Acoustic Radiation Force Impulse Elastography for the Non-Invasive Evaluation of Hepatic Fibrosis in Non-Alcoholic Fatty Liver Disease Patients: A Systematic Review & Meta-Analysis

Circulating microRNA panels in subjects with metabolic dysfunction-associated steatotic liver disease after following a 2-year dietary intervention

PURPOSE

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) affects one-third of the global population. Despite its high prevalence, there is a lack of minimally non-invasive diagnostic methods to assess this condition. This study explores the potential of circulating microRNAs (miRNAs) as diagnostic biomarkers for MASLD after a 2-year nutritional intervention.

METHODS

Fifty-five subjects with steatosis (MASLD group) from the Fatty Liver in Obesity (FLiO) study (NCT03183193) were analyzed at baseline and after 6, 12 and 24 months. Participants were classified into two groups: those who still had steatosis after the intervention (unhealthy group) and those in whom steatosis had disappeared (healthy group). Hepatic status was evaluated through magnetic resonance imaging (MRI), ultrasonography, elastography and serum transaminases. Circulating miRNA levels were measured by RT-PCR.

RESULTS

The dietary intervention was able to modulate the expression of circulating miRNAs after 6, 12, and 24 months. Logistic regression analyses revealed that the most effective panels for diagnosing whether MASLD has disappeared after the nutritional intervention included miR15b-3p, miR126-5p and BMI (AUC 0.68) at 6 months, miR29b-3p, miR122-5p, miR151a-3p and BMI (AUC 0.85) at 12 months and miR21-5p, miR151a-3p and BMI at 24 months (AUC 0.85).

CONCLUSIONS

Circulating miRNAs were useful in predicting MASLD in subjects with overweight or obesity after following a weight-loss oriented nutritional intervention. These findings highlight the potential role of miRNAs in diagnosing MASLD and underscore the importance of precision nutrition in managing and determining MASLD.

CLINICAL TRIAL REGISTRATION

Trial registration number: NCT03183193 (www.

CLINICALTRIALS

gov).

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.

Point Shear Wave Elastography for Assessment of Liver Stiffness in Normal Individuals and in Patients With Non-alcoholic Fatty Liver Disease

Background Non-alcoholic fatty liver disease (NAFLD) is an increasing health issue worldwide, driven by rising rates of diabetes, obesity, and hypertriglyceridemia. Often asymptomatic, NAFLD is diagnosed through blood tests, imaging, and sometimes liver biopsy. Some cases advance to non-alcoholic steatohepatitis (NASH), which can lead to complications like liver cirrhosis and liver failure. While liver biopsy is the standard test for diagnosis, non-invasive methods such as shear wave elastography (SWE) offer a simpler and more reproducible alternative for diagnosing NAFLD. This is crucial for early intervention and preventing the progression of liver damage. Objectives The objectives of the study were to measure and compare liver stiffness in healthy individuals and patients with NAFLD using point shear wave elastography (pSWE), as well as to correlate liver stiffness in NAFLD patients with the ultrasonographic grades of fatty liver. Materials and methods This observational study was carried out at Dr. D. Y. Patil Medical College, Hospital and Research Centre in Pune, India, from December 2022 to April 2024. The study involved 82 participants in total, with 41 patients diagnosed with NAFLD (cases) and 41 healthy individuals with a sonographically normal liver (controls). pSWE was performed on each participant to measure liver stiffness, with results expressed in kilopascals (kPa). The procedure was conducted using a Samsung HS70A ultrasound machine (Samsung Electronics Pvt. Ltd., Seoul, South Korea). Data analysis was performed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, New York, USA). Non-parametric tests, such as the Mann-Whitney test and Kruskal-Wallis test, were used to evaluate the significance of differences. A p-value of less than 0.05 was considered statistically significant. Results The mean liver stiffness, measured in kilopascals (kPa), was higher in NAFLD patients (cases) (10±5.1 kPa) than in normal individuals (controls) (4.4±0.7 kPa). This difference was statistically significant, with a p-value of less than 0.001. A positive correlation (rho=0.848, p<0.001) was found between the ultrasonographic grade of fatty liver and liver stiffness in NAFLD patients. Conclusion Our study demonstrated that individuals with NAFLD exhibited significantly higher liver stiffness compared to healthy individuals, as measured by ultrasound SWE. These findings suggest that pSWE could serve as a valuable, non-invasive diagnostic tool for assessing liver stiffness in NAFLD patients. Additionally, pSWE holds the potential for evaluating and monitoring the progression of the disease. However, further research with larger sample sizes is necessary to determine the prognostic significance of liver stiffness in these patients.

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.

Liver stiffness, hepatorenal index, and microRNA-130b as predictors for chronic kidney disease in patients with non-alcoholic fatty liver disease

Background and aim

Currently, nonalcoholic liver disease (NAFLD) is the most predominant chronic liver disorder. NAFLD has been linked to hepatic and extrahepatic morbidities. We aimed to investigate the role of acoustic radiation force impulse (ARFI), hepatorenal index (HRI), and serum microRNA-130b as non-invasive predictors for chronic kidney disease (CKD) in NAFLD patients.

Material and methods

In a case–control design, we included 40 NAFLD patients (20 NAFLD with CKD and 20 NAFLD without CKD) and 20 healthy controls. After clinical evaluation, laboratory assessments including liver test profile, renal function test, and quantification of microRNA-130b were done. Liver steatosis and stiffness were evaluated using HRI and ARFI.

Results

HRI and ARFI readings were significantly higher among NAFLD with CKD patients compared to other groups (P < 0.001). The median values of microRNA-130b were 32.1, 27.01, and 25.36 copies/µl in NAFLD with CKD, NAFLD without CKD, and healthy controls, respectively, with significant differences between groups (P < 0.05). ARFI values and HRI were positively correlated with microRNA-130b (P < 0.05). At a cutoff value > 28.13 copies/µl, microRNA-130b could differentiate between “NAFLD with CKD” and “NAFLD without CKD” patients with a sensitivity and specificity of 75% and 70%, respectively (AUC = 71.9%, P = 0.018).

Conclusions

Serum microRNA-130b, HRI, and ARFI are valuable noninvasive markers for the assessment of NAFLD. MicroRNA-130b is suggested as a sensitive biomarker for the prediction of CKD among NAFLD patients with good sensitivity and specificity.

Noninvasive biomarkers in pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide among children and adolescents. It encompasses a spectrum of disease, from its mildest form of isolated steatosis, to nonalcoholic steatohepatitis (NASH) to liver fibrosis and cirrhosis, or end-stage liver disease. The early diagnosis of pediatric NAFLD is crucial in preventing disease progression and in improving outcomes. Currently, liver biopsy is the gold standard for diagnosing NAFLD. However, given its invasive nature, there has been significant interest in developing noninvasive methods that can be used as accurate alternatives. Here, we review noninvasive biomarkers in pediatric NAFLD, focusing primarily on the diagnostic accuracy of various biomarkers as measured by their area under the receiver operating characteristic, sensitivity, and specificity. We examine two major approaches to noninvasive biomarkers in children with NAFLD. First, the biological approach that quantifies serological biomarkers. This includes the study of individual circulating molecules as biomarkers as well as the use of composite algorithms derived from combinations of biomarkers. The second is a more physical approach that examines data measured through imaging techniques as noninvasive biomarkers for pediatric NAFLD. Each of these approaches was applied to children with NAFLD, NASH, and NAFLD with fibrosis. Finally, we suggest possible areas for future research based on current gaps in knowledge.

How to Identify Advanced Nonalcoholic Fatty Liver Disease in the Primary Care Setting

Nonalcoholic fatty liver disease (NAFLD) affects 30 to 40% of the population globally and is increasingly considered the most common liver disease. Patients with type 2 diabetes, obesity, and cardiovascular diseases are at especially increased risk for NAFLD. Although most patients with NAFLD do not have progressive liver disease, some patients progress to cirrhosis, liver cancer, and liver mortality. Given the sheer number of patients with NAFLD, the burden of disease is enormous. Despite this large and increasing burden, identification of NAFLD patients at risk for progressive liver disease in the primary care and diabetology practice settings remains highly suboptimal. In this review, our aim is to summarize a stepwise approach to risk stratify patients with NAFLD which should help practitioners in their management of patients with NAFLD.

Point Shear Wave Elastography by ElastPQ for Fibrosis Screening in Patients with NAFLD: A Prospective, Multicenter Comparison to Vibration-Controlled Elastography

BACKGROUND

Since nonalcoholic fatty liver disease (NAFLD) has become the leading cause of liver disease in the Western world, clinicians need reliable noninvasive tools for the identification of NAFLD-associated fibrosis. Limited evidence on the performance of the novel shear wave elastography technique Elast-PQ (EPQ) in NAFLD is available.

METHOD

In this prospective, European multinational study we assessed the diagnostic accuracy of EPQ using vibration-controlled transient elastography (VCTE) as a reference standard.

RESULTS

Among 353 NAFLD patients, 332 (94.1%) fulfilled reliability criteria of VCTE and EPQ (defined by IQR/median ≤0.3; 41.3% female, mean age: 59 [IQR: 16.5], mean BMI: 29.0 (7.1)). 4/353 (1.1%) and 17/353 (4.8%) had unreliable VCTE and EPQ measurements, respectively. VCTE-based NAFLD fibrosis stages were F0/F1: 222(66.9%), F2: 41 (12.3%), F3: 30 (9.1%), F4: 39 (11.7%). We found a strong correlation (Pearson R=0.87; p<0.0001) and concordance (Lin's concordance correlation coefficient =0.792) of EPQ with VCTE. EPQ was able to identify NAFLD-fibrosis risk with the following EPQ cutoffs: ≥6.5 kPa for significant fibrosis (≥F2) (≥1.47 m/s; sensitivity: 78%; specificity: 95%; AUROC: 0.94), ≥6.9 kPa for advanced fibrosis (≥F3) (≥1.52 m/s; sens.: 88%, spec.: 89%; AUROC: 0.949), and ≥10.4 kPa for cirrhosis (F4) (≥1.86 m/s; sens.: 87%; spec.: 94%; AUROC: 0.949).

CONCLUSION

The point shear wave elastography technique EPQ shows excellent correlation to and concordance with VCTE. EPQ can reliably exclude NAFLD fibrosis <6.0 kPa (<1.41 m/s) and indicate a high risk of advanced fibrosis ≥10.4 kPa (≥1.86 m/s).

Liver Ultrasound Elastography in Non-Alcoholic Fatty Liver Disease: A State-of-the-Art Summary

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease which is currently the most common hepatic disorder affecting up to 38% of the general population with differences according to age, country, ethnicity and sex. Both genetic and acquired risk factors such as a high-calorie diet or high intake of saturated fats have been associated with obesity, diabetes and, finally, NAFLD. A liver biopsy has always been considered essential for the diagnosis of NAFLD; however, due to several limitations such as the potential occurrence of major complications, sampling variability and the poor repeatability in clinical practice, it is considered an imperfect option for the evaluation of liver fibrosis over time. For these reasons, a non-invasive assessment by serum biomarkers and the quantification of liver stiffness is becoming the new frontier in the management of patients with NAFLD and liver fibrosis. We present a state-of-the-art summary addressing the methods for the non-invasive evaluation of liver fibrosis in NAFLD patients, particularly the ultrasound-based techniques (transient elastography, ARFI techniques and strain elastography) and their optimal cut-off values for the staging of liver fibrosis.

Validation of a screening algorithm for hepatic fibrosis by Doppler ultrasound and elastography in a general population

BACKGROUND

Early detection can prevent the initial stages of fibrosis from progressing to cirrhosis.

PURPOSE

To evaluate an algorithm combining three echographic indicators and elastographic measurements to screen for hepatic fibrosis in an unselected population.

MATERIAL AND METHODS

From May 2017 to June 2018, all patients with no history and no known chronic liver disease who were referred for an ultrasound (US) were prospectively included in eight hospitals. The indicators being sought were liver surface irregularity, demodulation of hepatic veins, and spleen length >110 mm. Patients presenting at least one of these underwent elastography measurements with virtual touch quantification (VTQ) or supersonic shear imaging (SSI). If elastography was positive, patients were referred to hepatologist for fibrosis evaluation. Reference standard was obtained by FibroMeter^VCTE or biopsy. A FibroMeter^VCTE result >0.384 indicated a "necessary referral" to a hepatologist.

RESULTS

Of the 1501 patients included, 504 (33.6%) were positive for at least one US indicator. All of them underwent US elastography, with 85 being positive. Of the patients, 58 (3.6%) had a consultation with a liver specialist: 21 had positive FibroMeter^VCTE and nine had an indication of biopsy for suspicion of fibrosis. This screening algorithm made it possible to diagnose 1.6% of patients in our population with unknown fibrosis. Of the patients, 50% referred to the liver specialist were "necessary referrals."

CONCLUSION

Our study suggests that three simple US indicators with no systematic elastographic measurement could be applied in day-to-day practice to look for hepatic fibrosis in an unsuspected population allowing relevant referrals to a hepatologist.

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.

Diagnostic Modalities of Non-Alcoholic Fatty Liver Disease: From Biochemical Biomarkers to Multi-Omics Non-Invasive Approaches

Non-Alcoholic Fatty Liver Disease (NAFLD) is currently the most common cause of chronic liver disease worldwide, and its prevalence is increasing globally. NAFLD is a multifaceted disorder, and its spectrum includes steatosis to steatohepatitis, which may evolve to advanced fibrosis and cirrhosis. In addition, the presence of NAFLD is independently associated with a higher cardiometabolic risk and increased mortality rates. Considering that the vast majority of individuals with NAFLD are mainly asymptomatic, early diagnosis of non-alcoholic steatohepatitis (NASH) and accurate staging of fibrosis risk is crucial for better stratification, monitoring and targeted management of patients at risk. To date, liver biopsy remains the gold standard procedure for the diagnosis of NASH and staging of NAFLD. However, due to its invasive nature, research on non-invasive tests is rapidly increasing with significant advances having been achieved during the last decades in the diagnostic field. New promising non-invasive biomarkers and techniques have been developed, evaluated and assessed, including biochemical markers, imaging modalities and the most recent multi-omics approaches. Our article provides a comprehensive review of the currently available and emerging non-invasive diagnostic tools used in assessing NAFLD, also highlighting the importance of accurate and validated diagnostic tools.

Shear Wave Elastography Reveals a High Prevalence of NAFLD-related Fibrosis Even in Type 1 Diabetes

BACKGROUND

The association between type 2 diabetes mellitus (T2DM) and advanced stages of non-alcoholic fatty liver disease is well known. Some studies indicate a relevant prevalence also in type 1 diabetes mellitus (T1DM), but so far there is only limited data.

OBJECTIVE

To determine the prevalence of non-alcoholic fatty liver disease (NAFLD)-related liver fibrosis in individuals with T1DM and compare to those with type 2 diabetes.

METHODS

Diabetic patients from a single diabetes care centre were screened for liver fibrosis by sonographic shear wave elastography (SWE). In addition, all patients received laboratory evaluation including non-alcoholic fatty liver fibrosis score and Fibrosis-4 Index.

RESULTS

Three hundred and forty patients were included in the study, of these, 310 received SWE. Overall 254 patients (93 with type 1 and 161 with type 2 diabetes) had reliable measurements and were included in the final analysis. In patients with type 1 diabetes, the prevalence of NAFLD-related liver fibrosis was 16-21%, depending on the method of detection. Significant liver fibrosis was observed in 30-46% of patients with type 2 diabetes.

CONCLUSIONS

Our data revealed an unexpectedly high prevalence of NAFLD-related liver fibrosis in patients with type 1 diabetes. To our knowledge, this is one of the first studies using SWE to diagnose advanced NAFLD in type 1 diabetes in a non-preselected cohort. Considering the findings of our study, regular screening for hepatic complications must be recommended for all diabetic patients, even for those with type 1 diabetes.

Serum Mac-2 Binding Protein Glycosylation Isomer (M2BPGi) Can Predict Mild or Significant Liver Fibrosis in Non-alcoholic Fatty Liver Disease

Background: The serum levels of M2BPGi increase with liver fibrosis progression in patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. However, the diagnostic performance of M2BPGi in non-alcoholic fatty liver disease (NAFLD) patients remains unclear. Objectives: To assess the severity of liver fibrosis in NAFLD patients and healthy controls by M2BPGi using acoustic radiation force impulse (ARFI) as the standard reference. Methods: Those suffering from NAFLD and healthy controls were recruited. NAFLD diagnosis was confirmed using fatty liver in imaging after excluding HCV, HBV, alcohol, drug, or other known causes of chronic liver disease. ARFI was used as the standard reference to determine the stage of liver fibrosis. Results: A total of 226 subjects were recruited, including 130 (57.5%) NAFLD patients who were divided into three groups according to the stage of liver fibrosis: F0, F1, and F ≥ 2. The serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST to platelet ratio index (APRI), M2BPGi, and the fatty liver grade were significantly different between the three groups. The levels of M2BPGi were correlated with median ARFI value (P < 0.001), APRI (P = 0.011), and fibrosis 4 index (FIB-4) (P < 0.001). The area under the curve (AUC) of M2BPGi test was 0.58 for F ≥ 1 and 0.68 for F ≥ 2, respectively (P = 0.039 and P = 0.024). Conclusions: The M2BPGi levels were correlated with ARFI, APRI, and FIB-4 scores in this study population. The level of M2BPGi could predict mild (F ≥ 1) and significant liver fibrosis (F ≥ 2) in NAFLD patients, suggesting a surrogate marker to differentiate between normal, mild, and significant fibrosis.

Effects of two personalized dietary strategies during a 2-year intervention in subjects with nonalcoholic fatty liver disease: A randomized trial

BACKGROUND AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) management is focused on lifestyle modifications, but long-term maintenance is a challenge for many individuals. This study aimed to evaluate the long-term effects of two personalized energy-restricted dietary strategies on weight loss, metabolic and hepatic outcomes in overweight/obese subjects with NAFLD.

METHODS

Ninety-eight subjects from the Fatty Liver in Obesity (FLiO) study (NCT03183193) were randomly assigned to the American Heart Association (AHA) or the FLiO dietary group in a 2-year controlled trial. Anthropometry, body composition (DXA), biochemical parameters and hepatic status (ultrasonography, Magnetic Resonance Imaging, and elastography) were assessed at baseline, 6, 12 and 24 months.

RESULTS

Both the AHA and FLiO diets significantly reduced body weight at 6 (-9.7% vs -10.1%), 12 (-6.7% vs -9.6%), and 24 months (-4.8% vs -7.6%) with significant improvements in body composition, biochemical and liver determinations throughout the intervention. At the end of the follow-up, the FLiO group showed a greater decrease in ALT, liver stiffness and Fatty Liver Index, among others, compared to AHA group, although these differences were attenuated when the analyses were adjusted by weight loss percentage. The FLiO group also showed a greater increase in adiponectin compared to AHA group.

CONCLUSIONS

The AHA and FLiO diets were able to improve body weight and body composition, as well as metabolic and hepatic status of participants with overweight/obesity and NAFLD within a 2-year follow-up. These findings show that both strategies are suitable alternatives for NAFLD management. However, the FLiO strategy may provide more persistent benefits in metabolic and hepatic parameters.

The role of elastography in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its prevalence is even higher in patients with risk factors such as type 2 diabetes and obesity. Liver biopsy is the gold standard for diagnosis of non-alcoholic steatohepatitis (NASH), particularly for the assessment of fibrosis stage that is a key prognostic factor. Noninvasive methods for assessment of liver fibrosis are a huge need in contemporary hepatology in order to stratify patient's risk of advanced and progressive liver disease. In this perspective different imaging techniques have been developed in last decades and showed high performance in liver fibrosis evaluation. Strengths and weaknesses of all imaging methods are summarized in this review.

Perspectives on Precision Medicine Approaches to NAFLD Diagnosis and Management

Precision medicine defines the attempt to identify the most effective approaches for specific subsets of patients based on their genetic background, clinical features, and environmental factors. Nonalcoholic fatty liver disease (NAFLD) encompasses the alcohol-like spectrum of liver disorders (steatosis, steatohepatitis with/without fibrosis, and cirrhosis and hepatocellular carcinoma) in the nonalcoholic patient. Recently, disease renaming to MAFLD [metabolic (dysfunction)-associated fatty liver disease] and positive criteria for diagnosis have been proposed. This review article is specifically devoted to envisaging some clues that may be useful to implementing a precision medicine-oriented approach in research and clinical practice. To this end, we focus on how sex and reproductive status, genetics, intestinal microbiota diversity, endocrine and metabolic status, as well as physical activity may interact in determining NAFLD/MAFLD heterogeneity. All these factors should be considered in the individual patient with the aim of implementing an individualized therapeutic plan. The impact of considering NAFLD heterogeneity on the development of targeted therapies for NAFLD subgroups is also extensively discussed.

Diagnostic Value of Ultrasound in Fatty Liver Disease

Hepatic steatosis is a commonly seen phenomenon in clinical practice and is the result of the accumulation of lipids in the hepatocytes. In most cases steatosis refers to nonalcoholic fatty liver disease (NAFLD), but it also occurs in other diseases of the liver parenchyma of a different etiology and is the result of the dysregulation of metabolic processes. Consequently, inflammatory processes can induce progressive fibrosis. Due to the high prevalence of fatty liver disease, a further increase in metabolic liver cirrhosis with corresponding complications can be expected in the near future. Due to its broad availability, ultrasound is particularly important, especially for the management of NAFLD. In addition to diagnosis and risk stratification, the monitoring of high-risk patients in NAFLD is becoming increasingly clinically important. Multimodality ultrasound includes B-mode and duplex methods, analysis of tissue stiffness (elastography), contrast-enhanced imaging (CEUS), and steatosis quantification. When using ultrasound in fatty liver disease, a standardized approach that takes into account the limitations of the method is essential.

(13C)-Methacetin breath test provides evidence of subclinical liver dysfunction linked to fat storage but not lifestyle

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is characterised by the presence of hepatic steatosis in the absence of other causes of secondary hepatic fat accumulation, and is usually associated with visceral, metabolically active obesity. However, the subclinical effects of body and liver fat accumulation on liver function are still unclear.

METHODS

We used orally administered (¹³C)-methacetin and breath test to quantify the efficiency of hepatic extraction from portal blood flow and liver microsomal function in 81 participants, in relation to presence/absence of ultrasonographic NAFLD, extent of body fat accumulation, insulin resistance, dietary models, and lifestyle.

RESULTS

NAFLD was present in 23% of participants with normal weight, and prevalence increased with body fat and insulin resistance. Fat accumulation, NAFLD, and insulin resistance were associated with decreased hepatic extraction efficiency, and liver microsomal function was impaired in moderate-to-severe NAFLD. Caloric intake, dietary models, and lifestyles had a minor role in promoting functional changes.

CONCLUSIONS

The interplay between body fat accumulation, insulin resistance, and NAFLD is linked with altered hepatic extraction efficiency from blood flow and deranged microsomal function. Non-invasive diagnosis of subclinical alterations of liver function is relevant for primary and secondary prevention measures. Furthermore, the occurrence of NAFLD in lean individuals and the evidence that caloric intake, dietary models, and lifestyle played a minor role require further studies exploring the role of environmental factors in the natural history of these diseases.

LAY SUMMARY

Obesity is progressively increasing worldwide and is paralleled by fat accumulation in the liver (non-alcoholic fatty liver disease [NAFLD]), the most common chronic liver disease worldwide. NAFLD can alter liver structure and function, with a variety of consequences ranging from asymptomatic and subclinical alterations to cirrhosis and cancer. (¹³C)-Methacetin breath test, a non-invasive diagnostic tool, can reveal early subclinical alterations of liver dynamic function in individuals with obesity and in patients with NAFLD.

Liver stiffness quantification in biopsy-proven nonalcoholic fatty liver disease patients using shear wave elastography in comparison with transient elastography

Purpose

This study prospectively assessed the performance of liver stiffness measurements using point shear-wave elastography (p-SWE) in comparison with transient elastography (TE) in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD).

Methods

Fifty-six consecutive adult patients with a histological diagnosis of NAFLD prospectively underwent TE and p-SWE on the same day. The median of 10 measurements (SWE-10), the first five (SWE-5), and the first three (SWE-3) measurements were analyzed for p-SWE. Liver biopsy was considered as the reference standard for liver fibrosis grade. Receiver operating characteristic (ROC) curves and areas under the ROC curves (AUROCs) were calculated to assess the performance of TE and p-SWE for the diagnosis of significant (F2-F4) and advanced fibrosis (F3-F4).

Results

Forty-six patients (27 men, 19 women; mean age, 54.7±9.1 years) had valid p-SWE and TE measurements. Twenty-seven patients (58.7%) had significant fibrosis and 18 (39.1%) had advanced fibrosis. For significant fibrosis, both SWE-10 (AUROC, 0.787; P=0.002) and SWE-5 (AUROC, 0.809; P=0.001) provided higher diagnostic performance than TE (AUROC, 0.719; P=0.016) and SWE-3 (AUROC, 0.714; P=0.021), albeit without statistical significance (P=0.301). For advanced fibrosis, SWE-5 showed higher diagnostic performance (AUROC, 0.809; P<0.001) than TE (AUROC, 0.799; P<0.001), SWE-10 (AUROC, 0.797; P<0.001), and SWE-3 (AUROC, 0.736; P=0.003), although the differences were not statistically significant (P=0.496). The optimal SWE-10 and SWE-5 cutoff values were ≥8.4 and ≥7.8 for significant fibrosis, and ≥9.1 and ≥8.8 for advanced fibrosis, respectively.

Conclusion

TE and p-SWE showed similar performance for the diagnosis of significant and advanced fibrosis in NAFLD patients.

The Role of Elastography in Non-Alcoholic Fatty Liver Disease

The most common liver disease in developing countries is non-alcoholic fatty liver disease (NAFLD). This involves the abnormal accumulation of lipids in the liver, the pathogenesis of the disease being related to dyslipidemia, obesity, insulin resistance and type 2 diabetes. Most often, the diagnosis of NAFLD is incidental, when performing routine blood tests or when performing a transabdominal ultrasound. The NAFLD spectrum ranges from simple forms of hepatic steatosis to the most advanced form of the disease, steatohepatitis (NASH), which in evolution can cause inflammation, fibrosis, cirrhosis of the liver and even liver cancer. For the evaluation of the prognosis and the clinical evolution, the most important parameter to define is the degree of liver fibrosis. Currently, the gold standard remains the liver biopsy, the differentiation between NAFLD and NASH being made only on the basis of histological analysis. However, liver biopsy is an invasive procedure, with numerous risks such as bleeding, lesions of the other organs and complications related to anesthesia, which significantly reduces its widespread use. Moreover, the risk of a false negative result and the increased costs of the procedure further limits its use in current practice. For this reason, non-invasive methods of evaluating the degree of liver fibrosis have gained ground in recent years. Imaging techniques such as elastography have shown promising results in evaluating and staging NAFLD. The aim of this article is to review the current status of the non-invasive tests for the assessment of NAFLD with a focus on the ultrasound-based elastography techniques.

Optimization of Point-Shear Wave Elastography by Skin-to-Liver Distance to Assess Liver Fibrosis in Patients Undergoing Bariatric Surgery

BACKGROUND

Obesity is a primary limiting factor in liver stiffness measurement (LSM). The impact of obesity has always been evaluated in terms of body mass index (BMI), without studying the effects of skin-to-liver distance (SLD) on LSM. We studied the impact of SLD on LSM in a cohort of obese patients undergoing bariatric surgery and intra-operatory liver biopsy.

MATERIALS AND METHODS

299 patients underwent LSM by point-shear wave elastography (ElastPQ protocol), with two different ultrasound machines. SLD was measured as the distance between the skin and the liver capsule, perpendicular to where the region of interest (ROI) was positioned. We used the following arbitrary cut-offs: <5.7 kPa, F0-1; 5.7-7.99 kPa, F2; ≥8 kPa, F3-4.

RESULTS

We developed two logistic regression models using elastography-histology agreement (EHA) as the dependent variable and SLD as the independent variable. The model based on the second machine showed strongly more performant discriminative and calibration metrics (AIC 38.5, BIC 44.2, Nagelkerke Pseudo-R2 0.894, AUROC 0.90). The SLD cut-off value of 34.5 mm allowed a correct EHA with a sensitivity of 100%, a specificity of 93%, negative predictive value of 100%, positive predictive value of 87%, an accuracy of 96%, and positive likelihood ratio of 3.56.

CONCLUSION

The impact of SLD is machine-dependent and should be taken into consideration when interpreting LSM. We believe that our findings may serve as a reference point for appropriate fibrosis stratification by liver elastography in obese patients.

Hepatocellular Carcinoma and Non-Alcoholic Fatty Liver Disease: A Step Forward for Better Evaluation Using Ultrasound Elastography

Simple Summary

Non-alcoholic fatty liver disease (NAFLD) attracts a lot of attention, due to the increasing prevalence and progression to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Consequently, new non-invasive, cost-effective diagnostic methods are needed. This review aims to explore the diagnostic performance of ultrasound (US) elastography in NAFLD and NAFLD-related HCC, adding a new dimension to the conventional US examination—the liver stiffness quantification. The vibration controlled transient elastography (VCTE), and 2D-Shear wave elastography (2D-SWE) are effective in staging liver fibrosis in NAFLD. VCTE presents the upside of assessing steatosis through the controlled attenuation parameter. Hereby, we critically reviewed the elastography techniques for the quantitative characterization of focal liver lesions (FLLs), focusing on HCC: Point shear wave elastography and 2D-SWE. 2D-SWE presents a great potential to differentiate malignant from benign FLLs, guiding the clinician towards the next diagnostic steps. As a disease-specific surveillance tool, US elastography presents prognostic capability, improving the NAFLD-related HCC monitoring.

Abstract

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) in the general population prompts for a quick response from physicians. As NAFLD can progress to liver fibrosis, cirrhosis, and even hepatocellular carcinoma (HCC), new non-invasive, rapid, cost-effective diagnostic methods are needed. In this review, we explore the diagnostic performance of ultrasound elastography for non-invasive assessment of NAFLD and NAFLD-related HCC. Elastography provides a new dimension to the conventional ultrasound examination, by adding the liver stiffness quantification in the diagnostic algorithm. Whilst the most efficient elastographic techniques in staging liver fibrosis in NAFLD are vibration controlled transient elastography (VCTE) and 2D-Shear wave elastography (2D-SWE), VCTE presents the upside of assessing steatosis through the controlled attenuation parameter (CAP). Hereby, we have also critically reviewed the most important elastographic techniques for the quantitative characterization of focal liver lesions (FLLs), focusing on HCC: Point shear wave elastography (pSWE) and 2D-SWE. As our paper shows, elastography should not be considered as a substitute for FLL biopsy because of the stiffness values overlap. Furthermore, by using non-invasive, disease-specific surveillance tools, such as US elastography, a subset of the non-cirrhotic NAFLD patients at risk for developing HCC can be detected early, leading to a better outcome. A recent ultrasomics study exemplified the wide potential of 2D-SWE to differentiate benign FLLs from malignant ones, guiding the clinician towards the next steps of diagnosis and contributing to better long-term disease surveillance.

The diagnostic conundrum in non-alcoholic fatty liver disease

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

Advances in ultrasound elastography for nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) has increased rapidly worldwide, making NAFLD/NASH an important global health problem from both a medical and socioeconomic standpoint. NAFLD is also regarded as a liver component of metabolic syndrome and is reported to be associated with the risk factors for metabolic syndrome. It has been suggested that NAFLD/NASH be recognized both as a liver-specific disease and as an early mediator of systemic diseases. Liver biopsy is recommended as the gold standard method for the diagnosis of NASH and for the staging of liver fibrosis in patients with NAFLD. However, because of its high cost, high risk, and high weightage as a healthcare resource, invasive liver biopsy is a poorly suited diagnostic test for such a highly prevalent condition. Therefore, the development of reliable noninvasive methods for the assessment of liver fibrosis has been sought to estimate the risk of progression of NASH to cirrhosis, estimate the risk of cardiovascular events, aid in the surveillance for HCC, and guide therapy in patients with NAFLD/NASH. In this review, we highlight the principles and recent advances in ultrasound elastography techniques (Real-time Tissue Elastography^®, vibration-controlled transient elastography, point shear wave elastography, and two-dimensional shear wave elastography) used to evaluate the liver fibrosis stage and steatosis grade in patients with NAFLD.

Elastography Techniques for the Assessment of Liver Fibrosis in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is expected to increase in prevalence because of the ongoing epidemics of obesity and diabetes, and it has become a major cause of chronic liver disease worldwide. Liver fibrosis is associated with long-term outcomes in patients with NAFLD. Liver biopsy is recommended as the gold standard method for the staging of liver fibrosis. However, it has several problems. Therefore, simple and noninvasive methods for the diagnosis and staging of liver fibrosis are urgently needed in place of biopsy. This review discusses recent studies of elastography techniques (vibration-controlled transient elastography, point shear wave elastography, two-dimensional shear wave elastography, and magnetic resonance elastography) that can be used for the assessment of liver fibrosis in patients with NAFLD.

Non-invasive diagnosis: non-alcoholic fatty liver disease and alcoholic liver disease

Non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are becoming the leading causes of chronic liver disease worldwide, significantly impacting public health and healthcare cost. The development of fibrosis is the main factor leading to early mortality and morbidity in NAFLD and ALD. Thus, it is important to timely and reliably evaluate these diseases at early stages, when fibrosis is not advanced or when steatosis predominates. Liver biopsy has been the standard of reference for fibrosis and steatosis, however, its invasiveness precludes its widespread use. There is growing research on non-invasive methods for diagnosing and stratifying fibrosis and steatosis in NAFLD and ALD. This review presents clinical evidence on the use of non-invasive assessment of liver disease (blood-based and imaging-based) in patients with NALFD and ALD, and proposes algorithms incorporating these tests into their management.

How to Identify the Patient with Nonalcoholic Steatohepatitis Who Will Progress to Cirrhosis

Non-alcoholic fatty liver disease (NAFLD) figures prominently into the clinical hepatology landscape. NAFLD represents a disease spectrum comprising simple steatosis, steatosis with elevated liver enzymes, and non-alcoholic steatohepatitis (NASH), the entity with clear potential for fibrosis progression. Risk factors associated with fibrosis progression in NASH include histologic findings of lobular inflammation and any fibrosis as well as clinical comorbidities that include type 2 diabetes, obesity, and metabolic syndrome. Liver biopsy remains the gold standard in evaluating NASH; however, noninvasive methods are accumulating evidence for a growing role in identifying patients at increased risk to develop NASH, fibrosis, and potentially cirrhosis.

Increased Colonic Permeability and Lifestyles as Contributing Factors to Obesity and Liver Steatosis

Intestinal permeability (IP) is essential in maintaining gut-metabolic functions in health. An unequivocal evaluation of IP, as marker of intestinal barrier integrity, however, is missing in health and in several diseases. We aimed to assess IP in the whole gastrointestinal tract according to body mass index (BMI) and liver steatosis. In 120 patients (61F:59M; mean age 45 ± SEM 1.2 years, range: 18-75), IP was distinctively studied by urine recovery of orally administered sucrose (SO, stomach), lactulose/mannitol ratio (LA/MA, small intestine), and sucralose (SA, colon). By triple quadrupole mass-spectrometry and high-performance liquid chromatography, we measured urinary recovery of saccharide probes. Subjects were stratified according to BMI as normal weight, overweight, and obesity, and answered questionnaires regarding dietary habits and adherence to the Mediterranean Diet. Liver steatosis was assessed by ultrasonography. IP at every gastrointestinal tract was similar in both sexes and decreased with age. Stomach and small intestinal permeability did not differ according to BMI. Colonic permeability increased with BMI, waist, neck, and hip circumferences and was significantly higher in obese than in lean subjects. As determined by logistic regression, the odds ratio (OR) of BMI increment was significantly higher in subjects in the highest tertile of sucralose excretion, also after adjusting for age and consumption of junk food. The presence of liver steatosis was associated with increased colonic permeability. Patients with lower score of adherence to Mediterranean diet had a higher score of 'junk food'. Intestinal permeability tended to increase in subjects with a lower adherence to Mediterranean diet. In conclusion, colonic (but not stomach and small intestinal) permeability seems to be linked to obesity and liver steatosis independently from dietary habits, age, and physical activity. The exact role of these last factors, however, requires specific studies focusing on intestinal permeability. Results should pave the way to both primary prevention measures and new therapeutic strategies in metabolic and liver diseases.

The diagnostic accuracy of liver fibrosis in non-viral liver diseases using acoustic radiation force impulse elastography: A systematic review and meta-analysis

BACKGROUND

Acoustic radiation force impulse (ARFI) imaging is an ultrasound-based elastography method that has been studied in the staging of hepatic fibrosis, especially in chronic hepatitis. However, the diagnostic accuracy of ARFI in non-viral hepatopathies, such as autoimmune hepatitis and non-alcoholic fatty liver disease, has not been systematically determined.

AIM

To systematically assess the diagnostic accuracy of ARFI in non-viral hepatopathies.

METHODS

The databases of PubMed, Embase, Cochrane Library and clinicaltrials.gov were systematically searched for candidate studies reporting the diagnostic accuracy of ARFI for hepatic fibrosis. The pooled estimates of the sensitivity, specificity, diagnostic odds ratio, and positive and negative likelihood ratios were calculated with the summary receiver operating curve (sROC) performed using STATA software.

RESULTS

In detail, a total of 29 diagnostic studies were included for further analysis. The quality of the included studies was relatively high using QUADAS method. The pooled sensitivity and specificity were 0.79 (0.73, 0.83) and 0.81 (0.75, 0.86), with AUROC 0.87 (0.83, 0.89) for the staging of significant fibrosis (F≥2). Meanwhile, for the staging of severe fibrosis (F≥3), the pooled sensitivity and specificity were 0.92 (0.87, 0.95) and 0.85 (0.80, 0.89), with AUROC 0.94 (0.92, 0.96). Furthermore, the pooled sensitivity and specificity were 0.89 (0.79, 0.95) and 0.89 (0.85, 0.92), with AUROC 0.94 (0.92, 0.96) for ARFI in staging cirrhosis (F = 4), which were similar to the data for severe fibrosis. No significant publication bias was present in this study.

CONCLUSION

This meta-analysis demonstrated that ARFI exerted satisfactory diagnostic performance in staging non-viral hepatic fibrosis, especially severe fibrosis (F≥3) and cirrhosis (F = 4).

The Metabolic and Hepatic Impact of Two Personalized Dietary Strategies in Subjects with Obesity and Nonalcoholic Fatty Liver Disease: The Fatty Liver in Obesity (FLiO) Randomized Controlled Trial

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide. NAFLD management is mainly focused on weight loss, but the optimal characteristics of the diet demand further investigation. This study aims to evaluate the effects of two personalized energy-restricted diets on the liver status in overweight or obese subjects with NAFLD after a 6 months follow-up. Ninety-eight individuals from the Fatty Liver in Obesity (FLiO) study were randomized into two groups and followed different energy-restricted diets. Subjects were evaluated at baseline and after 6 months. Diet, anthropometry, body composition, and biochemical parameters were evaluated. Liver assessment included ultrasonography, Magnetic Resonance Imaging, elastography, and determination of transaminases. Both dietary groups significantly improved their metabolic and hepatic markers after the intervention, with no significant differences between them. Multivariate regression models evidenced a relationship between weight loss, adherence to the Mediterranean Diet (MedDiet), and a decrease in liver fat content, predicting up to 40.9% of its variability after 6 months. Moreover, the antioxidant capacity of the diet was inversely associated with liver fat content. Participants in the group with a higher adherence to the MedDiet showed a greater reduction in body weight, total fat mass, and hepatic fat. These results support the benefit of energy-restricted diets, high adherence to the MedDiet, and high antioxidant capacity of the diet for the management of NAFLD in individuals with overweight or obesity.

Overview of the Pathogenesis, Genetic, and Non-Invasive Clinical, Biochemical, and Scoring Methods in the Assessment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide. It represents a range of disorders, including simple steatosis, nonalcoholic steatohepatitis (NASH), and liver cirrhosis, and its prevalence continues to rise. In some cases, hepatocellular carcinoma (HCC) may develop. The develop;ment of non-invasive diagnostic and screening tools is needed, in order to reduce the frequency of liver biopsies. The most promising methods are those able to exclude advanced fibrosis and quantify steatosis. In this study, new perspective markers for inflammation, oxidative stress, apoptosis, and fibrogenesis; emerging scoring models for detecting hepatic steatosis and fibrosis; and new genetic, epigenetic, and multiomic studies are discussed. As isolated biochemical parameters are not specific or sensitive enough to predict the presence of NASH and fibrosis, there is a tendency to use various markers and combine them into mathematical algorithms. Several predictive models and scoring systems have been developed. Current data suggests that panels of markers (NAFLD fibrosis score, Fib-4 score, BARD score, and others) are useful diagnostic modalities to minimize the number of liver biopsies. The review unveils pathophysiological aspects related to new trends in current non-invasive biochemical, genetic, and scoring methods, and provides insight into their diagnostic accuracies and suitability in clinical practice.

Liver fibrosis markers as assessed by ultrasound elastography and serum samples: A large comparative study in hepatitis virus B and C liver diseases

AIM

We aimed to compare the well-established liver fibrosis (LF) markers in Japanese patients with chronic hepatitis B (CHB, n = 331) and chronic hepatitis C (CHC, n = 886) and to discuss possible causes of differences in results between CHB patients and CHC patients.

METHODS

Virtual touch quantification (VTQ) in acoustic radiation force impulse, Fibrosis-4 (Fib-4) index, aspartate aminotransferase to platelet ratio index (APRI), and hyaluronic acid (HA) were compared between the two cohorts. As an additional investigation, total collagen proportional area (TCPA, %) was tested using liver pathological samples (n = 83).

RESULTS

Significant LF (F2 or greater) and advanced LF (F3 or greater) were identified in 153 (46.2%) and 76 (23.0%) patients in the CHB cohort and 579 (65.3%) and 396 (44.7%) patients in the CHC cohort. The median VTQ, Fib-4 index, APRI, and HA values in the CHB cohort were 1.20 m/s, 1.36, 0.44, and 25 ng/mL; those in the CHC cohort were 1.32 m/s, 2.60, 0.74, and 65.5 ng/mL (P-values, all <0.0001). Similar tendencies were noted by F stage-based stratification. The median TCPA in the CHB cohort and the CHC cohort were 8.5% and 12.7% (P < 0.0006). The TCPA values in the CHC cohort were higher than those in the CHB cohort regardless of LF stage.

CONCLUSION

Values of LF markers in CHB patients can differ from those in CHC patients even in the same LF stage. Difference in total amount of collagen fiber in CHB and CHC appears to be linked to the difference.

Cutoff Values of Acoustic Radiation Force Impulse Two-Location Measurements in Different Etiologies of Liver Fibrosis

BACKGROUND

Acoustic radiation force impulse (ARFI) imaging is a popular modality to measure liver fibrosis. ARFI selects optimal locations for measurement under imaging guiding. However, there are concerns on study locations and observers bias. To decrease the variations, ARFI at two locations was measured with standardized protocol. This study attempted to establish its cutoff values according to Metavir fibrosis score in different etiologies.

METHODS

A consecutive series of patients who received liver histology study were prospectively enrolled. All cases had hemogram, liver biochemistry, viral markers, and ARFI two-location measurements within 4 weeks of histology study. A standardized protocol was performed by single technologist. We excluded patients with alanine aminotransferase >5x upper limit normal.

RESULTS

Five hundred and ten patients that included 153 seronegative for both HBsAg and anti-HCV Non-B non-C (NBNC), 33 autoimmune liver diseases (AILD), 261 chronic hepatitis B (CHB), and 63 chronic hepatitis C (CHC) were enrolled. About 83% of NBNC patients had fat cell >5%. For diagnosis of liver cirrhosis, the area under receiver operating characteristic curve of NBNC, AILD, CHB, and CHC groups was 0.937, 0.929, 0.784, and 0.937; the cutoff values for mean ARFI were 1.788, 2.095, 1.455, and 1.710 m/s, respectively. The sensitivity and specificity are both over 0.818 for patients with nonalcoholic fatty liver diseases, CHC, and AILD, but the corresponding data are only 0.727-0.756 in CHB. The Fibrosis-4 Score is as good as ARFI on fibrosis assessment in NBNC.

CONCLUSION

The performance of ARFI two-location measurement is excellent in NBNC, AILD, and CHC, but is only satisfactory in CHB.

A gathering storm: HIV infection and nonalcoholic fatty liver disease in low and middle-income countries

: Despite the decreasing total incidence of liver-related deaths, liver disease remains one of the major non-AIDS causes of morbidity and mortality amongst people living with HIV, and a significant proportion of liver disease in these individuals can be attributed to nonalcoholic fatty liver disease (NAFLD). NAFLD in HIV infection is a growing problem in view of increasing life expectancy associated with the use of effective antiretroviral therapy (ART), wider uptake of ART and increasing rates of obesity in many Asian as well as western countries. The problem may be more pronounced in developing countries where there are limited resources available for mass screening and diagnosis of NAFLD. There is a small but growing body of literature examining NAFLD in the setting of HIV, with data from low and middle-income countries (LMICs) particularly lacking. Here, we review the cohort data on NAFLD in HIV, and discuss the risk factors, pathogenesis of hepatic steatosis, NAFLD and nonalcoholic steatohepatitis (NASH), diagnostic approaches and therapeutic options available for NAFLD in the setting of HIV, and the specific challenges of NAFLD in HIV for LMICs.

Evaluation of rat liver with ARFI elastography: In vivo and ex vivo study

OBJECTIVE

The aim of this study was to compare in vivo vs ex vivo liver stiffness in rats with acoustic radiation force impulse (ARFI) elastography using the histological findings as the gold standard.

METHODS

Eighteen male Wistar rats aged 16-18 months were divided into a control group (n = 6) and obese group (n = 12). Liver stiffness was measured with shear wave velocity (SWV) using the ARFI technique both in vivo and ex vivo. The degree of fibrosis, steatosis and liver inflammation was evaluated in the histological findings. Pearson's correlation coefficient was applied to relate the SWV values to the histological parameters.

RESULTS

The SWV values acquired in the ex vivo study were significantly lower than those obtained in vivo (P < 0.004). A significantly higher correlation value between the degree of liver fibrosis and the ARFI elastography assessment was observed in the ex vivo study (r = 0.706, P < 0.002), than the in vivo study (r = 0.623, P < 0.05).

CONCLUSION

Assessment of liver stiffness using ARFI elastography yielded a significant correlation between SWV and liver fibrosis in both the in vivo and ex vivo experiments. We consider that by minimising the influence of possible sources of artefact we could improve the accuracy of the measurements acquired with ARFI.

Diagnosis and management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western industrialised countries. The prevalence of NAFLD is increasing in parallel with the global rise in obesity and type 2 diabetes mellitus. NAFLD represents a spectrum of liver disease severity. NAFLD begins with accumulation of triacylglycerols in the liver (steatosis), and is defined by hepatic fatty infiltration amounting to greater than 5% by liver weight or the presence of over 5% of hepatocytes loaded with large fat vacuoles. In almost a quarter of affected individuals, steatosis progresses with the development of liver inflammation to non-alcoholic steatohepatitis (NASH). NASH is a potentially progressive liver condition and with ongoing liver injury and cell death can result in fibrosis. Progressive liver fibrosis may lead to the development of cirrhosis in a small proportion of patients. With the growing prevalence of NAFLD, there is an increasing need for a robust, accurate and non-invasive approach to diagnosing the different stages of this condition. This review will focus on (1) the biochemical tests and imaging techniques used to diagnose the different stages of NAFLD; and (2) a selection of the current management approaches focusing on lifestyle interventions and pharmacological therapies for NAFLD.

Elastography in the Diagnosis of Non-Alcoholic Fatty Liver Disease

Currently, there has been a progressive increase in prevalence of one of the most common diffuse chronic liver diseases ― non-alcoholic fatty liver disease (NAFLD). Assessment of the stages of liver fibrosis and steatosis is prognostically significant in diagnosis of NAFLD. Routine diagnostic methods are either not able to accurately assess the severity of fibrosis and steatosis (ultrasound, laboratory tests), or cannot be used as a simple screening tool (liver biopsy) due to such limitations as invasiveness, dependence on pathologist qualification, high cost, and limited region of interest. Over the last two decades, the great progress has been made in non-invasive visualization of pathological changes in liver diseases. In this review, we examined the diagnostic characteristics of the most widely used non-invasive imaging methods in clinical practice, available for quantitative determination of fat and fibrosis in the liver: transient elastography with controlled attenuation parameter (CAP), acoustic radiation force impulse (ARFI) and shear wave elastography (SWE). Comparing these methods and their limitations, we came to conclusion, that elastographic methods (slightly more ARFI and SWE) are able to verify the F3, F4 stages of fibrosis in NAFLD with high sensitivity and specificity (90%); however, they are less accurate for early stages. Elastographic techniques have moderate accuracy in identifying the degree of steatosis due to the lack of uniform standardized cut-off values of CAP.

Liver stiffness measurement by acoustic radiation forced impulse and transient elastography in patients with intrahepatic cholestasis

BACKGROUND

Transient elastography (TE) and acoustic radiation force impulse (ARFI) imaging enable a noninvasive assessment of liver stiffness measurement (LSM) and liver fibrosis/cirrhosis staging. However, their use in cholestatic diseases is still scarce.

AIM

The aim of this study was to evaluate the performance of TE and ARFI for the initial assessment of hepatic fibrosis in intrahepatic cholestatic (IHC) diseases and assess LSM changes after 3 months of specific therapy.

PATIENTS AND METHODS

This prospective study was carried out on 50 IHC patients. Assessment at baseline and after 3 months of LSM by TE and ARFI was performed.

RESULTS

Overall, 60% of the patients were women (36.5±9.2 years). IHC etiologies were 23 (46%) autoimmune hepatitis, eight (16%) primary sclerosing cholangitis, eight (16%) drug induced, and five (10%) primary biliary cirrhosis. TE could diagnose ≥F2, ≥F3, and F4 stages at cutoffs of at least 6.7, 9.4, and 14.0 kPa, sensitivity/specificity were 100/50% for ≥F2, 88.2/83% for ≥F3, and 90/100% for F4. Moreover, the sensitivity and specificity of ARFI were 93/50% for ≥F2 (cutoff: 1.53 m/s); 71/67% for ≥F3 (cutoff 1.77 m/s); and 90/100% for F4 (cutoff: 2.43 m/s).Follow-up showed a significant decrease in TE and ARFI values by 27 and 22.3% (P<0.001 and <0.001, respectively) and, accordingly, fibrosis stages decreased significantly by both TE and ARFI (P=0.002 and <0.001, respectively).

CONCLUSION

TE and ARFI represent noninvasive methods with adequate diagnostic performance for the assessment of fibrosis, and monitoring disease progression and treatment response in intrahepatic cholestasis.

Noninvasive Assessment of Liver Disease in Patients With Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is estimated to afflict approximately 1 billion individuals worldwide. In a subset of NAFLD patients, who have the progressive form of NAFLD termed nonalcoholic steatohepatitis (NASH), it can progress to advanced fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related morbidity and mortality. NASH is typically characterized by a specific pattern on liver histology, including steatosis, lobular inflammation, and ballooning with or without peri-sinusoidal fibrosis. Thus, key issues in NAFLD patients are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. Until now, liver biopsy has been the gold standard for identifying these 2 critical end points, but has well-known limitations, including invasiveness; rare but potentially life-threatening complications; poor acceptability; sampling variability; and cost. Furthermore, due to the epidemic proportion of individuals with NAFLD worldwide, liver biopsy evaluation is impractical, and noninvasive assessment for the diagnosis of NASH and fibrosis is needed. Although much of the work remains to be done in establishing cost-effective strategies for screening for NASH, advanced fibrosis, and cirrhosis, in this review, we summarize the current state of the noninvasive assessment of liver disease in NAFLD, and we provide an expert synthesis of how these noninvasive tools could be utilized in clinical practice. Finally, we also list the key areas of research priorities in this area to move forward clinical practice.

Noninvasive evaluation of nonalcoholic fatty liver disease: Current evidence and practice

With the increasing number of individuals with diabetes and obesity, nonalcoholic fatty liver disease (NAFLD) is becoming increasingly prevalent, affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden, and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD, including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.

Criteria to Determine Reliability of Noninvasive Assessment of Liver Fibrosis With Virtual Touch Quantification

BACKGROUND & AIMS

Virtual Touch Quantification (VTQ) evaluates liver fibrosis in patients with chronic liver diseases by measuring shear wave speed in the liver. We aimed to determine the reliability criteria of VTQ examination.

METHODS

We performed a prospective study of 1094 patients with chronic liver disease from November 2009 through October 2016 at Angers University Hospital, and between April 2010 and May 2015 at Bordeaux University Hospital, in France. All patients underwent liver biopsy analysis (reference standard), and VTQ examination was made by experienced operators on the same day, or no more than 3 months before or afterward. Advanced liver fibrosis was defined as fibrosis stage F ≥ 3 according to the scoring system of the Nonalcoholic Steatohepatitis Clinical Research Network, or fibrosis stage F ≥ 2 according to the Metavir scoring system. The diagnostic accuracy of VTQ in detection of advanced fibrosis or cirrhosis was assessed using the area under the receiver operating characteristic (AUROC) and the rate of correctly classified patients. Reliability criteria were defined from the intrinsic characteristics of VTQ examination, which were shown to influence the diagnostic accuracy.

RESULTS

VTQ identified patients with advanced fibrosis with an AUROC of 0.773 ± 0.014 and correctly classified 72.0% of patients using a diagnostic cut-off value of 1.37 m/s. VTQ identified patients with cirrhosis with an AUROC value of 0.839 ± 0.014 and correctly classified 78.4% of patients using a cut-off value of 1.87 m/s. The reliability of VTQ decreased with an increasing ratio of interquartile range/median (IQR/M) in patients with intermediate-high VTQ results. We defined 3 reliability categories for VTQ: unreliable (IQR/M ≥0.35 with VTQ result ≥1.37 m/s), reliable (IQR/M ≥0.35 with VTQ result <1.37 m/s or IQR/M 0.15-0.34), and very reliable (IQR/M <0.15). For advanced fibrosis, VTQ correctly classified 57.8% of patients in the unreliable group, 73.7% of patients in the reliable group, and 80.9% of patients in the very reliable group (P < .001); for cirrhosis, these values were 50.0%, 83.4%, and 92.6%, respectively (P < .001). Of the VTQ examinations made, 21.4% were unreliable, 55.0% were reliable, and 23.6% were very reliable. The skin-liver capsule distance was independently associated with an unreliable VTQ examination, which occurred in 52.7% of patients with a distance of 30 mm or more.

CONCLUSIONS

In a study to determine the reliability of VTQ findings, compared with results from biopsy analysis, we assigned VTQ examinations to 3 categories (unreliable, reliable, and very reliable). VTQ examinations with IQR/M ≥0.35 and ≥1.37 m/s had very low diagnostic accuracy. Our reliability criteria for liver fibrosis assessment with VTQ will help physicians to accurately evaluate the severity of chronic liver diseases and monitor their progression.

Advances and challenges in the management of advanced fibrosis in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common type of chronic liver disease worldwide. From the spectrum of NAFLD, it is nonalcoholic steatohepatitis (NASH) that predominantly predisposes patients to higher risk for development of cirrhosis and hepatocellular carcinoma. There is growing evidence that the risk of progression to cirrhosis and hepatocellular carcinoma is not uniform among all patients with NASH. In fact, NASH patients with increasing numbers of metabolic diseases such as diabetes, hypertension, visceral obesity and dyslipidemia are at a higher risk of mortality. Additionally, patients with higher stage of liver fibrosis are also at increased risk of mortality. In this context, NASH patients with fibrosis are in the most urgent need of treatment. Also, the first line of treatment for NASH is lifestyle modification with diet and exercise. Nevertheless, the efficacy of lifestyle modification is quite limited. Additionally, vitamin E and pioglitazone may be considered for subset of patients with NASH. There are various medications targeting one or more steps in the pathogenesis of NASH being developed. These drug regimens either alone or in combination, may provide potential treatment option for patients with NASH.

Liver ultrasound elastography for the evaluation of periportal fibrosis in schistosomiasis mansoni: A cross-sectional study

BACKGROUND

ARFI elastrography has been used as a noninvasive method to assess the severity of liver fibrosis in viral hepatitis, although with few studies in schistosomiasis mansoni. We aimed to evaluate the performance of point shear wave elastography (pSWE) for predicting significant periportal fibrosis (PPF) in schistosomotic patients and to determine its best cutoff point.

METHODOLOGY/PRINCIPAL FINDINGS

This cross-sectional study included 358 adult schistosomotic patients subjected to US and pSWE on the right lobe. Two hundred two patients (62.0%) were women, with a median age of 54 (ranging 18-92) years. The pSWE measurements were compared to the US patterns of PPF, as gold standard, according to the Niamey classification. The performance of pSWE was calculated as the area under the ROC curve (AUC). Patients were further classified into two groups: 86 patients with mild PPF and 272 patients with significant PPF. The median pSWE of the significant fibrosis group was higher (1.40 m/s) than that of mild fibrosis group (1.14 m/s, p<0.001). AUC was 0.719 with ≤1.11 m/s as the best cutoff value for excluding significant PPF. Sensitivity and negative predictive values were 80.5% and 40.5%, respectively. Whereas, for confirming significant PPF, the best cutoff value was >1.39 m/s, with specificity of 86.1% and positive predictive value of 92.0%.

CONCLUSIONS/SIGNIFICANCE

pSWE was able to differentiate significant from mild PPF, with better performance to predict significant PPF.

Wisteria floribunda agglutinin-positive Mac-2-binding protein and type 4 collagen 7S: useful markers for the diagnosis of significant fibrosis in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

The fibrosis stage of liver is associated with the long-term outcomes in patients with non-alcoholic fatty liver disease (NAFLD). However, significant fibrosis, defined as fibrosis stages 2-4, is associated with an elevated risk of progression to severe liver disease; there have been scant reports about diagnosing significant fibrosis. We compare the noninvasive method and aim to identify appropriate liver fibrosis markers for detecting significant fibrosis in NAFLD patients.

METHODS

We compared the usefulness of liver fibrosis markers (Wisteria floribunda agglutinin-positive Mac-2-binding protein [WFA⁺ -M2BP], type 4 collagen 7S, etc.), clinical scoring systems, and liver stiffness measurement obtained using vibration-controlled transient elastography and magnetic resonance imaging-based magnetic resonance elastography in the same individuals and identified the most appropriate noninvasive method for detecting significant fibrosis in 165 patients with liver biopsy-diagnosed NAFLD.

RESULTS

The area under the receiver operating characteristic curve based on the serum cutoff index values of WFA⁺ -M2BP/the serum levels of type IV collagen 7S for the diagnosis of significant fibrosis was 0.832 (95% confidence interval: 0.771-0.894)/0.837 (95% confidence interval: 0.778-0.898). "WFA⁺ -M2BP (cutoff index) ≥ 0.83 or type IV collagen 7S ≥ 5.2 ng/mL" showed a high sensitivity (91.4%) and negative predictive value (87.9%) for the diagnosis of significant fibrosis.

CONCLUSIONS

We showed that serum WFA⁺ -M2BP or type IV collagen 7S levels serve as useful independent markers for detecting significant fibrosis and that use of both WFA⁺ -M2BP and type IV collagen 7S together increased the sensitivity and negative predictive value for the diagnosis of liver fibrosis. These results need to be validated in larger populations from multiple clinical centers.