The PD-1/PD-L1 Axis in the Biology of MASLD.

Metabolic Dysfunction-Associated Steatotic Liver (MASL), previously named nonalcoholic fatty liver (NAFL), is a multifactorial disease in which metabolic, genetic, and environmental risk factors play a predominant role. Obesity and type 2 diabetes act as triggers of the inflammatory response, which contributes to the progression of MASL to Metabolic Dysfunction-Associated Steatohepatitis and the development of hepatocellular carcinoma. In the liver, several parenchymal, nonparenchymal, and immune cells maintain immunological homeostasis, and different regulatory pathways balance the activation of the innate and adaptative immune system. PD-1/PD-L1 signaling acts, in the maintenance of the balance between the immune responses and the tissue immune homeostasis, promoting self-tolerance through the modulation of activated T cells. Recently, PD-1 has received much attention for its roles in inducing an exhausted T cells phenotype, promoting the tumor escape from immune responses. Indeed, in MASLD, the excessive fat accumulation dysregulates the immune system, increasing cytotoxic lymphocytes and decreasing their cytolytic activity. In this context, T cells exacerbate liver damage and promote tumor progression. The aim of this review is to illustrate the main pathogenetic mechanisms by which the immune system promotes the progression of MASLD and the transition to HCC, as well as to discuss the possible therapeutic applications of PD-1/PD-L1 target therapy to activate T cells and reinvigorate immune surveillance against cancer.

Are we ready for genetic testing in metabolic dysfunction-associated steatotic liver disease?

Metabolic dysfunction-associated steatotic liver disease (MASLD), with its steadily increasing prevalence, represents now a major problem in public health. A proper referral could benefit from tools allowing more precise risk stratification. To this end, in recent decades, several genetic variants that may help predict and refine the risk of development and progression of MASLD have been investigated. In this review, we aim to discuss the role genetics in MASLD plays in everyday clinical practice. We performed a comprehensive literature search of PubMed for relevant publications. Available evidence highlights the emergence of genetic-based noninvasive algorithms for diagnosing fatty liver, metabolic dysfunction-associated steatohepatitis, fibrosis progression and occurrence of liver-related outcomes including hepatocellular carcinoma. Nevertheless, their accuracy is not optimal and application in everyday clinical practice remains challenging. Furthermore, susceptible genetic markers have recently become subjects of great scientific interest as therapeutic targets in precision medicine. In conclusion, decisional algorithms based on genetic testing in MASLD to facilitate the clinician decisions on management and treatment are under growing investigation and could benefit from artificial intelligence methodology.

Vibration-Controlled Transient Elastography Scores to Predict Liver-Related Events in Steatotic Liver Disease.

Importance: Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently the most common chronic liver disease worldwide. It is important to develop noninvasive tests to assess the disease severity and prognosis. Objective: To study the prognostic implications of baseline levels and dynamic changes of the vibration-controlled transient elastography (VCTE)-based scores developed for the diagnosis of advanced fibrosis (Agile 3+) and cirrhosis (Agile 4) in patients with MASLD. Design, Setting, and Participants: This cohort study included data from a natural history cohort of patients with MASLD who underwent VCTE examination at 16 tertiary referral centers in the US, Europe, and Asia from February 2004 to January 2023, of which the data were collected prospectively at 14 centers. Eligible patients were adults aged at least 18 years with hepatic steatosis diagnosed by histologic methods (steatosis in ≥5% of hepatocytes) or imaging studies (ultrasonography, computed tomography or magnetic resonance imaging, or controlled attenuation parameter ≥248 dB/m by VCTE). Main Outcomes and Measures: The primary outcome was liver-related events (LREs), defined as hepatocellular carcinoma or hepatic decompensation (ascites, variceal hemorrhage, hepatic encephalopathy, or hepatorenal syndrome), liver transplant, and liver-related deaths. The Agile scores were compared with histologic and 8 other noninvasive tests. Results: A total of 16 603 patients underwent VCTE examination at baseline (mean [SD] age, 52.5 [13.7] years; 9600 [57.8%] were male). At a median follow-up of 51.7 (IQR, 25.2-85.2) months, 316 patients (1.9%) developed LREs. Both Agile 3+ and Agile 4 scores classified fewer patients between the low and high cutoffs than most fibrosis scores and achieved the highest discriminatory power in predicting LREs (integrated area under the time-dependent receiver-operating characteristic curve, 0.89). A total of 10 920 patients (65.8%) had repeated VCTE examination at a median interval of 15 (IQR, 11.3-27.7) months and were included in the serial analysis. A total of 81.9% of patients (7208 of 8810) had stable Agile 3+ scores and 92.6% of patients (8163 of 8810) had stable Agile 4 scores (same risk categories at both assessments). The incidence of LREs was 0.6 per 1000 person-years in patients with persistently low Agile 3+ scores and 30.1 per 1000 person-years in patients with persistently high Agile 3+ scores. In patients with high Agile 3+ score at baseline, a decrease in the score by more than 20% was associated with substantial reduction in the risk of LREs. A similar trend was observed for the Agile 4 score, although it missed more LREs in the low-risk group. Conclusions and Relevance: Findings of this study suggest that single or serial Agile scores are highly accurate in predicting LREs in patients with MASLD, making them suitable alternatives to liver biopsy in routine clinical practice and in phase 2b and 3 clinical trials for steatohepatitis.

ANGPTL3 Downregulation Increases Intracellular Lipids by Reducing Energy Utilization.

BACKGROUND: ANGPTL3 (angiopoietin-like protein 3) is a circulating protein with a key role in maintaining lipoprotein homeostasis. A monoclonal antibody against ANGPTL3 is an approved and well-tolerated treatment to reduce lipoproteins in familial hypercholesterolemia homozygotes. However, the reduction of hepatic ANGPTL3 synthesis using an antisense oligonucleotide unexpectedly resulted in a dose-dependent increase in liver lipid content and circulating transaminases, resulting in the termination of the clinical trial. Meanwhile, the use of silencing RNAs remains an area of active investigation. Our study sought to investigate whether intracellular downregulation of ANGPTL3 may lead to a primary increase in neutral lipids within the hepatocyte. METHODS: We downregulated ANGPTL3 by silencing RNA in primary human hepatocytes 3-dimensional spheroids, HepG2/LX-2 3-dimensional spheroids, and in HepG2, Hep3B2, and Huh7 cultured in 2 dimensions. RESULTS: ANGPTL3 downregulation increased neutral lipids in all models investigated. Interestingly, ANGPTL3 induced lower intracellular deiodinase type 1 protein levels resulting in a reduction in beta-oxidation and causing an increase in triglycerides stored in lipid droplets. CONCLUSIONS: In conclusion, intracellular ANGPTL3 downregulation by silencing RNA led to an increase in triglycerides content due to a reduction in energy substrate utilization resembling a primary intracellular hepatocyte hypothyroidism.

Mitochondrial amidoxime-reducing component 1 p.Ala165Thr increases protein degradation mediated by the proteasome.

OBJECTIVE: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global health concern with no effective and specific drug treatment available. The rs2642438 minor allele in mitochondrial amidoxime-reducing component 1 (MARC1) results in an aminoacidic substitution (p.Ala165Thr) and associates with protection against MASLD. However, the mechanisms behind this protective effect are unknown. In this study, we examined the consequences of this aminoacidic substitution on protein stability and subcellular localization. METHODS: We overexpressed the human MARC1 A165 (wild-type) or 165T (mutant) in vivo in mice and in vitro in human hepatoma cells (HepG2 and HuH-7), generated several mutants at position 165 by in situ mutagenesis and then examined protein levels. We also generated HepG2 cells stably overexpressing MARC1 A165 or 165T to test the effect of this substitution on MARC1 subcellular localization. RESULTS: MARC1 165T overexpression resulted in lower protein levels than A165 both in vivo and in vitro. Similarly, any mutant at position 165 showed lower protein levels compared to the wild-type protein. We showed that the 165T mutant protein is polyubiquitinated and its degradation is accelerated through lysine-48 ubiquitin-mediated proteasomal degradation. We also showed that the 165T substitution does not affect the MARC1 subcellular localization. CONCLUSIONS: This study shows that alanine at position 165 in MARC1 is crucial for protein stability, and the threonine substitution at this position leads to a hypomorphic protein variant due to lower protein levels. Our result supports the notion that lowering hepatic MARC1 protein level may be a successful therapeutic strategy for treating MASLD.

Serum ferritin levels can predict long-term outcomes in patients with metabolic dysfunction-associated steatotic liver disease.

OBJECTIVE: Hyperferritinaemia is associated with liver fibrosis severity in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), but the longitudinal implications have not been thoroughly investigated. We assessed the role of serum ferritin in predicting long-term outcomes or death. DESIGN: We evaluated the relationship between baseline serum ferritin and longitudinal events in a multicentre cohort of 1342 patients. Four survival models considering ferritin with confounders or non-invasive scoring systems were applied with repeated five-fold cross-validation schema. Prediction performance was evaluated in terms of Harrell's C-index and its improvement by including ferritin as a covariate. RESULTS: Median follow-up time was 96 months. Liver-related events occurred in 7.7%, hepatocellular carcinoma in 1.9%, cardiovascular events in 10.9%, extrahepatic cancers in 8.3% and all-cause mortality in 5.8%. Hyperferritinaemia was associated with a 50% increased risk of liver-related events and 27% of all-cause mortality. A stepwise increase in baseline ferritin thresholds was associated with a statistical increase in C-index, ranging between 0.02 (lasso-penalised Cox regression) and 0.03 (ridge-penalised Cox regression); the risk of developing liver-related events mainly increased from threshold 215.5 µg/L (median HR=1.71 and C-index=0.71) and the risk of overall mortality from threshold 272 µg/L (median HR=1.49 and C-index=0.70). The inclusion of serum ferritin thresholds (215.5 µg/L and 272 µg/L) in predictive models increased the performance of Fibrosis-4 and Non-Alcoholic Fatty Liver Disease Fibrosis Score in the longitudinal risk assessment of liver-related events (C-indices>0.71) and overall mortality (C-indices>0.65). CONCLUSIONS: This study supports the potential use of serum ferritin values for predicting the long-term prognosis of patients with MASLD.

Prevalence and Determinants of Liver Disease in Relatives of Italian Patients With Advanced MASLD.

BACKGROUND & AIMS: Metabolic dysfunction associated steatotic liver disease (MASLD) has a strong genetic component. The aim of this study was to examine noninvasively the prevalence of MASLD and of advanced fibrosis in relatives of patients with advanced MASLD and the risk factors for liver involvement, with a focus on the contribution of common genetic risk variants. METHODS: We prospectively enrolled 98 consecutive probands with advanced fibrosis and/or hepatocellular carcinoma caused by MASLD and 160 nontwin first-degree relatives noninvasively screened for MASLD and advanced fibrosis at 4 Italian centers. We evaluated common genetic determinants and polygenic risk scores of liver disease. RESULTS: Among relatives, prevalence of MASLD was 56.8% overall, whereas advanced fibrosis was observed in 14.4%. At multivariable analysis in relatives, MASLD was associated with body mass index (odds ratio [OR], 1.31 [1.18-1.46]) and tended to be associated with diabetes (OR, 5.21 [0.97-28.10]), alcohol intake (OR, 1.32 [0.98-1.78]), and with female sex (OR, 0.54 [0.23-1.15]), whereas advanced fibrosis was associated with diabetes (OR, 3.13 [1.16-8.45]) and nearly with body mass index (OR, 1.09 [1.00-1.19]). Despite that the PNPLA3 risk variant was enriched in probands (P = .003) and overtransmitted to relatives with MASLD (P = .045), evaluation of genetic risk variants and polygenic risk scores was not useful to guide noninvasive screening of advanced fibrosis in relatives. CONCLUSIONS: We confirmed that about 1 in 7 relatives of patients with advanced MASLD has advanced fibrosis, supporting clinical recommendations to perform family screening in this setting. Genetic risk variants contributed to liver disease within families but did not meaningfully improve fibrosis risk stratification.

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

BACKGROUND AND AIMS: 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. APPROACH AND RESULTS: 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). CONCLUSIONS: 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.

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

BACKGROUND & AIMS: 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 rs12216101 T>G non-coding single nucleotide polymorphism on disease severity in patients with non-alcoholic fatty liver disease (NAFLD). METHODS: 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 in vitro were investigated by high-performance liquid chromatography. RESULTS: 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 rs12216101 T>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 rs12216101 T>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. CONCLUSIONS: The SIRT5 rs12216101 T>G variant, heightening SIRT5 activity, is associated with liver damage, mitochondrial dysfunction, and oxidative stress in patients with NAFLD. IMPACT AND IMPLICATIONS: In this study we discovered that the SIRT5 rs12216101 T>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.

Risk of liver-related events in metabolic dysfunction-associated steatohepatitis (MASH) patients with fibrosis: A comparative analysis of various risk stratification criteria.

BACKGROUND AND AIMS: International regulatory agencies recommend testing drug therapy for patients with noncirrhotic high-risk metabolic dysfunction-associated steatohepatitis (MASH) because they are at risk of liver-related events (LRE). We aimed to compare the risk of LRE in patients with MASLD stratified for F2-F4 fibrosis and MASH. APPROACH AND RESULTS: Overall, 1938 consecutive patients with biopsy-proven MASLD were enrolled. High-risk MASH was defined as MASH with F2-F4 fibrosis. LSM was measured by transient elastography. LRE were recorded during follow-up. Cox multivariate models were used to assess the association between high-risk MASH or F2-F4 fibrosis without MASH, of LSM (≥8 or ≥10 Kpa), and of AGILE 3+ with LRE. The diagnostic performance for the prediction of LRE was assessed using the area under the receiver operating characteristic curves. The observed 5-year actuarial rate of LRE was 0.4%, 0.2%, 5.1%, and 6.6% in patients with F0-F1 fibrosis without MASH, F0-F1 fibrosis with MASH, F2-F4 fibrosis without MASH, and high-risk MASH, respectively. At multivariate Cox regression analysis using F0-F1 fibrosis without MASH as a reference, both F2-F4 fibrosis without MASH [adjusted HR (aHR) 9.96] and high-risk MASH (aHR 10.14) were associated with LRE. In the 1074 patients with available LSM, LSM ≥ 10 kPa (aHR 6.31) or AGILE 3+ > 0.67 (aHR 27.45) independently predicted the development of LRE and had similarly acceptable 5-year area under the receiver operating characteristic to high-risk MASH and F2-F4 fibrosis (0.772, 0.818, 0.739, and 0.780, respectively). CONCLUSIONS: The risk of LRE is similar in patients with high-risk MASH and with F2-F4 fibrosis without MASH. The use of LSM ≥ 10 kPa or AGILE 3+ > 0.67 could be an accurate option to identify patients with MASLD worthy to be included in clinical trials.

Oesophageal varices predict complications in compensated advanced non-alcoholic fatty liver disease.

Background & Aims: We aimed to evaluate the impact of oesophageal varices (OV) and their evolution on the risk of complications of compensated advanced chronic liver disease (cACLD) caused by non-alcoholic fatty liver disease (NAFLD). We also assessed the accuracy of non-invasive scores for predicting the development of complications and for identifying patients at low risk of high-risk OV. Methods: We performed a retrospective assessment of 629 patients with NAFLD-related cACLD who had baseline and follow-up oesophagogastroduodenoscopy and clinical follow-up to record decompensation, portal vein thrombosis (PVT), and hepatocellular carcinoma. Results: Small and large OV were observed at baseline in 30 and 15.9% of patients, respectively. The 4-year incidence of OV from absence at baseline, and that of progression from small to large OV were 16.3 and 22.4%, respectively. Diabetes and a ≥5% increase in BMI were associated with OV progression. Multivariate Cox regression revealed that small (hazard ratio [HR] 2.24, 95% CI 1.47-3.41) and large (HR 3.86, 95% CI 2.34-6.39) OV were independently associated with decompensation. When considering OV status and trajectories, small (HR 2.65, 95% CI 1.39-5.05) and large (HR 4.90, 95% CI 2.49-9.63) OV at baseline and/or follow-up were independently associated with decompensation compared with the absence of OV at baseline and/or follow-up. The presence of either small (HR 2.8, 95% CI 1.16-6.74) or large (HR 5.29, 95% CI 1.96-14.2) OV was also independently associated with incident PVT. Conclusion: In NAFLD-related cACLD, the presence, severity, and evolution of OV stratify the risk of developing decompensation and PVT. Impact and implications: Portal hypertension is the main driver of liver decompensation in chronic liver diseases, and its non-invasive markers can help risk prediction. The presence, severity, and progression of oesophageal varices stratify the risk of complications of non-alcoholic fatty liver disease. Easily obtainable laboratory values and liver stiffness measurement can identify patients at low risk for whom endoscopy may be withheld, and can also stratify the risk of liver-related complications.

Point-of-Care Noninvasive Prediction of Liver-Related Events in Patients With Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Individual risk prediction of liver-related events (LRE) is needed for clinical assessment of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) patients. We aimed to provide point-of-care validated liver stiffness measurement (LSM)-based risk prediction models for the development of LRE in patients with NAFLD, focusing on selecting patients for clinical trials at risk of clinical events. METHODS: Two large multicenter cohorts were evaluated, 2638 NAFLD patients covering all LSM values as the derivation cohort and 679 more advanced patients as the validation cohort. We used Cox regression to develop and validate risk prediction models based on LSM alone, and the ANTICIPATE and ANTICIPATE-NASH models for clinically significant portal hypertension. The main outcome of the study was the rate of LRE in the first 3 years after initial assessment. RESULTS: The 3 predictive models had similar performance in the derivation cohort with a very high discriminative value (c-statistic, 0.87-0.91). In the validation cohort, the LSM-LRE alone model had a significant inferior discrimination (c-statistic, 0.75) compared with the other 2 models, whereas the ANTICIPATE-NASH-LRE model (0.81) was significantly better than the ANTICIPATE-LRE model (0.79). In addition, the ANTICIPATE-NASH-LRE model presented very good calibration in the validation cohort (integrated calibration index, 0.016), and was better than the ANTICIPATE-LRE model. CONCLUSIONS: The ANTICIPATE-LRE models, and especially the ANTICIPATE-NASH-LRE model, could be valuable validated clinical tools to individually assess the risk of LRE at 3 years in patients with NAFLD/NASH.

Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis.

BACKGROUND: Histologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD. METHODS: This was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0-4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score ≥15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0-2 vs F3 vs F4; LSM: <10 vs 10 to <20 vs ≥20 kPa; FIB-4: <1·3 vs 1·3 to ≤2·67 vs >2·67; NFS: <-1·455 vs -1·455 to ≤0·676 vs >0·676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226. FINDINGS: Of 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44·7%] were female, median age was 54 years [IQR 44-63), and 1161 [46·1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33-91], the composite endpoint was observed in 145 (5·8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0·0001 for all comparisons). The tAUC at 5 years were 0·72 (95% CI 0·62-0·81) for histology, 0·76 (0·70-0·83) for LSM-VCTE, 0·74 (0·64-0·82) for FIB-4, and 0·70 (0·63-0·80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression. INTERPRETATION: Simple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases. FUNDING: Innovative Medicines Initiative 2.

Impact of PNPLA3 rs738409 Polymorphism on the Development of Liver-Related Events in Patients With Nonalcoholic Fatty Liver Disease.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) is a complex disease, resulting from the interplay between environmental determinants and genetic variations. Single nucleotide polymorphism rs738409 C>G in the PNPLA3 gene is associated with hepatic fibrosis and with higher risk of developing hepatocellular carcinoma. Here, we analyzed a longitudinal cohort of biopsy-proven NAFLD subjects with the aim to identify individuals in whom genetics may have a stronger impact on disease progression. METHODS: We retrospectively analyzed 756 consecutive, prospectively enrolled biopsy-proven NAFLD subjects from Italy, United Kingdom, and Spain who were followed for a median of 84 months (interquartile range, 65-109 months). We stratified the study cohort according to sex, body mass index (BMI)

Programmed cell death 1 genetic variant and liver damage in nonalcoholic fatty liver disease.

BACKGROUND AND AIMS: Programmed cell death 1/programmed cell death-ligand 1 (PD-1/PDL-1) axis has been reported to modulate liver inflammation and progression to hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD). Here, we examined whether the PDCD1 variation is associated with NAFLD severity in individuals with liver biopsy. METHODS: We examined the impact of PDCD1 gene variants on HCC, as robust severe liver disease phenotype in UK Biobank participants. The strongest genetic association with the rs13023138 G>C variation was subsequently tested for association with liver damage in 2889 individuals who underwent liver biopsy for suspected nonalcoholic steatohepatitis (NASH). Hepatic transcriptome was examined by RNA-Seq in a subset of NAFLD individuals (n = 121). Transcriptomic and deconvolution analyses were performed to identify biological pathways modulated by the risk allele. RESULTS: The rs13023138 C>G showed the most robust association with HCC in UK Biobank (p = 5.28E-4, OR = 1.32, 95% CI [1.1, 1.5]). In the liver biopsy cohort, rs13023138 G allele was independently associated with severe steatosis (OR 1.17, 95% CI 1.02-1.34; p = .01), NASH (OR 1.22, 95% CI 1.09-1.37; p < .001) and advanced fibrosis (OR 1.26, 95% CI 1.06-1.50; p = .007). At deconvolution analysis, rs13023138 G>C allele was linked to higher hepatic representation of M1 macrophages, paralleled by upregulation of pathways related to inflammation and higher expression of CXCR6. CONCLUSIONS: The PDCD1 rs13023138 G allele was associated with HCC development in the general population and with liver disease severity in patients at high risk of NASH.

Noninvasive assessment of liver disease severity in patients with nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes.

BACKGROUND AND AIMS: We evaluated the diagnostic accuracy of simple, noninvasive tests (NITs) in NAFLD patients with type 2 diabetes (T2D). METHODS AND RESULTS: This was an individual patient data meta-analysis of 1780 patients with biopsy-proven NAFLD and T2D. The index tests of interest were FIB-4, NAFLD Fibrosis Score (NFS), aspartate aminotransferase-to-platelet ratio index, liver stiffness measurement (LSM) by vibration-controlled transient elastography, and AGILE 3+. The target conditions were advanced fibrosis, NASH, and fibrotic NASH(NASH plus F2-F4 fibrosis). The diagnostic performance of noninvasive tests. individually or in sequential combination, was assessed by area under the receiver operating characteristic curve and by decision curve analysis. Comparison with 2278 NAFLD patients without T2D was also made. In NAFLD with T2D LSM and AGILE 3+ outperformed, both NFS and FIB-4 for advanced fibrosis (area under the receiver operating characteristic curve:LSM 0.82, AGILE 3+ 0.82, NFS 0.72, FIB-4 0.75, aspartate aminotransferase-to-platelet ratio index 0.68; p < 0.001 of LSM-based versus simple serum tests), with an uncertainty area of 12%-20%. The combination of serum-based with LSM-based tests for advanced fibrosis led to a reduction of 40%-60% in necessary LSM tests. Decision curve analysis showed that all scores had a modest net benefit for ruling out advanced fibrosis at the risk threshold of 5%-10% of missing advanced fibrosis. LSM and AGILE 3+ outperformed both NFS and FIB-4 for fibrotic NASH (area under the receiver operating characteristic curve:LSM 0.79, AGILE 3+ 0.77, NFS 0.71, FIB-4 0.71; p < 0.001 of LSM-based versus simple serum tests). All noninvasive scores were suboptimal for diagnosing NASH. CONCLUSIONS: LSM and AGILE 3+ individually or in low availability settings in sequential combination after FIB-4 or NFS have a similar good diagnostic accuracy for advanced fibrosis and an acceptable diagnostic accuracy for fibrotic NASH in NAFLD patients with T2D.

MAFLD: a multisystem disease.

Nonalcoholic fatty liver disease (NAFLD), affecting about 25% of general population and more than 50% of dysmetabolic patients, is an emerging cause of chronic liver disease and its complications. Recently, an international consensus of experts proposed to rename this disease as 'Metabolic dysfunction-Associated Fatty Liver Disease' (MAFLD) to focus on the bidirectional interplay between fatty liver and metabolic alterations and to stress the need of assessing fatty liver independently from alcohol consumption and other coexisting causes of liver disease. The peculiarity of NAFLD/MAFLD lies in the presence of a higher risk of not only - as expected - liver-related events but also of extrahepatic events, mostly cardiovascular and cancers. Available evidence suggests that these associations are not only the expression of sharing the same risk factors but shed light about the ability of NAFLD/MAFLD and particularly of its progressive form - nonalcoholic/metabolic dysfunction-associated steatohepatitis - to act as an independent risk factor via promotion of atherogenic dyslipidemia and a proinflammatory, profibrogenic, and procoagulant systemic environment. The present review summarizes available epidemiological and clinical evidence supporting the concept of NAFLD/MAFLD as a multisystemic disease, and highlights potential explanatory mechanisms underlying the association between NAFLD/MAFLD and extrahepatic disorders.

AGILE 3+ Score for the Diagnosis of Advanced Fibrosis and for Predicting Liver-related Events in NAFLD.

BACKGROUND & AIMS: We aimed to assess the diagnostic accuracy of AGILE 3+, a recently developed score based on the combination of aspartate aminotransferase/alanine aminotransferase ratio, platelet count, diabetes status, sex, age, and liver stiffness measurement (LSM) by transient elastography, when compared with Fibrosis-4 (FIB-4) and LSM, for the diagnosis of advanced fibrosis and for the prediction of liver-related events (LREs) occurrence in patients with NAFLD. METHODS: A total of 614 consecutive patients with biopsy-proven NAFLD or clinical diagnosis of NAFLD-related compensated cirrhosis were enrolled. LREs were recorded during follow-up. FIB-4, LSM by transient elastography (FibroScan device), and AGILE 3+ were measured. The diagnostic performance of noninvasive criteria for advanced fibrosis and for the prediction of LREs was assessed using the area under the receiver operating characteristic curve (AUROC) and decision curve analysis. RESULTS: In patients with biopsy-proven NAFLD (n = 520), LSM and AGILE 3+ had higher AUROC than FIB-4 (0.88 for LSM and AGILE 3+ vs 0.78 for FIB-4; P < .001) for advanced fibrosis, and AGILE 3+ exhibited a smaller indeterminate area in the test (25.2% for FIB-4 vs 13.1% for LSM vs 8.3% for AGILE 3+). Within the entire cohort of patients, AGILE 3+ had significantly higher AUROC for predicting LREs with respect to LSM (AUROC 36 months 0.95 vs 0.93; P =.008; 60 months 0.95 vs 0.92; P = .006; 96 months 0.97 vs 0.95; P = .001). Decision curve analysis showed that all scores had modest net benefit for ruling-out advanced fibrosis at the risk threshold of 5% to 10% where advanced fibrosis was absent. At the risk threshold of 5% of false negatives or false positives in LRE at 36, 60, 96, and 120 months, AGILE 3+ outperformed both FIB-4 and LSM for ruling out LRE. CONCLUSIONS: Depending on resource availability, clinical setting, and the risk scenarios, AGILE 3+ is an accurate and valid alternative to FIB-4 and LSM for the noninvasive assessment of disease severity and prognosis in patients with NAFLD.

RESIST-HCV Criteria to Monitor Progression of Low-Risk Esophageal Varices in Patients With Compensated Cirrhosis After HCV Eradication: The SIMPLE Study: SIMPLE: Scoring Index to Monitor Progression of Low-risk Esophageal varices.

INTRODUCTION: Noninvasive criteria to predict the progression of low-risk esophageal varices (EV) in patients with compensated hepatitis C virus (HCV) cirrhosis after sustained virological response (SVR) by direct-acting antivirals (DAAs) are lacking. Our aim was to assess the diagnostic performance of Rete Sicilia Selezione Terapia-HCV (RESIST-HCV) criteria for EV progression compared with elastography-based criteria (Baveno VI, Expanded Baveno VI, and Baveno VII-HCV criteria). METHODS: All consecutive patients observed at 3 referral centers with compensated HCV cirrhosis with or without F1 EV who achieved sustained virological response by DAAs were classified at last esophagogastroduodenoscopy (EGDS) as RESIST-HCV low risk (i.e., low probability of high-risk varices [HRV]) if platelets were >120 × 10 9 /L and serum albumin >3.6 g/dL or RESIST-HCV high risk (i.e., high probability of HRV) if platelets were <120 × 10 9 /L or serum albumin <3.6 g/dL. The primary outcome was the progression to HRV. The area under the receiver operating characteristic curve and decision curve analysis of noninvasive criteria were calculated. RESULTS: The cohort consisted of 353 patients in Child-Pugh class A (mean age 67.2 years, 53.8% males). During a mean follow-up of 44.2 months, 34 patients (9.6%, 95% CI 6.7%-13.5%) developed HRV. At the last EGDS, 178 patients (50.4%) were RESIST-low risk, and 175 (49.6%) were RESIST-high risk. RESIST-HCV criteria showed the highest area under the receiver operating characteristic curve (0.70, 95% confidence interval 0.65-0.75), correctly sparing the highest number of EGDS (54.3%), with the lowest false-positive rate (45.7%), compared with elastography-based criteria. Decision curve analysis showed that RESIST-HCV had higher clinical utility than elastography-based criteria. DISCUSSION: Biochemical-based RESIST-HCV criteria are useful to easily predict HRV development after HCV eradication by DAAs in patients with compensated cirrhosis and low-risk EV.

A cholestatic pattern predicts major liver-related outcomes in patients with non-alcoholic fatty liver disease.

BACKGROUND & AIMS: NAFLD patients usually have an increase in AST/ALT levels, but cholestasis can also be observed. We aimed to assess in subjects with NAFLD the impact of the (cholestatic) C pattern on the likelihood of developing major liver-related outcomes (MALO). METHODS: Five hundred and eighty-two consecutive patients with biopsy-proven NAFLD or a clinical diagnosis of NAFLD-related compensated cirrhosis were classified as hepatocellular (H), C and mixed (M) patterns, by using the formula (ALT/ALT Upper Limit of Normal-ULN)/(ALP/ALP ULN). MALO were recorded during follow-up. An external cohort of 1281 biopsy-proven NAFLD patients was enrolled as validation set. RESULTS: H, M and C patterns were found in 153 (26.3%), 272 (46.7%) and 157 (27%) patients respectively. During a median follow-up of 78 months, only 1 (0.6%) patient with H pattern experienced MALO, whilst 15 (5.5%) and 38 (24.2%) patients in M and C groups had MALO. At multivariate Cox regression analysis, age >55 years (HR 2.55, 95% CI 1.17-5.54; p = .01), platelets <150 000/mmc (HR 0.14, 95% CI 0.06-0.32; p < .001), albumin <4 g/L(HR 0.62, 95% CI 0.35-1.08; p = .09), C versus M pattern (HR 7.86, 95% CI 1.03-60.1; p = .04), C versus H pattern(HR 12.1, 95% CI 1.61-90.9; p = .01) and fibrosis F3-F4(HR 35.8, 95% CI 4.65-275.2; p < .001) were independent risk factors for MALO occurrence. C versus M pattern(HR 14.3, 95% CI 1.90-105.6; p = .008) and C versus H pattern (HR 15.6, 95% CI 2.10-115.1; p = .0068) were confirmed independently associated with MALO occurrence in the validation set. The immunohistochemical analysis found a significantly higher prevalence of moderate-high-grade ductular metaplasia combined with low-grade ductular proliferation in C pattern when compared with the biochemical H pattern. Gene expression analysis showed a lower expression of NR1H3, RXRα and VCAM1 in patients with the C pattern. CONCLUSIONS: The presence of a cholestatic pattern in patients with NAFLD predicts a higher risk of MALO independently from other features of liver disease.