The severity of steatosis influences liver stiffness measurement in patients with nonalcoholic fatty liver disease

Imaging-based noninvasive liver disease assessment for staging liver fibrosis in chronic liver disease: A systematic review supporting the AASLD Practice Guideline

BACKGROUND AND AIMS

Transient elastography (TE), shear wave elastography, and/or magnetic resonance elastography (MRE), each providing liver stiffness measurement (LSM), are the most studied imaging-based noninvasive liver disease assessment (NILDA) techniques. To support the American Association for the Study of Liver Diseases guidelines on NILDA, we summarized the evidence on the accuracy of these LSM methods to stage liver fibrosis (F).

APPROACH AND RESULTS

A comprehensive search for studies assessing LSM by TE, shear wave elastography, or MRE for the identification of significant fibrosis (F2-4), advanced fibrosis (F3-4), or cirrhosis (F4), using histopathology as the standard of reference by liver disease etiology in adults or children from inception to April 2022 was performed. We excluded studies with <50 patients with a single disease entity and mixed liver disease etiologies (with the exception of HCV/HIV coinfection). Out of 9447 studies, 240 with 61,193 patients were included in this systematic review. In adults, sensitivities for the identification of F2-4 ranged from 51% to 95%, for F3-4 from 70% to 100%, and for F4 from 60% to 100% across all techniques/diseases, whereas specificities ranged from 36% to 100%, 74% to 100%, and 67% to 99%, respectively. The largest body of evidence available was for TE; MRE appeared to be the most accurate method. Imaging-based NILDA outperformed blood-based NILDA in most comparisons, particularly for the identification of F3-4/F4. In the pediatric population, imaging-based NILDA is likely as accurate as in adults.

CONCLUSIONS

LSM from TE, shear wave elastography, and MRE shows acceptable to outstanding accuracy for the detection of liver fibrosis across various liver disease etiologies. Accuracy increased from F2-4 to F3-4 and was the highest for F4. Further research is needed to better standardize the use of imaging-based NILDA, particularly in pediatric liver diseases.

Association between Bioelectrical Impedance Parameters, Magnetic Resonance Imaging Muscle Parameters, and Fatty Liver Severity in Children and Adolescents

Background/Aims

To evaluate the associations between pediatric fatty liver severity, bioelectrical impedance analysis (BIA), and magnetic resonance imaging parameters, including total psoas muscle surface area (tPMSA) and paraspinal muscle fat (PMF).

Methods

Children and adolescents who underwent BIA and liver magnetic resonance imaging between September 2022 and November 2023 were included. Linear regression analyses identified predictors of liver proton density fat fraction (PDFF) including BIA parameters, tPMSA, and PMF. Ordinal logistic regression analysis identified the association between these parameters and fatty liver grades. Pearson's correlation coefficients were used to evaluate the relationships between tPMSA and muscle-related BIA parameters, and between PMF and fat-related BIA parameters.

Results

Overall, 74 participants aged 8 to 16 years were included in the study. In the linear regression analyses, the percentage of body fat was positively associated with PDFF in all participants, whereas muscle-related BIA parameters were negatively associated with PDFF in participants with obesity. PMF and the PMF index were positively associated with PDFF in normalweight and overweight participants. In the ordinal logistic regression, percentage of body fat was positively associated with fatty liver grade in normal-weight and overweight participants and those with obesity, whereas muscle-related BIA parameters were negatively associated with fatty liver grade in participants with obesity. The PMF index was positively associated with fatty liver grade in normal/overweight participants. In the Pearson correlation analysis, muscle-related BIA parameters were correlated with tPMSA, and the fat-related BIA parameters were correlated with PMF.

Conclusions

BIA parameters and PMF are potential screening tools for assessing fatty liver in children.

FibroScan Discordance With Liver Biopsy Significantly Overestimates Advanced Fibrosis and Cirrhosis in MASLD Subjects With Class 3 Obesity: Implications for Resmetirom Eligibility

GOALS

To investigate the effect of obesity on the stages of fibrosis discordance between FibroScan and liver biopsy.

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the leading cause of liver disease worldwide. Accurate fibrosis assessment is essential in MASLD patients for prognosis and treatment. Vibration-controlled transient elastography using FibroScan can overestimate liver fibrosis in obese patients.

STUDY

This retrospective study included 245 MASLD patients who underwent FibroScan and liver biopsy. Participants were included with FibroScan controlled attenuation parameter (CAP) 250+, 10 liver stiffness measurements (LSM) with IQR/med ≤30%, and 10+ portal tracts on biopsy. Discordance was defined as a ≥2 stage difference between FibroScan and liver biopsy. Participants were stratified by BMI and obesity class to assess their association with discordance. We conducted a post hoc analysis to determine the implication of discordance on resmetirom eligibility. Data was entered into SPSS v28.

RESULTS

Among 245 patients, 29.4% exhibited a ≥2 stage discordance between FibroScan and biopsy. Class 3 obesity was significantly associated with discordance (38.6%) compared with class 2 obesity (24.6%) and class 0 to 1 obesity (18.4%). FibroScan suggested cirrhosis in 66 (57.9%) participants with class 3 obesity, however, liver biopsy confirmed cirrhosis in only 16 (24.2%) subjects and identified 28 (42.4%) subjects with stages 2 to 3 fibrosis, making them potentially eligible for resmetirom.

CONCLUSIONS

FibroScan significantly overestimates advanced fibrosis and cirrhosis in class 3 obesity. A second noninvasive test is warranted for accurate liver-directed therapeutic allocation and to minimize unnecessary biopsies in MASLD management.

Evaluation of Liver Fibrosis through Noninvasive Tests in Steatotic Liver Disease

Liver fibrosis, a critical predictor of the prognosis of metabolic dysfunction-associated steatotic liver disease (MASLD), is traditionally diagnosed via biopsy. Nevertheless, non-invasive alternatives, such as serum biomarkers, vibration-controlled transient elastography, and magnetic resonance elastography, have become prominent because of the limitations of biopsies. Serum biomarkers, such as fibrosis-4 index and NFS Score, are also used widely, offering reliable diagnostic performance for advanced fibrosis. Vibration-controlled transient elastography and shear wave elastography provide further non-invasive evaluations with high diagnostic accuracy, particularly for advanced fibrosis, but the results may be affected by factors such as obesity. Magnetic resonance elastography, with superior diagnostic accuracy and operator independence, is a promising method, but its high cost and limited availability restrict its widespread use. Emerging algorithms, such as NIS4, FAST, or MAST score, have strong potential in identifying high-risk metabolic dysfunction-associated steatohepatitis patients. The integration of multiple non-invasive methods can optimize diagnostic accuracy, reducing the need for invasive biopsies while identifying patients at risk of liver-related complications. Further research is needed to refine these diagnostic tools and improve accessibility.

Impact of hepatic steatosis on liver stiffness measurement by vibration-controlled transient elastography and its diagnostic performance for identifying liver fibrosis in patients with chronic hepatitis B

OBJECTIVES

To explore the impact of hepatic steatosis measured by MRI-proton density fat fraction (MRI-PDFF) on liver stiffness measurement (LSM) value and its diagnostic performance for staging liver fibrosis in patients with chronic hepatitis B (CHB).

METHODS

A total of 914 patients with CHB who underwent liver biopsy and MRI-PDFF were retrospectively reviewed. The influence of MRI-PDFF on LSM value was assessed using univariate and multivariate linear analyses. To assess the influence of liver steatosis on the diagnostic performance of LSM, a series of ROC analyses were performed and compared by stratifying patients into non-steatosis (PDFF < 5%) and steatosis (PDFF ≥ 5%) groups according to MRI-PDFF values. The effects of different LSM cut-off values on the false-positive rate in the steatosis cohort were compared using McNemar's test.

RESULTS

LSM values were significantly affected by MRI-PDFF in the entire cohort (B-coefficient: 0.003, p < 0.001), F1 cohort (B-coefficient: 0.005, p < 0.001), and F2 cohort (B-coefficient: 0.003, p = 0.002). Hepatic steatosis was not observed to have a significant influence on the ROC curve of LSM for staging liver fibrosis. Compared with using the cut-off values for the CHB cohort, using relatively higher cut-off values for hepatic steatosis significantly improved the false-positive rate of LSM in the steatosis cohort.

CONCLUSION

Steatosis significantly influenced LSM, with a higher value in the early stage of liver fibrosis but did not affect the diagnostic efficiency of LSM for staging liver fibrosis. Moreover, using relatively high cut-off values significantly improved the false-positive rate of LSM in CHB patients with steatosis.

CLINICAL RELEVANCE STATEMENT

The identified correlation between MRI-PDFF and VCTE-measured LSM is not clinically relevant since the diagnostic performance of LSM in staging liver fibrosis is not affected by steatosis. A higher cut-off should be applied in CHB patients with steatosis to improve the false-positive rate.

KEY POINTS

Steatosis can affect liver stiff measurement (LSM) values in the early stage of liver fibrosis. The diagnostic performance of LSM in staging liver fibrosis is not affected by steatosis. LSM's cutoffs should be increased in patients with steatosis to improve the false-positive rate.

Comparative diagnostic efficacy of two-dimensional shear wave and transient elastography in predicting the risk of esophagogastric varices and histological staging in patients with primary biliary cholangitis

BACKGROUND

This study aimed to compare the diagnostic efficacy of Two-dimensional shear wave elastography (2D-SWE) with that of transient elastography (TE) in predicting the risk of esophagogastric varices and histological staging in patients with primary biliary cholangitis (PBC).

METHODS

This single-center prospective study enrolled the patients with PBC diagnosed by liver biopsy following 2D-SWE and TE. Receiver operating characteristic (ROC) curves were constructed for SWE-liver stiffness measurement (LSM) and TE-LSM to assess their diagnostic efficacy for histological staging ≥ stage 2, ≥ stage 3, and = stage 4. The diagnostic efficacy and accuracy of SWE-LSM were compared with those of the Baveno VI criteria for detecting esophagogastric varices. Additionally, the impact of different laboratory parameters on SWE-LSM was analyzed.

RESULTS

We evaluated 77 patients (median age, 52 years (range: 16 - 75 years), 66 females). ROC curves constructed using TE-LSM and SWE-LSM demonstrated similar diagnostic efficacy for histological staging ≥ stage 2 (area under the curve [AUC]: 0.824 vs. 0.823 for TE-LSM and SWE-LSM, respectively, p = 0.9764), ≥ stage 3 (AUC: 0.918 vs. 0.907 for TE-LSM and SWE-LSM, respectively, p = 0.6443), and = stage 4 (AUC: 0.907 vs. 0.902 for TE-LSM and SWE-LSM, respectively, p = 0.8763). Additionally, while there was no significant difference in the diagnostic efficacy between the two methods for detecting esophagogastric varices (Z = 1.516, p = 0.1296), 2D-SWE had a slightly higher diagnostic accuracy than TE (61.8% vs. 76.4%). Transaminases and bilirubin levels had little influence on SWE-LSM.

CONCLUSION

2D-SWE exhibited comparable performance to TE in predicting the risk of esophagogastric varices and histological staging.

Implementation of Machine Learning Algorithms to Screen for Advanced Liver Fibrosis in Metabolic Dysfunction-Associated Steatotic Liver Disease: An In-Depth Explanatory Analysis

INTRODUCTION

This study aimed to train machine learning algorithms (MLAs) to detect advanced fibrosis (AF) in metabolic dysfunction-associated steatotic liver disease (MASLD) patients at the level of primary care setting and to explain the predictions to ensure responsible use by clinicians.

METHODS

Readily available features of 618 MASLD patients followed up at a tertiary center were used to train five MLAs. AF was defined as liver stiffness ≥9.3 kPa, measured via 2-dimension shear wave elastography (n = 495) or liver biopsy ≥F3 (n = 123). MLAs were compared to Fibrosis-4 index (FIB-4) and non-alcoholic fatty liver disease (NAFLD) fibrosis score (NFS) on 540 MASLD patients from the primary care setting as validation. Feature importance, partial dependence, and shapely additive explanations (SHAPs) were utilized for explanation.

RESULTS

Extreme gradient boosting (XGBoost) achieved an AUC = 0.91, outperforming FIB-4 (AUC = 0.78) and NFS (AUC = 0.81, both p < 0.05) with specificity = 76% versus 59% and 48% for FIB-4 ≥1.3 and NFS ≥-1.45, respectively (p < 0.05). Its sensitivity (91%) was superior to FIB-4 (79%). XGBoost confidently excluded AF (negative predictive value = 99%) with the highest positive predictive value (31%), superior to FIB-4 and NFS (all p < 0.05). The most important features were HbA1c and gamma glutamyl transpeptidase (GGT) with a steep increase in AF probability at HbA1c >6.5%. The strongest interaction was between AST and age. XGBoost, but not logistic regression, extracted informative patterns from ALT, low-density lipoprotein cholesterol, and alkaline phosphatase (p < 0.001). One-quarter of the false positives (FPs) were correctly reclassified with only one additional false negative based on the SHAP values of GGT, platelets, and ALT which were found to be associated with a FP classification.

CONCLUSIONS

An explainable XGBoost algorithm was demonstrated superior to FIB-4 and NFS for screening of AF in MASLD patients at the primary care setting. The algorithm also proved safe for use as clinicians can understand the predictions and flag FP classifications.

WFUMB Guidelines/Guidance on Liver Multiparametric Ultrasound. Part 2: Guidance on Liver Fat Quantification

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has promoted the development of this document on multiparametric ultrasound. Part 2 is a guidance on the use of the available tools for the quantification of liver fat content with ultrasound. These are attenuation coefficient, backscatter coefficient, and speed of sound. All of them use the raw data of the ultrasound beam to estimate liver fat content. This guidance has the aim of helping the reader in understanding how they work and interpret the results. Confounding factors are discussed and a standardized protocol for measurement acquisition is suggested to mitigate them. The recommendations were based on published studies and experts' opinion but were not formally graded because the body of evidence remained low at the time of drafting this document.

WFUMB Guideline/Guidance on Liver Multiparametric Ultrasound: Part 1. Update to 2018 Guidelines on Liver Ultrasound Elastography

The World Federation for Ultrasound in Medicine and Biology (WFUMB) endorsed the development of this document on multiparametric ultrasound. Part 1 is an update to the WFUMB Liver Elastography Guidelines Update released in 2018 and provides new evidence on the role of ultrasound elastography in chronic liver disease. The recommendations in this update were made and graded using the Oxford classification, including level of evidence (LoE), grade of recommendation (GoR) and proportion of agreement (Oxford Centre for Evidence-Based Medicine [OCEBM] 2009). The guidelines are clinically oriented, and the role of shear wave elastography in both fibrosis staging and prognostication in different etiologies of liver disease is discussed, highlighting advantages and limitations. A comprehensive section is devoted to the assessment of portal hypertension, with specific recommendations for the interpretation of liver and spleen stiffness measurements in this setting.

The effect of weight gain and metabolic dysfunction-associated steatotic liver disease on liver fibrosis progression and regression in people with HIV

OBJECTIVE

People with HIV (PWH) have high risk of liver fibrosis. We investigated the effect of weight gain and metabolic dysfunction-associated steatotic liver disease (MASLD) on liver fibrosis dynamics.

DESIGN

Multicenter cohort study.

METHODS

Fibrosis progression was defined as development of significant fibrosis [liver stiffness measurement (LSM) ≥8 kPa], or transition to cirrhosis (LSM ≥13 kPa), for those with significant fibrosis at baseline. Fibrosis regression was defined as transition to LSM less than 8 kPa, or to LSM less than 13 kPa for those with cirrhosis at baseline. MASLD was defined as hepatic steatosis (controlled attenuation parameter >248 dB/m) with at least one metabolic abnormality. A continuous-time multistate Markov model was used to describe transitions across fibrosis states.

RESULTS

Among 1183 PWH included from three centers (25.2% with viral hepatitis coinfection), baseline prevalence of significant fibrosis and MASLD was 14.4 and 46.8%, respectively. During a median follow-up of 2.5 years (interquartile range 1.9-3.5), the incidence rate of fibrosis progression and regression was 2.8 [95% confidence interval (CI) 2.3-3.4] and 2.2 (95% CI 1.9-2.6) per 100 person-years, respectively. In Markov model, weight gain increased the odds of fibrosis progression [odds ratio (OR) 3.11, 95% CI 1.59-6.08], whereas weight gain (OR 0.30, 95% CI 0.10-0.84) and male sex (OR 0.32, 95% CI 0.14-0.75) decreased the odds of fibrosis regression. On multivariable Cox regression analysis, predictors of fibrosis progression were weight gain [adjusted hazard ratio (aHR) 3.12, 95% CI 1.41-6.90] and MASLD (aHR 2.72, 95% CI 1.05-7.02).

CONCLUSION

Fibrosis transitions are driven by metabolic health variables in PWH, independently of viral hepatitis coinfection and antiretroviral class therapy.

The Effect of Steatosis on Shear-Wave Velocity and Viscoelastic Properties Related to Liver Fibrosis Progression in Rat Models

OBJECTIVE

Hepatic fibrosis has recently been evaluated using ultrasonography or magnetic resonance elastography. Although the shear wave velocity (SWV) obtained using point shear wave elastography (pSWE) provides a valuable measure of fibrosis, underlying steatosis may affect its measurement.

METHODS

Using hepatic fibrosis samples, this study evaluated the effect of steatosis on the shear wave velocity of pSWE (Vs) and viscoelastic properties (assessed by dynamic mechanical analysis) of rat liver. Fifty rats with various grades of steatosis and fibrosis underwent open abdominal in vivo Vs measurements using a commercial ultrasound scanner. The mechanical properties of hepatic tissue were also characterized under ex vivo conditions using dynamic mechanical analysis and the Zener model of viscoelasticity.

RESULTS

Fibrosis and steatosis progression influenced Vs and elasticity. The SWV computed using the Zener model and Vs showed a substantial correlation (r > 0.8). Fibrosis progression increased SWV. Steatosis was also related to SWV. Steatosis progression obscured the SWV change associated with fibrosis progression.

CONCLUSION

We conclude that steatosis progression affects the evaluation of fibrosis progression. This finding could aid discrimination of non-alcoholic steatohepatitis from non-alcoholic fatty liver disease using SWV.

Non-invasive testing and risk-stratification in patients with MASLD

The development and validation of non-invasive fibrosis tests (NITs) has changed clinical practice in Hepatology over the last 15 years. Metabolic associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease in western countries, with up to a third of the unselected adult population affected. In this article, we review the use of NITs in the diagnosis and staging of MASLD. We discuss their use in the diagnosis of steatosis, steatohepatitis and fibrosis and critically evaluate recently published data. These NITs include a variety of approaches, such as serum markers like FIB-4, pro-C3 and ELF, imaging techniques like Fibroscan® and MRE, and combined scores like Agile 3+ and Agile 4, offering a range of options for healthcare providers. Furthermore, these non-invasive tests also serve as valuable prognostic tools, allowing for better risk assessment and improved patient management, particularly in predicting liver-related events and overall mortality.

Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race

OBJECTIVE

The objective of this study was to assess the performance of noninvasive tests (NITs) across different racial and ethnic groups in a large multiethnic cohort.

METHODS

Data were derived from the National Health and Nutrition Examination Survey (NHANES) 2017 through 2020. Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study.

RESULTS

Among the 6359 adults included in the study, fatty liver index and nonalcoholic fatty liver disease liver fat scores performed well for the prediction of metabolic dysfunction-associated steatotic liver disease, without significant changes across racial and ethnic groups. However, significant differences were observed across racial and ethnic groups for the prediction of advanced fibrosis and cirrhosis. The fibrosis-4 (FIB-4) index, aspartate aminotransferase to platelet ratio index (APRI), and nonalcoholic fatty liver disease fibrosis score underperformed in non-Hispanic Black patients for the detection of cirrhosis. For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI. Using a cutoff point of 12 kPa for advanced fibrosis, both APRI and the FIB-4 index performed significantly worse in non-Hispanic Black patients.

CONCLUSIONS

In a large, diverse national cohort, the performance of NITs was overall poor compared with transient elastography, and NITs showed differences across racial and ethnic groups. Given the widespread use of NITs, it is imperative that the scores are equitable across racial and ethnic groups.

Brazilian evidence-based guideline for screening, diagnosis, treatment, and follow-up of metabolic dysfunction-associated steatotic liver disease (MASLD) in adult individuals with overweight or obesity: A joint position statement from the Brazilian Society of Endocrinology and Metabolism (SBEM), Brazilian Society of Hepatology (SBH), and Brazilian Association for the Study of Obesity and Metabolic Syndrome (Abeso)

Introduction

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as Nonalcoholic fatty liver disease (NAFLD), is one of the most common hepatic diseases in individuals with overweight or obesity. In this context, a panel of experts from three medical societies was organized to develop an evidence-based guideline on the screening, diagnosis, treatment, and follow-up of MASLD.

Material and methods

A MEDLINE search was performed to identify randomized clinical trials, meta-analyses, cohort studies, observational studies, and other relevant studies on NAFLD. In the absence of studies on a certain topic or when the quality of the study was not adequate, the opinion of experts was adopted. Classes of Recommendation and Levels of Evidence were determined using prespecified criteria.

Results

Based on the literature review, 48 specific recommendations were elaborated, including 11 on screening and diagnosis, 9 on follow-up,14 on nonpharmacologic treatment, and 14 on pharmacologic and surgical treatment.

Conclusion

A literature search allowed the development of evidence-based guidelines on the screening, diagnosis, treatment, and follow-up of MASLD in individuals with overweight or obesity.

Non-Invasive Diagnostic of NAFLD in Type 2 Diabetes Mellitus and Risk Stratification: Strengths and Limitations

The progressive potential of liver damage in type 2 diabetes mellitus (T2DM) towards advanced fibrosis, end-stage liver disease, and hepatocarcinoma has led to increased concern for quantifying liver injury and individual risk assessment. The combination of blood-based markers and imaging techniques is recommended for the initial evaluation in NAFLD and for regular monitoring to evaluate disease progression. Continued development of ultrasonographic and magnetic resonance imaging methods for accurate quantification of liver steatosis and fibrosis, as well as promising tools for the detection of high-risk NASH, have been noted. In this review, we aim to summarize available evidence regarding the usefulness of non-invasive methods for the assessment of NAFLD in T2DM. We focus on the power and limitations of various methods for diagnosis, risk stratification, and patient monitoring that support their implementation in clinical setting or in research field.

Portal Hypertension in Nonalcoholic Fatty Liver Disease: Challenges and Paradigms

Portal hypertension in cirrhosis is defined as an increase in the portal pressure gradient (PPG) between the portal and hepatic veins and is traditionally estimated by the hepatic venous pressure gradient (HVPG), which is the difference in pressure between the free-floating and wedged positions of a balloon catheter in the hepatic vein. By convention, HVPG≥10 mmHg indicates clinically significant portal hypertension, which is associated with adverse clinical outcomes. Nonalcoholic fatty liver disease (NAFLD) is a common disorder with a heterogeneous clinical course, which includes the development of portal hypertension. There is increasing evidence that portal hypertension in NAFLD deserves special considerations. First, elevated PPG often precedes fibrosis in NAFLD, suggesting a bidirectional relationship between these pathological processes. Second, HVPG underestimates PPG in NAFLD, suggesting that portal hypertension is more prevalent in this condition than currently believed. Third, cellular mechanoresponses generated early in the pathogenesis of NAFLD provide a mechanistic explanation for the pressure-fibrosis paradigm. Finally, a better understanding of liver mechanobiology in NAFLD may aid in the development of novel pharmaceutical targets for prevention and management of this disease.

Changing Trends in Liver Biopsy Practices: A Single-Center Analysis

Introduction To assess the trends for liver biopsy (LB) indications, technique, and histopathologic diagnosis, we retrospectively evaluated liver biopsies in two one-year periods, separated by a decade. Methods A pathology database query was performed for all parenchymal LB in patients over 18 years (11/2017 to 10/2018) and compared to those performed over a one-year period, a decade ago. We identified 427 parenchymal liver biopsies in the recent group and 166 in the decade-old group. Results Elevated liver enzymes are the most common indication for LB. Non-alcoholic fatty liver disease (NAFLD) has become the most common diagnosis compared to 10 years ago, when it was viral hepatitis. Routes of LB were significantly different between the two groups, endoscopic ultrasound-guided liver biopsy (EUS-LB) (80.3% vs 0; p<0.0001), computed tomography-guided (0 vs 42.8%, p<0.0001), percutaneous by gastroenterologists (0% vs 29.5%, p<0.0001), and transjugular-LB (15.1% vs 17.6%, p<0.0001). The adequacy of the tissue for pathological diagnosis was similar, and there was no difference in adverse events. Conclusion At our institution, practice patterns have changed significantly for liver biopsy. There has been an increase in liver biopsy volume, and EUS guidance has become the most common approach for liver biopsy.

Steatotic Liver Disease: Metabolic Dysfunction, Alcohol, or Both?

Non-alcoholic fatty liver disease (NAFLD) and alcohol-related liver disease (ALD), both of them accounting for fatty liver disease (FLD), are among the most common chronic liver diseases globally, contributing to substantial public health burden. Both NAFLD and ALD share a similar picture of clinical presentation yet may have differences in prognosis and treatment, which renders early and accurate diagnosis difficult but necessary. While NAFLD is the fastest increasing chronic liver disease, the prevalence of ALD has seemingly remained stable in recent years. Lately, the term steatotic liver disease (SLD) has been introduced, replacing FLD to reduce stigma. SLD represents an overarching term to primarily comprise metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), as well as alcohol-related liver disease (ALD), and MetALD, defined as a continuum across which the contribution of MASLD and ALD varies. The present review discusses current knowledge on common denominators of NAFLD/MASLD and ALD in order to highlight clinical and research needs to improve our understanding of SLD.

Local fat content determines global and local stiffness in livers with simple steatosis

Fat accumulation during liver steatosis precedes inflammation and fibrosis in fatty liver diseases, and is associated with disease progression. Despite a large body of evidence that liver mechanics play a major role in liver disease progression, the effect of fat accumulation by itself on liver mechanics remains unclear. Thus, we conducted ex vivo studies of liver mechanics in rodent models of simple steatosis to isolate and examine the mechanical effects of intrahepatic fat accumulation, and found that fat accumulation softens the liver. Using a novel adaptation of microindentation to permit association of local mechanics with microarchitectural features, we found evidence that the softening of fatty liver results from local softening of fatty regions rather than uniform softening of the liver. These results suggest that fat accumulation itself exerts a softening effect on liver tissue. This, along with the localized heterogeneity of softening within the liver, has implications in what mechanical mechanisms are involved in the progression of liver steatosis to more severe pathologies and disease. Finally, the ability to examine and associate local mechanics with microarchitectural features is potentially applicable to the study of the role of heterogeneous mechanical microenvironments in both other liver pathologies and other organ systems.

How to Identify Advanced Fibrosis in Adult Patients with Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH) Using Ultrasound Elastography-A Review of the Literature and Proposed Multistep Approach

Non-alcoholic fatty liver disease (NAFLD), and its progressive form, non-alcoholic steatohepatitis (NASH), represent, nowadays, real challenges for the healthcare system. Liver fibrosis is the most important prognostic factor for NAFLD, and advanced fibrosis is associated with higher liver-related mortality rates. Therefore, the key issues in NAFLD are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. We critically reviewed the ultrasound (US) elastography techniques for the quantitative characterization of fibrosis, steatosis, and inflammation in NAFLD and NASH, with a specific focus on how to differentiate advanced fibrosis in adult patients. Vibration-controlled transient elastography (VCTE) is still the most utilized and validated elastography method for liver fibrosis assessment. The recently developed point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) techniques that use multiparametric approaches could bring essential improvements to diagnosis and risk stratification.

Diagnostic efficiency on ultrasound shear wave elastography in evaluation of steatosis severity for non-alcoholic fatty liver disease: a rat model

BACKGROUND

The pathological feature of steatosis affects the elasticity values measured by shear wave elastography (SWE) is still controversial in non-alcoholic fatty liver disease (NAFLD). The aim of this study is to demonstrate the influence of steatosis on liver stiffness measured by SWE on a rat model with NAFLD and analyze feasibility of SWE for grading steatosis in absence of fibrosis.

METHODS

Sixty-six rats were fed with methionine choline deficient diet or standard diet to produce various stages of steatosis; 48 rats were available for final analysis. Rats underwent abdominal ultrasound SWE examination and pathological assessment. Liver histopathology was analyzed to assess the degree of steatosis, inflammation, ballooning, and fibrosis according to the non-alcoholic fatty liver disease activity score. The diagnostic performance of SWE for differentiating steatosis stages was estimated according to the receiver operating characteristic (ROC) curve. Decision curve analysis (DCA) was conducted to determine clinical usefulness and the areas under DCA (AUDCAs) calculated.

RESULTS

In multivariate analysis, steatosis was an independent factor affecting the mean elastic modules (B = 1.558, P < 0.001), but not inflammation (B =  - 0.031, P = 0.920) and ballooning (B = 0.216, P = 0.458). After adjusting for inflammation and ballooning, the AUROC of the mean elasticity for identifying S ≥ S1 was 0.956 (95%CI: 0.872-0.998) and the AUDCA, 0.621. The AUROC for distinguishing S ≥ S2 and S = S3 was 0.987 (95%CI: 0.951-1.000) and 0.920 (95%CI: 0.816-0.986) and the AUDCA was 0.506 and 0.256, respectively.

CONCLUSIONS

Steatosis is associated with liver stiffness and SWE may have the feasibility to be introduced as an assistive technology in grading steatosis for patients with NAFLD in absence of fibrosis.

Liver fat accumulation more than fibrosis causes early liver dynamic dysfunction in patients with non-alcoholic fatty liver disease

INTRODUCTION

In Non-Alcoholic Fatty Liver Disease (NAFLD), events driving early hepatic dysfunction with respect to specific metabolic pathways are still poorly known.

METHODS

We enrolled 84 subjects with obesity and/or type 2 diabetes (T2D). FibroScan® served to assess NAFLD by controlled attenuation parameter (CAP), and fibrosis by liver stiffness (LS). Patients with LS above 7 kPa were excluded. APRI and FIB-4 were used as additional serum biomarkers of fibrosis. The stable-isotope dynamic breath test was used to assess the hepatic efficiency of portal extraction (as DOB₁₅) and microsomal metabolization (as cPDR₃₀) of orally-administered (¹³C)-methacetin.

RESULTS

NAFLD occurred in 45%, 65.9%, and 91.3% of normal weight, overweight, and obese subjects, respectively. Biomarkers of liver fibrosis were comparable across subgroups, and LS was higher in obese, than in normal weight subjects. DOB₁₅ was 23.2 ± 1.5‰ in normal weight subjects, tended to decrease in overweight (19.9 ± 1.0‰) and decreased significantly in obese subjects (16.9 ± 1.3, P = 0.008 vs. normal weight). Subjects with NAFLD had lower DOB₁₅ (18.7 ± 0.9 vs. 22.1 ± 1.2, P = 0.03) but higher LS (4.7 ± 0.1 vs. 4.0 ± 0.2 kPa, P = 0.0003) than subjects without NAFLD, irrespective of fibrosis. DOB₁₅ (but not cPDR₃₀) decreased with increasing degree of NAFLD (R = -0.26; P = 0.01) and LS (R = -0.23, P = 0.03). Patients with T2D showed increased rate of NAFLD than those without T2D but similar LS, DOB₁₅ and cPDR₃₀.

CONCLUSIONS

Overweight, obesity and liver fat accumulation manifest with deranged portal extraction efficiency of methacetin into the steatotic hepatocyte. This functional alteration occurs early, and irrespective of significant fibrosis and presence of T2D.

Effects of SGLT2 inhibitors on hepatic fibrosis and steatosis: A systematic review and meta-analysis

OBJECTIVE

Clinical trials have shown that sodium-glucose cotransporter 2 inhibitors (SGLT2i) are closely associated with hepatic fibrosis and steatosis by FibroScan. This paper aimed at evaluating the effects of SGLT2i on hepatic fibrosis and steatosis, which are presented as liver stiffness measurement (LSM) and controlled attenuation parameter (CAP).

METHODS

PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, China Science and Technology Journal Database, and Wanfang Database were searched for randomized clinical trials from database establishment to 30 November 2022 with no language restrictions. The risk of bias was evaluated by Collaboration Handbook. Software Stata 17 and Review Manager (version 5.3) were used for meta-analysis.

RESULTS

A total of eight articles including 686 patients were included. Compared with the control group, our results showed that SGLT2i could lower levels of LSM [MD = -0.82, 95%CI (-1.38, -0.25), p = 0.005] and CAP [MD = -12.80, 95%CI (-20.57, -5.03), p = 0.001]. Further subgroup analyses indicated that SGLT2i presented more advantages on longer treatment duration and more serious steatosis in decreasing LSM. For CAP, SGLT2i exhibited a clear advantage in subgroup analyses of longer treatment duration, younger people, dapagliflozin, worse fibrosis, and steatosis.

CONCLUSION

SGLT2i could reduce LSM and CAP in contrast to other antihyperglycemic drugs. However, the included studies are not definitive, and well-designed, more multi-centered, blinded randomized clinical trials are warranted to definitively establish reliable evidence.

Non-invasive methods to evaluate liver fibrosis in patients with non-alcoholic fatty liver disease

Non-alcoholic Fatty Liver Disease (NAFLD) is a chronic liver disease that is strongly related to insulin resistance and metabolic syndrome, and it has become the most common liver disorder in developed countries. NAFLD embraces the full pathological process of three conditions: steatosis, non-alcoholic steatohepatitis, and finally, cirrhosis. As NAFLD progresses, symptoms will become increasingly severe as fibrosis develops. Therefore, evaluating the fibrosis stage is crucial for patients with NAFLD. A liver biopsy is currently considered the gold standard for staging fibrosis. However, due to the limitations of liver biopsy, non-invasive alternatives were extensively studied and validated in patients with NAFLD. The advantages of non-invasive methods include their high safety and convenience compared with other invasive approaches. This review introduces the non-invasive methods, summarizes their benefits and limitations, and assesses their diagnostic performance for NAFLD-induced fibrosis.

Noninvasive predictors of clinically significant portal hypertension in NASH cirrhosis: Validation of ANTICIPATE models and development of a lab-based model

Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥ 10 mm Hg, identifies patients with compensated cirrhosis at a high risk of decompensation. However, HVPG is an invasive and nuanced method. The ANTICIPATE models, which include liver stiffness measurements by transient elastography (TE) and platelet count ± body mass index, are robust noninvasive surrogates of CSPH but required external validation in patients with nonalcoholic steatohepatitis (NASH) cirrhosis. Additionally, TE is not widely available worldwide. The aims of the study were: (1) to externally validate the ANTICIPATE models using baseline data from patients with compensated NASH cirrhosis screened/enrolled in a multicenter international randomized controlled trial; and (2) to develop and externally validate a model using only laboratory values. Regarding aim 1, both ANTICIPATE models showed good calibration and discrimination (area under the curve [AUC] > 0.8) in our cohort (n = 222). Regarding aim 2, a new lab-based model using the Fibrosis-4 index (FIB-4 [age, aspartate aminotransferase, alanine aminotransferase, platelet count]) plus serum albumin was developed. The discrimination in the training cohort (n = 309) was good (AUC of 0.78 [95% confidence interval [CI]:0.72-0.83]). It was then externally validated in a separate cohort of 245 patients with compensated NASH cirrhosis (AUC of 0.8 [95% CI: 0.75-0.86]). Given the difference in the prevalence of CSPH between training (74%) and validation (39%) cohorts, the model required an update of the baseline risk to achieve a good calibration. The updated model was named FIB4+. In conclusion, both ANTICIPATE models performed well in predicting the presence of CSPH in NASH cirrhosis. A model using FIB-4 plus albumin (FIB4+) can be used to predict CSPH where TE is not available.

Prevalence of fatty liver and advanced fibrosis by ultrasonography and FibroScan in a general population random sample

AIM

Fatty liver is the most common liver disease. This study examined fatty liver and advanced fibrosis prevalence in a random sample of the Japanese general population.

METHODS

A total of 6000 people randomly selected from two cities in Hiroshima Prefecture were invited to participate in this cross-sectional study originally carried out for hepatitis virus screening. Ultrasonography and FibroScan (controlled attenuation parameter [CAP] and liver stiffness measurement [LSM]) were provided as additional tests.

RESULTS

Of 6000 invited individuals, 1043 participated in hepatitis virus screening, of which 488 randomly selected individuals (median age, 56 years; interquartile range, 45-68 years; male participants, 49.8%) underwent ultrasonography, CAP, and LSM. Ultrasonography showed fatty liver in 24.6% and mild fatty liver in 32.8%. Controlled attenuation parameter showed severe steatosis in 27.5%, moderate steatosis in 12.5%, and mild steatosis in 11.1%. Overall, 62.1% were diagnosed with fatty liver based on ultrasonography or CAP. Nonalcoholic fatty liver disease (NAFLD) prevalence was 50.6%. Liver stiffness measurement found cirrhosis in 1.0% and severe fibrosis in 1.8%. Multivariate analysis of risk factors associated with ≥F2 or higher liver fibrosis showed that age ≥60 years and above (adjusted odds ratio [AOR], 3.2; 95% confidence interval [CI], 1.5-6.9; p = 0.0031), hepatitis C virus antibody positivity (AOR, 8.4; 95% CI, 1.0-68.4; p = 0.0467), and fatty liver (AOR, 2.3; 95% CI, 1.1-6.2; p = 0.0317) are independent risk factors.

CONCLUSIONS

In the general population, 62.1% had fatty liver, and NAFLD prevalence was twice as high as previously reported. Screening that is noninvasive, low-cost, and does not require special techniques or equipment is needed to detect advanced liver fibrosis.

Hepatic steatosis leads to overestimation of liver stiffness measurement in both chronic hepatitis B and metabolic-associated fatty liver disease patients

BACKGROUND

The impact of hepatic steatosis on liver stiffness measurement (LSM) in both chronic hepatitis B(CHB) and metabolic-associated fatty liver disease (MAFLD) remains controversial.

AIMS

To determine whether LSM is affected by hepatic steatosis in CHB-MAFLD.

METHODS

Hepatic steatosis and liver fibrosis were assessed by histological and noninvasively methods. The area under the receiver operating characteristic curve (AUROC) was used to evaluate the diagnostic performance of LSM.

RESULTS

The prevalence of MAFLD in CHB patients (n = 436)was 47.5% (n = 207). For patients with low amounts of fibrosis (F0-1 and F0-2), the median LSM was 8.8 kPa and 9.2 kPa in patients with moderate- severe steatosis,which was significantly higher than that in patients with none-mild steatosis (P < 0.05) . The positive predictive value(PPV) was lower for LSM identifying significant fibrosis (F ≥ 2) as well as severe fibrosis (F ≥ 3) in group which controlled attenuation parameter(CAP) ≥ 268 dB/m than its counterpart(68.2% vs 84.6% and 24.3% vs 45.0%). The AUROC of LSM detected F ≥ 2 was 0.833 at a cutoff of 8.8 kPa and 0.873 at a cutoff of 7.0 kPa in patients with CAP ≥ 268 and CAP < 268, respectively.

CONCLUSIONS

The presence of moderate-severe steatosis, detected by histology or CAP, should be taken into account to avoid overestimation of LSM.

Liver Stiffness Measurements by 2D Shear-Wave Elastography: Effect of Steatosis on Fibrosis Evaluation

BACKGROUND. Hepatic steatosis has been found not to affect liver stiffness measurements (LSM) from MR elastography (MRE). However, the effect of steatosis on LSM from 2D shear-wave elastography (SWE) remains controversial. OBJECTIVE. The purpose of this study was to evaluate the effect of hepatic steatosis on the diagnostic performance of LSM from 2D SWE (LSM2D SWE) for evaluation of liver fibrosis with LSM from MRE (LSMMRE) as the reference standard. METHODS. This retrospective study included 888 patients (442 women, 446 men; median age, 67 years) with chronic liver disease who underwent LSM by both 2D SWE and MRE within a 3-month window. Steatosis was also assessed on ultrasound examinations by ultrasound-guided attenuation parameter (UGAP) and on MRI examinations by proton density fat fraction (PDFF). Fibrosis stages and steatosis grades were classified according to previously established thresholds. The effect of steatosis on LSM2D SWE was evaluated by Kruskal-Wallis tests with post hoc tests and ROC analysis. RESULTS. LSM2D SWE were significantly higher in patients with severe steatosis than those without steatosis by MRI PDFF among patients with F0 fibrosis (5.5 kPa [IQR, 4.7-6.0 kPa] vs 4.7 kPa [IQR, 4.2-5.5 kPa], p = .009) and F1 fibrosis (6.3 kPa [IQR, 6.0-7.2 kPa] vs 5.9 kPa [IQR, 5.0-6.6 kPa], p = .009). LSM2D SWE were significantly higher in patients with severe steatosis than those without steatosis by UGAP among patients with F1 fibrosis (6.6 kPa [IQR, 5.9-7.3 kPa] vs 5.9 kPa [IQR, 5.1-6.5 kPa], p = .008). Otherwise, LSM2D SWE did not vary significantly across steatosis grades at a given fibrosis stage (all p > .05). Sensitivity and specificity for ≥ F1 fibrosis were 63.8% and 91.5% in patients without versus 60.4% and 80.9% in patients with severe steatosis by MRI PDFF and were 62.4% and 91.5% in patients without versus 72.1% and 78.3% in patients with severe steatosis by UGAP. CONCLUSION. Severe hepatic steatosis may result in overestimation of LSM2D SWE in patients without or with mild steatosis, reducing the specificity of liver fibrosis detection. CLINICAL IMPACT. Assessment of UGAP at 2D SWE may help identify patients in whom LSM2D SWE should be assessed with caution. In patients with no or mild steatosis by 2D SWE and severe steatosis by UGAP, MRE helps provide a more reliable measure of liver fibrosis.

Quantitative Assessment of Liver Impairment in Chronic Viral Hepatitis with [99mTc]Tc-Mebrofenin: A Noninvasive Attempt to Stage Viral Hepatitis-Associated Liver Fibrosis

Background and objectives—Chronic viral hepatitis B and C infections are one of the leading causes of chronic liver impairment, resulting in liver fibrosis and liver cirrhosis. An early diagnosis with accurate liver fibrosis staging leads to a proper diagnosis, thus tailoring correct treatment. Both invasive and noninvasive techniques are used in the diagnosis and staging of chronic liver impairment. Those techniques include liver biopsy, multiple serological markers (as either single tests or combined panels), and imaging examinations, such as ultrasound or magnetic resonance elastography. Nuclear medicine probes may also be employed in staging liver fibrosis, although the literature scarcely reports this. The purpose of our study was to investigate whether a dynamic liver scintigraphy with [^99mTc]Tc-mebrofenin has any value in staging or grading chronic liver damage. Materials and Methods—We prospectively enrolled patients with chronic viral hepatitis B and C infection referred for liver biopsy. All patient underwent dynamic liver scintigraphy with 99mTc-mebrofenin prior to liver biopsy. Dynamic liver scintigraphy was performed immediately after intravenous tracer injection for 30 min scanning time. Multiple scintigraphy parameters were calculated (whole liver lobe and focal area time to peak (TTP), 30 min to peak ratio (30/peak), whole lobe and focal area slope index in 350 s (slope_350). Liver biopsy took place shortly after imaging. Results—We found that many dynamic scintigraphic parameters are positively or negatively associated with different stages of liver fibrosis. The main parameters that showed most value are the ratio between 30 min and the peak of the dynamic curve (30/peak_dex (ratio)), and liver clearance corrected for body surface area and liver area (LCL_m²_dm² (%/min/m²/dm²)). Conclusions—Our present study proves that conducting dynamic liver scintigraphies with [^99mTc]Tc-mebrofenin has potential value in staging liver fibrosis. The benefits of this method, including whole liver imaging and direct imaging of the liver function, provide an advantage over presently used quantitative imaging modalities.

Accuracy of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) for assessing steatosis and fibrosis in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, and among the non-invasive tests, controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) have shown better diagnostic performance in NAFLD. This meta-analysis aimed to evaluate the performance of CAP and LSM for assessing steatosis and fibrosis in NAFLD.

METHODS

We searched the PubMed, Web of Science, Cochrane Library, and Embase databases for relevant articles published up to February 13^th, 2022, and selected studies that met the inclusion and exclusion criteria, and evaluated the quality of evidence. Then we pooled sensitivity (SE), specificity (SP), and area under receiver operating characteristic (AUROC) curves. A random effect model was applied regardless of heterogeneity. Meta-regression analysis and subgroup analysis were performed to explore heterogeneity, and Fagan plot analysis was used to evaluate clinical utility. This meta-analysis was completed in Nanjing, Jiangsu and registered on PROSPERO (CRD42022309965).

FINDINGS

A total of 10537 patients from 61 studies were included in our meta-analysis. The AUROC of CAP were 0·924, 0·794 and 0·778 for steatosis grades ≥ S1, ≥ S2 and = S3, respectively, and the AUROC of LSM for detecting fibrosis stages ≥ F1, ≥ F2, ≥ F3, and = F4 were 0·851, 0·830, 0·897 and 0·925, respectively. Subgroup analysis revealed that BMI ≥ 30 kg/m² had lower accuracy for diagnosing S ≥ S1, ≥ S2 than BMI<30 kg/m². For the mean cut-off values, significant differences were found in CAP values among different body mass index (BMI) populations and LSM values among different regions. For diagnosing S ≥ S1, ≥ S2 and = S3, the mean CAP cut-off values for BMI ≥ 30 kg/m² were 30·7, 28·2, and 27·9 dB/m higher than for BMI < 30 kg/m² (P = 0·001, 0·001 and 0·018, respectively). For diagnosing F ≥ F2 and = F4, the mean cut-off values of Europe and America were 0·96 and 2·03 kPa higher than Asia (P = 0·027, P = 0·034), respectively. In addition, the results did not change significantly after sensitivity analysis and the trim and fill method to correct for publication bias, proving that the conclusions are robust.

INTERPRETATION

The good performance of CAP and LSM for the diagnosis of mild steatosis (S ≥ S1), advanced liver fibrosis (F ≥ F3), and cirrhosis (F = F4) can be used to screen for NAFLD in high-risk populations. Of note, the accuracy of CAP for the detection of steatosis in patients with obesity is reduced and requires specific diagnostic values. For LSM, the same diagnostic values can be used when the appropriate probes are selected based on BMI and the automated probe selection tool. The performance of CAP and LSM in assessing steatosis in patients with obesity, moderate to severe steatosis, and low-grade fibrosis should be further validated and improved in the future.

FUNDING

The study was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Evaluation of nonalcoholic fatty liver disease (NAFLD) in severe obesity using noninvasive tests and imaging techniques

The prevalence of nonalcoholic fatty liver disease (NAFLD) and the more severe and inflammatory type, nonalcoholic steatohepatitis (NASH), is increasing rapidly. Especially in high-risk patients, that is those with obesity, metabolic syndrome, and type 2 diabetes mellitus, the prevalence of NAFLD can be as high as 80% while NASH may be present in 20% of these subjects. With the worldwide increase of obesity, it is most likely that these numbers will rise. Since advanced stages of NAFLD and NASH are strongly associated with morbidity and mortality-in particular, cardiovascular disease, liver cirrhosis, and hepatocellular carcinoma-it is of great importance to identify subjects at risk. A great variety of noninvasive tests has been published to diagnose NAFLD and NASH, especially using blood- and imaging-based tests. Liver biopsy remains the gold standard for NAFLD/NASH. This review aims to summarize the different mechanisms leading to NASH and liver fibrosis, the different noninvasive liver tests to diagnose and evaluate patients with severe obesity.

Shear-Wave Elastography Using Commercially Available Ultrasound in a Mouse Model of Chronic Liver Disease

Elastography is currently used clinically to diagnose the degree of liver stiffness. We sought to develop a shear-wave elastography (SWE) measurement method using ultrasound in mice and to compare its results with those of other noninvasive tests for liver fibrosis. We divided male mice into three groups (normal (G1), liver fibrosis (G2), and fatty liver (G3)). We measured mouse liver SWE values and compared them with T1rho and T2 values from magnetic resonance imaging results. We also compared the SWE values with the expression levels of a serum liver fibrosis biomarker (Mac-2-binding protein (M2BP)) and hepatic genes. SWE values significantly increased over time in G2 but did not change in G3. T1rho values in G2 and G3 were significantly increased compared with those in G1. T2 values in G2 did not increase compared with those in group 1. T2 values in G3 significantly increased compared with those in groups 1 and 2. In G2, SWE values significantly and positively correlated with T1rho values. SWE values significantly correlated with serum M2BP levels in G2 but did not correlate with inflammatory gene expression. We could measure SWE values to assess the degree of liver fibrosis in mouse models of liver disease.

Fibrosis regression following hepatitis C antiviral therapy

Hepatitis C virus (HCV) infection is one of the most common causes of liver pathology. It is a major etiological factor of continuous liver injury by triggering an uncontrolled inflammatory response, causing liver fibrosis and cirrhosis. Liver fibrosis is a dynamic process that can be reversible upon timely cessation of the injurious agent, which in cases of HCV is represented by the sustained virological response (SVR) following antiviral therapies. Direct-acting antiviral therapy has recently revolutionized HCV therapy and minimized complications. Liver fibrosis can be assessed with variable invasive and non-invasive methods, with certain limitations. Despite the broad validation of the diagnostic and prognostic value of non-invasive modalities of assessment of liver fibrosis in patients with HCV, the proper interpretation of liver stiffness measurement in patients after SVR remains unclear. It is also still a debate whether this regression is caused by the resolution of liver injury following treatment of HCV, rather than true fibrosis regression. Regression of liver fibrosis can possess a positive impact on patient's quality of life reducing the incidence of complications. However, fibrosis regression does not abolish the risk of developing hepatocellular carcinoma, which mandates regular screening of patients with advanced fibrosis.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the past years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato, the Società Italiana di Diabetologia and the Società Italiana dell'Obesità reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure and Istituto Superiore di Sanità. Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources.Level of evidence Level of evidence of recommendations for each PICO question were reported according to available evidence.

Relationship between Liver Stiffness and Steatosis in Obesity Conditions: In Vivo and In Vitro Studies

Obesity is a major risk factor for metabolic dysfunction such as non-alcoholic fatty liver disease (NAFLD). The NAFLD spectrum ranges from simple steatosis, to steatohepatitis, fibrosis, and cirrhosis. The aim of this study is to characterize the grade of steatosis being associated with overnutrition and obesity, both at the level of single hepatocyte and whole liver, and to correlate it with the hepatocyte/liver stiffness and dysfunction. For the in vivo study, 60 subjects were enrolled and grouped based on the stage of liver steatosis/fibrosis according to biochemical analyses, liver ultrasonography (USG) and acoustic radiation force impulse shear wave elastography (ARFI-SWE). For single hepatocyte analyses we employed in vitro models of moderate and severe steatosis on which to assess the single cell biomechanics by Single Cell Force Spectroscopy (SCFS) and Quantitative Phase Microscopy (QPM). Results show that in vivo liver stiffness depends mainly on the extent of fat accumulation and not on fibrosis. These results parallel the in vitro observations showing that hepatocyte stiffness and dysfunction increase with increasing fat accumulation and lipid droplet enlargement. Our findings indicate that the extent of steatosis markedly affects the biomechanical properties of both liver and single hepatocytes thus proving insights about the role of modulation of liver/hepatocyte elasticity as a physical mechanism transducing the obesity-dependent excess of plasmatic lipids towards liver steatosis and dysfunction.

Real-Life Early Anthropometric, Lipid and Liver Changes after Direct-Acting Antiviral Therapy in PLWHIV with HCV Co-Infection

Treatment with interferon-free direct-acting antivirals (DAA) has become the gold standard in chronic hepatitis C virus (HCV) infection. Nevertheless, little research about the metabolic impact of achieving sustained virological response (SVR) is available in HCV/HIV co-infected patients. This research aimed to evaluate early anthropometric, lipid and liver parameters changes after achieving SVR 12 weeks after treatment (SVR12). A real-life retrospective descriptive before-after study assessed 128 DAA treatment episodes from 2015 to 2019 in HCV/HIV co-infected patients. Anthropometric parameters (weight, body mass index), lipid profile, genotype (GT) and viral load, liver data (basics laboratory necroinflammatory parameters and transient elastography (TE)) were collected before treatment with DAA (baseline), and when SVR12 was achieved. Significant increases (p < 0.01) were found in the early lipid profile, measured by LDLc (84.6 ± 35.0 vs. 108.6 ± 35.1 mg/dL) and total cholesterol (161.3 ± 41.0 vs. 183.3 ± 41.6 mg/dL). Significant changes (p < 0.05) were found in liver parameters, measured by ALT (58.2 ± 34.0 vs. 22.0 ± 16.0 U/L), bilirubin (0.8 ± 0.6 vs. 0.6 ± 0.5 mg/dL), albumin (4.2 ± 0.4 vs. 4.3 ± 0.3 g/dL) and liver stiffness (LS) (13.7 ± 13.3 vs. 11.8 ± 12.1 kPa). The main conclusions were that the use of DAA has an early negative impact on lipid metabolism. Achieving SVR12 against HCV leads to an early improvement in liver function and LS in HCV/HIV co-infected patients without interference with antiretroviral treatment (ART) and DAA. Short-term close lipid monitoring may be necessary when combining protease inhibitors. HCV-GT-3/HIV co-infected patients might require further close monitoring for residual fibrosis. These findings can be relevant for actual clinical practice.

Diagnostic accuracy of non-invasive tests for advanced fibrosis in patients with NAFLD: an individual patient data meta-analysis

OBJECTIVE

Liver biopsy is still needed for fibrosis staging in many patients with non-alcoholic fatty liver disease. The aims of this study were to evaluate the individual diagnostic performance of liver stiffness measurement by vibration controlled transient elastography (LSM-VCTE), Fibrosis-4 Index (FIB-4) and NAFLD (non-alcoholic fatty liver disease) Fibrosis Score (NFS) and to derive diagnostic strategies that could reduce the need for liver biopsies.

DESIGN

Individual patient data meta-analysis of studies evaluating LSM-VCTE against liver histology was conducted. FIB-4 and NFS were computed where possible. Sensitivity, specificity and area under the receiver operating curve (AUROC) were calculated. Biomarkers were assessed individually and in sequential combinations.

RESULTS

Data were included from 37 primary studies (n=5735; 45% women; median age: 54 years; median body mass index: 30 kg/m²; 33% had type 2 diabetes; 30% had advanced fibrosis). AUROCs of individual LSM-VCTE, FIB-4 and NFS for advanced fibrosis were 0.85, 0.76 and 0.73. Sequential combination of FIB-4 cut-offs (<1.3; ≥2.67) followed by LSM-VCTE cut-offs (<8.0; ≥10.0 kPa) to rule-in or rule-out advanced fibrosis had sensitivity and specificity (95% CI) of 66% (63-68) and 86% (84-87) with 33% needing a biopsy to establish a final diagnosis. FIB-4 cut-offs (<1.3; ≥3.48) followed by LSM cut-offs (<8.0; ≥20.0 kPa) to rule out advanced fibrosis or rule in cirrhosis had a sensitivity of 38% (37-39) and specificity of 90% (89-91) with 19% needing biopsy.

CONCLUSION

Sequential combinations of markers with a lower cut-off to rule-out advanced fibrosis and a higher cut-off to rule-in cirrhosis can reduce the need for liver biopsies.

Paediatric non-alcoholic fatty liver disease: an approach to pathological evaluation

Non-alcoholic fatty liver disease (NAFLD) is becoming an increasingly important healthcare issue along with the rising rates of obesity worldwide. It is the most common chronic liver disease in the paediatric population and the fastest growing indication for liver transplant in young adults. The pathogenesis is complex with contributions from multiple factors and genetic predisposition. While non-invasive laboratory tests and imaging modalities are being increasingly used, the liver biopsy continues to play a crucial role in the diagnosis and prognosis of NAFLD. Histologically, the assessment of paediatric fatty liver disease requires special considerations with respect to a periportal predominant pattern seen in prepubertal patients, as well as a different set of disease processes in the differential diagnosis. In this review, we provide a summary of current knowledge on the epidemiology, pathogenesis and clinical course of paediatric NAFLD as well as the clinical guidelines on diagnosis and management. We discuss the indications and limitations of liver biopsy, histological patterns seen in paediatric NAFLD, other entities to be considered in the differential diagnosis, and conclude with appropriate triaging of liver biopsies and essential elements of pathology reporting.

A sequential approach using the age-adjusted fibrosis-4 index and vibration-controlled transient elastography to detect advanced fibrosis in Korean patients with non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Vibration-controlled transient elastography (VCTE) has shown good diagnostic performance in predicting fibrosis stages in patients with non-alcoholic fatty liver disease (NAFLD). However, an optimal diagnostic approach to detect advanced fibrosis in patients with NAFLD has not been established.

APPROACH AND RESULTS

We prospectively collected data from 539 subjects who underwent liver biopsy at a single centre between January 2014 and December 2019. Diagnostic performance was estimated using the area under the receiver-operating characteristic curve (AUROC). Several models combining the fibrosis 4 index (FIB-4) score and liver stiffness measurement (LSM) were analysed to reduce the need for unnecessary liver biopsies. We observed significant fibrosis (≥F2), advanced fibrosis (≥F3) and cirrhosis (F4) in 173 (32.1%), 74 (13.7%) and 46 subjects (8.5%), respectively. The AUROCs (95% CI) for LSMs to diagnose ≥F2, ≥F3 and F4 were 0.82 (0.78-0.85), 0.92 (0.89-0.94) and 0.95 (0.93-0.97), respectively. Optimal LSM cut-off values were 6.7 (≥F2), 8.3 (≥F3) and 9.8 (F4) kPa. LSMs were affected by waist circumference, serum albumin and fibrosis stage (R²  = 0.315). Abdominal obesity, elevated transaminase, diabetes mellitus and high IQR/Median were associated with the discordance of ≥2 fibrosis stages between LSMs and histologic data. The sequential use of the age-adjusted FIB-4 and LSMs yielded the least uncertainty (5.3%) in classifying disease severity with the highest diagnostic accuracy (81%) among a variety of non-invasive test combinations.

CONCLUSIONS

The sequential approach of age-adjusted FIB-4 and VCTE could represent a practical diagnostic strategy to detect advanced fibrosis in NAFLD (ClinicalTrials.gov #NCT02206841).

Effect of liver steatosis on liver stiffness measurement in chronic hepatitis B patients with normal serum alanine aminotransferase levels: A multicentre cohort study

Liver steatosis is becoming increasingly common in patients with chronic hepatitis B (CHB), and its effect on liver stiffness measurement (LSM), as assessed by transient elastography, remains controversial. Seven hundred and fifty-five patients with CHB and normal serum alanine aminotransferase levels, who underwent vibration-controlled transient elastography and liver biopsy, were included in the study. We examined whether the histological degree of liver steatosis affects the accuracy of transient elastography-assessed LSM in these patients. Among the 755 CHB patients included in the study, 286 (37.9%) had liver steatosis, of whom 156 had grade S1, 74 had grade S2, and 56 had grade S3 on histology. Presence of liver steatosis was independently associated with greater body mass index (BMI, adjusted-odds ratio [OR] = 5.786, 95% CI: 3.998-8.373, p = 0.018), and higher serum total cholesterol (adjusted-OR = 7.944, 95% CI: 4.731-13.339, p < 0.001) and triglyceride levels (adjusted-OR = 2.777, 95% CI: 2.050-3.761, p < 0.001). There was no significant association between liver steatosis and fibrosis stage (OR = 1.016, 95% CI: 0.905-1.140, p = 0.790). Age (B-coefficient = 0.020, 95% CI: 0.001-0.040, p = 0.044), BMI (B-coefficient = 0.060, 95% CI: 0.011-0.127, p = 0.019), serum gamma-glutamyl-transpeptidase (GGT, B-coefficient = 0.015, 95% CI: 0.001-0.029, p = 0.032), positivity for HBeAg (B-coefficient = -0.816, 95% CI: -1.568 to -0.064, p = 0.034), as well as liver fibrosis stage (B-coefficient = 2.796, 95% CI: 2.501-3.090, p < 0.001), and inflammation activity grade (B-coefficient = 0.648, 95% CI: 0.162-1.135, p = 0.009) were all independently associated with higher LSM, while no significant association was found between degree of liver steatosis and LSM. Among patients with the same histological fibrosis stage, LSM values did not show any significant difference among patients with absent, mild, moderate or severe steatosis. We conclude that liver steatosis has no significant effect on transient elastography-measured LSM in CHB patients with normal serum alanine aminotransferase levels.

Dual-Energy Computed Tomography in Diffuse Liver Diseases

Dual-energy computed tomography (DECT) is an advancement in the field of CT, where images are acquired at two energies. Materials are identified and quantified based on their attenuation pattern at two different energy beams using various material decomposition algorithms. With its ability to identify and quantify materials such as fat, calcium, iron, and iodine, DECT adds great value to conventional CT and has innumerable applications in body imaging. Continuous technological advances in CT scanner hardware, material decomposition algorithms, and image reconstruction software have led to considerable growth of these applications. Among all organs, the liver is the most widely investigated by DECT, and DECT has shown promising results in most liver applications. In this article, we aim to provide an overview of the role of DECT in the assessment of diffuse liver diseases, mainly the deposition of fat, fibrosis, and iron and review the most relevant literature.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes, and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the last years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato (AISF), the Società Italiana di Diabetologia (SID) and the Società Italiana dell'Obesità (SIO) reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure (CNEC) and Istituto Superiore di Sanità (ISS). Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources. Level of evidence: Level of evidence of recommendations for each PICO question were reported according to available evidence.

Quality criteria for the measurement of liver stiffness

Liver elastography offers the possibility of a quick, non-invasive, and painless evaluation of the liver with immediate results at bedside. Transient elastography is the most validated technology, and many others such as point shear wave elastography, 2D-shear wave elastography, or magnetic resonance elastography have been developed. To ensure the best evaluation, several conditions of examination must be respected for liver stiffness measurement. Indeed, patient, operator and examination characteristics have all been shown to influence the result of liver stiffness measurement. Food intake increases liver stiffness, whereas withdrawal in alcoholics is associated with a decrease in elastography results. Inter-observer reproducibility of the measurement seems suboptimal, and the influence of the operator experience is still being debated. The measurement site and the FibroScan® probe must be correctly chosen. Finally, the intrinsic characteristics and quality criteria of the measurement, especially the interquartile range/median ratio, must be carefully checked to avoid overestimation of liver stiffness. Most of the results come from studies which have evaluated transient elastography, with less data available for the other technologies. Liver stiffness measurement could appear as a simple way to explore the liver, but several conditions must be met before deciding the patient management according to its result.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes, and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the last years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato (AISF), the Società Italiana di Diabetologia (SID) and the Società Italiana dell'Obesità (SIO) reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure (CNEC) and Istituto Superiore di Sanità (ISS). Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources. Level of evidence: Level of evidence of recommendations for each PICO question were reported according to available evidence.

Inflammatory activity affects the accuracy of liver stiffness measurement by transient elastography but not by two-dimensional shear wave elastography in non-alcoholic fatty liver disease

BACKGROUND

In patients with non-alcoholic fatty liver disease (NAFLD), the impact of the severity of steatosis and inflammatory activity on the accuracy of liver stiffness measurement (LSM) by transient elastography (TE) and by two-dimensional shear wave elastography (2D-SWE) in staging liver fibrosis is still debated and scarce. We aimed to focus on this aspect.

METHODS

We prospectively studied 104 patients requiring biopsy for the assessment of NAFLD. We used ordinary least squares regression to test for differences in the association between fibrosis and LSM by TE and 2D-SWE when other factors (steatosis and inflammatory activity) are considered.

RESULTS

Among 104 patients, 102 had reliable LSM by TE, and 88 had valid LSM by 2D-SWE. The association between fibrosis based on histology and LSM was significantly stronger when 2D-SWE assessed LSM compared to TE (Spearman's correlation coefficient of .71; P < .001 vs .51, P < .001; Z = 2.21, P = .027). Inflammatory activity was an independent predictor of LSM by TE but not of LSM by 2D-SWE. After controlling for fibrosis, age, sex and body mass index, the inflammatory activity and the interaction between inflammatory activity and fibrosis independently explained 11% and 13% of variance in LSM by TE respectively. Steatosis did not affect the association of fibrosis and LSM by either method.

CONCLUSION

Inflammatory activity on histology significantly affects LSM by TE, but not LSM by 2D-SWE in NAFLD. LSM by 2D-SWE reflects liver fibrosis more accurately than LSM by TE. Furthermore, the severity of steatosis on histology did not influence the association of LSM and fibrosis by either elastography method.

Brazilian Society of Hepatology and Brazilian College of Radiology practice guidance for the use of elastography in liver diseases

In 2015 the European Association for the Study of Liver Diseases (EASL) and the Asociación Latinoamericana para el Estudio del Hígado (ALEH) published a guideline for the use of non-invasive markers of liver disease. At that time, this guideline focused on the available data regarding ultrasonic-related elastography methods. Since then, much has been published, including new data about XL probe use in transient elastography, magnetic resonance elastography, and non-invasive liver steatosis evaluation. In order to draw evidence-based guidance concerning the use of elastography for non-invasive assessment of fibrosis and steatosis in different chronic liver diseases, the Brazilian Society of Hepatology (SBH) and the Brazilian College of Radiology (CBR) sponsored a single-topic meeting on October 4th, 2019, at São Paulo, Brazil. The aim was to establish specific recommendations regarding the use of imaging-related non-invasive technology to diagnose liver fibrosis and steatosis based on the discussion of evidence-based topics by an organizing committee of experts. It was submitted online to all SBH and CBR members. The present document is the final version of the manuscript that supports the use of this new technology as an alternative to liver biopsy.