ADAPT: An Algorithm Incorporating PRO-C3 Accurately Identifies Patients With NAFLD and Advanced Fibrosis

Determining a healthy reference range and factors potentially influencing PRO-C3 - A biomarker of liver fibrosis

BACKGROUND & AIMS

Progressive fibrosis has been identified as the major predictor of mortality in patients with non-alcoholic fatty liver disease (NAFLD). Several biomarkers are currently being evaluated for their ability to substitute the liver biopsy as the reference standard. Recent clinical studies in NAFLD/NASH patients support the utility of PRO-C3, a marker of type III collagen formation, as a marker for the degree of fibrosis, disease activity, and effect of treatment. Here we establish the healthy reference range, optimal sample handling conditions for both short- and long-term serum storage, and robustness for the PRO-C3 assay.

METHODS

PRO-C3 was measured in 269 healthy volunteers and in 222 NAFLD patients. Robustness of the PRO-C3 assay was measured according to Clinical and Laboratory Standards Institute standards and included validation of interference, precision, and reagent stability, whilst sample stability was defined for storage at different temperatures and for 3 freeze-thaw cycles. Fibrosis scoring was based on histological assessments and used as a reference for the diagnostic ability of PRO-C3 to discriminate between patients with different levels of fibrosis.

RESULTS

Robustness of the PRO-C3 analysis validated by interference, precision, and reagent stability was found to be within the predefined acceptance criteria. The healthy reference range was determined to be 6.1-14.7 ng/ml. Levels of PRO-C3 were not affected by sex, age, BMI, or ethnicity. Levels of PRO-C3 were able to identify patients with clinically significant fibrosis and advanced fibrosis (AUC = 0.83 (95% CI [0.77-0.88], p <0.0001), and AUC = 0.79 (95% CI [0.73-0.85], p <0.0001), respectively).

CONCLUSIONS

The assay proved to be robust and sample stability was found to comply with hospital sample handling requirements. PRO-C3 measured in samples from patients with NAFLD/NASH was diagnostic for significant and advanced liver fibrosis.

LAY SUMMARY

We showed that PRO-C3 levels were stable under conditions conforming with hospital sample-handling requirements. We determined a healthy reference range and showed that PRO-C3 levels were not associated with sex, age, BMI, or ethnicity. Finally, we provide further evidence of an association of PRO-C3 with increasing liver fibrosis.

Incorporating fatty liver disease in multidisciplinary care and novel clinical trial designs for patients with metabolic diseases

With the global epidemics of obesity and associated conditions, including type 2 diabetes, metabolic dysfunction-associated fatty liver disease, chronic kidney disease, hypertension, stroke, cardiovascular disease, osteoporosis, cancer, and cognitive changes, the prevalence of multimorbidity is rapidly increasing worldwide. In this Review, a panel of international experts from across the spectrum of metabolic diseases come together to identify the challenges and provide perspectives on building a framework for a virtual primary care-driven, patient-centred, multidisciplinary model to deliver holistic care for patients with metabolic dysfunction-associated fatty liver disease and associated metabolic diseases. We focus on clinical care and innovative trial design for metabolic dysfunction-associated fatty liver disease and associated metabolic diseases. This work represents a call to action to promote collaboration and partnerships between stakeholders for improving the lives of people with, or at risk of, metabolic dysfunction-associated fatty liver disease and associated metabolic diseases.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has a global prevalence of 25% and is a leading cause of cirrhosis and hepatocellular carcinoma. NAFLD encompasses a disease continuum from steatosis with or without mild inflammation (non-alcoholic fatty liver), to non-alcoholic steatohepatitis (NASH), which is characterised by necroinflammation and faster fibrosis progression than non-alcoholic fatty liver. NAFLD has a bidirectional association with components of the metabolic syndrome, and type 2 diabetes increases the risk of cirrhosis and related complications. Although the leading causes of death in people with NAFLD are cardiovascular disease and extrahepatic malignancy, advanced liver fibrosis is a key prognostic marker for liver-related outcomes and overall mortality, and can be assessed with combinations of non-invasive tests. Patients with cirrhosis should be screened for hepatocellular carcinoma and oesophageal varices. There is currently no approved therapy for NAFLD, although several drugs are in advanced stages of development. Because of the complex pathophysiology and substantial heterogeneity of disease phenotypes, combination treatment is likely to be required for many patients with NAFLD. Healthy lifestyle and weight reduction remain crucial to the prevention and treatment of NAFLD.

Effects of Cotadutide on Metabolic and Hepatic Parameters in Adults With Overweight or Obesity and Type 2 Diabetes: A 54-Week Randomized Phase 2b Study

OBJECTIVE

Cotadutide, a dual GLP-1 and glucagon receptor agonist, is under development for nonalcoholic steatohepatitis (NASH) and chronic kidney disease with type 2 diabetes. The effects of cotadutide on hepatic and metabolic parameters were evaluated in participants with overweight/obesity and type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this phase 2b study, 834 adults with BMI ≥25 kg/m² and type 2 diabetes inadequately controlled with metformin (glycated hemoglobin A_1c [HbA_1c] of 7.0%-10.5% [53-91 mmol/mol]) were randomized to double-blind cotadutide 100 μg (n = 100), 200 μg (n = 256), or 300 μg (n = 256); placebo (n = 110); or open-label liraglutide 1.8 mg (n = 110)-all administered subcutaneously. Coprimary end points were changes in HbA_1c and body weight at week 14. The originally randomized interventions were continued to week 54. Liver damage biomarkers and liver fibrosis algorithms were assessed.

RESULTS

Cotadutide significantly decreased HbA_1c and body weight at weeks 14 and 54 versus placebo (all P < 0.001). Improvements in lipid profile, AST and ALT levels, propeptide of type III collagen level, fibrosis-4 index, and nonalcoholic fatty liver disease fibrosis score were observed with cotadutide 300 μg versus placebo, but not with liraglutide. Weight loss with cotadutide 200 μg was similar to that with liraglutide 1.8 mg and greater with cotadutide 300 μg versus liraglutide 1.8 mg. The most common adverse events with cotadutide (nausea, 35%; vomiting, 17%) decreased over time.

CONCLUSIONS

Cotadutide treatment for 54 weeks improved glycemic control and weight loss in participants with overweight/obesity and type 2 diabetes. Ad hoc analyses demonstrated improvements in hepatic parameters and support further evaluation of cotadutide in NASH.

Valoración bioquímica en la enfermedad hepática grasa asociada a la disfunción metabólica

La enfermedad hepática grasa asociada a la disfunción metabólica (MAFLD) se define por el acúmulo de grasa en el hígado en presencia de alteraciones metabólicas. Suele cursar de forma asintomática y puede progresar a formas graves de enfermedad hepática, ligadas a la aparición de inflamación y/o fibrosis. Su prevalencia es muy elevada (26%), resultando en un alto número de pacientes con riesgo de presentar una enfermedad hepática avanzada. El presente documento describe los marcadores serológicos más relevantes en la caracterización y diagnóstico de la MAFLD, y se propone un ejemplo de su integración en un algoritmo diagnóstico en práctica clínica habitual. En la actualidad se dispone de índices serológicos útiles en el manejo de los pacientes con MAFLD, especialmente en la estratificación del riesgo de la presencia fibrosis. Una gran parte de la población está en riesgo de desarrollar enfermedad hepática grave. La integración de los marcadores serológicos no invasivos en la estratificación del riesgo de fibrosis hepática puede contribuir a un mejor control y manejo de los pacientes con MAFLD.

Biochemical assessment of metabolic associated fatty liver disease

Metabolic-associated fatty liver disease (MAFLD) is defined as fat accumulation in the liver in the presence of metabolic alterations. This disorder is generally asymptomatic and may progress to severe liver disease, which are linked to inflammation and/or fibrosis. MAFLD has a high prevalence (26%) and therefore a considerable number of patients are at high risk of having advanced liver disease. This document provides an overview of the most relevant serological markers in the characterization and diagnosis of MAFLD. An example is provided of a routine diagnostic algorithm that incorporates serological testing. A range of useful serological scores are currently available for the management of MAFLD patients, especially for the stratification of patients at risk of fibrosis. A large proportion of the population is at risk of developing severe liver disease. The integration of non-invasive serological markers in the stratification of patients at risk for liver fibrosis may contribute to improve the control and management of MAFLD patients.

Machine learning algorithm outperforms fibrosis markers in predicting significant fibrosis in biopsy-confirmed NAFLD

BACKGROUND

The presence of significant liver fibrosis is a key determinant of long-term prognosis in non-alcoholic fatty liver disease (NAFLD). We aimed to develop a novel machine learning algorithm (MLA) to predict fibrosis severity in NAFLD and compared it with the most widely used non-invasive fibrosis biomarkers.

METHODS

We used a cohort of 553 adults with biopsy-proven NAFLD, who were randomly divided into a training cohort (n = 278) for the development of both logistic regression model (LRM) and MLA, and a validation cohort (n = 275). Significant fibrosis was defined as fibrosis stage F ≥ 2. MLA and LRM were derived from variables that were selected using a least absolute shrinkage and selection operator (LASSO) logistic regression algorithm.

RESULTS

In the training cohort, the variables selected by LASSO algorithm were body mass index, pro-collagen type III, collagen type IV, aspartate aminotransferase and albumin-to-globulin ratio. The diagnostic accuracy of MLA showed the highest values of area under the receiver operator characteristic curve (AUROC: 0.902, 95% CI 0.869-0.904) for identifying fibrosis F ≥ 2. The LRM AUROC was 0.764, 95% CI 0.710-0.816 and significantly better than the AST-to-Platelet ratio (AUROC 0.684, 95% CI 0.605-0.762), FIB-4 score (AUROC 0.594, 95% CI 0.503-0.685) and NAFLD Fibrosis Score (AUROC 0.557, 95% CI 0.470-0.644). In the validation cohort, MLA also showed the highest AUROC (0.893, 95% CI 0.864-0.901). The diagnostic accuracy of MLA outperformed that of LRM in all subgroups considered.

CONCLUSIONS

Our newly developed MLA algorithm has excellent diagnostic performance for predicting fibrosis F ≥ 2 in patients with biopsy-confirmed NAFLD.

A Sequential Algorithm Combining ADAPT and Liver Stiffness Can Stage Metabolic-Associated Fatty Liver Disease in Hospital-Based and Primary Care Patients

INTRODUCTION

Metabolic-associated fatty liver disease is common, with fibrosis the major determinant of adverse outcomes. Population-based screening tools with high diagnostic accuracy for the staging of fibrosis are lacking.

METHODS

Three independent cohorts, 2 with both liver biopsy and liver stiffness measurements (LSMs, n = 254 and 65) and a population sample (n = 713), were studied. The performance of a recently developed noninvasive algorithm (ADAPT [age, diabetes, PRO-C3 and platelets panel]) as well as aspartate aminotransferase-to-platelet ratio index, fibrosis-4, nonalcoholic fatty liver disease fibrosis score, and LSM was used to stage patients for significant (≥F2) and advanced (≥F3) fibrosis.

RESULTS

In the hospital-based cohorts, the N-terminal propeptide of type 3 collagen (Pro-C3) increased with fibrosis stage (P < 0.0001) and independently associated with advanced fibrosis (odds ratio = 1.091, 95% confidence interval [CI]: 1.053-1.113, P = 0.0001). ADAPT showed areas under the receiver operating characteristics curve of 0.831 (95% CI: 0.779-0.875) in the derivation and 0.879 (95% CI: 0.774-0.946) in the validation cohort for advanced fibrosis. This was superior to the existing fibrosis scores, aspartate aminotransferase-to-platelet ratio index, fibrosis-4, BARD (BMI, aspartate aminotransferase to alanine aminotransferase ratio [AAR], diabetes), and nonalcoholic fatty liver disease fibrosis score in most comparisons and comparable with LSM. Serial use of ADAPT and LSM had diagnostic accuracy of 92.5%, with 98% and 100% negative predictive value in the derivation and validation cohorts, respectively. In the population cohort, PRO-C3 associated with advanced fibrosis (P = 0.04), while ADAPT had a negative predictive value of 98% for excluding advanced fibrosis.

DISCUSSION

PRO-C3 and ADAPT reliably exclude advanced fibrosis in low-risk populations. The serial combination of ADAPT with LSM has high diagnostic accuracy with a low requirement for liver biopsy. The proposed algorithm would help stratify those who need biopsies and narrow down those patients who would need to be referred to specialty clinics.

Nomogram for predicting advanced liver fibrosis and cirrhosis in patients with chronic liver disease

BACKGROUND

We aimed to formulate a novel predictive nomogram to discriminate liver fibrosis stage in patients with chronic liver disease.

METHODS

Nomograms were established based on the results of multivariate analysis. The predictive accuracy of the nomograms was assessed by ROC analysis and calibration. Decision curve analysis (DCA) was used to determine the clinical benefit of the nomograms.

RESULTS

INR, platelets, and N-terminal propeptide type III collagen (PIIINP) were independent predictors for advanced liver fibrosis (≥ S3) and cirrhosis (S4) in patients with chronic liver disease in the training cohort. In the training set, the areas under the ROCs (AUROCs) of nomogram S3S4, APRI, FIB-4, and GPR for stage ≥ S3 were 0.83, 0.71, 0.68, and 0.74, respectively; the AUROCs of nomogram S4, APRI, FIB-4, and GPR for stage S4 were 0.88, 0.74, 0.78, and 0.79, respectively. The calibrations showed optimal agreement between the prediction by the established nomograms and actual observation. In the validation set, the AUROCs of nomogram S3S4, APRI, FIB-4, and GPR for stage ≥ S3 were 0.86, 0.79, 0.78, and 0.81, respectively; the AUROCs of nomogram S4, APRI, FIB-4, and GPR for stage S4 were 0.88, 0.77, 0.81, and 0.83, respectively. Furthermore, the decision curve analysis suggested that the nomograms represent better clinical benefits in both independent cohorts than APRI, FIB-4, and GPR.

CONCLUSION

The constructed nomograms could be a superior tool for discriminating advanced fibrosis and cirrhosis in chronic liver disease.

NAFLD-Associated HCC: Progress and Opportunities

Due to an increase in the obesity-associated metabolic syndrome of epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a leading cause of hepatocellular carcinoma (HCC) in western countries. This presents added challenges, as NAFLD-associated HCC tends to present at an advanced stage in older patients with co-morbidities. Their prognosis is generally poor with the benefits of standard therapies less certain. The pathogenesis of NAFLD-associated HCC is multifactorial and not well understood, although the risk of HCC developing undoubtedly increases as NAFLD progresses to steatohepatitis and cirrhosis. Recent advances in our understanding of the drivers of NAFLD and HCC will hopefully lead to the development of clinically relevant biomarkers, tools and strategies to aid the identification of high-risk patients, inform preventive measures, and introduction of better tolerated targeted therapies. Lifestyle modification and chemoprevention with drugs such as anti-platelets, statins and anti-diabetics are being evaluated for HCC prevention. The landmark IMBrave150 study introducing the combination of atezolizumab and bevacizumab has recently transformed the landscape of systemic therapies in HCC, with follow-up analyses and real-world data for patients with NAFLD-associated HCC eagerly anticipated. While responses may vary in ways not yet appreciated, the rate of discovery and progress suggests imminent change and opportunities.

The Role of Diagnostic Biomarkers, Omics Strategies, and Single-Cell Sequencing for Nonalcoholic Fatty Liver Disease in Severely Obese Patients

Liver disease due to metabolic dysfunction constitute a worldwide growing health issue. Severe obesity is a particularly strong risk factor for non-alcoholic fatty liver disease, which affects up to 93% of these patients. Current diagnostic markers focus on the detection of advanced fibrosis as the major predictor of liver-related morbidity and mortality. The most accurate diagnostic tools use elastography to measure liver stiffness, with diagnostic accuracies similar in normal-weight and severely obese patients. The effectiveness of elastography tools are however hampered by limitations to equipment and measurement quality in patients with very large abdominal circumference and subcutaneous fat. Blood-based biomarkers are therefore attractive, but those available to date have only moderate diagnostic accuracy. Ongoing technological advances in omics technologies such as genomics, transcriptomics, and proteomics hold great promise for discovery of biomarkers and increased pathophysiological understanding of non-alcoholic liver disease and steatohepatitis. Very recent developments have allowed for single-cell sequencing and cell-type resolution of gene expression and function. In the near future, we will therefore likely see a multitude of breakthrough biomarkers, developed from a deepened understanding of the biological function of individual cell types in the healthy and injured liver.

FIB-4 First in the Diagnostic Algorithm of Metabolic-Dysfunction-Associated Fatty Liver Disease in the Era of the Global Metabodemic

The prevalence of obesity or metabolic syndrome is increasing worldwide (globally metabodemic). Approximately 25% of the adult general population is suffering from nonalcoholic fatty liver disease (NAFLD), which has become a serious health problem. In 2020, global experts suggested that the nomenclature of NAFLD should be updated to metabolic-dysfunction-associated fatty liver disease (MAFLD). Hepatic fibrosis is the most significant determinant of all cause- and liver -related mortality in MAFLD. The non-invasive test (NIT) is urgently required to evaluate hepatic fibrosis in MAFLD. The fibrosis-4 (FIB-4) index is the first triaging tool for excluding advanced fibrosis because of its accuracy, simplicity, and cheapness, especially for general physicians or endocrinologists, although the FIB-4 index has several drawbacks. Accumulating evidence has suggested that vibration-controlled transient elastography (VCTE) and the enhanced liver fibrosis (ELF) test may become useful as the second step after triaging by the FIB-4 index. The leading cause of mortality in MAFLD is cardiovascular disease (CVD), extrahepatic malignancy, and liver-related diseases. MAFLD often complicates chronic kidney disease (CKD), resulting in increased simultaneous liver kidney transplantation. The FIB-4 index could be a predictor of not only liver-related mortality and incident hepatocellular carcinoma, but also prevalent and incident CKD, CVD, and extrahepatic malignancy. Although NITs as milestones for evaluating treatment efficacy have never been established, the FIB-4 index is expected to reflect histological hepatic fibrosis after treatment in several longitudinal studies. We here review the role of the FIB-4 index in the management of MAFLD.

Noninvasive Evaluation for Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis

PURPOSE

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and has the potential risk for progressing to nonalcoholic steatohepatitis (NASH), which is associated with a greater risk for complications of chronic liver disease. Noninvasive testing has been evaluated for diagnosis, risk stratification, disease progression, and assessing response to therapy. The purpose of this narrative review was to outline the current noninvasive testing modalities for the diagnostic evaluation of NAFLD and NASH, while discussing possible markers that could be used for monitoring response to therapies.

METHODS

The PubMed and Cochrane databases were searched for relevant articles that evaluated the diagnosis of NAFLD/NASH with serum biomarkers and/or imaging.

FINDINGS

Serum biomarkers, imaging modalities, and combinations/serial algorithms involved in the diagnosis of NAFLD and NASH are outlined. In addition, noninvasive modalities that have been used for assessing response to therapies in clinical trials are discussed.

IMPLICATIONS

Liver biopsy currently remains the gold standard for diagnosis and is often used in clinical trials to assess treatment response. However, developing safe and accessible noninvasive modalities for diagnosis and monitoring will have greater impact and relevance, as biopsy may not always be feasible in all clinical settings.

The Relevance of Noninvasive Tools To Assess Fibrosis in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver diseases worldwide, involving about 25% of people. NAFLD incorporates a large spectrum of pathological conditions, from simple steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis and its complications include hepatic decompensation and hepatocellular carcinoma (HCC). This progression occurs, over many years, in an asymptomatic way, until advanced fibrosis appears. Thus, the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis are key issues. To date, the histological assessment of fibrosis with liver biopsy is the gold standard, but obviously, invasiveness is the greater threshold. In addition, rare but potentially life-threatening complications, poor acceptability, sampling variability and cost maybe restrict its use. Furthermore, due to the epidemic of NAFLD worldwide and several limitations of liver biopsy evaluation, noninvasive assessment tools to detect fibrosis in NAFLD patients are needed.

Management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is a very common medical condition, driven by a combination of genetic and lifestyle factors, ultimately producing a severe chronic liver disease and increased cardiovascular risk. Most people are asymptomatic for a long time, and their daily life is unaffected, leading to difficulty in identifying and managing people who slowly progress to non-alcoholic steatohepatitis (NASH), NASH-cirrhosis, and eventually hepatocellular carcinoma. Despite advances in the understanding of pathogenic mechanisms and the identification of liver fibrosis as the strongest factor in predicting disease progression, no specific treatments have been approved by regulatory agencies. Outside controlled trials, treatment is generally limited to lifestyle intervention aimed at weight loss. Pioglitazone remains the drug of choice to reduce progression of fibrosis in people with diabetes, although it is often used off-label in the absence of diabetes. Vitamin E is mainly used in children and may be considered in adults without diabetes. Several drugs are under investigation according to the agreed targets of reduced NASH activity without worsening of fibrosis or improving fibrosis without worsening of NASH. Anti-inflammatory, anti-fibrotic agents and metabolism modulators have been tested in either phase III or phase IIb randomized controlled trials; a few failed, and others have produced marginally positive results, but only a few are being tested in extension studies. The development of non-invasive, easily repeatable surrogate biomarkers and/or imaging tools is crucial to facilitate clinical studies and limit liver biopsy.

Nuclear hormone and peptide hormone therapeutics for NAFLD and NASH

Background

Non-alcoholic steatohepatitis (NASH) is a spectrum of histological liver pathologies ranging from hepatocyte fat accumulation, hepatocellular ballooning, lobular inflammation, and pericellular fibrosis. Based on early investigations, it was discovered that visceral fat accumulation, hepatic insulin resistance, and atherogenic dyslipidemia are pathological triggers for NASH progression. As these pathogenic features are common with obesity, type 2 diabetes (T2D), and atherosclerosis, therapies that target dysregulated core metabolic pathways may hold promise for treating NASH, particularly as first-line treatments.

Scope of Review

In this review, the latest clinical data on nuclear hormone- and peptide hormone-based drug candidates for NASH are reviewed and contextualized, culminating with a discovery research perspective on emerging combinatorial therapeutic approaches that merge nuclear and peptide strategies.

Major Conclusion

Several drug candidates targeting the metabolic complications of NASH have shown promise in early clinical trials, albeit with unique benefits and challenges, but questions remain regarding their translation to larger and longer clinical trials, as well as their utility in a more diseased patient population. Promising polypharmacological approaches can potentially overcome some of these perceived challenges, as has been suggested in preclinical models, but deeper characterizations are required to fully evaluate these opportunities.

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Despite no approved treatments for NASH, several drug candidates have shown promise in early clinical trials.

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Therapies targeting metabolic pathologies of NASH have shown efficacy to reduce hepatic fat content and improve fibrosis.

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Many of these therapies have been rationally designed to mimic nuclear hormone or peptide hormone action.

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Despite provocative preclinical findings of nuclear and peptide hormone combination, clinical translation remains unproven.

Endotrophin, a pro-peptide of Type VI collagen, is a biomarker of survival in cirrhotic patients with hepatocellular carcinoma

AIM

Type VI collagen, is emerging as a signaling collagen originating from different types of fibroblasts. A specific fragment of Type VI collagen, the pro-peptide, is also known as the hormone endotrophin. We hypothesized that this fibroblast hormone would be of particular relevance in cancer types with a high amount of fibrosis activity, namely for outcome in hepatocellular carcinoma (HCC) cirrhotic patients.

PATIENTS & METHODS

Plasma C6M, PRO-C6 and alphafeto-protein (AFP) were assessed in 309 patients with mixed etiologies (hepatitis C, hepatitis B, alcohol and nonalcoholic fatty liver) diagnosed as cirrhotics, cirrhotics with HCC, noncirrhotics and healthy controls. Progression-free survival and overall survival (OS) data were collected up to 6120 days after diagnosis. The ability of each marker to predict survival was investigated.

RESULTS & CONCLUSION

The level of endotrophin assessed by PRO-C6 was able to separate healthy controls, noncirrhotics and cirrhotics from HCC (p < 0.05-0.0001). Both endotrophin and C6M provided value in the prediction of OS in cirrhotic patients with HCC. In the multivariate analysis for identifying HCC, in patients with high endotrophin (highest quartile) and that were positive for AFP (≥20 IU/ml), the hazard ratio for predicting OS was increased from 3.7 (p = 0.0006) to 14.4 (p = 0.0001) when comparing with AFP positive as a stand-alone marker. In conclusion, plasma levels for markers of Type VI collagen remodeling were associated with survival in cirrhotic patients with HCC. A combination of AFP with endotrophin improved the prognostic value compared with AFP alone for predicting OS in cirrhotic patients with HCC.

Macrophage Markers Do Not Add to the Prediction of Liver Fibrosis by Transient Elastography in Patients With Metabolic Associated Fatty Liver Disease

Background and Aims: Non-invasive fibrosis staging is essential in metabolic associated fatty liver disease (MAFLD). Transient elastography (TE) is a well-established method for liver fibrosis assessment. We have previously shown that the macrophage marker sCD163 is an independent predictor for fibrosis in MAFLD. In the present study we tested whether the combination of macrophage markers and TE improves fibrosis prediction. Methods: We measured macrophage markers soluble (s)CD163 and mannose receptor (sMR) in two independent cohorts from Italy (n = 141) and Sweden (n = 70) with biopsy-proven MAFLD and available TE. Results: In the Italian cohort, TE and sCD163 showed similar moderate associations with liver fibrosis (rho = 0.56, p < 0.001 and rho = 0.42, p < 0.001, respectively). TE had an area under the Receiver Operating Characteristics curve (AUROC, with 95% CI) for fibrosis; F ≥ 2 = 0.79 (0.72-0.86), F ≥ 3 = 0.81 (0.73-0.89), F4 = 0.95 (0.90-1.0). sCD163 also predicted fibrosis well [F ≥ 2 = 0.71 (0.63-0.80), F ≥ 3 = 0.82 (0.74-0.90), F4 = 0.89 (0.76-1.0)]. However, combining sCD163 and TE did not improve the AUROCs significantly [F ≥ 2 = 0.79 (0.72-0.86), F ≥ 3 = 0.85 (0.78-0.92), F4 = 0.97 (0.93-1.0)]. In the Swedish cohort, TE showed a closer association with fibrosis (rho = 0.73, p < 0.001) than sCD163 (rho = 0.43, p < 0.001) and sMR (rho = 0.46, p < 0.001). TE predicted fibrosis well [F ≥ 2 = 0.88 (0.80-0.97), F ≥ 3 = 0.90 (0.83-0.97), F4 = 0.87 (0.78-0.96)], whereas sCD163 did not (best AUROC 0.75). sMR showed a better prediction [F ≥ 2 = 0.68 (0.56-0.81), F ≥ 3 = 0.82 (0.71-0.92), F4 = 0.79 (0.66-0.93)], but the addition of sMR did not further improve the prediction of fibrosis by TE. Conclusion: In these cohorts of MAFLD patients, TE was superior to macrophage markers for fibrosis prediction and in contrast to our hypothesis the addition of these markers to TE did not improve its predictive capability.

Nonalcoholic Fatty Liver Disease (NAFLD) for Primary Care Providers: Beyond the Liver

Abstract::

Nonalcoholic fatty liver disease (NAFLD) has consolidated as a major public health problem, affecting ~25% of the global population. This percentage is significantly higher in the setting of obesity and/or type 2 diabetes. Presence of NAFLD is associated with severe liver complications, such as nonalcoholic steatohepatitis (NASH; i.e., presence of inflammation and necrosis), cirrhosis and hepatocellular carcinoma. However, the majority of these patients die of cardiovascular disease. For this reason, management of this condition requires a multidisciplinary team, where primary care providers are at center stage. However, important misconceptions remain among primary care providers, preventing them from appropriately approach these patients. Nonalcoholic fatty liver disease should be understood as part of a systemic disease, characterized for abnormal accumulation of fat in tissues other than the adipose tissue. This, in turn, produces dysfunction of those organs or tissues (process sometimes referred to as lipotoxicity). Therefore, due to the systemic nature of this condition, it should not surprise that NAFLD is closely related to other metabolic conditions. In this review, we will focus on the extrahepatic manifestations of NAFLD and its metabolic and cardiovascular implications. We believe these are the most important issues primary care providers should understand, in order to effectively manage these complicated patients. In addition, we have provided a simple and straightforward approach to the diagnosis and treatment of patients with NAFLD and/or NASH. We hope this review will serve as a guide for primary care providers to approach their patients with NAFLD.

[Liver-specific diagnostic for non-alcoholic fatty liver disease (NAFLD) - time to replace liver biopsy?]

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. In Germany, the prevalence in the adult population is estimated at 24 % and the incidence is increasing. Prognostically, the distinction between early and advanced stages of the disease is important. In particular, the extent of scarring considered as liver fibrosis is of prognostic significance. Patients with advanced fibrosis and cirrhosis show increased mortality. Liver fibrosis develops as a consequence of a persistent inflammation of the liver tissue over time. Since inflammation and fibrosis are histological features, liver biopsy is considered the reference method in the diagnosis of NAFLD. More recently, non-invasive diagnostic methods for staging (of fibrosis) and grading (activity) of the disease are being developed and validated. The current review summarizes new developments in non-invasive liver diagnostics.

The Asian Pacific Association for the Study of the Liver clinical practice guidelines for the diagnosis and management of metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) is the principal worldwide cause of liver disease and affects nearly a quarter of the global population. The objective of this work was to present the clinical practice guidelines of the Asian Pacific Association for the Study of the Liver (APASL) on MAFLD. The guidelines cover various aspects of MAFLD including its epidemiology, diagnosis, screening, assessment, and treatment. The document is intended for practical use and for setting the stage for advancing clinical practice, knowledge, and research of MAFLD in adults, with specific reference to special groups as necessary. The guidelines also seek to improve patient care and awareness of the disease and assist stakeholders in the decision-making process by providing evidence-based data. The guidelines take into consideration the burden of clinical management for the healthcare sector.

Cross-Linked Multimeric Pro-Peptides of Type III Collagen (PC3X) in Hepatocellular Carcinoma - A Biomarker That Provides Additional Prognostic Value in AFP Positive Patients

Purpose

Non-invasive biomarkers for diagnosing and prognosing hepatocellular carcinoma (HCC) are urgently needed. Cirrhosis is present in 80–90% of HCC patients. Cirrhosis is characterized by deposition and cross-linking of collagens that have crucial roles in HCC initiation and progression. We evaluated circulating cross-linked pro-peptides of type III collagen (PC3X) as a diagnostic and prognostic biomarker for HCC.

Patients and Methods

PC3X was measured by ELISA in plasma from patients with HCC (n=79), cirrhosis (n=86), non-cirrhotic hepatitis-B infection (n=74) and from healthy controls (n=44). PC3X was compared to the liver fibrosis marker PRO-C3 and the HCC tumor-cell derived marker alpha-fetoprotein (AFP). Diagnostic and prognostic potential was evaluated by AUROC and by calculating hazard ratios (HR) for progression-free survival (PFS) and overall survival (OS).

Results

PC3X, PRO-C3 and AFP were significantly elevated in patients with HCC compared to other liver diseases and healthy controls (p=0.0002, p<0.0001). In patients with normal AFP (<20 IU/mL), PC3X and PRO-C3 separated HCC from cirrhosis with an AUROC of 0.72 and 0.68, respectively. High PC3X and AFP predicted for poor PFS (HR_PC3X=1.80, p=0.032; HR_AFP=1.70, p=0.031) and OS (HR_PC3X=2.12, p=0.024; HR_AFP=2.55; p=0.003), whereas PRO-C3 did not (PFS: HR=1.19, p=0.059 and OS: HR=1.12, p=0.324). PC3X was independent of AFP (PFS: HR=1.74, p=0.045 and OS: HR=2.21, p=0.018) and combining the two improved prognostic value (PFS: HR=2.66, p=0.004 and OS: HR=5.86, p<0.0001).

Conclusion

PC3X is associated with HCC independent of AFP and provides diagnostic and prognostic value for HCC patients. If validated, this suggests that PC3X has biomarker potential for HCC.

Noninvasive Tests in the Assessment of NASH and NAFLD Fibrosis: Now and Into the Future

Noninvasive serum and imaging methods offer accessible, accurate, and safe assessment of fibrosis severity in nonalcoholic fatty liver disease. In contrast, current serum and imaging methods for the prediction of nonalcoholic steatohepatitis are not sufficiently accurate for routine clinical use. Serum fibrosis markers that incorporate direct measures of fibrogenesis (for example, hyaluronic acid) or fibrinolysis are generally more accurate than biomarkers not incorporating direct measures of fibrogenesis. Elastography methods are more accurate than serum markers for fibrosis assessment and particularly for the determination of cirrhosis, but have a significant failure and/or unreliability rate in obese individuals. To overcome this, combining serum and elastography methods in a sequential manner minimizes indeterminate results and maintains accuracy. The accuracy of current noninvasive methods for monitoring fibrosis response to treatment are limited; however, new tools derived from "omic" methodologies offer promise for the future.

The role of noninvasive biomarkers in diagnosis and risk stratification in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronically elevated liver enzymes. Diagnosis and risk stratification of NAFLD remains clinically challenge as patients with NAFLD are either asymptomatic or have nonspecific presenting complaints and may have normal liver enzymes. Nonalcoholic steatohepatitis (NASH), the clinically aggressive variant of NAFLD, is also difficult to differentiate noninvasively, and a liver biopsy is required to definitively diagnose NASH. Thus, the definitive diagnosis and risk stratification of NAFLD is embedded in histological assessment of the liver. Several clinical aides been investigated in an attempt to risk stratify and identify patients noninvasively as doing a liver biopsy in all patients with NAFLD are not feasible. Since these biomarkers are unable to differentiate NASH from non-NASH, they have leveraged biochemical changes within the liver as patients progress to varying degree of hepatic fibrosis to identify patients with moderate fibrosis (fibrosis stage 2 or greater) and advanced fibrosis (fibrosis stage 3 or greater) to help guide the need for additional and more definitive workup. These clinical aides span from by-products of apoptosis to statistical modelling of clinically available data to identify 'at-risk' patients with NAFLD. The current review will focus the diagnostic performance of these noninvasive serum-based biomarkers in NAFLD.

The role of omics in the pathophysiology, diagnosis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifaceted metabolic disorder, whose spectrum covers clinical, histological and pathophysiological developments ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) and liver fibrosis, potentially evolving into cirrhosis, hepatocellular carcinoma and liver failure. Liver biopsy remains the gold standard for diagnosing NAFLD, while there are no specific treatments. An ever-increasing number of high-throughput Omics investigations on the molecular pathobiology of NAFLD at the cellular, tissue and system levels produce comprehensive biochemical patient snapshots. In the clinical setting, these applications are considerably enhancing our efforts towards obtaining a holistic insight on NAFLD pathophysiology. Omics are also generating non-invasive diagnostic modalities for the distinct stages of NAFLD, that remain though to be validated in multiple, large, heterogenous and independent cohorts, both cross-sectionally as well as prospectively. Finally, they aid in developing novel therapies. By tracing the flow of information from genomics to epigenomics, transcriptomics, proteomics, metabolomics, lipidomics and glycomics, the chief contributions of these techniques in understanding, diagnosing and treating NAFLD are summarized herein.

The diagnostic conundrum in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver alteration worldwide. It encompasses a spectrum of disorders that range from simple steatosis to a progressive form, defined non-alcoholic steatohepatitis (NASH), that can lead to advanced fibrosis and eventually cirrhosis and hepatocellular carcinoma. On liver histology, NASH is characterized by the concomitant presence of significant fat accumulation and inflammatory reaction with hepatocellular injury. Until now, liver biopsy is still required to differentiate simple steatosis from NASH and evaluate the degree of liver fibrosis. Unfortunately, this technique has well-known limitations, including invasiveness and expensiveness. Moreover, it may be biased by sampling error and intra- or inter-observed variability. Furthermore, due to the increasing prevalence of NAFLD worldwide, to program a systematic screening with liver biopsy is not imaginable. In recent years, different techniques were developed and validated with the aim of non-invasively identifying NASH and assess liver fibrosis degrees. The non-invasive tests range from simple blood-tests analyses to composite scores and complex imaging techniques. Nevertheless, even if they could represent cost-effective strategies for diagnosing NASH, advanced fibrosis and cirrhosis, their accuracy and consequent usefulness are to be discussed. With this aim, in this review the authors summarize the current state of non-invasive assessment of NAFLD. In particular, in addition to the well-established tests, the authors describe the future perspectives in this field, reporting the latest tests based on OMICS, gut-miocrobioma and micro-RNAs. Finally, the authors provide an accurate assessment of how these non-invasive tools perform in clinical practice depending on the clinical context, with the aim of giving the clinicians a useful tool to try to resolve the diagnostic conundrum of NAFLD.

A composite biomarker using multiparametric magnetic resonance imaging and blood analytes accurately identifies patients with non-alcoholic steatohepatitis and significant fibrosis

Non-alcoholic steatohepatitis (NASH) is major health burden lacking effective pharmacological therapies. Clinical trials enrol patients with histologically-defined NAFLD (non-alcoholic fatty liver disease) activity score (NAS) ≥ 4 and Kleiner-Brunt fibrosis stage (F) ≥ 2; however, screen failure rates are often high following biopsy. This study evaluated a non-invasive MRI biomarker, iron-corrected T1 mapping (cT1), as a diagnostic pre-screening biomarker for NASH. In a retrospective analysis of 86 biopsy confirmed NAFLD patients we explored the potential of blood and imaging biomarkers, both in isolation and in combination, to discriminate those who have NAS ≥ 4 and F ≥ 2 from those without. Stepwise logistic regression was performed to select the optimal combination of biomarkers, diagnostic accuracy was determined using area under the receiver operator curve and model validated confirmed with and fivefold cross-validation. Results showed that levels of cT1, AST, GGT and fasting glucose were all good predictors of NAS ≥ 4 and F ≥ 2, and the model identified the combination of cT1-AST-fasting glucose (cTAG) as far superior to any individual biomarker (AUC 0.90 [0.84–0.97]). This highlights the potential utility of the composite cTAG score for screening patients prior to biopsy to identify those suitable for NASH clinical trial enrolment.

Noninvasive Tests (NITs) for Hepatic Fibrosis in Fatty Liver Syndrome

Fatty liver syndrome is an emerging health problem in the world, due to the high prevalence of obesity and alcohol use disorder. Given the nature of the disease's advancement to cirrhosis and liver-related complications, it is important to assess the severity of the disease, which is typically done via a liver biopsy. Due to the limitations and risks of liver biopsy, the role of noninvasive tests is essential and evolving to stratify the stage of the liver disease, predict the outcomes, and/or monitor the treatment response. This review is focused on noninvasive tests, including the use of serum-based biomarkers, ultrasound-based shear wave elastography, transient elastography, and magnetic resonance elastography in both clinical and research settings.

Comprehensive assessment of ECM turnover using serum biomarkers establishes PBC as a high-turnover autoimmune liver disease

Background & Aims

Primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) are phenotypically distinct autoimmune liver diseases that progress to cirrhosis and liver failure; however, their histological fibrosis distribution differs. We investigated the extracellular matrix (ECM) profiles of patients with PSC, PBC, and AIH to establish whether the diseases display differential patterns of ECM turnover.

Methods

Serum samples were retrospectively collected from the UK (test cohort; PSC n = 78; PBC n = 74; AIH n = 58) and Norway (validation cohort; PSC n = 138; PBC n = 28; AIH n = 27). Patients with ulcerative colitis without liver disease (n = 194) served as controls. We assessed specific serological biomarkers of ECM turnover: type III and V collagen formation (PRO-C3, PRO-C5), degradation of type III and IV collagen (C3M, C4M), biglycan (BGM) and citrullinated vimentin (VICM).

Results

Most of the ECM markers showed elevated serum levels in PBC compared with PSC or AIH (p <0.01). PRO-C3 correlated well with liver stiffness and showed the most striking differences between advanced and non-advanced liver disease; several of the other ECM markers were also associated with stage. PRO-C3 and other ECM markers were inversely associated with ursodeoxycholic acid treatment response in PBC and remission in AIH. All ECM remodelling markers were significantly elevated (p <0.05) in patients with PSC, PBC, or AIH compared with ulcerative colitis.

Conclusions

In this first study comparing ECM turnover in autoimmune liver diseases, we found increased ECM turnover in PBC compared with either PSC or AIH. The study indicates that ECM remodelling is different in PSC, PBC, and AIH, suggesting differing opportunities for therapeutic intervention.

Lay summary

The level of scarring is linked to prognosis in autoimmune liver diseases such as primary sclerosing cholangitis, primary biliary cholangitis, and autoimmune hepatitis; hence, the scarring process is a possible target for novel therapy. Investigating the scarring process using highly specific technology, we show that the scarring process is different between the 3 autoimmune liver diseases, and this may have important implications for the development of medical treatment.

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Serological biomarkers specifically targeting extracellular matrix remodelling enable evaluation of the dynamics of fibrosis evolution.

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ECM turnover was increased in PBC compared with PSC and AIH.

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ECM markers, particularly PRO-C3, were associated with disease stage in the autoimmune liver diseases and with clinical outcome in PSC.

Cenicriviroc Treatment for Adults With Nonalcoholic Steatohepatitis and Fibrosis: Final Analysis of the Phase 2b CENTAUR Study

BACKGROUND AND AIMS

Cenicriviroc (CVC) is a C-C chemokine receptors type 2 and 5 dual antagonist under evaluation for treating liver fibrosis in adults with nonalcoholic steatohepatitis (NASH). Year 1 primary analysis of the 2-year CENTAUR study showed that CVC had an antifibrotic effect without impacting steatohepatitis. Herein, we report the final data from year 2 exploratory analyses.

APPROACH AND RESULTS

This was a randomized, controlled study of adults with NASH, nonalcoholic fatty liver disease activity score ≥4, and NASH Clinical Research Network stage 1-3 fibrosis. Participants in arms A and C received CVC 150 mg or placebo, respectively, for 2 years; arm B received placebo in year 1 and switched to CVC in year 2. Liver biopsy was performed at baseline, year 1, and year 2. Of 289 randomized participants, 242 entered year 2. At year 2, 24% of patients who switched to CVC and 17% who remained on placebo achieved ≥1-stage fibrosis improvement and no worsening of NASH (P = 0.37). Twice the proportion on CVC who achieved fibrosis response at year 1 maintained benefit at year 2 (60% arm A versus 30% arm C), including 86% on CVC who had stage 3 fibrosis at baseline. Over 2 years, a similar proportion on CVC or placebo achieved ≥1-stage fibrosis improvement and no worsening of NASH (15% arm A versus 17% arm C). In patients with fibrosis responses, we observed consistent reductions in levels of N-terminal type 3 collagen propeptide and enhanced liver fibrosis scores, while increases in aspartate aminotransferase-to-platelet ratio index and Fibrosis-4 scores were consistently observed in nonresponders. Safety profile was comparable across groups.

CONCLUSIONS

CVC was well tolerated, and year 2 data corroborate antifibrotic findings from year 1. The majority on CVC who achieved fibrosis response at year 1 maintained it at year 2, with greater effect in advanced fibrosis. ClinicalTrials.gov number, NCT02217475 (CENTAUR).

Identifying High-Risk NASH Patients: What We Know so Far

Steatosis is a condition of hepatic fat overload that is associated with overweight and the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease with a global impact on healthcare. A proportion of NAFLD patients develops nonalcoholic steatohepatitis (NASH), liver fibrosis, cirrhosis or hepatocellular carcinoma (HCC). Identifying patients at risk for potentially life-threatening complications is crucial in their prevention, surveillance and treatment. In addition to hepatic disease progression (cirrhosis, portal hypertension, HCC), NAFLD patients are also at risk of cardiovascular and metabolic diseases as well as extrahepatic malignancies. Liver fibrosis is related to morbidity and mortality in NASH patients, and biomarkers, imaging techniques (ultrasound, elastography, MRI) as well as liver biopsy help in diagnosing fibrosis. In this review, we discuss the tools for identifying patients at risk and their reasonable application in clinical routine in order to stratify prevention and treatment of this emerging disease.

Evaluating the Therapeutic Potential of Cenicriviroc in the Treatment of Nonalcoholic Steatohepatitis with Fibrosis: A Brief Report on Emerging Data

Non-alcoholic steatohepatitis (NASH) is associated with significant morbidity and mortality due to liver cirrhosis, liver failure, and hepatocellular carcinoma, and represents a leading indication for liver transplantation in the United States (U.S.). A growing spectrum of novel therapies are currently in clinical development and target several mechanisms of action which address hepatic steatosis, steatohepatitis, and hepatic fibrosis. Cenicriviroc (Allergan, Dublin, Ireland) is a novel oral antagonist of CC-motif chemokine receptors 2 and 5 (CCR2/5) which have demonstrated expression on circulating monocytes and Kupffer cells. Preclinical models have confirmed that CCR2/5 antagonism may block fat accumulation and Kupffer cell activation and disrupt monocyte/macrophage recruitment and hepatic stellate cell activation responsible for fibrogenesis. Herein we review results from the phase 2b CENTAUR trial and study designs for the phase 2b TANDEM and phase 3 AURORA trials and discuss the potential role of cenicriviroc in future pharmacotherapy for NASH fibrosis.

The liver matrisome - looking beyond collagens

The extracellular matrix (ECM) is a diverse microenvironment that maintains bidirectional communication with surrounding cells to regulate cell and tissue homeostasis. The classical definition of the ECM has more recently been extended to include non-fibrillar proteins that either interact or are structurally affiliated with the ECM, termed the 'matrisome.' In addition to providing the structure and architectural support for cells and tissue, the matrisome serves as a reservoir for growth factors and cytokines, as well as a signaling hub via which cells can communicate with their environment and vice-versa. The matrisome is a master regulator of tissue homeostasis and organ function, which can dynamically and appropriately respond to any stress or injury. Failure to properly regulate these responses can lead to changes in the matrisome that are maladaptive. Hepatic fibrosis is a canonical example of ECM dyshomeostasis, leading to accumulation of predominantly collagenous ECM; indeed, hepatic fibrosis is considered almost synonymous with collagen accumulation. However, the qualitative and quantitative alterations of the hepatic matrisome during fibrosis are much more diverse than simple accumulation of collagens and occur long before fibrosis is histologically detected. A deeper understanding of the hepatic matrisome and its response to injury could yield new mechanistic insights into disease progression and regression, as well as potentially identify new biomarkers for both. In this review, we discuss the role of the ECM in liver diseases and look at new "omic" approaches to study this compartment.

Advances in non-invasive assessment of hepatic fibrosis

Liver fibrosis should be assessed in all individuals with chronic liver disease as it predicts the risk of future liver-related morbidity and thus need for treatment, monitoring and surveillance. Non-invasive fibrosis tests (NITs) overcome many limitations of liver biopsy and are now routinely incorporated into specialist clinical practice. Simple serum-based tests (eg, Fibrosis Score 4, non-alcoholic fatty liver disease Fibrosis Score) consist of readily available biochemical surrogates and clinical risk factors for liver fibrosis (eg, age and sex). These have been extensively validated across a spectrum of chronic liver diseases, however, tend to be less accurate than more 'complex' serum tests, which incorporate direct measures of fibrogenesis or fibrolysis (eg, hyaluronic acid, N-terminal propeptide of type three collagen). Elastography methods quantify liver stiffness as a marker of fibrosis and are more accurate than simple serum NITs, however, suffer increasing rates of unreliability with increasing obesity. MR elastography appears more accurate than sonographic elastography and is not significantly impacted by obesity but is costly with limited availability. NITs are valuable for excluding advanced fibrosis or cirrhosis, however, are not sufficiently predictive when used in isolation. Combining serum and elastography techniques increases diagnostic accuracy and can be used as screening and confirmatory tests, respectively. Unfortunately, NITs have not yet been demonstrated to accurately reflect fibrosis change in response to treatment, limiting their role in disease monitoring. However, recent studies have demonstrated lipidomic, proteomic and gut microbiome profiles as well as microRNA signatures to be promising techniques for fibrosis assessment in the future.

Review article: the signalling and functional role of the extracellular matrix in the development of liver fibrosis

BACKGROUND

Patients with liver fibrosis show a large heterogeneity, and for that reason effective treatments are still lacking. Emerging data suggest that there is more to fibrosis than previously understood. Opposed to earlier belief of being a passive scaffold for cells to reside in, the extracellular matrix (ECM) is now known to hold both signalling and functional properties important for the development of fibrosis. The interaction between the ECM and the collagen-producing cells determines the course of the disease but is still poorly understood. Exploring the dynamics of this interplay will aid in the development of effective treatments.

AIM

To summarise and discuss the latest advances in the pathogenesis of liver fibrosis as well as key mediators of early disease progression.

METHODS

Through literature search using databases including PubMed and Google Scholar, manuscripts published between 1961 and 2019 were included to assess both well-established and recent theories of fibrosis development. Both pre-clinical and clinical studies were included.

RESULTS

Fibrosis alters the structure of the ECM releasing signalling fragments with the potential to escalate disease severity. In a diseased liver, hepatic stellate cells and other fibroblasts, together with hepatocytes and sinusoidal cells, produce an excessive amount of collagens. The cell-to-collagen interactions are unique in the different liver aetiologies, generating ECM profiles with considerable patient-monitoring potential.

CONCLUSIONS

The local milieu in the injured area affects the course of fibrosis development in a site-specific manner. Future research should focus on the dissimilarities in the ECM profile between different aetiologies of liver fibrosis.

Applying Non-Invasive Fibrosis Measurements in NAFLD/NASH: Progress to Date

Nonalcoholic fatty liver disease (NAFLD) has now become a worldwide health issue due to the obesity epidemic, affecting approximately 90% of the obese population and 15-40% of the general population. It is the most common form of chronic liver disease in the United States. NAFLD constitutes a spectrum of diseases ranging in severity from mild, such as fatty liver, progressing into nonalcoholic steatohepatitis (NASH), then fibrosis, and ending with cirrhosis. NASH and increasing fibrosis stage are associated with increased morbidity and mortality; the fibrosis stage is therefore a critical element of risk stratification needed to determine therapeutic approach and also the response to treatment. Liver biopsy is considered the 'gold standard' in the diagnosis of NAFLD. However, it is not practical for widespread clinical use because it is invasive, costly, and associated with complications including occasional death. These limitations have driven the development of noninvasive tests that can accurately predict the fibrosis stage in those with NAFLD. In this review, we provide a concise overview of different non-invasive measurements used for NAFLD/NASH.

The Role of Insulin Resistance and Diabetes in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) consists of the entire spectrum of fatty liver disease in patients without significant alcohol consumption, ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) to cirrhosis, with NASH recently shown as an important cause of hepatocellular carcinoma (HCC). There is a close relationship between insulin resistance (IR) and NAFLD, with a five-fold higher prevalence of NAFLD in patients with type 2 diabetes (T2DM) compared to that in patients without T2DM. IR is involved in the progression of disease conditions such as steatosis and NASH, as well as hepatic fibrosis progression. The mechanisms underlying these processes involve genetic factors, hepatic fat accumulation, alterations in energy metabolism, and inflammatory signals derived from various cell types including immune cells. In NASH-associated fibrosis, the principal cell type responsible for extracellular matrix production is the hepatic stellate cell (HSC). HSC activation by IR involves “direct” and “indirect” pathways. This review will describe the molecular mechanisms of inflammation and hepatic fibrosis in IR, the relationship between T2DM and hepatic fibrosis, and the relationship between T2DM and HCC in patients with NAFLD.

Exercise Attenuates the Transition from Fatty Liver to Steatohepatitis and Reduces Tumor Formation in Mice

Non-alcoholic fatty liver disease (NAFLD) leads to steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma. For sedentary patients, lifestyle interventions combining exercise and dietary changes are a cornerstone of treatment. However, the benefit of exercise alone when dietary changes have failed is uncertain. We query whether exercise alone arrests the progression of NASH and tumorigenesis in a choline-deficient, high-fat diet (CD-HFD) murine model. Male C57Bl/6N mice received a control diet or CD-HFD for 12 weeks. CD-HFD mice were randomized further for 8 weeks of sedentariness (SED) or treadmill exercise (EXE). CD-HFD for 12 weeks produced NAFL. After 20 weeks, SED mice developed NASH and hepatic adenomas. Exercise attenuated the progression to NASH. EXE livers showed lower triglycerides and tumor necrosis factor-α expression, less fibrosis, less ballooning, and a lower NAFLD activity score than did SED livers. Plasma transaminases and triglycerides were lower. Exercise activated AMP-activated protein kinase (AMPK) with inhibition of mTORC1 and decreased S6 phosphorylation, reducing hepatocellular adenoma. Exercise activated autophagy with increased LC3-II/LC3-I and mitochondrial recruitment of phosphorylated PTEN-induced kinase. Therefore, exercise attenuates the transition from NAFL to NASH, improves biochemical and histological parameters of NAFLD, and impedes the progression of fibrosis and tumorigenesis associated with enhanced activation of AMPK signaling and favors liver autophagy. Our work supports the benefits of exercise independently of dietary changes.

Applications and Limitations of Noninvasive Methods for Evaluating Hepatic Fibrosis in Patients With Nonalcoholic Fatty Liver Disease

http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-4-reading-robinson a video presentation of this article https://www.wileyhealthlearning.com/Activity/7088585/disclaimerspopup.aspx questions and earn CME.

Exploring the role of extracellular matrix proteins to develop biomarkers of plaque vulnerability and outcome

Cardiovascular disease (CVD) is the most common cause of death in industrialized countries. One underlying cause is atherosclerosis, which is a systemic disease characterized by plaques of retained lipids, inflammatory cells, apoptotic cells, calcium and extracellular matrix (ECM) proteins in the arterial wall. The biologic composition of an atherosclerotic plaque determines whether the plaque is more or less vulnerable, that is prone to rupture or erosion. Here, the ECM and tissue repair play an important role in plaque stability, vulnerability and progression. This review will focus on ECM remodelling in atherosclerotic plaques, with focus on how ECM biomarkers might predict plaque vulnerability and outcome.

Collagen biology and non-invasive biomarkers of liver fibrosis

There is an unmet need for high-quality liquid biomarkers that can safely and reproducibly predict the stage of fibrosis and the outcomes of chronic liver disease (CLD). The requirement for such markers has intensified because of the high global prevalence of diseases such as non-alcoholic fatty liver disease (NAFLD). In particular, there is a need for diagnostic and prognostic tools, as well as predictive biomarkers that reflect the efficacy of interventions, as described by the BEST criteria (Biomarkers, EndpointS, and other Tools Resource). This review covers the various liver collagens, their functional role in tissue homeostasis and delineates the common nomenclature for biomarkers based on BEST criteria. It addresses the common confounders affecting serological biomarkers, and describes defined collagen epitope biomarkers that originate from the dynamic processes of extracellular matrix (ECM) remodelling during liver injury.

Addition of trans fat and alcohol has divergent effects on atherogenic diet-induced liver injury in rodent models of steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are common causes of chronic liver disease. The overlap between ALD and NAFLD suggests the existence of metabolic steatohepatitis. Development of in vivo models that reflect various aspects of human steatohepatitis is essential for drug discovery. We aimed to characterize several models of steatohepatitis (SH) and to investigate whether the pathology could be modulated. Sprague-Dawley rats were fed a high-fat diet (HFD) for 9 wk, followed by either a high-fat, high-cholesterol and cholate diet (HFC) or a HFC diet containing 13% trans fat (HFC-TF). A subset received 15% ethanol-water twice a week for 12 wk. Serum triglycerides, cholesterol, LDL, HDL, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and rodent NH₂-terminal propeptide of type III collagen (rPRO-C3) were assessed. The liver was weighed and evaluated using modified Nonalcoholic Steatohepatitis Clinical Research Network histological score system criteria. All diets induced hepatomegaly, but only HFC-TF increased the size of visceral adipose tissue. Trans fat augmented HFC-induced dyslipidemia, and cholesterol was higher and HDL was lower in the HFC-TF groups. Alcohol lowered triglycerides in both dietary groups. HFC elevated ALT and AST, which were lowered by trans fat. All diets induced histological SH, addition of trans fat induced more steatosis but less inflammation. Inclusion of alcohol augmented the HFC-induced inflammation. All diets induced mild fibrosis. Inclusion of trans fat and alcohol significantly increased rPRO-C3. The addition of trans fat reduced the HFC-induced inflammation but augmented steatosis and dyslipidemia. Inclusion of alcohol induced a more inflammatory and fibrogenic phenotype.NEW & NOTEWORTHY Alcoholic liver disease and nonalcoholic liver disease share significant overlap, which suggests the existence of metabolic steatohepatitis. Trans fat has been implicated in steatohepatitis development. Here, we show that the addition of trans fat to an atherogenic diet results in a more steatotic but less inflammatory phenotype, whereas the addition of alcohol to an atherogenic diet augments the inflammatory and fibrogenic properties of the diet.

Limitations of non-invasive tests for assessment of liver fibrosis

The diagnostic assessment of liver injury is an important step in the management of patients with chronic liver disease (CLD). Although liver biopsy is the reference standard for the assessment of necroinflammation and fibrosis, the inherent limitations of an invasive procedure, and need for repeat sampling, have led to the development of several non-invasive tests (NITs) as alternatives to liver biopsy. Such non-invasive approaches mostly include biological (serum biomarker algorithms) or physical (imaging assessment of tissue stiffness) assessments. However, currently available NITs have several limitations, such as variability, inadequate accuracy and risk factors for error, while the development of a newer generation of biomarkers for fibrosis may be limited by the sampling error inherent to the reference standard. Many of the current NITs were initially developed to diagnose significant fibrosis in chronic hepatitis C, subsequently refined for the diagnosis of advanced fibrosis in patients with non-alcoholic fatty liver disease, and further adapted for prognostication in CLD. An important consideration is that despite their increased use in clinical practice, these NITs were not designed to reflect the dynamic process of fibrogenesis, differentiate between adjacent disease stages, diagnose non-alcoholic steatohepatitis, or follow longitudinal changes in fibrosis or disease activity caused by natural history or therapeutic intervention. Understanding the strengths and limitations of these NITs will allow for more judicious interpretation in the clinical context, where NITs should be viewed as complementary to, rather than as a replacement for, liver biopsy.

Pegbelfermin (BMS-986036): an investigational PEGylated fibroblast growth factor 21 analogue for the treatment of nonalcoholic steatohepatitis

Introduction: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide and is strongly associated with obesity and insulin resistance. NAFLD refers to a spectrum of disorders ranging from asymptomatic hepatic steatosis (nonalcoholic fatty liver, NAFL) to nonalcoholic steatohepatitis (NASH), which increases the risk of developing more severe forms of liver disease such as progressive fibrosis, cirrhosis, and liver cancer. Currently, there are no food and drug administration (FDA) approved drugs to treat NASH. Pegbelfermin (BMS-986036) is a PEGylated fibroblast growth factor 21 (FGF21) analogue that is under investigation for the treatment of NASH.Areas covered: We reviewed the (pre)clinical pegbelfermin studies and compared these with other studies that assessed FGF21 and FGF21 analogues in the treatment of NASH.Expert opinion: With no FDA approved treatments available for NASH, there is an urgent need for novel therapies. Pegbelfermin is a systemic treatment with pleiotropic effects on various tissues. Short-term adverse effects are limited, but more research is required to study potential long-term safety issues. In a phase 2a trial, pegbelfermin has shown promising improvements in several NASH related outcomes. However, clinical trials demonstrating long-term benefits on hard outcomes such as liver histology, cirrhosis development, or survival are required for further validation.

Confounding factors of non-invasive tests for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) affects at least 25% of the general adult population worldwide. Because only a fraction of the patients would develop liver-related complications, it is preferable to perform non-invasive tests as the initial assessment. This review summarizes the known and potential confounding factors that affect the performance of non-invasive tests of hepatic steatosis and fibrosis in patients with NAFLD. Clinicians may apply the knowledge and exercise caution in selecting investigations and interpreting test results when confounding factors are present.

Genetic contributions to NAFLD: leveraging shared genetics to uncover systems biology

Nonalcoholic fatty liver disease (NAFLD) affects around a quarter of the global population, paralleling worldwide increases in obesity and metabolic syndrome. NAFLD arises in the context of systemic metabolic dysfunction that concomitantly amplifies the risk of cardiovascular disease and diabetes. These interrelated conditions have long been recognized to have a heritable component, and advances using unbiased association studies followed by functional characterization have created a paradigm for unravelling the genetic architecture of these conditions. A novel perspective is to characterize the shared genetic basis of NAFLD and other related disorders. This information on shared genetic risks and their biological overlap should in future enable the development of precision medicine approaches through better patient stratification, and enable the identification of preventive and therapeutic strategies. In this Review, we discuss current knowledge of the genetic basis of NAFLD and of possible pleiotropy between NAFLD and other liver diseases as well as other related metabolic disorders. We also discuss evidence of causality in NAFLD and other related diseases and the translational significance of such evidence, and future challenges from the study of genetic pleiotropy.

Plasma N-terminal propeptide of type III procollagen accurately predicts liver fibrosis severity in children with non-alcoholic fatty liver disease

BACKGROUND & AIMS

We examined the diagnostic performance of plasma N-terminal propeptide of type III procollagen (PIIINP) levels, aspartate aminotransferase to platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score for predicting non-alcoholic steatohepatitis (NASH) and liver fibrosis stage in children/adolescents with non-alcoholic fatty liver disease (NAFLD).

METHODS

We enrolled 204 children/adolescents with biopsy-proven NAFLD at the "Bambino Gesù" Children's Hospital. We measured plasma PIIINP levels using a commercially available enzyme-linked immunosorbent assay kit and calculated APRI and FIB-4 scores using standard methods.

RESULTS

Children with NASH had higher plasma PIIINP levels, APRI and FIB-4 scores compared with those without NASH (all P < .001). However, PIIINP levels had much better diagnostic performance and accuracy than APRI and FIB-4 scores for predicting liver fibrosis stage. PIIINP levels correlated with the total NAFLD activity score (NAS) and its constituent components (P < .0001). The risk of either NASH or F ≥ 2 fibrosis progressively increased with increasing PIIINP levels (P < .0001), independent of age, gender, adiposity measures, insulin resistance, NAS score and the patatin-like phospholipase domain-containing protein-3 rs738409 polymorphism. For every 3.6 ng/mL increase in PIIINP levels, the likelihood of having F ≥ 2 fibrosis increased by ~14-fold (adjusted-odds ratio 14.1, 95% CI 5.50-35.8, P < .0001) after adjustment for the aforementioned risk factors. The area under the receiver operating characteristics curve was 0.921 (95% CI 0.87-0.97) for F ≥ 2 fibrosis, and 0.993 (95% CI 0.98-1.0) for F3 fibrosis respectively.

CONCLUSIONS

Unlike APRI and FIB-4 scores, plasma PIIINP levels are a promising, non-invasive biomarker for diagnosing liver fibrosis stage in children/adolescents with biopsy-proven NAFLD.