Noninvasive Tests in the Assessment of NASH and NAFLD Fibrosis: Now and Into the Future

Plasma ALS and Gal-3BP differentiate early from advanced liver fibrosis in MASLD patients

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is estimated to affect 30% of the world's population, and its prevalence is increasing in line with obesity. Liver fibrosis is closely related to mortality, making it the most important clinical parameter for MASLD. It is currently assessed by liver biopsy - an invasive procedure that has some limitations. There is thus an urgent need for a reliable non-invasive means to diagnose earlier MASLD stages.

METHODS

A discovery study was performed on 158 plasma samples from histologically-characterised MASLD patients using mass spectrometry (MS)-based quantitative proteomics. Differentially abundant proteins were selected for verification by ELISA in the same cohort. They were subsequently validated in an independent MASLD cohort (n = 200).

RESULTS

From the 72 proteins differentially abundant between patients with early (F0-2) and advanced fibrosis (F3-4), we selected Insulin-like growth factor-binding protein complex acid labile subunit (ALS) and Galectin-3-binding protein (Gal-3BP) for further study. In our validation cohort, AUROCs with 95% CIs of 0.744 [0.673 - 0.816] and 0.735 [0.661 - 0.81] were obtained for ALS and Gal-3BP, respectively. Combining ALS and Gal-3BP improved the assessment of advanced liver fibrosis, giving an AUROC of 0.796 [0.731. 0.862]. The {ALS; Gal-3BP} model surpassed classic fibrosis panels in predicting advanced liver fibrosis.

CONCLUSIONS

Further investigations with complementary cohorts will be needed to confirm the usefulness of ALS and Gal-3BP individually and in combination with other biomarkers for diagnosis of liver fibrosis. With the availability of ELISA assays, these findings could be rapidly clinically translated, providing direct benefits for patients.

Metabolic disorders affecting the liver and heart: Therapeutic efficacy of miRNA-based therapies?

Liver and heart disease are major causes of death worldwide. It is known that metabolic alteration causing type 2 diabetes (T2D) and Nonalcoholic fatty liver (NAFLD) coupled with a derangement in lipid homeostasis, may exacerbate hepatic and cardiovascular diseases. Some pharmacological treatments can mitigate organ dysfunctions but the important side effects limit their efficacy leading often to deterioration of the tissues. It needs to develop new personalized treatment approaches and recent progresses of engineered RNA molecules are becoming increasingly viable as alternative treatments. This review outlines the current use of antisense oligonucleotides (ASOs), RNA interference (RNAi) and RNA genome editing as treatment for rare metabolic disorders. However, the potential for small non-coding RNAs to serve as therapeutic agents for liver and heart diseases is yet to be fully explored. Although miRNAs are recognized as biomarkers for many diseases, they are also capable of serving as drugs for medical intervention; several clinical trials are testing miRNAs as therapeutics for type 2 diabetes, nonalcoholic fatty liver as well as cardiac diseases. Recent advances in RNA-based therapeutics may potentially facilitate a novel application of miRNAs as agents and as druggable targets. In this work, we sought to summarize the advancement and advantages of miRNA selective therapy when compared to conventional drugs. In particular, we sought to emphasise druggable miRNAs, over ASOs or other RNA therapeutics or conventional drugs. Finally, we sought to address research questions related to efficacy, side-effects, and range of use of RNA therapeutics. Additionally, we covered hurdles and examined recent advances in the use of miRNA-based RNA therapy in metabolic disorders such as diabetes, liver, and heart diseases.

Understanding NAFLD: From Case Identification to Interventions, Outcomes, and Future Perspectives

While non-alcoholic fatty liver disease (NAFLD) is a prevalent and frequent cause of liver-related morbidity and mortality, it is also strongly associated with cardiovascular disease-related morbidity and mortality, likely driven by its associations with insulin resistance and other manifestations of metabolic dysregulation. However, few satisfactory pharmacological treatments are available for NAFLD due in part to its complex pathophysiology, and challenges remain in stratifying individual patient's risk for liver and cardiovascular disease related outcomes. In this review, we describe the development and progression of NAFLD, including its pathophysiology and outcomes. We also describe different tools for identifying patients with NAFLD who are most at risk of liver-related and cardiovascular-related complications, as well as current and emerging treatment options, and future directions for research.

Evaluation of MACK-3 parameters, metabolic and fibrotic characteristics of non-alcoholic fatty liver disease patients with hypertension

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is an inflammatory subtype of non-alcoholic fatty liver disease (NAFLD) and recent non-invasive test, MACK-3, demonstrated good diagnostic characteristics for fibrosis in several studies. The aim of our study was to assess the liver state using the non-invasive MACK-3 Test, and its link with liver fibrosis stage, inflammatory activity, steatosis, and metabolic markers in NAFLD patients with hypertension (HT).

METHODS

Thirty adult NAFLD patients with HT, aged 30 to 60 years (mean age 46.36±5.1 years) were included in our study. The control group consisted of 20 healthy volunteers. In addition to basic laboratory tests and ultrasonographic examination, validated non-invasive fibrosis test were performed. MACK-3 was calculated using the online calculator with the following variables: fasting glucose, fasting insulin, aspartate aminotransferase (AST) and cytokeratin 18 (CK18).

RESULTS

All NAFLD patients with HT were characterized with increased liver enzymatic activity, lipid profile, increased levels of insulin and HOMA-IR˂0.001. MACK-3 parameters were positively correlated with thymol test = 0.45 (P<0.013), with aspartataminotransferase (AST) = 0.38 (P<0.03) and alanineaminotransferase (ALT) - =0.38 (P<0.03), with the stage of Fibrotest activity = 0.25 (P<0.018) and steatosis = 0.76 (P<0.001).

CONCLUSIONS

MACK-3 parameters associations with hepatic enzymatic activity, steatosis and activity stage suggest this test as a promising for screening use in such patients and requires further studies.

Clinical Model for the Prediction of Severe Liver Fibrosis in Adult Patients with Type II Diabetes Mellitus

Background and Objectives: Non-alcoholic fatty liver disease (NAFLD)-related severe liver fibrosis is associated with a higher risk of progressing to decompensated cirrhosis and hepatic failure and developing NAFLD-related hepatocellular carcinoma (HCC), particularly in populations with diabetes. Our pilot study aims to evaluate the performances of various noninvasive methods in predicting liver fibrosis in a population of patients with diabetes and to establish a new scoring system for the prediction of severe fibrosis (>F3). Materials and Methods: A total of 175 patients with diabetes were enrolled for liver fibrosis evaluation. Using the degree of agreement (concordance) between a noninvasive score based on serum biomarkers (NAFLD fibrosis score) and point shear-wave elastography (pSWE) as the reference method, we generated receiver operating characteristic (ROC) curves and performed a multivariate analysis to predict severe liver fibrosis. Results: In our population of patients with diabetes, gamma-glutamyltransferase (GGT), age, body mass index (BMI), the homeostatic model assessment of insulin resistance (HOMA-IR), and glycosylated hemoglobin (HbA1C) were significant predictors for the diagnosis of the F3/F4 group (area under the ROC: 0.767, 0.743, 0.757, 0.772, and 0.7, respectively; p < 0.005 for all). Moreover, the combined composite score (the sum of GGT, age, BMI, HOMA index, and HbA1C) had the highest diagnostic performance at a cut-off value of 3 (AUROC—0.899; p < 0001). The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 91.20%, 79%, 79%, and 89%, respectively, and 89% of patients were correctly classified as having severe liver fibrosis. In contrast with the Fibrosis 4 (FIB-4) score and the AST-to-platelet ratio index (APRI), the composite score had the best accuracy in discriminating advanced fibrosis. Conclusions: The proposed composite score had a reliable and acceptable diagnostic accuracy in identifying patients with diabetes at risk of having severe fibrosis using readily available laboratory and clinical data.

Malaysian Society of Gastroenterology and Hepatology consensus statement on metabolic dysfunction-associated fatty liver disease

The Malaysian Society of Gastroenterology and Hepatology saw the need for a consensus statement on metabolic dysfunction-associated fatty liver disease (MAFLD). The consensus panel consisted of experts in the field of gastroenterology/hepatology, endocrinology, bariatric surgery, family medicine, and public health. A modified Delphi process was used to prepare the consensus statements. The panel recognized the high and increasing prevalence of the disease and the consequent anticipated increase in liver-related complications and mortality. Cardiovascular disease is the leading cause of mortality in MAFLD patients; therefore, cardiovascular disease risk assessment and management is important. A simple and clear liver assessment and referral pathway was agreed upon, so that patients with more severe MAFLD can be linked to gastroenterology/hepatology care, while patients with less severe MAFLD can remain in primary care or endocrinology, where they are best managed. Lifestyle intervention is the cornerstone in the management of MAFLD. The panel provided a consensus on the use of statin, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, sodium-glucose cotransporter-2 inhibitor, glucagon-like peptide-1 agonist, pioglitazone, vitamin E, and metformin, as well as recommendations on bariatric surgery, screening for gastroesophageal varices and hepatocellular carcinoma, and liver transplantation in MAFLD patients. Increasing the awareness and knowledge of the various stakeholders on MAFLD and incorporating MAFLD into existing noncommunicable disease-related programs and activities are important steps to tackle the disease. These consensus statements will serve as a guide on MAFLD for clinicians and other stakeholders.

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

BACKGROUND AND AIMS

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

APPROACH AND RESULTS

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

CONCLUSIONS

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

MAFLD/NAFLD Biopsy-Free Scoring Systems for Hepatic Steatosis, NASH, and Fibrosis Diagnosis

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is the most prevalent liver disorder worldwide. Historically, its diagnosis required biopsy, even though the procedure has a variable degree of error. Therefore, new non-invasive strategies are needed. Consequently, this article presents a thorough review of biopsy-free scoring systems proposed for the diagnosis of MAFLD. Similarly, it compares the severity of the disease, ranging from hepatic steatosis (HS) and nonalcoholic steatohepatitis (NASH) to fibrosis, by contrasting the corresponding serum markers, clinical associations, and performance metrics of these biopsy-free scoring systems. In this regard, defining MAFLD in conjunction with non-invasive tests can accurately identify patients with fatty liver at risk of fibrosis and its complications. Nonetheless, several biopsy-free scoring systems have been assessed only in certain cohorts; thus, further validation studies in different populations are required, with adjustment for variables, such as body mass index (BMI), clinical settings, concomitant diseases, and ethnic backgrounds. Hence, comprehensive studies on the effects of age, morbid obesity, and prevalence of MAFLD and advanced fibrosis in the target population are required. Nevertheless, the current clinical practice is urged to incorporate biopsy-free scoring systems that demonstrate adequate performance metrics for the accurate detection of patients with MAFLD and underlying conditions or those with contraindications of biopsy.

Insights into Nonalcoholic Fatty-Liver Disease Heterogeneity

The acronym nonalcoholic fatty-liver disease (NAFLD) groups a heterogeneous patient population. Although in many patients the primary driver is metabolic dysfunction, a complex and dynamic interaction of different factors (i.e., sex, presence of one or more genetic variants, coexistence of different comorbidities, diverse microbiota composition, and various degrees of alcohol consumption among others) takes place to determine disease subphenotypes with distinct natural history and prognosis and, eventually, different response to therapy. This review aims to address this topic through the analysis of existing data on the differential contribution of known factors to the pathogenesis and clinical expression of NAFLD, thus determining the different clinical subphenotypes observed in practice. To improve our understanding of NAFLD heterogeneity and the dominant drivers of disease in patient subgroups would predictably impact on the development of more precision-targeted therapies for NAFLD.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: Overlapping Mechanisms

Nonalcoholic fatty liver disease (NAFLD) denotes a condition with excess fat in the liver. The prevalence of NAFLD is increasing, averaging > 25% of the Western population. In 25% of the patients, NAFLD progresses to its more severe form: nonalcoholic steatohepatitis and >25% of these progress to cirrhosis following activation of inflammatory and fibrotic processes. NAFLD is associated with obesity, type 2 diabetes, and the metabolic syndrome and represents a considerable and increasing health burden. In the near future, NAFLD cirrhosis is expected to be the most common cause for liver transplantation. NAFLD patients have an increased risk of developing cardiovascular disease as well as liver-related morbidity. In addition, hepatic steatosis itself appears to represent an independent cardiovascular risk factor. In the present review, we provide an overview of the overlapping mechanisms and prevalence of NAFLD and cardiovascular disease.

Perspectives on Precision Medicine Approaches to NAFLD Diagnosis and Management

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

Making progress in nonalcoholic fatty liver disease (NAFLD) as we are transitioning from the era of NAFLD to dys-metabolism associated fatty liver disease (DAFLD)

• This is a special issue of “Metabolism” dedicated to nonalcoholic fatty liver disease. • Experts in the field provide an overview of recent progress and developments in NAFLD and offer their expert opinion on future directions. • NAFLD remains a highly prevalent disease without an approved treatment.