A genetic hypothesis for burnt-out steatohepatitis

From "Burnt-Out" to "Burning-Out": Capturing Liver Fat Loss in Patients With Advanced Metabolic Dysfunction-Associated Steatotic Liver Disease From a Dynamic Perspective

BACKGROUND AND AIMS

The absence of hepatic fat in advanced fibrosis has been documented in metabolic dysfunction-associated steatotic liver disease (''burnt-out" MASLD). However, whether hepatic fat loss occurs continuously with fibrosis progression is controversial. We proposed a "burning-out" concept to describe this process and analyze the long-term outcomes of "burnt-out" and "burning-out" MASLD.

METHODS

We included a MASLD cohort from 16 centers, including 3273 individuals with baseline histology and 5455 with serial vibration-controlled transient elastography measurements during the follow-up. "Burnt-out" MASLD was defined by steatosis grade ≤S1 and fibrosis stage ≥F3. Trajectory analysis identified "burning-out" patients with continuous trends of decreasing controlled attenuation parameter and increasing liver stiffness measurement values.

RESULTS

Of 3273 patients with histologic evaluation included, 435 had "burnt-out" MASLD. Compared with those with pronounced steatosis in advanced fibrosis, patients with "burnt-out" had higher risks of all-cause mortality (hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.14-4.02), liver-related events (LREs; HR, 1.77; 95% CI, 1.12-2.78), and hepatic decompensation (HR, 1.83; 95% CI, 1.11-3.01). Of 5455 patients with vibration-controlled transient elastography included for trajectory analysis, 176 were identified as "burning-out" MASLD. The incidence rates of all-cause mortality, LREs, and decompensation were 7.28, 26.47, and 21.92 per 1000 person-years in "burning-out" patients, respectively. The "burning-out" group had higher cumulative incidences of adverse outcomes than patients with consistently high controlled attenuation parameter and moderate/low liver stiffness measurement values (P < .0001).

CONCLUSIONS

Continuous hepatic fat loss accompanied by fibrosis progression, referred to as "burning-out," was observed in advanced MASLD and associated with high rates of all-cause mortality, LREs, and hepatic decompensation.

Type 2 Diabetes and Hypertension as Risk Factors for Advanced Fibrosis in Biopsy Proven Metabolic Dysfunction-Associated Steatotic Liver Disease

OBJECTIVES

To identify the diagnostic criteria for metabolic dysfunction-associated steatotic liver disease (MASLD) related to liver fibrosis and to characterize patients with cryptogenic steatotic liver disease (SLD) (non-MASLD) among those previously diagnosed with nonalcoholic fatty liver disease (NAFLD).

METHODS

This multicenter retrospective study included 511 patients diagnosed with NAFLD via liver biopsy, and the prevalence of MASLD was assessed based on the diagnostic criteria. Patients were divided into those who met the MASLD criteria and those who did not, and the characteristics of advanced fibrosis and associated cardiometabolic factors were evaluated.

RESULTS

Of the 475 patients with NAFLD, 458 (96.4%) met the criteria for MASLD, showing a high overlap between classical NAFLD and MASLD populations. Severe fibrosis was observed, regardless of the number of cardiometabolic factors. Hypertension and diabetes mellitus significantly contributed to advanced fibrosis (≥ F3), with odds ratio of 1.92 and 2.00 (95% confidence interval of 1.17-3.16 and 1.22-3.28, respectively; both p < 0.01) on multivariate analysis. The other seventeen (3.6%) patients did not meet the diagnostic criteria for MASLD. Among them, seven had significant fibrosis and a high fibrosis-4 index.

CONCLUSIONS

Diabetes mellitus and hypertension are key metabolic factors associated with advanced fibrosis. Some cases, classified as cryptogenic SLD, also exhibit significant fibrosis. Consequently, identifying high-risk patients, including those undergoing noninvasive tests for fibrosis, is crucial.

The contribution of genetics and epigenetics to MAFLD susceptibility

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common liver disease worldwide. The risk of developing MAFLD varies among individuals, due to a combination of environmental inherited and acquired genetic factors. Genome-wide association and next-generation sequencing studies are leading to the discovery of the common and rare genetic determinants of MAFLD. Thanks to the great advances in genomic technologies and bioinformatics analysis, genetic and epigenetic factors involved in the disease can be used to develop genetic risk scores specific for liver-related complications, which can improve risk stratification. Genetic and epigenetic factors lead to the identification of specific sub-phenotypes of MAFLD, and predict the individual response to a pharmacological therapy. Moreover, the variant transcripts and protein themselves represent new therapeutic targets. This review will discuss the current status of research into genetic as well as epigenetic modifiers of MAFLD development and progression.

Impact of clonal hematopoiesis of indeterminate potential on hepatocellular carcinoma in individuals with steatotic liver disease

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global epidemic and is the most rapidly rising cause of HCC. Clonal hematopoiesis of indeterminate potential (CHIP) contributes to neoplastic and cardiometabolic disorders and is considered a harbinger of tissue inflammation. CHIP was recently associated with increased risk of liver disease. The aim of this study was to examine whether CHIP is associated with HCC development in patients with SLD.

APPROACH AND RESULTS

We considered individuals with MASLD-HCC (n=208) and controls with (n =414) and without (n =259) advanced fibrosis who underwent whole exome sequencing. CHIP was diagnosed when ≥2 variant callers identified a known myeloid mutation with variant allele frequency ≥2%. CHIP was observed in 116 participants (13.1%), most frequently in DNMT3A, TET2, TP53 , and ASXL1 , and correlated with age ( p <0.0001) and advanced liver fibrosis (p=0.001). Higher aspartate aminotransferase levels predicted non- DNMT3A -CHIP, in particular with variant allele frequency ≥10% (OR: 1.14, 1.03 -1.28 and OR: 1.30, 1.12 -1.49, respectively, p <0.05). After adjustment for sex, diabetes, and a polygenic risk, a score of inherited MASLD predisposition CHIP was associated with cirrhosis (2.00, 1.30 -3.15, p =0.02), and with HCC even after further adjustment for cirrhosis (OR: 1.81, 1.11 -2.00, 1.30 -3.15, p =0.002). Despite the strong collinearity among aging and development of CHIP and HCC, non- DNTM3A -CHIP, and TET2 lesions remained associated with HCC after full correction for clinical/genetics covariates and age (OR: 2.45, 1.35 -4.53; OR: 4.8, 1.60 -17.0, p =0.02).

CONCLUSIONS

We observed an independent association between CHIP, particularly related to non- DNTM3A and TET2 genetic lesions and MASLD-HCC.

Editorial: Paradox of liver fat content in the spectrum of non-alcoholic fatty liver disease

This article is linked to Loomba et al paper. To view this article, visit https://doi.org/10.1111/apt.17783

Low liver fat in non-alcoholic steatohepatitis-related significant fibrosis and cirrhosis is associated with hepatocellular carcinoma, decompensation and mortality

BACKGROUND

Progression to cirrhosis in non-alcoholic steatohepatitis (NASH) is associated with a decrease in liver fat. However, the prognostic significance of liver fat content in NASH-related significant fibrosis and cirrhosis is unclear.

AIM

To investigate the risk of decompensation, hepatocellular carcinoma (HCC) and mortality stratified by liver fat content in NASH-related significant fibrosis and cirrhosis.

METHODS

In this meta-analysis of individual participant data, 456 patients with both magnetic resonance elastography (MRE) and MRI-derived protein density fat fraction (MRI-PDFF) were enrolled, and 296 patients with longitudinal follow-up were analysed. MRE combined with fibrosis-4 (MEFIB-index), and MRI-PDFF were used to measure liver fibrosis and fat, respectively. MEFIB-negative, MEFIB-positive+ MRI-PDFF ≥5% and MEFIB-positive+ MRI-PDFF <5% were defined as no significant liver fibrosis, NASH with significant fibrosis and higher liver fat content, and NASH with significant fibrosis and low liver fat content groups, respectively. The primary outcome was hepatic decompensation, HCC and death.

RESULTS

The rates of decompensation, HCC and mortality were highest in the NASH with significant fibrosis and low liver fat group (33%, 17% and 17%, respectively), followed by the NASH with significant fibrosis and higher liver fat group (18%, 13% and 13% respectively), and lowest in the no significant fibrosis (MEFIB-negative) group (0%, 1% and 2% respectively). In multivariable-adjusted analysis, low liver fat content was strongly associated (HR = 42.2 [95% CI: 7.5-235.5, p < 0.0001]) with HCC, decompensation and death. Sensitivity analyses for patients with cirrhosis (MRE ≥5 kPa) determined consistent findings.

CONCLUSIONS

Low liver fat content in patients with burnt-out NASH-related significant fibrosis and cirrhosis is associated with an increase in hepatic decompensation, HCC and mortality.

Synthesized HMGB1 peptide prevents the progression of inflammation, steatosis, fibrosis, and tumor occurrence in a non-alcoholic steatohepatitis mouse model

AIM

Non-alcoholic steatohepatitis (NASH) with fibrosis eventually leads to cirrhosis and hepatocellular carcinoma. Thus, the development of therapies other than dietary restriction and exercise, particularly those that suppress steatosis and fibrosis of the liver and have a long-term beneficial effect, is necessary. We aimed to evaluate the therapeutic effects of the HMGB1 peptide synthesized from box A using the melanocortin-4 receptor-deficient (Mc4r-KO) NASH model mouse.

METHODS

We performed short- and long-term administration of this peptide and evaluated the effects on steatosis, fibrosis, and carcinogenesis using Mc4r-KO mice. We also analyzed the direct effect of this peptide on macrophages and hepatic stellate cells in vitro and performed lipidomics and metabolomics techniques to evaluate the effect.

RESULTS

Although this peptide did not show direct effects on macrophages and hepatic stellate cells in vitro, in the short-term administration model, we could confirm the reduction of liver damage, steatosis, and fibrosis progression. The results of lipidomics and metabolomics suggested that the peptide might ameliorate NASH by promoting lipolysis via the activation of fatty acid β-oxidation and improving insulin resistance. In the long-term administration model, this peptide prevented progression to cirrhosis but retained the steatosis state, that is, the peptide prevents the progression to "burnt-out NASH." This peptide inhibited carcinogenesis by about one-third.

CONCLUSION

This HMGB1 peptide can reduce liver damage, improve fibrosis and steatosis, and inhibit carcinogenesis, suggesting that the peptide would be a new treatment candidate for NASH and can contribute to the long-term prognosis for patients with NASH.

Tumorigenesis from non-alcoholic steatohepatitis to hepatocellular carcinoma

Non-alcoholic steatohepatitis (NASH) with metabolic syndrome is increasing to be a main cause of hepatocellular carcinoma (HCC). However, the mechanism of tumorigenesis in NASH induced HCC is still not clear. In this perspective, we will discuss the recent progress that has been made to understand the genetic change and the immune microenvironment of HCC, and the remaining questions. Based on the current study, NASH-HCC is likely to have novel mechanism, which needs more investigation in future.

Nonalcoholic Steatohepatitis (NASH) and Atherosclerosis: Explaining Their Pathophysiology, Association and the Role of Incretin-Based Drugs

Nonalcoholic steatohepatitis (NASH) is the most severe manifestation of nonalcoholic fatty liver disease (NAFLD), a common complication of type 2 diabetes, and may lead to cirrhosis and hepatocellular carcinoma. Oxidative stress and liver cell damage are the major triggers of the severe hepatic inflammation that characterizes NASH, which is highly correlated with atherosclerosis and coronary artery disease. Regarding drug therapy, research on the role of GLP-1 analogues and DPP4 inhibitors, novel classes of antidiabetic drugs, is growing. In this review, we outline the association between NASH and atherosclerosis, the underlying molecular mechanisms, and the effects of incretin-based drugs, especially GLP-1 RAs, for the therapeutic management of these conditions.