Controlled attenuation parameter for the detection of steatosis severity in chronic liver disease: a meta-analysis of diagnostic accuracy

The evaluation of non-alcoholic fatty liver disease in children with obesity with vibration-controlled transient elastography

INTRODUCTION

Parallel to the worldwide increase in obesity, the epidemic of chronic liver disease is increasing also in pediatric population. Our aim is to provide a different outlook on the current screening confusion in pediatric non-alcoholic fatty liver disease (NAFLD) with the non-invasive vibration-controlled transient elastography (VCTE) method.

MATERIALS AND METHODS

This single-center, cross-sectional, comparative study was performed at the tertiary center, included 95 patients with obesity and 116 controls, both groups were 9-18 years of ages. VCTE examinations performed in all patients. The cut-off values for controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were established by comparing the study and control groups.

RESULTS

The cut-off for CAP was determined as >236 dB/m when comparing the two groups. The AUC was 0.900 (95% CI, 0.851-0.937) and the diagnostic accuracy was 77.9% and 91.4% for sensitivity and specificity, respectively. The cut-off value for LSM >5 kPa was determined by comparison of the two groups. The AUC was 0.794 (95% CI, 0.733-0.846) and the diagnostic accuracies were 50.5% and 90.5% for sensitivity and specificity, respectively.

CONCLUSIONS

There is no benchmark method for screening pediatric NAFLD. However, VCTE is a promising method for screening pediatric NAFLD. It is accessible, repeatable and practical.

Methodology exploration and reproducibility evaluation of TAI and TSI for quantitative ultrasound assessment of hepatic steatosis

Background and aim

New quantitative ultrasound techniques can be used to quantify hepatic steatosis, including tissue attenuation imaging (TAI), tissue scatter -distribution imaging (TSI), and the hepatorenal index (HRI). However, the measurement norms and the effects of fasting on these measurements remain unclear. The present study performed a methodological exploration and investigated the reliability of these measurements.

Methods

In total, 103 participants were prospectively recruited for ultrasonography and magnetic resonance imaging (MRI) scans. For the TAI and TSI data, the upper (2 cm), middle (4 cm) and lower (6 cm) areas determined according to the depth of the region of interest from the liver capsule, were sampled three times. Correlation analyses were performed to compare the measurements of TAI, TSI, and HRI with the controlled attenuation parameter (CAP) or MRI-proton density fat fraction (MRI-PDFF). Intra- and inter-operator repeatability was assessed using intraclass correlation coefficients. The effects of fasting on these measurements were then compared.

Results

The TAI and TSI measurements obtained from the upper and middle depths exhibited stronger correlations with the CAP measurements than those obtained from the lower depth. Specifically, the mean TAI had a significant positive correlation with MRI-PDFF (r = 0.753, P < 0.0001). TAI and TSI measurements exhibited excellent intra- (0.933 and 0.925, respectively) and inter- (0.896 and 0.766, respectively) examiner reliability. However, the correlation between HRI and CAP measurements was only 0.281, with no significant correlation with MRI-PDFF, and intra- and inter-examiner reproducibility of 0.458 and 0.343, respectively. Fasting did not affect these measurements.

Conclusions

TAI and TSI measurements demonstrated good intra- and interobserver reliability and correlated well with CAP and MRI-PDFF measurements. However, in practice-based clinical applications, the sampling depth should be controlled within 2-4 cm of the hepatic capsule; no fasting is required before the examination.

ACR Appropriateness Criteria® Abnormal Liver Function Tests

Liver function tests are commonly obtained in symptomatic and asymptomatic patients. Various overlapping lab patterns can be seen due to derangement of hepatocytes and bile ducts function. Imaging tests are pursued to identify underlying etiology and guide management based on the lab results. Liver function tests may reveal mild, moderate, or severe hepatocellular predominance and can be seen in alcoholic and nonalcoholic liver disease, acute hepatitis, and acute liver injury due to other causes. Cholestatic pattern with elevated alkaline phosphatase with or without elevated γ-glutamyl transpeptidase can be seen with various causes of obstructive biliopathy. Acute or subacute cholestasis with conjugated or unconjugated hyperbilirubinemia can be seen due to prehepatic, intrahepatic, or posthepatic causes. We discuss the initial and complementary imaging modalities to be used in clinical scenarios presenting with abnormal liver function tests. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The Accuracy of Ultrasound Controlled Attenuation Parameter in Diagnosing Hepatic Fat Content

Purpose

The Controlled Attenuation Parameter (CAP score) is based on ultrasonic properties of retropropagated radiofrequency signals acquired by Fibroscan^TM (Echosens, Paris, France). Since ultrasound propagation is influenced by the presence of fat, CAP score was developed to quantify steatosis. The aim of this study was to delineate the accuracy of CAP in diagnosing hepatic steatosis, compared to the gold standard of liver biopsy.

Patients and Methods

A total of 150 patients underwent same-day liver biopsy and measurement of hepatic steatosis with Fibroscan. Only examinations with 10 satisfactory measurements, and an inter-quartile range of less than 30% of the median liver stiffness values were included for data analysis. Histological staging was then correlated with median values and Spearman correlation calculated. P values of <0.05 were considered statistically significant.

Results

For diagnosis of hepatic steatosis (HS), CAP could predict the steatosis S2 with AUROC 0.815 (95% CI 0.741-0.889), sensitivity (0.81) and specificity (0.73) when the optimal cut-off value was set at 288 dB/m. CAP detected histological grade S3 with AUROC 0.735 (95% CI 0.618-0.851), sensitivity (0.71) and specificity (0.74), with a cut-off value of 330 dB/m. The AUROC for steatosis grade S1 was 0.741 (95% CI 0.650-0.824), with a cut-off value of 263 dB/m with sensitivity 0.75 and specificity 0.70. Univariate analysis showed a correlation between CAP and diabetes (p 0.048).

Conclusion

The performance of CAP to diagnose steatosis severity decreases as steatosis progresses. CAP is associated with diabetes but not other clinical factors and parameters of the metabolic syndrome.

AST/ALT ratio, APRI, and FIB-4 compared to FibroScan for the assessment of liver fibrosis in patients with chronic hepatitis B in Bandar Abbas, Hormozgan, Iran

BACKGROUND

Chronic hepatitis B (CHB) is a significant risk factor for liver-related disorders. Hepatic fibrosis staging by liver biopsy in these patients can lead to complications. This study aimed to compare aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, AST to platelet ratio index (APRI), and fibrosis-4 (FIB-4) with FibroScan results for the evaluation of hepatic fibrosis in CHB patients.

METHODS

This cross-sectional study included patients with CHB referred to the outpatient clinics of Bandar Abbas, Hormozgan, Iran, in 2021. The age and sex of the participants were noted. FibroScan evaluation was done for all subjects. Moreover, AST, ALT, and platelet counts were measured in their blood samples within one month of the FibroScan evaluation.

RESULTS

Of the 267 CHB patients evaluated in the present study (mean age: 45.45 ± 18.16 years), 173 (64.8%) were male. According to FibroScan results, 65 CHB patients (24.3%) had F1, 53 (19.9%) F2, 38 (14.2%) F3, and 20 (7.5%) F4 liver fibrosis. There was a significant correlation between FibroScan results and the three indices of AST/ALT ratio, APRI, and FIB-4 (P < 0.001), with the strongest correlation between FibroScan results and APRI (r = 0.682). With an area under the receiver operating characteristic (AUROC) curve of 0.852 (95% confidence interval [CI] 0.807; 0.897, P < 0.001), APRI ≥ 0.527 had the best diagnostic accuracy (77.15%) for the detection of any grade of liver fibrosis. Although the AUROC curve of APRI and FIB-4 was similar (0.864) for distinguishing between F3/F4 and F0-F2 of liver fibrosis, FIB-4 had the best diagnostic accuracy (82.02%).

CONCLUSIONS

APRI can rule out 95.4% of F3/F4 of liver fibrosis and rule in any grade of liver fibrosis in CHB patients by 90.78%. Therefore, APRI appears to be the best substitute for FibroScan in the assessment of liver fibrosis in patients with CHB.

Non-alcoholic fatty liver and fibrosis is associated with cardiovascular structure and function in young adults

BACKGROUND

Non-alcoholic fatty liver disease shares many risk factors with other metabolic disorders. We sought to establish whether non-alcoholic fatty liver disease may be associated with cardiovascular health independently of other known risk factors.

METHODS

In this prospective, population-based cohort of young adults, controlled attenuation parameter-defined liver steatosis, transient elastography-defined liver fibrosis, echocardiography, carotid ultrasonography, and pulse wave analysis were assessed at age 24 years. We examined associations between liver and cardiovascular measures, with and without accounting for demographics, body mass index, alcohol, smoking, blood pressure, lipidemia, glycemia, and inflammation.

RESULTS

We included 2047 participants (mean age 24.4 y; 36.2% female): 212 (10.4%) had steatosis, whereas 38 (1.9%) had fibrosis. Steatosis was associated with cardiovascular measures after adjusting for demographics, but with more comprehensive adjustment, steatosis only remained associated with stroke index [β (95% CI) of -1.85 (-3.29, -0.41) mL/m2] and heart rate [2.17 (0.58, 3.75) beats/min]. Fibrosis was associated with several measures of cardiovascular structure and function after full adjustment for risk factors, including left ventricular mass index [2.46 (0.56, 4.37) g/m2.7], E/A ratio [0.32 (0.13, 0.50)], tricuspid annular plane systolic excursion [0.14 (0.01, 0.26) cm], carotid intima-media thickness [0.024 (0.008, 0.040) mm], pulse wave velocity [0.40 (0.06, 0.75) m/s], cardiac index [-0.23 (-0.41, -0.06) L/min⋅m2], and heart rate [-7.23 (-10.16, -4.29) beats/min].

CONCLUSIONS

Steatosis was not associated with measures of cardiovascular structure and function nor with subclinical atherosclerosis after adjusting for known cardiovascular risk factors. Fibrosis, however, was associated with several cardiovascular measures, including indicators of subclinical atherosclerosis, even after full adjustment. Further follow-up will help determine whether cardiovascular health worsens later with steatosis alone.

Ultrasound-based hepatic fat quantification: current status and future directions

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disease from fatty accumulation (steatosis), necro-inflammation though to fibrosis. It is of increasing global prevalence as a hepatic manifestation of the metabolic syndrome. Although accurate histopathology and magnetic resonance imaging techniques for hepatic fat quantification exist, these are limited by invasiveness and availability, respectively. Ultrasonography is potentially ideal for assessing and monitoring hepatic steatosis given the examination is rapid and readily available. Traditional ultrasound methods include qualitative B-mode for imaging markers, such as increased hepatic parenchymal echogenicity compared to adjacent renal cortex are commonplace; however, there is acknowledged significant interobserver variability and they are suboptimal for detecting mild steatosis. Recently quantitative ultrasound metrics have been investigated as biomarkers for hepatic steatosis. These methods rely on changes in backscatter, attenuation, and speed of sound differences encountered in a steatotic liver. Prospective studies using quantitative ultrasound parameters show good diagnostic performance even at low steatosis grades and in NAFLD. This review aims to define the clinical need for ultrasound-based assessments of liver steatosis, to describe briefly the physics that underpins the various techniques available, and to assess the evidence base for the effectiveness of the techniques that are available commercially from various ultrasound vendors.

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.

Controlled attenuation parameter-insulin resistance (CIR) score to predict non-alcoholic steatohepatitis

The diagnosis of non-alcoholic steatohepatitis (NASH) requires liver biopsy. Patients with NASH are at risk of progression to advanced fibrosis and hepatocellular carcinoma. A reliable non-invasive tool for the detection of NASH is needed. We aimed at developing a tool to diagnose NASH based on a predictive model including routine clinical and transient hepatic elastography (TE) data. All subjects undergoing elective cholecystectomy in our center were invited to participate, if alcohol intake was < 30 g/d for men and < 15 g/d for women. TE with controlled attenuation parameter (CAP) was obtained before surgery. A liver biopsy was taken during surgery. Multivariate logistic regression models to predict NASH were constructed with the first 100 patients, the elaboration group, and the results were validated in the next pre-planned 50 patients. Overall, 155 patients underwent liver biopsy. In the elaboration group, independent predictors of NASH were CAP value [adjusted OR (AOR) 1.024, 95% confidence interval (95% CI) 1.002-1.046, p = 0.030] and HOMA value (AOR 1.847, 95% CI 1.203-2.835, p < 0.001). An index derived from the logistic regression equation to identify NASH was designated as the CAP-insulin resistance (CIR) score. The area under the receiver operating characteristic curve (95%CI) of the CIR score was 0.93 (0.87-0.99). Positive (PPV) and negative predictive values (NPV) of the CIR score were 82% and 91%, respectively. In the validation set, PPV was 83% and NPV was 88%. In conclusion, the CIR score, a simple index based on CAP and HOMA, can reliably identify patients with and without NASH.

Antenatal FibroScan® assessment for metabolic-associated fatty liver in pregnant women at risk of gestational diabetes from a multiethnic population: a pilot study

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a leading cause of chronic liver disease with increasingly recognised associations with gestational diabetes (GDM), including within the antenatal period.

AIMS

To assess the relationship between MAFLD in pregnancy and development of GDM.

METHODS

Fifty pregnant women were enrolled before 24 weeks gestation from a multiethnic obstetrics service in Sydney, Australia. Two FibroScan® assessments were performed, one prior to 24 weeks and one after 30 weeks gestation, to assess hepatic steatosis and stiffness. A control attenuated parameter (CAP) score ≥ 233.5 dB/m signified MAFLD. GDM was determined by an antenatal 75-g oral glucose tolerance testing.

RESULTS

Six (12%) women had evidence of FibroScan®-detected MAFLD in early pregnancy, while none had abnormal hepatic stiffness. Sixteen (32%) women developed GDM. No significant difference was observed in GDM rates (50% vs 29.5%; P = 0.37) between those with MAFLD in early pregnancy and those without. At the second scan (completed by 34 women), those who developed GDM had a lower observed mean increase in CAP scores (11.1 ± 23.3 dB/m vs -14.9 ± 26.0 dB/m; P = 0.004) and lower maternal weight gain (0.6 ± 0.2 kg/week vs 0.4 ± 0.2 kg/week; P = 0.04).

CONCLUSIONS

There was no statistically significant association between FibroScan®-detected MAFLD in early pregnancy and subsequent development of GDM in this pilot study. Maternal weight gain may be associated with changes in the CAP scores, which reflect steatosis, during pregnancy.

Comparative Study of Raw Ultrasound Data Representations in Deep Learning to Classify Hepatic Steatosis

Adiposity accumulation in the liver is an early-stage indicator of non-alcoholic fatty liver disease. Analysis of ultrasound (US) backscatter echoes from liver parenchyma with deep learning (DL) may offer an affordable alternative for hepatic steatosis staging. The aim of this work was to compare DL classification scores for liver steatosis using different data representations constructed from raw US data. Steatosis in N = 31 patients with confirmed or suspected non-alcoholic fatty liver disease was stratified based on fat-fraction cutoff values using magnetic resonance imaging as a reference standard. US radiofrequency (RF) frames (raw data) and clinical B-mode images were acquired. Intermediate image formation stages were modeled from RF data. Power spectrum representations and phase representations were also calculated. Co-registered patches were used to independently train 1-, 2- and 3-D convolutional neural networks (CNNs), and classifications scores were compared with cross-validation. There were 67,800 patches available for 2-D/3-D classification and 1,830,600 patches for 1-D classification. The results were also compared with radiologist B-mode annotations and quantitative ultrasound (QUS) metrics. Patch classification scores (area under the receiver operating characteristic curve [AUROC]) revealed significant reductions along successive stages of the image formation process (p &lt; 0.001). Patient AUROCs were 0.994 for RF data and 0.938 for clinical B-mode images. For all image formation stages, 2-D CNNs revealed higher patch and patient AUROCs than 1-D CNNs. CNNs trained with power spectrum representations converged faster than those trained with RF data. Phase information, which is usually discarded in the image formation process, provided a patient AUROC of 0.988. DL models trained with RF and power spectrum data (AUROC = 0.998) provided higher scores than conventional QUS metrics and multiparametric combinations thereof (AUROC = 0.986). Radiologist annotations indicated lower hepatic steatosis classification accuracies (Acc = 0.914) with respect to magnetic resonance imaging proton density fat fraction that DL models (Acc = 0.989). Access to raw ultrasound data combined with artificial intelligence techniques may offer superior opportunities for quantitative tissue diagnostics than conventional sonographic images.

Liver stiffness and steatosis in preeclampsia as shown by transient elastography-a prospective cohort study

BACKGROUND

Preeclampsia is a multisystem disorder and the leading cause of severe morbidity and death in pregnancy. Liver involvement in preeclampsia ranges from elevated liver enzyme levels to hepatic infarction or rupture. Endothelial dysfunction leads to changes in blood flow and congestion and may be involved in the pathophysiology of preeclampsia. Changes in splanchnic blood flow and portal congestion can lead to altered liver stiffness. Transient elastography is a noninvasive, ultrasound-based technique that measures organ stiffness and steatosis and is therefore widely used in clinical hepatology. Previous studies reported elevated liver stiffness and liver steatosis, as measured by transient elastography, in women with preeclampsia.

OBJECTIVE

This study followed changes in liver stiffness and steatosis, as measured by transient elastography, from the antepartum period to 1-week postpartum among women with preeclampsia compared with healthy controls and evaluated the association between preeclampsia severity and transient elastography results.

STUDY DESIGN

This prospective cohort study was conducted from 2017 through 2021. The study group comprised women with preeclampsia, and the control group comprised healthy pregnant women hospitalized for other reasons. All the participants underwent transient elastography either on diagnosis of preeclampsia (study group) or on hospital admission (control group) and again in the postpartum period. Liver stiffness measurements are expressed in kilopascals (kPa) in the range of 2.5 to 75 kPa, and liver steatosis is expressed by controlled attenuation parameter in the range of 100 to 400 dB/m.

RESULTS

The study group comprised 36 women and the control group 37. Liver stiffness scores were significantly elevated in the study when compared with the control group, both in the antepartum period (P<.001) and the postpartum period (P=.025). Liver stiffness scores decreased significantly after delivery in the study and control groups (P<.001 and P=.002, respectively). Liver steatosis scores were higher in the study group than in the control group both in the antepartum and postpartum periods (P<.001 and P<.02, respectively). In the multivariable analysis, the diagnosis of preeclampsia correlated with higher antepartum liver stiffness scores (P=.005). For the study group, postpartum liver stiffness and liver steatosis scores were increased among those with vs those without severe features of preeclampsia (P=.03 and P=.04, respectively) CONCLUSION: Reductions in liver stiffness and steatosis from the antepartum to the postpartum period were documented in both the preeclampsia and control groups. However, both these measures were higher in the preeclampsia group and correlated with preeclampsia severity. Larger studies may be able to determine whether transient elastography can predict the severity of preeclampsia or other related metabolic conditions that correlate with chronic hypertension.

A new nutraceutical (Livogen Plus®) improves liver steatosis in adults with non-alcoholic fatty liver disease

Background

Currently, there is no approved medication for non-alcoholic fatty liver disease management. Pre-clinical and clinical studies showed that several bioactive molecules in plants or foods (i.e., curcumin complex, bergamot polyphenol fraction, artichoke leaf extract, black seed oil, concentrate fish oil, picroliv root, glutathione, S-adenosyl-l-methionine and other natural ingredients) have been associated with improved fatty liver disease. Starting from these evidences, our purpose was to evaluate the effects of a novel combination of abovementioned nutraceuticals as a treatment for adults with fatty liver disease.

Methods

A total of 140 participants with liver steatosis were enrolled in a randomized, double-blind, placebo controlled clinical trial. The intervention group received six softgel capsules daily of a nutraceutical (namely Livogen Plus®) containing a combination of natural bioactive components for 12 weeks. The control group received six softgel capsules daily of a placebo containing maltodextrin for 12 weeks. The primary outcome measure was the change in liver fat content (CAP score). CAP score, by transient elastography, serum glucose, lipids, transaminases, and cytokines were measured at baseline and after intervention.

Results

After adjustment for confounding variables (i.e., CAP score and triglyceride at baseline, and changes of serum γGT, and vegetable and animal proteins, cholesterol intake at the follow-up), we found a greater CAP score reduction in the nutraceutical group rather than placebo (− 34 ± 5 dB/m vs. − 20 ± 5 dB/m, respectively; p = 0.045). The CAP score reduction (%) was even greater in those with aged 60 or less, low baseline HDL-C, AST reduction as well as in men.

Conclusion

Our results showed that a new combination of bioactive molecules as nutraceutical was safe and effective in reducing liver fat content over 12 weeks in individuals with hepatic steatosis.

Trial registration ISRCTN, ISRCTN70887063. Registered 03 August 2021—retrospectively registered, https://doi.org/10.1186/ISRCTN70887063

Liver Ultrasound Attenuation: An Ultrasound Attenuation Index for Liver Steatosis Assessment

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the most widespread chronic liver disease type in the Western countries. Ultrasound (US) is used for NAFLD and hepatic steatosis (HS) grading. The most popular US method for NAFLD assessment is the hepatorenal index (HRI), but because of its limitations, other noninvasive methods have been developed. The Resona 7 US system has recently incorporated an US attenuation-related quantitative feature, liver ultrasound attenuation (LiSA), for HS estimation. The purpose of this study is to compare LiSA's and HRI's performance on NAFLD assessment.

METHODS

A total of 159 NAFLD patients having a magnetic resonance imaging-proton density fat fraction (MRI-PDFF) examination were examined by 2 radiologists, who performed LiSA and HRI measurements in the liver. Correlation of LiSA's and HRI's measurements with MRI-PDFF values was calculated through Pearson correlation coefficient (PCC). To further investigate the performance of LiSA and HRI, optimum cutoffs, provided by the literature, were used to correspond HS grades to MRI-PDFF results. Moreover, a receiver operating characteristic (ROC) analysis on LiSA measurements and steatosis grades was performed.

RESULTS

Magnetic resonance imaging-PDFF was better correlated with LiSA (PCC = 0.80) than HRI (PCC = 0.67). Receiver operating characteristic analysis showed better performance range for LiSA (77.8%-91.8%) than for HRI (72.8%-85.4%) on all HS grades for all studies used for corresponding MRI-PDFF values to HS grades.

CONCLUSIONS

The results indicate that LiSA is more accurate than HRI in HS differentiation and can lead to more accurate grading of HS on NAFLD patients.

Non-alcoholic fatty liver disease (NAFLD): a review of pathophysiology, clinical management and effects of weight loss

Given the increasing prevalence of diabetes and obesity worldwide, the deleterious effects of non-alcoholic fatty liver disease (NAFLD) are becoming a growing challenge for public health. NAFLD is the most common chronic liver disease in the Western world. NAFLD is closely associated with metabolic disorders, including central obesity, dyslipidaemia, hypertension, hyperglycaemia and persistent abnormalities of liver function tests.In general NAFLD is a common denominer for a broad spectrum of damage to the liver, which can be due to hepatocyte injury, inflammatory processes and fibrosis. This is normally seen on liver biopsy and can range from milder forms (steatosis) to the more severe forms (non-alcoholic steatohepatitis (NASH), advanced fibrosis, cirrhosis and liver failure). In these patients, advanced fibrosis is the major predictor of morbidity and liver-related mortality, and an accurate diagnosis of NASH and NAFLD is mandatory. Histologic evaluation with liver biopsy remains the gold standard to diagnose NAFLD. Diagnosis of NAFLD is defined as presence of hepatic steatosis, ballooning and lobular inflammation with or without fibrosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. Dietary recommendations and lifestyle interventions, weight loss, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established with promising results but are difficult to maintain. Pioglitazone and vitamin E are recommended by guidelines in selected patients. This review gives an overview of NAFLD and its treatment options.

Nicotinamide supplementation in diabetic nonalcoholic fatty liver disease patients: randomized controlled trial

Background:

Nicotinamide has been reported to protect against liver steatosis and metabolic imbalances in nonalcoholic fatty liver disease (NAFLD) in animal models.

Objectives:

The objective was to investigate the efficacy and safety of nicotinamide supplementation in diabetic NAFLD patients.

Design:

This is a prospective randomized controlled open label study.

Methods:

Seventy diabetic NAFLD patients were randomly assigned either to the nicotinamide group (n = 35) who received nicotinamide 1000 mg once daily for 12 weeks in addition to their antidiabetic therapy or the control group (n = 35) who received their antidiabetic therapy only. The primary outcome was improvement in steatosis score, while secondary outcomes included assessment of liver stiffness, liver enzymes, lipid profile, insulin resistance, serum malondialdehyde, serum adiponectin, and patients’ quality of life (QOL).

Results:

Only 61 patients completed the study; 31 in the nicotinamide group and 30 in the control group. Comparisons between groups and within groups revealed nonsignificant changes in steatosis and fibrosis scores. However, significant reduction was observed in liver enzymes with a median decrease in alanine transaminase of 26.6% versus 0.74% in nicotinamide and control groups, respectively. After 12 weeks of treatment, the nicotinamide group showed significantly lower levels of low-density lipoprotein cholesterol (p value = 0.004), total cholesterol (p value = 0.006), and insulin resistance marker (p value = 0.005) compared with control. Serum triglycerides, malondialdehyde, and adiponectin levels were all comparable between the two groups. Regarding QOL, a significant improvement was detected in the total scores and the activity and fatigue domains scores.

Conclusion:

Nicotinamide at a dose of 1000 mg daily was tolerable, improved metabolic abnormalities and QOL of diabetic NAFLD patients with no effect on liver fibrosis or steatosis.

Trial Registration:

The study was registered at clinicaltrials.gov and given the ID number: ‘NCT03850886’. https://clinicaltrials.gov/ct2/show/NCT03850886.

A prospective cohort study of the use of the fatty liver index and Fibroscan to determine the prevalence of fatty liver disease in an Irish population

OBJECTIVES

Rates of nonalcoholic fatty liver disease (NAFLD) are increasing worldwide. The fatty liver index (FLI) is a noninvasive predictor of NAFLD. This prospective cohort study used the FLI to estimate the prevalence of NAFLD in patients attending an Irish Acute Medical Unit (AMU), and assessed the degree of fibrosis in this group using Fibroscan.

METHODS

Patients attending the AMU over a 3-month period were invited to participate. Patients with excess alcohol consumption or pre-existing liver disease were excluded. Using established FLI cut-offs, 414 participants were grouped into low (FLI ≤ 30), medium (30 < FLI ≤ 60) and high (FLI > 60) risk of NAFLD. High-risk patients were offered review including liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) score.

RESULTS

A total of 134 patients were at low-risk, 96 at medium-risk and 184 at high-risk of NAFLD. Male sex (P < 0.0001) and increasing age (P < 0.0001) were associated with higher risk. Of the 120 high-risk patients who attended follow up, 13 participants had LSM > 7 kPa. Higher FLI scores were associated with higher CAP scores (P < 0.0001) but did not predict higher LSMs. Fasting glucose and HbA1c were found to be associated with higher LSM.

CONCLUSION

About 44.4% of patients presenting to the AMU were at high risk of NAFLD according to the FLI. Only 10.8% of the high-risk group, and 3% of all those recruited had a LSM > 7 kPa suggesting development of fibrosis.

Quantification of Liver Fat Content with Ultrasound: A WFUMB Position Paper

New ultrasound methods that can be used to quantitatively assess liver fat content have recently been developed. These quantitative ultrasound (QUS) methods are based on the analysis of radiofrequency echoes detected by the transducer, allowing calculation of parameters for quantifying the fat in the liver. In this position paper, after a section dedicated to the importance of quantifying liver steatosis in patients with non-alcoholic fatty liver disease and another section dedicated to the assessment of liver fat with magnetic resonance, the current clinical studies performed using QUS are summarized. These new methods include spectral-based techniques and techniques based on envelope statistics. The spectral-based techniques that have been used in clinical studies are those estimating the attenuation coefficient and those estimating the backscatter coefficient. Clinical studies that have used tools based on the envelope statistics of the backscattered ultrasound are those performed by using the acoustic structure quantification or other parameters derived from it, such as the normalized local variance, and that performed by estimating the speed of sound. Experts' opinions are reported.

Non-Alcoholic Fatty Liver Disease and Its Association With Diabetes Mellitus

There is a bidirectional relationship between non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). The liver has a vital role in the pathophysiology of both diseases as it leads to the development of insulin resistance (IR), which in turn results in NAFLD and T2DM. It has been shown that T2DM increases the risk of NAFLD progression. Furthermore, the presence of NAFLD raises the probability of T2DM complications, which explains the increased rates of NAFLD screening in patients with T2DM. In addition, there are common management options for the two diseases. Lifestyle changes can play a role in the initial management of both diseases. Medications that are used to treat T2DM are also used in the management of NAFLD, such as metformin, thiazolidinediones (TZD), glucagon-like peptide-1 (GLP-1) analogues, and dipeptidyl peptidase-4 (DPP4) inhibitors. Bariatric surgery is often used as a last resort and has shown promising results. Lifestyle interventions with diet and exercise are important postoperatively to maintain the weight loss. There are many novel treatments that are being investigated for the treatment of NAFLD, targeting multiple pathophysiologic pathways. This review aims to shed some light on the intricate relationship between NAFLD and T2DM and how IR links both diseases. We also try to raise awareness among clinicians about this relationship and how the presence of one disease should raise a high index of suspicion for the existence of the other.

Non-alcoholic Steatohepatitis Pathogenesis, Diagnosis, and Treatment

There has been a rise in the prevalence of non-alcohol fatty liver disease (NAFLD) due to the popularity of western diets and sedentary lifestyles. One quarter of NAFLD patients is diagnosed with non-alcoholic steatohepatitis (NASH), with histological evidence not only of fat accumulation in hepatocytes but also of liver cell injury and death due to long-term inflammation. Severe NASH patients have increased risks of cirrhosis and liver cancer. In this review, we discuss the pathogenesis and current methods of diagnosis for NASH, and current status of drug development for this life-threatening liver disease.

Noninvasive Estimation of Hepatic Steatosis by Controlled Attenuation Parameter in Living Donor Liver Transplant

OBJECTIVES

Estimation of liver fat among living donor candidates is necessary before living donor liver transplant. This study aimed to investigate the usefulness of the controlled attenuation parameter compared with liver biopsy for pretransplant estimation of hepatic steatosis in living liver donors.

MATERIALS AND METHODS

In this retrospective study, we included all individuals who underwent transient elastography with controlled attenuation parameter and ultrasonography-guided liver biopsy as a part of donor evaluations before living donor liver transplant. Clinical and laboratory data of living donor candidates were reviewed and collected.

RESULTS

Of 49 donor candidates included in this study, 21 (42.9%) had different degrees of hepatic macrosteatosis. Of the 21 donor candidates who had hepatic steatosis in liver biopsy, 13 individuals were diagnosed to have steatosis in transient elastography. Of the 28 donor candidates without hepatic steatosis in liver biopsy, 26 individuals showed no steatosis in transient elastography (odds ratio: 21.12; 95% CI, 3.91- 114.08; P < .001). Controlled attenuation parameter was useful in discriminating presence (P = .001) and grade of hepatic steatosis (P = .009) compared with liver biopsy with good sensitivity and specificity.

CONCLUSIONS

The controlled attenuation parameter is a noninvasive method for detection of hepatic steatosis in living donor candidates and can be used as an adjunct to liver biopsy for screening of living donor candidates before liver transplant.

Diagnostic accuracy of ultrasound-guided attenuation parameter as a noninvasive test for steatosis in non-alcoholic fatty liver disease

The purpose of this study was to evaluate the diagnostic accuracy of the ultrasound-guided attenuation parameter (UGAP) using the LOGEQ E10 for hepatic steatosis in non-alcoholic fatty liver disease (NAFLD) patients and directly compare UGAP with attenuation imaging (ATI) and controlled attenuation parameter (CAP). We prospectively analyzed 105 consecutive patients with NAFLD who underwent UGAP, ATI, CAP, and liver biopsy on the same day between October 2019 and April 2021. The diagnostic ability of the UGAP-determined attenuation coefficient (AC) was evaluated using receiver operating characteristic (ROC) curve analysis, and its correlation with ATI-determined AC values or CAP values was investigated. The success rate of UGAP was 100%. The median IQR/med obtained by UGAP was 4.0%, which was lower than that of ATI and CAP (P < 0.0001). The median ACs obtained by UGAP for grades S0 (control), S1, S2, and S3 were 0.590, 0.670, 0.750, and 0.845 dB/cm/MHz, respectively, demonstrating a stepwise increase with increasing hepatic steatosis severity (P < 0.0001). The areas under the ROC curve of UGAP for identifying ≥ S1, ≥ S2, and S3 were 0.890, 0.906, and 0.912, respectively, which were significantly better than the results obtained with CAP for identifying S3. Furthermore, the correlation coefficient between UGAP-AC and ATI-AC values was 0.803 (P < 0.0001), indicating a strong relationship. Our results indicate that UGAP has high diagnostic accuracy for detecting and grading hepatic steatosis in patients with NAFLD.

Steatosis grading consistency between controlled attenuation parameter and MRI-PDFF in monitoring metabolic associated fatty liver disease

Background

The consistency in steatosis grading between magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) and controlled attenuation parameter (CAP) before and after treatment remains unclear. This study aimed to compare the diagnostic accuracy of steatosis grading between MRI-PDFF and CAP using liver biopsy as standard and to evaluate the value of monitoring changes in steatosis grading with CAP during follow-up utilizing MRI-PDFF as a reference.

Methods

Consecutive patients from a biopsy cohort and a randomized controlled trial were included in this study and classified into 3 groups (the biopsy, orlistat treatment, and routine treatment subgroups). Hepatic steatosis was measured via MRI-PDFF and CAP at baseline and at the 6th month; the accuracy and cutoffs were assessed in the liver biopsy cohort at baseline.

Results

A total of 209 consecutive patients were enrolled. MRI-PDFF and CAP showed comparable diagnostic accuracy for detecting pathological steatosis [⩾S1, area under the receiver operating characteristic curve (AUC) = 0.984 and 0.972, respectively]; in contrast, CAP presented significantly lower AUCs in grades S2-3 and S3 (0.820 and 0.815, respectively). The CAP values correlated well with the MRI-PDFF values at baseline and at the 6th month (r = 0.809 and 0.762, respectively, both p < 0.001), whereas a moderate correlation in their changes (r = 0.612 and 0.524 for moderate-severe and mild steatosis, respectively; both p < 0.001) was observed. The AUC of CAP change was obtained to predict MRI-PDFF changes of ⩾5% and ⩾10% (0.685 and 0.704, p < 0.001 and p = 0.001, respectively). The diagnostic agreement of steatosis grade changes between MRI-PDFF and CAP was weak (κ = 0.181, p = 0.001).

Conclusions

CAP has decreased value for the initial screening of moderate-severe steatosis and is limited in monitoring changes in steatosis during treatment. The confirmation of steatosis grading with MRI-PDFF remains necessary.

Effect of skin-capsular distance on controlled attenuation parameter for diagnosing liver steatosis in patients with nonalcoholic fatty liver disease

The effect of the skin-capsular distance (SCD) on the controlled attenuation parameter (CAP) for diagnosis of liver steatosis in patients with nonalcoholic fatty liver disease (NAFLD) remains unclear. The SCD was measured using B-mode ultrasound, and the CAP was measured using the M probe of FibroScan®. According to the indications of the M probe, 113 patients with an SCD of ≤ 25 mm were included in the present study. The association between the SCD and CAP was investigated, and the diagnostic performance of the SCD-adjusted CAP was tested. The SCD showed the most significant positive correlation with the CAP (ρ = 0.329, p < 0.001). In the multiple regression analysis, the SCD and serum albumin concentration were associated with the CAP, independent of pathological liver steatosis. According to the multivariate analysis, two different formulas were developed to obtain the adjusted CAP using the SCD and serum albumin concentration as follows: adjusted CAP (dB/m) = CAP - (5.26 × SCD) and adjusted CAP (dB/m) = CAP - (5.35 × SCD) - (25.77 × serum albumin concentration). The area under the receiver operating characteristic curve for diagnosis of a steatosis score ≥ 2 of adjusted CAP was 0.678 and 0.684 respectively, which were significantly greater than the original CAP (0.621: p = 0.030 and p = 0.024). The SCD is associated with the CAP independent of liver steatosis. Adjustment of the CAP using the SCD improves the diagnostic performance of the CAP in NAFLD.

Controlled attenuation parameter measured using transient elastography for the noninvasive assessment of macrovesicular steatosis in potential living liver donors

PURPOSE

This study aimed to determine the diagnostic performance of the controlled attenuation parameter (CAP) measured using transient elastography (TE) for assessing macrovesicular steatosis (MaS) in potential living liver donors using same-day biopsy as a reference standard.

METHODS

This retrospective study included 204 living liver donor candidates who underwent TE and liver biopsy on the same day between July 2013 and June 2014. The histologic degree of MaS was determined. The area under the receiver operating characteristic curve (AUROC) was used to evaluate the performance of CAP for diagnosing MaS of >10%, and the optimal cutoff value was identified using the maximal Youden index.

RESULTS

Based on liver biopsy, 185 subjects had MaS of ≤10% and 19 had MaS of >10%. The CAP value was significantly correlated with the percentage of MaS on liver biopsy (r=0.635, P<0.001), and the median CAP value was significantly higher in subjects with MaS of >10% than in those with MaS of ≤10% (300 dB/m vs. 209 dB/m, P<0.001). The AUROC for diagnosing MaS of >10% by CAP was 0.938 (95% confidence interval, 0.896 to 0.967), and a CAP of >259 dB/m yielded a sensitivity of 84.2% and a specificity of 92.4%.

CONCLUSION

The CAP measured using TE was significantly correlated with MaS and accurately detected substantial MaS in potential living liver donors. The CAP is a promising tool for the noninvasive diagnosis of MaS and may be used to screen unsuitable living liver donor candidates.

Validating controlled attenuation parameter in the assessment of hepatic steatosis in living liver donors

INTRODUCTION

Hepatic steatosis (HS) negatively impacts transplant outcomes in living liver donors. To date, liver biopsy is preferred for HS evaluation. This study aims to evaluate the measurement of controlled attenuation parameter (CAP) as a diagnostic tool of HS in living liver donors.

METHODS

Candidates recruited to this study, conducted from April 2016 to February 2020, were potential donors who had undergone transient elastography using Fibroscan® and CAP measurements at liver segments VI and VII, followed by liver biopsy. The HS grades from liver biopsy were classified as S0 (<5%), S1 (5-33%), S2 (33-66%), and S3 (>66%). For CAP, they were S0 (≤218dB/m), S1 (218-249dB/m)), S2 (250-305dB/m)), and S3 (>305dB/m)). The CAP measurements were compared with the liver biopsy results.

RESULTS

Of the 150 potential donors [male, 73.3%; mean age, 30.0±7.0 years; body mass index (BMI), 24.7±3.5kg/m2], 92 (61.3%) had no or mild HS, while 58 (38.7%) and 10% had moderate to severe HS based on CAP and liver biopsy, respectively. Subjects with moderate to severe HS per CAP were mostly males (0.014), and had higher BMI (p = .006), alanine aminotransferase (ALT) (.001), gamma-glutamyl transferase (.026), and high-density lipoprotein (.008). On multivariate analysis, high ALT (OR, 1.051; 95% CI, 1.016-1.087; p = .004) was a predictor of significant HS. The sensitivity, specificity, positive and negative predictive values of CAP to detect significant HS were 93.3%, 67.4, 24.1%, and 98.9%, respectively.

CONCLUSION

The high sensitivity and negative predictive values of CAP make it a good screening test to exclude significant HS in potential living liver donors which, in turn, can help avoid unnecessary liver biopsies.

Are Noninvasive Methods Comparable to Liver Biopsy in Postoperative Patients After Roux-en-Y Gastric Bypass?

INTRODUCTION

Transient tissue elastography (TTE) may estimate the degree of hepatic fibrosis in patients with obesity, but the method has restrictions that are mainly related to patients' BMI.

PURPOSE

To compare the results of the evaluation of hepatic fibrosis by biochemical methods and TTE with those determined by liver biopsy in patients after RYGB.

METHODS

This was a cross-sectional study involving patient data, TTE, and liver biopsy 1 year after RYGB.

RESULTS

Of the 94 selected patients, 33 underwent TTE and liver biopsy. The average weight of patients was 84.4 ± 15.4 kg. The mean APRI was 0.2 ± 0.1, and 36 patients (97.3%) were classified as F0-F1. The average NFS was - 2.0 ± 1.0, with 25 patients (67%) classified as F0-F1 and 12 patients (32.4%) classified as F2. The agreement rate between Fibroscan and liver biopsy was 80.0%. Histological analysis revealed regression of inflammatory changes in all patients: 26 patients (72.2%) had some degree of non-alcoholic steatohepatitis (NAS ≥ 5), and after surgery, no patient presented inflammation upon biopsy. Nine patients (24.3%) had fibrosis at surgery, and only two (5.4%) still had fibrosis 1 year later (p < 0.008).

CONCLUSIONS

The use of APRI and Fibroscan is promising, but more studies are needed to evaluate patients with an advanced degree of NAFLD and confirm the entire spectrum of the disease.

Establishing Reliability Criteria for Liver ElastPQ Shear Wave Elastography (ElastPQ-SWE): Comparison Between 10, 5 and 3 Measurements

PURPOSE

 ElastPQ is a new elastography technique for non-invasive liver fibrosis staging. However, it does not have validated reliability criteria. We tested the reliability of a different number of measurements in patients with chronic liver disease and explored whether the application of quality criteria improves the diagnostic performance.

MATERIALS AND METHODS

 All patients underwent liver stiffness assessment (LSM) with ElastPQ and Fibroscan (F-TE). The mean, median, standard deviation (SD) and interquartile range (IQR) of 10, 5 and 3 measurements were retrospectively collected for each patient and compared to each other. Liver histology was available in a subset of patients.

RESULTS

 Overall, 400 patients met the inclusion criteria. Non-alcoholic fatty liver disease (NAFLD) was the most represented etiology (75 %), followed by primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH). The correlation of medians was significantly better between 10 and 5 measurements than between 10 and 3. The difference of medians was significant only in the comparison between 10 and 3 measurements. The correlation between ElastPQ and F-TE was equally good for 10 and 5 measurements and significantly improved after an IQR/median ≤ 30 % was applied. The diagnostic performance of ElastPQ was better with the median value of 10 and 5 measurements and improved if LSM values were obtained with IQR/M ≤ 30 %.

CONCLUSION

 The median value of 5 valid LSMs suffices for the reliable estimation of liver stiffness using ElastPQ. The quality criterion of IQR/M ≤ 30 % should also be followed when using this technique.

The prevalence of metabolic associated fatty liver detected by FibroScan® in women with gestational diabetes in a multiethnic population

AIMS

Metabolic associated fatty liver disease (MAFLD) is a leading cause of chronic liver disease and has been increasingly associated with gestational diabetes (GDM). This study aimed to assess the prevalence of MAFLD in women with GDM in the antenatal period.

METHODS

108 pregnant women with GDM diagnosed on a 75-gram oral glucose tolerance test were enrolled from a multiethnic cohort attending a large obstetrics clinic in Sydney, Australia and had a single FibroScan® assessment after 24 weeks gestation to assess for hepatic steatosis and fibrosis. A control attenuated parameter (CAP) cut-off score of ≥ 233.5 dB/m was chosen to signify presence of hepatic steatosis which indicates MAFLD. Obstetric, anthropometric and metabolic measures were analysed.

RESULTS

29 (26.9%) women had evidence of FibroScan®-detected MAFLD, whilst none had evidence of hepatic fibrosis. Increased maternal BMI (aOR 1.12, 95% CI: 1.04-1.20) was associated with the finding of MAFLD in this cohort.

CONCLUSIONS

We found a significant antenatal prevalence of FibroScan®-detected MAFLD in this cohort of multiethnic women with GDM. FibroScan® is a safe and rapid assessment tool which may have a role in screening for MAFLD in pregnancy in appropriate at-risk women.

Controlled Attenuation Parameter for Quantification of Steatosis: Which Cut-Offs to Use?

Chronic liver diseases (CLDs) are a public health problem, even if frequently they are underdiagnosed. Hepatic steatosis (HS), encountered not only in nonalcoholic fatty liver disease (NAFLD) but also in chronic viral hepatitis, alcoholic liver disease, etc., plays an important role in fibrosis progression, regardless of CLD etiology; thus, detection and quantification of HS are imperative. Controlled attenuation parameter (CAP) feature, implemented in the FibroScan® device, measures the attenuation of the US beam as it passes through the liver. It is a noninvasive technique, feasible and well accepted by patients, with lower costs than other diagnostic techniques, with acceptable accuracy for HS quantification. Multiple studies have been published regarding CAP performance to quantify steatosis, but due to the heterogeneity of CLD etiologies, of steatosis prevalence, etc., it had widely variable calculated cut-off values, which in turn limited the day-to-day utility of CAP measurements in clinical practice. This paper reviews published studies trying to suggest cut-off values usable in clinical practice.

Prevalence of non-alcoholic fatty liver disease among patients with non-diabetic chronic kidney disease detected by transient elastography

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) shares a close relationship with cardiovascular morbidity and mortality. The purpose of this study is to evaluate the frequency of NAFLD in the patients with non-diabetic chronic kidney disease (CKD).

METHODS

This cross-sectional study included 80 patients with non-diabetic CKD, of which, 50 patients were on hemodialysis (HD) and 30 patients had CKD stage G3-5 not on dialysis. These patients were randomly selected from Ain Shams University Hospitals, Cairo, Egypt. Patients with diabetes mellitus, obesity, alcohol intake, viral hepatitis, or drug-induced liver steatosis were excluded from this study. Importantly, the controlled attenuation parameter (CAP) (dB/m) of liver steatosis (S0-S3) and liver stiffness/fibrosis measurement (F0-F4) were measured using transient elastography (Fibroscan^®). Other evaluations included complete blood count, routine blood chemistry, and C-reactive protein (CRP) titer.

RESULTS

In total, 45 (56.25%) (30 males, 15 females) out of total 80 studied patients were reported to have NAFLD. There were 29 patients with end-stage renal disease who were on regular HD and 16 patients with pre-dialysis CKD G3-5. The mean CAP values of hepatic steatosis in the patients with CKD on dialysis and patients with pre-dialysis CKD were 265.41 ± 52.73 and 259 ± 44.8 dB/m, respectively. A significant association between the severity of hepatic steatosis degree with decreased glomerular filtration rate and increased CKD stage was observed in this study. The degree of liver stiffness was significantly related to an increased hepatic steatosis grade. A significant positive correlation was found between the degree of NAFLD and serum levels of alanine aminotransferase, aspartate transaminase, total cholesterol, triglycerides, low-density lipoprotein, and CRP titer (P < 0.05). Importantly, NAFLD was significantly associated with an evident history of cardiovascular disease (CVD) among the studied patients.

CONCLUSION

A high frequency of NAFLD (56%) was observed among the patients with non-diabetic CKD on hemodialysis and patients with pre-dialysis CKD. NAFLD may be associated with an increased liver stiffness grade and CVD among those patients.

Accuracy of controlled attenuation parameter compared with ultrasound for detecting hepatic steatosis in children with severe obesity

OBJECTIVES

To determine the diagnostic accuracy of controlled attenuation parameter (CAP) on FibroScan® in detecting and grading steatosis in a screening setting and perform a head-to-head comparison with conventional B-mode ultrasound.

METHODS

Sixty children with severe obesity (median BMI z-score 3.37; median age 13.7 years) were evaluated. All underwent CAP and US using a standardized scoring system. Magnetic resonance spectroscopy proton density fat fraction (MRS-PDFF) was used as a reference standard.

RESULTS

Steatosis was present in 36/60 (60%) children. The areas under the ROC (AUROC) of CAP for the detection of grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.80 (95% CI: 0.67-0.89), 0.77 (95% CI: 0.65-0.87), and 0.79 (95% CI: 0.66-0.88), respectively. The AUROC of US for the detection of grade ≥ S1 steatosis was 0.68 (95% CI: 0.55-0.80) and not significantly different from that of CAP (p = 0.09). For detecting ≥ S1 steatosis, using the optimal cutoffs, CAP (277 dB/m) and US (US steatosis score ≥ 2) had a sensitivity of 75% and 61% and a specificity of 75% and 71%, respectively. When using echogenicity of liver parenchyma as only the scoring item, US had a sensitivity of 70% and specificity of 46% to detect ≥ S1 steatosis. The difference in specificity of CAP and US when using only echogenicity of liver parenchyma of 29% was significant (p = 0.04).

CONCLUSION

The overall performance of CAP is not significantly better than that of US in detecting steatosis in children with obesity, provided that the standardized scoring of US features is applied. When US is based on liver echogenicity only, CAP outperforms US in screening for any steatosis (≥ S1).

KEY POINTS

• The areas under the ROC curves of CAP and ultrasound (US) for detecting grade ≥ S1 steatosis were 0.80 and 0.68, respectively, and were not significantly different (p = 0.09). • For detecting grade ≥ S1 steatosis in severely obese children, CAP had a sensitivity of 75% and a specificity of 75% at its optimal cutoff value of 277 dB/m. • For detecting grade ≥ S1 steatosis in clinical practice, both CAP and US can be used, provided that the standardized scoring of US images is used.

Diagnostic Performance of Vibration-Controlled Transient Elastography in Liver Transplant Recipients

BACKGROUND & AIMS

Vibration-controlled transient elastography (VCTE) is a non-invasive tool for detecting hepatic steatosis and fibrosis in patients who have not received liver transplants. We aimed to evaluate the diagnostic performance of VCTE in detection of hepatic steatosis and fibrosis in patients who have undergone liver transplantation.

METHODS

We performed a prospective study of 99 liver transplant recipients assessed by VCTE using a standard protocol. Controlled attenuation parameter cutoff values for pairwise steatosis grade and liver stiffness measurements (LSM) and cutoff values for pairwise fibrosis stage were determined using cross-validated area under the receiver operating characteristics (AUROC) curve analyses. We calculated sensitivity (fixed at 90%) and specificity (fixed at 90%) values.

RESULTS

A controlled attenuation parameter cutoff value of 270 dB/m detected any hepatic steatosis with an AUROC of 0.88 (95% CI, 0.78-0.93). VCTE detected steatosis grades 2-3 vs 0-1 with an AUROC of 0.94 (95% CI, 0.89-0.99) and steatosis grade 3 vs 0-2 was similar and AUROC of 0.89 (95% CI, 0.83-0.96). When we used an LSM cutoff value of 10.5 kPa, VCTE identified patients with advanced fibrosis (fibrosis stages ≥ 3) with an AUROC of 0.94 (95% CI, 0.88-0.99). At fixed sensitivity, the cutoff LSM value of 10.5k Pa excluded advanced fibrosis with a negative predictive value of 0.99. At fixed specificity, the cutoff LSM value of 16.9 kPa detected advanced fibrosis with a sensitivity of 0.86, a positive predictive value (PPV) of 0.40, and a negative predictive value of 0.99.

CONCLUSIONS

VCTE accurately detects hepatic steatosis and fibrosis in recipients of liver transplants. This non-invasive method might be used to identify patients in need of confirmatory liver biopsy analysis.

Diagnostic performance of fibroscan and computed tomography in 322 normal alanine aminotransferase non-obese non-alcoholic fatty liver disease patients diagnosed by ultrasound

AIMS OF THE STUDY

To compare the evaluation of various non-invasive examination include ultrasound, fibroscan and computed tomography (CT) in normal alanine aminotransferase (ALT) non-obese patients, to analyse the consistency and advantages among these non-invasive examination in non-alcoholic fatty liver disease (NAFLD) patients.

METHODS USED TO CONDUCT THE STUDY

About 322 cases of non-obese NAFLD patients (BMI < 25 kg/m² ) with normal ALT were enroled. All patients were diagnosed with fatty liver by abdominal ultrasonography. Meanwhile, computed tomography and fibroscan were used to evaluate the existence and severity of fatty liver.

RESULTS OF THE STUDY

A 47.52% and 67.70% patients who diagnosed as NAFLD by ultrasound were unable to be diagnosed with fatty liver in accordance with the standard of controlled attenuation parameter (CAP) value by fibroscan and liver/spleen density ratio (L/S ratio) by CT. The evaluation of NAFLD by CAP standard were influenced by several factors, while only age and Triglyceride (TG) may affect the judgement of fatty liver when CT was used. Liver stiffness measurement (LSM) affects the diagnostic coincidence rate of fibroscan, CT and ultrasound. Statistical difference could be found among different LSM groups in the severity of NAFLD evaluated by Fibroscan and CT.

CONCLUSIONS DRAWN FROM THE STUDY AND CLINICAL IMPLICATIONS

There is a discrepancy in the evaluation NAFLD by fibroscan, CT and ultrasound. LSM may affect the diagnostic coincidence rate of fibroscan, CT and ultrasound. Non-invasive assessment model including multiple clinical data and image results should be investigated in evaluating the degree of NAFLD. Interpretation of the diagnostic results about fibroscan, CT and ultrasound in the evaluation of NAFLD should take into account the specific clinical data of each patient.

Diagnostic Accuracy of FibroScan and Factors Affecting Measurements

Evaluating liver steatosis and fibrosis is important for patients with non-alcoholic fatty liver disease. Although liver biopsy and pathological assessment is the gold standard for these conditions, this technique has several disadvantages. The evaluation of steatosis and fibrosis using ultrasound B-mode imaging is qualitative and subjective. The liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) determined using FibroScan are the evidence-based non-invasive measures of liver fibrosis and steatosis, respectively. The LSM and CAP measurements are carried out simultaneously, and the median values of more than ten valid measurements are used to quantify liver fibrosis and steatosis. Here, we demonstrate that the reliability of the LSM depends on the interquartile range to median ratio (IQR/Med), but CAP values do not depend on IQR/Med. In addition, the LSM is affected by inflammation, congestion, and cholestasis in addition to fibrosis, while CAP values are affected by the body mass index in addition to steatosis. We also show that the M probe provides higher LSM values but lower CAP values than the XL probe in the same population. However, there was no statistically significant difference between the diagnostic accuracies of the two probes. These findings are important to understand the reliability of FibroScan measurements and the factors influencing measurement values for all patients.

Clinical assessment and management of liver fibrosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is among the most frequent etiologies of cirrhosis worldwide, and it is associated with features of metabolic syndrome; the key factor influencing its prognosis is the progression of liver fibrosis. This review aimed to propose a practical and stepwise approach to the evaluation and management of liver fibrosis in patients with NAFLD, analyzing the currently available literature. In the assessment of NAFLD patients, it is important to identify clinical, genetic, and environmental determinants of fibrosis development and its progression. To properly detect fibrosis, it is important to take into account the available methods and their supporting scientific evidence to guide the approach and the sequential selection of the best available biochemical scores, followed by a complementary imaging study (transient elastography, magnetic resonance elastography or acoustic radiation force impulse) and finally a liver biopsy, when needed. To help with the selection of the most appropriate method a Fagan′s nomogram analysis is provided in this review, describing the diagnostic yield of each method and their post-test probability of detecting liver fibrosis. Finally, treatment should always include diet and exercise, as well as controlling the components of the metabolic syndrome, +/- vitamin E, considering the presence of sleep apnea, and when available, allocate those patients with advanced fibrosis or high risk of progression into clinical trials. The final end of this approach should be to establish an opportune diagnosis and treatment of liver fibrosis in patients with NAFLD, aiming to decrease/stop its progression and improve their prognosis.

Effects of obesity reduction on transient elastography-based parameters in pediatric non-alcoholic fatty liver disease

AIM

To clarify the effects of obesity reduction on non-alcoholic fatty liver disease (NAFLD) in obese children.

METHODS

Twenty-six obese pediatric NAFLD patients (median age, 13.0 years; range, 6.4-16.6 years), who underwent obesity management supported by regular hospital visits and/or hospital admission, were studied to explore how reductions in weight and body mass index (BMI) percentile affected two transient elastography-based parameters: controlled attenuation parameter (CAP) and liver stiffness (LS), which reflect the degree of hepatic fat deposition and liver fibrosis, respectively.

RESULTS

Univariate analysis revealed that CAP reduction was correlated positively with baseline CAP and reductions in weight and BMI percentile (r = 0.320-0.525), whereas LS reduction was correlated positively with baseline LS and reductions in weight, BMI percentile, aspartate transaminase, and alanine aminotransferase (r = 0.385-0.625). Multivariate analysis revealed that baseline CAP and reduction in weight were significantly associated with CAP reduction, whereas reduction in weight and alanine aminotransferase were significantly associated with LS reduction. Short-term weight control by hospital admission (24.9 ± 9.5 days) provided significantly higher reductions in weight and BMI percentile (both P < 0.001) and was associated with reductions of CAP and LS (P = 0.04 and 0.01) compared with regular hospital visit-supported self-directed weight management (0.9 ± 0.8 years).

CONCLUSIONS

Weight reduction in obese pediatric NAFLD patients resulted in reduced hepatic fat deposition and liver stiffness. Weight control by short-term hospital admission is an alternative approach to regular hospital visit-supported self-directed weight management in NAFLD patients who fail to reduce obesity.

Usefulness of Different Imaging Modalities in Evaluation of Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are becoming some of the major health problems in well-developed countries, together with the increasing prevalence of obesity, metabolic syndrome, and all of their systemic complications. As the future prognoses are even more disturbing and point toward further increase in population affected with NAFLD/NASH, there is an urgent need for widely available and reliable diagnostic methods. Consensus on a non-invasive, accurate diagnostic modality for the use in ongoing clinical trials is also required, particularly considering a current lack of any registered drug for the treatment of NAFLD/NASH. The aim of this narrative review was to present current information on methods used to assess liver steatosis and fibrosis. There are several imaging modalities for the assessment of hepatic steatosis ranging from simple density analysis by computed tomography or conventional B-mode ultrasound to magnetic resonance spectroscopy (MRS), magnetic resonance imaging proton density fat fraction (MRI-PDFF) or controlled attenuation parameter (CAP). Fibrosis stage can be assessed by magnetic resonance elastography (MRE) or different ultrasound-based techniques: transient elastography (TE), shear-wave elastography (SWE) and acoustic radiation force impulse (ARFI). Although all of these methods have been validated against liver biopsy as the reference standard and provided good accuracy, the MRS and MRI-PDFF currently outperform other methods in terms of diagnosis of steatosis, and MRE in terms of evaluation of fibrosis.

Serum visfatin level as a noninvasive marker for nonalcoholic fatty liver disease in children and adolescents with obesity: relation to transient elastography with controlled attenuation parameter

BACKGROUND

Obesity is associated with an increased risk of nonalcoholic fatty liver disease (NAFLD). Visfatin is an adipokine produced by visceral fat tissue and liver cells. Transient elastography with controlled attenuation parameter (CAP) noninvasively assesses liver fibrosis and steatosis.

AIM

To measure visfatin level in 80 children and adolescents with obesity as a potential biomarker for NAFLD and assess its relation to transient elastography.

METHODS

Abdominal ultrasound, liver stiffness and CAP measurements were performed for all patients. Fasting lipid profile, fasting blood glucose, insulin level, liver and kidney functions, coagulation profile and serum visfatin levels were assessed.

RESULTS

Among patients with obesity, 31 (38.8%) had NAFLD and 16 (20%) patients had elevated alanine aminotransferase (ALT), while 9 (11.2%) had both NAFLD and elevated ALT. Transient elastography showed that 12.5% had fibrosis stage F1, 2.5% had F2 and another 2.5% had F3 while none had F4. Using CAP, 23.8, 13.8 and 17.5% had S1, S2 and S3, respectively. Serum visfatin levels were significantly elevated in all patients compared with nonobese controls. Higher visfatin levels were found among patients with dyslipidemia, NAFLD, elevated ALT and steatosis defined by CAP. Serum visfatin was related to the degree of fibrosis and steatosis. Visfatin cutoff value 18 ng/mL could significantly detect the presence of NAFLD with 83.9% sensitivity and 81.4% specificity. Serum visfatin was positively correlated to BMI, waist circumference, waist/hip ratio, ALT, total cholesterol, liver stiffness and CAP.

CONCLUSIONS

Visfatin could be a promising serum biomarker for monitoring liver disease among pediatric patients with obesity.

Hepatic steatosis and liver fat contents in liver transplant recipients are associated with serum adipokines and insulin resistance

Our data about pathogenesis of hepatic steatosis after liver transplantation is scarce. This study aimed to investigate the association between serum adipokines and insulin resistance with hepatic steatosis in liver transplant recipients. We investigated the association between insulin resistance, serum adiponectin, insulin, and leptin with hepatic steatosis in a cohort of liver transplant recipients. Homeostatic model assessment of insulin resistance 2 (HOMA 2-IR) was used for estimation of insulin resistance. Hepatic steatosis was determined using ultrasound and controlled attenuation parameter (CAP). A total of 178 patients were included. 79 patients (44.4%) had hepatic steatosis. Serum adiponectin (OR: 0.912; 95% CI 0.869–0.957; P < 0.001), serum leptin (OR: 1.060; 95% CI 1.017–1.102; P = 0.005), HOMA2-IR (OR: 1.671; 95% CI 1.049–2.662; P = 0.031), and post-transplant diabetes mellitus (PTDM) (OR: 5.988; 95% CI 1.680–21.276; P = 0.006) were independently associated with hepatic steatosis after liver transplantation. CAP values were negatively correlated with serum adiponectin (P = 0.011) and positively correlated with serum insulin (P = 0.001), leptin (P < 0.001) and HOMA2-IR (P < 0.001). Insulin resistance and alterations in adipokines might have central role in pathogenesis of hepatic steatosis after liver transplantation and can be targeted for diagnostic and therapeutic purposes.

Usefulness of Controlled Attenuation Parameter in Detecting and Monitoring Hepatic Steatosis with MRI-PDFF as Reference

BACKGROUND

Controlled attenuation parameter (CAP) has been developed to estimate the extent of hepatic steatosis.

AIMS

The purpose was to evaluate the usefulness of CAP in assessing hepatic steatosis and its change using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as reference standard.

METHODS

Consecutive patients with liver steatosis were enrolled prospectively. We assessed hepatic steatosis with CAP and MRI-PDFF at enrollment and 12-month follow-up. The correlations between the two methods were analyzed. With MRI-PDFF as reference, the performance of CAP in diagnosis of steatosis severity and its changes was assessed.

RESULTS

A total of 50 patients were enrolled, and 45 of them had follow-up MRI-PDFF and CAP at a median interval of 399 days. The mean hepatic steatosis was 13.4% by MRI-PDFF and 291.6 dB/m by CAP. There were positive correlations between CAP and MRI-PDFF in steatosis severity and its change. The median value of CAP was 254, 301.5, and 329.5 dB/m for steatosis < 10%, 10-20%, and > 20%, respectively. For CAP in detecting steatosis ≥ 10% and > 20%, the diagnostic performance was 0.821 and 0.814. With the cutoff of 275 dB/m for ≥ 10% steatosis, the positive predictive value was 84.8%. With the cutoff of 325 dB/m for > 20% steatosis, the negative predictive value was 91.9%. In multiple linear regression, one dB/m change by CAP was associated with 0.039% change by MRI-PDFF.

CONCLUSIONS

In assessing liver fat content, CAP correlated with MRI-PDFF and was useful for detection and monitoring of hepatic steatosis.

Quantitative ultrasound approaches for diagnosis and monitoring hepatic steatosis in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is a major global health concern with increasing prevalence, associated with obesity and metabolic syndrome. Recently, quantitative ultrasound-based imaging techniques have dramatically improved the ability of ultrasound to detect and quantify hepatic steatosis. These newer ultrasound techniques possess many inherent advantages similar to conventional ultrasound such as universal availability, real-time capability, and relatively low cost along with quantitative rather than a qualitative assessment of liver fat. In addition, quantitative ultrasound-based imaging techniques are less operator dependent than traditional ultrasound. Here we review several different emerging quantitative ultrasound-based approaches used for detection and quantification of hepatic steatosis in patients at risk for nonalcoholic fatty liver disease. We also briefly summarize other clinically available imaging modalities for evaluating hepatic steatosis such as MRI, CT, and serum analysis.

NAFLD as a continuum: from obesity to metabolic syndrome and diabetes

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) has been increasing rapidly. It is nowadays recognized as the most frequent liver disease, affecting a quarter of global population and regularly coexisting with metabolic disorders such as type 2 diabetes, hypertension, obesity, and cardiovascular disease. In a more simplistic view, NAFLD could be defined as an increase in liver fat content, in the absence of secondary cause of steatosis. In fact, the clinical onset of the disease is a much more complex process, closely related to insulin resistance, limited expandability and dysfunctionality of adipose tissue. A fatty liver is a main driver for a new recognized liver-pancreatic α-cell axis and increased glucagon, contributing to diabetes pathophysiology.

MAIN TEXT

This review will focus on the clinical and pathophysiological connections between NAFLD, insulin resistance and type 2 diabetes. We reviewed non-invasive methods and several scoring systems for estimative of steatosis and fibrosis, proposing a multistep process for NAFLD evaluation. We will also discuss treatment options with a more comprehensive view, focusing on the current available therapies for obesity and/or type 2 diabetes that impact each stage of NAFLD.

CONCLUSION

The proper understanding of NAFLD spectrum-as a continuum from obesity to metabolic syndrome and diabetes-may contribute to the early identification and for establishment of targeted treatment.

Randomized Clinical Trial: Bergamot Citrus and Wild Cardoon Reduce Liver Steatosis and Body Weight in Non-diabetic Individuals Aged Over 50 Years

Background: Non-alcoholic fatty liver disease is the most common cause of liver-related morbidity and mortality in the world. However, no effective pharmacological treatment for this condition has been found. Purpose: This study evaluated the effect of a nutraceutical containing bioactive components from Bergamot citrus and wild cardoon as a treatment for individuals with fatty liver disease. The primary outcome measure was the change in liver fat content. Methods: A total of 102 patients with liver steatosis were enrolled in a double-blind placebo controlled clinical trial. The intervention group received a nutraceutical containing a Bergamot polyphenol fraction and Cynara Cardunculus extract, 300 mg/day for 12 weeks. The control group received a placebo daily. Liver fat content, by transient elastography, serum transaminases, lipids and glucose were measured at the baseline and the end of the study. Results: We found a greater liver fat content reduction in the participants taking the nutraceutical rather than placebo (-48.2 ± 39 vs. -26.9 ± 43 dB/m, p = 0.02); The percentage CAP score reduction was statistically significant in those with android obesity, overweight/obesity as well as in women. However, after adjustment for weight change, the percentage CAP score reduction was statistically significant only in those over 50 years (44 vs. 78% in placebo and nutraceutical, respectively, p = 0.007). Conclusions: This specific nutraceutical containing bioactive components from Bergamot and wild cardoon reduced the liver fat content during 12 weeks in individuals with liver steatosis over 50 years. If confirmed, this nutraceutical could become the cornerstone treatment of patients affected by liver steatosis. Clinical Trial Registration: www.isrctn.com, identifier ISRCTN12833814.

Quantification of hepatic steatosis with ultrasound: promising role of attenuation imaging coefficient in a biopsy-proven cohort

OBJECTIVES

To prospectively assess the role of the US attenuation imaging coefficient (AC) for the diagnosis and quantification of hepatic steatosis.

METHODS

One hundred and one patients underwent liver biopsy and US-AC measurement on the same day. Liver steatosis was graded according to biopsy as absent (S0 < 5%), mild (S1 5-33%), moderate (S2 33-66%), or severe (S3 > 66%); liver fibrosis was graded from F0 to F4. The correlation between AC and steatosis on pathology (%) was calculated using the Pearson correlation coefficient. The Student t or Mann-Whitney U test was used to compare continuous variables and ROC curve analysis was used to assess diagnostic performance of AC in diagnosing steatosis.

RESULTS

Overall, 43 (42%), 35 (35%), 12 (12%), and 11 (11%) patients were classified as S0, S1, S2, and S3, respectively. The AC was positively correlated with steatosis as a continuous variable (%) on pathology (r = 0.58, p < 0.01). Patients with steatosis of any grade had a higher AC than those without steatosis (mean 0.77 ± 0.13 vs. 0.63 ± 0.09 dB/cm/MHz, respectively; p < 0.01, AUROC = 0.805). Patients with S2-S3 had a higher AC than patients with S0-1 (0.85 ± 0.11 vs. 0.67 ± 0.11 dB/cm/MHz, respectively; p < 0.01, AUROC = 0.892). AC > 0.69 dB/cm/MHz had a sensitivity and specificity of 76% and 86%, respectively, for diagnosing any grade of steatosis (S1-S3), and AC > 0.72 dB/cm/MHz had a sensitivity and specificity of 96% and 74%, respectively, for diagnosing S2-S3. The presence of advanced fibrosis (F3-F4) did not affect the calculated AC.

CONCLUSIONS

The attenuation imaging coefficient is a promising quantitative technique for the non-invasive diagnosis and quantification of hepatic steatosis.

KEY POINTS

• Measurement of the attenuation coefficient is achieved with a very high rate of technical success. • We found a significant positive correlation between the attenuation coefficient and the grade of steatosis on pathology. • The attenuation imaging coefficient is a promising quantitative technique for the noninvasive diagnosis and quantification of hepatic steatosis.

Performance of Controlled Attenuation Parameter in Patients with Advanced Chronic Liver Disease and Portal Hypertension

BACKGROUND

Liver stiffness (LS) measured by vibration-controlled transient elastography (VCTE) is influenced by liver fibrosis and hepatic perfusion pressure. VCTE-based controlled attenuation parameter (CAP) is a noninvasive marker for hepatic steatosis (HS).

AIMS

To investigate the diagnostic performance of CAP in patients with advanced chronic liver disease (ACLD)/portal hypertension (PHT: hepatic venous pressure gradient (HVPG) ≥ 6 mmHg).

METHODS

Eighty-eight patients with LS ≥ 10 kPa and/or HVPG ≥ 6 mmHg who underwent simultaneous liver biopsy, CAP, and HVPG measurement were included. HS was histologically graded according to the modified Brunt classification.

RESULTS

Patient characteristics: Mean MELD:11 (standard derivation [SD] ± 4), median HVPG:16 (interquartile range [IQR]10-19) mmHg, median LS:27.4 (IQR 16.2-48.9) kPa, and mean CAP:221 (SD ± 75) dB/m. According to histology, 47 (53.4%) patients had no HS (S0), 28 (31.8%) had S1, 11 (12.5%) had S2, and 2 (2.3%) had S3. The area under the receiver operating characteristic curve (AUROC) of CAP for diagnosing any HS (S0 vs. ≥ S1) was 0.692 (95% confidence interval [95% CI] 0.582-0.802) in the overall cohort, 0.830 (95% CI 0.637-1.0) in patients with HVPG < 10 mmHg, and 0.629 (95% CI 0.497-0.761) in patients with clinically significant portal hypertension (CSPH; HVPG ≥ 10 mmHg; n = 69). Using the established cutoff for any HS (248 dB/m), the sensitivity/specificity of CAP was only 48.8%/76.6%, respectively. In contrast, the AUROC and sensitivity/specificity (cutoff 268 dB/m) for diagnosing HS ≥ S2 were 0.842 (95% CI 0.747-0.936) and 84.6%/81.3%, respectively. CAP correlated with the percentage of steatotic hepatocytes (Spearman's ρ = 0.402; p ≤ 0.001) and showed a weak correlation with liver stiffness (ρ = 0.225; p = 0.035).

CONCLUSIONS

The diagnostic performance of CAP for any HS seems to be limited in patients with ACLD, if CSPH is present.

Application of transient elastography in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Although it has become one of the leading causes of cirrhosis and hepatocellular carcinoma in the Western world, the proportion of NAFLD patients developing these complications is rather small. Therefore, current guidelines recommend non-invasive tests for the initial assessment of NAFLD. Among the available non-invasive tests, transient elastography by FibroScan^® (Echosens, Paris, France) is commonly used by hepatologists in Europe and Asia, and the machine has been introduced to the United States in 2013 with rapid adoption. Transient elastography measures liver stiffness and the controlled attenuation parameter simultaneously and can serve as a one-stop examination for both liver steatosis and fibrosis. Liver stiffness measurement also correlates with clinical outcomes and can be used to select patients for varices screening. Although obesity is a common reason for measurement failures, the development of the XL probe allows successful measurements in the majority of obese patients. This article reviews the performance and limitations of transient elastography in NAFLD and highlights its clinical applications. We also discuss the reliability criteria for transient elastography examination and factors associated with false-positive liver stiffness measurements.

The impact of hepatic steatosis on portal hypertension

Background and aims

Studies in animal models have suggested that hepatic steatosis impacts on portal pressure, potentially by inducing liver sinusoidal endothelial dysfunction and thereby increasing intrahepatic resistance. Thus, we aimed to evaluate the impact of hepatic steatosis on hepatic venous pressure gradient (HVPG) in patients with chronic liver disease.

Method

261 patients undergoing simultaneous HVPG measurements and controlled attenuation parameter (CAP)-based steatosis assessment were included in this retrospective study.

Results

The majority of patients had cirrhosis (n = 205; 78.5%) and n = 191 (73.2%) had clinically significant portal hypertension (CSPH; HVPG≥10mmHg). Hepatic steatosis (S1/2/3; CAP ≥248dB/m) was present in n = 102 (39.1%). Overall, HVPG was comparable between patients with vs. without hepatic steatosis (15.5±7.5 vs. 14.8±7.7mmHg; p = 0.465). Neither in patients with HVPG (<6mmHg; p = 0.371) nor in patients with mild portal hypertension (HVPG 6–9mmHg; p = 0.716) or CSPH (HVPG≥10mmHg; p = 0.311) any correlation between CAP and HVPG was found. Interestingly, in patients with liver fibrosis F2/3, there was a negative correlation between CAP and HVPG (Pearson’s ρ:-0.522; p≤0.001). In multivariate analysis, higher CAP was an independent ‘protective’ factor for the presence of CSPH (odds ratio [OR] per 10dB/m: 0.92, 95% confidence interval [CI]:0.85–1.00; p = 0.045), while liver stiffness was associated with the presence of CSPH (OR per kPa: 1.26, 95%CI: 1.17–1.36; p≤0.001). In 78 patients, in whom liver biopsy was performed, HVPG was neither correlated with percentage of histological steatosis (p = 0.714) nor with histological steatosis grade (p = 0.957).

Conclusion

Hepatic steatosis, as assessed by CAP and liver histology, did not impact on HVPG in our cohort comprising a high proportion of patients with advanced chronic liver disease. However, high CAP values (i.e. pronounced hepatic steatosis) might lead to overestimation of liver fibrosis by ‘artificially’ increasing transient elastography-based liver stiffness measurements.