FibroScan-aspartate aminotransferase score in an Asian cohort of non-alcoholic fatty liver disease and its utility in predicting histological resolution with bariatric surgery

FibroScan-AST score for diagnosing fibrotic MASH: A systematic review and meta-analysis of diagnostic test accuracy studies

BACKGROUND AND AIM

Following the approval of the first agent for the management of metabolic dysfunction-associated steatohepatitis (MASH), identification of patients with fibrotic MASH (MASH with NAS ≥ 4 and fibrosis stage ≥ 2) is crucial. We assessed the performance of FibroScan-aspartate aminotransferase (AST) score (FAST) for ruling in/out fibrotic MASH.

METHODS

We searched Medline, Cochrane Library, Web of Science, Scopus, and gray literature sources up to January 11, 2024. Studies were eligible if they assessed the accuracy of FAST score for the detection of fibrotic MASH using biopsy as the reference standard at previously reported thresholds (FAST ≥ 0.67 for ruling-in and ≤ 0.35 for ruling-out fibrotic MASH). We calculated pooled sensitivity and specificity estimates for FAST thresholds alongside 95% confidence intervals following bivariate random- effects models. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework.

RESULTS

We included 16 studies with 8838 participants. A FAST score ≥ 0.67 yielded a pooled specificity of 0.87 (0.82-0.90) while a FAST score ≤ 0.35 yielded a summary sensitivity of 0.88 (0.83-0.91). At a prevalence of 30%, the positive predictive value for ruling-in fibrotic MASH was 60% while the negative predictive value for ruling-out the target condition was 91%. AST levels, cirrhosis prevalence, and number of pathologists reviewing biopsies were sources of heterogeneity among studies. The certainty of evidence was low to very low.

CONCLUSIONS

FAST score can be used as a triage test for ruling out fibrotic MASH. Nevertheless, its low positive predictive value necessitates sequential testing for ruling-in fibrotic MASH.

WFUMB Guidelines/Guidance on Liver Multiparametric Ultrasound. Part 2: Guidance on Liver Fat Quantification

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has promoted the development of this document on multiparametric ultrasound. Part 2 is a guidance on the use of the available tools for the quantification of liver fat content with ultrasound. These are attenuation coefficient, backscatter coefficient, and speed of sound. All of them use the raw data of the ultrasound beam to estimate liver fat content. This guidance has the aim of helping the reader in understanding how they work and interpret the results. Confounding factors are discussed and a standardized protocol for measurement acquisition is suggested to mitigate them. The recommendations were based on published studies and experts' opinion but were not formally graded because the body of evidence remained low at the time of drafting this document.

Lean Indian patients with non-alcoholic fatty liver disease (NAFLD) have less metabolic risk factors but similar liver disease severity as non-lean patients with NAFLD

INTRODUCTION

Although most patients with NAFLD are obese or overweight, some are lean with normal BMI. Our aim was to assess differences in clinicopathological profile and liver disease severity among lean and non-lean NAFLD.

METHODS

Data of 1040 NAFLD patients over last 10 years was analysed. BMI < 23 kg/m2 categorised lean patients. Non-invasive assessment of steatosis was done by ultrasound and controlled attenuation parameter (CAP) while fibrosis was assessed with FIB-4 and liver stiffness measurement (LSM). FibroScan-AST (FAST) score was used for non-invasive prediction of NASH with significant fibrosis. Histology was reported using NASH-CRN system.

RESULTS

149 (14.3%) patients were lean while 891 (85.7%) patients were non-lean. Diabetes mellitus [25 (16.7%) vs 152 (17.05%), p > 0.99], elevated triglycerides [81 (54.3%) vs 525 (58.9%), p = 0.33] and low HDL [71(47.6%) vs 479(53.7%), p = 0.18] were observed in a similar proportion. Lean patients were less likely to have central obesity [72 (48.3%) vs 788 (88.4%), p < 0.001], hypertension [16 (10.7%) vs 239(26.8%), p < 0.001] and metabolic syndrome [21 (14.09%) vs 290 (32.5%), p < 0.001]. No difference in steatosis assessment was noted using ultrasound (p = 0.55) or CAP (0.11). FAST [0.38 (0.18-0.66) vs 0.39 (0.27-0.73), p = 0.53], FIB-4 [1.08 (0.65-1.91) vs 1.09 (0.66-1.94), p = 0.94] and LSM [6.1 (4.8-7.9) vs 6.2 (4.7-8.6), p = 0.19) were similar. Liver biopsy was available in 149 patients [lean: 19 (12.7%), non-lean: 130 (87.3%)]. There was no difference in the number of patients with NASH [4 (21.05%) vs 20 (15.3%), p = 0.51], significant fibrosis [2 (10.5%) vs 32 (24.6%), p = 0.25] or advanced fibrosis [1 (5.26%) vs 18 (13.84%), p = 0.47].

CONCLUSION

Although metabolic co-morbidities are less common, there is no difference in liver disease severity among both groups.

ABDA Score: A Non-invasive Model to Identify Subjects with Fibrotic Non-alcoholic Steatohepatitis in the Community

Background

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH) are prevalent in the community, especially among those with metabolic syndrome. Patients with fibrotic NASH are at increased risk of liver-related-events. Currently available non-invasive tests have not been utilized for screening for fibrotic NASH among the community. We aimed to develop a screening tool for fibrotic NASH among community members.

Methods

We included two large cohorts aimed at assessing cardiovascular disease among community members. Fibrotic NASH was defined using the FibroScan-aspartate aminotransferase score of ≥0.67 that identifies ≥F2 fibrosis and a non-alcoholic fatty liver disease activity score ≥4 with a specificity of 90%. Metabolic parameters, biochemical tests and anthropometry were used to develop a multivariate model.

Results

The derivation cohort (n = 1660) included a population with a median age 45 years, 42.5% males, metabolic syndrome in 66% and 2.7% (n = 45) with fibrotic NASH. Multivariate analysis identified the four significant variables (Age, body mass index , Diabetes and alanine aminotransferas levels) used to derive an ABDA score. The score had high diagnostic accuracy (the area under receiver-operating characteristic curve, 0.952) with adequate internal validity. An ABDA score ≥-3.52 identified fibrotic NASH in the derivation cohort with a sensitivity and specificity of 88.9% and 88.3%. The score was validated in a second cohort (n = 357) that included 21 patients (5.9%) with fibrotic NASH, where it demonstrated a high area under receiver-operating characteristic curve (0.948), sensitivity (81%) and specificity (89.3%).

Conclusions

ABDA score utilizes four easily available parameters to identify fibrotic NASH with high accuracy in the community.

Indian National Association for Study of the Liver (INASL) Guidance Paper on Nomenclature, Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease globally and in India. The already high burden of NAFLD in India is expected to further increase in the future in parallel with the ongoing epidemics of obesity and type 2 diabetes mellitus. Given the high prevalence of NAFLD in the community, it is crucial to identify those at risk of progressive liver disease to streamline referral and guide proper management. Existing guidelines on NAFLD by various international societies fail to capture the entire landscape of NAFLD in India and are often difficult to incorporate in clinical practice due to fundamental differences in sociocultural aspects and health infrastructure available in India. A lot of progress has been made in the field of NAFLD in the 7 years since the initial position paper by the Indian National Association for the Study of Liver on NAFLD in 2015. Further, the ongoing debate on the nomenclature of NAFLD is creating undue confusion among clinical practitioners. The ensuing comprehensive review provides consensus-based, guidance statements on the nomenclature, diagnosis, and treatment of NAFLD that are practically implementable in the Indian setting.

Compensated Advanced Chronic Liver Disease in Nonalcoholic Fatty Liver Disease: Two-Step Strategy is Better than Baveno Criteria

BACKGROUND

Advanced fibrosis and cirrhosis (compensated advanced chronic liver disease [cACLD]) are clinically indistinguishable and increase risk of developing clinically significant portal hypertension. Baveno VII recommends using elastography to rule out and diagnose cACLD with liver stiffness measurement (LSM) cut-offs of 10/15 kPa.

METHODS

In a retrospective analysis of 330 nonalcoholic fatty liver disease (NAFLD) patients, performance of the Baveno VII cut-offs for diagnosing cACLD was compared with newly suggested lower cut-offs (8/12 kPa). A model for detecting cACLD among those with LSM between 8 and 12 kPa was developed and compared with recently published models.

RESULTS

Seventy (21.2%) of the 330 NAFLD patients had biopsy-proven cACLD. The Baveno VII cut-offs (10/15 kPa) had a lower sensitivity of 72.8% (60.9-82.8%) and a specificity of 93.4% (89.7-96.1%). Sensitivity and specificity of lower cut-offs (8/12 kPa) were 91.4% (82.3-96.8%) and 88.5% (83.9-92.1%), respectively. Modeling based on the presence of diabetes (odds ratio [OR] 3.625[1.161-11.320], p = 0.027) and serum aspartate aminotransferase (AST) levels (OR 1.636[1.098-2.436], p = 0.015) correctly identified 75.7% of patients with LSM between 8 and 12 kPa. Our model performed best with an area under receiver operator curve (AUROC) of 0.725 (95%CI 0.609-0.822), compared to Papatheodoridi (AUROC 0.626, CI 0.506-.736) and Zhou (AUROC 0.523, CI 0.403-0.640) models. A two-step strategy comprising application of lower LSM cut-offs followed by the predictive model correctly identified the presence of cACLD in 83% of the patients as compared to 75% by the Baveno VII cut-offs.

CONCLUSION

A two-step strategy employing lower LSM cut-offs and modeling based on diabetes and AST levels outperforms Baveno VII cut-offs for identifying cACLD in NAFLD patients.

A metagenomic study identifies a Prevotella copri enriched microbial profile associated with non-alcoholic steatohepatitis in subjects with obesity

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease. Increasing evidence indicates that the gut microbiota can play an important role in the pathophysiology of NAFLD. Recently, several studies have tested the predictive value of gut microbiome profiles in NAFLD progression; however, comparisons of microbial signatures in NAFLD or non-alcoholic steatohepatitis (NASH) have produced discrepant results, possibly due to ethnic and environmental factors. Thus, we aimed to characterize the gut metagenome composition of patients with fatty liver disease.

METHODS

Gut microbiome of 45 well-characterized patients with obesity and biopsy-proven NAFLD was evaluated using shot-gun sequencing: 11 non-alcoholic fatty liver controls (non-NAFL), 11 with fatty liver, and 23 with NASH.

RESULTS

Our study showed that Parabacteroides distasonis and Alistipes putredenis were enriched in fatty liver but not in NASH patients. Notably, in a hierarchical clustering analysis, microbial profiles were differentially distributed among groups, and membership to a Prevotella copri dominant cluster was associated with a greater risk of developing NASH. Functional analyses showed that although no differences in LPS biosynthesis pathways were observed, Prevotella-dominant subjects had higher circulating levels of LPS and a lower abundance of pathways encoding butyrate production.

CONCLUSIONS

Our findings suggest that a Prevotella copri dominant bacterial community is associated with a greater risk for NAFLD disease progression, probably linked to higher intestinal permeability and lower capacity for butyrate production.

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.

Incidence and Predictors of Liver-Related Events in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the commonest type of liver disease worldwide. We aimed to assess the incidence and predictors of liver-related events (LREs) and mortality in NAFLD patients.

METHODS

NAFLD patients (n = 957) evaluated between January 2000 and November 2021 were included. Patients were categorised as noncirrhosis (NC), compensated cirrhosis (CC) and decompensated cirrhosis (DC), and the incidence of LRE and mortality were estimated and compared.

RESULTS

The proportions of NC, CC and DC were 87.8% (n = 840), 8.8% (n = 84) and 3.4% (n = 33), respectively. The median follow-up duration was 3.9 (3.0-5.7) years, and the total cumulative duration was 4633 person-years. The incidence of LRE per 100 person-years was 0.14, 2.72 and 10.24 in patients with NC, CC and DC, respectively. The incidence of mortality was 0.12, 1.05 and 4.24 per 100 person-years, respectively, in the 3 groups. The causes of mortality in the 3 groups were liver related in 1/5 (20%), 3/4 (75%) and 6/9 (66.7%), respectively. Overall, the mortality rate was higher in those with diabetes than those without diabetes (log-rank P value = 0.005). On further analysis, diabetes was associated with poor outcomes only in NC group (log-rank P value = 0.036), and not in CC (log-rank P value = 0.353) or DC groups (log-rank P value = 0.771). On multivariate Cox proportional hazard analysis, age (hazard ratio [HR] 1.070), hypertension (HR 4.361) and DC (HR 15.036) were independent predictors of poor outcomes. Liver stiffness measurement, bilirubin, CC and DC were independent predictors of LRE.

CONCLUSION

In our study of NAFLD from India, the incidence of LRE was found to be similar to that seen in Western studies. In NC NAFLD, diabetes was associated with poor outcomes.

Endoscopic Bariatric Treatment with Duodenal-Jejunal Bypass Liner Improves Non-invasive Markers of Non-alcoholic Steatohepatitis

Purpose

People with obesity often develop non-alcoholic fatty liver disease (NAFLD) and are at high risk of progression to non-alcoholic steatohepatitis (NASH). Few therapies are effective other than bariatric surgery. We therefore analyzed data from duodenal-jejunal bypass liner (DJBL) patients regarding steatosis, fibrosis, and NASH.

Methods

Consecutive DJBL patients with type 2 diabetes underwent standardized assessments up to device removal at 48 weeks. These included aspartate and alanine transaminase (AST, ALT), controlled attenuation parameter (CAP, for steatosis), and liver stiffness measurement (LSM, for fibrosis). The NAFLD fibrosis score (NFS), fibrosis-4 score (FIB4), and enhanced liver fibrosis (ELF) test were also used to assess fibrosis and the Fibroscan-AST (FAST) score to assess NASH. Mixed models were used and missing data were accounted for with multiple imputation.

Results

Thirty-two patients (18 female, mean age 55.1, mean BMI 40.2 kg/m²) were included. After 48 weeks, the change compared to baseline with 95% CI was a factor 0.74 (0.65 to 0.84) for AST, 0.63 (0.53 to 0.75) for ALT, and a difference of − 0.21 (− 0.28 to − 0.13) for FAST, all with p < 0.001. Fibrosis based on LSM, NFS, and ELF did not change whereas FIB4 exhibited slight improvement. Eight DJBL were explanted early due to device-related complications and eight complications led to hospitalization.

Conclusions

One year of DJBL therapy is associated with relevant improvements in non-invasive markers of steatosis and NASH, but not fibrosis, and is accompanied by a substantial number of complications. Given the lack of alternatives, DJBL deserves further attention.

Graphical abstract

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

BACKGROUND AND AIMS

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

FibroScan-AST (FAST) Score for Nonalcoholic Steatohepatitis - Validation in an Indian Cohort

Background

The FibroScan-AST (FAST) score was recently described to detect patients with nonalcoholic steatohepatitis (NASH) having elevated nonalcoholic fatty liver disease (NAFLD) activity score (NAS ≥ 4) and significant fibrosis (≥ F2) on liver biopsy (NASH+ NAS ≥ 4 + F ≥ 2).

Aim

The aim of this study was to validate the FAST score in Indian patients with NAFLD and to derive optimal cut-offs.

Methods

Sixty patients with biopsy-proven NAFLD [men: 38 (63.3%), age 40 (32-52) years] with all parameters for assessing the FAST score within 3 months of liver histology were retrospectively analysed.

Results

Histological NASH was present in 17 patients (28.3%), while 11 (18.3%) patients had NASH + NAS ≥ 4 + F ≥ 2. The area under the curve (AUROC) of the FAST score for discriminating NASH + NAS ≥ 4 + F ≥ 2 was 0.81. Using cut-offs by Newsome et al, the rule-out cut-off (FAST: ≤ 0.35) had a negative predictive value (NPV) of 0.88 [sensitivity: 0.91, specificity: 0.14, negative likelihood ratio (LR): 0.64], while the rule-in cut-off (FAST: ≥ 0.67) had a positive predictive value (PPV) of 0.33 (sensitivity: 0.73, specificity: 0.67, positive LR: 2.22). Fifteen (25%) patients were correctly classified as per histology, while 28 (46.67%) patients fell in the grey zone. On recalculating the optimal cut-offs for our patients, the rule-out cut-off (FAST: ≤ 0.55) had an NPV of 0.95 (sensitivity: 0.90, specificity: 0.45, negative LR: 0.21), while the optimal rule-in cut-off (FAST: ≥ 0.78) had a PPV of 0.70 (sensitivity: 0.64, specificity 0.94, positive LR: 10.39). With these cut-offs, 27 (45%) patients fell in the grey zone and 29 (48.3%) were correctly classified as per histology, performing better than the cut-offs by Newsome et al (P < 0.001).

Conclusion

The FAST score demonstrates good AUROC for detecting NASH with significant fibrosis and inflammation on histology. Cut-offs should be recalibrated based on prevalence of disease.

Lay summary

India has a high burden of NAFLD with an estimated 25 million patients at potential risk for significant liver disease. Liver biopsy remains the gold standard for diagnosing NASH, although its application in routine clinical practice is limited. Noninvasive tests for the simultaneous detection of steatosis, inflammation and fibrosis are thus the need of the hour. The FAST score has been recently suggested for the noninvasive detection of NASH with significant fibrosis (≥ F2) and inflammation (NAS ≥ 4) on liver biopsy. We validated the utility of the FAST score for detecting NASH with significant fibrosis and inflammation on liver biopsy in Indian patients with NAFLD. This noninvasive, easy-to-use and nonproprietary FAST score can correctly classify disease severity in more than 50% patients. However, our results suggest that cut-offs should be recalibrated based on the anticipated prevalence of NASH + NAS ≥ 4 + F ≥ 2 in the given population.