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

High Diagnostic Value of Transient Elastography for Advanced Fibrosis and Cirrhosis in Patients With Chronic Hepatitis Delta

BACKGROUND & AIMS

Liver biopsy remains the gold standard for fibrosis staging in patients with chronic hepatitis delta (CHD). Here, we comparatively evaluated the performance of transient elastography (TE) and biomarkers for the diagnosis of liver fibrosis in patients with CHD.

METHODS

A total of 230 HDV-infected RNA-positive patients from various centers who underwent liver biopsy and liver stiffness measurements (LSMs) using Fibroscan, within a period of 6 months maximum, were investigated retrospectively. Area under the receiver operating characteristic curve and Youden index were used to establish cutoff values of LSM. TE was compared with other noninvasive tests: aspartate aminotransferase to platelet ratio index, Fibrosis-4, and Delta-4 fibrosis scores.

RESULTS

Histologic fibrosis stage distribution was: 20.4% for F0-F1; 27.0% for F2; 18.7% for F3; and 33.9% for F4. TE demonstrated good diagnostic performance for detecting cirrhosis and advanced fibrosis with an Area under the receiver operating characteristic curve of 0.88 and 0.86, which were significantly higher than those obtained with the other noninvasive tests (P = .004 and P < .001). With a cutoff value of >12 kPa for cirrhosis, the sensitivity was 70.5%, specificity was 86.2%, positive predictive value was 72.4%, negative predictive value was 85.1%, and accuracy was 80.9%. Using 10.4 kPa as the cutoff value for F3, the sensitivity was 70.2%, specificity was 83.5%, positive predictive value was 82.5%, negative predictive value was 71.7%, and accuracy was 76.5%. In 89% of patients with LSM ≤6.2 kPa, liver biopsy disclosed only absent or minimal fibrosis.

CONCLUSION

TE demonstrated good diagnostic performance for advanced fibrosis and cirrhosis in patients with CHD. Advanced fibrosis is highly probable for LSM values ≥10 kPa. LSM values <6 kPa almost totally exclude significant fibrosis. Between 6 and 10 kPa, liver biopsy should be discussed.

Modern ultrasound techniques for diagnosing liver steatosis and fibrosis: A systematic review with a focus on biopsy comparison

BACKGROUND

This review evaluated the diagnostic effectiveness of various ultrasound (US) methods compared to liver biopsy.

AIM

To determine the diagnostic accuracy of US techniques in assessing liver fibrosis and steatosis in adults, using the area under the receiver operating characteristic curve (AUROC) as the standard measure.

METHODS

The review included original retrospective or prospective studies published in the last three years in peer-reviewed medical journals, that reported AUROC values. Studies were identified through PubMed searches on January 3 and April 30, 2024. Quality was assessed using the QUADAS-2 tool. Results were tabulated according to the diagnostic method and the type of liver pathology.

RESULTS

The review included 52 studies. For liver fibrosis detection, 2D-shear wave elastography (SWE) AUROCs ranged from 0.54 to 0.994, showing better accuracy for advanced stages. Modifications, including 2D-SWE with propagation map guidance and supersonic imagine achieved AUROCs of 0.84 to nearly 1.0. point SWE and classical SWE had AUROCs of 0.741-0.99, and 0.507-0.995, respectively. Transient elastography (TE), visual TE, vibration-controlled TE (VCTE), and FibroTouch reported AUROCs close to 1.0. For steatosis, VCTE with controlled attenuation parameter showed AUROCs up to 0.89 (for ≥ S1), acoustic radiation force impulse ranged from 0.762 to 0.784, US attenuation parameter from 0.88 to 0.93, and normalized local variance measurement from 0.583 to 0.875. Most studies had a low risk of bias across all or most domains, but evidence was limited by variability in study quality and small sample sizes. Innovative SWE variants were evaluated in a single study.

CONCLUSION

Modern US techniques can serve as effective noninvasive diagnostic tools for liver fibrosis and steatosis, with the potential to reduce the reliance on biopsies.

Role of noninvasive tests in the prognostication of metabolic dysfunction-associated steatotic liver disease

In managing metabolic dysfunction-associated steatotic liver disease, which affects over 30% of the general population, effective noninvasive biomarkers for assessing disease severity, monitoring disease progression, predicting the development of liver-related complications, and assessing treatment response are crucial. The advantage of simple fibrosis scores lies in their widespread accessibility through routinely performed blood tests and extensive validation in different clinical settings. They have shown reasonable accuracy in diagnosing advanced fibrosis and good performance in excluding the majority of patients with a low risk of liver-related complications. Among patients with elevated serum fibrosis scores, a more specific fibrosis and imaging biomarker has proved useful to accurately identify patients at risk of liver-related complications. Among specific fibrosis blood biomarkers, enhanced liver fibrosis is the most widely utilized and has been approved in the United States as a prognostic biomarker. For imaging biomarkers, the availability of vibration-controlled transient elastography has been largely improved over the past years, enabling the use of liver stiffness measurement (LSM) for accurate assessment of significant and advanced fibrosis, and cirrhosis. Combining LSM with other routinely available blood tests enhances the ability to diagnose at-risk metabolic dysfunction-associated steatohepatitis and predict liver-related complications, some reaching an accuracy comparable to that of liver biopsy. Magnetic resonance imaging-based modalities provide the most accurate quantification of liver fibrosis, though the current utilization is limited to research settings. Expanding their future use in clinical practice depends on factors such as cost and facility availability.

Comparison of the diagnostic accuracy of shear wave elastography with transient elastography in adult nonalcoholic fatty liver disease: a systematic review and network meta-analysis of diagnostic test accuracy

PURPOSE

To compare the diagnostic test accuracy (DTA) of shear wave elastography (SWE) to that of transient elastography (TE) for liver fibrosis grade assessment in nonalcoholic fatty liver disease adults.

METHODS

MEDLINE, The Cochrane Library, and Web of Science were searched. Inclusion criteria were primary studies examining DTA of TE, point SWE (pSWE), two-dimensional SWE (2D-SWE), or magnetic resonance elastography (MRE) with liver biopsy. Network meta-analysis was conducted using a Bayesian bivariate mixed-effects model.

RESULTS

For fibrosis grade 2 or higher, 15 studies with 25 observations (16 observations for TE, 1 for MRE, 4 for pSWE and 2D-SWE; 2,066 patients) were included; the pooled sensitivity and specificity were 0.79 (95% credible interval (CrI) 0.70-0.86; 95% prediction interval (PI) 0.36-0.96) and 0.73 (95% CrI 0.62-0.82; 95% PI 0.23-0.96) for TE, 0.68 (95% CrI 0.48-0.83; 95% PI 0.23-0.94) and 0.75 (95% CrI 0.53-0.88; 95% PI 0.24-0.97) for pSWE, 0.85 (95% CrI 0.70-0.93; 95% PI 0.40-0.98) and 0.72 (95% CrI 0.49-0.86; 95% PI 0.20-0.96) for 2D-SWE, respectively. The proportion of studies classified as unclear in QUADAS-2 was high, and the results were heterogeneous.

CONCLUSION

2D-SWE could be recommended as TE is for liver fibrosis assessment. The protocol of this systematic review and network meta-analysis has been registered in PROSPERO (CRD42022327249). All included primary papers have already been published and the information and data can be used freely.

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.

Diagnostic accuracy of 2D-SWE ultrasound for liver fibrosis assessment in MASLD: A multilevel random effects model meta-analysis

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) imposes significant health care burdens. Early detection of advanced fibrosis and cirrhosis in MASLD is essential due to their unfavorable outcomes. This multilevel random-effects meta-analysis aimed to provide the best evidence for the diagnostic accuracy of 2-dimensional shear wave elastography in detecting liver fibrosis in biopsy-proven MASLD.

APPROACH AND RESULTS

This study involves systematic search in PubMed/MEDLINE, Embase, Scopus, Web of Science, LILACS, and Cochrane Library electronic databases for full-text articles published in any language up to February 26, 2024. Included studies reported liver stiffness measurement by 2-dimensional shear wave elastography and used histological diagnosis as the gold standard. A linear mixed-effects multiple thresholds model was employed, and summary estimates for sensitivity, specificity (Sp), and summary area under the receiver operator characteristic curve were computed. Twenty observational studies (SuperSonic Imagine, General Electric Healthcare, and Canon Medical Systems) fulfilled the inclusion criteria, comprising 2223 participants with biopsy-proven MASLD. The prevalence of mild fibrosis (F1), significant fibrosis (F2), advanced fibrosis (F3), and cirrhosis (F4) was 30.0%, 18.5%, 17.9%, and 10.9%, respectively. The summary area under the receiver operator characteristic curve [95% CI] in detecting ≥F1, ≥F2, ≥F3, and F4 for all ultrasound machines considered together were 0.82 [0.16-0.98], 0.82 [0.76-0.88], 0.86 [0.77-0.93], and 0.89 [0.80-0.95], respectively. The optimal cutoff values were 6.432 kPa for ≥F1, 8.174 kPa for ≥F2, 9.418 kPa for ≥F3, and 11.548 kPa for F4, respectively.

CONCLUSIONS

Our meta-analysis identified optimized cutoffs for fibrosis staging by 2-dimensional shear wave elastography in etiology-specific chronic liver diseases (MASLD), with excellent diagnostic performance, underscoring the potential for standardizing cutoff values.

Enhanced Ferritin‐Manganese Interaction by Nanoplatinum Growth Enabling Liver Fibrosis 3D Magnetic Resonance Visualization and Synergistic Therapy with Real‐Time Monitoring

Early detection and timely intervention are essential to prevent liver fibrosis from progressing to cirrhosis or hepatocellular carcinoma. Herein, utilizing the enhanced ferritin‐manganese interaction by nanoplatinum growth, a novel ferritin‐platinum‐manganese magnetic resonance nanoplatform with RGD grafting and metformin loading (FNMMR) is developed. RGD can enhance the targeting ability of the nanoplatform toward integrin αVβ3 on activated hepatic stellate cells (aHSCs) in liver fibrosis. Systemic delivery of FNMMR shows clear degree‐dependent magnetic resonance contrast enhancement in liver fibrosis. 3D reconstruction techniques and histogram‐based features are achieved to qualitatively and quantitatively analyze the inhomogeneous liver fibrosis areas. FNMMR with catalase‐like activity can catalyze the generation of O2 to alleviate the liver fibrosis hypoxia and inhibit the expression of HIF‐1α, blocking the TGF‐β1/Smad signaling pathway. In addition, metformin shows synergy with HIF‐1α reduction in blocking the TGF‐β1/Smad pathway, effectively inhibiting the activation of HSCs and reducing collagen formation. Furthermore, FNMMR can achieve real‐time anti‐fibrotic therapy monitoring by magnetic resonance imaging. Importantly, no obvious side effects can be observed in both histological and hematology examinations. Therefore, this work presents a novel nanoplatform for accurate liver fibrosis diagnosis and synergistic anti‐fibrotic therapy with real‐time monitoring.

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.

Optimal cut-offs of vibration-controlled transient elastography and magnetic resonance elastography in diagnosing advanced liver fibrosis in patients with nonalcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND/AIMS

Opinions differ regarding vibration-controlled transient elastography and magnetic resonance elastography (VCTE/MRE) cut-offs for diagnosing advanced fibrosis (AF) in patients with non-alcoholic fatty liver disease (NAFLD). We investigated the diagnostic performance and optimal cut-off values of VCTE and MRE for diagnosing AF.

METHODS

Literature databases, including Medline, EMBASE, Cochrane Library, and KoreaMed, were used to identify relevant studies published up to June 13, 2023. We selected studies evaluating VCTE and MRE regarding the degree of liver fibrosis using liver biopsy as the reference. The sensitivity, specificity, and area under receiver operating characteristics curves (AUCs) of the pooled data for VCTE and MRE for each fibrosis stage and optimal cut-offs for AF were investigated.

RESULTS

A total of 19,199 patients from 63 studies using VCTE showed diagnostic AUC of 0.83 (95% confidence interval: 0.80-0.86), 0.83 (0.80-0.86), 0.87 (0.84-0.90), and 0.94 (0.91-0.96) for ≥F1, ≥F2, ≥F3, and F4 stages, respectively. Similarly, 1,484 patients from 14 studies using MRE showed diagnostic AUC of 0.89 (0.86-0.92), 0.92 (0.89-0.94), 0.89 (0.86-0.92), and 0.94 (0.91-0.96) for ≥F1, ≥F2, ≥F3, and F4 stages, respectively. The diagnostic AUC for AF using VCTE was highest at 0.90 with a cut-off of 7.1-7.9 kPa, and that of MRE was highest at 0.94 with a cut-off of 3.62-3.8 kPa.

CONCLUSION

VCTE (7.1-7.9 kPa) and MRE (3.62-3.8 kPa) with the suggested cut-offs showed favorable accuracy for diagnosing AF in patients with NAFLD. This result will serve as a basis for clinical guidelines for non-invasive tests and differential diagnosis of AF.

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.

Advancements of non‐invasive imaging technologies for the diagnosis and staging of liver fibrosis: Present and future

Liver fibrosis is a reparative response triggered by liver injury. Non‐invasive assessment and staging of liver fibrosis in patients with chronic liver disease are of paramount importance, as treatment strategies and prognoses depend significantly on the degree of fibrosis. Although liver fibrosis has traditionally been staged through invasive liver biopsy, this method is prone to sampling errors, particularly when biopsy sizes are inadequate. Consequently, there is an urgent clinical need for an alternative to biopsy, one that ensures precise, sensitive, and non‐invasive diagnosis and staging of liver fibrosis. Non‐invasive imaging assessments have assumed a pivotal role in clinical practice, enjoying growing popularity and acceptance due to their potential for diagnosing, staging, and monitoring liver fibrosis. In this comprehensive review, we first delved into the current landscape of non‐invasive imaging technologies, assessing their accuracy and the transformative impact they have had on the diagnosis and management of liver fibrosis in both clinical practice and animal models. Additionally, we provided an in‐depth exploration of recent advancements in ultrasound imaging, computed tomography imaging, magnetic resonance imaging, nuclear medicine imaging, radiomics, and artificial intelligence within the field of liver fibrosis research. We summarized the key concepts, advantages, limitations, and diagnostic performance of each technique. Finally, we discussed the challenges associated with clinical implementation and offer our perspective on advancing the field, hoping to provide alternative directions for the future research.

Possible use of 2D shear wave liver elastography in new-onset ascites evaluation

BACKGROUND

No data on the use of 2D shear wave elastography exists regarding the evaluation of the new-onset ascites causality.

AIMS

To determine whether 2D shear wave elastography can help in the non-invasive assessment of the new-onset ascites cause. To assess the applicability of liver stiffness measured by 2D shear wave elastography using Esaote MyLab Nine apparatus in patients with ascites.

METHODS

In 52 consecutive patients with new-onset ascites (January 2020 to October 2021), liver stiffness using 2D shear wave elastography was prospectively measured. The reliable measurements were used for further analysis. Relevant clinical and laboratory data was collected.

RESULTS

The calculated liver stiffness measurement cut-off value of 14.4 kPa held 94% accuracy, 100% sensitivity, and 83% specificity when determining ascites with serum ascites albumin gradient ≥11 g/L. Reliable 2D shear wave elastography success rate was 84%.

CONCLUSIONS

2D shear wave elastography may potentially be used to differentiate transudative from exudative ascites, especially in patients with portal hypertension and peritoneal carcinomatosis.

Effect of Intermittent Fasting on Lipid Profile, Anthropometric and Hepatic Markers in Non-Alcoholic Fatty Liver Disease (NAFLD): A Systematic Review

BACKGROUND

The first-line treatment for non-alcoholic fatty liver disease (NAFLD) is lifestyle modification; this should accompany any pharmacological intervention. Intermittent fasting (IF) has shown benefits over metabolic and cardiovascular parameters. Non-religious IF includes Time-Restricted Feeding (TRF), Alternate-Day Fasting (ADF), and 5:2 IF interventions.

OBJECTIVE

To evaluate the effects of IF on anthropometric, liver damage, and lipid profile markers in subjects with NAFLD.

METHODS

A bibliographic search was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using PubMed and Scopus databases.

RESULTS

Five studies involving 470 patients with NAFLD were included. In relation to anthropometric markers, all the articles reported body weight reduction (2.48-7.63%), but only ADF and 5:2 IF reported a body weight reduction >5%; also, all the articles reported fat mass reduction. Concerning hepatic markers, all the articles reported a reduction in hepatic steatosis and alanine aminotransferase activity, but no changes in fat-free mass and high-density lipoprotein cholesterol levels. There were variable results on fibrosis, other liver enzymes, waist circumference and body mass index, as well as the levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol.

CONCLUSION

Any form of IF could be potentially beneficial for NAFLD treatment and some associated cardiometabolic parameters. However, it is necessary to evaluate the effects and safety of IF in long-term studies involving a higher number of participants with different stages of NAFLD. The effect of IF on NAFLD-associated vascular risk also needs evaluation.

Non-Invasive Measurement of Hepatic Fibrosis by Transient Elastography: A Narrative Review

Transient elastography by FibroScan® (Echosens, Paris, France) is a non-invasive method that can provide a reliable measurement of liver fibrosis through the evaluation of liver stiffness. Despite its limitations and risks, liver biopsy has thus far been the only procedure able to provide data to quantify fibrosis. Scientific evidence and clinical practice have made it possible to use FibroScan® in the diagnostic work-up of several liver diseases to monitor patients' long-term treatment response and for complication prevention. For these reasons, this procedure is widely used in clinical practice and is still being investigated for further applications. The aim of this narrative review is to provide a comprehensive overview of the main applications of transient elastography in the current clinical practice.

Factors associated with discordance in the assessment of fibrosis stage between transient elastography and liver biopsy in NAFLD patients

BACKGROUND AND AIMS

Few studies focus on the concordance of fibrosis stage assessment between transient elastography (TE) and liver biopsy (LB) in non-alcoholic fatty liver disease (NAFLD). This study aimed to investigate the rate of discordance and factors associated with discordance in the fibrosis stage assessment between TE and LB.

METHODS

LB-proven NAFLD patients were enrolled retrospectively. Liver fibrosis was assessed via TE and LB based on Steatosis-Activity-Fibrosis (SAF) criteria. Cohen's kappa was used to estimate the discordance between the fibrosis stage assessment by TE and LB. Logistic regression was utilized to determine the factors associated with discordance.

RESULTS

A total of 172 eligible patients were included. The concordance of fibrosis staging between TE and LB was moderate (kappa = 0.446, p < 0.001). The overall rate of discordance was 52.90% (91/172) and highest in the F2 stage (66.28%) and F3 stage (60.42%), moderate in the F1 stage (23.81%), and lowest in the F4 stage (0.00%). The rate of overestimation and underestimation was 23.66% and 38.71% in patients detected by M-probe, while the rate of overestimation and underestimation was 33.87% and 19.35% in patients detected by XL-probe, respectively. BMI [OR=1.494, p = 0.017] and type 2 diabetes mellitus (T2DM) (OR=4.678, p = 0.008) were significantly associated with the overestimation in fibrosis stage assessment when the M-probe was applied.

CONCLUSIONS

The discordance between TE and LB in fibrosis stage assessment was unexpectedly high and mainly observed in F1-F3 patients. BMI and T2DM were the factors associated with overestimation using the M-probe.

Comparison between Two-Dimensional and Point Shear Wave Elastography Techniques in Evaluating Liver Fibrosis Using Histological Staging as the Reference Standard: A Prospective Pilot Study

Evaluation of hepatic fibrosis is essential to prevent liver-related morbidity and mortality. Although various types of ultrasound shear wave elastography (SWE) have been used and validated, there are limited studies on the relatively newer technique, two-dimensional SWE (2D-SWE). Therefore, this study aimed to compare the diagnostic performances of 2D-SWE and point SWE (p-SWE) for evaluating liver fibrosis using histology as the reference standard. To measure liver stiffness (LS) values, 87 patients underwent 2D-SWE and p-SWE using the same machine. Technical failures and unreliable measurements were also evaluated. The diagnostic performances of 2D-SWE and p-SWE were compared using area under the receiver operating characteristic (AUROC) curve analysis. No technical failures were observed in either method; however, unreliable measurements were less frequent in 2D-SWE (1/87 [1.1%]) than in p-SWE (8/87 [9.2%]) (p < 0.001). The AUROC of the LS values of 2D-SWE were significantly higher than those of p-SWE for diagnosing significant fibrosis (0.965 vs. 0.872, p = 0.022) and cirrhosis (0.994 vs. 0.886, p = 0.042). In conclusion, 2D-SWE is more reliable and accurate than p-SWE for diagnosing hepatic fibrosis.

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.

Non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis belongs to the spectrum of metabolic-associated fatty liver diseases characterized by steatosis linked to obesity, diabetes, metabolic syndrome, dyslipidemia and immune-mediated disorders. The main features of MAFLD include high prevalence, heterogeneity, complexity and dynamic disease. Pruritus and asthenia are the main clinical manifestation that impact on quality of life and patient-reported outcomes. Biochemical or imagen-based non-invasive test have been implemented in the diagnostic process. Liver biopsy remains as the gold standard. Therapeutic options included life-style intervention. Mediterranean hypocaloric Diet to lose weight, exercise to fight sarcopenia and alcohol abstinence. In non-responders, drug-therapy focusing on obesity, diabetes and fibrosis using sequentially or combined to promote steatosis, inflammation and fibrosis regression.

Comparing 2D-shear wave to transient elastography for the evaluation of liver fibrosis in nonalcoholic fatty liver disease

BACKGROUND AND AIM

The aim of this study is to evaluate the performance of 2D-shear wave elastography (2D-SWE) in patients with nonalcoholic fatty liver disease (NAFLD) and compare it to transient elastography.

METHODS

Over 6 months, 552 patients with NAFLD underwent liver stiffness measurement (LSM) by both 2D-SWE and transient elastography with controlled attenuation parameter (CAP) at the same visit.

RESULTS

LSM was not feasible by transient elastography (M/XL probe) in 18 (3.3%) and by 2D-SWE in 26 (4.7%) patients. The median LSM of transient elastography was 5.5 (2.8-75) kPa and of 2D-SWE 6.2 (3.7-46.2) kPa. LSMs by transient elastography and 2D-SWE were correlated regardless of the obesity status (r, 0.774; P < 0.001; r, 0.774; P < 0.001; r, 0.75; P < 0.001 in BMI <25, 25-30 and ≥30 kg/m2 respectively), or the degree of liver steatosis (r = 0.63; P < 0.001 and r = 0.743; P < 0.001 in mild and moderate/severe steatosis, respectively). According to transient elastography, 88 (15.9%) patients were classified with at least severe fibrosis (≥F3) and 55 (10%) with cirrhosis. By using the 2D-SWE, 85 (15.4%) patients had at least severe fibrosis and 52 (9.4%) cirrhosis. The correlation between the two methods was strong in patients with at least severe fibrosis (r, 0.84; P < 0.001) or cirrhosis (r, 0.658; P < 0.001). When transient elastography was used as reference, 2D-SWE showed an excellent accuracy of 98.8 and 99.8% in diagnosing severe fibrosis and cirrhosis, respectively.

CONCLUSIONS

In NAFLD, 2D-SWE and transient elastography have comparable feasibility and clinical applicability providing LSMs with strong correlation, even in overweight/obese patients, independently of the severity of liver steatosis and fibrosis. Thus, either of the two methods can be effectively used for the assessment of fibrosis in this setting.

New horizon of ultrasound for screening and surveillance of non-alcoholic fatty liver disease spectrum

Non-alcoholic fatty liver disease (NAFLD) affects almost one quarter of adults worldwide, and its progressive subtype, non-alcoholic steatohepatitis can progress to advanced fibrosis/cirrhosis and even hepatocellular carcinoma. It is critical to screen and grade NAFLD patients for management decisions to rationalize the utilization of medical resources. Conventional ultrasound is widely applied for NAFLD screening, however, some inherent weaknesses hinder its utility. This limitation has spurred the development of acoustic parameters-based quantitative ultrasound techniques that allow a more accurate evaluation of the histological features of NAFLD (e.g. steatosis, necroinflammation, fibrosis/cirrhosis). Herein, this paper reviews the research advances in emerging ultrasound techniques for screening and surveillance across NAFLD spectrum and summarize their principles, feasibility, accuracy, reproducibility, and limitations of each technique. The challenges and future directions are also discussed to advance clinical practice.

Role of Ultrasound Methods for the Assessment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. The prevalence in patients with type 2 diabetes mellitus is between 55–80%. The spectrum of NALFD ranges from simple steatosis to aggressive steatohepatitis with potentially progressive liver fibrosis up to cirrhosis and hepatocellular carcinoma. In clinical practice, there are two important aims: First to make the diagnosis of NAFLD, and second, to identify patients with advanced fibrosis, because extent of fibrosis is strongly associated with overall mortality, cardiovascular disease, hepatocellular carcinoma, and extrahepatic malignancy. Histology by liver biopsy can deliver this information, but it is an invasive procedure with rare, but potentially severe, complications. Therefore, non-invasive techniques were developed to stage fibrosis. Ultrasound is the primary imaging modality in the assessment of patients with confirmed or suspected NAFLD. This narrative review focus on different ultrasound methods to detect and graduate hepatic steatosis and to determine grade of fibrosis using elastography-methods, such as transient elastography and 2-dimensional shear wave elastography in patients with NAFLD. Particular attention is paid to the application and limitations in overweight patients in clinical practice. Finally, the role of B-mode ultrasound in NAFLD patients to screen for hepatocellular carcinoma is outlined.

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.