Biopsy-proven Nonalcoholic Fatty Liver Disease Research Articles

Expression and localization of HSD17B13 along mouse urinary tract.

17β-hydroxysteroid dehydrogenase-13 (HSD17B13), a newly identified lipid droplet-associated protein, plays an important role in the development of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). Emerging evidence demonstrates that NASH is an independent risk factor for chronic kidney disease (CKD), which is frequently accompanied by renal lipid accumulation. In addition, the HSD17B13 rs72613567 variant is associated with lower levels of albuminuria in patients with biopsy-proven NAFLD. At present, the role of HSD17B13 in lipid accumulation in the kidney is unclear. ​This study utilized bioinformatic and immunostaining approaches to examine the expression and localization of HSD17B13 along mouse urinary tract. We found that HSD17B13 is constitutively expressed in the kidney, ureter and urinary bladder. Our findings reveal for the first time the precise localization of HSD17B13 in mouse urinary system, providing a basis for further studying the pathogenesis of HSD17B13 in various renal and urological diseases.

Serum autotaxin is a prognostic indicator of liver-related events in patients with non-alcoholic fatty liver disease.

Circulating autotaxin (ATX) levels have been reported to correlate with liver inflammation activity and liver fibrosis severity in patients with non-alcoholic fatty liver disease (NAFLD). The objective of this study is to investigate whether serum ATX could predict liver-related events (LRE) in NAFLD patients. This retrospective investigation includes 309 biopsy-proven NAFLD patients registered at Shinshu University Hospital. All patients are followed for at least 1 year, during which time the prevalence of LRE, including newly developing hepatocellular carcinoma, hepatic encephalopathy, ascites, and esophagogastric varices, is investigated in relation to ATX levels at the time of liver biopsy. During the median follow-up period of 7.0 years, LRE are observed in 20 patients (6.5%). The area under the receiver operating characteristic curve and cut-off value of serum ATX for predicting LRE are 0.81 and 1.227 mg/l, respectively. Multivariate Cox proportional hazards models for LRE determine ATX and advanced fibrosis as independently associated factors. Furthermore, in a competing risk analysis that considered non-liver-related death as a competing event, ATX (HR 2.29, 95% CI 1.22-4.30, p = 0.010) is identified as an independent factor associated with LRE, along with advanced fibrosis (HR 8.01, 95% CI 2.10-30.60, p = 0.002). The predictive utility of ATX for LRE is validated in an independent cohort. Serum ATX may serve as a predictive marker for LRE in patients with NAFLD.

The Arg/Arg genotype of leptin receptor gene Gln223Arg polymorphism may be an independent risk factor for nonalcoholic fatty liver disease.

Given that obesity and insulin resistance play key roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and the connection between leptin and these metabolic diseases, the association between NAFLD and a leptin receptor gene (LEPR) polymorphism was examined. In this genetic case-control association study, 144 biopsy-proven NAFLD patients and 144 controls were genotyped for the LEPR gene Gln223Arg (rs1137101) polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. The distributions of genotypes and alleles of Gln223Arg variant were in accordance with the Hardy-Weinberg equilibrium in the study groups (P>.05). Multivariate logistic regression analysis showed that the LEPR Gln223Arg Arg/Arg genotype was an independent risk factor for NAFLD; the Arg/Arg genotype, compared with the Gln/Gln genotype, was associated with a 2.09-fold increased risk for NAFLD (P=.036, odds ratio=2.09 [95% CI = 1.31-5.95]). We found that the LEPR Gln223Arg Arg/Arg genotype was independently associated with a more than 2-fold rise in biopsy-proven NAFLD risk. Our findings, however, need to be corroborated by further studies.

Non-Hispanic Black persons with nonalcoholic fatty liver disease have lower rates of advanced fibrosis, cirrhosis, and liver-related events even after controlling for clinical risk factors and PNPLA3 genotype.

Nonalcoholic fatty liver disease (NAFLD) is less frequent in non-Hispanic persons (NHB) but there are knowledge gaps in our understanding of disease severity and outcomes of NAFLD in NHB. We compared liver histology and clinical outcomes of NAFLD in NHB and non-Hispanic White adults (NHW). We compared liver histology and outcomes of 109 NHB and 1910 NHW adults with biopsy proven NAFLD participating in the Nonalcoholic Steatohepatitis Clinical Research Network observational studies. The relationship between self-reported NHB race/ethnicity and advanced fibrosis was assessed via multivariable logistic regression after controlling for clinical co-variates and PNPLA3 genotype. NHB and NHW with NAFLD had similar NAFLD activity scores (NAS, 4.4 vs 4.3, p=0.87) and proportions with definite NASH (59% vs 58%, p=1.0), but NHB had significantly lower rates of advanced fibrosis (22% vs 34%, p=0.01) or cirrhosis (4.6% vs 12.1%, p=0.010). Compared to NHW, NHB had significantly lower frequency of advanced fibrosis (OR: 0.48, 95% CI:.27-0.86, p=0.01). In a comparison between 24 NHB and 655 NHW with advanced fibrosis, the NAS (5.6 vs 4.9, p=0.01) and lobular inflammation grade (2.2 vs 1.7, p<0.002) were significantly higher among NHB with advanced fibrosis. One NHB and 23 NHW died during follow-up (0.30 vs 0.28 per 100 person-year follow-up). Seven and zero liver-related deaths occurred in NHW and NHB with NAFLD respectively. The risk of advanced fibrosis in NHB with NAFLD is significantly lower, after controlling for clinical risk factors and PNPLA3 genotype. Although their risk for advanced fibrosis was low, NHB with NAFLD and advanced fibrosis had higher NAS and lobular inflammation, indicating a difference in their relationship between necroinflammation and fibrosis.

17-Beta-Hydroxysteroid Dehydrogenase 13 Loss of Function Does Not Confer Protection to Nonalcoholic Fatty Liver Disease in Indian Population

A splice variant in HSD17B13 gene is demonstrated to protect against nonalcoholic fatty liver disease (NAFLD), and mitigate the effect of Patatin-like phospholipase domain-containing 3 (PNPLA3-I148M). It is being explored as a putative drug target and in polygenic risk scores. Based on whole exome sequencing (WES) in our cohort of biopsy proven NAFLD and limited data on the variant in our ethnicity, we sought to explore its role. This is a cross-sectional study that recruited 1,020 individuals with ultrasound/biopsy-confirmed NAFLD and matched controls. Liver enzymes and lipid profiles were estimated (Beckman coulter LX750/DXH800); WES was performed in NAFLD patients and controls (Illumina; HiSeqX); HSD17B13-A-INS/I148M-PNPLA3 variants were genotyped (sequencing/qR T-PCR); HSD17B13 protein expression was estimated (immunohistochemistry); the Student's t-test/Mann-Whitney U/Chi-square test and odds ratio (95% confidence interval) were used. There was no significant difference (Odds ratio=0.76; 95% CI -0.57 to 1.03; P=0.76) in the frequency of the rs72613567-A-INS between controls and patients (17.8% vs. 14.4%). No difference in the ALT (Alanine transaminase; 72.24±65.13 vs. 73.70±60.06; P=0.51) and AST levels (Aspartate aminotransferase; 60.72±55.59 vs. 61.63±60.33; P=0.91) between HSD17B13-wild and variant carriers were noted. Significantly elevated liver enzymes were seen in PNPLA3-148-variant/HSD17B13-wild compared with PNPLA3-148-variant/HSD17B13-variant (90.44±59.0 vs. 112.32±61.78; P=0.02). No difference in steatosis (P=0.51) between HSD17B13-wild and variant carriers was noted. No other variants in the intron-exon boundaries were identified. Although, protein expression differences were noted between wild and variant carriers, no difference in the extent of steatosis was seen. Our study reports lack of association of the splice variant with reduced risk of NAFLD, and mitigating the effect of PNPLA3 variant. Ethnicity-based validation must be carried out before including it in assessing protection against NAFLD.

Lipid accumulation product is a valid predictor of hepatic steatosis and nonalcoholic fatty liver disease.

Aims: To evaluate and compare lipid accumulation product (LAP) with alanine aminotransferase (ALT), aspartate aminotransferase (AST), visceral adiposity index (VAI) and triglyceride-glucose index (TyG) as biomarkers for hepatic steatosis and nonalcoholic fatty liver disease (NAFLD). Methods: LAP, ALT, AST, VAI and TyG were measured in 52 biopsy-proven NAFLD patients and 21 control subjects. Additionally, LAP was also measured in 448 ultrasound-proven NAFLD patients and 1009 control subjects. Results: LAP was positively associated with hepatic steatosis and inflammation in biopsy-proven NAFLD. The risk of NAFLD was positively related to LAP and TyG, but LAP showed a better area under the receiver operating characteristic curve for hepatic steatosis and NAFLD. LAP also performed well in recognizingultrasound-proven NAFLD. Conclusion: LAP is an ideal biomarker of hepatic steatosis and NAFLD.

A Composite Blood Biomarker Including AKR1B10 and Cytokeratin 18 for Progressive Types of Nonalcoholic Fatty Liver Disease.

We aimed to evaluate whether composite blood biomarkers including aldo-keto reductase family 1 member B10 (AKR1B10) and cytokeratin 18 (CK-18; a nonalcoholic steatohepatitis [NASH] marker) have clinically applicable performance for the diagnosis of NASH, advanced liver fibrosis, and high-risk NASH (NASH+significant fibrosis). A total of 116 subjects including healthy control subjects and patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) were analyzed to assess composite blood-based and imaging-based biomarkers either singly or in combination. A composite blood biomarker comprised of AKR1B10, CK-18, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) showed excellent performance for the diagnosis of, NASH, advanced fibrosis, and high-risk NASH, with area under the receiver operating characteristic curve values of 0.934 (95% confidence interval [CI], 0.888 to 0.981), 0.902 (95% CI, 0.832 to 0.971), and 0.918 (95% CI, 0.862 to 0.974), respectively. However, the performance of this blood composite biomarker was inferior to that various magnetic resonance (MR)-based composite biomarkers, such as proton density fat fraction/MR elastography- liver stiffness measurement (MRE-LSM)/ALT/AST for NASH, MRE-LSM+fibrosis-4 index for advanced fibrosis, and the known MR imaging-AST (MAST) score for high-risk NASH. Our blood composite biomarker can be useful to distinguish progressive forms of NAFLD as an initial noninvasive test when MR-based tools are not available.

Transient Elastography Is the Best-Performing Non-Invasive Test of Liver Fibrosis in Obese Asian Patients with Non-Alcoholic Fatty Liver Disease: A Pilot, Cross-Sectional Study.

Background and Objectives: The prevalence of NAFLD (non-alcoholic fatty liver disease) is increasing, and up to 64% of Asian patients with NAFLD are obese. Non-invasive tests (NITs) for the assessment of liver fibrosis are increasingly being used, but data on their performance in obese Asian patients are lacking. In this pilot cross-sectional study, we aim to compare the distribution of serum and radiological markers of fibrosis between obese Asian biopsy-proven NAFLD patients with and without fibrosis and estimate the diagnostic accuracies of these indices. Materials and Methods: Obese Asian patients with NAFLD and who had undergone a liver biopsy showing histological evidence of NAFLD were invited to participate. Liver fibrosis was assessed using laboratory (APRI, AAR, BARD, FIB4, NFS, and Asia-Pacific NAFLD advanced fibrosis score) and imaging modalities (TE: transient elastography, MRE: magnetic resonance elastography, and SWU: shear wave ultrasonography). Results: A total of 16 patients were included in the final analysis. On liver biopsy, nine patients (56.3%) had significant fibrosis (F2 or higher), and six of these patients had advanced fibrosis (F3 or higher). F4 fibrosis was present in one patient (6.3%). For the laboratory markers, we found that the BARD score correctly identified five out of six patients with advanced fibrosis (83.4%, p value 0.045). Among all the NITs studied, liver stiffness measured by TE had the highest accuracy of 87.5% in its established threshold of 8.5 kPa for the detection of advanced fibrosis. MRE also performed well (81.2% in 3.64 kPa). Conclusions: In conclusion, TE has performed well in the detection of advanced fibrosis in obese Asian patients with biopsy-proven NAFLD in our pilot study. Further large-scale definitive studies are needed to validate the results of our findings.

Association of chronic hepatitis B infection with hepatic steatosis and injury in nonalcoholic fatty liver disease children

BackgroundThe influence of chronic hepatitis B infection (CBI) on hepatic steatosis, necroinflammation, and fibrosis in nonalcoholic fatty liver disease (NAFLD) population was unclear. We aimed to investigate the effect of CBI on hepatic steatosis and assess the association between NAFLD co-existed CBI and hepatic injury in NAFLD pediatric population.MethodsConsecutive hospitalized children with biopsy-proven NAFLD with or without CBI were included. Hepatic steatosis, necroinflammation and fibrosis were evaluated by NASH CRN system and/or METAVIR scoring system, appropriately. Using multivariate logistic analysis, we identified variables associated with hepatic steatosis and liver injury.ResultsOf 223 biopsy-proven NAFLD children, 161 were NAFLD without CBI, and 62 were NAFLD co-existed CBI. Grouped by mild, moderate and severe hepatic steatosis, there was an inverse association between CBI and the severity of hepatic steatosis [odd ratio (OR) 0.037, 95% confidence interval (CI) 0.014–0.098]. In addition, we explored the relationship between CBI and hepatic necroinflammation and fibrosis in NAFLD children. Hepatic necroinflammation and fibrosis, respectively, were divided into two groups according to severity. And CBI was positively associated with hepatic necroinflammation (OR 6.125, 95%CI 1.958–19.158). However, there was no statistically independent association between CBI and significant hepatic fibrosis.ConclusionsCBI was inverse associated with the grade of steatosis and positively associated with severe hepatic necroinflammation, and does not appear to affect significant hepatic fibrosis in pediatric NAFLD children.

Accuracy of the Enhanced Liver Fibrosis Test in Patients With Type 2 Diabetes Mellitus and Its Clinical Implications

Background and AimsThe diagnostic performance of the Fibrosis-4 (FIB-4) index and nonalcoholic fatty liver disease (NAFLD) fibrosis score (NFS) is poor in patients with type 2 diabetes mellitus (T2DM). We determined the usefulness of the enhanced liver fibrosis (ELF) test in patients with T2DM. MethodsA total of 1,228 patients with biopsy-proven NAFLD were enrolled. The diagnostic performance of the ELF test for predicting advanced fibrosis in participants with or without T2DM was evaluated in comparison with the FIB-4 index and NFS. ResultsOverall, the area under the curve of the ELF test for predicting advanced fibrosis was greater (0.828) than that of the FIB-4 index (0.727) and NFS (0.733). The diagnostic performance of the ELF test (area under the curve 0.820) was also superior to that of the FIB-4 index (0.698) and NFS (0.700) in patients with T2DM. With the low cutoff values for each non-invasive test, the ELF test provided an acceptable false-negative rate (cutoff value 9.8, 6.7%) in this population, unlike the FIB-4 index (1.30, 14.5%) and NFS (−1.455, 12.4%). After propensity score matching to avoid selection bias including age, sex, body mass index, and the prevalence of advanced fibrosis, the ELF test with a low cutoff value showed a high sensitivity (≥91.4%) and a high negative predictive value (≥96.8%), irrespective of the presence or absence of T2DM. ConclusionThe high diagnostic performance of the ELF test for predicting advanced fibrosis in individuals with or without T2DM could address an unmet medical need for accurate assessment of liver fibrosis in patients with diabetes and NAFLD.

Diagnostic accuracy of AGILE 3+ score for advanced fibrosis in patients with NAFLD: A systematic review and meta-analysis.

A simple noninvasive score, the Agile 3+ score, combining liver stiffness measurement, aspartate aminotransferase/alanine aminotransferase ratio, platelet count, diabetes status, sex, and age, has been proposed for the identification of advanced fibrosis in patients with suspected NAFLD. We performed a systematic review and meta-analysis of observational studies to evaluate the diagnostic accuracy of the Agile 3+ score in identifying patients with NAFLD and advanced fibrosis. Recently, an International consensus changed the nomenclature of NAFLD into metabolic-associated steatotic liver disease, so currently, the two terms are interchangeable. We systematically searched MEDLINE, Ovid Embase, Scopus, and Cochrane Library electronic databases for full-text published articles in any language from the inception to the April 24, 2023. We included original articles reporting data on the sensitivity and specificity of the Agile 3+ score, according to previously described rule-out (≤ 0.451) and rule-in (≥ 0.679) cutoffs. We included 6 observational studies (total of 6955 participants) with biopsy-proven NAFLD [mean age 53 (SE 4) years, mean body mass index 30.9 (SE 2.3) kg/m 2 , 54.0% men, prevalence of diabetes 59.6%]. The pooled prevalence of advanced fibrosis (≥ F3) was 42.1%. By the rule-out cutoff, the overall sensitivity and specificity were 88% (95% CI: 81-93%; I2 = 89.2%) and 65% (95% CI: 54-75%; I2 = 97.6%), respectively. By the rule-in cutoff, the overall sensitivity and specificity were 68% (95% CI: 57-78%; I2 =91.1%) and 87% (95% CI: 80%-92%; I2 =96.7%), respectively. Meta-regression analyses reported that the diagnostic accuracy was partly mediated by age ( p < 0.01), body mass index ( p < 0.01), and, although not statistically significant, sex ( p = 0.06). Our systematic review and meta-analysis suggests that Agile 3+ accurately diagnoses NAFLD with advanced fibrosis and can identify patients eligible for biopsy and emerging pharmacotherapies.

Insulin-like growth factor binding protein 3 promoter variant (rs2854744) is associated with nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and a growing global epidemic. In NAFLD, liver fat surpasses 5% of hepatocytes without the secondary causes of lipid accumulation or excessive alcohol consumption. Given the link between NAFLD and insulin resistance, the possible association between the rs2854744 (-202 G>T) promoter polymorphism of insulin-like growth factor binding protein 3 (IGFBP3) gene and NAFLD was investigated in this study. In this genetic case-control association study, the IGFBP3 rs2854744 genotypes of 315 unrelated individuals, including 156 patients with biopsy-proven NAFLD and 159 controls, were determined using polymerase chain reaction/restriction fragment length polymorphism analyses. The "GT+TT" genotype of the IGFBP3 rs2854744 polymorphism, compared with the "GG" genotype, was associated with a 2.7-fold increased risk of NAFLD after adjustment for confounding factors (P = 0.009; odds ratio [OR] = 2.71; 95% confidence interval [CI] = 1.19-3.18). Additionally, the IGFBP3 rs2854744 "T" allele, in comparison with the "G" allele, was significantly overrepresented in NAFLD patients than the controls (P = 0.008; OR = 1.85; 95%CI = 1.23-2.94). Our findings first indicated that the IGFBP3 rs2854744 "GT+TT" genotype is a marker of increased NAFLD susceptibility; however, it needs to be supported by further investigations in other populations.

Abstract 16282: Incident Heart Failure With Preserved Ejection Fraction in a Cohort of Patients With Biopsy-Proven Non-Alcoholic Fatty Liver Disease

Introduction: Non-alcoholic fatty liver disease (NAFLD) is associated with heart failure with preserved ejection fraction (HFpEF), independent of shared risk factors. The aim of this study was to determine the prevalence, clinical, and echocardiographic (TTE) features of HFpEF in patients with biopsy-proven NAFLD. Methods: We performed a retrospective single-center cohort study of patients with biopsy-proven NAFLD in the Duke NAFLD Biorepository and Clinical Database. Study entry was at the time of liver biopsy and patients were followed until death or 5/1/2023. Clinical and echocardiographic data were abstracted via manual chart review. HFpEF was defined as: at least one TTE characteristic (left atrial volume index ≥ 29 ml/m 2 , septal wall thickness ≥ 1 cm, or evidence of diastolic dysfunction) and signs or symptoms of heart failure (diagnosis of heart failure on problem list, hospitalization for heart failure, elevated NT pro-BNP level, jugular venous distention, use of loop diuretics, pulmonary or peripheral edema, fatigue, or exertional symptoms). Descriptive statistics were evaluated. Results: A total of 742 patients were included in the study. The mean age of the cohort was 50 +/- 12 years, and 83% were White. 95 (13%) had TTE both prior to study entry and during follow up, while 279 patients (38%) had TTE only during follow up. A total of 185 patients met criteria for HFpEF during follow up. After removing patients with TTE evidence of HFpEF prior to study entry, there were 132 cases of incident HFpEF over a mean follow up of 9.1 years, representing 47% of those with TTE after liver biopsy, and 18% of the overall cohort. Considering only TTE criteria, 142 patients had incident HFpEF. During follow up, 12 patients were hospitalized for heart failure. Conclusions: HFpEF is common in patients with NAFLD and a small percentage of patients do not have a chart diagnosis despite meeting echocardiographic criteria, suggesting that HFpEF may be under-recognized. Screening for HFpEF and/or formal care pathways to address early heart failure will be important to prevent morbidity and mortality in this population.

Abstract 12321: Discordant Association of Nonalcoholic Fatty Liver Disease With Lipoprotein(a) and Markers of Atherogenic Dyslipidemia

Background: Nonalcoholic fatty liver disease (NAFLD) is associated with atherogenic dyslipidemia and an increased risk of cardiovascular events. Previous studies have suggested a paradoxical inverse relationship between NAFLD severity and Lp(a) level, an independent cardiovascular risk factor. However, contemporary data in patients with biopsy-proven NAFLD in the U.S. are lacking. Hypothesis: NAFLD severity on liver biopsy has a discordant association with Lp(a) and other markers of atherogenic dyslipidemia. Methods: Lp(a), traditional lipid profile, apolipoproteins, and nuclear magnetic resonance-based lipoprotein particle concentration were measured in 151 patients with NAFLD. Levels were compared between those with nonalcoholic fatty liver (NAFL) on histology and non-alcoholic steatohepatitis (NASH), the clinically aggressive NAFLD variant. Results: Median age was 55 [48, 62] years, 67% of patients were women, 83% were White, 43% had NAFL, and 57% had NASH. Demographic characteristics were similar among those with NAFL and NASH. Triglyceride level was higher and High-Density Lipoprotein-cholesterol (HDL-C) was lower among those with NASH as compared with NAFL. Circulating concentration of two key markers of atherogenic dyslipidemia, Apolipoprotein-B (apoB) and Low-Density Lipoprotein particle concentration (LDL-P) was 9% and 17% higher in the NASH group as compared with NAFL, respectively. Contrastingly, Lp(a) concentration was 50% lower in NASH relative to NAFL group (Figure). Hepatocyte ballooning, lobular inflammation, and fibrosis on histology were inversely associated with Lp(a) concentration, while steatosis severity was not. Conclusions: NAFLD severity has a discordant association with Lp(a) and markers of atherogenic dyslipidemia. The mechanistic basis of this relationship may have implications for prognosticating cardiovascular disease risk and determining the safety of targeted Lp(a) lowering in patients with NAFLD.

Discordant association of nonalcoholic fatty liver disease with lipoprotein(a) and markers of atherogenic dyslipidemia

Nonalcoholic fatty liver disease (NAFLD) is associated with atherogenic dyslipidemia and an increased risk of cardiovascular events. Previous studies have suggested an inverse relationship between NAFLD severity and lipoprotein(a) [Lp(a)] level, but contemporary data from the U.S. are lacking. Lp(a), lipid profile, apolipoproteins, and nuclear magnetic resonance-based lipoprotein particle concentrations were measured in 151 patients with biopsy-proven NAFLD. Levels were compared between those with nonalcoholic fatty liver (NAFL) on histology and non-alcoholic steatohepatitis (NASH). Median age was 55 [48, 62] years, 67% of patients were women, 83% were White, 43% had NAFL, and 57% had NASH. Triglyceride level was higher and high-density lipoprotein-cholesterol (HDL-C) was lower among those with NASH as compared with NAFL. Circulating apolipoprotein-B (ApoB) and low-density lipoprotein particle concentration (LDL-P) were 9% and 17% higher in the NASH group as compared with NAFL, respectively. Contrastingly, Lp(a) concentration was 50% lower in NASH relative to NAFL group. Hepatocyte ballooning, lobular inflammation, and fibrosis on histology were inversely associated with Lp(a) concentration. NAFLD severity has a discordant association with Lp(a) and other markers of atherogenic dyslipidemia. This relationship may have implications for prognosticating cardiovascular disease risk in patients with NAFLD.

SIRT5 rs12216101 T>G variant is associated with liver damage and mitochondrial dysfunction in patients with non-alcoholic fatty liver disease

Sirtuin 5, encoded by the SIRT5 gene, is a NAD+-dependent deacylase that modulates mitochondrial metabolic processes through post-translational modifications. In this study, we aimed to examine the impact of the SIRT5 rs12216101T>G non-coding single nucleotide polymorphism on disease severity in patients with non-alcoholic fatty liver disease (NAFLD). The rs12216101 variant was genotyped in 2,606 consecutive European patients with biopsy-proven NAFLD. Transcriptomic analysis, expression of mitochondrial complexes and oxidative stress levels were measured in liver samples from a subset of bariatric patients. Effects of SIRT5 pharmacological inhibition were evaluated in HepG2 cells exposed to excess free fatty acids. Mitochondrial energetics invitro were investigated by high-performance liquid chromatography. In the whole cohort, the frequency distribution of SIRT5 rs12216101 TT, TG and GG genotypes was 47.0%, 42.3% and 10.7%, respectively. At multivariate logistic regression analysis adjusted for sex, age >50 years, diabetes, and PNPLA3 rs738409 status, the SIRT5 rs12216101T>G variant was associated with the presence of non-alcoholic steatohepatitis (odds ratio 1.20, 95% CI 1.03-1.40) and F2-F4 fibrosis (odds ratio 1.18; 95% CI 1.00-1.37). Transcriptomic analysis showed that the SIRT5 rs12216101T>G variant was associated with upregulation of transcripts involved in mitochondrial metabolic pathways, including the oxidative phosphorylation system. In patients carrying the G allele, western blot analysis confirmed an upregulation of oxidative phosphorylation complexes III, IV, V and consistently higher levels of reactive oxygen species, reactive nitrogen species and malondialdehyde, and lower ATP levels. Administration of a pharmacological SIRT5 inhibitor preserved mitochondrial energetic homeostasis in HepG2 cells, as evidenced by restored ATP/ADP, NAD+/NADH, NADP+/NADPH ratios and glutathione levels. The SIRT5 rs12216101T>G variant, heightening SIRT5 activity, is associated with liver damage, mitochondrial dysfunction, and oxidative stress in patients with NAFLD. In this study we discovered that the SIRT5 rs12216101T>G variant is associated with higher disease severity in patients with non-alcoholic fatty liver disease (NAFLD). This risk variant leads to a SIRT5 gain-of-function, enhancing mitochondrial oxidative phosphorylation and thus leading to oxidative stress. SIRT5 may represent a novel disease modulator in NAFLD.

Development of Fibro-PeN, a clinical prediction model for moderate-to-severe fibrosis in children with nonalcoholic fatty liver disease.

Liver fibrosis is common in children with NAFLD and is an important determinant of outcomes. High-performing noninvasive models to assess fibrosis in children are needed. The objectives of this study were to evaluate the performance of existing pediatric and adult fibrosis prediction models and to develop a clinical prediction rule for identifying moderate-to-severe fibrosis in children with NAFLD. We enrolled children with biopsy-proven NAFLD in the Nonalcoholic Steatohepatitis Clinical Research Network within 90 days of liver biopsy. We staged liver fibrosis in consensus using the Nonalcoholic Steatohepatitis Clinical Research Network scoring system. We evaluated existing pediatric and adult models for fibrosis and developed a new pediatric model using the least absolute shrinkage and selection operator with linear and spline terms for discriminating moderate-to-severe fibrosis from none or mild fibrosis. The model was internally validated with 10-fold cross-validation. We evaluated 1055 children with NAFLD, of whom 26% had moderate-to-severe fibrosis. Existing models performed poorly in classifying fibrosis in children, with area under the receiver operator curves (AUC) ranging from 0.57 to 0.64. In contrast, our new model, fibrosis in pediatric NAFLD was derived from fourteen common clinical variables and had an AUC of 0.79 (95% CI: 0.77-0.81) with 72% sensitivity and 76% specificity for identifying moderate-to-severe fibrosis. Existing fibrosis prediction models have limited clinical utility in children with NAFLD. Fibrosis in pediatric NAFLD offers improved performance characteristics for risk stratification by identifying moderate-to-severe fibrosis in children with NAFLD.

In the Diagnosis of Liver Fibrosis Developing in Nonalcoholic Fatty Liver Patients; Could Serum Fetuin A Be a Candidate Biomarker

Previous studies have reported in the literature that fetuin A, released from the liver, may be a useful serum biomarker in the diagnosis of nonalcoholic fatty liver disease (NAFLD). However, results are not consistent in predicting nonalcoholic steatohepatitis (NASH) and fibrosis, which are indicative of progressive NAFLD patients. The aim of this study was to investigate the importance of serum fetuin A in detecting NASH and fibrosis, which are determinants of morbidity, in patients with liver biopsy-proven NAFLD. This observational case-control study included 40 NAFLD patients diagnosed by liver biopsy and 25 healthy volunteer controls. The demographic characteristics of the patients and healthy volunteers were recorded, biochemical tests were done, and the serum fetuin A levels of the participants were determined by the enzyme-linked immunosorbent assay method. Serum fetuin A levels were significantly higher in both the nonalcoholic fatty liver (NAFL) (608.30 μg/mL; p&lt;0.001) and NAFLD (536.58 μg/mL; p=0.008) groups compared to the control group (345.07 μg/mL). However, no significant difference was detected in the NASH group (417.06 μg/mL; p=0.740). When patients with and without fibrosis were compared, the mean serum fetuin A levels of patients with fibrosis were significantly lower (708 μg/mL and 380 μg/mL, respectively; p&lt;0.001). When receiver operating characteristic (ROC) analysis was performed, the best cut-off point for patients with fibrosis was 510.98 μg/mL with 94.7% sensitivity and 66.7% specificity (p&lt;0.001). Serum fetuin A may be a useful biomarker in the diagnosis of NAFLD patients and in predicting liver fibrosis.

A nutrigenetic precision approach for the management of non-alcoholic fatty liver disease

The Patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 single nucleotide polymorphism (SNP) is one of the major genetic determinant of non-alcoholic fatty liver disease (NAFLD) and is strongly regulated by changes in energy balance and dietary factors. We aimed to investigate the association between the PNPLA3 rs738409 SNP, nutrient intake and NAFLD severity. PNPLA3-rs738409 SNP was genotyped in 181 patients with NAFLD who completed the EPIC Food Frequency Questionnaire. Liver steatosis was evaluated by Controlled Attenuation Parameter (CAP) (Fibroscan®530, Echosens). According to the established cut-off, a CAP value≥300dB/m was used to identify severe steatosis (S3). An independent group of 46 biopsy-proven NAFLD subjects was used as validation cohort. Overall, median age was 53 years (range 44; 62) and 60.2% of patients were male. Most subjects (56.3%) had S3 and showed increased liver stiffness (p<0.001), AST (p=0.003) and ALT levels (p<0.001) compared to those with CAP<300dB/m. At logistic regression analyses we found that the interaction between carbohydrates intake and the carriers of the PNPLA3 G risk allele was significantly associated with S3 (p=0.001). The same result was confirmed in the validation cohort, were the interaction between high carbohydrate intake (48%) and PNPLA3 SNP was significantly associated with steatosis ≥33% (p=0.038). The intake of greater than or equal to 48% carbohydrate in NAFLD patients carriers of the CG/GG allele of PNPLA3 rs738409 may increase the risk of significant steatosis.

Exercise Does Not Independently Improve Histological Outcomes in Biopsy-Proven Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis.

The independent effect of exercise on liver histology in non-alcoholic fatty liver disease (NAFLD) remains unclear. As such, we conducted a systematic review and meta-analysis of the effect of exercise alone on histological endpoints in biopsy-proven NAFLD. A systematic literature search was conducted to include controlled clinical trials investigating the effect of exercise alone on liver histology in biopsy-proven NAFLD. Meta-analysis was conducted for histological outcomes with available data from a minimum of three studies. Pooled estimates of the effect of exercise on histological endpoints were calculated using random-effects models. We identified three controlled clinical trials that assessed the independent effect of exercise on histological outcomes in patients with biopsy-proven NAFLD. The studies consisted of 72 total participants, including 40 subjects in the exercise intervention and 32 individuals in the comparison group. Meta-analysis showed that exercise did not significantly improve Brunt grade, NAFLD activity score, and fibrosis in NAFLD. Exercise alone may not lead to significant histopathological improvement in NAFLD. Future well-powered randomized controlled trials are needed to better characterize the impact of exercise on histological outcomes and clinical endpoints.