Fibrosis progression rate in a systematic review of placebo-treated nonalcoholic steatohepatitis

Recent advances in MASLD genetics: Insights into disease mechanisms and the next frontiers in clinical application

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease in the world and a growing cause of liver-related morbidity and mortality. Yet, at the same time, our understanding of the pathophysiology and genetic underpinnings of this increasingly common yet heterogeneous disease has increased dramatically over the last 2 decades, with the potential to lead to meaningful clinical interventions for patients. We have now seen the first pharmacologic therapy approved for the treatment of MASLD, and multiple other potential treatments are currently under investigation-including gene-targeted RNA therapies that directly extend from advances in MASLD genetics. Here we review recent advances in MASLD genetics, some of the key pathophysiologic insights that human genetics has provided, and the ways in which human genetics may inform our clinical practice in the field of MASLD in the near future.

Metabolic dysfunction-associated steatotic liver disease: a key factor in hepatocellular carcinoma therapy response

The conceptual evolution of non-alcoholic fatty liver disease (NAFLD) to what, since 2023, is called metabolic dysfunction-associated steatotic liver disease (MASLD) not only represents a change in the classification and definition of the disease but also reflects a broader understanding of this heterogeneous condition, which still with many aspects to refine. Although the definition of NAFLD can be interchanged to a high percentage with the new MASLD concept in different aspects, MASLD has been proposed as a relevant factor that influences the response to new immunotherapeutic treatments in the management of MASLD-related hepatocellular carcinoma (HCC), compared to HCC of other etiologies. This indicates that the etiology of HCC plays a relevant role in the prognosis, highlighting the urgency of evaluating treatment regimens for this subgroup of patients in upcoming clinical trials. A better understanding of the pathophysiology of MASLD generates strategies that not only aid in its management but also provide strategies to directly intervene in the carcinogenesis of HCC.

TM6SF2 -rs58542926 Genotype Has Opposing Effects on Incidence of Hepatic and Cardiac Events in a Community Cohort

INTRODUCTION

TM6SF2 -rs58542926-T is associated with increased cirrhosis and modestly decreased coronary artery disease prevalence. However, relative effects of TM6SF2 genotype on major adverse cardiovascular events (MACE) vs liver-related events (LRE) are not known.

METHODS

We used the UK Biobank, a prospective cohort with genetic and inpatient diagnosis data. The primary predictor was TM6SF2 -rs58542926 genotype, and the primary outcomes were MACE and LRE. Effects were reported as subhazard ratios (sHRs) and 10-year cumulative incidence by Fine-Gray competing risk analyses.

RESULTS

More than 430,000 individuals met inclusion criteria. TM6SF2 -rs58542926-TT genotype (vs CC) was associated with higher incidence of LRE (adjusted sHR 3.16, 95% confidence interval 1.86-5.37) and lower incidence of MACE (adjusted sHR for TT vs CC genotype 0.76, 95% confidence interval 0.63-0.91). In individuals with fibrosis-4 (FIB4) < 1.3, 1.3-2.67, and > 2.67, 10-year LRE incidence in TM6SF2 -rs58542926-TT vs CC individuals was 0.08% vs 0.06% ( P > 0.05), 0.81% vs 0.20% ( P < 0.0001), and 10.5% vs 3.4% ( P = 0.00094), respectively. The corresponding values for MACE were 3.8% vs 5.1% ( P = 0.032), 6.4% vs 8.2% ( P = 0.040), and 17.1% vs 12.4% ( P > 0.05). The absolute decrease in MACE with rs58542926-TT (vs CC) genotype exceeded the absolute increase in LRE in all groups but FIB4 > 2.67. Associations of TM6SF2 genotype with LRE/MACE were significant in men but not women. TM6SF2 -rs58542926-T allele was also associated with increased hepatic steatosis and corrected T1 time by magnetic resonance imaging, with greater effect sizes in men than women.

DISCUSSION

TM6SF2 genotype has opposite effects on LRE vs MACE incidence, and absolute effects on MACE were greater except in those with highest FIB4 scores. Effects were strongest in men. These findings clarify implications of TM6SF2 genotype based on personalized clinical risk.

Natural history and progression of metabolic dysfunction-associated steatotic liver disease

The natural history of metabolic dysfunction-associated steatotic liver disease (MASLD), previously referred to as non-alcoholic fatty liver disease (NAFLD), is complex and long. A minority of patients develop inflammation and risk progressive fibrosis that can result in cirrhosis. Progression to cirrhosis occurs in 3-5% of patients and often takes more than 20 years. This narrative review presents an update on the natural history of MASLD, discussing studies and risk estimates for progression to severe outcomes, such as decompensated cirrhosis or hepatocellular carcinoma. We highlight the dynamic progression of liver damage, how to identify patients whose disease progresses over time, and how risk factors might be mitigated to reduce the risk for disease progression.

Clinical cohort of nonalcoholic fatty liver disease in a primary care setting

Background and Aims

Nonalcoholic fatty liver disease (NAFLD) is increasingly common, and primary care physicians (PCPs) are often the first to diagnose NAFLD. While guidelines on NAFLD management in primary care exist, there are limited data on clinical practice patterns.

Approach

We gathered data from over 370,000 patients with at least one PCP visit between July 2016 and September 2023. Using ICD-10 codes to identify patients with a diagnosis of NAFLD or Nonalcoholic Steatohepatitis (NASH), we extracted demographics, comorbidities, laboratory results, prescriptions, imaging orders, and referrals to describe their care.

Results

We identified 10,334 patients with a diagnosis code of NAFLD (93.1%) and/or NASH (16.7%) during a PCP visit. Just over half (54.8%) were female, mean age was 52.8 years, and mean BMI was 33.2 kg/m2 with 90% having overweight or obese. More than 50% had hypertension and hyperlipidemia, and 38% had diabetes. At the diagnosis visit, 2.7% had ultrasound elastography ordered, 2.7% liver biopsy, and less than 1% magnetic resonance elastography. During follow-up ranging from 0 to 7 years, patients had a mean of 15 encounters, during which 4% were diagnosed with fibrosis or cirrhosis. Only 24.2% of patients were referred to a nutritionist and 18% had an appointment, and only 0.7% were referred to hepatology and 3.8% saw a hepatologist.

Conclusion

PCPs have not widely implemented clinical practice guidelines for NAFLD, resulting in suboptimal care including for the substantial minority with fibrosis or cirrhosis. Patients might benefit from targeted NAFLD education for PCPs and improved decision and management support.

Monitoring disease progression in metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common cause of chronic liver disease. Its prevalence is increasing with the epidemic of obesity and metabolic syndrome. MASLD progression into metabolic dysfunction-associated steatohepatitis (MASH) and advanced fibrosis may lead to decompensated cirrhosis and development of liver-related events, hepatocellular carcinoma and death. Monitoring disease progression is critical in decreasing morbidity, mortality, need for transplant and economic burden. Assessing for treatment response once FDA-approved medications are available is still an unmet clinical need.

AIMS

To explore the most up-to-date literature on testing used for monitoring disease progression and treatment response METHODS: We searched PubMed from inception to 15 August 2023, using the following MeSH terms: 'MASLD', 'Metabolic dysfunction-associated steatotic liver disease', 'MASH', 'metabolic dysfunction-associated steatohepatitis', 'Non-Alcoholic Fatty Liver Disease', 'NAFLD', 'non-alcoholic steatohepatitis', 'NASH', 'Biomarkers', 'clinical trial'. Articles were also identified through searches of the authors' files. The final reference list was generated based on originality and relevance to this review's broad scope, considering only papers published in English.

RESULTS

We have cited 101 references in this review detailing methods to monitor MASLD disease progression and treatment response.

CONCLUSION

Various biomarkers can be used in different care settings to monitor disease progression. Further research is needed to validate noninvasive tests more effectively.

Surveillance of the liver in type 2 diabetes: important but unfeasible?

Fatty liver plays a pivotal role in the pathogenesis of the metabolic syndrome and type 2 diabetes. According to an updated classification, any individual with liver steatosis and one or more features of the metabolic syndrome, without excess alcohol consumption or other known causes of steatosis, has metabolic dysfunction-associated steatotic liver disease (MASLD). Up to 60-70% of all individuals with type 2 diabetes have MASLD. However, the prevalence of advanced liver fibrosis in type 2 diabetes remains uncertain, with reported estimates of 10-20% relying on imaging tests and likely overestimating the true prevalence. All stages of MASLD impact prognosis but fibrosis is the best predictor of all-cause and liver-related mortality risk. People with type 2 diabetes face a two- to threefold increase in the risk of liver-related death and hepatocellular carcinoma, with 1.3% progressing to severe liver disease over 7.7 years. Because reliable methods for detecting steatosis are lacking, MASLD mostly remains an incidental finding on imaging. Regardless, several medical societies advocate for universal screening of individuals with type 2 diabetes for advanced fibrosis. Proposed screening pathways involve annual calculation of the Fibrosis-4 (FIB-4) index, followed by a secondary test such as transient elastography (TE) for intermediate-to-high-risk individuals. However, owing to unsatisfactory biomarker specificity, these pathways are expected to channel approximately 40% of all individuals with type 2 diabetes to TE and 20% to tertiary care, with a false discovery rate of up to 80%, raising concerns about feasibility. There is thus an urgent need to develop more effective strategies for surveying the liver in type 2 diabetes. Nonetheless, weight loss through lifestyle changes, pharmacotherapy or bariatric surgery remains the cornerstone of management, proving highly effective not only for metabolic comorbidities but also for MASLD. Emerging evidence suggests that fibrosis biomarkers may serve as tools for risk-based targeting of weight-loss interventions and potentially for monitoring response to therapy.

Proactive case finding of alcohol-related liver disease in high-risk populations: A systematic review

BACKGROUND

Alcohol-related liver disease (ARLD) is often diagnosed at a late stage when mortality is unacceptably high. Earlier identification of ARLD may lead to reduced alcohol intake, participation in hepatocellular carcinoma surveillance and reduction in liver-related morbidity and mortality. People with alcohol use disorder (AUD) are at highest risk of ARLD. The aim of this systematic review was to understand the yield of proactive screening for ARLD amongst high-risk groups.

METHODS

Embase, Medline, Scopus and grey literature were searched for studies describing proactive assessment for alcohol-related liver disease in people with a history of alcohol excess or diagnosed AUD. Outcomes of interest were fibrosis and cirrhosis detection rates, clinical outcomes, portal hypertension evaluation, attendance at follow-up and cost-effectiveness.

RESULTS

Fifteen studies were identified for inclusion from 1115 returned by the search. Four key settings for patient engagement were identified as inpatient addiction services, outpatient addiction services, general acute hospital admissions and community outreach. Of these, acute hospital admissions were the highest yield for cirrhosis at 10.8%-29.6% and community outreach the lowest was 1.2%-2.3%.

CONCLUSIONS

Targeted fibrosis assessment of high-risk populations for ARLD is feasible to conduct and identifies a proportion of patients at risk of advanced liver disease. The highest yield is amongst inpatients admitted with AUD. Prospective work is needed to establish which are the most effective and acceptable screening methods and the impact on long-term outcomes.

A natural language processing algorithm accurately classifies steatotic liver disease pathology to estimate the risk of cirrhosis

BACKGROUND

Histopathology remains the gold standard for diagnosing and staging metabolic dysfunction-associated steatotic liver disease (MASLD). The feasibility of studying MASLD progression in electronic medical records based on histological features is limited by the free-text nature of pathology reports. Here we introduce a natural language processing (NLP) algorithm to automatically score MASLD histology features.

METHODS

From the Mass General Brigham health care system electronic medical record, we identified all patients (1987-2021) with steatosis on index liver biopsy after excluding excess alcohol use and other etiologies of liver disease. An NLP algorithm was constructed in Python to detect steatosis, lobular inflammation, ballooning, and fibrosis stage from pathology free-text and manually validated in >1200 pathology reports. Patients were followed from the index biopsy to incident decompensated liver disease accounting for covariates.

RESULTS

The NLP algorithm demonstrated positive and negative predictive values from 93.5% to 100% for all histologic concepts. Among 3134 patients with biopsy-confirmed MASLD followed for 20,604 person-years, rates of the composite endpoint increased monotonically with worsening index fibrosis stage (p for linear trend <0.005). Compared to simple steatosis (incidence rate, 15.06/1000 person-years), the multivariable-adjusted HRs for cirrhosis were 1.04 (0.72-1.5) for metabolic dysfunction-associated steatohepatitis (MASH)/F0, 1.19 (0.92-1.54) for MASH/F1, 1.89 (1.41-2.52) for MASH/F2, and 4.21 (3.26-5.43) for MASH/F3.

CONCLUSIONS

The NLP algorithm accurately scores histological features of MASLD from pathology free-text. This algorithm enabled the construction of a large and high-quality MASLD cohort across a multihospital health care system and disclosed an accelerating risk for cirrhosis based on the index MASLD fibrosis stage.

Antifibrotic therapy in nonalcoholic steatohepatitis: time for a human-centric approach

Nonalcoholic steatohepatitis (NASH) might soon become the leading cause of end-stage liver disease and indication for liver transplantation worldwide. Fibrosis severity is the only histological predictor of liver-related morbidity and mortality in NASH identified to date. Moreover, fibrosis regression is associated with improved clinical outcomes. However, despite numerous clinical trials of plausible drug candidates, an approved antifibrotic therapy remains elusive. Increased understanding of NASH susceptibility and pathogenesis, emerging human multiomics profiling, integration of electronic health record data and modern pharmacology techniques hold enormous promise in delivering a paradigm shift in antifibrotic drug development in NASH. There is a strong rationale for drug combinations to boost efficacy, and precision medicine strategies targeting key genetic modifiers of NASH are emerging. In this Perspective, we discuss why antifibrotic effects observed in NASH pharmacotherapy trials have been underwhelming and outline potential approaches to improve the likelihood of future clinical success.

Community pathways for the early detection and risk stratification of chronic liver disease: a narrative systematic review

Patients with chronic liver disease are often diagnosed during an index presentation to hospital with decompensated cirrhosis or liver-related events, and these presentations are associated with high mortality. However, there is often a long asymptomatic phase, in which there is an opportunity for earlier diagnosis and interventions to prevent progression to advanced disease. Therefore, strategies for early diagnosis and interventions (including behavioural changes and pharmacological treatments) that prevent patients progressing to cirrhosis and its associated complications probably have substantial benefits for patients and health-care services. Many community pathways have been generated. Some pathways focus on abnormal liver function tests as a starting point to diagnose liver disease. Other pathways target groups at greater risk of chronic liver disease-particularly people with harmful alcohol consumption, type 2 diabetes, and obesity. This systematic review summarises the existing strategies available for the early detection or risk stratification of liver disease, focusing primarily on alcohol-related liver disease and non-alcoholic fatty liver disease. Conducting randomised clinical trials that compare different strategies will be essential to elucidate which pathways are acceptable to patients, feasible, provide high diagnostic accuracy for the detection of liver disease, improve liver-related outcomes, and are most cost-effective at the population level.

Vibration-controlled Transient Elastography for Assessment of Liver Fibrosis at a USA Academic Medical Center

Background and Aims

Vibration-controlled transient elastography (VCTE) is a noninvasive tool that uses liver stiffness measurement (LSM) to assess fibrosis. Since real-life data during everyday clinical practice in the USA are lacking, we describe the patterns of use and diagnostic performance of VCTE in patients at an academic medical center in New York City.

Methods

Patients who received VCTE scans were included if liver biopsy was performed within 1 year. Diagnostic performance of VCTE in differentiating dichotomized fibrosis stages was assessed via area under the receiver operating characteristics (AUROC). Fibrosis stage determined from VCTE LSM was compared to liver biopsy.

Results

Of 109 patients, 49 had nonalcoholic fatty liver disease, 16 chronic hepatitis C, 15 congestive hepatopathy, and 22 at least two etiologies. AUROC was 0.90 for differentiating cirrhosis (stage 4) with a positive predictive value (PPV) range of 0.28 to 0.45 and negative predictive value range of 0.96 to 0.98. For 31 (32%) patients, VCTE fibrosis stage was at least two stages higher than liver biopsy fibrosis stage. Thirteen of thirty-five patients considered to have cirrhosis by VCTE had stage 0 to 2 and 12 stage 3 fibrosis on liver biopsy.

Conclusions

VCTE has reasonable diagnostic accuracy and is reliable at ruling out cirrhosis. However, because of its low PPV, caution must be exercised when used to diagnose cirrhosis, as misdiagnosis can lead to unnecessary health care interventions. In routine practice, VTCE is also sometimes performed for disease etiologies for which it has not been robustly validated.

The Placebo Response in Randomized Trials in Nonalcoholic Steatohepatitis Simply Explained

BACKGROUND & AIMS

Liver histology is the primary endpoint in phase III trials in nonalcoholic steatohepatitis (NASH). There is an appreciable response to placebo that confounds endpoint assessment. The aim of this study was to quantify contributors to the placebo response and its impact on liver fibrosis improvement.

METHODS

Estimates of fibrosis improvement in placebo-treated participants were made using probabilistic simulation. Each simulated trial included 120 participants. Parameters considered in the model included sampling and observer variability, regression to the mean, and net fibrosis progression calibrated to reported trial outcomes.

RESULTS

In large phase IIb and III trials, 22% of placebo-treated participants with fibrosis stage 2 or 3 NASH at baseline improved by at least 1 fibrosis stage with minimal net disease progression. Estimates of sampling and observer variability in simultaneous biopsy studies highlighted an imbalance where apparent fibrosis improvement was more likely than worsening. Using these estimates and known trial outcomes, net fibrosis progression was estimated at 0.05 stages per year. Simulations of the placebo response rate showed a rate of 22% with 80% of trials falling between 15 and 30%, in keeping with trials reported to date. Additional increases in observer variability further increased the placebo response.

CONCLUSIONS

The analyses presented simply define the placebo response in liver fibrosis in trials in NASH in terms of sampling and observer variability, regression to the mean, and fibrosis progression. Factors relating to liver biopsy are largely unmodifiable, and the variation in placebo response rates, both simulated and observed, challenges the role of biopsy in trial endpoint assessment.

Drug Therapy for Non-Alcoholic Steatohepatitis-Induced Liver Fibrosis

Aim. An overview of current pharmacotherapy for non-alcoholic steatohepatitis (NASH)-associated liver fibrosis.

Key points. In current clinical recommendations, therapeutic measures in non-alcoholic fatty liver disease should include lifestyle change, body weight normalisation, NASH-associated liver fibrosis-specific drug therapy and treatment for metabolic syndrome-related diseases. Given a lack of approved antifibrotic therapies in NASH, several drugs have nevertheless demonstrated an adequate efficacy and safety in phase 3 clinical trials, also in compensated cirrhosis, which allows their practical validation in phase 4.

Conclusion. The understanding of liver fibrosis as an adverse natural consequence of non-alcoholic fatty liver disease clearly attests for an early introduction and wide use of antifibrotic therapy to improve NASH outcomes and avoid associated complications.

 

Systematic review and meta-analysis: analysis of variables influencing the interpretation of clinical trial results in NAFLD

BACKGROUND

NAFLD clinical trials have shown suboptimal results, particularly for liver fibrosis, despite the robust preclinical drug development. We aimed to assess the histological response after the experimental treatment versus placebo by carrying out a meta-analysis of NAFLD clinical trials.

METHODS

After a systematic review of NAFLD clinical trials to May 2021, applying strict selection criteria, the following primary outcomes were observed: (a) NASH resolution, with no worsening of fibrosis when available; (b) fibrosis improvement  ≥ 1 stage, with no worsening of NAS when available; (c) worsening of NAS; (d) worsening of liver fibrosis  ≥ 1 stage, including the progression to cirrhosis on histopathology. Other histological, clinical, and biochemical outcomes were considered secondary endpoints. Heterogeneity was explored by subgroup and sensitivity analyses, and univariable meta-regression.

RESULTS

Twenty-seven randomized clinical trials were included. The pooled efficacy for NASH resolution receiving experimental therapy was 19% (95%CI 15-23; I² 96.2%) compared with placebo 10% (95%CI 7-12; I² 85.8%) (OR 1.66 (95%CI 1.24-2.21); I² 57.8%), while it was 26% (95%CI 22-29); I² 90%)) versus 18% (95%CI 15-21; I² 59%)) for fibrosis improvement (OR 1.34 (95%CI 1.13-1.58); I² 25.4%). For these outcomes, the therapy showed higher efficacy in trials longer than 48 weeks, with  < 60% of diabetic population, and when it targeted FXR, PPAR, and antidiabetic mechanisms, and with a NAS  < 5 for NASH resolution. Also, NASH (OR 0.57 (95%CI 0.39-0.84); I² 67%) and fibrosis worsening (OR 0.65 (95%CI 0.46-0.92); I² 61.9%) were prevented with the therapy.

CONCLUSION

This meta-analysis provides information about the efficacy of the therapy versus placebo by comparing different and combined trial outcomes such as NASH resolution, fibrosis improvement, and NAS and fibrosis worsening. Changes in the experimental design and selection criteria of the clinical trials might be suitable to increase the efficacy.