Diagnostic accuracy of FibroScan-AST score to identify non-alcoholic steatohepatitis with significant activity and fibrosis in Japanese patients with non-alcoholic fatty liver disease: Comparison between M and XL probes

A Real-World Experience Utilizing the FAST Score to Identify Patients With Nonalcoholic Steatohepatitis Fibrosis

Background and Aims

We aimed to test the performance of the Fibroscan-aspartate aminotransferase (FAST) score, a noninvasive test, to identify nonalcoholic steatohepatitis (NASH) and significant fibrosis (NASH + ≥F2) in a cohort of patients with a histological diagnosis of NASH, using a cutoff of ≥0.35 as a rule in factor. We also compared performance to liver stiffness measurement (LSM) ≥8 kPa and the fibrosis-4 index (FIB-4) ≥1.3 and attempted to identify risk factors to develop a model for improving diagnostic accuracy.

Methods

Patients with histologically confirmed NASH were identified from 2020-2021. Demographic information, laboratory data, and LSM were collected. The FAST score and FIB-4 were calculated. Univariate and backward entry multivariate logistic regression analyses were performed to identify risk factors in addition to the FAST score ≥0.35 that are associated with an accurate histological diagnosis of NASH + ≥F2. Discrimination and overall accuracy were assessed using area under receiver operating characteristic curves.

Results

Using a rule in cutoff of ≥0.35, the FAST score performed with a sensitivity, specificity, negative predictive value, and positive predictive value of 96.4%, 36.8%, 77.7%, and 81.8%, respectively. Age (P = .05) and FAST ≥0.35 (P = .001) correctly identified histologically confirmed NASH + ≥F2. The FAST + age model outperformed FAST ≥0.35 (0.70, confidence interval [CI]: 0.55-0.84), LSM ≥8 kPa (0.72, CI: 0.59-0.85), and FIB-4 ≥1.3 (0.73, CI: 0.59-0.87) with a c-statistic of 0.78 (CI: 0.64-0.92).

Conclusion

A FAST score with a rule cutoff of ≥0.35 performed well (c-statistic: 0.70) and was superior to LSM and FIB-4 when age was incorporated into the model (0.78) in detecting NASH + ≥F2 fibrosis in the real world.

Gamma-glutamyl transferase predicts pemafibrate treatment response in non-alcoholic fatty liver disease

BACKGROUND AND AIM

Pemafibrate, a selective peroxisome proliferator activated receptor α modulator, has been shown to improve liver function among nonalcoholic fatty liver disease (NAFLD) patients with dyslipidemia. The aim of this retrospective study is to identify predictors of pemafibrate efficacy in NAFLD patients.

METHODS

A total of 75 NAFLD patients with dyslipidemia who received pemafibrate twice per day for 48 weeks were enrolled in this study. We used the FibroScan-aspartate aminotransferase (FAST) score as a benchmark for treatment efficacy.

RESULTS

Median FAST score significantly decreased from 0.96 at baseline to 0.93 at week 48 (P < 0.001). Significant improvements in levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and triglycerides were also noted. The serum level of GGT at baseline was correlated with change in FAST score (r = -0.22, P = 0.049). Changes in AST, ALT, and GGT were positively correlated with change in FAST score (r = 0.71, r = 0.61, and r = 0.38). Multivariate analyses identified age and GGT level at baseline as significantly associated with improvement of FAST score by pemafibrate therapy (odds ratio 1.11, 1.02, respectively). Patients over 50 years of age and with a GGT of 90 IU/L or higher showed significantly greater improvement in the FAST score than other groups.

CONCLUSIONS

Pemafibrate improves the FAST score of NAFLD patients with complicating dyslipidemia, especially in older patients with high GGT level. GGT is useful as an indicator of optimal treatment choice for NAFLD patients with dyslipidemia.

M-PAST score is better than MAST score for the diagnosis of active fibrotic nonalcoholic steatohepatitis

BACKGROUND

Clinical trials enroll patients with active fibrotic nonalcoholic steatohepatitis (NASH) (nonalcoholic fatty liver disease [NAFLD] activity score ≥ 4) and significant fibrosis (F ≥ 2); however, screening failure rates are high following biopsy. We developed new scores to identify active fibrotic NASH using FibroScan and magnetic resonance imaging (MRI).

METHODS

We undertook prospective primary (n = 176), retrospective validation (n = 169), and University of California San Diego (UCSD; n = 234) studies of liver biopsy-proven NAFLD. Liver stiffness measurement (LSM) using FibroScan or magnetic resonance elastography (MRE), controlled attenuation parameter (CAP), or proton density fat fraction (PDFF), and aspartate aminotransferase (AST) were combined to develop a two-step strategy-FibroScan-based LSM followed by CAP with AST (F-CAST) and MRE-based LSM followed by PDFF with AST (M-PAST)-and compared with FibroScan-AST (FAST) and MRI-AST (MAST) for diagnosing active fibrotic NASH. Each model was categorized using rule-in and rule-out criteria.

RESULTS

Areas under receiver operating characteristic curves (AUROCs) of F-CAST (0.826) and M-PAST (0.832) were significantly higher than those of FAST (0.744, p = 0.004) and MAST (0.710, p < 0.001). Following the rule-in criteria, positive predictive values of F-CAST (81.8%) and M-PAST (81.8%) were higher than those of FAST (73.5%) and MAST (70.0%). Following the rule-out criteria, negative predictive values of F-CAST (90.5%) and M-PAST (90.9%) were higher than those of FAST (84.0%) and MAST (73.9%). In the validation and UCSD cohorts, AUROCs did not differ significantly between F-CAST and FAST, but M-PAST had a higher diagnostic performance than MAST.

CONCLUSIONS

The two-step strategy, especially M-PAST, showed reliability of rule-in/-out for active fibrotic NASH, with better predictive performance compared with MAST. This study is registered with ClinicalTrials.gov (number, UMIN000012757).

Roles of Radiological Tests in Clinical Trials and the Clinical Management of Nonalcoholic Fatty Liver Disease

Radiological testing is now routinely used for clinical trial prescreening, diagnosis, and treatment and referral. The CAP performs well in detecting fatty liver but is unable to grade and track longitudinal changes. MRI-PDFF is a better technique for evaluating longitudinal changes and is used as a primary endpoint in trials of antisteatotic agents. The probability of detecting liver fibrosis using radiological testing techniques is high when performed at referral centers, and reasonable imaging strategies include the combination of FIB-4 and VCTE, the FAST Score, MAST, and MEFIB. The strategy currently recommended is the sequential application of FIB-4 and VCTE.

Diagnostic accuracy of FibroScan-AST (FAST) score for the non-invasive identification of patients with fibrotic non-alcoholic steatohepatitis: a systematic review and meta-analysis

OBJECTIVE

A simple combined score with liver stiffness, controlled attenuation parameter and serum aspartate aminotransferase (AST), the FibroScan-AST (FAST) score, has been proposed to non-invasively identify patients with fibrotic non-alcoholic steatohepatitis (NASH). We performed a systematic review and meta-analysis of published studies to evaluate the overall diagnostic accuracy of the FAST score in identifying patients with fibrotic NASH.

DESIGN

We systematically searched MEDLINE, Ovid Embase, Scopus and Cochrane Library electronic databases for full-text published articles in any language between 3 February 2020 and 30 April 2022. We included original articles that reported data for the calculation of sensitivity and specificity of the FAST score for identifying adult patients with fibrotic NASH adults, according to previously described rule-out (≤0.35) and rule-in (≥0.67) cut-offs.

RESULTS

We included 12 observational studies for a total of 5835 participants with biopsy-confirmed non-alcoholic fatty liver disease. The pooled prevalence of fibrotic NASH was 28% (95% CI 21% to 34%). The FAST score's pooled sensitivity was 89% (95% CI 82% to 93%), and the pooled specificity was 89% (95% CI 83% to 94%) according to the aforementioned rule-in/rule-out cut-offs. The negative predictive value and positive predictive value of the FAST score were 92% (95% CI 91% to 95%) and 65% (95% CI 53% to 68%), respectively. Subgroup analyses and influential bias analyses did not alter these findings.

CONCLUSION

The results of our meta-analysis show that the FAST score has a good performance for non-invasive diagnosis of fibrotic NASH. Therefore, this score can be used to efficiently identify patients who should be referred for a conclusive liver biopsy and/or consideration for treatment with emerging pharmacotherapies.

PROSPERO REGISTRATION NUMBER

CRD42022350945.

Prevalence of at-risk NASH and its association with metabolic syndrome in US adults with NAFLD, 2017-2018

Patients with metabolic syndrome (MetS) have a higher risk for NASH and significant fibrosis. Presence of NASH and advanced fibrosis are associated with adverse outcomes in patients with NAFLD. Using a noninvasive method, we determined the prevalence of at-risk NASH and its association with MetS components in a large population-based analysis. We used the 2017-2018 National Health and Nutrition Examination Survey and included adults ≥18 years with NAFLD (controlled attenuation parameter ≥274 dB/m). Pregnancy, subjects with other causes of liver disease or missing data were excluded. FibroScan-AST (FAST) score was calculated using aspartate aminotransferase, liver stiffness measurement, and controlled attenuation parameter. Patients with a FAST score >0.35 were considered to have at-risk NASH, defined as NASH with NAFLD activity score ≥4 and fibrosis stage ≥2 on liver biopsy. The sample included 687 patients. The overall prevalence of at-risk NASH was 11.6% (95% CI: 8.8-15.1) and was higher in males than females (15.8% vs. 6.5%; p < 0.001). Subjects with comorbidities (diabetes mellitus, obesity, MetS, and insulin resistance) had between 1.3 and 1.7 times higher prevalence than the general population. Among MetS components, elevated glucose/diabetes, large waist circumference, and low HDL were independent risk factors for at risk-NASH. The number of MetS components was also important-one additional component increased the odds of at-risk NASH by 2 times. The FAST score had the highest correlation with alanine aminotransferase (r= 0.70; p < 0.001). We estimated ~9 million people in the US have at-risk NASH and may benefit from active surveillance and therapy.

SWOT analysis of noninvasive tests for diagnosing NAFLD with severe fibrosis: an expert review by the JANIT Forum

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Recently, the prognosis of NAFLD/NASH has been reported to be dependent on liver fibrosis degree. Liver biopsy remains the gold standard, but it has several issues that must be addressed, including its invasiveness, cost, and inter-observer diagnosis variability. To solve these issues, a variety of noninvasive tests (NITs) have been in development for the assessment of NAFLD progression, including blood biomarkers and imaging methods, although the use of NITs varies around the world. The aim of the Japan NASH NIT (JANIT) Forum organized in 2020 is to advance the development of various NITs to assess disease severity and/or response to treatment in NAFLD patients from a scientific perspective through multi-stakeholder dialogue with open innovation, including clinicians with expertise in NAFLD/NASH, companies that develop medical devices and biomarkers, and professionals in the pharmaceutical industry. In addition to conventional NITs, artificial intelligence will soon be deployed in many areas of the NAFLD landscape. To discuss the characteristics of each NIT, we conducted a SWOT (strengths, weaknesses, opportunities, and threats) analysis in this study with the 36 JANIT Forum members (16 physicians and 20 company representatives). Based on this SWOT analysis, the JANIT Forum identified currently available NITs able to accurately select NAFLD patients at high risk of NASH for HCC surveillance/therapeutic intervention and evaluate the effectiveness of therapeutic interventions.

Validation and Performance of FibroScan®-AST (FAST) Score on a Brazilian Population with Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIM

FAST score has a good performance for diagnosing the composite of NASH + NAS ≥ 4 + F ≥ 2. However, it has not been evaluated in Latin American individuals with nonalcoholic fatty liver disease (NAFLD). We aimed to analyze the performance of the FAST score in a Brazilian NAFLD population.

METHODS

Cross-sectional study was held in ≥ 18 years NAFLD patients diagnosed by ultrasonography and submitted to liver biopsy (LB). Liver stiffness (LSM) and CAP measurements were performed with FibroScan®, using M (BMI < 32 kg/m²) or XL probes. Area under receiver operating characteristic (AUROC) curves were calculated as well as sensitivity (S), specificity (Spe), positive predictive value (VPP) and negative predictive value (NPV) for the previously established FAST score cut-offs.

RESULTS

Among 287 patients included (75% female; mean age 55 ± 10 years), NASH + NAS ≥ 4 + F ≥ 2 was reported in 30% of LB. For the FAST cut-off of 0.35, the S and NPV to rule out NASH + NAS ≥ 4 + F ≥ 2 were 78.8% and 87.8%, respectively. Regarding the cut-off of 0.67, the Spe and PPV to rule-in NASH + NAS ≥ 4 + F ≥ 2 were 89.1%, 61.8%, respectively. The AUROC of FAST for all included patients was 0.78 (95% CI 0.72-0.84) and for those with ≥ 32 kg/m² was 0.81 (95% CI 0.74-0.88).

CONCLUSION

FAST score has a good performance in a Brazilian NAFLD population, even in patients with higher BMI when the XL probe is adopted. Therefore, FAST can be used as a noninvasive screening tool mainly for excluding the diagnosis of progressive NASH, reducing the number of unnecessary liver biopsies.

Noninvasive assessment of liver fibrosis and its clinical significance in nonalcoholic fatty liver disease

Liver fibrosis is the most important prognostic factor in patients with nonalcoholic fatty liver disease (NAFLD). Several noninvasive markers for fibrosis, including blood-based markers and imaging based-markers have been developed. Indirect fibrosis markers (e.g., fibrosis-4 index and NAFLD fibrosis score) consist of standard laboratory data and clinical parameters. Given its availability and high negative predictive value for advanced fibrosis, these markers are suitable for screening at primary care. Blood-based fibrogenesis markers (enhanced liver fibrosis and N-terminal propeptide of type 3 collagen), ultrasound-based modalities (vibration-controlled transient elastography, point shear wave elastography [SWE], and two-dimensional SWE), and magnetic resonance elastography have high diagnostic accuracy for liver fibrosis and are suitable for diagnosing liver fibrosis at secondary care centers. Sequential use of these markers can increase diagnostic accuracy and reduce health care costs. Furthermore, combining noninvasive makers may assist in identifying candidates for pharmacological trials and reducing screening failure. Emerging data suggest that these noninvasive markers are associated with liver-related events (hepatocellular carcinoma and decompensation) and mortality. Furthermore, delta change in noninvasive markers over time is also associated with time-course change in fibrosis, liver-related event risk, and mortality risk. However, the association between liver fibrosis and cardiovascular disease (CVD) risk is still controversial. CVD risk may decrease in patients with decompensated liver disease and noninvasive markers may be useful for assessing CVD risk in these patients. Therefore, noninvasive markers may be utilized as measures of fibrosis as well as real-time prognostic tools, in place of liver biopsy.

Distribution of FIB-4 index in the general population: analysis of 75,666 residents who underwent health checkups

Background

Fatty liver is frequently found in a general population, and it is critical to detect advanced fibrosis. FIB-4 index is considered a useful marker for evaluating liver fibrosis but the distribution of FIB-4 index in the general population remains unknown.

Methods

This cross-sectional study included residents who underwent ultrasonography at health checkups in Hiroshima or Iwate prefectures. The distribution of FIB-4 index in the total study population (N = 75,666) as well as in non-alcoholic fatty liver disease (NAFLD) populations (N = 17,968) and non-drinkers without fatty liver populations (N = 47,222) was evaluated. The distribution of aspartate aminotransferase (AST) levels, alanine aminotransferase (ALT) levels was also evaluated.

Results

The mean FIB-4 index in the total study population was 1.20 ± 0.63. FIB-4 index ≥ 2.67, which indicates a high risk of liver fibrosis, was found in 16.4% of those aged ≥ 70 years. In the NAFLD population, 58.1% of those in their 60 s and 88.1% of those ≥ 70 years met the criteria for referral to hepatologists by using the recommended FIB-4 index cutoff value (≥ 1.3). The mean FIB-4 index in the NAFLD population (1.12 ± 0.58) was significantly lower than in the non-drinkers without fatty liver (1.23 ± 0.63, p < 0.0001). The non-drinkers without fatty liver tended to have higher AST relative to ALT levels (60.0% with AST/ALT > 1.0), whereas the results in the NAFLD population were opposite (14.8% with AST/ALT > 1.0). AST > ALT resulted in a higher FIB-4 index in non-drinkers without fatty liver due to the nature of FIB-4 index formula.

Conclusions

The cutoff value of FIB-4 index (≥ 1.3) for triaging the elderly people with fatty liver for referral to hepatologists should be reconsidered to avoid over-referral. Due to the impact of age and characteristics of AST/ALT ratios, there is no prospect of using FIB-4 index for primary screening for liver fibrosis in a general population of unknown presence or absence of liver disease, even though it can be easily calculated using routine clinical indices. It is desired to develop a non-invasive method for picking up cases with advanced fibrosis latent in the general population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02290-1.

Validation of the accuracy of the FAST™ score for detecting patients with at-risk nonalcoholic steatohepatitis (NASH) in a North American cohort and comparison to other non-invasive algorithms

BACKGROUND AND AIMS

Management of patients with NASH who are at elevated risk of progressing to complications of cirrhosis (at-risk NASH) would be enhanced by an accurate, noninvasive diagnostic test. The new FAST™ score, a combination of FibroScan® parameters liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) and aspartate aminotransferase (AST), has shown good diagnostic accuracy for at-risk NASH (area-under-the-Receiver-Operating-Characteristic [AUROC] = 0.80) in European cohorts. We aimed to validate the FAST™ score in a North American cohort and show how its diagnostic accuracy might vary by patient mix. We also compared the diagnostic performance of FAST™ to other non-invasive algorithms for the diagnosis of at-risk NASH.

METHODS

We studied adults with biopsy-proven non-alcoholic fatty liver disease (NAFLD) from the multicenter NASH Clinical Research Network (CRN) Adult Database 2 (DB2) cohort study. At-risk-NASH was histologically defined as definite NASH with a NAFLD Activity Score (NAS) ≥ 4 with at least 1 point in each category and a fibrosis stage ≥ 2. We used the Echosens® formula for FAST™ from LSM (kPa), CAP (dB/m), and AST (U/L), and the FAST™-based Rule-Out (FAST™ ≤ 0.35, sensitivity = 90%) and Rule-In (FAST™ ≥ 0.67, specificity = 90%) zones. We determined the following diagnostic performance measures: AUROC, sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV); these were calculated for the total sample and by subgroups of patients and by FibroScan® exam features. We also compared the at-risk NASH diagnostic performance of FAST™ to other non-invasive algorithms: NAFLD fibrosis score (NFS), Fibrosis-4 (FIB-4) index, and AST to platelet ratio index (APRI).

RESULTS

The NASH CRN population of 585 patients was 62% female, 79% white, 14% Hispanic, and 73% obese; the mean age was 51 years. The mean (SD) AST and ALT were 50 (37) U/L and 66 (45) U/L, respectively. 214 (37%) had at-risk NASH. The AUROC of FAST™ for at-risk NASH in the NASH CRN study population was 0.81 (95% CI: 0.77, 0.84. Using FAST™-based cut-offs, 35% of patients were ruled-out with corresponding NPV = 0.90 and 27% of patients were ruled-in with corresponding PPV = 0.69. The diagnostic accuracy of FAST™ was higher in non-whites vs. whites (AUROC: 0.91 vs 0.78; p = 0.001), and in patients with a normal BMI vs. BMI > 35 kg/m2 (AUROC: 0.94 vs 0.78, p = 0.008). No differences were observed by other patient characteristics or FibroScan® exam features. The FAST™ score had higher diagnostic accuracy than other non-invasive algorithms for the diagnosis of at-risk NASH (AUROC for NFS, FIB-4, and APRI 0.67, 0.73, 0.74, respectively).

CONCLUSION

We validated the FAST™ score for the diagnosis of at-risk NASH in a large, multi-racial population in North America, with a prevalence of at-risk NASH of 37%. Diagnostic performance varies by subgroups of NASH patients defined by race and obesity. FAST™ performed better than other non-invasive algorithms for the diagnosis of at-risk NASH.

Comparison of FibroScan-Aspartate Aminotransferase (FAST) Score and Other Non-invasive Surrogates in Predicting High-Risk Non-alcoholic Steatohepatitis Criteria

Identification of non-alcoholic steatohepatitis (NASH) with high activity and fibrosis is a major priority in patients with non-alcoholic fatty liver disease. We validated the predictive value of the FibroScan-aspartate aminotransferase (FAST) score and other non-invasive fibrosis surrogates in predicting high-risk NASH criteria. This multicenter retrospective study recruited 251 biopsy-proven non-alcoholic fatty liver disease (NAFLD) patients (132 [52.6%] men) between 2011 and 2014. The FAST score was calculated using transient elastography data and aspartate aminotransferase (AST) levels. The NAFLD fibrosis score (NFS), fibrosis-4 index (FIB-4), and AST to platelet ratio index (APRI) were calculated using biochemical data. The area under the receiver operating characteristic curves (AUCs) of the FAST score, liver stiffness, NFS, FIB-4, and APRI were 0.752, 0.718, 0.609, 0.650, and 0.722 for NAFLD activity score (NAS) ≥5 (n = 117, 46.6%); 0.788, 0.754, 0.649, 0.701, and 0.747 for fatty liver inhibition of progression-NASH with histologic activity ≥3 (n = 202, 80.5%); 0.807, 0.806, 0.691, 0.732, and 0.760 for severe disease with activity ≥3 and/or fibrosis ≥3 (n = 132, 52.6%); and 0.714, 0.812, 0.748, 0.738, and 0.669 for NASH with NAS ≥4 and fibrosis ≥2 (n = 70, 27.9%), respectively. The FAST score had the highest AUC for the most high-risk NASH criteria, except for in predicting NAS ≥4 and fibrosis ≥2. The liver stiffness value showed consistently acceptable performance in predicting all high-risk NASH criteria. The FAST score has acceptable performance in identifying high-risk NASH. However, liver stiffness alone was not inferior to the FAST score.

Effect of combined farnesoid X receptor agonist and angiotensin II type 1 receptor blocker on ongoing hepatic fibrosis

OBJECTIVE

Nonalcoholic steatohepatitis (NASH) is difficult to diagnose in patients with no symptoms. We aimed to investigate the combined effect of farnesoid X receptor (FXR) agonist, obeticholic acid (OCA), and angiotensin II type 1 receptor blocker (ARB: losartan) on an ongoing hepatic fibrosis in a NASH rat model.

METHODS

Fischer 344 rats were fed with choline-deficient L-amino-acid-defined (CDAA) diet for 16 weeks. After 8-week administration of CDAA diet, OCA, losartan, or a combination of these drugs was administered at a dose of 30 mg/kg/day for 8 weeks by oral gavage. The in vivo and in vitro effects of OCA + losartan and liver fibrosis progression, lipopolysaccharide (LPS), Toll-like receptor 4 (TLR4) regulatory cascade, and gut barrier function were evaluated.

RESULTS

OCA + losartan alleviated hepatic fibrosis progression by suppressing α-SMA expression. It inhibited the proliferation of activated hepatic stellate cell (Ac-HSC) and mRNA expression of hepatic transforming growth factor-β1 (TGF-β1), TLR4, and tissue inhibitor of metalloproteinase-1 (TIMP-1) and decreased the hydroxyproline levels. OCA increased the hepatic matrix metalloproteinase-2 (MMP-2) mRNA expression. OCA decreased the mRNA expression of hepatic LPS-binding protein and intestinal permeability by ameliorating the disruption of CDAA diet-induced zonula occludens-1. Losartan directly inhibited the proliferation of Ac-HSC. The in vitro suppressive effects of OCA + losartan on the mRNA expressions of TGF-β1 and α1(I)-procollagen, TLR4, and TIMP-1 in Ac-HSCs were almost in parallel.

CONCLUSIONS

OCA + losartan suppressed the ongoing hepatic fibrosis by attenuating gut barrier dysfunction and suppressing Ac-HSC proliferation. Combined therapy may be a promising novel approach for NASH with fibrosis.

Magnetic resonance elastography plus Fibrosis-4 versus FibroScan-aspartate aminotransferase in detection of candidates for pharmacological treatment of NASH-related fibrosis

BACKGROUND AND AIMS

Patients with NAFLD with significant hepatic fibrosis (Stage ≥ 2) are at increased risk of liver-related morbidity and are candidates for pharmacologic therapies. In this study, we compared the diagnostic accuracy of MEFIB (the combination of magnetic resonance elastography [MRE] and Fibrosis-4 [FIB-4]) and FAST (FibroScan-aspartate aminotransferase; combined liver stiffness measurement by vibration-controlled transient elastography, controlled attenuation parameter, and aspartate aminotransferase) for detecting significant fibrosis.

APPROACH AND RESULTS

This prospective cohort study included 234 consecutive patients with NAFLD who underwent liver biopsy, MRE, and FibroScan at the University of California San Diego (UCSD cohort) and an independent cohort (N = 314) from Yokohama City University, Japan. The primary outcome was diagnostic accuracy for significant fibrosis (Stage ≥ 2). The proportions of significant fibrosis in the UCSD and Yokohama cohorts were 29.5% and 66.2%, respectively. Area under the receiver operating characteristic curve (95% CI) of MEFIB (0.860 [0.81-0.91]) was significantly higher than that of FAST (0.757 [0.69-0.82]) in the UCSD cohort (p = 0.005), with consistent results in the Yokohama cohort (AUROC, 0.899 [MEFIB] versus 0.724 [FAST]; p < 0.001). When used as the rule-in criteria (MEFIB, MRE ≥ 3.3 kPa and FIB-4 ≥ 1.6; FAST ≥ 0.67), the positive predictive value for significant fibrosis was 91.2%-96.0% for MEFIB and 74.2%-89.2% for FAST. When used as the rule-out criteria (MEFIB, MRE < 3.3 kPa and FIB-4 < 1.6; FAST ≤ 0.35), the negative predictive value for significant fibrosis was 85.6%-92.8% for MEFIB and 57.8%-88.3% for FAST.

CONCLUSIONS

MEFIB has higher diagnostic accuracy than FAST for significant fibrosis in NAFLD, and our results support the utility of a two-step strategy for detecting significant fibrosis in NAFLD.

Non-alcoholic Fatty Liver Disease and Depression: Evidence for Genotype × Environment Interaction in Mexican Americans

This study examines the impact of G × E interaction effects on non-alcoholic fatty liver disease (NAFLD) among Mexican Americans in the Rio Grande Valley (RGV) of South Texas. We examined potential G × E interaction using variance components models and likelihood-based statistical inference in the phenotypic expression of NAFLD, including hepatic steatosis and hepatic fibrosis (identified using vibration controlled transient elastography and controlled attenuation parameter measured by the FibroScan Device). We screened for depression using the Beck Depression Inventory-II (BDI-II). We identified significant G × E interactions for hepatic fibrosis × BDI-II. These findings provide evidence that genetic factors interact with depression to influence the expression of hepatic fibrosis.

Effect of 48-week pemafibrate on non-alcoholic fatty liver disease with hypertriglyceridemia, as evaluated by the FibroScan-aspartate aminotransferase score

Background and Aim

This retrospective study investigated the effect of 48‐week pemafibrate therapy in non‐alcoholic fatty liver disease (NAFLD) with hypertriglyceridemia, as evaluated by the FibroScan‐aspartate aminotransferase (FAST) score.

Methods

A total of 31 NAFLD patients who were treated with pemafibrate in Gunma Saiseikai Maebashi Hospital and Kusunoki Hospital from September 2018 to April 2020 were included in the current study. We used the FAST score, which is a novel index of steatohepatitis that can be calculated based on the AST value, controlled attenuation parameter (CAP), and liver stiffness measurement (LSM), to evaluate the effect of pemafibrate treatment.

Results

The median age was 64.0 (interquartile range [IQR] 55.0–75.0) years and 14 patients (45.2%) were male. Median body mass index was 26.8 (IQR 23.8–28.8). Hypertension and diabetes mellitus were detected in 14 (45.2%) and five (16.1%) patients, respectively. Fasting triglyceride and high‐density lipoprotein cholesterol were significantly improved (P < 0.001 and 0.013, respectively) and the AST, alanine aminotransferase (ALT), alkaline phosphatase, and γ‐glutamyl transpeptidase values were significantly decreased during pemafibrate treatment (P = 0.041, <0.001, <0.001, and <0.001, respectively). While the LSM value and CAP value did not differ to a statistically significant extent (P = 0.19 and 0.140, respectively), the FAST score was significantly improved during pemafibrate treatment (P = 0.029). The delta FAST score was found to be correlated with the variations of ALT (r = 0.504, P = 0.005), which represents the effect of pemafibrate.

Conclusions

Pemafibrate improved the FAST score due to the hepatic anti‐inflammatory effect, indicating that pemafibrate may prevent disease progression in NAFLD patients with hypertriglyceridemia.

Relationships of Dietary Habits and Physical Activity Status with Non-Alcoholic Fatty Liver Disease Featuring Advanced Fibrosis

(1) Aim: Hepatic fibrosis is a prognostic factor for disease progression in non-alcoholic fatty liver disease (NAFLD). We aimed to determine the relationships between diet, physical activity, and the progression of liver fibrosis. (2) Methods: The 349 participants were categorized by their FibroScan-aspartate aminotransferase score, and they completed a questionnaire regarding their diet and physical activity. (3) Results: There were 233 patients in the negative-on-screening group, 78 in the gray zone group, and 38 in the positive-on-screening group. The frequencies of consumption of soybeans and soybean products and of light-colored vegetables were lower in the positive group; whereas the frequencies of consumption of snack food and fried sweets, jelly and pudding, fried food, and butter, lard, and beef tallow were higher. The odds ratios for the fibrosis progression in patients who consumed fried food ≥4 times/week was 2.21. The positive group also showed lower physical activity level (PAL) and exercise (Ex, metabolic equivalents for tasks (METs)/hour/week). The patients who undertook Ex at >7.5 had an odds ratio of 0.21 for the fibrosis progression. (4) Conclusion: High consumption of fried food and low Ex are risk factors for the fibrosis progression in NAFLD.

The FibroScan-aspartate aminotransferase score can stratify the disease severity in a Japanese cohort with fatty liver diseases

This study aimed to prove that the FibroScan-aspartate aminotransferase (FAST) scores can be used to stratify disease severity in a Japanese cohort with fatty liver diseases [metabolic dysfunction-associated fatty liver disease (MAFLD) and nonalcoholic fatty liver disease (NAFLD)]. All the participants (n = 2254) underwent liver stiffness measurements and controlled attenuation parameter assessments. We compared the clinical characteristics of the patients with MAFLD and NAFLD using the FAST scores and explored the independent determinants of FAST scores ≥ 0.35, which indicated possible progressive disease. Overall, MAFLD was diagnosed in 789 patients (35.0%), while NAFLD was diagnosed in 618 (27.4%). The proportion of patients that had a condition that suggested progressive liver disease was higher in those with MAFLD than in those with NAFLD [68 (8.6%) vs 48 (7.7%)]. The area under the receiver-operating characteristic curve of the FAST score for diagnosing advanced fibrosis was 0.969 in MAFLD and 0.965 in NAFLD. Multivariate analyses determined that diabetes mellitus, alanine aminotransferase (ALT) levels, fatty liver index, and Fibrosis-4 index independently predict FAST scores ≥ 0.35 in patients with MAFLD. ALT levels had the strongest correlation with the FAST scores (p = 0.7817). The FAST score could stratify the disease severity in the Japanese cohort with fatty liver diseases.

Validation of the FibroScan-aspartate aminotransferase score by vibration-controlled transient and B-mode ultrasound elastography

AIM

The FibroScan-aspartate aminotransferase (FAST) score comprises an easy and feasible method for identifying advanced non-alcoholic steatohepatitis. Recently, shear-wave elastography and attenuation coefficient measurement on B-mode ultrasound (US) have become widely utilized. We investigated the diagnostic accuracy of the FAST score as calculated using US-elastography compared with that using vibration-controlled transient elastography (VCTE).

METHODS

Patients with chronic liver disease who underwent VCTE, point-shear-wave elastography with attenuation coefficient measurement, and liver biopsy on the same day between January 2015 and September 2020 were retrospectively reviewed.

RESULTS

Of 189 patients, 94 underwent VCTE using both M and XL probes. The C-statistics were similar for VCTE (0.846) and US-elastography (0.814; p = 0.251), and for M (0.857) and XL probes (0.833; p = 0.412). Scatter and Bland-Altman plots showed good reproducibility for the FAST score. For VCTE, a cut-off of ≤0.35 had a sensitivity of 92.3%, negative predictive value of 85.5%, and negative likelihood ratio of 0.14, and a cut-off of ≥0.67 had a specificity of 90.6%, positive predictive value of 88.1%, and positive likelihood ratio of 6.03, for ruling out and in advanced non-alcoholic steatohepatitis, respectively. For US-elastography, a cut-off of ≤0.35 had a sensitivity of 90.4%, negative predictive value of 83.3%, and negative likelihood ratio of 0.16, and a cutoff of ≥0.67 had a specificity of 91.8%, positive predictive value of 85.1%, and positive likelihood ratio of 4.67, for ruling out and in advanced non-alcoholic steatohepatitis, respectively.

CONCLUSIONS

The FAST score is highly reproducible, even when different echo equipment or probes are used.

Serum levels of soluble dipeptidyl peptidase-4 in type 2 diabetes are associated with severity of liver fibrosis evaluated by transient elastography (FibroScan) and the FAST (FibroScan-AST) score, a novel index of non-alcoholic steatohepatitis with significant fibrosis

AIM

To investigate the relationship in people with type 2 diabetes between serum soluble dipeptidyl peptidase-4 (sDDP-4) and degree of liver fibrosis assessed as the liver stiffness measurement (LSM) and FAST (FibroScan-AST) score, both of which were measured by transient elastography (FibroScan).

SUBJECTS AND METHODS

In this cross-sectional study, we examined 115 patients with type 2 diabetes. With transient elastography (FibroScan), we assessed the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) as measures of hepatic steatosis and liver fibrosis, respectively. We calculated the FAST score, which identifies progressive non-alcoholic steatohepatitis (NASH), from CAP, LSM, and the serum aspartate aminotransferase level. Significant hepatic steatosis was defined as CAP ≥280 dB/m; and significant liver fibrosis, as LSM ≥ 8.0 kPa. LSM was divided into 3 severity levels: significant fibrosis (8.0 to <9.7 kPa); advanced fibrosis, (9.7 to <13.0 kPa); and liver cirrhosis (≥ 13.0 kPa).

RESULTS

Serum sDPP-4 correlated positively with liver enzymes, CAP, LSM, and FAST score. Multivariate analysis showed that LSM remained to be an independent factor for serum sDDP-4. Serum sDPP-4 was significantly higher in patients with LSM ≥ 8.0 kPa than in those with LSM <8.0 kPa and was significantly elevated in patients who are at risk for non-alcoholic steatohepatitis (NASH) with fibrosis (FAST score ≥ 035 or 0.67). Patients with both hepatic steatosis and liver fibrosis had the highest serum sDPP-4.

CONCLUSION

Serum sDPP-4 was strongly associated with severity of liver fibrosis evaluated by LSM and the FAST score and was markedly elevated in diabetic patients with LSM ≥ 13.0 kPa indicating probable cirrhosis.

Two-dimensional shear wave elastography and ultrasound-guided attenuation parameter for progressive non-alcoholic steatohepatitis

BACKGROUND AND AIMS

We investigated the usefulness of combining two-dimensional shear wave elastography and the ultrasound-guided attenuation parameter for assessing the risk of progressive non-alcoholic steatohepatitis, defined as non-alcoholic steatohepatitis with a non-alcoholic fatty liver disease activity score of ≥4 and a fibrosis stage of ≥2.

METHODS

This prospective study included 202 patients with non-alcoholic fatty liver disease who underwent two-dimensional shear wave elastography, ultrasound-guided attenuation parameter, vibration-controlled transient elastography, the controlled attenuation parameter, and liver biopsy on the same day. Patients were grouped according to liver stiffness measurement using two-dimensional shear wave elastography and the attenuation coefficient, assessed using the ultrasound-guided attenuation parameter: A, low liver stiffness measurement/low attenuation coefficient; B, low liver stiffness measurement/high attenuation coefficient; C, high liver stiffness measurement/low attenuation coefficient; and D, high liver stiffness measurement/high attenuation coefficient.

RESULTS

Two-dimensional shear wave elastography and vibration-controlled transient elastography had equivalent diagnostic performance for fibrosis. The areas under the curve of the ultrasound-guided attenuation parameter for identifying steatosis grades ≥S1, ≥S2, and S3 were 0.89, 0.91, and 0.92, respectively, which were significantly better than those of the controlled attenuation parameter (P<0.05). The percentages of progressive non-alcoholic steatohepatitis in Groups A, B, C, and D were 0.0%, 7.7%, 35.7%, and 50.0%, respectively (P<0.001). The prediction model was established as logit (p) = 0.5414 × liver stiffness measurement (kPa) + 7.791 × attenuation coefficient (dB/cm/MHz)-8.401, with area under the receiver operating characteristic curve, sensitivity, and specificity values of 0.832, 80.9%, and 74.6%, respectively; there was no significant difference from the FibroScan-aspartate aminotransferase score.

CONCLUSION

Combined assessment by two-dimensional shear wave elastography and the ultrasound-guided attenuation parameter is useful for risk stratification of progressive non-alcoholic steatohepatitis and may be convenient for evaluating the necessity of specialist referral and liver biopsy.

FIB-4 First in the Diagnostic Algorithm of Metabolic-Dysfunction-Associated Fatty Liver Disease in the Era of the Global Metabodemic

The prevalence of obesity or metabolic syndrome is increasing worldwide (globally metabodemic). Approximately 25% of the adult general population is suffering from nonalcoholic fatty liver disease (NAFLD), which has become a serious health problem. In 2020, global experts suggested that the nomenclature of NAFLD should be updated to metabolic-dysfunction-associated fatty liver disease (MAFLD). Hepatic fibrosis is the most significant determinant of all cause- and liver -related mortality in MAFLD. The non-invasive test (NIT) is urgently required to evaluate hepatic fibrosis in MAFLD. The fibrosis-4 (FIB-4) index is the first triaging tool for excluding advanced fibrosis because of its accuracy, simplicity, and cheapness, especially for general physicians or endocrinologists, although the FIB-4 index has several drawbacks. Accumulating evidence has suggested that vibration-controlled transient elastography (VCTE) and the enhanced liver fibrosis (ELF) test may become useful as the second step after triaging by the FIB-4 index. The leading cause of mortality in MAFLD is cardiovascular disease (CVD), extrahepatic malignancy, and liver-related diseases. MAFLD often complicates chronic kidney disease (CKD), resulting in increased simultaneous liver kidney transplantation. The FIB-4 index could be a predictor of not only liver-related mortality and incident hepatocellular carcinoma, but also prevalent and incident CKD, CVD, and extrahepatic malignancy. Although NITs as milestones for evaluating treatment efficacy have never been established, the FIB-4 index is expected to reflect histological hepatic fibrosis after treatment in several longitudinal studies. We here review the role of the FIB-4 index in the management of MAFLD.

Diagnostic Accuracy of FibroScan and Factors Affecting Measurements

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

Magnetic resonance imaging for the assessment of pathological hepatic findings in nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease (NAFLD) is expected to increase because of the current epidemics of obesity and diabetes, and NAFLD has become a major cause of chronic liver disease worldwide. Liver fibrosis is associated with poor long-term outcomes in patients with NAFLD. Additionally, increased mortality and liver-related complications are primarily seen in patients with nonalcoholic steatohepatitis (NASH); however, nonalcoholic fatty liver (NAFL) is believed to be benign and non-progressive. Therefore, distinguishing between NASH and NAFL is clinically important. Liver biopsy is the gold standard method for the staging of liver fibrosis and distinguishing between NASH and NAFL. Unfortunately, liver biopsy is an invasive and expensive procedure. Therefore, noninvasive methods, to replace biopsy, are urgently needed for the staging of liver fibrosis and diagnosing NASH. In this review, we discuss the recent studies on magnetic resonance imaging (MRI), including magnetic resonance elastography, proton density fat fraction measurement, and multiparametric MRI (mpMRI) that can be used in the assessment of NASH components such as liver fibrosis, steatosis, and liver injury including inflammation and ballooning.

The Use of Transient Elastography Technology in the Bariatric Patient: a Review of the Literature

Transient elastography (TE) is a non-invasive technology that demonstrates promise in assessing liver steatosis and fibrosis without the risks of traditional percutaneous liver biopsy. Many studies have examined its reliability in respect to liver biopsy, but fewer have examined using TE in obese and bariatric surgery patients. With evidence showing that bariatric surgery can lead to improvement of liver steatosis and fibrosis, TE has the potential to provide a simple avenue of hepatic assessment in patients before and after procedures. This review article investigates what is known about the reliability of TE and its implementation in obese and bariatric surgery patients.

Advances in ultrasound elastography for nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) has increased rapidly worldwide, making NAFLD/NASH an important global health problem from both a medical and socioeconomic standpoint. NAFLD is also regarded as a liver component of metabolic syndrome and is reported to be associated with the risk factors for metabolic syndrome. It has been suggested that NAFLD/NASH be recognized both as a liver-specific disease and as an early mediator of systemic diseases. Liver biopsy is recommended as the gold standard method for the diagnosis of NASH and for the staging of liver fibrosis in patients with NAFLD. However, because of its high cost, high risk, and high weightage as a healthcare resource, invasive liver biopsy is a poorly suited diagnostic test for such a highly prevalent condition. Therefore, the development of reliable noninvasive methods for the assessment of liver fibrosis has been sought to estimate the risk of progression of NASH to cirrhosis, estimate the risk of cardiovascular events, aid in the surveillance for HCC, and guide therapy in patients with NAFLD/NASH. In this review, we highlight the principles and recent advances in ultrasound elastography techniques (Real-time Tissue Elastography^®, vibration-controlled transient elastography, point shear wave elastography, and two-dimensional shear wave elastography) used to evaluate the liver fibrosis stage and steatosis grade in patients with NAFLD.

Epidemiology: Pathogenesis, and Diagnostic Strategy of Diabetic Liver Disease in Japan

Type 2 diabetes (T2D) is closely associated with nonalcoholic fatty liver disease (NAFLD). Nonalcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to cirrhosis, hepatocellular carcinoma (HCC), and hepatic decompensation. Patients with T2D have twice the risk of HCC incidence compared with those without T2D. Because the hepatic fibrosis grade is the main determinant of mortality in patients with NAFLD, identifying patients with advanced fibrosis using non-invasive tests (NITs) or imaging modalities is crucial. Globally, the fibrosis-4 index (FIB-4 index), NAFLD fibrosis score, and enhanced liver fibrosis test have been established to evaluate hepatic fibrosis. Two-step algorithms using FIB-4 index as first triaging tool are globally accepted. It remains unknown which kinds of NITs or elastography are best as the second step tool. In Japan, type IV collagen 7s or the CA-fibrosis index (comprising type IV collagen 7s and aspartate aminotransferase (AST)) is believed to precisely predict advanced fibrosis in NAFLD. Patients with NAFLD who have high non-invasive test results should be screened for HCC or esophageal varices. Risk factors of rapid fibrosis progression in NAFLD includes age, severe obesity, presence of T2D, menopause in women, and a patatin-like phospholipase domain containing the 3 GG genotype. Patients with NAFLD who have these risk factors should be intensively treated with lifestyle modification or pharmacotherapies for preventing liver-related mortality.