PNPLA3 Rs738409 Research Articles

O-1 THE ROLE OF PNPLA3 AND TM6SF2 POLYMORPHISMS ON LIVER FIBROSIS AND METABOLIC ABNORMALITIES IN BRAZILIAN PATIENTS WITH CHRONIC HEPATITIS C

Despite the growing body of knowledge about TM6SF2 and PNPLA3 polymorphisms in non-alcoholic fatty liver disease, their influence in the spectrum of HCV liver disease is not yet fully defined. Besides that, admixed populations, such as Brazilians, were not included in most of the studies. Describe the prevalence of these polymorphisms in Brazilians with chronic hepatitis C, and to assess their association with liver fibrosis and other components of the metabolic syndrome. This cross-sectional study enrolled 365 treatment-naïve patients with HCV and 134 healthy individuals. TM6SF2 (rs58542926 c.499C>T) and PNPLA3 (rs738409 c.444C>G) polymorphisms were evaluated regarding their association with clinical and laboratory data, histological liver steatosis and fibrosis, and with components of the metabolic syndrome. In HCV subjects, the frequencies of TM6SF2 CC and CT + TT were 89% and 11%, while PNPLA3 frequencies of CC and CG + GG were 51.4% and 48.6%. In the univariate logistic regression analysis, the TM6SF2 CT + TT genotype in HCV was associated with significant liver fibrosis (p = 0.047; OR:1.953; 95% CI:1.009-3.788) however it was not confirmed by multivariate analysis. In comparison to the CT + TT genotype, the TM6SF2 CC genotype in HCV was associated higher frequency of arterial hypertension (p = 0.032), obesity (p = 0.030), metabolic syndrome (p = 0.014) and lower total cholesterol levels (p=0.036). The PNPLA3 GG subjects had lower body mass index than CG/ CC individuals (p = 0.047). None of the polymorphisms, or their combinations, was independently associated with hepatic steatosis. In this evaluation of an admixed HCV population, neither TM6SF2 nor PNPLA3 polymorphisms were independently associated with hepatic steatosis or fibrosis.

O-14 A SYNERGISTIC EFFECT OF PNPLA3 GENE POLYMORPHISM AND INSULIN RESISTANCE INCREASES THE RISK TO NON-ALCOHOLIC FATTY LIVER DISEASE IN PATIENTS WITH POLYCYSTIC OVARY SYNDROME

The patatin-like phospholipase 3 gene polymorphism (PNPLA3) has been consistently associated with non-alcoholic fatty liver disease (NAFLD) and its histological severity on different populations. In addition, increasing evidence demonstrates the association of NAFLD and polycystic ovary syndrome (PCOS), both associated with obesity, insulin resistance (IR) and metabolic syndrome (MS). Describe the prevalence of the PNPLA3 gene polymorphism and its impact on NAFLD susceptibility and progression in women with PCOS. This was a cross-sectional study enrolling 163 patients with PCOS. All the patients were evaluated for the presence of the PNPLA3 (rs738409 c.444C>G) polymorphism, hepatic steatosis at ultrasound and metabolic disorders. In patients with steatosis, transient hepatic elastography was performed to assess liver stiffness. In this population, evidence of hepatic steatosis was observed in 72.4% of them. The polymorphism was present in heterozygosis (CG) in 41.7% and in homozygosis (GG) in 8% of patients and was not statistically associated with the occurrence of NAFLD or clinically significant fibrosis (≥ F2). IR had a prevalence of 75% and, after evaluation by a multiple regression model, it was the main factor associated with the risk of NAFLD (B = 1.405, p = 0.026). A synergistic effect between IR and the presence of polymorphism on increasing the risk of NAFLD was observed (B = 2.047, p = 0.042). HDL values ≥ 49 mg/dL showed a negative association with NAFLD (B = - 1.578, p = 0.001). MS and IR, waist circumference, higher values of transaminases and lower levels of dehydroepiandrosterone sulfate were associated with clinically significant fibrosis. The PNPLA3 gene polymorphism did not present an independent association either with NAFLD or the development of clinically significant fibrosis in women with PCOS. However, the polymorphism interacts synergistically with IR and increases the risk of NAFLD.

OP-1 GUT METATRANSCRIPTOMICS AND METABOLOMICS REVEAL ASSOCIATION OF CYSTEINE AND PURINE METABOLISMS WITH METABOLIC ASSOCIATED FATTY LIVER DISEASE (MAFLD)

The gut microbiome represents a niche for biomarkers discovery to risk-stratify MAFLD patients. However, each population may have unique microbiome signatures and studies are needed in Latin America where MAFLD prevalence and severity are high. To identify gut metatranscriptome and metabolome signatures associated with MAFLD and steatohepatitis (SH) in Argentina. Stool samples, diet, demographic and clinical data were obtained from 33 biopsy-proven patients (12 simple steatosis -SS- and 21 SH) and 19 healthy volunteers (HV). PNPLA3 rs738409 SNP was genotyped. HPLC, flow injection analysis with MS/MS in tandem and MetaboAnalyst-v4.0 were used for metabolomics. RNA-seq was performed in NovaSeq6000®. bioBakery-v1.8 and Maaslin2-v1.2.0 were used for data analysis. BMI was higher in MAFLD patients, particularly in SH (q=4.49e-06). After adjusting for BMI, 89 and 53 gene family clusters were differentially expressed between HV and MAFLD and between SS and SH, respectively (q<0.1). Pathways related to sulfur oxidation, short-chain fatty acid metabolism, purine metabolism and lipopolysaccharide synthesis were enriched in MAFLD patients when compared with HV and in SH when compared with SS, whereas folate synthesis was enriched in SS patients (q<0.1). Gene expression associated with Desulfobacteraceae bacteria harbored most of the functional features of MAFLD patients when compared with HV, and of SH patients within the case group (Figure). The PNPLA3 GG genotype was related to decreased hydrolysis of glycerolipids, high expression of Clostridium cadaveris and low expression of Desulfobacteraceae bacteria associated genes (q<0.1). Higher concentrations of xanthine, implicated in purine metabolism, and of the sulfur amino acid cysteine were detected in the stool of MAFLD patients when compared with HV, and of SH patients within the case group (BMI-adjusted q<0.1). Cysteine and purine metabolisms are strongly related to MAFLD and SH in Argentinian patients. Cysteine and xanthine could be useful as potential biomarkers.

Adiponutrin and Adiponectin Gene Variants in Indonesian Patients with Non-Alcoholic Fatty Liver Disease: a Preliminary Study

BackgroundVariants of adiponutrin (PNPLA3) and adiponectin (ADIPOQ) genes were considered to be associated with non-alcoholic fatty liver disease (NAFLD). Although the prevalence of NAFLD is increasing, there are limited numbers of studies about the association in Indonesian population.ObjectiveTo confirm whether specific variants of adiponutrin (PNPLA3) and adiponectin (ADIPOQ) genes are associated with NAFLD in Indonesian patients.MethodsData and DNA of 152 participants were obtained from a previous study in Dr. Kariadi Hospital, Semarang, Indonesia. PCR-RFLP analysis was performed for detection of PNPLA3 rs738409 and ADIPOQ rs2241767 variants. The diagnosis and severity of NAFLD were assessed according to NAFLD activity score (NAS) based on histopathology assessment of liverbiopsy.ResultsAllele G of PNPLA3rs738409 was associated with NAFLD in both bivariate (p=0.009, OR 2.52, CI 95% 1.25–5.07) and multivariate (p=0.008, OR 2.62, CI 95% 1.29%–5.32%) analysis, while ADIPOQ rs2241767 had no significant association. In NAFLD participants, both genotypes showed allele G was higher in the group of possible non-alcoholic steatohepatitis (NASH) – NASH (NAS &gt;2) than in the simple steatosis group (NAS &lt;2) i.e. 40.0% vs. 3.75% for the rs2241767 variant and 23.75% vs. 1.25% for the rs738409 variant, without significant association.ConclusionVariant PNPLA3 rs738409 was associated with NAFLD incidence in studied population. Among NAFLD participants, the frequency of both variants were found higher in the possible NASH – NASH group, yet needs to be confirmed with more participants and a multicenter study.Data and DNA of 152 participants were obtained from a previous study in Dr. Kariadi Hospital, Semarang, Indonesia. PCR-RFLP analysis was performed for detection of PNPLA3 rs738409 and ADIPOQ rs2241767 variants. The diagnosis and severity of NAFLD were assessed according to NAFLD activity score (NAS) based on histopathology assessment of liverbiopsy.

Non-alcoholic fatty liver disease-related risk of cardiovascular disease and other cardiac complications.

Non-alcoholic fatty liver disease (NAFLD) affects approximately 25% of the global adult population. The aim of this narrative review is to describe the associations between NAFLD and cardiovascular disease (CVD), arrhythmias, cardiac conduction defects, myocardial remodelling and heart failure. We also discuss the potential mechanisms that mediate or attenuate the strength of these associations, and briefly summarize the effect of treatments that both ameliorate NAFLD and decrease risk of CVD. Searches of PubMed were performed by the two authors using the terms listed in Appendix. We limited the timeframe to the last decade due to the vast amount of research in the field (up to April 2021) for meta-analyses, reviews and original papers. Only articles published in English were considered. NAFLD is associated with an increased risk of fatal/non-fatal CVD events and other cardiac and arrhythmic complications (left ventricular hypertrophy, aortic-valve sclerosis and certain arrhythmias), independently of common CVD risk factors. There are probably several underlying mechanisms, including hepatic/systemic insulin resistance, atherogenic dyslipidaemia, hypertension and pro-atherogenic, pro-coagulant and pro-inflammatory mediators released from the steatotic/inflamed liver that may be involved. Some genetic polymorphisms, such as PNPLA3 (rs738409 C>G) and TM6SF2 (rs58542926 C>T), may worsen the liver disease, but also attenuate the strength of the association between NAFLD and CVD, possibly via their effects on lipoprotein metabolism. Of the currently tested drugs for treating NAFLD that also benefit the vasculature, pioglitazone and GLP-1 receptor agonists are the most promising. The complex interplay between the liver and cardiometabolic risk factors contributes to CVD, arrhythmias and cardiac disease in NAFLD. There is an urgent need for a multidisciplinary approach to manage both liver disease and cardiometabolic risk, and to test the cardiovascular and cardiac effects of new drugs for NAFLD.

Associations of Nutrient Intake Changes During Childhood with Adolescent Hepatic Fat: The Exploring Perinatal Outcomes Among CHildren Study

To examine associations of dietary changes from childhood to adolescence with adolescent hepatic fat and whether the PNPLA3 rs738409 risk allele, a strong genetic risk factor for hepatic fat, modifies associations. Data were from 358 participants in the Exploring Perinatal Outcomes among CHildren (EPOCH) study, a longitudinal cohort in Colorado. Diet was assessed by food frequency questionnaire in childhood (approximately 10years of age) and adolescence (approximately 16years of age) and converted to nutrient densities. Hepatic fat was assessed in adolescence by magnetic resonance imaging. Linear regression was used to test associations of dietary changes from childhood to adolescence with adolescent hepatic fat. Increases in fiber, vegetable protein, and polyunsaturated fat intake from childhood to adolescence were associated with lower adolescent hepatic fat, and increases in animal protein were associated with higher hepatic fat (β per 5-unit increase on log-hepatic fat: -0.12 [95% CI, -0.21 to -0.02] for ▵fiber; -0.26 [95% CI, -0.45 to -0.07] for ▵vegetable protein; -0.18 [95% CI, -0.35 to -0.02] for ▵polyunsaturated fat; 0.13 [95% CI, 0.04-0.22] for ▵animal protein). There was evidence of effect modification by PNPLA3 variant, whereby inverse associations of ▵fiber and ▵vegetable protein and positive associations of ▵saturated fat with adolescent hepatic fat were stronger in risk allele carriers. Most conclusions were similar after adjusting for obesity in adolescence, but associations of ▵saturated fat with hepatic fat were attenuated toward the null. Our results suggest that nutrient intake changes between childhood and adolescence, particularly decreases in fiber and vegetable protein and increases in saturated fat intake, interact with the PNPLA3 variant to predict higher hepatic fat in adolescence, and may be targets for reducing hepatic fat in high-risk youth.

PNPLA3 and TLL-1 Polymorphisms as Potential Predictors of Disease Severity in Patients With COVID-19.

Albeit the pathogenesis of COVID-19 remains unclear, host’s genetic polymorphisms in genes involved in infection and reinfection, inflammation, or immune stimulation could play a role in determining the course and outcome. We studied in the early phase of pandemic consecutive patients (N = 383) with SARS-CoV-2 infection, whose subsequent clinical course was classified as mild or severe, the latter being characterized by admission to intensive therapy unit or death. Five host gene polymorphisms (MERTK rs4374383, PNPLA3 rs738409, TLL-1 rs17047200, IFNL3 rs1297860, and INFL4 rs368234815) were assessed by using whole nucleic acids extracted from nasopharyngeal swabs. Specific protease cleavage sites of TLL-1 on the SARS-CoV-2 Spike protein were predicted in silico. Male subjects and older patients were significantly at higher risk for a severe outcome (p = 0.02 and p < 0.001, respectively). By considering patients ≤65 years, after adjusting for potential confounding due to sex, an increased risk of severe outcome was found in subjects with the GG genotype of PNPLA3 (adj-OR: 4.69; 95% CI = 1.01–22.04) or TT genotype of TLL-1 (adj-OR=9.1; 95% CI = 1.45–57.3). In silico evaluation showed that TLL-1 is potentially involved in the Spike protein cleavage which is essential for viral binding and entry into the host cells using the host receptor angiotensin-converting enzyme 2 (ACE2). Subjects carrying a GG genotype in PNPLA3 gene might have a constitutive upregulation of the NLRP3 inflammasome and be more prone to tissue damage when infected by SARS-CoV-2. The TT genotype in TLL-1 gene might affect its protease activity on the SARS-CoV-2 Spike protein, enhancing the ability to infect or re-infect host’s cells. The untoward effect of these variants on disease course is evident in younger patients due to the relative absence of comorbidities as determinants of prognosis. In the unresolved pathogenetic scenery of COVID-19, the identification of genetic variants associates with more prolonged course or with a severe outcome of infection would support the development of predictive tools useful to stratify subjects by risk class at presentation. Moreover, the individuation of key genes could contribute to a better understanding of the pathways involved in the pathogenesis, giving the basis for rational therapeutic approaches.

Circulating Fatty Acids Associated with Advanced Liver Fibrosis and Hepatocellular Carcinoma in South Texas Hispanics.

Hispanics in South Texas have high rates of hepatocellular carcinoma (HCC) and nonalcoholic fatty liver disease (NAFLD). Liver fibrosis severity is the strongest predictive factor of NAFLD progression to HCC. We examined the association between free fatty acids (FA) and advanced liver fibrosis or HCC in this population. We quantified 45 FAs in plasma of 116 subjects of the Cameron County Hispanic Cohort, 15 Hispanics with HCC, and 56 first/second-degree relatives of Hispanics with HCC. Liver fibrosis was assessed by FibroScan. Advanced liver fibrosis was significantly associated with low expression of very long chain (VLC) saturated FAs (SFA), odd chain SFAs, and VLC n-3 polyunsaturated FAs [PUFA; AOR; 95% confidence interval (CI), 10.4 (3.7-29.6); P < 0.001; 5.7 (2.2-15.2); P < 0.001; and 3.7 (1.5-9.3); P = 0.005]. VLC n3-PUFAs significantly improved the performance of the noninvasive markers for advanced fibrosis - APRI, FIB-4, and NFS. Plasma concentrations of VLC SFAs and VLC n-3 PUFAs were further reduced in patients with HCC. Low concentrations of these FAs were also observed in relatives of patients with HCC and in subjects with the PNPLA3 rs738409 homozygous genotype. Low plasma concentrations of VLC n-3 PUFAs and VLC SFAs were strongly associated with advanced liver fibrosis and HCC in this population. Genetic factors were associated with low concentrations of these FAs as well. These results have implications in identifying those at risk for liver fibrosis progression to HCC and in screening this population for advanced fibrosis. They also prompt the evaluation of VLC n-3 PUFA or VLC SFA supplementation to prevent cirrhosis and HCC.

Association between PNPLA3 rs738409 polymorphism and nonalcoholic fatty liver disease: a systematic review and meta-analysis

BackgroundNon-alcoholic fatty liver disease (NAFLD) is a common disorder that is known to be the leading cause of chronic liver disease worldwide. This study aims to systematically review and meta-analyze the association between PNPLA3 rs738409 polymorphism and non-alcoholic fatty liver.MethodsFollowing a systematic review and meta-analysis method, articles without any time limitation, were extracted from SID, MagIran, IranDoc, Scopus, Embase, Web of Science (WoS), PubMed and ScienceDirect international databases. Random effects model was used for analysis, and heterogeneity of studies was investigated considering the I2 index and using Comprehensive Meta-Analysis software.ResultsThe odds ratio of CC genotype in patients with non-alcoholic fatty liver demonstrates the protective effect of CC genotype with the ratio of 0.52, whereas CG genotype presents an increasing effect of CG genotype with the ratio of 0.19, and GG genotype also showed an increasing effect of GG genotype with the ratio of 1.05. Moreover, CG + GG genotypes as a single group demostrated an odds rartio of 0.88.ConclusionThis meta-analysis highlights that people with CC genotype has 52% lower chance of developing non-alcoholic fatty liver disease, and those with CG genotype had 19% higher risk of developing non-alcoholic fatty liver. Those with GG genotype were 105% more likely to develop non-alcoholic fatty liver than others. Moreover, those present in a population with CG + GG genotypes were 88% more likely to have non-alcoholic fatty liver disease.

The Relationship Between Body Fat Distribution and Nonalcoholic Fatty Liver in Adults With Type 1 Diabetes.

Obesity, which is associated with nonalcoholic fatty liver (NAFL), has increased among people with type 1 diabetes. Therefore, we explored the associations between body fat distribution and NAFL in this population. This study included 121 adults with type 1 diabetes from the Finnish Diabetic Nephropathy (FinnDiane) Study for whom NAFL was determined by magnetic resonance imaging. Body composition was assessed by dual-energy X-ray absorptiometry. Genetic data concerning PNPLA3 rs738409 and TM6SF2 rs58542926 were available as a directly genotyped polymorphism. Associations between body fat distribution, waist-to-height ratio (WHtR), BMI, and NAFL were explored using logistic regression. A receiver operating characteristic (ROC) curve was used to determine the WHtR and BMI thresholds with the highest sensitivity and specificity to detect NAFL. Median age was 38.5 (33-43.7) years, duration of diabetes was 21.2 (17.9-28.4) years, 52.1% were women, and the prevalence of NAFL was 11.6%. After adjusting for sex, age, duration of diabetes, and PNPLA3 rs738409, the volume (P = 0.03) and percentage (P = 0.02) of visceral adipose tissue were associated with NAFL, whereas gynoid, appendicular, and total adipose tissues were not. The area under the curve between WHtR and NAFL was larger than BMI and NAFL (P = 0.04). The WHtR cutoff of 0.5 showed the highest sensitivity (86%) and specificity (55%), whereas the BMI of 26.6 kg/m2 showed 79% sensitivity and 57% specificity. Visceral adipose tissue is associated with NAFL in adults with type 1 diabetes, and WHtR may be considered when screening for NAFL in this population.

Secure and optimized detection of PNPLA3 rs738409 genotype by an improved PCR-restriction fragment length polymorphismmethod.

The PNPLA3reference single-nucleotide polymorphism rs738409 has been identified as a predisposing factor for nonalcoholic fatty liver disease. A simple method based on PCRandrestriction fragment length polymorphism (RFLP) analysis had been published to detect the nonpathogenic allelePNPLA3 rs738409variant. The presence of the pathogenic variant was deduced by the indigestibility of the corresponding PCR product with BtsCI recognizing the nonpathogenic allele. However, one cannot exclude that an enzymatic reaction does not occur for other, more trivial, reasons. For safe and secure detection of the pathogenic PNPLA3 rs738409, we have further developed the PCR-restriction fragment length polymorphism methodby adding a second restriction enzyme digest, clearly identifying the correct PNPLA3 alleles and in particular the pathogenic variant.

A genome-first approach to mortality and metabolic phenotypes in MTARC1 p.Ala165Thr (rs2642438) heterozygotes and homozygotes

A coding variant in MTARC1 (rs2642438; p.Ala165Thr) was recently associated with protection from cirrhosis in European individuals. However, its impact on overall and cause-specific mortality remained elusive. Using a genome-first approach, we explored a range of metabolic phenotypes and outcomes associated with MTARC1 p.Ala165Thr in the UKBiobank and the Penn-Medicine BioBank. MTARC1 p.Ala165Thr was significantly associated with higher triglycerides, lower total cholesterol, lower LDL-C, lower ApoB, lower HDL-C, lower ApoA-I and higher IGF-1. Per each minor allele, the risk of NAFLD was reduced by ~15%. The ALT-lowering and NAFLD-protective effect of MTARC1 p.Ala165Thr was amplified by obesity, diabetes mellitus and presence of PNPLA3 rs738409:G. In African-American and Black-British individuals, the allele frequency of MTARC1 p.Ala165Thr was lower, but carriers showed the same distinctive lipid phenotype. Importantly, MTARC1 p.Ala165Thr carriers did not show higher cardiovascular disease burden as evidenced by cardiac MRI and carotid ultrasound. In prospective analyses, the homozygous minor allele was associated with up to 39% lower rates of liver-related mortality, while no risk of increased overall or cardiovascular death could be observed. Strikingly, liver-related mortality was more than 50% reduced in diabetic participants or carriers of PNPLA3 rs738409:G. Together these data highlight MTARC1 as an important liver disease modifier that influences plasma lipids in an allele-dose-dependent manner without increasing cardiovascular outcomes. Our results point toward potential mechanisms and reveal a remarkable association with liver-related mortality calling for future studies exploring its therapeutic potential. This study was funded by the German Research Foundation (DFG).

The Effect of Genetic Polymorphism in Response to Body Weight Reduction in Japanese Patients with Nonalcoholic Fatty Liver Disease.

Background: weight loss as a result of lifestyle intervention is effective when treating non-alcoholic fatty liver disease (NAFLD). We estimated the effects of PNPLA3 rs738409 and HSD17B13 rs6834314 variants in response to diet therapy in Japanese patients with NAFLD. Methods: we analyzed the correlation between the change in liver stiffness and change in body weight in 140 patients administered diet therapy for 1-year, according to PNPLA3 and HSD17B13 genotypes. Results: the bodyweight (BW) reduction rate was greater in patients with the PNPLA3 genotype CC than CG and GG (p = 0.035). Change in liver stiffness measurement (LSM) was significantly associated with a change in BW in PNPLA3 CG/GG (r = 0.279/0.381), but not in PNPLA3 CC (p = 0.187). Change in LSM was correlated with change in BW only in patients with HSD17B13 AG/GG (r = 0.425), but not the AA genotype (p = 0.069). A multivariate analysis identified that a change in LSM was correlated with a change in BW in carriers of HSD17B13 AG/GG (B = 3.043, p = 0.032), but not HSD17B13 AA. The change in LSM of patients with a BW reduction of more than 7% (0.50) was significantly greater than that of patients with a BW reduction of less than 7% (0.83) (p = 0.038). Conclusions: in Japanese patients with NAFLD, HSD17B13 rs6834314 polymorphism is associated with the change in LSM by lifestyle intervention. The approach, including genetic assessments, may contribute to the establishment of appropriate therapeutic strategies to treat NAFLD.

Epidemiology and Disease Burden of Non-Alcoholic Steatohepatitis (NASH) in Greater China: A Systematic Review

Background: Non-Alcoholic steatohepatitis (NASH) is a progression of non-alcoholic fatty liver disease, leading to fibrosis, cirrhosis and hepatocellular carcinoma. The increasing burden of NASH has become a major concern of public health in greater China largely contributed by the rapid transition of lifestyle. The study aimed to characterize the epidemiology, disease burden, and treatment of NASH in greater China in order to better inform national disease management and delivery of health services. Methods: We conducted a systematic review searching four English databases (Web of Science, PubMed, Medline, and Cochrane Central) and three Chinese databases (CNKI, Wanfang, and VIP). We identified articles published from database inception to Oct 10, 2020 which reported NASH epidemiology, disease burden, and/or intervention in Chinese adults. The type of studies might include cross-sectional, cohort studies, randomized controlled trials and mathematical models. Exclusion criteria were studies for animal or cellular experiments, about population outside greater China, or with incomplete data. Findings: Of 44,115 articles retrieved, 33 were eligible for inclusion. Overall prevalence of NASH ranged from 2 ·4% to 6·1% in greater China, with a more substantial burden among males, the aged, and those in Hong Kong and Taiwan. Most NASH patients suffered from several comorbidities, including obesity, diabetes, and cardiovascular conditions. For non-obese subjects, PNPLA3 rs738409 G allele and haptoglobin 2-2 genotype drove the fibrosis progression in NASH. Increasingly prevalent cases of cirrhosis and hepatocellular carcinoma caused a higher NASH-related mortality. Compared with normal population, NASH patients experienced markedly poorer quality of life and heavier costs. Clinical trials of medication treatments specific for NASH are still ongoing. Interpretation: This is the first comprehensive overview of NASH among Chinese population that revealed an overwhelming impact of social and healthcare burden associated with the condition. Further high-quality studies are needed to improve the understanding and management of NASH in greater China. Funding: There was no funding source for this study. Declaration of Interests: We declare no competing interests.

A PDCD1 Role in the Genetic Predisposition to NAFLD-HCC?

Simple SummaryMany more people are dying each year from primary liver cancers arising in obesity-related fatty liver disease. Often these cancers are a consequence of fatty liver disease progression, with inflammation, scarring and cirrhosis. Less often, cancers develop in the presence of fat without cirrhosis. Evidence from animal models suggests the immune response to fat is important. We have explored genetic variations in candidate immunoregulatory genes. Our study of nearly one-thousand patients with fatty liver disease, comparing 391 with cancers to 594 without, indicates that genetic variation in a gene (PDCD1) that codes for the T cell receptor PD-1 may be important. Inherited variations that affect function of immunoregulatory proteins like PD-1 may underpin why some patients with fatty liver disease—whether they have cirrhosis or not—are more likely to develop liver cancer.Obesity and non-alcoholic fatty liver disease (NAFLD) are contributing to the global rise in deaths from hepatocellular carcinoma (HCC). The pathogenesis of NAFLD-HCC is not well understood. The severity of hepatic steatosis, steatohepatitis and fibrosis are key pathogenic mechanisms, but animal studies suggest altered immune responses are also involved. Genetic studies have so far highlighted a major role of gene variants promoting fat deposition in the liver (PNPLA3 rs738409; TM6SF2 rs58542926). Here, we have considered single-nucleotide polymorphisms (SNPs) in candidate immunoregulatory genes (MICA rs2596542; CD44 rs187115; PDCD1 rs7421861 and rs10204525), in 594 patients with NAFLD and 391 with NAFLD-HCC, from three European centres. Associations between age, body mass index, diabetes, cirrhosis and SNPs with HCC development were explored. PNPLA3 and TM6SF2 SNPs were associated with both progression to cirrhosis and NAFLD-HCC development, while PDCD1 SNPs were specifically associated with NAFLD-HCC risk, regardless of cirrhosis. PDCD1 rs7421861 was independently associated with NAFLD-HCC development, while PDCD1 rs10204525 acquired significance after adjusting for other risks, being most notable in the smaller numbers of women with NAFLD-HCC. The study highlights the potential impact of inter individual variation in immune tolerance induction in patients with NAFLD, both in the presence and absence of cirrhosis.

The FTO, PNPLA3 and TM6SF2 Gene Polymorphisms and Genetic Predisposition to NAFLD in Yakut Population

The aim of our research was to study the distribution of alleles and genotypes of the FTO rs9939609 SNP, the PNPLA3 rs738409 SNP, and the TM6SF2 rs58542926 SNP in the Yakut population. Methods and Results: A total of 85 DNA samples from the population were tested. An analysis of the frequency distribution of alleles and genotypes of the FTO rs9939609 SNP in the study group did not reveal significant differences. An analysis of the frequency distribution of alleles and genotypes of the PNPLA3 rs738409 SNP revealed that in men and women the G allele and the homozygous GG genotype prevailed. The results of the analysis of the frequency distribution of alleles and genotypes of the TM6SF2 rs58542926 SNP showed the predominance of individuals with the C allele (89% in men and 90% in women) with statistical significance in women. Conclusion: The further studies with a larger sample size are required to detect the features of the distribution of alleles and genotypes of the FTO rs9939609 SNP and the TM6SF2 rs58542926 SNP in that population.

Individualized Polygenic Risk Score Identifies NASH in the Eastern Asia Region: A Derivation and Validation Study.

INTRODUCTION:Strong evidence indicates that multiple genetic and environmental risk factors play a role in the pathogenesis of nonalcoholic steatohepatitis (NASH). We aimed to develop and validate a novel nomogram, incorporating both genetic and clinical factors, for predicting NASH.METHODS:A total of 1,070 Asian individuals with biopsy-confirmed nonalcoholic fatty liver disease (NAFLD) from 2 countries (China and South Korea) were recruited. The histological spectrum of NAFLD was classified according to the NASH clinical research network scoring system. The nomogram was developed in the Chinese training set (n = 402), and then, it was validated in both the Chinese internal validation set (n = 136) and the external Korean validation cohort (n = 532), respectively.RESULTS:Sex, metabolic syndrome, insulin resistance, serum aspartate aminotransferase levels, and PNPLA3 (rs738409) and HSD17B13 (rs72613567) genetic variants were strongly associated with NASH. Based on their regression coefficients, we developed a nomogram with good discriminatory ability (area under the receiver operating characteristic curve: 0.81, 95% confidence interval [CI] 0.77–0.85) and good calibration (Hosmer-Lemeshow test, P = 0.794) for identifying NASH. In the 2 validation cohorts, the nomogram showed high area under the receiver operating characteristic curves (internal validation set: 0.80, 95% CI 0.72–0.88; external validation cohort: 0.76, 95% CI 0.72–0.80) and good calibration.DISCUSSION:Our newly developed and externally validated nomogram, incorporating both genetic and clinical risk factors, may be conveniently used to predict NASH. Further validation studies in other ethnic groups are warranted to confirm its diagnostic utility to identify NASH, among patients with biopsy-proven NAFLD.

PNPLA3 and SERPINA1 Variants Are Associated with Severity of Fatty Liver Disease at First Referral to a Tertiary Center.

Single nucleotide polymorphisms (SNPs), including PNPLA3 rs738409 and SERPINA1 rs17580, have been identified as risk modifiers in the progression fatty liver disease (alcoholic (ALD) or non-alcoholic (NAFLD)). While PNPLA3 has been studied in various settings, the value of both SNPs has so far not been addressed in a real-world cohort of subjects referred for a diagnostic work-up of liver disease. Thus, liver disease severity was assessed in 1257 consecutive patients with suspected ALD or NAFLD at the time of referral to a tertiary center. Advanced chronic liver disease (ACLD) was present in 309 (24.6%) patients and clinically significant portal hypertension (CSPH) was present in 185 (14.7%) patients. The PNPLA3 G-allele was independently associated with a higher liver stiffness measurement (LSM; adjusted B: 2.707 (1.435–3.979), p < 0.001), and higher odds of ACLD (adjusted odds ratio (aOR): 1.971 (1.448–2.681), p < 0.001) and CSPH (aOR: 1.685 (1.180–2.406), p = 0.004). While the SERPINA1 Z-allele was not associated with a higher LSM or the presence of ACLD, it was independently associated with higher odds of CSPH (aOR: 2.122 (1.067–4.218), p = 0.032). Associations of the PNPLA3 G-allele and the SERPINA1 Z-allele with CSPH were maintained independently of each other. The presence of both risk variants further increased the likelihood of ACLD and CSPH.

The role of PNPLA3 and TM6SF2 polymorphisms on liver fibrosis and metabolic abnormalities in Brazilian patients with chronic hepatitis C

BackgroundDespite the growing body of knowledge about TM6SF2 and PNPLA3 polymorphisms in non-alcoholic fatty liver disease, their influence in the spectrum of HCV liver disease is not yet fully defined. Besides that, admixed populations, such as Brazilians, were not included in most of the studies.MethodsThis cross-sectional study enrolled 365 treatment-naïve patients with HCV and 134 healthy individuals. TM6SF2 (rs58542926 c.499C > T) and PNPLA3 (rs738409 c.444C > G) polymorphisms were evaluated regarding their association with clinical and laboratory data, histological liver steatosis and fibrosis, and with components of the metabolic syndrome.ResultsIn HCV subjects, the frequencies of TM6SF2 CC and CT + TT were 89% and 11%, while PNPLA3 frequencies of CC and CG + GG were 51.4% and 48.6%. In the univariate logistic regression analysis, the TM6SF2 CT + TT genotype in HCV was associated with significant liver fibrosis (p = 0.047; OR 1.953; 95% CI 1.009–3.788). In comparison to the CT + TT genotype, the TM6SF2 CC genotype in HCV was associated with older age (p = 0.002), higher frequency of arterial hypertension (p = 0.032), obesity (p = 0.030), metabolic syndrome (p = 0.014) and lower total cholesterol levels (p = 0.036). The PNPLA3 GG subjects had lower body mass index than CG/ CC individuals (p = 0.047). None of the polymorphisms, or their combinations, was independently associated with hepatic steatosis or fibrosis. On the other hand, older age, lower serum levels of total cholesterol, and higher serum levels of alanine aminotransferase and alkaline phosphatase were associated with liver fibrosis in the multivariate logistic regression analysis.ConclusionIn this evaluation of an admixed HCV population, neither TM6SF2 nor PNPLA3 polymorphisms were independently associated with hepatic steatosis or fibrosis. Other factors seem more influential than these specific polymorphisms in isolation. More studies are warranted to clarify the role of the TM6SF2 and PNPLA3 polymorphisms in Brazilians with HCV.

Associations of Hydroxysteroid 17-beta Dehydrogenase 13 Variants with Liver Histology in Chinese Patients with Metabolic-associated Fatty Liver Disease

Background and AimsIn Europeans, variants in the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) gene impact liver histology in metabolic-associated fatty liver disease (MAFLD). The impact of these variants in ethnic Chinese is unknown. The aim of this study was to investigate the potential associations in Chinese patients.MethodsIn total, 427 Han Chinese with biopsy-confirmed MAFLD were enrolled. Two single nucleotide polymorphisms in HSD17B13 were genotyped: rs72613567 and rs6531975. Logistic regression was used to test the association between the single nucleotide polymorphisms and liver histology.ResultsIn our cohort, the minor allele TA of the rs72613567 variant was related to an increased risk of fibrosis [odds ratio (OR): 2.93 (1.20–7.17), p=0.019 for the additive model; OR: 3.32 (1.39–7.91), p=0.007 for the recessive model], representing an inverse association as compared to the results from European cohorts. In contrast, we observed a protective effect on fibrosis for the minor A allele carriers of the HSD17B13 rs6531975 variant [OR: 0.48 (0.24–0.98), p=0.043 for the additive model; OR: 0.62 (0.40–0.94), p=0.025 for the dominant model]. HSD17B13 variants were only associated with fibrosis but no other histological features. Furthermore, HSD17B13 rs6531975 modulated the effect of PNPLA3 rs738409 on hepatic steatosis.ConclusionsHSD17B13 rs72613567 is a risk variant for fibrosis in a Han Chinese MAFLD population but with a different direction for allelic association to that seen in Europeans. These data exemplify the need for studying diverse populations in genetic studies in order to fine map genome-wide association studies signals.