Association between the PNPLA3 (rs738409 C>G) variant and hepatocellular carcinoma: Evidence from a meta-analysis of individual participant data

PNPLA3 I148 M genetic variant in autoimmune hepatitis characterises advanced disease at diagnosis and reduced survival free of cirrhotic events and liver-related mortality

Background

Autoimmune hepatitis (AIH) is a relatively rare autoimmune disease with a strong genetic background. The patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148 M (rs738409 C/G) variant has been associated with hepatic inflammation and fibrosis in chronic hepatic diseases beyond metabolic dysfunction-associated steatotic liver disease (MASLD).

Aim

Our aim was to investigate the significance of PNPLA3 I148 M variant in AIH.

Method

Two hundred AIH patients, followed in our centre, were evaluated while 100 healthy subjects served as controls. Genotyping was performed with allelic discrimination end-point polymerase chain reaction (PCR).

Results

The I148 M variant was present in 95/200 (47.5 %) AIH patients compared to 47/100 (47 %) healthy controls (p = 1.000). Patients with GG/CG genotypes were more likely to present with decompensated cirrhosis at diagnosis (GG/CG 6.3 % vs. CC 1 %, p = 0.039). Comorbidity with cardiometabolic risk factors and concurrence of MASLD was similar across genotypes. Simple steatosis was present in 37/186 (19.9 %) and steatohepatitis in 14/186 (7.5 %) patients with available liver biopsy without correlation with PNPLA3 genotype. Fibrosis stage and grade of inflammation were not correlated with any genotype. Response to treatment was also independent of the presence of the I148 M variant, even though a longer time was needed to achieve complete biochemical response in those carrying the GG/CG genotypes (p = 0.07). On Kaplan Meier analysis homozygosity for the G allele corelated with reduced survival free of decompensation (p = 0.006), cirrhotic events (decompensation, liver transplantation, hepatocellular carcinoma; p = 0.001) and liver-related death or liver transplantation (p = 0.011) in treated patients.

Conclusions

The PNPLA3 I148 M variant in AIH patients is associated with increased risk of advanced disease at diagnosis and reduced survival free of cirrhotic events and liver-related death or liver transplantation, regardless of the presence of MASLD. This signifies a potential role for the PNPLA3 I148 M variant as a new AIH biomarker allowing to identify patients at increased risk of disease progression.

Global Epidemiological Impact of PNPLA3 I148M on Liver Disease

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) has increased exponentially over the past three decades, in parallel with the global rise in obesity and type 2 diabetes. It is currently the most common cause of liver-related morbidity and mortality. Although obesity has been identified as a key factor in the increased prevalence of MASLD, individual differences in susceptibility are significantly influenced by genetic factors. PNPLA3 I148M (rs738409 C>G) is the variant with the greatest impact on the risk of developing progressive MASLD and likely other forms of steatotic liver disease. This variant is prevalent across the globe, with the risk allele (G) frequency exhibiting considerable variation. Here, we review the contribution of PNPLA3 I148M to global burden and regional differences in MASLD prevalence, focusing on recent evidence emerging from population-based sequencing studies and prevalence assessments. We calculated the population attributable fraction (PAF) as a means of quantifying the impact of the variant on MASLD. Furthermore, we employ quantitative trait locus (QTL) analysis to ascertain the associations between rs738409 and a range of phenotypic traits. This analysis suggests that these QTLs may underpin pleiotropic effects on extrahepatic traits. Finally, we outline potential avenues for further research and identify key areas for investigation in future studies.

Genetic risk accentuates dietary effects on hepatic steatosis, inflammation and fibrosis in a population-based cohort

BACKGROUND & AIMS

Steatotic liver disease (SLD), characterized by elevated liver fat content (LFC), is influenced by genetics and diet. However, whether diet has a differential effect based on genetic risk is not well-characterized. We aimed to determine how genetic factors interact with diet to affect SLD in a large national biobank.

METHODS

We included UK Biobank participants with dietary intake measured by 24-hour recall and genotyping. The primary predictors were dietary pattern, PNPLA3-rs738409-G, TM6SF2-rs58542926-T, a 16-variant hepatic steatosis polygenic risk score (PRS), and gene-environment interactions. The primary outcome was LFC, and secondary outcomes were iron-controlled T1 time (cT1, a measure of liver inflammation and fibrosis) and liver-related events/mortality.

RESULTS

A total of 21,619 participants met inclusion criteria. In non-interaction models, Mediterranean diet and intake of fruit/vegetables/legumes and fish associated with lower LFC, while higher red/processed meat intake and all genetic predictors associated with higher LFC. In interaction models, all genetic predictors interacted with Mediterranean diet and fruit/vegetable/legume intake, while the steatosis PRS interacted with fish intake and the TM6SF2 genotype interacted with red/processed meat intake, to affect LFC. Dietary effects on LFC were up to 3.8-fold higher in PNPLA3-rs738409-GG vs. -CC individuals, and 1.4-3.0-fold higher in the top vs. bottom quartile of the steatosis PRS. Gene-diet interactions were stronger in participants with vs. without overweight. The steatosis PRS interacted with Mediterranean diet and fruit/vegetable/legume intake to affect cT1 and most dietary and genetic predictors associated with risk of liver-related events or mortality by age 70.

CONCLUSIONS

Effects of diet on LFC and cT1 were markedly accentuated in patients at increased genetic risk for SLD, implying dietary interventions may be more impactful in these populations.

IMPACT AND IMPLICATIONS

Genetic variants and diet both influence risk of hepatic steatosis, inflammation/fibrosis, and hepatic decompensation; however, how gene-diet interactions influence these outcomes has previously not been comprehensively characterized. We investigated this topic in the community-based UK Biobank and found that genetic risk and dietary quality interacted to influence hepatic steatosis and inflammation/fibrosis on liver MRI, so that the effects of diet were greater in people at elevated genetic risk. These results are relevant for patients and medical providers because they show that genetic risk is not fixed (i.e. modifiable factors can mitigate or exacerbate this risk) and realistic dietary changes may result in meaningful improvement in liver steatosis and inflammation/fibrosis. As genotyping becomes more routinely used in clinical practice, patients identified to be at high baseline genetic risk may benefit even more from intensive dietary counseling than those at lower risk, though future prospective studies are required.

Integrating genetic and socioeconomic data to predict the progression of nonalcoholic fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease globally, with an estimated prevalence exceeding 25%. Variants in the PNPLA3 and HSD17B13 genes have been a focus of investigations surrounding the etiology and progression of NAFLD and are believed to contribute to a greater burden of disease experienced by Hispanic Americans. However, little is known about socioeconomic factors influencing NAFLD progression or its increased prevalence among Hispanics.

MATERIALS AND METHODS

We cross-sectionally analyzed 264 patients to assess the role of genetic and socioeconomic variables in the development of advanced liver fibrosis in individuals at risk for NAFLD.

RESULTS

Adjusting for age, sex, body mass index, and PNPLA3 genotype, lacking a college degree was associated with 3.3 times higher odds of advanced fibrosis (95% confidence interval [CI]: 1.21-8.76, p = 0.019), an effect comparable to that of possessing the major PNPLA3 risk variant. Notably, the effect of PNPLA3 genotype on advanced fibrosis was attenuated to nonsignificance following adjustment for education and other socioeconomic markers. The effect of the protective HSD17B13 variant, moreover, diminished after adjustment for education (odds ratio [OR]: 0.39 [95% CI: 0.13-1.16, p = 0.092]), while lower education continued to predict advanced fibrosis following multivariable adjustment with an OR of 8.0 (95% CI: 1.91-33.86, p = 0.005).

DISCUSSION

Adjusting for education attenuated the effects of genotype and Hispanic ethnicity on liver fibrosis, suggesting that social factors-rather than genes or ethnicity-may be driving disease severity within some populations. Findings reveal the importance of including socioenvironmental controls when considering the role of genetics or ethnicity in complex disease.

High serum gamma-glutamyltransferase level after hepatitis C virus elimination is a risk factor for the development of hepatocellular carcinoma

AIM

Gamma-glutamyltransferase (GGT) is known as an oxidative stress marker, induced by alcohol consumption and metabolic disorders, and is reported as a predictor of hepatocellular carcinoma (HCC) development after hepatitis C virus (HCV) elimination. However, it is not clear whether GGT serves simply as a surrogate marker for overlapping metabolic diseases or reflects HCV-specific carcinogenicity. We investigated the association between GGT and hepatocarcinogenesis after achieving a sustained viral response (SVR), accounting for drinking habits or diabetes, and examined predisposing factors associated with GGT levels after SVR.

METHODS

This is a prospective, multicenter, and observational study using the database of 1001 patients after HCV eradication with direct-acting antiviral agents. The association of GGT at SVR with cumulative HCC development was examined in a multivariate analysis using Cox proportional hazard models after adjustment for covariates including alcohol and diabetes. The association between oxidative stress markers or genetic factors and GGT levels was analyzed.

RESULTS

High GGT levels at SVR were associated with HCC development (HR] 2.38, 95% CI 1.10-5.17). This association was also significant when restricted to patients without alcohol consumption or diabetes (HR 8.38, 95% CI 2.87-24.47). GGT levels were correlated with serum growth differentiation factor 15 levels, a marker of mitochondrial dysfunction. Single-nucleotide polymorphisms of ZNF827 and GDF15 were associated with high GGT levels.

CONCLUSIONS

High GGT levels at SVR were associated with HCC development after accounting for alcohol consumption and diabetes. GGT levels are influenced by genetic predisposition and may reflect mitochondrial dysfunction after HCV eradication.

Metabolic Syndrome Traits Increase the Risk of Major Adverse Liver Outcomes in Type 2 Diabetes

OBJECTIVE

Type 2 diabetes (T2D) increases the risk for major adverse liver outcomes (MALOs), including cirrhosis and its complications. Patients with T2D frequently have other traits of the metabolic syndrome (MetS). It remains uncertain whether there is a synergistic effect of accumulating MetS traits on future MALO risk.

RESEARCH DESIGN AND METHODS

Patients with T2D without a history of liver disease were identified from national registers in Sweden from 1998 to 2021. MetS traits included hypertension, low HDL level, hypertriglyceridemia, obesity, and albuminuria, in addition to T2D. MALO events were identified based on administrative coding from national registers until 31 October 2022. Data were analyzed using Cox regression models.

RESULTS

In total, 230,992 patients were identified (median age 64 years; 58% male), of whom 3,215 (1.39%) developed MALOs over a median follow-up of 9.9 years. Compared with patients with one MetS trait (only T2D) at baseline, those with more than one MetS trait had a higher rate of MALOs (adjusted hazard ratio [aHR] 2.33, 95% CI 1.53-3.54). The rate of MALOs increased progressively with increasing numbers of MetS traits at baseline (aHR 1.28 per added trait, 95% CI 1.23-1.33). During follow-up, patients who acquired additional MetS traits had a progressively higher rate of MALOs. The MetS trait with the largest association with incident MALOs was hypertension (aHR 2.06, 95% CI 1.57-2.71).

CONCLUSIONS

Having or acquiring additional traits of MetS increase the rate of progression to MALOs in patients with T2D. These results could be used to inform screening initiatives for liver disease.

Population-enriched innate immune variants may identify candidate gene targets at the intersection of cancer and cardio-metabolic disease

Both cancer and cardio-metabolic disease disparities exist among specific populations in the US. For example, African Americans experience the highest rates of breast and prostate cancer mortality and the highest incidence of obesity. Native and Hispanic Americans experience the highest rates of liver cancer mortality. At the same time, Pacific Islanders have the highest death rate attributed to type 2 diabetes (T2D), and Asian Americans experience the highest incidence of non-alcoholic fatty liver disease (NAFLD) and cancers induced by infectious agents. Notably, the pathologic progression of both cancer and cardio-metabolic diseases involves innate immunity and mechanisms of inflammation. Innate immunity in individuals is established through genetic inheritance and external stimuli to respond to environmental threats and stresses such as pathogen exposure. Further, individual genomes contain characteristic genetic markers associated with one or more geographic ancestries (ethnic groups), including protective innate immune genetic programming optimized for survival in their corresponding ancestral environment(s). This perspective explores evidence related to our working hypothesis that genetic variations in innate immune genes, particularly those that are commonly found but unevenly distributed between populations, are associated with disparities between populations in both cancer and cardio-metabolic diseases. Identifying conventional and unconventional innate immune genes that fit this profile may provide critical insights into the underlying mechanisms that connect these two families of complex diseases and offer novel targets for precision-based treatment of cancer and/or cardio-metabolic disease.

Polymorphisms Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease Influence the Progression of End-Stage Liver Disease

BACKGROUND AND AIMS

Chronic liver injury that results in cirrhosis and end-stage liver disease (ESLD) causes more than 1 million deaths annually worldwide. Although the impact of genetic factors on the severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-related liver disease (ALD) has been previously studied, their contribution to the development of ESLD remains largely unexplored.

METHODS

We genotyped 6 MASLD-associated polymorphisms in healthy (n = 123), metabolic dysfunction-associated steatohepatitis (MASH) (n = 145), MASLD-associated ESLD (n = 72), and ALD-associated ESLD (n = 57) cohorts and performed multinomial logistic regression to determine the combined contribution of genetic, demographic, and clinical factors to the progression of ESLD.

RESULTS

Distinct sets of factors are associated with the progression to ESLD. The PNPLA3 rs738409:G and TM6SF2 rs58542926:T alleles, body mass index (BMI), age, and female sex were positively associated with progression from a healthy state to MASH. The PNPLA3 rs738409:G allele, age, male sex, and having type 2 diabetes mellitus were positively associated, while BMI was negatively associated with progression from MASH to MASLD-associated ESLD. The PNPLA3 rs738409:G and GCKR rs780094:T alleles, age, and male sex were positively associated, while BMI was negatively associated with progression from a healthy state to ALD-associated ESLD. The findings indicate that the PNPLA3 rs738409:G allele increases susceptibility to ESLD regardless of etiology, the TM6SF2 rs58542926:T allele increases susceptibility to MASH, and the GCKR rs780094:T allele increases susceptibility to ALD-associated ESLD.

CONCLUSION

The PNPLA3, TM6SF2, and GCKR minor alleles influence the progression of MASLD-associated or ALD-associated ESLD. Genotyping for these variants in MASLD and ALD patients can enhance risk assessment, prompting early interventions to prevent ESLD.

Nonalcoholic Fatty Liver Disease-Related Hepatocellular Carcinoma: The Next Threat after Viral Hepatitis

For many years, we have faced the complications of viral hepatitis and alcohol-related liver diseases such as cirrhosis, decompensation, portal hypertension, and hepatocellular carcinoma (HCC). Recently, we have seen a dynamic change in the field of hepatology. With the significant achievements in eradicating the hepatitis C virus by direct-acting antiviral agents and the rising epidemic of obesity, diabetes mellitus, and metabolic syndrome, there is a paradigm shift in the leading cause of liver cirrhosis and cancer to nonalcoholic fatty liver disease (NAFLD). Current data highlight the rapidly rising incidence of NAFLD-related HCC worldwide and expose the unseen part of the iceberg. In this review, we aim to update knowledge about the pathogenesis of NAFLD-induced HCC, surveillance difficulties, and promising disease markers. Molecular biomarkers, for example, may become a promising cornerstone for risk-stratified surveillance, early detection, and treatment selection for NAFLD-related HCC. Physicians can offer personalized and tailor-made clinical decisions for this unique patient subgroup.

Metabolic liver cancer: associations of rare and common germline variants in one-carbon metabolism and DNA methylation genes

Animal studies implicate one-carbon metabolism and DNA methylation genes in hepatocellular carcinoma (HCC) development in the setting of metabolic perturbations. Using human samples, we investigated the associations between common and rare variants in these closely related biochemical pathways and risk for metabolic HCC development in a multicenter international study. We performed targeted exome sequencing of 64 genes among 556 metabolic HCC cases and 643 cancer-free controls with metabolic conditions. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for multiple comparisons. Gene-burden tests were used for rare variant associations. Analyses were performed in the overall sample and among non-Hispanic whites. The results show that among non-Hispanic whites, presence of rare functional variants in ABCC2 was associated with 7-fold higher risk of metabolic HCC (OR = 6.92, 95% CI: 2.38-20.15, P = 0.0004), and this association remained significant when analyses were restricted to functional rare variants observed in ≥2 participants (cases 3.2% versus controls 0.0%, P = 1.02 × 10-5). In the overall multiethnic sample, presence of rare functional variants in ABCC2 was nominally associated with metabolic HCC (OR = 3.60, 95% CI: 1.52-8.58, P = 0.004), with similar nominal association when analyses were restricted to functional rare variants observed in ≥2 participants (cases 2.9% versus controls 0.2%, P = 0.006). A common variant in PNPLA3 (rs738409[G]) was associated with higher HCC risk in the overall sample (P = 6.36 × 10-6) and in non-Hispanic whites (P = 0.0002). Our findings indicate that rare functional variants in ABCC2 are associated with susceptibility to metabolic HCC in non-Hispanic whites. PNPLA3-rs738409 is also associated with metabolic HCC risk.

Progression to cirrhosis is similar among all ages in nonalcoholic fatty liver disease, but liver-related events increase with age

BACKGROUND

NAFLD is increasingly common among young people. Whether NAFLD carries a more benign course in younger adults is not known. We aimed to characterize genetic and metabolic risk factors for NAFLD and their effects on disease progression across age groups.

METHODS

We conducted a retrospective study of adults with NAFLD seen within Michigan Medicine, a tertiary care center, between 2010 and 2021. NAFLD was defined by hepatic steatosis on imaging, biopsy, or transient elastography in the absence of other chronic liver diseases. Cirrhosis was determined by validated International Classification of Diseases-9/10 codes or imaging. Fine-Gray competing risk models were generated, with incident cirrhosis and liver-related events (LREs) as the primary outcomes and death without cirrhosis or LREs as a competing risk. The primary predictor was the age category.

RESULTS

We included 31,505 patients with NAFLD, with 8,252 aged 18 to younger than 40, 15,035 aged 40 to younger than 60, and 8,218 aged 60 years or older years at diagnosis. Compared with older patients, young adults more often had obesity, higher ALT, and high-risk PNPLA3 alleles, and fewer had prevalent cirrhosis, hypertension, hyperlipidemia, and diabetes. The 10-year risk of incident cirrhosis was similar between ages (3.4% in age 18 to <40 vs 3.7% in age 40 to <60 vs 4.7% in age ≥60; p = 0.058). Predictors of LREs were advancing age and diabetes, with a significantly higher 10-year risk of LREs in the oldest age group (0.2% in age 18 to <40 vs 0.7% in age 40 to <60 vs 1.1% in age ≥60; p = 0.008).

CONCLUSIONS

While the baseline prevalence of cirrhosis was higher among older adults, the rate of NAFLD progression to cirrhosis was similar in young and older adults. Older patients were more likely to have LREs.

Risk stratification for hepatocellular cancer among patients with cirrhosis using a hepatic fat polygenic risk score

BACKGROUND

Polygenic risk scores (PRS) hold the promise to refine prognostication in hepatocellular cancer (HCC). The few available HCC PRS include germline risk variants identified among individuals of mostly European ancestry, but data are lacking on the transportability of these PRS in multiethnic U.S patients with cirrhosis from multiple etiologies.

METHODS

We used data from 1644 patients with cirrhosis enrolled in two prospective cohort studies in the U.S. Patients were followed until HCC diagnosis, death, liver transplantation, or last study visit through June 30, 2021. The high-risk variants in PNPLA3-MBOAT7-TM6SF2-GCKR were combined in a PRS and we evaluated its association with HCC. Discriminatory accuracy was assessed using the C-statistic.

RESULTS

During 4,759 person-years of follow-up, 93 patients developed HCC. Mean age was 59.8 years, 68.6% were male, 27.2% Hispanic, 25.1% non-Hispanic Black, 25.7% had NAFLD, 42.1% had heavy alcohol use, and 19.5% had active HCV. HCC risk increased by 134% per unit increase in PRS (HR = 2.30; 95% CI, 1.35-3.92). Compared to cirrhosis patients in the lowest tertile of the PRS, those in the highest tertile had 2-fold higher risk of HCC (HR = 2.05; 95% CI, 1.22-3.44). The PRS alone had modest discriminatory ability (C-statistic = 0.58; 95% CI, 0.52-0.63); however, adding PRS to a predictive model with traditional HCC risk factors had a C-statistic of 0.70 (95% CI, 0.64-0.76), increasing from 0.68 without the PRS (p = 0.0012).

CONCLUSIONS

Our findings suggest that PRS may enhance risk prediction for HCC in contemporary U.S. cirrhosis patients.

Genetics of Hepatocellular Carcinoma: From Tumor to Circulating DNA

Hepatocellular carcinoma (HCC) accounts for 90% of primary hepatic malignancies and is one of the major causes of cancer-related death. Over the last 15 years, the molecular landscape of HCC has been deciphered, with the identification of the main driver genes of liver carcinogenesis that belong to six major biological pathways, such as telomere maintenance, Wnt/b-catenin, P53/cell cycle regulation, oxidative stress, epigenetic modifiers, AKT/mTOR and MAP kinase. The combination of genetic and transcriptomic data composed various HCC subclasses strongly related to risk factors, pathological features and prognosis. However, translation into clinical practice is not achieved, mainly because the most frequently mutated genes are undruggable. Moreover, the results derived from the analysis of a single tissue sample may not adequately catch the intra- and intertumor heterogeneity. The analysis of circulating tumor DNA (ctDNA) is broadly developed in other types of cancer for early diagnosis, prognosis and monitoring under systemic treatment in order to identify primary and secondary mechanisms of resistance. The aim of this review is to describe recent data about the HCC molecular landscape and to discuss how ctDNA could be used in the future for HCC detection and management.

Low Frequency of Cancer-Predisposition Gene Mutations in Liver Transplant Candidates with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) mainly stems from liver cirrhosis and its genetic predisposition is believed to be rare. However, two recent studies describe pathogenic/likely pathogenic germline variants (PV) in cancer-predisposition genes (CPG). As the risk of de novo tumors might be increased in PV carriers, especially in immunosuppressed patients after a liver transplantation, we analyzed the prevalence of germline CPG variants in HCC patients considered for liver transplantation. Using the panel NGS targeting 226 CPGs, we analyzed germline DNA from 334 Czech HCC patients and 1662 population-matched controls. We identified 48 PVs in 35 genes in 47/334 patients (14.1%). However, only 7/334 (2.1%) patients carried a PV in an established CPG (PMS2, 4×NBN, FH or RET). Only the PV carriers in two MRN complex genes (NBN and RAD50) were significantly more frequent among patients over controls. We found no differences in clinicopathological characteristics between carriers and non-carriers. Our study indicated that the genetic component of HCC is rare. The HCC diagnosis itself does not meet criteria for routine germline CPG genetic testing. However, a low proportion of PV carriers may benefit from a tailored follow-up or targeted therapy and germline testing could be considered in liver transplant recipients.

PNPLA3 allele frequency has no impact on biliary bile acid composition or disease course in patients with primary sclerosing cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease that leads to bile duct strictures, cholestasis, and biliary cirrhosis. PNPLA3 (patatin-like phospholipase domain containing 3), regulates cellular lipid synthesis by converting lysophosphatidic acid into phosphatidic acid. Isoleucine mutation to methionine at position 148 (I148M) causes a loss of this function. Only two studies, with contradictory results, have evaluated the role of PNPLA3 in PSC. The rs738409(G) variant of PNPLA3 has been associated with an increased risk for transplantation in male patients with dominant strictures (DS). The study aimed to evaluate the PNPLA3 allele frequency effect on the clinical outcomes, progression, and prognosis of PSC. Furthermore, we analyzed the impact of PNPLA3 on phospholipid and bile acid composition to evaluate the effect of the PNPLA3 status on UDCA response.

PATIENTS AND METHODS

We recruited 560 patients prospectively and collected clinical and laboratory data as well as liver histology and imaging findings. PNPLA3 (CC, CG, GG) alleles were analyzed with TaqManTM. We also analyzed bile acids (BA), cholesterol and phospholipids and individual BA from a sample aspirated during endoscopic retrograde cholangiography (ERC).

RESULTS

Among the recruited patients, 58.4%, 35.7% and 5.9% had the wild (CC), heterozygous (CG) and homozygous (GG) alleles, respectively. The PNPLA3 haplotype did not impact bile composition or individual BA. In addition, we found no differences in age at diagnosis, disease progression, liver fibrosis or survival between the cohorts.

CONCLUSIONS

The PNPLA3 I148M variant had no significant impact on on bile composition, including UDCA content, clinical outcomes, progression of liver fibrosis, hepatobiliary cancer risk, liver transplantation, or overall survival.

miR-516a-3P, a potential circulating biomarker in hepatocellular carcinoma, correlated with rs738409 polymorphism in PNPLA3

Aim: The aim was to investigate the expression profile of miR-516a-3P and its correlation with the PNPLA3 rs738409 polymorphism in Egyptian hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) patients. Materials & methods: miR-516a-3P was quantified and rs738409 was genotyped by quantitative reverse transcription PCR. Results: miR-516a-3P was significantly upregulated in HCC patients compared with HCV patients (p = 0.001). Receiver operating characteristic curve analysis confirmed that miR-516a-3P discriminates HCC from HCV (p = 0.001). A significant (p = 0.015) correlation between miR-516a-3p level and PNPLA3 rs738409 genotypes was recorded in HCV patients, yet it was not recorded in either healthy individuals or HCC patients. miR-516a-3p level was significantly (p = 0.001) higher in HCV patients carrying the rs738409 GG genotype than in those carrying the CC genotype. Conclusion: miR-516a-3P is a potential biomarker in HCC. PNPLA3 rs738409 GG carriers affect miR-516a-3P expression in HCV, and this may highlight a new mechanism in liver disease.

The impact of polymorphism in PNPLA3 and TM6SF2 genes on the susceptibility and survival of hepatitis C-related hepatocellular carcinoma

Background

Genetic variants of Patatin-like phospholipase domain-containing protein 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) genes have been reported with the development of hepatocellular carcinoma (HCC). This study aims to explore the role of The PNPLA3 rs738409 and TM6SF2 rs58542926 single-nucleotide polymorphisms (SNPs) on the incidence and survival of HCV-induced HCC in Egyptians.

Methods and results

This case-control study included (120) HCC and (144) hepatitis C virus (HCV) patients. Baseline clinical, laboratory, tumor characteristics data, HCC recurrence, and overall survival were collected. PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphism were detected by TaqMan allelic discrimination assay. We found that HCC patients were significantly older with male predominance. A significant difference between the TT genotypes of TM6SF2 frequency was observed in HCC compared with HCV patients. Moreover, the T allele of TM6SF2 distributions revealed a significant contribution to the different stages of HCC (p=0.03). Both PNPLA3 rs738409 and TM6SF2 rs58542926 variants showed a significant relation with treatment response according to the modified RECIST criteria. Age and diabetes mellitus were the independent factors associated with the development of HCC by multivariate regression analysis.

Conclusions

TM6SF2 rs58542926 polymorphism, not PNPLA3 rs738409, could be implicated in the development of HCV-induced HCC and its progression.

Non-Alcoholic Fatty Liver Disease and Extrahepatic Cancers: A Wolf in Sheep’s Clothing?

Non-alcoholic fatty liver disease (NAFLD) is now considered the main driver and leading cause of chronic liver disease globally. The umbrella term NAFLD describes a range of liver conditions closely related to insulin resistance, metabolic syndrome, diabetes mellitus, obesity, and dyslipidemia. At the same time, several malignancies, including hepatocellular carcinoma and colorectal cancer, are considered to be common causes of death among patients with NAFLD. At first, our review herein aims to investigate the role of NAFLD in developing colorectal neoplasms and adenomatous polyps based on the current literature. We will also explore the connection and the missing links between NAFLD and extrahepatic cancers. Interestingly, any relationship between NAFLD and extrahepatic malignancies could be attributable to several shared metabolic risk factors. Overall, obesity, insulin resistance, metabolic syndrome, and related disorders may increase the risk of developing cancer. Therefore, early diagnosis of NAFLD is essential for preventing the progression of the disease and avoiding its severe complications. In addition, cancer screening and early detection in these patients may improve survival and reduce any delays in treatment.

The Role of Chronic Liver Diseases in the Emergence and Recurrence of Hepatocellular Carcinoma: An Omics Perspective

Hepatocellular carcinoma (HCC) typically develops from a background of cirrhosis resulting from chronic inflammation. This inflammation is frequently associated with chronic liver diseases (CLD). The advent of next generation sequencing has enabled extensive analyses of molecular aberrations in HCC. However, less attention has been directed to the chronically inflamed background of the liver, prior to HCC emergence and during recurrence following surgery. Hepatocytes within chronically inflamed liver tissues present highly activated inflammatory signaling pathways and accumulation of a complex mutational landscape. In this altered environment, cells may transform in a stepwise manner toward tumorigenesis. Similarly, the chronically inflamed environment which persists after resection may impact the timing of HCC recurrence. Advances in research are allowing an extensive epigenomic, transcriptomic and proteomic characterization of CLD which define the emergence of HCC or its recurrence. The amount of data generated will enable the understanding of oncogenic mechanisms in HCC from the CLD perspective and provide the possibility to identify robust biomarkers or novel therapeutic targets for the treatment of primary and recurrent HCC. Importantly, biomarkers defined by the analysis of CLD tissue may permit the early detection or prevention of HCC emergence and recurrence. In this review, we compile the current omics based evidence of the contribution of CLD tissues to the emergence and recurrence of HCC.

Improvement of liver fibrosis, but not steatosis, after HCV eradication as assessment by MR-based imaging: Role of metabolic derangement and host genetic variants

Significant liver fibrosis regression occurs after hepatitis C virus (HCV) therapy. However, the impact of direct-acting antivirals (DAAs) on steatosis is less clear. This study was aimed at evaluating serial fibrosis and steatosis alterations in patients with HCV genotype 1, who achieved sustained virological response (SVR). We enrolled 55 HCV mono-infected and 28 HCV/HIV co-infected patients receiving elbasvir/grazoprevir from a clinical trial. Fibrosis and steatosis were assessed at baseline, follow-up week-24 (FUw24) and week-72 (FUw72) by magnetic resonance elastography (MRE) and proton density fat fraction (PDFF), respectively. Patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409, transmembrane six superfamily member 2 (TM6SF2) rs58542926 and membrane bound O-acyltransferase domain-containing 7 (MBOAT7) rs641738 polymorphisms were determined by allelic discrimination. Overall, mean MRE decreased significantly from baseline to FUw24 and FUw72. At FUw72, patients with baseline F2-F4 had higher rate of ≥30% MRE decline compared with individuals with baseline F0-F1 (30.2%vs.3.3%, P = 0.004). In multivariate analysis, significant fibrosis was associated with MRE reduction. The prevalence of steatosis (PDFF≥5.2%) at baseline was 21.7%. Compared to baseline, there were 17 (20.5%) patients with decreased PDFF values at FUw72 (<30%), while 23 (27.7%) patients had increased PDFF values (≥30%). Regarding the overall cohort, mean PDFF significantly increased from baseline to FUw72, and displayed positive correlation with body mass index (BMI) alteration. In multivariate analysis, the presence of diabetes, PNPLA3 CG+GG genotypes and increased BMI at FUw72 were significantly associated with progressive steatosis after SVR. Other genetic variants were not related to fibrosis and steatosis alteration. This study concluded that HCV eradication was associated with fibrosis improvement. However, progressive steatosis was observed in a proportion of patients, particularly among individuals with metabolic derangement and PNPLA3 variants. The combined clinical parameters and host genetic factors might allow a better individualized strategy in this sub-group of patients to alleviate progressive steatosis after HCV cure.

The Pnpla3 Variant I148M Reveals Protective Effects Towards Hepatocellular Carcinoma in Mice via Restoration of Omega-3 Polyunsaturated Fats

Alcohol consumption and high caloric diet are leading causes of progressive fatty liver disease. Genetic variant rs738409 in patatin-like phospholipase domain-containing protein 3 (PNPLA3 rs738409 C>G) has been repeatedly described as one of the major risk loci for alcoholic liver cirrhosis (ALC) and hepatocellular carcinoma (HCC) in humans, however, the mechanism behind this association is incompletely understood. We generated mice carrying the rs738409 variant (PNPLA3 I148M) in order to detect genotype-phenotype relationships in mice upon chow and alcohol-high fat/high sugar diet (EtOH/WD). We could clearly demonstrate that the presence of rs738409 per se is sufficient to induce spontaneous development of steatosis after one year in mice on a chow diet, whereas in the setting of unhealthy diet feeding, PNPLA3 I148M did not affect hepatic inflammation or fibrosis, but induced a striking lipid remodelling, microvesicular steatosis and protected from HCC formation. Using shot gun lipidomics, we detected a striking restoration of reduced long chain-polyunsaturated fatty acids (LC-PUFA)-containing TGs, docosapentaenoic acid (C22:5 n3) and omega-3-derived eicosanoids (5-HEPE, 20-HEPE, 19,20-EDP, 21-HDHA) in PNPLA3 I148M mice upon EtOH/WD. At the molecular level, PNPLA3 I148M modulated enzymes for fatty acid and TG transport and metabolism. These findings suggest (dietary) lipids as an important and independent driver of hepatic tumorigenesis. Genetic variant in PNPLA3 exerted protective effects in mice, conflicting with findings in humans. Species-related differences in physiology and metabolism should be taken into account when modelling unhealthy human lifestyle, as genetic mouse models may not always allow for translation of insight gained in humans.

Hepatocellular Carcinoma Due to Nonalcoholic Fatty Liver Disease: Current Concepts and Future Challenges

Obesity has been labeled as the global pandemic of the 21st century, resulting from a sedentary lifestyle and caloric excess. Nonalcoholic fatty liver disease (NAFLD), characterized by excessive hepatic steatosis, is strongly associated with obesity and metabolic syndrome and is estimated to be present in one-quarter of the world population, making it the most common cause of the chronic liver disease (CLD). NAFLD spectrum varies from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. The burden of NAFLD has been predicted to increase in the coming decades resulting in increased rates of decompensated cirrhosis, hepatocellular carcinoma (HCC), and liver-related deaths. In the current review, we describe the pathophysiology of NAFLD and NASH, risk factors associated with disease progression, related complications, and mortality. Later, we have discussed the changing epidemiology of HCC, with NAFLD emerging as the most common cause of CLD and HCC. We have also addressed the risk factors of HCC development in the NAFLD population (including demographic, metabolic, genetic, dietary, and lifestyle factors), presentation of NAFLD-associated HCC, its prognosis, and the issue of HCC development in non-cirrhotic NAFLD. Lastly, the problems related to HCC screening in the NAFLD population, the remaining challenges, and future directions, especially the need to identify the high-risk individuals, will be discussed. We will conclude the review by summarizing the clinical evidence for treating fibrosis and preventing HCC in those at risk with NAFLD-associated HCC.

A genetic risk score and diabetes predict development of alcohol-related cirrhosis in drinkers

BACKGROUND & AIMS

Only a minority of excess alcohol drinkers develop cirrhosis. We developed and evaluated risk stratification scores to identify those at highest risk.

METHODS

Three cohorts (GenomALC-1: n = 1,690, GenomALC-2: n = 3,037, UK Biobank: relevant n = 6,898) with a history of heavy alcohol consumption (≥80 g/day (men), ≥50 g/day (women), for ≥10 years) were included. Cases were participants with alcohol-related cirrhosis. Controls had a history of similar alcohol consumption but no evidence of liver disease. Risk scores were computed from up to 8 genetic loci identified previously as associated with alcohol-related cirrhosis and 3 clinical risk factors. Score performance for the stratification of alcohol-related cirrhosis risk was assessed and compared across the alcohol-related liver disease spectrum, including hepatocellular carcinoma (HCC).

RESULTS

A combination of 3 single nucleotide polymorphisms (SNPs) (PNPLA3:rs738409, SUGP1-TM6SF2:rs10401969, HSD17B13:rs6834314) and diabetes status best discriminated cirrhosis risk. The odds ratios (ORs) and (95% CIs) between the lowest (Q1) and highest (Q5) score quintiles of the 3-SNP score, based on independent allelic effect size estimates, were 5.99 (4.18-8.60) (GenomALC-1), 2.81 (2.03-3.89) (GenomALC-2), and 3.10 (2.32-4.14) (UK Biobank). Patients with diabetes and high risk scores had ORs of 14.7 (7.69-28.1) (GenomALC-1) and 17.1 (11.3-25.7) (UK Biobank) compared to those without diabetes and with low risk scores. Patients with cirrhosis and HCC had significantly higher mean risk scores than patients with cirrhosis alone (0.76 ± 0.06 vs. 0.61 ± 0.02, p = 0.007). Score performance was not significantly enhanced by information on additional genetic risk variants, body mass index or coffee consumption.

CONCLUSIONS

A risk score based on 3 genetic risk variants and diabetes status enables the stratification of heavy drinkers based on their risk of cirrhosis, allowing for the provision of earlier preventative interventions.

LAY SUMMARY

Excessive chronic drinking leads to cirrhosis in some people, but so far there is no way to identify those at high risk of developing this debilitating disease. We developed a genetic risk score that can identify patients at high risk. The risk of cirrhosis is increased >10-fold with just two risk factors - diabetes and a high genetic risk score. Risk assessment using this test could enable the early and personalised management of this disease in high-risk patients.

HSD17B13 and other liver fat-modulating genes predict development of hepatocellular carcinoma among HCV-positive cirrhotics with and without viral clearance after DAA treatment

BACKGROUND

Genetic predisposition to accumulate liver fat (expressed by a polygenic risk score, GRS, based on the number of at-risk alleles of PNPLA3, TM6SF2, MBOAT7 and GCKR) may influence the probability of developing hepatocellular carcinoma (HCC) after hepatitis C treatment. Whether this holds true taking into account carriage of the HSD17B13:TA splice variant, also affecting lipogenesis, and achievement of viral clearance (SVR), is unknown.

METHODS

PNPLA3, TM6SF2, MBOAT7, GCKR and HSD17B13 variants were determined in a cohort of 328 cirrhotic patients free of HCC before starting treatment with direct acting antivirals (DAA).

RESULTS

SVR in the study cohort was 96%. At the end of follow-up, N = 21 patients had been diagnosed an HCC; none of the genes included in the GRS was individually associated with HCC development. However, in a Cox proportional hazards model, a GRS > 0.457 predicted HCC independently of sex, diabetes, albumin, INR and FIB4. The fit of the model improved adding treatment outcome and carriage of the HSD17B13:TA splice variant, with sex, GRS > 0.457, HSD17B13:TA splice variant and failure to achieve an SVR (hazard ratio = 6.75, 4.24, 0.24 and 7.7, respectively) being independent predictors of HCC.

CONCLUSION

Our findings confirm that genes modulating liver fat and lipogenesis are important risk factors for HCC development among cirrhotics C treated with DAA.

Liver specific, systemic and genetic contributors to alcohol-related liver disease progression

Alcohol-related liver disease (ALD) impacts millions of patients worldwide each year and the numbers are increasing. Disease stages range from steatosis via steatohepatitis and fibrosis to cirrhosis, severe alcohol-associated hepatitis and liver cancer. ALD is usually diagnosed at an advanced stage of progression with no effective therapies. A major research goal is to improve diagnosis, prognosis and also treatments for early ALD. This however needs prioritization of this disease for financial investment in basic and clinical research to more deeply investigate mechanisms and identify biomarkers and therapeutic targets for early detection and intervention. Topics of interest are communication of the liver with other organs of the body, especially the gut microbiome, the individual genetic constitution, systemic and liver innate inflammation, including bacterial infections, as well as fate and number of hepatic stellate cells and the composition of the extracellular matrix in the liver. Additionally, mechanical forces and damaging stresses towards the sophisticated vessel system of the liver, including the especially equipped sinusoidal endothelium and the biliary tract, work together to mediate hepatocytic import and export of nutritional and toxic substances, adapting to chronic liver disease by morphological and functional changes. All the aforementioned parameters contribute to the outcome of alcohol use disorder and the risk to develop advanced disease stages including cirrhosis, severe alcoholic hepatitis and liver cancer. In the present collection, we summarize current knowledge on these alcohol-related liver disease parameters, excluding the aspect of inflammation, which is presented in the accompanying review article by Lotersztajn and colleagues.

Understanding the Role of the Gut Microbiome and Microbial Metabolites in Non-Alcoholic Fatty Liver Disease: Current Evidence and Perspectives

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. NAFLD begins as a relatively benign hepatic steatosis which can evolve to non-alcoholic steatohepatitis (NASH); the risk of cirrhosis and hepatocellular carcinoma (HCC) increases when fibrosis is present. NAFLD represents a complex process implicating numerous factors—genetic, metabolic, and dietary—intertwined in a multi-hit etiopathogenetic model. Recent data have highlighted the role of gut dysbiosis, which may render the bowel more permeable, leading to increased free fatty acid absorption, bacterial migration, and a parallel release of toxic bacterial products, lipopolysaccharide (LPS), and proinflammatory cytokines that initiate and sustain inflammation. Although gut dysbiosis is present in each disease stage, there is currently no single microbial signature to distinguish or predict which patients will evolve from NAFLD to NASH and HCC. Using 16S rRNA sequencing, the majority of patients with NAFLD/NASH exhibit increased numbers of Bacteroidetes and differences in the presence of Firmicutes, resulting in a decreased F/B ratio in most studies. They also present an increased proportion of species belonging to Clostridium, Anaerobacter, Streptococcus, Escherichia, and Lactobacillus, whereas Oscillibacter, Flavonifaractor, Odoribacter, and Alistipes spp. are less prominent. In comparison to healthy controls, patients with NASH show a higher abundance of Proteobacteria, Enterobacteriaceae, and Escherichia spp., while Faecalibacterium prausnitzii and Akkermansia muciniphila are diminished. Children with NAFLD/NASH have a decreased proportion of Oscillospira spp. accompanied by an elevated proportion of Dorea, Blautia, Prevotella copri, and Ruminococcus spp. Gut microbiota composition may vary between population groups and different stages of NAFLD, making any conclusive or causative claims about gut microbiota profiles in NAFLD patients challenging. Moreover, various metabolites may be involved in the pathogenesis of NAFLD, such as short-chain fatty acids, lipopolysaccharide, bile acids, choline and trimethylamine-N-oxide, and ammonia. In this review, we summarize the role of the gut microbiome and metabolites in NAFLD pathogenesis, and we discuss potential preventive and therapeutic interventions related to the gut microbiome, such as the administration of probiotics, prebiotics, synbiotics, antibiotics, and bacteriophages, as well as the contribution of bariatric surgery and fecal microbiota transplantation in the therapeutic armamentarium against NAFLD. Larger and longer-term prospective studies, including well-defined cohorts as well as a multi-omics approach, are required to better identify the associations between the gut microbiome, microbial metabolites, and NAFLD occurrence and progression.

Common genetic variation in alcohol-related hepatocellular carcinoma: a case-control genome-wide association study

BACKGROUND

Hepatocellular carcinoma is a frequent consequence of alcohol-related liver disease, with variable incidence among heavy drinkers. We did a genome-wide association study (GWAS) to identify common genetic variants for alcohol-related hepatocellular carcinoma.

METHODS

We conducted a two-stage case-control GWAS in a discovery cohort of 2107 unrelated European patients with alcohol-related liver disease aged 20-92 years recruited between Oct 22, 1993, and March 12, 2017. Cases were patients with alcohol-related hepatocellular carcinoma diagnosed by imaging or histology. Controls were patients with alcohol-related liver disease without hepatocellular carcinoma. We used an additive logistic regression model adjusted for the first ten principal components to assess genetic variants associated with alcohol-related hepatocellular carcinoma. We did another analysis with adjustment for age, sex, and liver fibrosis. New candidate associations (p<1 × 10^-6) and variants previously associated with alcohol-related hepatocellular carcinoma were evaluated in a validation cohort of 1933 patients with alcohol-related liver disease aged 29-92 years recruited between July 21, 1995, and May 2, 2019. We did a meta-analysis of the two case-control cohorts.

FINDINGS

The discovery cohort included 775 cases and 1332 controls. Of 7 962 325 variants assessed, we identified WNT3A-WNT9A (rs708113; p=1·11 × 10^-8) and found support for previously reported regions associated with alcohol-related hepatocellular carcinoma risk at TM6SF2 (rs58542926; p=6·02 × 10^-10), PNPLA3 (rs738409; p=9·29 × 10^-7), and HSD17B13 (rs72613567; p=2·49 × 10^-4). The validation cohort included 874 cases and 1059 controls and three variants were replicated: WNT3A-WNT9A (rs708113; p=1·17 × 10^-3), TM6SF2 (rs58542926; p=4·06 × 10^-5), and PNPLA3 (rs738409; p=1·17 × 10^-4). All three variants reached GWAS significance in the meta-analysis: WNT3A-WNT9A (odds ratio 0·73, 95% CI 0·66-0·81; p=3·93 × 10^-10), TM6SF2 (1·77, 1·52-2·07; p=3·84×10^-13), PNPLA3 (1·34, 1·22-1·47; p=7·30 × 10^-10). Adjustment for clinical covariates yielded similar results. We observed an additive effect of at-risk alleles on alcohol-related hepatocellular carcinoma. WNT3A-WNT9A rs708113 was not associated with liver fibrosis.

INTERPRETATION

WNT3A-WNT9A is a susceptibility locus for alcohol-related hepatocellular carcinoma, suggesting an early role of the Wnt-β-catenin pathway in alcohol-related hepatocellular carcinoma carcinogenesis.

FUNDING

Ligue Nationale contre le Cancer, Bpifrance, INSERM, AFEF, CARPEM, Labex OncoImmunology, and Agence Nationale de la Recherche.

Genetics, Immunity and Nutrition Boost the Switching from NASH to HCC

Nonalcoholic fatty liver disease (NAFLD) is the leading contributor to the global burden of chronic liver diseases. The phenotypic umbrella of NAFLD spans from simple and reversible steatosis to nonalcoholic steatohepatitis (NASH), which may worsen into cirrhosis and hepatocellular carcinoma (HCC). Notwithstanding, HCC may develop also in the absence of advanced fibrosis, causing a delayed time in diagnosis as a consequence of the lack of HCC screening in these patients. The precise event cascade that may precipitate NASH into HCC is intricate and it entails diverse triggers, encompassing exaggerated immune response, endoplasmic reticulum (ER) and oxidative stress, organelle derangement and DNA aberrancies. All these events may be accelerated by both genetic and environmental factors. On one side, common and rare inherited variations that affect hepatic lipid remodeling, immune microenvironment and cell survival may boost the switching from steatohepatitis to liver cancer, on the other, diet-induced dysbiosis as well as nutritional and behavioral habits may furtherly precipitate tumor onset. Therefore, dietary and lifestyle interventions aimed to restore patients' health contribute to counteract NASH progression towards HCC. Even more, the combination of therapeutic strategies with dietary advice may maximize benefits, with the pursuit to improve liver function and prolong survival.

Molecular characterisation of hepatocellular carcinoma in patients with non-alcoholic steatohepatitis

BACKGROUND AND AIMS

Non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) is increasing globally, but its molecular features are not well defined. We aimed to identify unique molecular traits characterising NASH-HCC compared to other HCC aetiologies.

METHODS

We collected 80 NASH-HCC and 125 NASH samples from 5 institutions. Expression array (n = 53 NASH-HCC; n = 74 NASH) and whole exome sequencing (n = 52 NASH-HCC) data were compared to HCCs of other aetiologies (n = 184). Three NASH-HCC mouse models were analysed by RNA-seq/expression-array (n = 20). Activin A receptor type 2A (ACVR2A) was silenced in HCC cells and proliferation assessed by colorimetric and colony formation assays.

RESULTS

Mutational profiling of NASH-HCC tumours revealed TERT promoter (56%), CTNNB1 (28%), TP53 (18%) and ACVR2A (10%) as the most frequently mutated genes. ACVR2A mutation rates were higher in NASH-HCC than in other HCC aetiologies (10% vs. 3%, p <0.05). In vitro, ACVR2A silencing prompted a significant increase in cell proliferation in HCC cells. We identified a novel mutational signature (MutSig-NASH-HCC) significantly associated with NASH-HCC (16% vs. 2% in viral/alcohol-HCC, p = 0.03). Tumour mutational burden was higher in non-cirrhotic than in cirrhotic NASH-HCCs (1.45 vs. 0.94 mutations/megabase; p <0.0017). Compared to other aetiologies of HCC, NASH-HCCs were enriched in bile and fatty acid signalling, oxidative stress and inflammation, and presented a higher fraction of Wnt/TGF-β proliferation subclass tumours (42% vs. 26%, p = 0.01) and a lower prevalence of the CTNNB1 subclass. Compared to other aetiologies, NASH-HCC showed a significantly higher prevalence of an immunosuppressive cancer field. In 3 murine models of NASH-HCC, key features of human NASH-HCC were preserved.

CONCLUSIONS

NASH-HCCs display unique molecular features including higher rates of ACVR2A mutations and the presence of a newly identified mutational signature.

LAY SUMMARY

The prevalence of hepatocellular carcinoma (HCC) associated with non-alcoholic steatohepatitis (NASH) is increasing globally, but its molecular traits are not well characterised. In this study, we uncovered higher rates of ACVR2A mutations (10%) - a potential tumour suppressor - and the presence of a novel mutational signature that characterises NASH-related HCC.

Genetics Is of the Essence to Face NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease worldwide. It is closely related to obesity, insulin resistance (IR) and dyslipidemia so much so it is considered the hepatic manifestation of the Metabolic Syndrome. The NAFLD spectrum extends from simple steatosis to nonalcoholic steatohepatitis (NASH), a clinical condition which may progress up to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). NAFLD is a complex disease whose pathogenesis is shaped by both environmental and genetic factors. In the last two decades, several heritable modifications in genes influencing hepatic lipid remodeling, and mitochondrial oxidative status have been emerged as predictors of progressive hepatic damage. Among them, the patatin-like phospholipase domain-containing 3 (PNPLA3) p.I148M, the Transmembrane 6 superfamily member 2 (TM6SF2) p.E167K and the rs641738 membrane bound-o-acyltransferase domain-containing 7 (MBOAT7) polymorphisms are considered the most robust modifiers of NAFLD. However, a forefront frontier in the study of NAFLD heritability is to postulate score-based strategy, building polygenic risk scores (PRS), which aggregate the most relevant genetic determinants of NAFLD and biochemical parameters, with the purpose to foresee patients with greater risk of severe NAFLD, guaranteeing the most highly predictive value, the best diagnostic accuracy and the more precise individualized therapy.

Genetic risk scores and personalization of care in fatty liver disease

Nonalcoholic fatty liver disease is the leading cause of chronic liver disease. Genetic predisposition, lifestyle, and metabolic comorbidities concur to nonalcoholic fatty liver disease development and progression to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. Improvement in risk stratification and development of effective therapies for nonalcoholic steatohepatitis are key unmet clinical needs. Knowledge emerging from genomics could meet this need. A polygenic risk score (PRS) is calculated by summing the number of trait-associated alleles carried by an individual, which can be weighted by their effect size on the trait and captures the individual's genetic risk to develop a disease. In this review, we focalize on the potential use of PRSs for disease detection at an early stage and stratification of the risk of progression to severe forms. PRSs may represent robust instruments to implement targeted prevention programs, hepatocellular carcinoma surveillance in at-risk individuals, and to develop precision medicine therapeutic approaches.

Genetic and Environmental Susceptibility to Alcoholic Hepatitis

Constitutional, environmental, and genetic risk factors influence the development of alcohol-related cirrhosis. The amount of alcohol consumed and whether excessive drinking continues after the identification of pre-cirrhotic liver damage are key risk factors. Female sex, ethnicity, obesity, coffee consumption, cigarette smoking, and exposure to other causes of liver injury also influence the risk of disease development. More recently several genetic loci have been robustly associated with the risk for developing significant alcohol-related liver disease. It remains unclear whether additional risk factors are involved in the development of the clinical syndrome of alcoholic hepatitis, but the genetic evidence is suggestive.

Update on cardiovascular risk in nonalcoholic fatty liver disease

PURPOSE OF REVIEW

To summarize recent evidence demonstrating increased cardiovascular disease (CVD) risk, and how CVD risk may be reduced, in patients with nonalcoholic fatty liver disease (NAFLD).

RECENT FINDINGS

NAFLD is a multisystem disease, defined by a spectrum of liver fat-associated conditions extending from simple steatosis, to inflammation, fibrosis and cirrhosis. NAFLD not only increases the risk of liver morbidity and mortality but also increases the risk of CVD morbidity and mortality and is associated with recognized CVD risk factors such as hypertension, atherogenic dyslipidaemia, type 2 diabetes mellitus and chronic kidney disease. Evidence suggests that the liver fibrosis stage may be a strong CVD risk factor. Lifestyle measures (e.g. weight loss and increased physical activity) are effective in improving CVD risk factors. Hypoglycaemic agents, such as the peroxisome proliferator-activated receptor gamma agonist pioglitazone and the glucagon-like peptide-1 receptor agonist liraglutide, reduce cardiovascular risk and may improve liver histology. Statin and antihypertensive treatments are well tolerated and currently it is unclear whether novel antifibrotic drugs will reduce CVD risk.

SUMMARY

Assessment and treatment of increased cardiovascular risk is important in patients with NAFLD. If not contra-indicated, pioglitazone or a glucagon-like peptide 1 agonist should be considered and may benefit both CVD risk and early liver disease.

The Endless Sources of Hepatocellular Carcinoma Heterogeneity

Hepatocellular carcinoma (HCC) represents a global health problem. The incidence keeps increasing and current therapeutic options confer limited benefits to the patients. Tumor heterogeneity plays a central role in this context, limiting the availability of predictive biomarkers and complicating the criteria used to choose the most suitable therapeutic option. HCC heterogeneity occurs at different levels: within the population (inter-patient heterogeneity) and within tumors from the same patient (intra-patient and intra-tumor heterogeneity). Experts in the field have made many efforts to classify the patients based on clinicopathological characteristics and molecular signatures; however, there is still much work ahead to be able to integrate the extra-tumor heterogeneity that emerges from the complexity of the tumor microenvironment, which plays a critical role in the pathogenesis of the disease and therapy responses. In this review, we summarize tumor intrinsic and extrinsic sources of heterogeneity of the most common etiologies of HCC and summarize the most recent discoveries regarding the evolutionary trajectory of liver cancer cells and the influence of tumor-extrinsic factors such as the microbiome and the host immune system. We further highlight the potential of novel high-throughput methodologies to contribute to a better understanding of this devastating disease and to the improvement of the clinical management of patients.

Alcohol-Related Liver Disease: Basic Mechanisms and Clinical Perspectives

Alcohol-related liver disease (ALD) refers to the liver damage occurring due to excessive alcohol consumption and involves a broad spectrum of diseases that includes liver steatosis, steatohepatitis, hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The progression of ALD is mainly associated with the amount and duration of alcohol usage; however, it is also influenced by genetic, epigenetic, and environmental factors. The definite diagnosis of ALD is based on a liver biopsy, although several non-invasive diagnostic tools and serum biomarkers have emerging roles in the early detection of ALD. While alcohol abstinence and nutritional support remain the cornerstone of ALD treatment, growing evidence has revealed that the therapeutic agents that target oxidative stress or gut-liver axis, inflammatory response inhibition, and liver regeneration enhancement also play a role in ALD management. Furthermore, microRNAs modulation and mesenchymal stem cell-based therapy have emerging potential as ALD therapeutic options. This review summarizes the updated understanding of the pathophysiology, diagnosis, and novel therapeutic approaches for ALD.

Mechanisms and disease consequences of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the leading chronic liver disease worldwide. Its more advanced subtype, nonalcoholic steatohepatitis (NASH), connotes progressive liver injury that can lead to cirrhosis and hepatocellular carcinoma. Here we provide an in-depth discussion of the underlying pathogenetic mechanisms that lead to progressive liver injury, including the metabolic origins of NAFLD, the effect of NAFLD on hepatic glucose and lipid metabolism, bile acid toxicity, macrophage dysfunction, and hepatic stellate cell activation, and consider the role of genetic, epigenetic, and environmental factors that promote fibrosis progression and risk of hepatocellular carcinoma in NASH.

Increasing prevalence of NAFLD/NASH among children, adolescents and young adults from 1990 to 2017: a population-based observational study

OBJECTIVE

To describe the prevalence and variations of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH) among children and adolescents (CADs) and young adults (YADs).

DESIGN

A population-based observational study.

SETTING

Annual cases and prevalence of NAFLD/NASH from 1990 to 2017, by sex, region and country were collected from the Global Burden of Disease database.

MAIN OUTCOME MEASURES

The estimated annual percentage change, which was calculated by a regression line, was used to quantify the temporal trends in NAFLD/NASH burden among young people at the global, regional and national levels.

RESULTS

Globally, NAFLD/NASH incidence increased from 19.34 million in 1990 to 29.49 million in 2017 among CADs, with an annual increase of 1.35%. Additionally, in YADs, the number of cases and NAFLD/NASH prevalence significantly increased during this period, independent of sex and region. The greatest NAFLD/NASH increase was in North Africa and the Middle East. Almost all countries showed an increasing trend from 1990 to 2017, with the most pronounced increase observed in the developed regions.

CONCLUSIONS

The epidemiology of NAFLD/NASH in young people has changed considerably over the last three decades. Both the prevalence and number of cases have increased irrespective of sex, age and region. This phenomenon can result in a predictable increase in chronic liver disease burden in the near future. Understanding the prevalence of NAFLD/NASH and its variations is of paramount importance to develop strategies to implement public health policy.

Genetic predisposition similarities between NASH and ASH: Identification of new therapeutic targets

Fatty liver disease can be triggered by a combination of excess alcohol, dysmetabolism and other environmental cues, which can lead to steatohepatitis and can evolve to acute/chronic liver failure and hepatocellular carcinoma, especially in the presence of shared inherited determinants. The recent identification of the genetic causes of steatohepatitis is revealing new avenues for more effective risk stratification. Discovery of the mechanisms underpinning the detrimental effect of causal mutations has led to some breakthroughs in the comprehension of the pathophysiology of steatohepatitis. Thanks to this approach, hepatocellular fat accumulation, altered lipid droplet remodelling and lipotoxicity have now taken centre stage, while the role of adiposity and gut-liver axis alterations have been independently validated. This process could ignite a virtuous research cycle that, starting from human genomics, through omics approaches, molecular genetics and disease models, may lead to the development of new therapeutics targeted to patients at higher risk. Herein, we also review how this knowledge has been applied to: a) the study of the main PNPLA3 I148M risk variant, up to the stage of the first in-human therapeutic trials; b) highlight a role of MBOAT7 downregulation and lysophosphatidyl-inositol in steatohepatitis; c) identify IL-32 as a candidate mediator linking lipotoxicity to inflammation and liver disease. Although this precision medicine drug discovery pipeline is mainly being applied to non-alcoholic steatohepatitis, there is hope that successful products could be repurposed to treat alcohol-related liver disease as well.

Pleiotropy within gene variants associated with nonalcoholic fatty liver disease and traits of the hematopoietic system

Genome-wide association studies of complex diseases, including nonalcoholic fatty liver disease (NAFLD), have demonstrated that a large number of variants are implicated in the susceptibility of multiple traits — a phenomenon known as pleiotropy that is increasingly being explored through phenome-wide association studies. We focused on the analysis of pleiotropy within variants associated with hematologic traits and NAFLD. We used information retrieved from large public National Health and Nutrition Examination Surveys, Genome-wide association studies, and phenome-wide association studies based on the general population and explored whether variants associated with NAFLD also present associations with blood cell-related traits. Next, we applied systems biology approaches to assess the potential biological connection/s between genes that predispose affected individuals to NAFLD and nonalcoholic steatohepatitis, and genes that modulate hematological-related traits—specifically platelet count. We reasoned that this analysis would allow the identification of potential molecular mediators that link NAFLD with platelets. Genes associated with platelet count are most highly expressed in the liver, followed by the pancreas, heart, and muscle. Conversely, genes associated with NAFLD presented high expression levels in the brain, lung, spleen, and colon. Functional mapping, gene prioritization, and functional analysis of the most significant loci (P < 1 × 10^-8) revealed that loci involved in the genetic modulation of platelet count presented significant enrichment in metabolic and energy balance pathways. In conclusion, variants in genes influencing NAFLD exhibit pleiotropic associations with hematologic traits, particularly platelet count. Likewise, significant enrichment of related genes with variants influencing platelet traits was noted in metabolic-related pathways. Hence, this approach yields novel mechanistic insights into NAFLD pathogenesis.

Genetic and epigenetic disease modifiers: non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD)

Inter-individual and inter-ethnic differences and difference in the severity and progression of liver disease among patients with non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) suggests the involvement of genetic and epigenetic factors in their pathogenesis. This article reviews the genetic and epigenetic modifiers in patients with NAFLD and ALD. Evidence regarding the genetic and epigenetic disease modifiers of NAFLD and ALD was reviewed by searching the available literature. Both genome wide association studies (GWAS) and candidate gene studies pertaining to the pathogenesis in both diseases were included. Clinical implications of the available information are also discussed. Several studies have shown association of both NAFLD and ALD with I148M PNPLA3 variant. In addition to the higher prevalence of hepatic steatosis, the I148M PNPLA3 variant is also associated with severity of liver disease and risk of hepatocellular carcinoma (HCC). TM6SF2 is the other genetic variant shown to be significantly associated with hepatic steatosis and cirrhosis in patients with NAFLD and ALD. The Membrane bound O-acyltransferase domain-containing 7 (MBOAT7) genetic variant is also associated with both NAFLD and ALD. In addition to these mutations, several variants related to the genes involved in glucose metabolism, insulin resistance, lipid metabolism, oxidative stress, inflammatory pathways, fibrosis have also been shown to be the disease modifiers in patients with NAFLD and ALD. Epigenetics involving several micro RNAs and DNA methylation could also modify the disease course in NAFLD and ALD. In conclusion the available literature suggests that genetics and epigenetics are involved in the pathogenesis of NAFLD and ALD which may affect the disease prevalence, severity and response to treatment in these patients.

Characterizing the mechanism behind the progression of NAFLD to hepatocellular carcinoma

Hepatocellular carcinoma (HCC) developed in non-alcoholic fatty liver disease (NAFLD) individuals presents substantial clinical and biological characteristics, which remain to be elucidated. Its occurrence in noncirrhotic patients raises issues regarding surveillance strategies, which cannot be considered as cost-effective given the high prevalence of obesity and metabolic syndrome, and furthermore delineates specific oncogenic process that could be targeted in the setting of primary or secondary prevention. In this context, the identification of a genetic heterogeneity modulating HCC risk as well as specific biological pathways have been made possible through genome-wide association studies, development of animal models and in-depth analyses of human samples at the pathological and genomic levels. These advances must be confirmed and pursued to pave the way for personalized management of NAFLD-related HCC.

Hepatic Fat-Genetic Risk Score Predicts Hepatocellular Carcinoma in Patients With Cirrhotic HCV Treated With DAAs

BACKGROUND AND AIMS

Genetic factors and steatosis predispose to hepatocellular carcinoma (HCC) in patients with chronic hepatitis C virus; however, their impact in patients with cirrhosis cured by direct-acting antivirals (DAAs) is still undefined. We assessed the association between a genetic risk score (GRS) of hepatic fat accumulation, combining variants in PNPLA3 (patatin-like phospholipase domain containing 3), MBOAT7 (membrane bound O-acyltransferase domain containing 7), TM6SF2 (transmembrane 6 superfamily member 2), GCKR (glucokinase regulator), and HCC in patients treated with DAAs.

APPROACH AND RESULTS

We considered 509 consecutive patients with HCV cirrhosis (defined histologically or when liver stiffness ≥12 kPa) treated with DAAs. HCC was diagnosed according to international recommendations. GRS was calculated from the weighted impact of single variants on hepatic fat content quantified by H¹ spectrometry in the general population (Dallas Heart Study). During a median follow-up of 43 (3-57) months after DAA start, 36 of 452 (8%) patients developed de novo HCC, 4-year cumulative probability being 9% (95% confidence interval 7%-12%). Male sex (hazard ratio [HR] 2.54, P = 0.02), diabetes (HR 2.39, P = 0.01), albumin (HR 0.35, P = 0.001), and GRS score >0.597 (HR 2.30, P = 0.04) were independent predictors of de novo HCC. In contrast, single genetic risk variants were not useful in stratifying HCC risk. The proportion of patients who developed HCC according to the combination of the independent risk factors ranged from 11% to 67%. HCC recurred in 28 of 57 (49%) patients with previous history; diabetes and ethnicity were the only independent predictors of HCC recurrence.

CONCLUSIONS

In a large cohort of DAA-treated patients with cirrhotic HCV, GRS was associated with de novo HCC independently of classical risk factors, including liver disease severity. These data suggest that hepatic fat (i.e., lipotoxicity) promotes HCC in this setting and may represent a target for chemoprevention. Combination of clinical and genetic predictors may improve HCC risk stratification.

Established and emerging factors affecting the progression of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease affecting approximately 25% of the global population. Although a majority of NAFLD patients will never experience liver-related symptoms it is estimated that 5-10% will develop cirrhosis-related complications with risk of death or need for liver transplantation. NAFLD is closely associated with cardiovascular disease and components of the metabolic syndrome. However, NAFLD is not uncommon in lean individuals and may in these subjects represent a different entity with separate pathophysiological mechanisms involved implying a higher risk for development of end-stage liver disease. There is considerable fluctuation in the histopathological course of NAFLD that may partly be attributed to lifestyle factors and dietary composition. Nutrients such as fructose, monounsaturated fatty acids, and trans-fatty acids may aggravate NAFLD. Presence of type 2 diabetes mellitus seems to be the most important clinical predictor of liver-related morbidity and mortality in NAFLD. Apart from severity of the metabolic syndrome, genetic polymorphisms and environmental factors, such as moderate alcohol consumption, may explain the variation in histopathological and clinical outcome among NAFLD patients.

Sofosbuvir and daclatasvir are safe and effective in treatment of recurrent hepatitis C virus in Egyptian patients underwent living donor liver transplantation

Background

Liver transplant population has been considered as a special population in the treatment of hepatitis C virus infection, not only because of lower sustained virological response (SVR) rates in comparison with pretransplant setting, but also for other aspects (i.e., immunosuppressive therapy, renal function, drug–drug interactions). We aimed to evaluate the efficacy and safety of the combined treatment with sofosbuvir and daclatasvir with or without ribavirin in liver transplant recipients with recurrent hepatitis C following transplantation and screening for the development of hepatocellular carcinoma during treatment, after the end of treatment, or during follow-up. This multicenteric prospective study was conducted in Egypt. This study included 40 patients who underwent living donor liver transplantation that started treatment at least 3 months following transplantation. All participants received 400 mg sofosbuvir once daily plus daclatasvir 60 mg daily ± ribavirin. Treatment lasted for up to 24 weeks, and participants were followed up as outpatients monthly for 12 and 24 weeks and 36 weeks post-treatment to determine sustained virological response (SVR12 and SVR24), considered to be a cure and detection of any changes in tumor markers or radiological imaging during follow-up.

Results

In the current study, 40 patients (100%) have good response to treatment during treatment and during follow-up (SVR 12 was 100%). No abnormal side effects to treatment were detected; also, no drug–drug interactions were noted during the treatment.

Conclusions

Treatment of HCV after living donor liver transplantation with combined sofosbuvir and daclatasvir is safe and well-tolerated and provides high rates of SVR.

Association between steatohepatitis biomarkers and hepatocellular carcinoma after hepatitis C elimination

BACKGROUND

A strong association between chronic hepatitis C (CHC) and hepatic steatosis has been reported. However, the influence of steatohepatitis on hepatocellular carcinoma (HCC) after hepatitis C virus (HCV) elimination remains unclear.

AIM

To evaluate the development of HCC after HCV cure using a new steatohepatitis-related biomarker.

METHODS

This cohort study analysed the prospective database of 290 CHC patients without a history of HCC who achieved HCV elimination by direct-acting antivirals. We calculated the FibroScan-aspartate aminotransferase (FAST) score 12 weeks after the end of treatment (pw12). The risk of HCC was analysed using the multivariable Cox proportional hazard model.

RESULTS

HCV genotype (GT)1 was most prevalent at 72.4%, followed by GT2 (26.6%). Median follow-up period was 4.2 years (IQR 3.1-4.5). The cumulative HCC incidence for a FAST score ≥ 0.35 was significantly higher than that for a FAST score < 0.35 (log-rank test: P < 0.001). The annual HCC incidence rate for a FAST score ≥ 0.35 was significantly higher than that for a FAST score < 0.35, in patients with liver stiffness measurement (LSM) ≥10 kPa (adjusted hazard ratio [HR] 4.41, 95% confidence interval [CI] 1.30-15.0, P = 0.018). After adjusting for variables, including age, albumin, alpha-fetoprotein, the patatin-like phospholipase domain-containing the 3 (PNPLA3) rs738409 genotype, and pw12 fibrosis markers with FIB-4, non-alcoholic fatty liver disease fibrosis score, and LSM, FAST score ≥ 0.35 was associated with the development of HCC (adjusted HR 4.42, 95% CI 1.02-19.9, P = 0.043).

CONCLUSIONS

Steatohepatitis-related biomarkers with the FAST score are helpful for predicting the development of HCC after HCV elimination.

Genetic and metabolic factors: the perfect combination to treat metabolic associated fatty liver disease

The prevalence of nonalcoholic or more recently re-defined metabolic associated fatty liver disease (MAFLD) is rapidly growing worldwide. It is characterized by hepatic fat accumulation exceeding 5% of liver weight not attributable to alcohol consumption. MAFLD refers to an umbrella of conditions ranging from simple steatosis to nonalcoholic steatohepatitis which may finally progress to cirrhosis and hepatocellular carcinoma. MAFLD is closely related to components of the metabolic syndrome and to environmental factors. In addition to the latter, genetic predisposition plays a key role in MAFLD pathogenesis and strictly contributes to its progressive forms. The candidate genes which have been related to MAFLD hereditability are mainly involved in lipids remodeling, lipid droplets assembly, lipoprotein packaging and secretion, de novo lipogenesis, and mitochondrial redox status. In the recent years, it has emerged the opportunity to translate the genetics into clinics by aggregating the genetic variants mostly associated with MAFLD in polygenic risk scores. These scores might be used in combination with metabolic factors to identify those patients at higher risk to develop more severe liver disease and to schedule an individual therapeutic approach.

Genetic Variation in HSD17B13 Reduces the Risk of Developing Cirrhosis and Hepatocellular Carcinoma in Alcohol Misusers

BACKGROUND AND AIMS

Carriage of rs738409:G in patatin-like phospholipase domain containing 3 (PNPLA3) is associated with an increased risk for developing alcohol-related cirrhosis and hepatocellular carcinoma (HCC). Recently, rs72613567:TA in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) was shown to be associated with a reduced risk for developing alcohol-related liver disease and to attenuate the risk associated with carriage of PNPLA3 rs738409:G. This study explores the risk associations between these two genetic variants and the development of alcohol-related cirrhosis and HCC.

APPROACH AND RESULTS

Variants in HSD17B13 and PNPLA3 were genotyped in 6,171 participants, including 1,031 with alcohol-related cirrhosis and HCC, 1,653 with alcohol-related cirrhosis without HCC, 2,588 alcohol misusers with no liver disease, and 899 healthy controls. Genetic associations with the risks for developing alcohol-related cirrhosis and HCC were determined using logistic regression analysis. Carriage of HSD17B13 rs72613567:TA was associated with a lower risk for developing both cirrhosis (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.72-0.88; P = 8.13 × 10^-6 ) and HCC (OR, 0.77; 95% CI, 0.68-0.89; P = 2.27 × 10^-4 ), whereas carriage of PNPLA3 rs738409:G was associated with an increased risk for developing cirrhosis (OR, 1.70; 95% CI, 1.54-1.88; P = 1.52 × 10^-26 ) and HCC (OR, 1.77; 95% CI, 1.58-1.98; P = 2.31 × 10^-23 ). These associations remained significant after adjusting for age, sex, body mass index, type 2 diabetes, and country. Carriage of HSD17B13 rs72613567:TA attenuated the risk for developing cirrhosis associated with PNPLA3 rs738409:G in both men and women, but the protective effect against the subsequent development of HCC was only observed in men (OR_allelic , 0.75; 95% CI, 0.64-0.87; P = 1.72 × 10^-4 ).

CONCLUSIONS

Carriage of variants in PNPLA3 and HSD17B13 differentially affect the risk for developing advanced alcohol-related liver disease. A genotypic/phenotypic risk score might facilitate earlier diagnosis of HCC in this population.

Liver fibrogenesis: un update on established and emerging basic concepts

Liver fibrogenesis is defined as a dynamic and highly integrated process occurring during chronic injury to liver parenchyma that can result in excess deposition of extracellular matrix (ECM) components (i.e., liver fibrosis). Liver fibrogenesis, together with chronic inflammatory response, is then primarily involved in the progression of chronic liver diseases (CLD) irrespective of the specific etiology. In the present review we will first offer a synthetic and updated overview of major basic concepts in relation to the role of myofibroblasts (MFs), macrophages and other hepatic cell populations involved in CLD to then offer an overview of established and emerging issues and mechanisms that have been proposed to favor and/or promote CLD progression. A special focus will be dedicated to selected issues that include emerging features in the field of cholangiopathies, the emerging role of genetic and epigenetic factors as well as of hypoxia, hypoxia-inducible factors (HIFs) and related mediators.

A common variant in PNPLA3 is associated with age at diagnosis of NAFLD in patients from a multi-ethnic biobank

BACKGROUND & AIMS

The Ile138Met variant (rs738409) in the PNPLA3 gene has the largest effect on non-alcoholic fatty liver disease (NAFLD), increasing the risk of progression to severe forms of liver disease. It remains unknown if the variant plays a role in age of NAFLD onset. We aimed to determine if rs738409 impacts on the age of NAFLD diagnosis.

METHODS

We applied a novel natural language processing (NLP) algorithm to a longitudinal electronic health records (EHR) dataset of >27,000 individuals with genetic data from a multi-ethnic biobank, defining NAFLD cases (n = 1,703) and confirming controls (n = 8,119). We conducted i) a survival analysis to determine if age at diagnosis differed by rs738409 genotype, ii) a receiver operating characteristics analysis to assess the utility of the rs738409 genotype in discriminating NAFLD cases from controls, and iii) a phenome-wide association study (PheWAS) between rs738409 and 10,095 EHR-derived disease diagnoses.

RESULTS

The PNPLA3 G risk allele was associated with: i) earlier age of NAFLD diagnosis, with the strongest effect in Hispanics (hazard ratio 1.33; 95% CI 1.15-1.53; p <0.0001) among whom a NAFLD diagnosis was 15% more likely in risk allele carriers vs. non-carriers; ii) increased NAFLD risk (odds ratio 1.61; 95% CI 1.349-1.73; p <0.0001), with the strongest effect among Hispanics (odds ratio 1.43; 95% CI 1.28-1.59; p <0.0001); iii) additional liver diseases in a PheWAS (p <4.95 × 10^-6) where the risk variant also associated with earlier age of diagnosis.

CONCLUSION

Given the role of the rs738409 in NAFLD diagnosis age, our results suggest that stratifying risk within populations known to have an enhanced risk of liver disease, such as Hispanic carriers of the rs738409 variant, would be effective in earlier identification of those who would benefit most from early NAFLD prevention and treatment strategies.

LAY SUMMARY

Despite clear associations between the PNPLA3 rs738409 variant and elevated risk of progression from non-alcoholic fatty liver disease (NAFLD) to more severe forms of liver disease, it remains unknown if PNPLA3 rs738409 plays a role in the age of NAFLD onset. Herein, we found that this risk variant is associated with an earlier age of NAFLD and other liver disease diagnoses; an observation most pronounced in Hispanic Americans. We conclude that PNPLA3 rs738409 could be used to better understand liver disease risk within vulnerable populations and identify patients that may benefit from early prevention strategies.