Liver stiffness measurement in non-alcoholic fatty liver disease: Two is better than one

Predicting Non-Alcoholic Steatohepatitis: A Lipidomics-Driven Machine Learning Approach

Nonalcoholic fatty liver disease (NAFLD), nowadays the most prevalent chronic liver disease in Western countries, is characterized by a variable phenotype ranging from steatosis to nonalcoholic steatohepatitis (NASH). Intracellular lipid accumulation is considered the hallmark of NAFLD and is associated with lipotoxicity and inflammation, as well as increased oxidative stress levels. In this study, a lipidomic approach was used to investigate the plasma lipidome of 12 NASH patients, 10 Nonalcoholic Fatty Liver (NAFL) patients, and 15 healthy controls, revealing significant alterations in lipid classes, such as glycerolipids and glycerophospholipids, as well as fatty acid compositions in the context of steatosis and steatohepatitis. A machine learning XGBoost algorithm identified a panel of 15 plasma biomarkers, including HOMA-IR, BMI, platelets count, LDL-c, ferritin, AST, FA 12:0, FA 18:3 ω3, FA 20:4 ω6/FA 20:5 ω3, CAR 4:0, LPC 20:4, LPC O-16:1, LPE 18:0, DG 18:1_18:2, and CE 20:4 for predicting steatohepatitis. This research offers insights into the connection between imbalanced lipid metabolism and the formation and progression of NAFL D, while also supporting previous research findings. Future studies on lipid metabolism could lead to new therapeutic approaches and enhanced risk assessment methods, as the shift from isolated steatosis to NASH is currently poorly understood.

AGA Clinical Practice Update on the Role of Noninvasive Biomarkers in the Evaluation and Management of Nonalcoholic Fatty Liver Disease: Expert Review

DESCRIPTION

The purpose of this American Gastroenterological Association (AGA) Clinical Practice Update Expert Review is to provide clinicians with guidance on the use of noninvasive tests (NITs) in the evaluation and management of patients with nonalcoholic fatty liver disease (NAFLD). NAFLD affects nearly 30% of the global population and is a growing cause of end-stage liver disease and liver-related health care resource utilization. However, only a minority of all patients with NAFLD experience a liver-related outcome. It is therefore critically important for clinicians to assess prognosis and identify those with increased risk of disease progression and negative clinical outcomes at the time of initial assessment. It is equally important to assess disease trajectory over time, particularly in response to currently available therapeutic approaches. The reference standard for assessment of prognosis and disease monitoring is histologic examination of liver biopsy specimens. There are, however, many limitations of liver biopsies and their reading that have limited their use in routine practice. The utilization of NITs facilitates risk stratification of patients and longitudinal assessment of disease progression for patients with NAFLD. This clinical update provides best practice advice based on a review of the literature on the utilization of NITs in the management of NAFLD for clinicians. Accordingly, a combination of available evidence and consensus-based expert opinion, without formal rating of the strength and quality of the evidence, was used to develop these best practice advice statements.

METHODS

This Expert Review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. These best practice advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these best practice advice statements do not carry formal ratings of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: NITs can be used for risk stratification in the diagnostic evaluation of patients with NAFLD. BEST PRACTICE ADVICE 2: A Fibrosis 4 Index score <1.3 is associated with strong negative predictive value for advanced hepatic fibrosis and may be useful for exclusion of advanced hepatic fibrosis in patients with NAFLD. BEST PRACTICE ADVICE 3: A combination of 2 or more NITs combining serum biomarkers and/or imaging-based biomarkers is preferred for staging and risk stratification of patients with NAFLD whose Fibrosis 4 Index score is >1.3. BEST PRACTICE ADVICE 4: Use of NITs in accordance with manufacturer's specifications (eg, not in patients with ascites or pacemakers) can minimize risk of discordant results and adverse events. BEST PRACTICE ADVICE 5: NITs should be interpreted with context and consideration of pertinent clinical data (eg, physical examination, biochemical, radiographic, and endoscopic) to optimize positive predictive value in the identification of patients with advanced fibrosis. BEST PRACTICE ADVICE 6: Liver biopsy should be considered for patients with NIT results that are indeterminate or discordant; conflict with other clinical, laboratory, or radiologic findings; or when alternative etiologies for liver disease are suspected. BEST PRACTICE ADVICE 7: Serial longitudinal monitoring using NITs for assessment of disease progression or regression may inform clinical management (ie, response to lifestyle modification or therapeutic intervention). BEST PRACTICE ADVICE 8: Patients with NAFLD and NITs results suggestive of advanced fibrosis (F3) or cirrhosis (F4) should be considered for surveillance of liver complications (eg, hepatocellular carcinoma screening and variceal screening per Baveno criteria). Patients with NAFLD and NITs suggestive of advanced hepatic fibrosis (F3) or (F4), should be monitored with serial liver stiffness measurement; vibration controlled transient elastography; or magnetic resonance elastography, given its correlation with clinically significant portal hypertension and clinical decompensation.

Reduced and more appropriate referrals of patients with type 2 diabetes using liver stiffness measurement compared to FIB-4

BACKGROUND

Fatty liver disease and fibrosis are common in patients with type 2 diabetes mellitus (T2DM). Recently published European Association for the Study of the Liver guidelines have suggested screening such patients using liver stiffness measurement (LSM) or fibrosis-4 index (FIB-4) to exclude advanced fibrosis.

AIMS

We initiated a screening programme at the diabetes out-patient clinic to assess the reliability of the suggested approaches and resulting referrals.

METHODS

In this prospective study, consecutive patients attending for T2DM review at an Irish level 3 (district general) hospital between September and November 2021 were screened for liver fibrosis using LSM and had their FIB-4 calculated. The first 100 patients with valid LSM measurements were included in the analysis.

RESULTS

Referral rates to the hepatology clinic varied by modality used. If FIB-4 ≥ 1.3 criterion was used, the referral rate to the hepatology clinic was 45%; using LSM < 8 kPa to rule out advanced fibrosis resulted in 34% referral rate; using LSM ≥ 10 kPa to suggest probable compensated advanced chronic liver disease reduced referral rates to 15%. Combining FIB-4 with LSM in a two-step algorithm led to missed potentially significant liver disease in large numbers. 47% patients with LSM ≥ 8 kPa and 33% with LSM ≥ 10 kPa had FIB-4 < 1.3.

CONCLUSIONS

Screening of patients with T2DM using LSM alone rather than FIB-4 leads to reduced numbers of, and more appropriate, referrals to the hepatology clinic. Shifting from an exclusion (LSM < 8 kPa) to an inclusion based (LSM ≥ 10 kPa) approach may lessen the potential of screening to overwhelm hepatology services.

Vibration-controlled Transient Elastography for Assessment of Liver Fibrosis at a USA Academic Medical Center

BACKGROUND AND AIMS

Vibration-controlled transient elastography (VCTE) is a noninvasive tool that uses liver stiffness measurement (LSM) to assess fibrosis. Since real-life data during everyday clinical practice in the USA are lacking, we describe the patterns of use and diagnostic performance of VCTE in patients at an academic medical center in New York City.

METHODS

Patients who received VCTE scans were included if liver biopsy was performed within 1 year. Diagnostic performance of VCTE in differentiating dichotomized fibrosis stages was assessed via area under the receiver operating characteristics (AUROC). Fibrosis stage determined from VCTE LSM was compared to liver biopsy.

RESULTS

Of 109 patients, 49 had nonalcoholic fatty liver disease, 16 chronic hepatitis C, 15 congestive hepatopathy, and 22 at least two etiologies. AUROC was 0.90 for differentiating cirrhosis (stage 4) with a positive predictive value (PPV) range of 0.28 to 0.45 and negative predictive value range of 0.96 to 0.98. For 31 (32%) patients, VCTE fibrosis stage was at least two stages higher than liver biopsy fibrosis stage. Thirteen of thirty-five patients considered to have cirrhosis by VCTE had stage 0 to 2 and 12 stage 3 fibrosis on liver biopsy.

CONCLUSIONS

VCTE has reasonable diagnostic accuracy and is reliable at ruling out cirrhosis. However, because of its low PPV, caution must be exercised when used to diagnose cirrhosis, as misdiagnosis can lead to unnecessary health care interventions. In routine practice, VTCE is also sometimes performed for disease etiologies for which it has not been robustly validated.

Comparative analysis of metabolic risk factors for progression of non-alcoholic fatty liver disease

Aim of the study

Non-alcoholic fatty liver disease (NAFLD), a globally prevailing chronic liver condition, refers to a spectrum of disease ranging from bland steatosis to steatohepatitis causing fibrosis without significant alcohol intake. Prominent risk factors (RFs) include obesity, type 2 diabetes mellitus, and dyslipidemia. Currently, no established hierarchy exists for the influence of metabolic RFs on NAFLD progression. This retrospective cohort study investigated and ranked the independent and combined effects of three major RFs on NAFLD progression.

Material and methods

652 NAFLD patients with ≥ 1 RF were categorized by RF combination to examine yearly changes in RF severity with liver stiffness measurement (LSM) over five years. Body mass index (BMI), hemoglo- bin A_1c (HbA_1c), total cholesterol (TC), and LSM were reviewed.

Results

In patients with any single improving RF, decreases in BMI were associated with a yearly LSM change of –1.26 kPa, while decreases in HbA_1c and TC were associated with a change of –0.51 kPa and –0.56 kPa, respectively. In patients with any single worsening RF, increases in BMI were correlated with an LSM change of +0.74 kPa and increases in HbA_1c and T_C were correlated with a change of +0.43 kPa and +0.16 kPa, respectively. Patients with three RFs had the greatest LSM changes for both improving (–3.68 kPa) and worsening (+3.19 kPa) groups. The strongest predictors for LSM change were BMI and HbA_1c, with standardized β coefficients of 0.236 and 0.226 (p < 0.001), while TC had the least influence [0.112 (p < 0.01), F(3,647) = 11.458, p < 0.001, R² = 0.155].

Conclusions

Obesity was the most prominent RF. Treatment of all three RFs over a five-year period presented a high likelihood of fibrosis stage regression for NAFLD patients.

Ultrasound Elastography-Cornerstone of Non-Invasive Metabolic Dysfunction-Associated Fatty Liver Disease Assessment

Metabolic dysfunction-associated fatty liver disease has become the most common chronic liver disease as well as the most common cause for liver transplantation. With its different methods types, elastography of the liver can be used for non-invasive evaluation of the liver fibrosis and steatosis degree. The article focuses on the description, use, advantages, and limitations of the currently known elastographic techniques. It proposes a simple risk assessment algorithm for the liver fibrosis progress evaluation. The following is an overview of the use of liver and spleen elastography in the detection of clinically relevant portal hypertension. It concludes with research and technological possibilities that could be important to the field in the upcoming years.

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

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