TM6SF2 Rs58542926 Research Articles

Human induced pluripotent stem cell based hepatic-modeling of lipid metabolism associated TM6SF2 E167K variant.

TM6SF2 rs58542926 (E167K) is related to increased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD). Conflicting mouse study results highlight the need for a human model to understand this mutation's impact. This study aims to create and characterize a reliable human in vitro model to mimic the effects of the TM6SF2-E167K mutation for future studies. We used gene editing on human human-induced pluripotent stem cells (iPSC) from a healthy individual to create cells with the TM6SF2-E167K mutation. After hepatocyte directed differentiation, we observed decreased TM6SF2 protein expression, increased intracellular lipid droplets and total cholesterol in addition to reduced VLDL secretion. Transcriptomics revealed upregulation of genes involved in lipid, fatty acid, and cholesterol transport, flux, and oxidation. Global lipidomics showed increased lipid classes associated with ER stress, mitochondrial dysfunction, apoptosis, and lipid metabolism. Additionally, the TM6SF2-E167K mutation conferred a pro-inflammatory phenotype with signs of mitochondria and ER stress. Importantly, by facilitating protein folding within the ER of hepatocytes carrying TM6SF2-E167K mutation, VLDL secretion and ER stress markers improved. Our findings indicate that induced hepatocytes generated from iPSCs carrying the TM6SF2-E167K recapitulate the effects observed in human hepatocytes from individuals with the TM6SF2 mutation. This study characterizes an in vitro model that can be used as a platform to identify potential clinical targets and highlights the therapeutic potential of targeting protein misfolding to alleviate ER stress and mitigate the detrimental effects of the TM6SF2-E167K mutation on hepatic lipid metabolism.

Does Genetic Variation in PNPLA3, TM6SF2 and HSD17B13 have a Role in the Development or Prognosis of Hepatocellular Carcinoma in Turkish Patients with Hepatitis B?

Progression to hepatocellular carcinoma (HCC) is restricted by viral suppression in chronic hepatitis B (CHB); however, some patients still progress despite antiviral therapy. Presence of single nucleotide polymorphisms (SNPs) such as PNPLA3 rs738409 and TM6SF2 rs58542926 are associated with the development and progression of steatotic liver disease to HCC, whereas a splice variant in HSD17B13 rs72613567:TA has been shown to be protective. We investigated the role of these SNPs in the development or prognosis of HCC in pure CHB etiology, in the absence of hepatic steatosis, remains unknown. We analysed PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 SNPs in a prospectively recruited cohort (n=323) consisting of healthy controls, CHB and CHB-HCC patients without hepatic steatosis. SNPs were determined by PCR analysis and associations for the alleles and genotypes were investigated using adjusted-logistic regression analyses. The overall survival (OS) data were collected from CHB-HCC patients for survival analysis. The genotype and allelic distribution of PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 were similar between healthy controls, CHB, and CHB-HCC groups. No genotype, allele or haplotype analysis was found to be associated with increased risk for CHB-HCC. Survival analysis revealed no genotype or allele to be associated with OS in patients with CHB-HCC. We could not demonstrate any association of PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 with the development or prognosis of CHB-HCC, supporting the initial hypothesis that they should be considered specific hotspots for liver diseases characterized with hepatic steatosis.

Use of PNPLA3, TM6SF2, and HSD17B13 for detection of fibrosis in MASLD in the general population

BackgroundGenetic testing can be used to evaluate disease risk. We evaluated if the use of three Single Nucleotide Polymorphisms (SNPs), alone or combined into a genetic risk score (GRS), can aid identify significant fibrosis in subjects with metabolic dysfunction-associated steatotic liver disease (MASLD). MethodsWe assessed three known risk variants: PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567. The study included 414 adult individuals invited from the Danish population, who were defined as at-risk of MASLD due to elevated ALT and body mass index (BMI) >25 kg/m2. Participants were assessed clinically and by the Fibrosis-4 (FIB-4) index and Fibroscan. ResultsIn total, 17 participants (4.1 %) had alcohol-related liver disease, 79 (19.1 %) had no evidence of liver disease, and four (1.0 %) were diagnosed with other liver diseases, including malignant disease. The remaining 314 participants (75.8 %) were diagnosed with MASLD. Of the 27 who underwent a liver biopsy for suspected fibrosis, 15 had significant fibrosis (≥F2) and 12 had no/mild fibrosis (F0/F1). The GRS was not associated with significant fibrosis (p = 0.09) but PNPLA3 was with an odds ratio of 6.75 (95 % CI 1.29 – 50.7; p = 0.039) risk allele CG/GG versus CC. The diagnostic accuracy of PNPLA3 combined with an increased Fib-4 (>1.3) was excellent for detecting significant fibrosis with a sensitivity of 1.00 (95 % CI 0.72–1.00), but the specificity was no better than for FIB-4 alone. ConclusionsThis study found no evidence to support the use of GRS for diagnosing significant fibrosis in MASLD. However, the combination of PNPLA3 and Fib-4 increased sensitivity considerably. In addition, ALT remains a useful tool for screening diagnosing other liver diseases than MASLD.

Liver Fibrosis Assessed Via Noninvasive Tests Is Associated With Incident Heart Failure in a General Population Cohort

The aim of this study was to determine whether liver fibrosis is associated with heart failure in a general population cohort, and if genetic polymorphisms (PNPLA3 rs738409; TM6SF2 rs58542926), linked to increased risk of liver fibrosis and decreased risk of coronary artery disease, modify this association. Using UK Biobank data, we prospectively examined the relationship between noninvasive fibrosis markers (nonalcoholic fatty liver disease [NAFLD] fibrosis score [NFS], Fibrosis-4 [FIB-4] and aspartate transaminase [AST] to platelet ratio index [APRI]) and incident hospitalization/death from heart failure (n= 413,860). Cox-regression estimated hazard ratios (HRs) for incident heart failure. Effects of PNPLA3 and TM6SF2 on the association between liver fibrosis and heart failure were estimated by stratifying for genotype and testing for an interaction between genotype and liver fibrosis using a likelihood ratio test. A total of 12,527 incident cases of heart failure occurred over a median of 10.7 years. Liver fibrosis was associated with an increased risk of hospitalization or death from heart failure (multivariable adjusted high-risk NFS score HR, 1.59; 95% confidence interval [CI],1.47-1.76; P < .0001; FIB-4 HR, 1.69; 95% CI, 1.55-1.84; P < .0001; APRI HR, 1.85; 95% CI, 1.56-2.19; P < .0001; combined fibrosis scores HR, 1.90; 95% CI, 1.44-2.49; P < .0001). These associations persisted for people with metabolic dysfunction-associated steatotic liver disease (MASLD), MASLD with alcohol consumption (Met-ALD), and harmful alcohol consumption. PNPLA3 rs738409 GG and TM6SF2 rs58542926 TT did not attenuate the positive association between fibrosis markers and heart failure. For PNPLA3, a statistically significant interaction was found between PNPLA3 rs738409, FIB-4, APRI score, and heart failure. In the general population, serum markers of liver fibrosis are associated with increased hospitalization/death from heart failure. Genetic polymorphisms associated with liver fibrosis were not positively associated with elevated heart failure risk.

Differential Effects of Genetic Polymorphism on Comorbid Disease in Metabolic Dysfunction–Associated Steatotic Liver Disease

PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 have been associated with an increased risk of liver-related events (LREs) in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). In this study, we investigated the combined effects of these variants on LREs. The longitudinal multicenter cohort study enrolled 1178 patients with biopsy-proven MASLD. We calculated the genetic risk of hepatic fibrosis and LRE according to the impact of these variants. Patients with genetic fibrosis scores of 2, 3, and 4 or 5 were at greater risk than patients with scores of 0 or 1, with odds ratios of 2.45 (95% CI, 1.27-4.74), 2.14 (95% CI, 1.17-3.94), and 2.54 (95% CI, 1.35-4.77), respectively. Multivariate analysis revealed that PNPLA3 and TM6SF2, but not HSD17B13, were associated significantly with LRE development. The hazard ratio of the genetic high-risk group for LRE was 1.91 (95% CI, 1.20-3.04). The higher risk of LRE development in the genetic high-risk group also was seen in patients with F ≥ 3 or Fibrosis-4 index > 2.67. The hazard ratios of the genetic high-risk group for LRE were greater in patients without obesity, without diabetes, and of younger age compared with patients with obesity, with diabetes, or of older age, respectively. This combination of MASLD-related genetic variants is useful for predicting LREs in Japanese patients with MASLD. The genetic risk according to these variants is useful for LRE risk assessment, especially in patients without metabolic risk factors or in younger patients in Japan.

Relevance of PNPLA3, TM6SF2, HSD17B13, and GCKR Variants to MASLD Severity in an Egyptian Population.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a frequent clinical condition globally. Single nucleotide polymorphisms (SNPs) associated with NAFLD have been proposed in the literature and based on bioinformatic screening. The association between NAFLD and genetic variants in Egyptians is still unclear. Hence, we sought to investigate the association of some genetic variants with NAFLD in Egyptians. Egyptians have been categorized into either the MASLD group (n = 205) or the healthy control group (n = 187). The severity of hepatic steatosis and liver fibrosis was assessed by a Fibroscan device. TaqMan-based genotyping assays were employed to explore the association of selected SNPs with MASLD. PNPLA3 rs738409 C>G variant is associated with the presence of MASLD with liver fibrosis, the severity of both hepatic steatosis and liver fibrosis, increased systolic and diastolic blood pressure and increased alanine aminotransferase (all p < 0.05), while the TM6SF2 rs58542926 C>T, HSD17B13 rs9992651 G>A, and GCKR rs1260326 T>C variants were not (all p > 0.05). The TM6SF2 rs58542926 T allele is associated with increased fasting blood glucose and a decreased waist circumference. The GCKR rs1260326 C allele is associated with decreased aspartate transaminase and diastolic blood pressure (all p < 0.05). Only after adjusting for the risk factors (age, sex, BMI, WC, HDL, TG, diabetes mellitus, and hypertension) F2 liver fibrosis score is negatively correlated with the HSD17B13 rs9992651 GA genotype. This study offers evidence for the association of the PNPLA3 rs738409 C>G variant with MASLD among Egyptians and for the association of the PNPLA3 rs738409 G allele, the TM6SF2 rs58542926 T allele, and the GCKR rs1260326 C allele with some parameters of cardiometabolic criteria.

Liver Biopsy Handling of Metabolic-Associated Fatty Liver Disease (MAFLD): the Children's Hospital of Eastern Ontario grossing protocol.

Metabolic-(non-alcoholic) associated fatty liver disease (MAFLD/NAFLD) has increasingly become a worldwide epidemic. It has been suggested that renaming NAFLD to MAFLD is critical in identifying patients with advanced fibrosis and poor cardiovascular outcomes. There are concerns that the progression to non-alcoholic steatohepatitis (NASH) may become a constant drive in the future healthcare of children and adolescents. There is a necessity to tackle the emerging risk factors for NASH-associated hepatocellular carcinoma (HCC). In this narrative review, we present the current protocol of liver biopsy separated between pre-analytical, analytical, and post-analytical handling. Genetic association investigations have identified single nucleotide polymorphisms implicated in the progression of MAFLD-HCC, many of which seem to belong to the lipid metabolism pathways. PNPLA3 rs738409 variant, TM6SF2 rs58542926 variant, MBOAT7 rs641738 variant, and GCKR variants seem to be significantly associated with NAFLD disease susceptibility. In disclosing the current comprehensive protocol performed at the Children's Hospital of Eastern Ontario, Ottawa, ON, Canada, we support the most recent Kulkarni-Sarin's pledge to rename NAFLD to MAFLD. Grossing of the liver biopsy is key to identifying histologic, immunophenotypical, and ultrastructure data and properly preserving tissue for molecular genomics data.

Impact of genetic polymorphismon personalized diet and exercise program for steatotic liver disease.

The effectsof genetic polymorphism on a personalized diet and exercise program for steatotic liver disease (SLD) are still unclear. Participants of this retrospective cohort study were 203 Japanese patients with SLD diagnosed by abdominal ultrasonography. All of them were introduced the personalized diet and exercise treatment. A diet of 25-30kcal/kg multiplied by ideal body weight (BW) daily and aerobic and resistance exercise (exercise intensity of 4-5 metabolic equivalents daily, respectively) were performed for 6days. Treatment efficacy was evaluated in terms of the rate of decrease of liver function tests, glycolipid metabolism markers, physical findings, image findings, and cardiovascular disease (CVD) risk score at 6months compared with baseline. Furthermore, the impact of genetic polymorphism was also investigated. At 6months compared with baseline, liver function tests (AST, ALT, γGTP), glycolipid metabolism markers (hemoglobin A1c, triglycerides [TG], low-density lipoprotein cholesterol), physical findings (BW, body mass index), image finding (liver stiffness measurement), and CVD risk score (Suita score) improved significantly. There was no significant difference in treatment efficacy, except for the rates of decrease of TG, according to genotype PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs6834314. The rates of decrease of TG with TM6SF2 CT were significantly higher than those with CC or TT, and the rates of TG with HSD17B13 AA were significantly higher than those with AG by multiple comparisons. Personalized diet and exercise program for SLD improved liver function tests, physical findings, glycolipid metabolism markers, and CVD risk score. Genetic polymorphism might partially affect treatment efficacy. Further studies should be performed to develop an individualized program for SLD, considering genetic polymorphism.

Genetic Predictors of Comorbid Course of COVID-19 and MAFLD: A Comprehensive Analysis.

Metabolic-associated fatty liver disease (MAFLD) and its potential impact on the severity of COVID-19 have gained significant attention during the pandemic. This review aimed to explore the genetic determinants associated with MAFLD, previously recognized as non-alcoholic fatty liver disease (NAFLD), and their potential influence on COVID-19 outcomes. Various genetic polymorphisms, including PNPLA3 (rs738409), GCKR (rs780094), TM6SF2 (rs58542926), and LYPLAL1 (rs12137855), have been investigated in relation to MAFLD susceptibility and progression. Genome-wide association studies and meta-analyses have revealed associations between these genetic variants and MAFLD risk, as well as their effects on lipid metabolism, glucose regulation, and liver function. Furthermore, emerging evidence suggests a possible connection between these MAFLD-associated polymorphisms and the severity of COVID-19. Studies exploring the association between indicated genetic variants and COVID-19 outcomes have shown conflicting results. Some studies observed a potential protective effect of certain variants against severe COVID-19, while others reported no significant associations. This review highlights the importance of understanding the genetic determinants of MAFLD and its potential implications for COVID-19 outcomes. Further research is needed to elucidate the precise mechanisms linking these genetic variants to disease severity and to develop gene profiling tools for the early prediction of COVID-19 outcomes. If confirmed as determinants of disease severity, these genetic polymorphisms could aid in the identification of high-risk individuals and in improving the management of COVID-19.

Genetic and Metabolic Characteristics of Lean Nonalcoholic Fatty Liver Disease in a Korean Health Examinee Cohort.

The pathophysiology of lean nonalcoholic fatty liver disease (NAFLD) is unclear but has been shown to be associated with more diverse pathogenic mechanisms than that of obese NAFLD. We investigated the characteristics of genetic or metabolic lean NAFLD in a health checkup cohort. This retrospective cross-sectional study analyzed single nucleotide polymorphism data for 6,939 health examinees. Lean individuals were categorized according to a body mass index cutoff of 23 kg/m2. Single nucleotide polymorphisms were analyzed using genotyping arrays. The prevalence of lean NAFLD was 21.6% among all participants with NAFLD, and the proportion of lean NAFLD was 18.5% among lean participants. The prevalence of metabolic syndrome and diabetes among lean patients with NAFLD was 12.4% and 10.4%, respectively. Lean NAFLD appeared to be metabolic-associated in approximately 20.1% of patients. The homozygous minor allele (GG) of PNPLA3 (rs738409) and heterozygous minor alleles (CT, TT) of TM6SF2 (rs58542926) were associated with lean NAFLD. However, the prevalence of fatty liver was not associated with the genetic variants MBOAT7 (rs641738), HSD17B13 (rs72613567), MARC1 (rs2642438), or AGXT2 (rs2291702) in lean individuals. Lean NAFLD appeared to be associated with PNPLA3 or TM6SF2 genetic variation in approximately 32.1% of cases. Multivariate risk factor analysis showed that metabolic risk factors, genetic risk variants, and waist circumference were independent risk factors for lean NAFLD. In a considerable number of patients, lean NAFLD did not appear to be associated with known genetic or metabolic risk factors. Further studies are required to investigate additional risk factors and gain a more comprehensive understanding of lean NAFLD.

TM6SF2 rs58542926 is linked to thrombocytopenia-related advanced hepatic fibrosis in Egyptian patients with chronic hepatitis C

TM6SF2 rs58542926 is linked to thrombocytopenia-related advanced hepatic fibrosis in Egyptian patients with chronic hepatitis C

Metabolic disorders induced by PNPLA3 and TM6SF2 gene variants affect chronic kidney disease in patients infected with non-genotype 3 hepatitis C virus

BackgroundPatients with chronic hepatitis C virus (HCV) infections differ in their risk for metabolic disorders and chronic kidney disease (CKD). The aim of this study was to investigate the effect of metabolic disorders induced by genetic factors on CKD in HCV-infected patients.MethodsPatients with chronic non-genotype 3 HCV infection with or without CKD were examined. PNPLA3 and TM6SF2 variants were determined using high-throughput sequencing. The relationships of variants and different combinations with metabolic disorders were analyzed in CKD patients. Univariate and multivariate analyses were used to identify factors associated with CKD.ResultsThere were 1022 patients with chronic HCV infection, 226 with CKD and 796 without CKD. The CKD group had more severe metabolic disorders, and also had higher prevalences of liver steatosis, the PNPLA3 rs738409 non-CC genotype, and the TM6SF2 rs58542926 CC genotype (all P < 0.05). Relative to patients with the PNPLA3 rs738409 CC genotype, patients with the non-CC genotype had a significantly decreased eGFR and a greater prevalence of advanced CKD (CKD G4-5). Patients with the TM6SF2 rs58542926 CC genotype had a lower eGFR and a higher prevalence of CKD G4-5 than those with the non-CC genotype. Multivariable analysis indicated that multiple metabolic abnormalities, including liver steatosis and the PNPLA3 rs738409 C > G variant, increased the risk of CKD, but the TM6SF2 rs58542926 C > T variant decreased the risk of CKD.ConclusionSpecific PNPLA3 rs738409 and TM6SF2 rs58542926 variants are independent risk factors for CKD in patients with chronic HCV infections and are associated with the severity of renal injury.

Effects of TM6SF2 rs58542926 polymorphism on hepatocellular lipids and insulin resistance in early type 2 diabetes

Background and aimsIncreased hepatocellular lipid content (HCL) is linked to insulin resistance, risk of type 2 diabetes and related complications. Conversely, a single-nucleotide polymorphism (TM6SF2EK; rs58542926) in the transmembrane 6 superfamily member 2-gene has been associated with nonalcoholic fatty liver disease (NAFLD), but lower cardiovascular risk. This case-control study tested the role of this polymorphism for tissue-specific insulin sensitivity during early course of diabetes. Methods and resultsMales with recent-onset type 2 diabetes with (TM6SF2EK: n = 16) or without (TM6SF2EE: n = 16) the heterozygous TM6SF2-polymorphism of similar age and body mass index, underwent Botnia-clamps with [6,6-2H2]glucose to measure whole-body-, hepatic- and adipose tissue-insulin sensitivity. HCL was assessed with 1H-magnetic-resonance-spectroscopy. A subset of both groups (n = 24) was re-evaluated after 5 years. Despite doubled HCL, TM6SF2EK had similar hepatic- and adipose tissue-insulin sensitivity and 27% higher whole-body-insulin sensitivity than TM6SF2EE. After 5 years, whole-body-insulin sensitivity, HCL were similar between groups, while adipose tissue-insulin sensitivity decreased by 87% and 55% within both groups and circulating triacylglycerol increased in TM6SF2EE only. ConclusionsThe TM6SF2-polymorphism rs58542926 dissociates HCL from insulin resistance in recent-onset type 2 diabetes, which is attenuated by disease duration. This suggests that diabetes-related metabolic alterations dominate over effects of the TM6SF2-polymorphism during early course of diabetes and NAFLD.

THU-451 - Effect of PNPLA3 (rs738409 C > G) and TM6SF2 (rs58542926 C > T) polymorphisms on the prognosis of non-alcoholic fatty liver disease (NAFLD) in patients with type-2 Diabetes Mellitus

THU-451 - Effect of PNPLA3 (rs738409 C > G) and TM6SF2 (rs58542926 C > T) polymorphisms on the prognosis of non-alcoholic fatty liver disease (NAFLD) in patients with type-2 Diabetes Mellitus

Genetic variation and elevated liver enzymes during childhood, adolescence and early adulthood.

Genetic factors influence the risk of fatty liver disease (FLD) in adults. The aim of this study was to test if, and when, genetic risk factors known to affect FLD in adults begin to exert their deleterious effects during childhood, adolescence and early adulthood. We included up to 4018 British children and adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort. Three genetic variants known to associate robustly with FLD in adults (PNPLA3 rs738409, TM6SF2 rs58542926 and HSD17B13 rs72613567) were tested for association with plasma levels of alanine transaminase (ALT) and aspartate transaminase (AST) during childhood (mean age: 9.9 years), early adolescence (15.5 years), late adolescence (17.8 years), and early adulthood (24.5 years). We also tested the associations of a 17-variant score and whole-genome polygenic risk scores (PRS) derived from associations in adults with plasma ALT and AST at the same four time points. Associations with elastography-derived liver steatosis and fibrosis were tested in early adulthood. Genetic risk factors for FLD (individually, combined into a 3-variant score, a 17-variant score and as a genome-wide PRS), were associated with higher liver enzymes, beginning in childhood and throughout adolescence and early adulthood. The ALT-increasing effects of the genetic risk variants became larger with increasing age. The ALT-PRS was associated with liver steatosis in early adulthood. No genetic associations with fibrosis were observed. Genetic factors that promote FLD in adults associate with elevated liver enzymes already during childhood, and their effects get amplified with increasing age.

Characteristics and long-term mortality of patients with non-MAFLD hepatic steatosis

A cluster of hepatic steatosis without metabolic abnormalities has been excluded by the MAFLD definition, referred to as non-MAFLD steatosis. We aimed to characterize the non-MAFLD steatosis. We included 16,308 individuals from the UK Biobank who had magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) to describe the clinical and genetic features of non-MAFLD steatosis in a cross-sectional design, and 14,797 individuals of the NHANES III who underwent abdominal ultrasonography at baseline to assess the long-term mortality of non-MAFLD steatosis in a prospective cohort design. Of 16,308 individuals in the UK Biobank, 2747 fatty liver disease (FLD) cases (2604 MAFLD and 143 non-MAFLD) and 3007 healthy controls (without metabolic dysfunctions) were identified. The mean PDFF (10.65 vs. 9.00) and the proportion of advanced fibrosis (fibrosis-4 index > 2.67, 1.27% vs. 1.40%) were comparable between MAFLD and non-MAFLD steatosis. Non-MAFLD steatosis has the highest minor allele frequency of PNPLA3 rs738409, TM6SF2 rs58542926, and GCKR rs1260326 in contrast to the other two groups. The genetic risk score calculated by PNPLA3, TM6SF2, and GCKR has a certain predictive ability for non-MAFLD steatosis (AUROC = 0.69). NHANES III population showed that compared to healthy individuals, the adjusted hazard ratio of non-MAFLD steatosis increased by 1.52 (95% confidence interval: 1.21-1.91) and 1.78 (95% confidence interval: 1.03-3.07) for all-cause and heart disease-related mortality, respectively. Non-MAFLD steatosis has comparable degrees of hepatic steatosis and fibrosis to MAFLD and increases the risk of mortality. Genetic predisposition highly contributes to the risk of non-MAFLD steatosis.

Genetic variants in HFE are associated with non-alcoholic fatty liver disease in lean individuals

Background & AimsAround 20% of patients with non-alcoholic fatty liver disease (NAFLD) are lean. Increasing evidence suggests that lean NAFLD is a unique subtype of the disease. We aimed to explore the metabolic profile, genetic basis, causal risk factors, and clinical sequelae underlying lean NAFLD. MethodsNAFLD was diagnosed by whole liver proton density fat fraction ≥5%. Whole liver proton density fat fraction and hepatic iron were quantified using magnetic resonance imaging in the UK Biobank. Individuals in this study were stratified according to the World Health Organization criteria of obesity, into lean, overweight, and obese. Mediation analysis, Mendelian randomisation analysis, and Bayesian networks were used to identify a risk factor or a clinical sequela of lean/obese NAFLD. ResultsLean NAFLD manifested a distinct metabolic profile, featured by elevated hepatic iron and fasting glucose. Four loci, namely, HFE rs1800562, SLC17A3-SLC17A2-TRIM38 rs9348697, PNPLA3 rs738409, and TM6SF2 rs58542926, were associated with lean NAFLD (p <5 × 10-8). HFE rs1800562 was specifically associated with lean NAFLD and demonstrated a significant mediation effect through elevating hepatic iron. Type 2 diabetes was the most pronounced clinical sequela of lean NAFLD, followed by liver cirrhosis. ConclusionsOur study suggested that HFE plays a potential steatogenic role rather than regulating iron homoeostasis in patients with lean NAFLD. The increased liver iron deposition is associated with lean NAFLD, whereas obese NAFLD is not related to hepatic iron. The clinical management of patients with lean NAFLD shall be concerned with the prevention and treatment of type 2 diabetes and liver cirrhosis. Impact and implicationsLean NAFLD has a distinct natural history from obese NAFLD. This study underscored liver iron content and the genetic variant of the iron homoeostasis gene HFE as major risks of lean NAFLD, in addition to the unique metabolic profile. The development of type 2 diabetes or liver cirrhosis shall be closely monitored and prevented in patients with lean NAFLD.

Association of MAFLD with end-stage kidney disease: a prospective study of 337,783 UK Biobank participants.

Metabolic dysfunction-associated fatty liver (MAFLD) has been found to be associated with the prevalence of chronic kidney disease (CKD). However, it is unknown whether MAFLD is associated with CKD development and the incidence of end-stage kidney disease (ESKD). We aimed to clarify the association between MAFLD and incident ESKD in the prospective UK Biobank cohort. We analyzed the data of 337,783 UK Biobank participants and relative risks for the ESKD were calculated by using the Cox regression analysis. Among 337,783 participants over a median duration of 12.8years follow-up, a total of 618 ESKD cases were diagnosed. Participants with MAFLD were twice likely to develop ESKD (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.68-2.46, p < 0.001). The association of MAFLD with ESKD risk remained significant in both non-CKD and CKD participants. Our results also showed that there were graded associations between liver fibrosis scores and the risk of ESKD in MAFLD cases. Compared to non-MAFLD individuals, the adjusted HRs for incident ESKD in MAFLD patients with increasing levels of NAFLD fibrosis score were 1.23 (95% CI 0.96-1.58), 2.45 (1.98-3.03) and 7.67 (5.48-10.73), respectively. Furthermore, the risking alleles of PNPLA3 rs738409, TM6SF2 rs58542926, GCKR rs1260326 and MBOAT7 rs641738 amplified the MAFLD effect on ESKD risk. In conclusion, MAFLD is associated with incident ESKD. MAFLD may help identify the subjects at high risk of ESKD development and MAFLD interventions should be encouraged to slow down CKD progression.

Association of PNPLA3 (rs738409) & TM6SF2 (rs58542926) and ATG16L1 (rs2241880) genetic variants with susceptibility to hepatocellular carcinoma in a group of Egyptian patients with HCV-induced liver cirrhosis

Association of PNPLA3 (rs738409) & TM6SF2 (rs58542926) and ATG16L1 (rs2241880) genetic variants with susceptibility to hepatocellular carcinoma in a group of Egyptian patients with HCV-induced liver cirrhosis

Association of PNPLA3 rs738409 and TM6SF2 rs58542926 Polymorphisms with Non-alcoholic Fatty Liver Disease in the Iranian Population

Background: Non-alcoholic fatty liver disease (NAFLD) is a burgeoning health problem worldwide. Genetic predisposition increases susceptibility to NAFLD. The PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphisms are genetic risk factors for NAFLD. Objectives: This study aimed to investigate the association of rs738409 and rs58542926 polymorphisms with NAFLD among the Iranian population in two groups: (1) Population-based NAFLD (PB-NAFLD), and (2) clinic-based NAFLD (CB-NAFLD). Methods: This case-control study included a group of healthy individuals without NAFLD as the control group and two case groups, PB-NAFLD and CB-NAFLD. All individuals underwent clinical and laboratory assessments and were also diagnosed using ultrasonography. Genotyping for rs738409 and rs58542926 polymorphisms was carried out by the PCR-RFLP method. Results: A total of 110 control, 108 PB-NAFLD, and 73 CB-NAFLD individuals were included in the study. The distribution of rs738409 GG+CG in the PB-NAFLD was 39.8% while it was 52.7% in the control group (P = 0.06, OR = 0.59). The distribution of rs738409 GG in the CB-NAFLD was 19.2%, while it was 8.2% in the control group (P = 0.04, OR = 2.66). The distribution of rs58542926 genotypes was not significantly different between the NAFLD and control groups. In multivariate analysis, metabolic syndrome (OR = 2.85) and BMI &gt; 25 (OR = 3.32) were independent determinants of NAFLD in the PB-NAFLD group, and BMI &gt; 25 (OR = 7.15) was an independent determinant of NAFLD in the CB-NAFLD group. Conclusions: In this study, the PNPLA3 rs738409 polymorphism was associated with NAFLD in the CB-NAFLD cohort; however, the same was not observed for the PB-NAFLD cohort. The TM6SF2 rs58542926 polymorphism was not associated with NAFLD in the Iranian population.