Prediction of Advanced Fibrosis in Nonalcoholic Fatty Liver Disease: An Enhanced Model of BARD Score

Extracellular vesicle-mediated approaches for the diagnosis and therapy of MASLD: current advances and future prospective

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an asymptomatic, multifaceted condition often associated with various risk factors, including fatigue, obesity, insulin resistance, metabolic syndrome, and sleep apnea. The increasing burden of MASLD underscores the critical need for early diagnosis and effective therapies. Owing to the lack of efficient therapies for MASLD, early diagnosis is crucial. Consequently, noninvasive biomarkers and imaging techniques are essential for analyzing disease risk and play a pivotal role in the global diagnostic process. The use of extracellular vesicles has emerged as promising for early diagnosis and therapy of various liver ailments. Herein, a comprehensive summary of the current diagnostic modalities for MASLD is presented, highlighting their advantages and limitations while exploring the potential of extracellular vesicles (EVs) as innovative diagnostic and therapeutic tools for MASLD. With this aim, this review emphasizes an in-depth understanding of the origin of EVs and the pathophysiological alterations of these ectosomes and exosomes in various liver diseases. This review also explores the therapeutic potential of EVs as key components in the future management of liver disease. The dual role of EVs as biomarkers and their therapeutic utility in MASLD essentially highlights their clinical integration to improve MASLD diagnosis and treatment. While EV-based therapies are still in their early stages of development and require substantial research to increase their therapeutic value before they can be used clinically, the diagnostic application of EVs has been extensively explored. Moving forward, developing diagnostic devices leveraging EVs will be crucial in advancing MASLD diagnosis. Thus, the literature summarized provides suitable grounds for clinicians and researchers to explore EVs for devising diagnostic and treatment strategies for MASLD.

Metabolic dysfunction-associated steatotic liver disease, liver fibrosis and risk of cardiovascular disease: A prospective cohort study

BACKGROUND AND AIMS

In patients with NAFLD, liver fibrosis increases liver-related complications, but there is controversy about the increase in CVD. Based on a prospective cohort study, this study investigated the risk of cardiovascular disease due to liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS AND RESULTS

This study analyzed KCPS-II prospective cohort that tracked 104,399 people who participated in health check-ups at 18 institutions nationwide from 2004 to 2013. If the fatty liver index was 30 or higher, it was defined as SLD, and participants were classified into No-SLD, MASLD, MetALD, ALD, and Cryptogenic SLD. Liver fibrosis was defined by the FIB-4 index, and the occurrence of cardiovascular disease according to SLD classification was analyzed using Cox proportional model regression analysis. Out study included a total of 6,942 participants (6.6%) had MASLD, 6,694 (6.4%) had MetALD, 4,751 (4.6%) had ALD, and 382 (0.3%) had Cryptogenic SLD. For the cases of FIB-4 index ≥1.3, the multivariable-adjusted HR (95% CI) of cardiovascular disease was 2.27 (1.87-2-76) in MASLD, 1.67 (1.30-2.10) in MetALD, and 2.56 (1.99-3.30) in ALD, but it was 0.78 (0.19-3.10) in Cryptogenic_SLD, which was not significant. The risk of cardiovascular disease according to the fibrosis stage classified by BARD also presented similar results.

CONCLUSIONS

This prospective cohort study of Korean patients with newly defined MASLD, MetALD, and ALD with FIB-4 ≥ 1.3 at high risk of developing cardiovascular disease.

Non-invasive evaluation of hepatic macrosteatosis in deceased donors

INTRODUCTION

Liver allocation changes have led to increased travel and expenditures, highlighting the need to efficiently identify marginal livers suitable for transplant. We evaluated the validity of existing non-invasive liver quality tests and a novel machine learning-based model at predicting deceased donor macrosteatosis >30%.

METHODS

We compared previously-validated non-invasive tests and a novel machine learning-based model to biopsies in predicting macrosteatosis >30%. We also tested them in populations enriched for macrosteatosis.

RESULTS

The Hepatic Steatosis Index area-under-the-curve (AUC) was 0.56. At the threshold identified by Youden's J statistic, sensitivity, specificity, positive, and negative predictive values were 49.6%, 58.9%, 14.0%, and 89.7%. Other tests demonstrated comparable results. Machine learning produced the highest AUC (0.71). Even in populations enriched for macrosteatosis, no test was sufficiently predictive.

CONCLUSION

Commonly used clinical scoring systems and a novel machine learning-based model were not clinically useful, highlighting the importance of pre-procurement biopsies to facilitate allocation.

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

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

Surveillance of the progression and assessment of treatment endpoints for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is an aggressive form of nonalcoholic fatty liver disease (NAFLD) characterized by steatosis-associated inflammation and liver injury. Without effective treatment or management, NASH can have life-threatening outcomes. Evaluation and identification of NASH patients at risk for adverse outcomes are therefore important. Key issues in screening NASH patients are the assessment of advanced fibrosis, differentiation of NASH from simple steatosis, and monitoring of dynamic changes during follow-up and treatment. Currently, NASH staging and evaluation of the effectiveness for drugs still rely on pathological diagnosis, despite sample error issues and the subjectivity associated with liver biopsy. Optimizing the pathological assessment of liver biopsy samples and developing noninvasive surrogate methods for accessible, accurate, and safe evaluation are therefore critical. Although noninvasive methods including elastography, serum soluble biomarkers, and combined models have been implemented in the last decade, noninvasive diagnostic measurements are not widely applied in clinical practice. More work remains to be done in establishing cost-effective strategies both for screening for at-risk NASH patients and identifying changes in disease severity. In this review, we summarize the current state of noninvasive methods for detecting steatosis, steatohepatitis, and fibrosis in patients with NASH, and discuss noninvasive assessments for screening at-risk patients with a focus on the characteristics that should be monitored at follow-up.

Fibrosis-4 Index vs Nonalcoholic Fatty Liver Disease Fibrosis Score in Identifying Advanced Fibrosis in Subjects With Nonalcoholic Fatty Liver Disease: A Meta-Analysis

INTRODUCTION

In subjects with nonalcoholic fatty liver disease (NAFLD), advanced fibrosis (AF) carries the highest risk of adverse liver-related events. To reduce the number of unnecessary biopsies, several noninvasive tools (NITs) for the risk stratification of fibrosis have been developed. We conducted this meta-analysis to assess the performance of the fibrosis-4 index (FIB-4) and NAFLD fibrosis scores (NFS), the 2 most common NITs, for the appropriate selection of subjects with AF for biopsy.

METHODS

Four databases were searched until December 2020 (CRD42021224766). Original articles reporting data on the performance of FIB-4 and NFS, interpreted according to standard cutoffs in subjects with biopsy-proven NAFLD, were included. Separate data extractions were performed according to the lower cutoff, the higher cutoff, and the dual threshold approach. The numbers of subjects classified as true-negative, true-positive, false-negative, and false-positive were extracted. Summary operating points were estimated using a random-effects model.

RESULTS

Eighteen studies evaluating 12,604 subjects were included. Participants were adult outpatients with biopsy-proven NAFLD or nonalcoholic steatohepatitis. Overall, a weak-to-moderate performance was found for both scores. The head-to-head comparison showed FIB-4 to be associated with a higher performance in ruling in and NFS in ruling out AF in the single threshold approach, whereas, with the dual threshold approach, a lower prevalence of indeterminate findings was found for FIB-4.

DISCUSSION

This meta-analysis suggested that currently available NITs have a limited performance in identifying AF among subjects with NAFLD. Further studies are needed to optimize existing thresholds or develop new NITs.

Body weight variability and the risk of cardiovascular outcomes in patients with nonalcoholic fatty liver disease

We investigated the association between body weight variability and the risks of cardiovascular disease and mortality in patients with nonalcoholic fatty liver disease (NAFLD) using large-scale, nationwide cohort data. We included 726,736 individuals with NAFLD who underwent a health examination between 2009 and 2010. NAFLD was defined as a fatty liver index ≥ 60, after excluding significant alcohol intake, viral hepatitis, and liver cirrhosis. Body weight variability was assessed using four indices, including variability independent of the mean (VIM). During a median 8.1-year follow-up, we documented 11,358, 14,714, and 22,164 cases of myocardial infarction (MI), stroke, and all-cause mortality, respectively. Body weight variability was associated with an increased risk of MI, stroke, and mortality after adjusting for confounding variables. The hazard ratios (HRs) (95% confidence intervals) for the highest quartile, compared with the lowest quartile, of VIM for body weight were 1.15 (1.10-1.20), 1.22 (1.18-1.26), and 1.56 (1.53-1.62) for MI, stroke, and all-cause mortality, respectively. Body weight variability was associated with increased risks of MI, stroke, and all-cause mortality in NAFLD patients. Appropriate interventions to maintain a stable weight could positively affect health outcomes in NAFLD patients.

Clinical implications of renin-angiotensin system inhibitors for development and progression of non-alcoholic fatty liver disease

Recently, there has been an increasing interest in the therapeutic efficacy of RAS inhibitors (RASi) in patients with non-alcoholic fatty liver disease (NAFLD) because they may reduce oxidative stress, inflammatory markers, and enhanced fibrosis. An objective of this study was to investigate the role of RASi on NAFLD development and progression in a large cohort. We conducted a nested case-control study. Study subjects were classified into two study cohorts according to baseline NAFLD status: non-NAFLD (n = 184,581) and established NALFD (n = 27,565). An NAFLD development or progression case was defined as a patient with newly developed NAFLD or new progression of advanced fibrosis from non-NAFLD and established NALFD cohorts, respectively. A conditional logistic regression analysis was conducted to estimate the associations between RASi exposure and NAFLD development/progression. Overall, no significant association was evident between RASi use and NAFLD development or progression (NAFLD development; ever-user vs. never-user: OR 1.017; 95% CI 0.842-1.230, NAFLD progression; ever-user vs. never-user: aOR 0.942; 95% CI 0.803-1.105). RASi ever-use in cases of individuals who were obese or who had normal fasting plasma glucose (FPG) was associated with reduced risk of both NAFLD development (body mass index (BMI) ≥ 25 kg/m2: 0.708 [95% confidence interval (CI) 0.535-0.937], FPG of < 100 mg/mL: 0.774 [95% CI 0.606-0.987]) and progression (BMI ≥ 25 kg/m2: 0.668 [95% CI 0.568-0.784], FPG of < 100 mg/mL: 0.732 [95% CI 0.582-0.921]). The present study did not verify a significant overall association between RASi use and NAFLD development/progression but suggested that RASi might prevent NAFLD development and progression among specific subjects.

Older age and HDL-cholesterol as independent predictors of liver fibrosis assessed by BARD score

BACKGROUND

It is known that non-alcoholic fatty liver disease (NAFLD), and in particular non-alcoholic steatohepatitis, can progress to advanced fibrosis. However, pathophysiological mechanisms implicated in this evolution are not elucidated yet. We aimed to investigate the independent predictors of liver fibrosis in patients with NAFLD, determined by BARD score, one of the most used algorithms for fibrosis evaluation.

METHODS

This prospective study enrolled a total of 301 participants with NAFLD, as determined by a Fatty Liver Index (FLI) ≥60. All patients were categorized into two groups: with no/mild fibrosis (BARD score 1, N.=62) and with advanced fibrosis (BARD score 2, 3 and 4 N.=239).

RESULTS

Serum high density lipoprotein cholesterol (HDL-c), glucose and glycated hemoglobin were higher (P=0.028, P<0.001 and P=0.002, respectively), whereas serum transaminases and gamma glutamil transferase levels were lower in patients with advanced fibrosis than in those with no/mild fibrosis (P=0.010, P<0.001 and P=0.005, respectively). There were no significant differences in oxidative stress (i.e., advanced oxidant protein products and malondialdehyde) and anti-oxidative protection markers (i.e., catalase) between patients with no/mild fibrosis and advanced fibrosis. Multivariate ordinal regression analysis showed independent associations and predictions of ages (OR=1.071, 95% CI 1.004-1.097, P<0.001), and HDL-c levels (OR=2.549, 95% CI 1.087-5.989, P=0.032) on BARD score categories in patients with NAFLD.

CONCLUSIONS

In conclusion, we found that older age and higher HDL-c, are independent predictors for advanced liver fibrosis assessed with the BARD score. Future investigations are needed to further explore this relationship.

Noninvasive Assessment of Advanced Fibrosis Based on Hepatic Volume in Patients with Nonalcoholic Fatty Liver Disease

Background/Aims

Noninvasive liver fibrosis evaluation was performed in patients with nonalcoholic fatty liver disease (NAFLD). We used a quantitative method based on the hepatic volume acquired from gadoxetate disodium-enhanced (Gd-EOB-DTPA-enhanced) magnetic resonance imaging (MRI) for diagnosing advanced fibrosis in patients with NAFLD.

Methods

A total of 130 patients who were diagnosed with NAFLD and underwent Gd-EOB-DTPA-enhanced MRI were retrospectively included. Histological data were available for 118 patients. Hepatic volumetric parameters, including the left hepatic lobe to right hepatic lobe volume ratio (L/R ratio), were measured. The usefulness of the L/R ratio for diagnosing fibrosis ≥F3–4 and F4 was assessed using the area under the receiver operating characteristic (AUROC) curve. Multiple regression analysis was performed to identify variables (age, body mass index, serum fibrosis markers, and histological features) that were associated with the L/R ratio.

Results

The L/R ratio demonstrated good performance in differentiating advanced fibrosis (AUROC, 0.80; 95% confidence interval, 0.72 to 0.88) from cirrhosis (AUROC, 0.87; 95% confidence interval, 0.75 to 0.99). Multiple regression analysis showed that only fibrosis was significantly associated with the L/R ratio (coefficient, 0.121; p<0.0001).

Conclusions

The L/R ratio, which is not influenced by pathological parameters other than fibrosis, is useful for diagnosing cirrhosis in patients with NAFLD.

Non-invasive assessment of non-alcoholic fatty liver disease: Clinical prediction rules and blood-based biomarkers

The correct identification of patients at increased risk of non-alcoholic steatohepatitis (NASH) and advanced fibrosis is a critical step in the assessment of non-alcoholic fatty liver disease (NAFLD). Since liver biopsy is invasive, expensive and prone to sampling error, several clinical prediction rules and blood-based biomarkers have been developed as attractive and affordable alternatives for identification of patients at high risk of NASH and advanced fibrosis. Current biomarkers constitute predictive models (e.g. NAFLD fibrosis score, FIB-4 index and BARD score) or direct measures of inflammation (e.g. circulating keratin 18 fragments), or fibrosis (e.g. FibroTest®, ELF™ or Pro-C3 tests). In the clinical setting, biomarkers may discriminate between patients with NASH or advanced fibrosis, predict dynamic changes in NASH/fibrosis over time, and provide long-term prognostic information. Although clinically useful, current biomarker predictions may be influenced by hepatic and extrahepatic conditions (e.g. age, patient comorbidities, and fibrosis or NASH prevalence), which may lead to inaccurate estimates in small subsamples of patients. No highly sensitive and specific tests are available to differentiate NASH from simple steatosis. However, diagnostic accuracy can be improved by combining blood biomarkers. NAFLD fibrosis score and FIB-4 index are both cost-effective and highly sensitive tools to exclude patients with advanced fibrosis. Moreover, their higher scores may identify patients at higher risk of non-liver- and liver-related morbidity and mortality. More expensive tests such as FibroTest or ELF are more specific for detection of patients with significant and advanced fibrosis. Recent efforts have concentrated on "omics" approaches for developing and validating novel biomarkers. Herein, we describe currently available clinical prediction rules and blood-based biomarkers for identifying NASH and advanced fibrosis in patients with NAFLD, discussing their advantages and disadvantages, as well as their potential clinical utility for predicting dynamic changes over time and identifying patients at increased risk of adverse outcomes.

Systematic review and meta-analysis: non-invasive detection of non-alcoholic fatty liver disease related fibrosis in the obese

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a significant disease burden in obesity. Liver fibrosis is an important prognostic factor in NAFLD, and detection is vital. The pathophysiological changes of obesity can alter the accuracy of non-invasive NAFLD tests. We aimed to review current evidence for common non-invasive tests for NAFLD-related fibrosis in obesity.

METHODS

We systematically searched for studies assessing the diagnostic accuracy of 11 biomarker panels and elastography techniques for NAFLD-related fibrosis in obesity. Meta-analyses were performed where possible.

RESULTS

Thirty-eight studies were identified assessing the selected tests in obese populations. Simple biomarker panels (e.g. NAFLD fibrosis score) were the most validated. Evidence showed better accuracy of complex biomarker panels (NAFLD fibrosis score: summary receiver operator characteristic [SROC] 0.795-0.813 vs. enhanced liver fibrosis: SROC 0.962); however, these were poorly validated in obesity. Elastography techniques were better studied and had high diagnostic accuracy (transient elastography: SROC 0.859; magnetic resonance elastography: SROC 0.965) but were limited by BMI-dependent failure. Limited evidence was found to validate the accuracy of any test in exclusively obese populations.

CONCLUSION

In obese subjects, complex biomarker panels and elastography have been reasonable to good accuracy for NAFLD-related fibrosis; however, these methods have not been well validated. Further study in this high-risk population is needed.

Current complications and challenges in nonalcoholic steatohepatitis screening and diagnosis

Nonalcoholic steatohepatitis (NASH) can lead to complications such as liver failure, cirrhosis and hepatocellular carcinoma. The diagnostic gold standard for NASH is liver biopsy; however, other noninvasive methods have been developed. In this article, the authors evaluate current methods in NASH screening and diagnosis. Routine radiologic modalities were found to detect hepatic steatosis accurately, but were unable to establish the diagnosis of NASH or stage of fibrosis. Newly developed elastography based techniques seem promising to estimate liver fibrosis. Other noninvasive tests such as FibroTest, ELF, Hepascore, FIB-4, NFS, FLI and ION (biochemical panels) have AUROCs ranging between 0.80-0.98 for detecting advanced fibrosis but lack specificity for detecting mild fibrosis. Noninvasive tools, especially elastography, identify NASH associated advanced fibrosis potentially reducing liver biopsies. More research is needed to validate the clinical utility of these tests.

Clinical Implications of the Serum Apelin Level on Portal Hypertension and Prognosis of Liver Cirrhosis

BACKGROUND/AIMS

Levels of serum apelin (s-apelin), an endogenous ligand for angiotensin-like receptor 1, have been shown to be related to hepatic fibrosis and hemodynamic abnormalities in preclinical studies. We investigated the clinical implications of s-apelin as a noninvasive prognostic biomarker for chronic liver disease (CLD).

METHODS

From January 2009 to December 2012, 215 CLD patients were enrolled and underwent clinical data collection, hepatic venous pressure gradient (HVPG) measurement, and liver biopsy. s-apelin was detected with a human total apelin enzyme-linked immunosorbent assay kit. All patients were prospectively observed during the median follow-up period of 23.0±12.9 months for decompensation and mortality.

RESULTS

A total of 42 patients (19.5%) died during the follow-up period. s-apelin was significantly correlated with measurements of liver stiffness (R2=0.263, p<0.001) and collagen proportional area (R2=0.213, p<0.001) measured from liver biopsy tissue and HVPG (R2=0.356, p<0.001). In a multivariate analysis using a Cox regression hazard model, s-apelin was a weakly significant predictor of decompensation (hazard ratio [HR], 1.002; p<0.001) and mortality (HR, 1.003; p<0.001).

CONCLUSIONS

s-apelin showed a significant relationship with CLD severity. However, its significance as a noninvasive biomarker for disease severity and prognosis was weak.

Fibrosis Assessment in Nonalcoholic Fatty Liver Disease (NAFLD) in 2016

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver pathologies characterized by hepatic steatosis with a history of little to no alcohol consumption or secondary causes of hepatic steatosis. The prevalence of NAFLD is 20-25 % of the general population in the Western countries and is associated with metabolic risk factors such as obesity, diabetes mellitus, and dyslipidemia. The spectrum of disease ranges from simple steatosis to nonalcoholic steatohepatitis, fibrosis, and cirrhosis. Advanced fibrosis is the most significant predictor of mortality in NAFLD. It is crucial to assess for the presence and degree of hepatic fibrosis in order to make therapeutic decisions and predict clinical outcomes. Liver biopsy, the current gold standard to assess the liver fibrosis, has a number of drawbacks such as invasiveness, sampling error, cost, and inter-/intra-observer variability. There are currently available a number of noninvasive tests as an alternative to liver biopsy for fibrosis staging. These noninvasive fibrosis tests are increasingly used to rule out advanced fibrosis and help guide disease management. While these noninvasive tests perform relatively well for ruling out advanced fibrosis, they also have limitations. Understanding the strengths and limitations of liver biopsy and the noninvasive tests is necessary for deciding when to use the appropriate tests in the evaluation of patients with NAFLD.

Diagnostic usefulness of FibroMeter VCTE for hepatic fibrosis in patients with nonalcoholic fatty liver disease

BACKGROUND

Liver fibrosis is an important prognostic determinant in patients with nonalcoholic fatty liver disease (NAFLD). The FibroMeter VCTE is a diagnostic tool comprising both biochemical markers and transient elastography (TE) originally developed for the diagnosis of fibrosis in patients with chronic viral hepatitis. In this pilot study, we investigated the diagnostic performance of the FibroMeter VCTE tool for determining fibrosis in patients with biopsy-proven NAFLD. Its diagnostic accuracy was also compared with those of the NAFLD fibrosis score (NFSA) and TE alone.

PATIENTS AND METHODS

FibroMeter VCTE, NFSA, and TE were determined in 52 patients with NAFLD. The results of liver biopsies were considered the gold standard. Areas under the receiver operating characteristic curve were used to express the diagnostic accuracy of each test.

RESULTS

Significant (F≥2) and severe (F≥3) fibrosis were detected in 20 (38%) and 10 (19%) patients, respectively. The sensitivity of FibroMeter VCTE, NFSA, and TE for detecting significant fibrosis was 70, 65, and 75%, respectively, whereas specificity was 88, 81, and 78%. The sensitivity of FibroMeter VCTE, NFSA, and TE for diagnosing severe fibrosis was 90, 90, and 100%, respectively, whereas specificity was 93, 78, and 76%. Receiver operating characteristic analysis showed that FibroMeter VCTE had a significantly larger areas under the receiver operating characteristic curve (0.968) compared with both NFSA (0.833, P<0.001) and TE (0.922, P<0.05) for the detection of severe fibrosis.

CONCLUSION

Our preliminary findings indicate that FibroMeter VCTE is superior to both NFSA and TE for the diagnosis of severe fibrosis in patients with NAFLD.

Composite prognostic models across the non-alcoholic fatty liver disease spectrum: Clinical application in developing countries

Heterogeneity in clinical presentation, histological severity, prognosis and therapeutic outcomes characteristic of non-alcoholic fatty liver disease (NAFLD) necessitates the development of scientifically sound classification schemes to assist clinicians in stratifying patients into meaningful prognostic subgroups. The need for replacement of invasive liver biopsies as the standard method whereby NAFLD is diagnosed, graded and staged with biomarkers of histological severity injury led to the development of composite prognostic models as potentially viable surrogate alternatives. In the present article, we review existing scoring systems used to (1) confirm the presence of undiagnosed hepatosteatosis; (2) distinguish between simple steatosis and NASH; and (3) predict advanced hepatic fibrosis, with particular emphasis on the role of NAFLD as an independent cardio-metabolic risk factor. In addition, the incorporation of functional genomic markers and application of emerging imaging technologies are discussed as a means to improve the diagnostic accuracy and predictive performance of promising composite models found to be most appropriate for widespread clinical adoption.

Non-invasive Testing for NASH and NASH with Advanced Fibrosis: Are We There Yet?

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent etiology of chronic liver disease in America. NAFLD can be broadly classified in two subtypes: nonalcoholic fatty liver (NAFL), which is generally considered a benign condition with negligible risk of progression to cirrhosis, and nonalcoholic steatohepatitis (NASH), which is generally considered to be progressive with substantial risk of progression to cirrhosis. Additionally, recent studies suggest the odds of liver mortality increases amongst NASH patients with advanced fibrosis (bridging fibrosis ± cirrhosis). Liver biopsy examination is the current gold standard to accurately discriminate between NAFL vs. NASH as well as diagnose advanced fibrosis. However, due to its invasive nature, risk of bleeding (and even rarely death), prohibitive cost, and sampling error, liver biopsies are imperfect for diagnosis and monitoring of NAFLD. As a result, noninvasive biomarkers that can accurately detect NASH and advanced fibrosis without biopsy are needed. This article will discuss the most novel noninvasive biomarkers in diagnosing NASH and advanced fibrosis.

Comparison of noninvasive scores for the detection of advanced fibrosis in patients with nonalcoholic fatty liver disease

BACKGROUND

The presence of advanced liver fibrosis portends a poor prognosis in nonalcoholic fatty liver disease (NAFLD). We aimed to compare the diagnostic performance of five noninvasive scores [aspartate aminotransferase/platelet ratio (APRI), BARD, FIB-4, NAFLD fibrosis score (NFSA), and FibroMeter] for the assessment of advanced stages of fibrosis (F ≥ 3) in patients with biopsy-proven NAFLD.

METHODS

APRI, BARD, FIB-4, NFSA, and FibroMeter scores were determined in 142 patients with NAFLD. The histopathological analysis of liver biopsies was considered the gold standard. Sensitivity and specificity were calculated for each noninvasive test using receiver operating characteristic (ROC) curve analysis, with a cut-off value of F ≥ 3 for advanced fibrosis. The diagnostic accuracies were assessed by measuring the area under the ROC curve (AUROC). The AUROCs for different noninvasive tests were compared using paired significance tests.

RESULTS

At histopathological examination, 40 patients (28.2%) had a fibrosis stage F0, 50 patients (35.2%) had F1, 22 patients (15.5%) had F2, 20 patients (14.1%) had F3, and 10 patients (7.0%) had F4. The sensitivity of APRI, BARD, FIB-4, NFSA, and FibroMeter scores for advanced fibrosis was 70.0, 73.3, 70.0, 66.7, and 66.7%, respectively, and the specificity was 74.5, 66.4, 71.8, 71.8, and 74.5%, respectively. No significant differences in terms of sensitivity and specificity were evident for the five noninvasive scores. Moreover, the AUROCs did not differ significantly for all scores.

CONCLUSION

Our study suggests that different noninvasive scores have similar accuracy for the diagnosis of advanced hepatic fibrosis in NAFLD.

Noninvasive Assessment of Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is prevalent in 20-25% of the general population and is associated with metabolic risk factors such as obesity, diabetes mellitus, and dyslipidemia. Histologically, NAFLD ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. As NASH develops in only 10-15% of patients with NAFLD, it is not practical to biopsy all patients who present with NAFLD. Noninvasive fibrosis tests have been extensively developed recently and offer alternatives for staging fibrosis. Despite their increasing use, such tests cannot adequately differentiate simple steatosis from NASH. At present, such tests can be used as first line tests to rule out patients without advanced fibrosis and thus prevent unnecessary secondary care referrals in a significant number of patients. In this review we present the evidence for the use of noninvasive fibrosis tests in patients with NAFLD.