the hepatocyte.ConclusionThe most effective tool to prevent HCC is avoidance of the risk factors such as viral infection. For HBV, a very effective vaccine is available. Preliminary data from Taiwan indicate a protective effect of universal vaccination on the development of HCC. Vaccination against HBV should therefore be a health priority. In patients with chronic hepatitis B or C, interferon-alfa treatment in a noncirrhotic stage is protective for HCC development in responders, probably by prevention of cirrhosis development. When cirrhosis is already present, the protective effect is less clear. For cirrhosis due to hepatitis B, a protective effect was demonstrated in Oriental, but not in European patients. For cirrhosis due to hepatitis C, interferon-alfa treatment showed to be protective in some studies, especially in Japan with a high incidence of HCC in untreated patients. Virological, but also merely biochemical response, seems to be associated with a lower risk of development of HCC. As most studies are not randomized controlled trials, no definitive conclusions on the long-term effects of interferon-alfa in HBV or HCV cirrhosis can be established. Especially in hepatitis C, prospective studies should be performed using the more potent reference treatments for cirrhotics, namely the combination of peginterferon and ribavirin.

Transcriptional Activation of Apolipoprotein CIII Expression by Glucose May Contribute to Diabetic Dyslipidemia

Objective—Hypertriglyceridemia and fatty liver are common in patients with type 2 diabetes, but the factors connecting alterations in glucose metabolism with plasma and liver lipid metabolism remain unclear. Apolipoprotein CIII (apoCIII), a regulator of hepatic and plasma triglyceride metabolism, is elevated in type 2 diabetes. In this study, we analyzed whether apoCIII is affected by altered glucose metabolism. Methods and Results—Liver-specific insulin receptor–deficient mice display lower hepatic apoCIII mRNA levels than controls, suggesting that factors other than insulin regulate apoCIII in vivo. Glucose induces apoCIII transcription in primary rat hepatocytes and immortalized human hepatocytes via a mechanism involving the transcription factors carbohydrate response element–binding protein and hepatocyte nuclear factor-4&agr;. ApoCIII induction by glucose is blunted by treatment with agonists of farnesoid X receptor and peroxisome proliferator-activated receptor-&agr; but not liver X receptor, ie, nuclear receptors controlling triglyceride metabolism. Moreover, in obese humans, plasma apoCIII protein correlates more closely with plasma fasting glucose and glucose excursion after oral glucose load than with insulin. Conclusion—Glucose induces apoCIII transcription, which may represent a mechanism linking hyperglycemia, hypertriglyceridemia, and cardiovascular disease in type 2 diabetes.

Prothrombotic factors in histologically proven nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

An independent role of nonalcoholic fatty liver disease (NAFLD) in the development of cardiovascular disease has been suggested, probably mediated through increased levels of prothrombotic factors. Therefore, we examined whether NAFLD is linked to a prothrombotic state, independently of metabolic risk factors in a large single‐center cohort of overweight/obese patients. Patients presenting to the obesity clinic underwent a detailed metabolic and liver assessment, including an extensive panel of coagulation factors. If NAFLD was suspected, a liver biopsy was proposed. A series of 273 consecutive patients (65% female) with a liver biopsy were included (age, 44 ± 0.76 years; body mass index: 39.6 ± 0.40 kg/m2). Increase in fibrinogen, factor VIII, and von Willebrand factor and decrease in antithrombin III correlated with metabolic features, but not with liver histology. Levels of plasminogen activator inhibitor‐1 (PAI‐1) increased significantly with increasing severity of steatosis (P < 0.001), lobular inflammation (P < 0.001), ballooning (P = 0.002), and fibrosis (P < 0.001). Patients with nonalcoholic steatohepatitis had significantly higher PAI‐1 values than those with normal liver (P < 0.001). In multiple regression, including anthropometric and metabolic parameters, steatosis remained an independent predictor of PAI‐1 levels, explaining, together with fasting C‐peptide and waist circumference, 21% of the variance in PAI‐1. No consistent correlations with histology were found for the other coagulation factors. Conclusion: In obesity, NAFLD severity independently contributes to the increase in PAI‐1 levels, whereas other coagulation factors are unaltered. This finding might, in part, explain the increased cardiovascular risk associated with NAFLD. (Hepatology 2014;58:121–129)

Efficacy and safety of simeprevir with PegIFN/ribavirin in naïve or experienced patients infected with chronic HCV genotype 4.

BACKGROUND & AIMS Simeprevir (SMV) is a once-daily (QD), oral hepatitis C virus (HCV) NS3/4A protease inhibitor approved for treatment of genotype (GT) 1 and GT4 infection. This Phase III, open-label, single-arm study (RESTORE; NCT01567735) evaluated efficacy/safety of SMV with peginterferon-α-2a/ribavirin (PR) in patients with chronic HCV GT4 infection. METHODS 107 patients were included. Treatment-naïve (n=35) and prior relapse patients (n=22) received SMV 150mg QD+PR (12 weeks), followed by PR alone (12 or 36 weeks, response-guided [HCV RNA <25IU/ml detectable/undetectable at week 4 and <25IU/ml undetectable at week 12]). Prior non-responders (partial, n=10; null, n=40) received SMV/PR (12 weeks), followed by PR for 36 weeks. The primary endpoint was sustained virologic response 12 weeks after end of treatment (SVR12). RESULTS Median age: 49.0years; 28.0% Black/African; 7.5% IL28B CC; 28.8% METAVIR F4. Overall, 65.4% (70/107) of patients achieved SVR12 (82.9% [29/35] treatment-naïve; 86.4% [19/22] prior relapsers; 60.0% [6/10] prior partial responders; 40.0% [16/40] prior null responders). In treatment-naïve and prior relapser patients fulfilling response-guided criteria for 24 weeks of treatment (88.6% [31/35] and 90.9% [20/22]), SVR12 rates were high: 93.5% [29/31] and 95.0% [19/20], respectively. Overall on-treatment failure and relapse rates were 23.4% (25/107) and 14.6% (12/82), respectively. Adverse events (AEs) were mainly grade 1/2; serious AEs were infrequent (4.7%) and considered unrelated to SMV. CONCLUSIONS Efficacy and safety of SMV 150mg QD for 12 weeks with PR in treatment-naïve or -experienced patients with chronic HCV GT4 infection were in line with previous reports for HCV GT1 infection.

A randomized, placebo‐controlled trial of cenicriviroc for treatment of nonalcoholic steatohepatitis with fibrosis

The aim of this study was to evaluate cenicriviroc (CVC), a dual antagonist of CC chemokine receptor types 2 and 5, for treatment of nonalcoholic steatohepatitis (NASH) with liver fibrosis (LF). A randomized, double‐blind, multinational phase 2b study enrolled subjects with NASH, a nonalcoholic fatty liver disease activity score (NAS) ≥4, and LF (stages 1‐3, NASH Clinical Research Network) at 81 clinical sites. Subjects (N = 289) were randomly assigned CVC 150 mg or placebo. Primary outcome was ≥2‐point improvement in NAS and no worsening of fibrosis at year 1. Key secondary outcomes were: resolution of steatohepatitis (SH) and no worsening of fibrosis; improvement in fibrosis by ≥1 stage and no worsening of SH. Biomarkers of inflammation and adverse events were assessed. Full study recruitment was achieved. The primary endpoint of NAS improvement in the intent‐to‐treat population and resolution of SH was achieved in a similar proportion of subjects on CVC (N = 145) and placebo (N = 144; 16% vs. 19%, P = 0.52 and 8% vs. 6%, P = 0.49, respectively). However, the fibrosis endpoint was met in significantly more subjects on CVC than placebo (20% vs. 10%; P = 0.02). Treatment benefits were greater in those with higher disease activity and fibrosis stage at baseline. Biomarkers of systemic inflammation were reduced with CVC. Safety and tolerability of CVC were comparable to placebo. Conclusion: After 1 year of CVC treatment, twice as many subjects achieved improvement in fibrosis and no worsening of SH compared with placebo. Given the urgent need to develop antifibrotic therapies in NASH, these findings warrant phase 3 evaluation. (Hepatology 2018;67:1754‐1767).

PPARα gene expression correlates with severity and histological treatment response in patients with non-alcoholic steatohepatitis

BACKGROUND & AIMS Peroxisome proliferator-activated receptors (PPARs) have been implicated in non-alcoholic steatohepatitis (NASH) pathogenesis, mainly based on animal data. Gene expression data in NASH patients are scarce. We studied liver PPARα, β/δ, and γ expression in a large cohort of obese patients assessed for presence of NAFLD at baseline and 1 year follow-up. METHODS Patients presented to the obesity clinic underwent a hepatic work-up. If NAFLD was suspected, liver biopsy was performed. Gene expression was studied by mRNA quantification. Patients were reassessed after 1 year. RESULTS 125 patients were consecutively included in the study, of which 85 patients had paired liver biopsy taken at 1 year of follow-up. Liver PPARα expression negatively correlated with the presence of NASH (p=0.001) and with severity of steatosis (p=0.003), ballooning (p=0.001), NASH activity score (p=0.008) and fibrosis (p=0.003). PPARα expression was positively correlated to adiponectin (R(2)=0.345, p=0.010) and inversely correlated to visceral fat (R(2)=-0.343, p<0.001), HOMA IR (R(2)=-0.411, p<0.001) and CK18 (R(2)=-0.233, p=0.012). Liver PPARβ/δ and PPARγ expression did not correlate with any histological feature nor with glucose metabolism or serum lipids. At 1 year, correlation of PPARα expression with liver histology was confirmed. In longitudinal analysis, an increase in expression of PPARα and its target genes was significantly associated with histological improvement (p=0.008). CONCLUSION Human liver PPARα gene expression negatively correlates with NASH severity, visceral adiposity and insulin resistance and positively with adiponectin. Histological improvement is associated with an increase in expression of PPARα and its target genes. These data might suggest that PPARα is a potential therapeutic target in NASH.

Prediction of non-alcoholic fatty-liver disease and liver fat content by serum molecular lipids

Aims/hypothesisWe examined whether analysis of lipids by ultra-performance liquid chromatography (UPLC) coupled to MS allows the development of a laboratory test for non-alcoholic fatty-liver disease (NAFLD), and how a lipid-profile biomarker compares with the prediction of NAFLD and liver-fat content based on routinely available clinical and laboratory data.MethodsWe analysed the concentrations of molecular lipids by UPLC-MS in blood samples of 679 well-characterised individuals in whom liver-fat content was measured using proton magnetic resonance spectroscopy (1H-MRS) or liver biopsy. The participants were divided into biomarker-discovery (n = 287) and validation (n = 392) groups to build and validate the diagnostic models, respectively.ResultsIndividuals with NAFLD had increased triacylglycerols with low carbon number and double-bond content while lysophosphatidylcholines and ether phospholipids were diminished in those with NAFLD. A serum-lipid signature comprising three molecular lipids (‘lipid triplet’) was developed to estimate the percentage of liver fat. It had a sensitivity of 69.1% and specificity of 73.8% when applied for diagnosis of NAFLD in the validation series. The usefulness of the lipid triplet was demonstrated in a weight-loss intervention study.Conclusions/interpretationThe liver-fat-biomarker signature based on molecular lipids may provide a non-invasive tool to diagnose NAFLD, in addition to highlighting lipid molecular pathways involved in the disease.

C-reactive protein levels in relation to various features of non-alcoholic fatty liver disease among obese patients

BACKGROUND & AIMS Non-alcoholic fatty liver disease (NAFLD) is a major hepatic consequence of obesity. It has been suggested that the high sensitivity C-reactive protein (hs-CRP) is an obesity-independent surrogate marker of severity of NAFLD, especially development of non-alcoholic steato-hepatitis (NASH), but this remains controversial. We aimed to investigate whether associations between various features of NAFLD and hs-CRP are independent of body mass index (BMI) in its broad range among obese patients. METHODS A total of 627 obese adults (80% females), representing three cohorts from France and Belgium, had information on liver histology obtained from liver biopsies and measures of hs-CRP and BMI. We investigated whether the different features of NAFLD and BMI were associated with hs-CRP, with and without mutual adjustments using linear regression. RESULTS BMI and hs-CRP were strongly associated. Per every 10% increase in BMI the hs-CRP level increased by 19-20% (p<0.001), and adjustment for NAFLD-stage (including no-NAFLD) did not influence the association. We found no BMI-independent association between NASH and hs-CRP. However, a positive association between degree of steatosis and hs-CRP was observed (p<0.05) and this effect remained significant after adjusting for BMI, lobular inflammation, hepatocyte ballooning, and fibrosis. We found no significant associations between the other features of NAFLD and hs-CRP. CONCLUSIONS This study indicates that it is the accumulation of fat -both in the adipose tissue and in liver steatosis- that leads to increased hs-CRP levels among obese patients. Thus, hs-CRP may be a marker of steatosis, but not of severity of NAFLD, in obese patients.

Non-alcoholic fatty liver disease and cardiovascular risk: Pathophysiological mechanisms and implications

Non-alcoholic fatty liver disease (NAFLD) has become one of the most frequent chronic liver diseases in the Western society and its prevalence is likely to rise even further. An increasing body of evidence shows that NAFLD is not only a potentially progressive liver disease, but also has systemic consequences. More specifically, evidence points out that NAFLD has to be considered as a significant independent risk factor for subclinical and clinical cardiovascular disease (CVD). Long-term follow-up studies demonstrate cardiovascular mortality to be the most important cause of death in NAFLD patients. Moreover, ample evidence associates NAFLD with endothelial dysfunction, increased pulse wave velocity, increased coronary arterial calcifications and increased carotid intima media thickness, all established markers for CVD. Despite of all this evidence, the mechanisms by which NAFLD causally contributes to CVD are not fully elucidated. Furthermore, an extensive overview of all potential pathophysiological mechanisms and the corresponding current data are lacking. In this review we summarise current knowledge, originating from fundamental and clinical research, that mechanistically links NAFLD to CVD. Subsequently, the impact of CVD on current clinical practice and future research in the area of NALFD are discussed.