Current status of imaging in nonalcoholic fatty liver disease

Non-invasive multispectral optoacoustic tomography resolves intrahepatic lipids in patients with hepatic steatosis

Hepatic steatosis is characterized by intrahepatic lipid accumulation and may lead to irreversible liver damage if untreated. Here, we investigate whether multispectral optoacoustic tomography (MSOT) can offer label-free detection of liver lipid content to enable non-invasive characterization of hepatic steatosis by analyzing the spectral region around 930 nm, where lipids characteristically absorb. In a pilot study, we apply MSOT to measure liver and surrounding tissues in five patients with liver steatosis and five healthy volunteers, revealing significantly higher absorptions at 930 nm in the patients, while no significant difference was observed in the subcutaneous adipose tissue of the two groups. We further corroborated the human observations with corresponding MSOT measurements in high fat diet (HFD) - and regular chow diet (CD)-fed mice. This study introduces MSOT as a potential non-invasive and portable technique for detecting/monitoring hepatic steatosis in clinical settings, providing justification for larger studies.

Hepatic fat as a novel marker for high-risk coronary atherosclerotic plaque features in familial hypercholesterolaemia

BACKGROUND & AIMS

Hepatic steatosis has been associated with increased risk of coronary artery disease. Individuals with familial hypercholesterolaemia have accelerated but variable progression of coronary artery disease. We investigated whether hepatic steatosis is associated with novel coronary atherosclerosis biomarkers in adults with heterozygous familial hypercholesterolaemia, using comprehensive coronary computed tomographic angiography.

METHODS

We conducted a cross-sectional study of 213 asymptomatic patients with familial hypercholesterolaemia (median age 54.0 years, 59 % female) who underwent coronary computed tomographic angiography for cardiovascular risk assessment in an outpatient clinic. High-risk plaque features, plaque volume and pericoronary adipose tissue attenuation were assessed. From concurrently captured upper abdominal images, severity of hepatic steatosis was computed, as liver minus spleen computed tomography attenuation and stratified into quartiles.

RESULTS

Of 213 familial hypercholesterolaemia patients, 59 % had coronary artery calcium, 36 % obstructive coronary artery disease (≥50 % stenosis) and 77 % high-risk plaque features. Increasing hepatic steatosis was associated with higher calcium scores, more high-risk plaque features and presence of obstructive coronary artery disease. Hepatic steatosis was associated with the presence of high-risk plaque features (OR: 1.48; 95 % CI: 1.09-2.00; p = 0.01), particularly in the proximal coronary segments (OR: 1.52; 95 % CI: 1.18-1.96; p = 0.001). Associations persisted on multivariable logistic regression analysis adjusting for cardiometabolic factors, obstructive coronary artery disease and calcium score. Hepatic steatosis was associated with higher plaque volumes (Q4: 499 mm³ vs Q1: 414 mm³, p = 0.02), involving mainly low attenuation and noncalcified plaques (both p = 0.03). No differences in pericoronary adipose tissue attenuation were observed.

CONCLUSIONS

Hepatic steatosis is associated with multiple indices of advanced coronary atherosclerosis in familial hypercholesterolaemia patients, particularly high-risk plaque features, independent of conventional cardiovascular risk factors and markers. This may involve specific mechanisms related to hepatic steatosis.

CLINICAL TRIAL NUMBER

N/A.

Reliability of Non-invasive Liver Fibrosis Assessment Tools Versus Biopsy in Pre- and Post-bariatric Surgery Patients with Non-alcoholic Fatty Liver Disease

PURPOSE

Liver biopsy (LBx) remains the gold standard to assess fibrosis in non-alcoholic fatty liver disease (NAFLD). Biochemical markers are also useful, but their reliability is not clear in patients with morbid obesity. We assessed the performance of six non-invasive fibrosis assessment tools before and after bariatric surgery (BSx) using LBx.

MATERIALS AND METHODS

This is a cross-sectional and prospective cohort study. LBx was performed at the time of BSx and 12-month post-operatively and assessed using the Brunt system. Clinical and biochemical measurements were collected at the same time points and six non-invasive fibrosis assessment tools were calculated.

RESULTS

One hundred seventy patients had BSx; 79.4% female; age was 46.6 ± 9.8 years, and BMI was 48.6 ± 7.5 kg/m². From liver histology, 88% had F0-F2 and 11.2% F3-F4. At BSx, aspartate aminotransferase to platelet ratio index (APRI) and FIB-4 had better accuracy (0.86 and 0.88) with specificity of 96.6% and 94.0% and negative predictive values (NPV) of 88.9% and 93.7%. However, sensitivity (6.7% and 40.0%) and positive predictive values (PPV) (20.0% and 46.2%) were low. Twelve months post-surgery (n = 54), 88.9% of patients had F0-F2 and 11.1% had F3-F4. Fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS) had the best accuracy (0.79 and 0.77) with specificity of 83.7% and 86.9% and NPV of 92.3% and 86.9%. However, sensitivity (25% and 0%) and PPV (12.5% and 0%) were low.

CONCLUSION

Overall, FIB-4, APRI, and NFS showed similar performances with higher accuracy, specificity, and NPV. Sensitivity and PPV were low. These tests are more useful at excluding advanced fibrosis.

Development and validation of a new nomogram to screen for MAFLD

BACKGROUND AND AIM

Metabolic dysfunction-associated fatty liver disease (MAFLD) poses significant health and economic burdens on all nations. Thus, identifying patients at risk early and managing them appropriately is essential. This study's goal was to develop a new predictive model for MAFLD. Additionally, to improve the new model's clinical utility, researchers limited the variables to readily available simple clinical and laboratory measures.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES) cycle 2017-2020.3, the study was a retrospective cross-sectional study involving 7300 participants. By least absolute shrinkage and selection operator (LASSO) regression, significant indicators independently associated with MAFLD were identified, and a predictive model called the MAFLD prediction nomogram (MPN) was developed. The study then compared the MPN with six existing predictive models for MAFLD. The model was evaluated by measuring the area under receiver operating characteristic curve (AUC), net reclassification index (NRI), integrated discrimination improvement (IDI), calibration curve, and decision curve analysis (DCA) curve.

RESULTS

In this study, researchers identified nine predictors from 33 variables, including age, race, arm circumference (AC), waist circumference (WC), body mass index (BMI), alanine aminotransferase (ALT)-to-aspartate aminotransferase (AST) ratio, triglyceride-glucose index (TyG), hypertension, and diabetes. The diagnostic accuracy of the MPN for MAFLD was significantly better than that of the other six existing models in both the training and validation cohorts (AUC 0.868, 95% confidence interval (CI) 0.858-0.877, and AUC 0.863, 95% CI 0.848-0.878, respectively). The MPN showed a higher net benefit than the other existing models.

CONCLUSIONS

This nonimaging-assisted nomogram based on demographics, laboratory factors, anthropometrics, and comorbidities better predicted MAFLD than the other six existing predictive models. Using this model, the general population with MAFLD can be assessed rapidly.

Neck Circumference for NAFLD Assessment during a 2-Year Nutritional Intervention: The FLiO Study

Neck circumference (NC) and its relationship to height (NHtR) and weight (NWtR) appear to be good candidates for the non-invasive management of non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the ability of routine variables to assess and manage NAFLD in 98 obese subjects with NAFLD included in a 2-year nutritional intervention program. Different measurements were performed at baseline, 6, 12 and 24 months. The nutritional intervention significantly improved the anthropometric, metabolic and imaging variables. NC was significantly associated with the steatosis degree at baseline (r = 0.29), 6 m (r = 0.22), 12 m (r = 0.25), and 24 m (r = 0.39) (all p < 0.05). NC was also significantly associated with visceral adipose tissue at all the study time-points (basal r = 0.78; 6 m r = 0.65; 12 m r = 0.71; 24 m r = 0.77; all p < 0.05). NC and neck ratios combined with ALT levels and HOMA-IR showed a good prediction ability for hepatic fat content and hepatic steatosis (at all time-points) in a ROC analysis. The model improved when weight loss was included in the panel (NC-ROC: 0.982 for steatosis degree). NC and ratios combined with ALT and HOMA-IR showed a good prediction ability for hepatic fat during the intervention. Thus, their application in clinical practice could improve the prevention and management of NAFLD.

Ultrasound and FibroScan® Controlled Attenuation Parameter in patients with MAFLD: head to head comparison in assessing liver steatosis

BACKGROUND

Controlled attenuation parameter (CAP) has been suggested as a new non-invasive measurement performed during transient elastography (TE) to assess liver steatosis. The aim of this study was to evaluate CAP values head to head with ultrasound (US) as reference standard.

METHODS

A consecutive cohort of patients attending abdominal US in an outpatient liver unit was included in this study with simultaneous CAP determination using the FibroScan^® M probe and fibrosis scored by TE. Patients were subdivided in four groups on the basis of risk factors for Metabolically Associated Fatty Liver Disease (MAFLD).

RESULTS

Four hundred thirty-five patients were included in the analysis: 221 (51%) were male; 117 (26.9%) were in control group, 144 (33.1%) in group 2 with inactive HCV or HBV infection and at low-risk for MAFLD, 134 (30.8%) in group 3 at high-risk of MAFLD, 40 (9.2%) in group 4 at high-risk of MAFLD and concomitant inactive HCV or HBV infection. Liver steatosis detected with US evaluation was observed in the 41% of the entire cohort; in particular in the 3.4%, 20.1%, 83.6% and 87.4% of the group 1, 2, 3 and 4, respectively (p < 0.001). In patients at high-risk factor for MAFLD (group 3 and 4), CAP median levels were found statistically different among the severity-grading groups for US steatosis (S0 [n.27], ≥S1 [n.59], ≥S2 + S3 [n.89]), observing higher CAP levels in patients with a higher steatosis grade (≥S2 + S3 327.5 [±40.6] vs ≥S1 277.7 [±45.6] vs S0 245.1 [±47.4]; p < 0.001 for the whole cohort analysis) (p < 0.001 between ≥S2 + S3 and ≥S1) (p < 0.001 between ≥S2 + S3 and S0) (p = 0.004 between ≥S1 and S0). ROC analysis showed that the global performance of the CAP median level ≥ 258 to predict liver steatosis (S0 vs S1-3), was excellent with an Area Under the Curve (AUC) value of 0.87 [CI 95% 0. 835-0.904] with an 84% of sensitivity and a 78% of specificity, and a positive predictive value (PPV) of 73% and negative predictive value (NPV) of 88%. A TE-kPa median value <8.0 was detected in the 100%, 84%, 83.6% and 60% of patients in group 1, 2, 3 and 4, respectively. A TE-kPa median value >13.0 was detected in the 0%, 4.2%, 5.2% and 17.5% of patients in group 1, 2, 3 and 4, respectively.

CONCLUSIONS

CAP values are strongly associated with the standard US criteria for different degree of steatosis. Integrating TE up to 5% of patients may be identified at risk for advanced fibrosis.

Pulse-Echo Quantitative US Biomarkers for Liver Steatosis: Toward Technical Standardization

Excessive liver fat (steatosis) is now the most common cause of chronic liver disease worldwide and is an independent risk factor for cirrhosis and associated complications. Accurate and clinically useful diagnosis, risk stratification, prognostication, and therapy monitoring require accurate and reliable biomarker measurement at acceptable cost. This article describes a joint effort by the American Institute of Ultrasound in Medicine (AIUM) and the RSNA Quantitative Imaging Biomarkers Alliance (QIBA) to develop standards for clinical and technical validation of quantitative biomarkers for liver steatosis. The AIUM Liver Fat Quantification Task Force provides clinical guidance, while the RSNA QIBA Pulse-Echo Quantitative Ultrasound Biomarker Committee develops methods to measure biomarkers and reduce biomarker variability. In this article, the authors present the clinical need for quantitative imaging biomarkers of liver steatosis, review the current state of various imaging modalities, and describe the technical state of the art for three key liver steatosis pulse-echo quantitative US biomarkers: attenuation coefficient, backscatter coefficient, and speed of sound. Lastly, a perspective on current challenges and recommendations for clinical translation for each biomarker is offered.

The Focus on Core Genetic Factors That Regulate Hepatic Injury in Cattle Seems to be Important for the Dairy Sector’s Long-Term Development

The cattle during the perinatal period, as well as malnutrition, generate oxidative stress which leads to high culling rates of calves after calving across the world. Although metabolic diseases have such a negative impact on the welfare and economic value of dairy cattle, that becomes a serious industrial concern across the world. According to research, genetic factors have a role or controlling fat deposition in the liver by influencing the biological processes of hepatic lipid metabolism, insulin resistance, gluconeogenesis, oxidative stress, endoplasmic reticulum stress, and inflammation, all of which contribute to hepatic damage. This review focuses on the critical regulatory mechanisms of VEGF, mTOR/AKT/p53, TNF-alpha, Nf-kb, interleukin, and antioxidants that regulate lipid peroxidation in the liver via direct or indirect pathways, suggesting that they could be a potential critical therapeutic target for hepatic disease.

Bichromatic Imaging with Hemicyanine Fluorophores Enables Simultaneous Visualization of Non-alcoholic Fatty Liver Disease and Metastatic Intestinal Cancer

Simultaneous detection of different diseases via a single fluorophore is challenging. We herein report a bichromatic fluorophore named Cy-914 for the simultaneous diagnosis of non-alcoholic fatty liver disease (NAFLD) and metastatic intestinal cancer by leveraging its NIR-I/NIR-II dual-color imaging capability. Cy-914 with a pK_a of 6.98 exhibits high sensitivity to pH and viscosity, showing turn-on NIR-I fluorescence at 795 nm in an acidic tumor microenvironment, meanwhile displaying intense NIR-II fluorescence at 914/1030 nm under neutral to slightly basic viscous conditions. Notably, Cy-914 could sensitively and noninvasively monitor viscosity variations in the progression of NAFLD. More importantly, it was able to simultaneously visualize NAFLD (ex/em = 808/1000-1700 nm) and intestinal metastases (ex/em = 570/810-875 nm) in two independent channels without spectral cross interference after topical spraying, further improving fluorescence-guided surgery of tiny metastases less than 3 mm. This strategy may provide an understanding for developing multi-color fluorophores for multi-disease diagnosis.

How to select the quantitative magnetic resonance technique for subjects with fatty liver: A systematic review

BACKGROUND

Early quantitative assessment of liver fat content is essential for patients with fatty liver disease. Mounting evidence has shown that magnetic resonance (MR) technique has high accuracy in the quantitative analysis of fatty liver, and is suitable for monitoring the therapeutic effect on fatty liver. However, many packaging methods and postprocessing functions have puzzled radiologists in clinical applications. Therefore, selecting a quantitative MR imaging technique for patients with fatty liver disease remains challenging.

AIM

To provide information for the proper selection of commonly used quantitative MR techniques to quantify fatty liver.

METHODS

We completed a systematic literature review of quantitative MR techniques for detecting fatty liver, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Studies were retrieved from PubMed, Embase, and Cochrane Library databases, and their quality was assessed using the Quality Assessment of Diagnostic Studies criteria. The Reference Citation Analysis database (https:// www.referencecitationanalysis.com) was used to analyze citation of articles which were included in this review.

RESULTS

Forty studies were included for spectroscopy, two-point Dixon imaging, and multiple-point Dixon imaging comparing liver biopsy to other imaging methods. The advantages and disadvantages of each of the three techniques and their clinical diagnostic performances were analyzed.

CONCLUSION

The proton density fat fraction derived from multiple-point Dixon imaging is a noninvasive method for accurate quantitative measurement of hepatic fat content in the diagnosis and monitoring of fatty liver progression.

Quantitative dual-energy CT techniques in the abdomen

Advances in dual-energy CT (DECT) technology and spectral techniques are catalyzing the widespread implementation of this technology across multiple radiology subspecialties. The inclusion of energy- and material-specific datasets has ushered overall improvements in CT image contrast and noise as well as artifacts reduction, leading to considerable progress in radiologists' ability to detect and characterize pathologies in the abdomen. The scope of this article is to provide an overview of various quantitative clinical DECT applications in the abdomen and pelvis. Several of the reviewed applications have not reached mainstream clinical use and are considered investigational. Nonetheless awareness of such applications is critical to having a fully comprehensive knowledge base to DECT and fostering future clinical implementation.

Nonalcoholic Fatty Liver Disease: Review of Management for Primary Care Providers

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in the United States and worldwide. The progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), is a leading indication for liver transplant. Comorbidities associated with NAFLD development and NASH include type 2 diabetes, obesity, metabolic syndrome, and dyslipidemia. Extrahepatic morbidity and mortality are considerable as NAFLD is associated with an increased risk of cardiovascular disease and chronic kidney disease. Once NAFLD is diagnosed, the presence of liver fibrosis is the central determinant of hepatic prognosis. Severe liver fibrosis requires aggressive clinical management. No pharmacologic agents have regulatory approval in the United States for the treatment of NAFLD or NASH. Management is centered on efforts to reduce underlying obesity (lifestyle, medications, surgical or endoscopic interventions) and metabolic derangements (prediabetes, type 2 diabetes, hypertension, hyperlipidemia, and others). Current pharmacologic therapy for NAFLD is limited mainly to the use of vitamin E and pioglitazone, although other agents are being investigated in clinical trials. Cardiovascular and metabolic risk factors must also be assessed and managed. Here, NAFLD evaluation, diagnosis, and management are considered in the primary care setting and endocrinology clinics.

Comprehensive evaluation of microRNA as a biomarker for the diagnosis of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Current guidelines for HCC management recommend surveillance of high-risk patients every 6 mo using ultrasonography. Serum biomarkers, like alpha-fetoprotein (AFP), protein induced by vitamin K absence/antagonist-II (PIVKA-II) and lectin-reactive AFP, show suboptimal performance for detection of HCC, which is crucial for successful resection or treatment. Thus, there is a significant need for new biomarkers to aid early diagnosis of HCC. Studies have shown that the expression level of human microRNAs (miRNAs), a small, non-coding RNA species released into the blood, can serve as an early marker for various diseases, including HCC.

AIM

To evaluate the diagnostic role of miRNAs in HCC as single markers, signatures or in combination with known protein biomarkers.

METHODS

Our prospective, multicenter, case-control study recruited 660 participants (354 controls with chronic liver disease and 306 participants with HCC) and employed a strategy of initial screening by two independent methods, real-time quantitative PCR (n = 60) and next-generation sequencing (n = 100), to assess a large number of miRNAs. The results from the next-generation sequencing and real-time quantitative PCR screening approaches were then combined to select 26 miRNAs (including two putative novel miRNAs). Those miRNAs were analyzed for their diagnostic potential as single markers or in combination with other miRNAs or established protein biomarkers AFP and PIVKA-II via real-time quantitative PCR in training (n = 200) and validation cohorts (n = 300).

RESULTS

We identified 26 miRNAs that differentiated chronic liver disease controls from (early) HCC via two independent discovery approaches. Three miRNAs, miR-21-5p (miR-21), miR-320a and miR-186-5p, were selected by both methods. In the training cohort, only miR-21, miR-320d and miR-423 could significantly distinguish (Q < 0.05) between the HCC and chronic liver disease control groups. In the multivariate setting, miR-21 with PIVKA-II was selected as the best combination, resulting in an area under the curve of 0.87 for diagnosis and area under the curve of 0.74 for early diagnosis of HCC. In the validation cohort, only miR-21 and miR-423 could be confirmed as potential HCC biomarkers. A combination of miRNAs did not perform better than any single miRNA. Improvement of PIVKA-II performance through combination with miRNAs could not be confirmed in the validation panel. Two putative miRs, put-miR-6 and put-miR-99, were tested in the training and validation panels, but their expression could only be detected in very few samples and at a low level (cycle threshold between 31.24 and 34.97).

CONCLUSION

miRNAs alone or as a signature in combination with protein biomarkers AFP and PIVKA-II do not improve the diagnostic performance of the protein biomarkers.

Comparison of the Diagnostic Performance of Steatosis Indices for Discrimination of CT-Diagnosed Metabolic Dysfunction-Associated Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) was redefined as metabolic dysfunction-associated fatty liver disease (MAFLD) in 2020. Due to this, further validation of the non-invasive tests used in NAFLD diagnosis is required for MAFLD. There are five known steatosis indices for computed tomography (CT)-diagnosed MAFLD. These indices include the fatty liver index (FLI), the hepatic steatosis index (HSI), the lipid accumulation product (LAP), the visceral adiposity index (VAI), and the Zhejiang University index (ZJU). We aimed to analyze the diagnostic abilities of these five widely known steatosis indices for CT-diagnosed MAFLD. From March 2012 to October 2019, we retrospectively analyzed the clinical information and images of 1300 adults aged ≥19 years who underwent CT scans at our institution. To compare differences, the Chi-square test and independent t-test were used for categorical and continuous variables, respectively. The area under the receiver operating characteristic (AUROC) curve was used to validate the diagnostic accuracy of MAFLD. Of the five indices, FLI was the best at predicting MAFLD, with the highest AUROC (0.791). The sensitivity and specificity of FLI for diagnosing MAFLD were both 70.9%. The optimal cut-off value was 29.9. FLI is a useful surrogate index for screening MAFLD in clinical practice.

Levels of abdominal adipose tissue and metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 years: the CARDIA Study

BACKGROUND

Higher levels of intra-abdominal adipose tissue (IAAT) comprising visceral adipose tissue (VAT), intermuscular adipose tissue (IMAT), and liver fat are posited drivers of obesity-related chronic disease risk. Fast food is hypothesized to contribute to IAAT patterns.

OBJECTIVES

We quantified levels of abdominal subcutaneous adipose tissue (SAT), IAAT, and odds of metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 y.

METHODS

We analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants underwent 6 clinical exams and measurements over 25 y with computed tomography-measured VAT, SAT, and IMAT (n = 3156), plus MAFLD defined by liver attenuation (≤40 Hounsfield units) and 1 metabolic abnormality at year 25 (2010, n = 3001, n cases = 302). We estimated means of VAT, SAT, IMAT, and liver attenuation at the year 25 exam according to categories of average fast-food intake over the previous 25 y adjusted for sociodemographic and lifestyle factors and logistic regression to estimate the odds ratio of MAFLD at year 25.

RESULTS

With higher average fast-food intake over 25 y (categorized as follows: never-1×/mo, >1×-3×/mo, 1-<2×/wk, 2-<3×/wk, ≥3×/wk), there were monotonic higher levels of VAT (98.5, 127.6, 134.5, 142.0, 145.5 cm3), P-trend < 0.0001, which were consistent across anthropometrically classified obesity categories. There was a similar pattern with liver fat. There were higher levels of IMAT and SAT with higher fast-food intake (P-trend = 0.003, 0.0002, respectively), with amounts leveling off at ≥2×/wk. In addition, compared with participants who ate fast food never-1×/mo, there were monotonic higher odds of having MAFLD at year 25 with higher average fast-food intake, with participants who ate fast food ≥3×/wk having an OR of MAFLD = 5.18 (95% CI: 2.87, 9.37).

CONCLUSIONS

There were monotonic higher levels of VAT, liver fat, and odds of having MAFLD in middle age according to higher average fast-food intake over the preceding 25 y.

Nonalcoholic Fatty Liver Disease and Cardiovascular Risk: A Scientific Statement From the American Heart Association

Nonalcoholic fatty liver disease (NAFLD) is an increasingly common condition that is believed to affect >25% of adults worldwide. Unless specific testing is done to identify NAFLD, the condition is typically silent until advanced and potentially irreversible liver impairment occurs. For this reason, the majority of patients with NAFLD are unaware of having this serious condition. Hepatic complications from NAFLD include nonalcoholic steatohepatitis, hepatic cirrhosis, and hepatocellular carcinoma. In addition to these serious complications, NAFLD is a risk factor for atherosclerotic cardiovascular disease, which is the principal cause of death in patients with NAFLD. Accordingly, the purpose of this scientific statement is to review the underlying risk factors and pathophysiology of NAFLD, the associations with atherosclerotic cardiovascular disease, diagnostic and screening strategies, and potential interventions.

Prevalence and clinical significance of portal inflammation, portal plasma cells, interface hepatitis and biliary injury in liver biopsies from patients with non-alcoholic steatohepatitis

The significance of portal tract histological changes in non-alcoholic fatty liver disease (NAFLD) remains unclear. In 2019, CymaBay Therapeutics halted clinical trials of seladelpar (a PPARδ agonist) because initial end-of-treatment liver biopsies of patients with non-alcoholic steatohepatitis (NASH) showed concerning features of portal inflammation with plasma cells, interface hepatitis and focal bile duct abnormalities. Adjudication concluded that these findings were present in the initial, as well as the subsequent biopsies. Thus, this study's aim was to determine the prevalence and clinical significance of portal inflammation, portal plasma cells, interface hepatitis and features of bile duct damage in liver biopsies of adult patients with NAFLD. The pathology database was searched for cases of NAFLD, including steatosis alone and NASH, from January 2016 to October 2020. Liver biopsies were selected from age and sex matched adult patients with diagnoses of steatosis alone (n=10), NASH fibrosis stage 1 (n=10), stage 2 (n=10), stage 3 (n=10), and stage 4 (n=10). There were 24 males and 26 females with a mean age of 48 years (range 20-79). Exclusion criteria included age <18 years, daily alcohol intake >14 drinks per week, elevation of alkaline phosphatase level, comorbid chronic liver disease, or liver biopsy performed as part of a clinical trial for NASH. Control liver biopsies were selected from age and sex matched persons without significant steatosis and normal liver biochemical tests (n=10). Histological parameters were evaluated in 10 portal tracts or 10 septal areas in each liver biopsy. Portal inflammation and interface hepatitis were graded on a scale of 0-4. Portal plasma cells and bile duct damage were scored from 0-3. Ductular proliferation was assessed by CK7 immunostain and graded from 0-4. NASH biopsies with advanced fibrosis (stage 3 and 4) showed portal inflammatory infiltrates (score 2-3) with readily identifiable plasma cells (score 2), and mild to moderate interface hepatitis (score 2-3). All cases and controls showed focal, mild cholangiocyte changes, characterised by cytoplasmic vacuolation, segmental loss of nuclei, nuclear disarray and apoptosis. NASH patients with advanced fibrosis had frequent and diffuse cholangiocyte changes, along with focal lymphocytic cholangitis and moderate to marked ductular reaction (score 3-4). Histopathological features of advanced NASH frequently include increased portal inflammation with plasma cells, interface hepatitis, cholangiocyte injury and prominent ductular reaction.

Highly Sensitive Two-Photon Lipid Droplet Tracker for In Vivo Screening of Drug Induced Liver Injury

Lipid droplets (LDs) are lipid-abundant organelles found in most cell lines and primarily consist of neutral lipids. They serve as a repository of various lipids and are associated with many cellular metabolic processes, including energy storage, membrane synthesis, and protein homeostasis. LDs are prominent in a variety of diseases related to lipid regulation, including obesity, fatty liver disease, diabetes, and atherosclerosis. To monitor LD dynamics in live samples, we developed a highly selective two-photon fluorescent tracker for LDs (LD1). It exhibited outstanding sensitivity with a remarkable two-photon-action cross section (Φδ_max > 600 GM), photostability, and low cytotoxicity. In human hepatocytes and in vivo mouse liver tissue imaging, LD1 showed very bright fluorescence with high LD selectivity and minimized background signal to evaluate the stages of nonalcoholic fatty liver disease. Interestingly, we demonstrated that the liver sinusoid morphology became narrower with increasing LD size and visualized the dynamics including fusion of the LDs in vivo. Moreover, real-time and dual-color TPM imaging with LD1 and a two-photon lysosome tracker could be a useful predictive screening tool in the drug development process to monitor impending drug-induced liver injury inducing drug candidates.

Nonalcoholic fatty liver disease and its prognosis associates with shorter leucocyte telomeres in a 21-year follow-up study

Leucocyte telomere length (LTL) has been associated with nonalcoholic fatty liver disease (NAFLD), but the evidence is imperfect. Furthermore, liver fibrosis has been shown to correlate with mortality and recent studies have also found associations with LTL and fibrosis suggesting that LTL may have additional prognostic value in liver diseases. Our objective was to study the association of LTL and NAFLD and evaluate the association of LTL in prognosis of NAFLD subjects. Study subjects (n = 847) were middle-aged hypertensive patients. All participants were evaluated for NAFLD and their LTL was measured at baseline. Outcomes were obtained from Finnish Causes-of-Death Register and the Care Register for Health Care in Statistics Finland to the end of 2014. An inverse association with NAFLD prevalence and LTL length was observed (p < .001 for trend). Shortest telomere tertile possessed statistically significantly more NAFLD subjects even with multivariate analysis (shortest vs. middle tertile HR 1.98 p = .006 and shortest vs. longest tertile HR 2.03 p = .007). For the study period, mortality of the study group showed statistically significant relation with telomere length in univariate but not for multivariate analysis. In subgroup analysis, LTL did not associate with prognosis of non-NAFLD subjects. However, LTL was inversely associated with overall mortality in the subjects with NAFLD in both univariate (HR 0.16 p = .007) and multivariate analysis (HR 0.20 p = .045). In middle-aged Caucasian cohort, shorter leucocyte telomeres associated independently with increased prevalence of NAFLD. Shorter LTL was not associated with mortality in non-NAFLD patients whereas it predicted mortality of NAFLD patients independently.

Hepatic Glycogenosis: An Underdiagnosed Entity?

Hepatic glycogenosis (HG) is a rare complication of long-standing poorly controlled type 1 diabetes mellitus (T1DM), which is often misdiagnosed as non-alcoholic fatty liver disease (NAFLD). Despite the existence of several reports in the literature, it still is underrecognized, even among gastroenterologists. Differential diagnosis between these entities is essential since they have different prognoses.

We report a case of an 18-year-old female, with a medical history of poorly controlled T1DM, admitted to an intensive care unit with severe diabetic ketoacidosis (DKA). Upon admission, aminotransferases were significantly elevated; bilirubin and coagulation tests were normal. Despite adequate DKA treatment, she had persistently elevated aminotransferases and hyperlactacidemia. Imaging studies showed hepatomegaly and bright liver parenchyma. Extensive laboratory workup was negative for other causes of liver disease. So, a liver biopsy was performed, which was consistent with the diagnosis of HG. Under strict metabolic control, she had progressive improvement, achieving biochemical normalization within 6 months.

This case highlights the need for clinicians to be aware of this condition due to non-negligible differences between HG and NAFLD, with the latter progressing to fibrosis, and ultimately cirrhosis and hepatocarcinoma. On the opposite, HG is considered a benign condition, associated with an excellent prognosis that can be reversible after adequate metabolic control. Liver biopsy remains the gold standard method for HG diagnosis since it can distinguish it from NAFLD.

The effect of dietary patterns on non-alcoholic fatty liver disease diagnosed by biopsy or magnetic resonance in adults: a systematic review of randomised controlled trials

Adhering to specific dietary patterns might hold promise as a lifestyle modification treatment of non-alcoholic fatty liver disease (NAFLD). The aim of this systematic review was to examine the effect of dietary patterns on changes in hepatic fat content, liver enzymes and metabolic syndrome components. We searched Pubmed, Embase, CINAHL and Web of Science for randomised controlled trials published in English until April 2020, comparing a specific dietary pattern with no treatment, usual care, or a different diet in adults with NAFLD. Studies were included if NAFLD had been diagnosed using biopsy, magnetic resonance imaging, or proton magnetic resonance spectroscopy. Data from three trials in adults with NAFLD but without diabetes (n = 128; mean age 49.9 ± 5.0 years, range 42-55 years) were included in the qualitative synthesis; across them, risk of bias was considered low, unclear and high for 33%, 38% and 29% of domains, respectively. There was moderate evidence that a low-carbohydrate, compared to a low-calorie diet (-27%, P = 0.008, one study, n = 18) and the Mediterranean, compared to a low-fat, high-carbohydrate diet (-4.4%, P = 0.030, one study, n = 12) result in greater reductions in hepatic fat content, but no such evidence was found for the Fatty Liver in Obesity dietary pattern (based on the principles of the Mediterranean diet), compared to the American Heart Association diet (-0.6%, P = 0.706, one study, n = 98). No between-group differences were reported for other outcomes across studies. A post hoc analysis, including two eligible studies assessing the effect of the Mediterranean, compared to a low-fat diet, irrespective of baseline presence of diabetes, showed strong evidence that the Mediterranean diet reduces hepatic fat content (-4.1%, 95% CI = -5.8 to -2.3, P < 0.001; I2 = 0%) and triglyceride concentrations (-16.9 mg/dL, 95% CI = -26.3 to -7.7, P < 0.001; I2 = 0%). Well-designed, adequately powered and rigorous randomised controlled trials are needed to provide robust evidence on the effect of these dietary patterns, but also other whole dietary approaches, on NAFLD progression.

Strategies to Diagnose Nonalcoholic Steatohepatitis: A Novel Approach to Take Advantage of Pharmacokinetic Alterations

Nonalcoholic steatohepatitis (NASH) is the progressive form of nonalcoholic fatty liver disease (NAFLD) and is diagnosed by a liver biopsy. Because of the invasiveness of a biopsy, the majority of patients with NASH are undiagnosed. Additionally, the prevalence of NAFLD and NASH creates the need for a simple screening method to differentiate patients with NAFLD versus NASH. Noninvasive strategies for diagnosing NAFLD versus NASH have been developed, typically relying on imaging techniques and endogenous biomarker panels. However, each technique has limitations, and none can accurately predict the associated functional impairment of drug metabolism and disposition. The function of several drug-metabolizing enzymes and drug transporters has been described in NASH that impacts drug pharmacokinetics. The aim of this review is to give an overview of the existing noninvasive strategies to diagnose NASH and to propose a novel strategy based on altered pharmacokinetics using an exogenous biomarker whose disposition and elimination pathways are directly impacted by disease progression. Altered disposition of safe and relatively inert exogenous compounds may provide the sensitivity and specificity needed to differentiate patients with NAFLD and NASH to facilitate a direct indication of hepatic impairment on drug metabolism and prevent subsequent adverse drug reactions. SIGNIFICANCE STATEMENT: This review provides an overview of the main noninvasive techniques (imaging and panels of biomarkers) used to diagnose NAFLD and NASH along with a biopsy. Pharmacokinetic changes have been identified in NASH, and this review proposes a new approach to predict NASH and the related risk of adverse drug reactions based on the assessment of drug elimination disruption using exogenous biomarkers.

Post-COVID-19 Liver Injury: Comprehensive Imaging With Multiparametric Ultrasound

OBJECTIVES

This study aimed to define patterns of liver injury after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using multiparametric ultrasound (mpUS) in a variable patient population with differing severities of COVID-19.

METHODS

Ninety patients were enrolled into the study: 56 had SARS-CoV-2 3-9 months prior to enrolment; 34 served as a clinically healthy control group. All patients underwent an mpUS evaluation of the liver (elastography, dispersion and attenuation imaging). Seventy-six patients had abdominal magnetic resonance (MR) and noncontrast enhanced thoracic computed tomography (CT) scans performed at the same day. All patients were screened for biochemical markers of liver injury.

RESULTS

Liver elasticity, viscosity, and steatosis values were significantly altered in patients after COVID-19, with particularly higher fibrosis scores compared to the control group (P < .001). Increased biochemical markers of liver injury correlated with changes in mpUS (P < .05), but not with findings on CT or MR findings. Seventeen of 34 hospitalized patients had a moderate or severe course of the disease course with more pronounced changes in mpUS. Increased body mass index was found to influence liver injury and correlated with more severe forms of COVID-19 (P < .001).

CONCLUSIONS

COVID-19 can cause liver injury observable using mpUS. More severe forms of COVID-19 and patient obesity are related to increased values of liver damage observed. In comparison to MRI and CT, mpUS appears to be more sensitive to involvement of liver parenchyma. Further research is warranted to establish this promising method for evaluating post-COVID-19 liver involvement in the aftermath of the pandemic.

SGLT2 Inhibitors as the Most Promising Influencers on the Outcome of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), the most frequent liver disease in the Western world, is a common hepatic manifestation of metabolic syndrome (MetS). A specific cure has not yet been identified, and its treatment is currently based on risk factor therapy. Given that the initial accumulation of triglycerides in the liver parenchyma, in the presence of inflammatory processes, mitochondrial dysfunction, lipotoxicity, glucotoxicity, and oxidative stress, can evolve into non-alcoholic steatohepatitis (NASH). The main goal is to identify the factors contributing to this evolution because, once established, untreated NASH can progress through fibrosis to cirrhosis and, ultimately, be complicated by hepatocellular carcinoma (HCC). Several drugs have been tested in clinical trials for use as specific therapy for NAFLD; most of them are molecules used to cure type 2 diabetes mellitus (T2DM), which is one of the main risk factors for NAFLD. Among the most studied is pioglitazone, either alone or in combination with vitamin E, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors. Actually, the most promising category seems to be sodium-glucose cotransporter (SGLT2) inhibitors. Their action is carried out by inhibiting glucose reabsorption in the proximal renal tubule, leading to its increased excretion in urine and decreased levels in plasma. Experimental studies in animal models have suggested that SGLT2 inhibitors may have beneficial modulatory effects on NAFLD/NASH, and several trials in patients have proven their beneficial effects on liver enzymes, BMI, blood lipids, blood glucose, and insulin resistance in NAFLD patients, thus creating strong expectations for their possible use in preventing the evolution of liver damage in these patients. We will review the main pathogenetic mechanisms, diagnostic modalities, and recent therapies of NAFLD, with particular attention to the use of SGLT2 inhibitors.

Relationship Between Thyroid Hormone and Liver Steatosis Analysis Parameter in Obese Participants: A Case-Control Study

OBJECTIVE

The thyroid hormone has been demonstrated to be associated with nonalcoholic fatty liver disease (NAFLD) in different populations. However, the relationship between thyroid hormone and the degree of liver steatosis in overweight/obese subjects is still unclear. Liver ultra-sound attenuation (LiSA) is a newly developed ultrasound attenuation parameter for the analysis of hepatic steatosis. The study aimed to characterize the relationship between thyroid hormone and LiSA in overweight/obese participants.

METHODS

This case-control study was performed in Ningbo First Hospital, China. A total of 24 lean, 66 overweight and 49 obese participants were consecutively recruited from January 2021 to May 2021. Thyroid hormone and other clinical features were measured. LiSA was acquired by using a Hepatus ultrasound machine. Multiple linear regression analyses were performed to examine associations of LiSA and clinic indices.

RESULTS

Obese subjects had higher LiSA, fT3 and TSH levels than lean participants of similar age and sex (P < 0.05). LiSA was positively associated with the fT3 level. The multiple linear regression analyses showed that fT3 (ß = 0.353, P < 0.001) was independently associated with LiSA in overweight/obese participants.

CONCLUSION

The fT3 level was independently associated with the degree of liver steatosis among the overweight/obese participants.

Prevalence and Predictors of Nonalcoholic Fatty Liver Disease in Family Members of Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease worldwide. Despite the high prevalence, no screening recommendations yet exist. We designed a prospective observational study to estimate the prevalence of NAFLD in the family of patients with NAFLD and develop a predictive model for identifying it.

METHODOLOGY

The prevalence of NAFLD in patients' family members was estimated using ultrasonography, and univariate and multivariate odds were calculated for its predictors. A model was created using the significant parameters on multivariate odds, and its performance was tested using the area under the receiver operating characteristic (AUROC).

RESULTS

Among 447 family members of 191 patients with NAFLD, the prevalence of NAFLD was 55.9%. Family members with NAFLD were younger and had lower serum levels of aspartate aminotransferase, alanine aminotransferase (ALT), triglycerides. The liver stiffness measurement and controlled attenuation parameter values were also lesser in family members compared to the index cases. Age, body mass index (BMI), and ALT were independent predictors of NAFLD in the family members. A model combining age and BMI had an AUROC of 0.838 [95% confidence interval (CI) 0.800-0.876, P < 0.001]. Age ≥30 years and BMI ≥25 kg/m2 had an odds ratio of 33.5 (95% CI 17.0-66.0, P < 0.001) for prediction of NAFLD, in comparison to BMI <25 kg/m2 and age <30 years.

CONCLUSION

Family members of patients with NAFLD are at increased risk of NAFLD. Screening strategies using BMI and age ensure early identification and could be beneficial in clinical practice.

Community Socioeconomic Deprivation Predicts Nonalcoholic Steatohepatitis

In order to determine the relationship between socioeconomic deprivation and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), we retrospectively reviewed the electronic medical records of 1,430 patients in a large tertiary health care network in New York. These patients underwent liver biopsy over a 10-year period and were included in our study if they had evidence of NAFLD/NASH on liver biopsy. Zip codes were used to obtain data necessary to derive the social deprivation index (SDI) from the US Bureau of the Census. The high-SDI group was compared to the low-SDI group. Univariate and multivariate logistic regressions were performed to assess association between socioeconomic factors and NAFLD parameters, including presence of NASH (NAFLD activity score >4), moderate to severe steatosis (>33%), and significant fibrosis (S2-S4). We included 614 patients with NAFLD/NASH; the median SDI was 31.5. Hemoglobin A1c values were higher in the high-SDI group compared to the low-SDI group (6.46 vs. 6.12, P = 0.02). Socioeconomic factors, such as private versus public health care, percentage being foreign born, percentage without a car, percentage with higher needs (<5 years old and >65 years old), and percentage currently living in renter-occupied and crowded housing units, showed statistically significant associations in predicting NASH. After adjusting for patient age, sex, race, body mass index, and diabetes, we saw a significant association between four or more socioeconomic parameters in predicting NASH (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.099-2.856; P = 0.0190) and six or more socioeconomic parameters in predicting severe steatosis (OR, 1.498; 95% CI, 1.031-2.176; P = 0.0338) but no significant correlation between the number of socioeconomic parameters and significant fibrosis. Conclusion: Greater number of socioeconomic determinants (four or more) are associated with greater severity of NASH. Awareness of NAFLD/NASH needs to be raised in communities with high socioeconomic deprivation.

Rodent models and metabolomics in non-alcoholic fatty liver disease: What can we learn?

Non-alcoholic fatty liver disease (NAFLD) prevalence has increased drastically in recent decades, affecting up to 25% of the world’s population. NAFLD is a spectrum of different diseases that starts with asymptomatic steatosis and continues with development of an inflammatory response called steatohepatitis, which can progress to fibrosis. Several molecular and metabolic changes are required for the hepatocyte to finally vary its function; hence a “multiple hit” hypothesis seems a more accurate proposal. Previous studies and current knowledge suggest that in most cases, NAFLD initiates and progresses through most of nine hallmarks of the disease, although the triggers and mechanisms for these can vary widely. The use of animal models remains crucial for understanding the disease and for developing tools based on biological knowledge. Among certain requirements to be met, a good model must imitate certain aspects of the human NAFLD disorder, be reliable and reproducible, have low mortality, and be compatible with a simple and feasible method. Metabolism studies in these models provides a direct reflection of the workings of the cell and may be a useful approach to better understand the initiation and progression of the disease. Metabolomics seems a valid tool for studying metabolic pathways and crosstalk between organs affected in animal models of NAFLD and for the discovery and validation of relevant biomarkers with biological understanding. In this review, we provide a brief introduction to NAFLD hallmarks, the five groups of animal models available for studying NAFLD and the potential role of metabolomics in the study of experimental NAFLD.

Dual-Energy Computed Tomography in Diffuse Liver Diseases

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

Noninvasive estimation of local speed of sound by pulse-echo ultrasound in a rat model of nonalcoholic fatty liver

Objective. Speed of sound has previously been demonstrated to correlate with fat concentration in the liver. However, estimating speed of sound in the liver noninvasively can be biased by the speed of sound of the tissue layers overlying the liver. Here, we demonstrate a noninvasive local speed of sound estimator, which is based on a layered media assumption, that can accurately capture the speed of sound in the liver. We validate the estimator using an obese Zucker rat model of non-alcoholic fatty liver disease and correlate the local speed of sound with liver steatosis.Approach.We estimated the local and global average speed of sound noninvasively in 4 lean Zucker rats fed a normal diet and 16 obese Zucker rats fed a high fat diet for up to 8 weeks. The ground truth speed of sound and fat concentration were measured from the excised liver using established techniques.Main Results. The noninvasive, local speed of sound estimates of the livers were similar in value to their corresponding 'ground truth' measurements, having a slope ± standard error of the regression of 0.82 ± 0.15 (R²= 0.74 andp< 0.001). Measurement of the noninvasive global average speed of sound did not reliably capture the 'ground truth' speed of sound in the liver, having a slope of 0.35 ± 0.07 (R²= 0.74 andp< 0.001). Decreasing local speed of sound was observed with increasing hepatic fat accumulation (approximately -1.7 m s^-1per 1% increase in hepatic fat) and histopathology steatosis grading (approximately -10 to -13 m s^-1per unit increase in steatosis grade). Local speed of sound estimates were highly correlated with steatosis grade, having Pearson and Spearman correlation coefficients both ranging from -0.87 to -0.78. In addition, a lobe-dependent speed of sound in the liver was observed by theex vivomeasurements, with speed of sound differences of up to 25 m s^-1(p< 0.003) observed between lobes in the liver of the same animal.Significance.The findings of this study suggest that local speed of sound estimation has the potential to be used to predict or assist in the measurement of hepatic fat concentration and that the global average speed of sound should be avoided in hepatic fat estimation due to significant bias in the speed of sound estimate.

Quantitative Ultrasound Assessment of Hepatic Steatosis

BACKGROUND/AIMS

Non-alcoholic fatty liver disease (NAFLD) is widespread chronic disease of the live in humans with the prevalence of 30% of the United States population.^1,2 The goal of the study is to validate the performance of quantitative ultrasound algorithms in the assessment of hepatic steatosis in patients with suspected NAFLD.

METHODS

This prospective study enrolled a total of 31 patients with clinical suspicion of NAFLD to receive liver fat measurements by quantitative ultrasound and reference MRI measurements (proton density fat-fraction, PDFF). The following ultrasound (US) parameters based on both raw ultrasound RF (Radio Frequency) data and 2D B-mode images of the liver were analyzed with subsequent correlation with MRI-PDFF: hepatorenal index, acoustic attenuation coefficient, Nakagami coefficient parameter, shear wave viscosity, shear wave dispersion and shear wave elasticity. Ultrasound parameters were also correlated with the presence of hypertension and diabetes.

RESULTS

The mean (± SD) age and body mass index of the patients were 49.03 (± 12.49) and 30.12 (± 6.15), respectively. Of the aforementioned ultrasound parameters, the hepatorenal index and acoustic attenuation coefficient showed a strong correlation with MRI-PDFF derivations of hepatic steatosis, with r-values of 0.829 and 0.765, respectively. None of the remaining US parameters showed strong correlations with PDFF. Significant differences in Nakagami parameters and acoustic attenuation coefficients were found in those patients with and without hypertension.

CONCLUSIONS

Hepatorenal index and acoustic attenuation coefficient correlate well with MRI-PDFF-derived measurements of hepatic steatosis. Quantitative ultrasound is a promising tool for the diagnosis and assessment of patients with NAFLD.

Accuracy of Fibrosis-4 index and non-alcoholic fatty liver disease fibrosis scores in metabolic (dysfunction) associated fatty liver disease according to body mass index: failure in the prediction of advanced fibrosis in lean and morbidly obese individuals

BACKGROUND AND AIM

While non-invasive scores are increasingly being used to screen for advanced fibrosis in metabolic (dysfunction) associated fatty liver disease (MAFLD), the effect of BMI on their clinical utility remains uncertain. This study assessed the usefulness of the Fibrosis-4 index (FIB-4) and the non-alcoholic fatty liver disease fibrosis score (NFS) in lean, overweight, obese, severely obese, and morbidly obese patients with biopsy-proven MAFLD.

METHODS

A total of 560 patients (28 lean, 174 overweight, 229 obese, 89 severely obese, 40 morbidly obese) were included. Diagnostic performances and optimal cut-off values for FIB-4 and NFS were calculated using receiver operating characteristic (ROC) curve analysis.

RESULTS

In both lean and morbidly obese patients with MAFLD, both FIB-4 and NFS failed to discriminate advanced fibrosis. Conversely, both scores showed acceptable diagnostic performances in exclusion of advanced fibrosis in overweight, obese, and severely obese patients. FIB-4 was able to exclude advanced fibrosis with the highest diagnostic accuracy in the subgroup of overweight patients (area under the ROC curve: 0.829, 95% confidence interval: 0.738-0.919).

CONCLUSION

FIB-4 and NFS can confidently be used to exclude advanced fibrosis in overweight, obese, and severely obese patients. However, they do not appear clinically useful in lean and morbidly obese patients.

In Vivo Dynamic Nuclear Polarization Magnetic Resonance Imaging for the Evaluation of Redox-Related Diseases and Theranostics

Significance:In vivo molecular and metabolic imaging is an emerging field in biomedical research that aims to perform noninvasive detection of tissue metabolism in disease states and responses to therapeutic agents. The imbalance in tissue oxidation/reduction (Redox) states is related to the onset and progression of several diseases. Tissue redox metabolism provides biomarkers for early diagnosis and drug treatments. Thus, noninvasive imaging of redox metabolism could be a useful, novel diagnostic tool for diagnosis of redox-related disease and drug discovery. Recent Advances:In vivo dynamic nuclear polarization magnetic resonance imaging (DNP-MRI) is a technique that enables the imaging of free radicals in living animals. DNP enhances the MRI signal by irradiating the target tissue or solution with the free radical molecule's electron paramagnetic resonance frequency before executing pulse sequence of the MRI. In vivo DNP-MRI with redox-sensitive nitroxyl radicals as the DNP redox contrast agent enables the imaging of the redox metabolism on various diseases. Moreover, nitroxyl radicals show antioxidant effects that suppress oxidative stress. Critical Issues: To date, considerable progress has been documented preclinically in the development of animal imaging systems. Here, we review redox imaging of in vivo DNP-MRI with a focus on the recent progress of this system and its uses in patients with redox-related diseases. Future Directions: This technique could have broad applications in the study of other redox-related diseases, such as cancer, inflammation, and neurological disorders, and facilitate the evaluation of treatment response as a theranostic tool. Antioxid. Redox Signal. 36, 172-184.

Triglyceride Glucose-Waist Circumference Is Superior to the Homeostasis Model Assessment of Insulin Resistance in Identifying Nonalcoholic Fatty Liver Disease in Healthy Subjects

The triglyceride glucose (TyG) index has been suggested as a marker for insulin resistance; however, few studies have investigated the clinical implications of markers that combine obesity markers with the TyG index. This study aimed to investigate the associations between non-alcoholic fatty liver disease (NAFLD) and TyG-related markers in healthy subjects in Korea. We enrolled 21,001 asymptomatic participants who underwent hepatic ultrasonography. The homeostasis model assessment of insulin resistance (HOMA-IR), TyG index, TyG-body mass index, and TyG-waist circumference (WC) were subsequently analyzed. NAFLD was diagnosed using hepatic ultrasonography. A multiple logistic regression analysis was performed to evaluate the associations between the quartiles of each parameter and the risk of NAFLD. The increase in the NAFLD risk was most evident when the TyG-WC quartiles were applied; the multivariate-adjusted odds ratios for NAFLD were 4.72 (3.65–6.10), 13.28 (10.23–17.24), and 41.57 (31.66–54.59) in the 2nd, 3rd, and 4th TyG-WC quartiles, respectively, when compared with the lowest quartile. The predictability of the TyG-WC for NAFLD was better than that of the HOMA-IR using the area under the curve. The TyG-WC index was superior to the HOMA-IR for identifying NAFLD in healthy Korean adults, especially in the non-obese population.

Human Genetics to Identify Therapeutic Targets for NAFLD: Challenges and Opportunities

Non-alcoholic fatty liver disease (NAFLD) is a continuous progression of pathophysiologic stages that is challenging to diagnose due to its inherent heterogeneity and poor standardization across a wide variety of diagnostic measures. NAFLD is heritable, and several loci have been robustly associated with various stages of disease. In the past few years, larger genetic association studies using new methodology have identified novel genes associated with NAFLD, some of which have shown therapeutic promise. This mini-review provides an overview of the heterogeneity in NAFLD phenotypes and diagnostic methods, discusses genetic associations in relation to the specific stages for which they were identified, and offers a perspective on the design of future genetic mapping studies to accelerate therapeutic target identification.

Triglyceride glucose-waist to height ratio: a novel and effective marker for identifying hepatic steatosis in individuals with type 2 diabetes mellitus

BACKGROUND

The triglyceride-glucose index (TyG), and TyG-driven parameters incorporating TyG and obesity indices have been proposed as reliable indicators of insulin resistance and its related comorbidities. This study evaluated the effectiveness of these indices in identifying hepatic steatosis in individuals with Type 2 diabetes (T2DM).

METHODS

This was a cross-sectional study consisting of 175 patients with T2DM (122 with and 53 without NAFLD). TyG index, triglyceride glucose-body mass index (TyG-BMI), triglyceride glucose-waist circumference (TyG-WC), and triglyceride glucose-waist-to-height ratio (TyG-WHtR) were determined using standard formulas. Controlled attenuation parameter (CAP) was measured by transient elastography (FibroScan).

RESULTS

Among obesity parameters, CAP showed the strongest correlation with WHtR, followed by BMI and WC (all P < 0.001). Regression analyses demonstrated TyG-WHtR as a significant predictor of NAFLD with the highest odds ratio, reaching 10.69 (95% CI: 1.68-68.22) for the top quartile (Q4) compared to the first quartile (P = 0.01), followed by TyG-BMI (Q4: 6.75; 95% CI: 1.49-30.67) and TyG-WC (Q4: 5.90; 95% CI: 0.99-35.18). Moreover, TyG-WHtR presented the largest AUC for detection of NAFLD (0.783, P < 0.001) in ROC analysis, followed by TyG-BMI (AUC: 0.751, P < 0.001), TyG-WC (AUC: 0.751, P < 0.001), and TyG (AUC: 0.647, P = 0.002). TyG-WHtR value of 5.58 (sensitivity: 79%, specificity: 68%, P < 0.001) was the best cut-off point to identify hepatic steatosis in this population.

CONCLUSIONS

This study confirmed that the TyG-related indices comprising TyG and obesity parameters can identify hepatic steatosis more successfully than TyG alone. Furthermore, our results highlighted TyG-WHtR as a simple and effective marker for screening fatty liver in patients with T2DM, which may be used practically in clinical setting.

Saroglitazar and Hepano treatment offers protection against high fat high fructose diet induced obesity, insulin resistance and steatosis by modulating various class of hepatic and circulating lipids

Higher global prevalence of non-alcoholic fatty liver disease (NAFLD) is associated with obesity, steatosis, and insulin resistance (IR), and often progresses to steatohepatitis (NASH). Even after more than twenty years of research, there is still no FDA approved therapy for the treatment of fatty liver disease/NASH though, Saroglitazar - a dual PPAR α/γ agonist has been recently approved as a therapeutic option for the fatty liver disease in India. Hepatoprotective Ayurvedic formulations are widely used and are considered safe. In the present study, C57BL/6 male mice on HFHF diet for four weeks were treated with vehicle, Saroglitazar (3 mg/kg/po), and Hepano - a formulation of five herbs (200 mg/kg/po), at the human equivalent therapeutic doses for additional eight weeks. These animals were evaluated after 12 weeks for obesity, body mass index (BMI), systemic insulin resistance, hyperglycaemia, dyslipidaemia, and hepatic lipid accumulation. Differential liquid chromatography-mass spectrometry (LC-MS/MS) based lipidomics analysis demonstrated significant changes in the different class of lipids [phospholipids, sphingolipids, diglycerides and triglycerides (TG)] in HFHF fed group. The protective effects of both Saroglitazar and Hepano were evident against IR, obesity and in the modulation of different class of lipids in the circulation and hepatic tissue. Saroglitazar reduced TG as well as modulated phospholipids levels, while Hepano modulated only phospholipids, ceramides, oxidised lipids, and had no effect on hepatic or circulating TG levels in HFHF fed mice. In addition, in vitro studies using HepG2, THP1 and LX2 cells demonstrated safety of both the test substances where Hepano possess better anti-inflammatory as well as anti-fibrotic potential. Overall, Saroglitazar seems to be more efficacious than Hepano in the regimen used against HFHF induced IR, obesity, and dyslipidaemia.

Bariatric Surgery Improves the Atherogenic Profile of Circulating Methylarginines in Obese Patients: Results from a Pilot Study

Bariatric surgery improves obesity-related comorbidities. Methylarginines are biomarkers of cardiometabolic risk, liver steatosis, and insulin resistance. Here, we aimed to investigate methylarginines in obese patients undergoing bariatric surgery and compared them to age- and sex-matched healthy subjects. Thirty-one obese patients who underwent bariatric surgery and 31 healthy individuals were used for this retrospective study. The basal serum methylarginine levels were determined in the healthy individuals and the obese patients, before surgery and 6 and 12 months after surgery, by mass spectrometry. Compared with the healthy individuals, the obese patients displayed elevated monomethylarginine (mean change: +95%, p < 0.001), asymmetric-dimethylarginine (+105%, p < 0.001), symmetric-dimethylarginine (+25%, p = 0.003), and dimethylguanidino valerate (+32%, p = 0.008) concentrations. Bariatric surgery durably reduced the body mass index by 28% (12 months, 95%CI: 24–33, p = 0.002) and improved plasma lipids, insulin resistance, and liver function. Bariatric surgery reduced the serum levels of monomethylarginine and asymmetric-dimethylarginine by 12% (95%CI: 6–17) and 36% (95%CI: 27–45) (12 months, p = 0.003), respectively, but not symmetric-dimethylarginine or dimethylguanidino valerate. The monomethylarginine and asymmetric-dimethylarginine concentrations were strongly correlated with markers of dyslipidemia, insulin resistance, and a fatty liver. Serum dimethylguanidino valerate was primarily correlated with glycemia and renal function, whereas serum symmetric-dimethylarginine was almost exclusively associated with renal function. In conclusion, the monomethylarginine and asymmetric-dimethylarginine levels are efficiently decreased by bariatric surgery, leading to a reduced atherogenic profile in obese patients. Methylarginines follow different metabolic patterns, which could help for the stratification of cardiometabolic disorders in obese patients.

Randomised clinical trial: semaglutide versus placebo reduced liver steatosis but not liver stiffness in subjects with non-alcoholic fatty liver disease assessed by magnetic resonance imaging

BACKGROUND

Glucagon-like peptide-1 receptor agonists may be a treatment option in patients with non-alcoholic fatty liver disease (NAFLD).

AIMS

To investigate the effects of semaglutide on liver stiffness and liver fat in subjects with NAFLD using non-invasive magnetic resonance imaging (MRI) methods.

METHODS

This randomised, double-blind, placebo-controlled trial enrolled subjects with liver stiffness 2.50-4.63 kPa by magnetic resonance elastography (MRE) and liver steatosis ≥10% by MRI proton density fat fraction (MRI-PDFF). The primary endpoint was change from baseline to week 48 in liver stiffness assessed by MRE.

RESULTS

Sixty-seven subjects were randomised to once-daily subcutaneous semaglutide 0.4 mg (n = 34) or placebo (n = 33). Change from baseline in liver stiffness was not significantly different between semaglutide and placebo at week 48 (estimated treatment ratio 0.96 (95% CI 0.89, 1.03; P = 0.2798); significant differences in liver stiffness were not observed at weeks 24 or 72. Reductions in liver steatosis were significantly greater with semaglutide (estimated treatment ratios: 0.70 [0.59, 0.84], P = 0.0002; 0.47 [0.36, 0.60], P < 0.0001; and 0.50 [0.39, 0.66], P < 0.0001) and more subjects achieved a ≥ 30% reduction in liver fat content with semaglutide at weeks 24, 48 and 72, (all P < 0.001). Decreases in liver enzymes, body weight and HbA1c were also observed with semaglutide.

CONCLUSIONS

The change in liver stiffness in subjects with NAFLD was not significantly different between semaglutide and placebo. However, semaglutide significantly reduced liver steatosis compared with placebo which, together with improvements in liver enzymes and metabolic parameters, suggests a positive impact on disease activity and metabolic profile. ClinicalTrials.gov identifier: NCT03357380.

The associations between coronary artery disease, and non-alcoholic fatty liver disease by computed tomography

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is increasing in recognition as a hepatic condition that is unrelated to significant alcoholic consumption, but has rather, been suggested to constitute cardiovascular risk (irrespective of traditional risk factors and high-risk plaque features). Both coronary artery disease and NAFLD share the same pathophysiology and metabolic profile. NAFLD can theoretically be a source/initiator for coronary artery disease (CAD). We aimed to study the association between NAFLD, CAD, the presence of high-risk plaque features, and the severity of stenosis.

RESULTS

We recruited 800 patients with suspected obstructive CAD and planned for coronary computed tomography angiography (CCTA), Exclusion criteria: heavy alcohol consumption; contraindications to contrast media; unevaluated coronary-artery segments; other known liver disease; and use of oral corticosteroids and/or amiodarone. Non-enhanced Computed Tomography abdomen was performed before the CCTA to detect NAFLD. To study the association between NAFLD and the presence of CAD, patients were classified as to either have, or not have CAD. The CAD group were then further studied for the presence of high-risk plaque features: napkin ring sign, Positive remodelling, Low Hounsfield unit (HU), and Spotty calcium; and their association with NAFLD. Thirty-two per cent of patients had NAFLD and 45% had CAD. A significant association between NAFLD and CAD was found (OR 4.21, 95% CI (confidence interval) (2.83-6.25), p = 0.000). In CAD patients, significant associations were present between NAFLD and high-risk plaque features: Napkin ring sign, Positive remodelling, Low HU, and Spotty calcium (OR 7.88, 95% CI (4.39-14.12), p < 0.001, OR 5.84, 95% (3.85-8.85), p < 0.001, OR 7.25, 95% CI (3.31-15.90), p < 0.001 and OR 6.66, 95% CI (3.75-11.82), p < 0.001), respectively. NAFLD was present in 39.30%, 50.00%, 20.00%, 54.50% and 100.00% of patients with CAD; and 1-24%; 25-49%; 50-69%; 7 = 0-99%, LMD (Left Main Disease) > 50% stenosis or 3V disease, and Total occlusion, respectively, p < 0.001.

CONCLUSIONS

NAFLD is strongly associated with CAD, high-risk plaque features and higher grade of stenosis.

Association between hepatic fat and subclinical vascular disease burden in the general population

OBJECTIVE

It is still controversial if increased hepatic fat independently contributes to cardiovascular risk. We aimed to assess the association between hepatic fat quantified by MRI and various subclinical vascular disease parameters.

DESIGN

We included two cross-sectional investigations embedded in two independent population-based studies (Study of Health in Pomerania (SHIP): n=1341; Cooperative Health Research in the Region of Augsburg (KORA): n=386). The participants underwent a whole-body MRI examination. Hepatic fat content was quantified by proton-density fat fraction (PDFF). Aortic diameters in both studies and carotid plaque-related parameters in KORA were measured with MRI. In SHIP, carotid intima-media thickness (cIMT) and plaque were assessed by ultrasound. We used (ordered) logistic or linear regression to assess associations between hepatic fat and subclinical vascular disease.

RESULTS

The prevalence of fatty liver disease (FLD) (PDFF >5.6%) was 35% in SHIP and 43% in KORA. In SHIP, hepatic fat was positively associated with ascending (β, 95% CI 0.06 (0.04 to 0.08)), descending (0.05 (0.04 to 0.07)) and infrarenal (0.02 (0.01 to 0.03)) aortic diameters, as well as with higher odds of plaque presence (OR, 95% CI 1.22 (1.05 to 1.42)) and greater cIMT (β, 95% CI 0.01 (0.004 to 0.02)) in the age-adjusted and sex-adjusted model. However, further adjustment for additional cardiometabolic risk factors, particularly body mass index, attenuated these associations. In KORA, no significant associations were found.

CONCLUSIONS

The relation between hepatic fat and subclinical vascular disease was not independent of overall adiposity. Given the close relation of FLD with cardiometabolic risk factors, people with FLD should still be prioritised for cardiovascular disease screening.

Contemporary strategies to assess and manage liver donor steatosis: a review

PURPOSE OF REVIEW

Due to a persistent shortage of donor livers, attention has turned toward ways of utilizing marginal grafts, particularly those with steatosis, without incurring inferior outcomes. Here we review the evaluation and utilization of steatotic liver allografts, highlight recently published data, and discuss novel methods of graft rehabilitation.

RECENT FINDINGS

Although severe liver allograft (>60%) steatosis has been associated with inferior graft and recipient outcomes, mild (<30%) steatosis has not. There is ongoing debate regarding safe utilization of grafts with moderate (30-60%) steatosis. Presently, no established protocols for evaluating steatosis in donor candidates or utilizing such grafts exist. Liver biopsy is accepted as the gold standard technique, though noninvasive methods have shown promise in accurately predicting steatosis. More recently, machine perfusion has been shown to enhance ex situ liver function and reduce steatosis, emerging as a potential means of optimizing steatotic grafts prior to transplantation.

SUMMARY

Steatotic liver allografts constitute a large proportion of deceased donor organs. Further work is necessary to define safe upper limits for the acceptable degree of steatosis, develop standardized evaluation protocols, and establish utilization guidelines that prioritize safety. Machine perfusion has shown promise in rehabilitating steatotic grafts and offers the possibility of expanding the deceased donor pool.

Quantitative assessment of liver steatosis using ultrasound: dual-energy CT

Reflecting the growing interest in early diagnosis of non-alcoholic fatty liver disease in recent years, the development of noninvasive and reliable fat quantification methods is needed. Dual-energy computed tomography (DE-CT) is a quantitative diagnostic imaging method that estimates the composition of the imaging target using a material decomposition technique based on the X-ray absorption characteristics peculiar to substances from DE-CT scanning using X-rays generated with different energies (tube voltage). In this review article, we first explain the basic principles and technical aspects of DE-CT. Then, we will present the current diagnostic ability of DE-CT and the factors influencing the quantitative evaluation of liver steatosis using DE-CT as compared to multi-modal methods including ultrasound and magnetic resonance imaging-based methods. In brief, DE-CT may have comparable diagnostic performance to the modern US-based liver fat measurement methods. However, the current material decomposition technique using DE-CT does not seem to have added value to the simple quantitative assessment of liver steatosis, because DE-CT measurement does not improve the accuracy of fat quantification over conventional single-energy computed tomography (SE-CT) attenuation. The most significant influencing factor for the quantitative assessment of liver steatosis using DE-CT can be hepatic iron deposition. An iron-specific multi-material decomposition algorithm correcting for the influences of iron in the liver has been under development. The current material decomposition algorithm can still have added value in a specific situation such as the quantitative assessment of liver steatosis using contrast-enhanced DE-CT. However, there is a lack of evidence for the influence of liver fibrosis in the quantitative assessment of liver steatosis using DE-CT.

Evaluation of Adjuvant Chemotherapy-Associated Steatosis (CAS) in Colorectal Cancer

Chemotherapy-associated steatosis is poorly understood in the context of colorectal cancer. In this study, Stage II–III colorectal cancer patients were retrospectively selected to evaluate the frequency of chemotherapy-associated steatosis and to determine whether patients on statins throughout adjuvant chemotherapy develop chemotherapy-associated steatosis at a lower frequency. Baseline and incident steatosis for up to one year from chemotherapy start date was assessed based on radiology. Of 269 patients, 76 (28.3%) had steatosis at baseline. Of the remaining 193 cases, patients receiving adjuvant chemotherapy (n = 135) had 1.57 (95% confidence interval [CI], 0.89 to 2.79) times the adjusted risk of developing steatosis compared to patients not receiving chemotherapy (n = 58). Among patients who underwent chemotherapy, those using statins for pre-existing hyperlipidemia (n = 37) had 0.71 (95% CI, 0.10 to 2.75) times the risk of developing steatosis compared to patients who were not prevalent users of statins (n = 98). Chemotherapeutic treatment of Stage II–III colorectal cancer appears to be consistent with a moderately increased risk of steatosis, although larger studies are necessary to assess the significance of this observation. Prospective trials should be considered to further explore the potential for protective use of statins in this curative patient population.

Liver Fibrosis Assessment

Early diagnosis of hepatic fibrosis (HF) is pivotal for management to cease progression to cirrhosis and hepatocellular carcinoma. HF is the telltale sign of chronic liver disease, and confirmed by liver biopsy, which is an invasive technique and inclined to sampling errors. The morphologic parameters of cirrhosis are assessed on conventional imaging such as on ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI). Newer imaging modalities such as magnetic resonance elastography and US elastography are reliable and accurate. More research studies on novel imaging modalities such as MRI with diffusion weighted imaging, enhancement by hepatobiliary contrast agents, and CT using perfusion are essential for earlier diagnosis, surveillance and accurate management. The purpose of this article is to discuss non-invasive CT, MRI, and US imaging modalities for diagnosis and stratify HF.

Multifocus Thermal Strain Imaging Using a Curved Linear Array Transducer for Identification of Lipids in Deep Tissue

Thermal strain imaging (TSI) is an ultrasound-based imaging technique intended primarily for diseases in which lipid accumulation is the main biomarker. The goal of the research described here was to successfully implement TSI on a single, commercially available curved linear array transducer for heating and imaging of organs at a deeper depth. For an effective temperature rise of the tissue over a large area, which is key to TSI performance, an innovative multifocus beamforming approach was applied. This yielded a heating area from 32 to 96 mm in the axial direction and -7 to +7 mm in the lateral direction. The pressure fields generated from simulation were in agreement with pressure fields measured with the hydrophone. TSI with safe acoustic power identified with high contrast a rubber inclusion and liposuction fat tissue embedded in a gelatin block.

Plasma and stool metabolomics to identify microbiota derived-biomarkers of metabolic dysfunction-associated fatty liver disease: effect of PNPLA3 genotype

INTRODUCTION

Non-invasive biomarkers are needed for metabolic dysfunction-associated fatty liver disease (MAFLD), especially for patients at risk of disease progression in high-prevalence areas. The microbiota and its metabolites represent a niche for MAFLD biomarker discovery. However, studies are not reproducible as the microbiota is variable.

OBJECTIVES

We aimed to identify microbiota-derived metabolomic biomarkers that may contribute to the higher MAFLD prevalence and different disease severity in Latin America, where data is scarce.

METHODS

We compared the plasma and stool metabolomes, gene patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 single nucleotide polymorphism (SNP), diet, demographic and clinical data of 33 patients (12 simple steatosis and 21 steatohepatitis) and 19 healthy volunteers (HV). The potential predictive utility of the identified biomarkers for MAFLD diagnosis and progression was evaluated by logistic regression modelling and ROC curves.

RESULTS

Twenty-four (22 in plasma and 2 in stool) out of 424 metabolites differed among groups. Plasma triglyceride (TG) levels were higher among MAFLD patients, whereas plasma phosphatidylcholine (PC) and lysoPC levels were lower among HV. The PNPLA3 risk genotype was related to higher plasma levels of eicosenoic acid or fatty acid 20:1 (FA(20:1)). Body mass index and plasma levels of PCaaC24:0, FA(20:1) and TG (16:1_34:1) showed the best AUROC for MAFLD diagnosis, whereas steatosis and steatohepatitis could be discriminated with plasma levels of PCaaC24:0 and PCaeC40:1.

CONCLUSION

This study identified for the first time MAFLD potential non-invasive biomarkers in a Latin American population. The association of PNPLA3 genotype with FA(20:1) suggests a novel metabolic pathway influencing MAFLD pathogenesis.