Screening for compensated advanced chronic liver disease using refined Baveno VI elastography cutoffs in Asian patients with nonalcoholic fatty liver disease

Serum dithiothreitol-oxidizing capacity (DOC) is a promising biomarker for excluding significant liver fibrosis: a proof-of-concept study

BACKGROUND

APRI and FIB-4 scores are used to exclude clinically significant fibrosis (defined as stage ≥ F2) in patients with chronic viral hepatitis. However, the cut-offs for these scores (generated by Youden indices) vary between different patient cohorts. This study aimed to evaluate whether serum dithiothreitol-oxidizing capacity (DOC), i.e., a surrogate test of quiescin sulfhydryl oxidase-1, which is a matrix remodeling enzyme, could be used to non-invasively identify significant fibrosis in patients with various chronic liver diseases (CLDs).

METHODS

Diagnostic performance of DOC was compared with APRI and FIB-4 for identifying significant fibrosis. ROC curve analyses were undertaken in: a) two chronic hepatitis B (CHB) cohorts, independently established from hospitals in Wenzhou (n = 208) and Hefei (n = 120); b) a MASLD cohort from Wenzhou hospital (n = 122); and c) a cohort with multiple CLD etiologies (except CHB and MASLD; n = 102), which was identified from patients in both hospitals. Cut-offs were calculated using the Youden index. All CLD patients (n = 552) were then stratified by age for ROC curve analyses and cut-off calculations.

RESULTS

Stratified by CLD etiology or age, ROC curve analyses consistently showed that the DOC test was superior to APRI and FIB-4 for discriminating between clinically significant fibrosis and no fibrosis, when APRI and FIB-4 showed poor/modest diagnostic performance (P < 0.05, P < 0.01 and P < 0.001 in 3, 1 and 3 cohort comparisons, respectively). Conversely, the DOC test was equivalent to APRI and FIB-4 when all tests showed moderate/adequate diagnostic performances (P > 0.05 in 11 cohort comparisons). DOC had a significant advantage over APRI or FIB-4 scores for establishing a uniform cut-off independently of age and CLD etiology (coefficients of variation of DOC, APRI and FIB-4 cut-offs were 1.7%, 22.9% and 47.6% in cohorts stratified by CLD etiology, 2.0%, 26.7% and 29.5% in cohorts stratified by age, respectively). The uniform cut-off was 2.13, yielded from all patients examined. Surprisingly, the uniform cut-off was the same as the DOC upper limit of normal with a specificity of 99%, estimated from 275 healthy control individuals. Hence, the uniform cut-off should possess a high negative predictive value for excluding significant fibrosis in primary care settings. A high DOC cut-off with 97.5% specificity could be used for detecting significant fibrosis (≥ F2) with an acceptable positive predictive value (87.1%).

CONCLUSIONS

This proof-of-concept study suggests that the DOC test may efficiently rule out and rule in significant liver fibrosis, thereby reducing the numbers of unnecessary liver biopsies. Moreover, the DOC test may be helpful for clinicians to exclude significant liver fibrosis in the general population.

Gut symbionts alleviate MASH through a secondary bile acid biosynthetic pathway

The gut microbiota has been found to play an important role in the progression of metabolic dysfunction-associated steatohepatitis (MASH), but the mechanisms have not been established. Here, by developing a click-chemistry-based enrichment strategy, we identified several microbial-derived bile acids, including the previously uncharacterized 3-succinylated cholic acid (3-sucCA), which is negatively correlated with liver damage in patients with liver-tissue-biopsy-proven metabolic dysfunction-associated fatty liver disease (MAFLD). By screening human bacterial isolates, we identified Bacteroides uniformis strains as effective producers of 3-sucCA both in vitro and in vivo. By activity-based protein purification and identification, we identified an enzyme annotated as β-lactamase in B. uniformis responsible for 3-sucCA biosynthesis. Furthermore, we found that 3-sucCA is a lumen-restricted metabolite and alleviates MASH by promoting the growth of Akkermansia muciniphila. Together, our data offer new insights into the gut microbiota-liver axis that may be leveraged to augment the management of MASH.

Validating the Baveno Elastography Criteria of Advanced Liver Fibrosis in Two-Dimensional Shear Wave Elastography: A Prospective Pathology-Based Study

INTRODUCTION

The Baveno criteria for assessing advanced liver fibrosis were mainly determined by transient elastography (TE), and its pathology-based validation studies in two-dimensional shear wave elastography (2D-SWE) remain limited. We aimed to validate the Baveno criteria through use of 2D-SWE.

METHOD

Consecutive patients who underwent liver biopsies for various benign liver diseases were prospectively recruited. Liver stiffness measurement (LSM) was simultaneously evaluated by TE and 2D-SWE. The optimal cutoff value to predict advanced liver fibrosis was determined by the Youden Index, and the diagnostic performance was estimated using area under the receiver operating characteristic (AUROC) analysis.

RESULTS

A total of 101 patients were enrolled having a median age of 55.0 (IQR: 46.0-63.5) years, with 53 (52.48%) of them being male. Using <9 and >14 kPa as the optimal dual cutoffs, the AUROC values in TE and 2D-SWE were 0.92 (95% CI: 0.83-0.97) and 0.93 (95% CI: 0.84-0.98), respectively (p = 0.61). The sensitivity and specificity of LSM by TE/2D-SWE achieved rates of 94.44%/94.44% and 86.00%/88.00%, respectively. However, using the Baveno criteria, the AUROC values in TE and 2D-SWE could remain achieving 0.91 (95% CI: 0.82-0.97) and 0.93 (95% CI: 0.84-0.98), respectively (p = 0.36). The sensitivity and specificity in TE/2D-SWE were 88.24%/88.24% and 86.79%/90.57%, respectively.

CONCLUSION

This study establishes the compatibility of the Baveno dual cutoff criteria with 2D-SWE, positioning it as an easily used criteria in clinical practice and research.

Combination of Fibrosis-4, liver-stiffness measurement, and Fibroscan-AST score to predict liver-related outcomes in nonalcoholic fatty liver disease

INTRODUCTION

Noninvasive tests, such as Fibrosis-4 (FIB-4), liver-stiffness measurement (LSM) by vibration-controlled transient elastography, and Fibroscan-AST (FAST), are frequently used for risk stratification in NAFLD. The comparative performance of FIB-4 and LSM and FAST to predict clinical outcomes of patients with NAFLD remained unclear. We aim to evaluate the performance of FIB-4, LSM, and FAST scores to predict clinical outcomes in patients with NAFLD.

METHODS

We included consecutive adult patients with NAFLD with transient elastography performed between 2015 and 2022 from the United States and Singapore. Patients with NAFLD stratified based on baseline FIB-4, LSM, and FAST score were followed up until clinical outcomes notably liver-related events (LREs), LREs or death, death, and major adverse cardiac events.

RESULTS

A total of 1262 patients with NAFLD (63% with obesity and 37% with diabetes) with vibration-controlled transient elastography were followed up for median 3.5 years. FIB-4 stratified patients with NAFLD into low-risk (<1.3), intermediate-risk (1.3-2.67), and high-risk (>2.67) in 59.4%, 31.5%, and 9.1%, respectively. No LRE occurred with baseline FIB-4 <1.3, regardless of LSM and FAST score. Higher FIB-4 was associated with a higher risk of LREs within each LSM category. FIB-4 had a higher area under the received operating characteristic curve than LSM or FAST score to predict LRE.

CONCLUSIONS

In this multicenter international study, FIB-4 and LSM synergistically predicted the risk of LRE. In patients with FIB-4 <1.3, vibration-controlled transient elastography may incorrectly classify up to 10% of the patients as high risk. FIB-4 should be incorporated into risk stratification in NAFLD even among patients who underwent VCTE.

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.

Hepatocyte apoptosis fragment product cytokeratin-18 M30 level and non-alcoholic steatohepatitis risk diagnosis: an international registry study

BACKGROUND

Liver biopsy for the diagnosis of non-alcoholic steatohepatitis (NASH) is limited by its inherent invasiveness and possible sampling errors. Some studies have shown that cytokeratin-18 (CK-18) concentrations may be useful in diagnosing NASH, but results across studies have been inconsistent. We aimed to identify the utility of CK-18 M30 concentrations as an alternative to liver biopsy for non-invasive identification of NASH.

METHODS

Individual data were collected from 14 registry centers on patients with biopsy-proven non-alcoholic fatty liver disease (NAFLD), and in all patients, circulating CK-18 M30 levels were measured. Individuals with a NAFLD activity score (NAS) ≥5 with a score of ≥1 for each of steatosis, ballooning, and lobular inflammation were diagnosed as having definite NASH; individuals with a NAS ≤2 and no fibrosis were diagnosed as having non-alcoholic fatty liver (NAFL).

RESULTS

A total of 2571 participants were screened, and 1008 (153 with NAFL and 855 with NASH) were finally enrolled. Median CK-18 M30 levels were higher in patients with NASH than in those with NAFL (mean difference 177 U/L; standardized mean difference [SMD]: 0.87 [0.69-1.04]). There was an interaction between CK-18 M30 levels and serum alanine aminotransferase, body mass index (BMI), and hypertension ( P  < 0.001, P  = 0.026 and P  = 0.049, respectively). CK-18 M30 levels were positively associated with histological NAS in most centers. The area under the receiver operating characteristics (AUROC) for NASH was 0.750 (95% confidence intervals: 0.714-0.787), and CK-18 M30 at Youden's index maximum was 275.7 U/L. Both sensitivity (55% [52%-59%]) and positive predictive value (59%) were not ideal.

CONCLUSION

This large multicenter registry study shows that CK-18 M30 measurement in isolation is of limited value for non-invasively diagnosing NASH.

N-terminal propeptide of type 3 collagen-based sequential algorithm can identify high-risk steatohepatitis and fibrosis in MAFLD

BACKGROUND AND AIMS

With metabolic dysfunction-associated fatty liver disease (MAFLD) incidence and prevalence sharply increasing globally, there is an urgent need for non-invasive diagnostic tests to accurately screen high-risk MAFLD patients for liver inflammation and fibrosis. We aimed to develop a novel sequential algorithm based on N-terminal propeptide of type 3 collagen (PRO-C3) for disease risk stratification in patients with MAFLD.

METHODS

A derivation and independent validation cohort of 327 and 142 patients with biopsy-confirmed MAFLD were studied. We compared the diagnostic performances of various non-invasive scores in different disease states, and a novel sequential algorithm was constructed by combining the best performing non-invasive scores.

RESULTS

For patients with high-risk progressive steatohepatitis (i.e., steatohepatitis + NAFLD activity score ≥ 4 + F ≥ 2), the AUROC of FAST score was 0.801 (95% confidence interval (CI): 0.739-0.863), and the negative predictive value (NPV) was 0.951. For advanced fibrosis (≥ F3) and cirrhosis (F4), the AUROCs of ADAPT and Agile 4 were 0.879 (95%CI 0.825-0.933) and 0.943 (95%CI 0.892-0.994), and the NPV were 0.972 and 0.992. Sequential algorithm of ADAPT + Agile 4 combination was better than other combinations for risk stratification of patients with severe fibrosis (AUROC = 0.88), with similar results in the validation cohort. Meanwhile, in all subgroup analyses (stratifying by sex, age, diabetes, NAS, BMI and ALT), ADAPT + Agile 4 had a good diagnostic performance.

CONCLUSIONS

The new sequential algorithm reliably identifies liver inflammation and fibrosis in MAFLD, making it easier to exclude low-risk patients and recommending high-risk MAFLD patients for clinical trials and emerging pharmacotherapies.

Dissecting the multifaceted impact of statin use on fatty liver disease: a multidimensional study

BACKGROUND

Statin use could benefit patients with non-alcoholic fatty liver disease (NAFLD), but the evidence is segmented and inconclusive. This multidimensional study comprehensively investigated the potential benefits and mechanism-of-action of statins in NAFLD.

METHODS

A cross-sectional investigation was performed within the Rotterdam Study (general population; n = 4.576) and the PERSONS cohort (biopsy-proven NAFLD patients; n = 569). Exclusion criteria were secondary causes for steatosis and insufficient data on alcohol, dyslipidemia or statin use. Associations of statin use with NAFLD (among entire general population), fibrosis and NASH (among NAFLD individuals and patients) were quantified. These results were pooled with available literature in meta-analysis. Last, we assessed statins' anti-lipid and anti-inflammatory effects in 3D cultured human liver organoids and THP-1 macrophages, respectively.

FINDINGS

Statin use was inversely associated with NAFLD in the Rotterdam study compared to participants with untreated dyslipidemia. In the PERSONS cohort, statin use was inversely associated with NASH, but not with fibrosis. The meta-analysis included 7 studies and indicated a not significant inverse association for statin use with NAFLD (pooled-Odds Ratio: 0.69, 95% Confidence Interval: 0.46-1.01) and significant inverse associations with NASH (pooled-OR: 0.59, 95% CI: 0.44-0.79) and fibrosis (pooled-OR: 0.48, 95% CI: 0.33-0.70). In vitro, statins significantly reduced lipid droplet accumulation in human liver organoids and downregulated expression of pro-inflammatory cytokines in macrophages.

INTERPRETATION

Pooled results demonstrated that statin use was associated with a lower prevalence of NASH and fibrosis and might prevent NAFLD. This may be partially attributed to the anti-lipid and anti-inflammatory characteristics of statins. Given their under-prescription, adequate prescription of statins may limit the disease burden of NAFLD.

FUNDING

ZonMw, KWF, NWO, SLO, DGXII, RIDE, National and regional government, Erasmus MC and Erasmus University.

Non-alcoholic fatty liver disease screening in type 2 diabetes mellitus: A cost-effectiveness and price threshold analysis

Introduction: The cost-effectiveness of screening asymptomatic non-alcoholic fatty liver disease (NAFLD) patients remains debatable, with current studies assuming lifelong benefits of NAFLD screening while neglecting cardiovascular outcomes. This study aims to assess the cost-effectiveness of NAFLD screening among type 2 diabetes mellitus (T2DM) patients, and to establish a price threshold for NAFLD treatment, when it becomes available. Method: A Markov model was constructed comparing 4 screening strategies (versus no screening) to identify NAFLD with advanced fibrosis among T2DM patients: fibrosis-4 (FIB-4), vibration-controlled transient elastography (VCTE), FIB-4 and VCTE (simultaneous), and FIB-4 and VCTE (sequential). Sensitivity analyses and price threshold analyses were performed to assess parameter uncertainties in the results. Results: VCTE was the most cost-effective NAFLD screening strategy (USD24,727/quality-adjusted life year [QALY]), followed by FIB-4 (USD36,800/QALY), when compared to no screening. Probabilistic sensitivity analysis revealed a higher degree of certainty for VCTE as a cost-effective strategy compared to FIB-4 (90.7% versus 73.2%). The duration of expected screening benefit is the most influential variable based on incremental cost-effectiveness ratio tornado analysis. The minimum duration of screening benefit for NAFLD screening to be cost-effective was at least 2.6 years. The annual cost of NAFLD treatment should be less than USD751 for NAFLD screening to be cost-effective. Conclusion: Both VCTE and FIB-4 are cost-effective NAFLD screening strategies among T2DM patients in Singapore. However, given the lack of access to VCTE at primacy care and potential budget constraints, FIB-4 can also be considered for NAFLD screening among T2DM patients in Singapore. Keywords: Cost-effectiveness analysis, fatty liver, screening, liver fibrosis, population health

Gut bacteria alleviate smoking-related NASH by degrading gut nicotine

Tobacco smoking is positively correlated with non-alcoholic fatty liver disease (NAFLD)^1-5, but the underlying mechanism for this association is unclear. Here we report that nicotine accumulates in the intestine during tobacco smoking and activates intestinal AMPKα. We identify the gut bacterium Bacteroides xylanisolvens as an effective nicotine degrader. Colonization of B. xylanisolvens reduces intestinal nicotine concentrations in nicotine-exposed mice, and it improves nicotine-exacerbated NAFLD progression. Mechanistically, AMPKα promotes the phosphorylation of sphingomyelin phosphodiesterase 3 (SMPD3), stabilizing the latter and therefore increasing intestinal ceramide formation, which contributes to NAFLD progression to non-alcoholic steatohepatitis (NASH). Our results establish a role for intestinal nicotine accumulation in NAFLD progression and reveal an endogenous bacterium in the human intestine with the ability to metabolize nicotine. These findings suggest a possible route to reduce tobacco smoking-exacerbated NAFLD progression.

Comparison of screening strategies with two new tests to score and diagnose varices needing treatment

BACKGROUND AND AIMS

We aimed to improve non-invasive screening of varices needing treatment (VNT) and compare different screening strategies.

METHODS

2,290 patients with chronic liver disease were included in a retrospective study. Etiologies were: virus: 50.0%, NAFLD: 29.5%, alcohol: 20.5%, VNT: 14.9%. Test descriptors were performance (spared endoscopy) and safety (missed VNT). VNT tests were evaluated according to their safety levels either for individual screening (95% negative predictive value (NPV)), population screening (95% sensitivity) or undifferentiated screening (100% sensitivity/NPV) without missed VNT. The tests provided three categories: missed VNT <5%, VNT 100% specificity (new category), both sparing endoscopies, and intermediate (endoscopy required).

RESULTS

Independent VNT predictors (etiology, sex, age, platelets, prothrombin index, albumin, ALT, liver stiffness) were included in two tests: VNT virus alcohol NAFLD test (VANT) and varice risk score (VARS). We report results of the whole population. Considering population screening, performances were, Baveno VI criteria: 24.1%, Anticipate: 24.7%, VariScreen: 35.3%, VANT: 40.2% (p<0.001 vs other tests). VANT spared 58.0% more endoscopies in the whole population than Baveno criteria in compensated advanced chronic liver diseases. Considering individual screening, VARS performance was, in all patients: 62.0% vs 42.9% for the expanded Baveno VI criteria (p<0.001), and, in NAFLD: 72.8% vs 65.1% for the NAFLD cirrhosis criteria (p<0.001). Considering undifferentiated screening, VARS performance was 12%. The VARS score estimated VNT probability from 0 to 100% (AUROC: 0.826).

CONCLUSION

VANT and VARS spared from 12% (undifferentiated screening) to 40% (population screening) or 62% (individual screening) of endoscopies in main-etiology patients without ascites.

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

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

A novel quantitative ultrasound technique for identifying non-alcoholic steatohepatitis

BACKGROUND AND AIMS

There remains a need to develop a non-invasive, accurate and easy-to-use tool to identify patients with non-alcoholic steatohepatitis (NASH). Successful clinical and preclinical applications demonstrate the ability of quantitative ultrasound (QUS) techniques to improve medical diagnostics. We aimed to develop and validate a diagnostic tool, based on QUS analysis, for identifying NASH.

METHODS

A total of 259 Chinese individuals with biopsy-proven non-alcoholic fatty liver disease (NAFLD) were enrolled in the study. The histological spectrum of NAFLD was classified according to the NASH clinical research network scoring system. Radiofrequency (RF) data, raw data of iLivTouch, was acquired for further QUS analysis. The least absolute shrinkage and selection operator (LASSO) method was used to select the most useful predictive features.

RESULTS

Eighteen candidate RF parameters were reduced to two significant parameters by shrinking the regression coefficients with the LASSO method. We built a novel QUS score based on these two parameters, and this QUS score showed good discriminatory capacity and calibration for identifying NASH both in the training set (area under the ROC curve [AUROC]: 0.798, 95% confidence interval [CI] 0.731-0.865; Hosmer-Lemeshow test, P = .755) and in the validation set (AUROC: 0.816, 95% CI 0.725-0.906; Hosmer-Lemeshow test, P = .397). Subgroup analysis showed that the QUS score performed well in different subgroups.

CONCLUSIONS

The QUS score, which was developed from QUS, provides a novel, non-invasive and practical way for identifying NASH.

Peripheral immune cells in NAFLD patients: A spyhole to disease progression

Nonalcoholic fatty liver disease (NAFLD) is a worldwide leading cause of chronic liver disease, but we still lack ideal non-invasive tools for diagnosis and evaluation of nonalcoholic steatohepatitis (NASH) and related liver fibrosis in NAFLD population. Systemic immune dysregulations such as metabolic inflammation are believed to play central role in the development of NAFLD, signifying the hope of utilizing quantitative and phenotypic changes in peripheral immune cells among NAFLD patients as a diagnostic tool of NASH and fibrosis. In this review, we summarize the known changes in peripheral immune cells from NAFLD/NASH patients and their potential relationship with NAFLD and NASH progression. Potential challenges and possible solutions for further clinical translation are also discussed.

acNASH index to diagnose nonalcoholic steatohepatitis: a prospective derivation and global validation study

BACKGROUND

There is an unmet need for non-invasive biomarkers for the diagnosis of nonalcoholic steatohepatitis (NASH) in non-specialized settings. We aimed to develop and validate a non-invasive test for diagnosing NASH in individuals with biopsy-proven nonalcoholic fatty liver disease (NAFLD).

METHODS

We developed a non-invasive test named the acNASH index that combines serum creatinine and aspartate aminotransferase levels in a derivation cohort of 390 Chinese NAFLD patients admitted to the hepatology center of the First Affiliated Hospital of Wenzhou Medical University (China) between December 2016 and September 2019 and subsequently validated in five external cohorts of different ethnicities of patients with biopsy-confirmed NAFLD (pooled n=1,089).

FINDINGS

The performance of the acNASH index for identifying NASH (defined as NAFLD activity score ≥5 with score of ≥1 for each steatosis, lobular inflammation and ballooning) was good in the derivation cohort with an area under receiver operating characteristics (AUROC) of 0·818 (95%CI 0·777-0·860). A cutoff of acNASH index <4·15 gave a sensitivity (Se) of 91%, a specificity (Sp) of 48% and a negative predictive value (NPV) of 83% for ruling-out NASH, conversely, a cutoff of acNASH >7·73 gave a Sp of 91%, Se of 53% and a positive predictive value (PPV) of 85% for ruling-in NASH. In the pooled validation cohort (n=1,089), the diagnostic performance of the index was also good with AUROC=0·805 (95%CI 0·780-0·830), NPV of 93% for ruling-out NASH and PPV of 73% for ruling-in NASH. Subgroup analyses showed similar performance in patients with diabetes or subjects with normal serum transaminase levels.

INTERPRETATION

The acNASH index shows promising utility as a simple non-invasive biomarker for diagnosing NASH among adults with biopsy-proven NAFLD of different ethnicities from different countries.

FUNDING

The National Natural Science Foundation of China (82070588), High Level Creative Talents from Department of Public Health in Zhejiang Province (S2032102600032) and Project of New Century 551 Talent Nurturing in Wenzhou.