New scoring system combining the FIB-4 index and cytokeratin-18 fragments for predicting steatohepatitis and liver fibrosis in patients with nonalcoholic fatty liver disease

Machine learning algorithm improves the detection of NASH (NAS-based) and at-risk NASH: A development and validation study

BACKGROUND AND AIMS

Detecting NASH remains challenging, while at-risk NASH (steatohepatitis and F≥ 2) tends to progress and is of interest for drug development and clinical application. We developed prediction models by supervised machine learning techniques, with clinical data and biomarkers to stage and grade patients with NAFLD.

APPROACH AND RESULTS

Learning data were collected in the Liver Investigation: Testing Marker Utility in Steatohepatitis metacohort (966 biopsy-proven NAFLD adults), staged and graded according to NASH CRN. Conditions of interest were the clinical trial definition of NASH (NAS ≥ 4;53%), at-risk NASH (NASH with F ≥ 2;35%), significant (F ≥ 2;47%), and advanced fibrosis (F ≥ 3;28%). Thirty-five predictors were included. Missing data were handled by multiple imputations. Data were randomly split into training/validation (75/25) sets. A gradient boosting machine was applied to develop 2 models for each condition: clinical versus extended (clinical and biomarkers). Two variants of the NASH and at-risk NASH models were constructed: direct and composite models.Clinical gradient boosting machine models for steatosis/inflammation/ballooning had AUCs of 0.94/0.79/0.72. There were no improvements when biomarkers were included. The direct NASH model produced AUCs (clinical/extended) of 0.61/0.65. The composite NASH model performed significantly better (0.71) for both variants. The composite at-risk NASH model had an AUC of 0.83 (clinical and extended), an improvement over the direct model. Significant fibrosis models had AUCs (clinical/extended) of 0.76/0.78. The extended advanced fibrosis model (0.86) performed significantly better than the clinical version (0.82).

CONCLUSIONS

Detection of NASH and at-risk NASH can be improved by constructing independent machine learning models for each component, using only clinical predictors. Adding biomarkers only improved the accuracy of fibrosis.

Visceral Obesity and Cytokeratin-18 Antigens as Early Biomarkers of Liver Damage

Visceral obesity is linked to the progression of fatty liver to nonalcoholic steatohepatitis (NASH). Cytokeratin-18 (CK18) epitopes M30 (CK18M30) and M65 (CK18M65) represent accurate markers for detecting NASH. The aim of this study was to evaluate the association of CK18M30 and CK18M65 levels with anthropometric and metabolic characteristics, liver stiffness, and liver indices of steatosis and fibrosis in a cohort of subjects with visceral obesity; in this cross-sectional study, transient elastography (TE-Fibroscan^®), anthropometric measurements, metabolic parameters, High Sensitivity C-Reactive Protein (hsCRP), and CK18M30 and CK18M65 levels (Apoptosense ELISA, PEVIVA, Germany) were evaluated. Fatty Liver Index (FLI), Fibrosis 4 (FIB-4), and Aspartate transaminase (AST)-platelet ratio index (APRI) were calculated; among 48 subjects, 47.2% presented metabolic syndrome, 93.8% hepatic steatosis, 60.4% high liver stiffness, and 14.6% hypertransminasemia, while FIB-4 and APRI were normal. CK18M30 and CK18M65 levels were significantly correlated with waist circumference, AST, ALT, HoMA-IR, liver stiffness, and APRI (p < 0.001). Subjects with CK18 fragments above the median values showed significantly higher waist circumference, HbA1c, AST, ALT, HoMA-IR, FLI, and APRI compared to those with values below the median; CK18M30 and CK18M65 levels correlated well with anthropometric and metabolic characteristics, representing good biomarkers for early identification of NASH in subjects with visceral obesity.

Diagnostic accuracy of blood biomarkers and non-invasive scores for the diagnosis of NAFLD and NASH: Systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Fatty liver disease is an important public health problem. Early diagnosis is critical to lower its rate of progression to irreversible/terminal stages. This study aimed to evaluate the accuracy of non-invasive prediction scores for fatty liver disease (NAFLD and NASH) diagnosis in adults.

MATERIALS AND METHODS

A search was conducted in 10 databases, a qualitative synthesis of 45 studies, and quantitative analysis of the six most common scores. There were 23 risk scores found for NAFLD diagnosis and 32 for NASH diagnosis. The most used were Fatty Liver Index (FLI), aspartate aminotransferase (AST) to Platelet Ratio Index, Fibrosis-4 Index (FIB-4), AST/alanine aminotransferase (ALT) ratio, BARD score, and NAFLD fibrosis score (NFS).

RESULTS

The results from the meta-analysis for FLI: Area under the curve (AUC) of 0.76 (95% Confidence Interval [CI] 0.73, 0.80), sensitivity 0.67 (CI 95% 0.62, 0.72) and specificity 0.78 (CI 95% 0.74, 0.83). The AST to Platelet Ratio Index: AUC 0.83 (CI 95% 0.80, 0.86), sensitivity 0.45 (95% CI 0.29, 0.62), and specificity of 0.89 (95% CI 0.83, 0.92). The NFS: AUC of 0.82 (CI 95% 0.78, 0.85), sensitivity 0.30 (CI 95% 0.27, 0.33) and specificity 0.96 (CI 95% 0.95,0.96).

CONCLUSIONS

The FLI for NAFLD and AST to Platelet Ratio Index for NASH were the risk scores with the highest prognostic value in the included studies. Further research is needed for the application of new diagnostic risk scores for NAFLD and NASH.

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.

Essential phospholipids decrease apoptosis and increase membrane transport in human hepatocyte cell lines

Background

Essential phospholipids (EPL) have hepatoprotective effects across many liver diseases/conditions. The impact of EPL on hepatocyte function in vitro was investigated.

Methods

Effects of noncytotoxic concentrations of EPL (0.1 and 0.25 mg/ml), and its constituents, polyenylphosphatidylcholine (PPC) and phosphatidylinositol (PI) (both at 0.1 and 1 mg/ml), on membrane fluidity, apoptosis and extracellular transport versus controls were investigated in human hepatocyte cell lines (HepG2, HepaRG, steatotic HepaRG). 

Results

Significantly increased membrane fluidity occurred with all 3 phospholipids (PLs) in HepG2 cultures, and with PI (1 mg/ml) in steatotic HepaRG cells. Significantly decreased tamoxifen-induced apoptosis was observed in HepG2 cells with EPL, PPC and PI. Breast cancer resistance protein (BCRP) activity was significantly increased by EPL and PI in HepG2 cells. Multidrug resistance-associated protein 2 (MRP-2) activity was unaffected by any PL in HepG2 cells, and significantly increased by EPL, PI and PPC (1 mg/ml) in HepaRG cells, and by PI (1 mg/ml) in steatotic HepaRG cells. Bile salt export protein (BSEP) activity in HepG2 cells and steatotic HepaRG cells was significantly increased by EPL (0.25 mg/ml), and PPC (both concentrations), but not by PI. The PLs had no effects on HepaRG cell BSEP activity. P-glycoprotein (P-GP) activity was significantly increased by all compounds in HepG2 cells. PI (1 mg/ml) significantly increased P-GP activity in HepaRG and steatotic HepaRG cells.

Conclusions

EPL, PPC, and PI increased hepatocyte membrane fluidity, decreased apoptosis and increased hepatocellular export, all of which may improve liver function. These in-vitro investigations provide valuable insights into the mechanism of action of EPL.

Advance of Serum Biomarkers and Combined Diagnostic Panels in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) affects approximately 25-30% population worldwide, which progresses from simple steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma, and has complications such as cardiovascular events. Liver biopsy is still the gold standard for the diagnosis of NAFLD, with some limitations, such as invasive, sampling deviation, and empirical judgment. Therefore, it is urgent to develop noninvasive diagnostic biomarkers. Currently, a large number of NAFLD-related serum biomarkers have been identified, including apoptosis, inflammation, fibrosis, adipokines, hepatokines, and omics biomarkers, which could effectively diagnose NASH and exclude patients with progressive fibrosis. We summarized serum biomarkers and combined diagnostic panels of NAFLD, to provide some guidance for the noninvasive diagnosis and further clinical studies.

MAFLD/NAFLD Biopsy-Free Scoring Systems for Hepatic Steatosis, NASH, and Fibrosis Diagnosis

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is the most prevalent liver disorder worldwide. Historically, its diagnosis required biopsy, even though the procedure has a variable degree of error. Therefore, new non-invasive strategies are needed. Consequently, this article presents a thorough review of biopsy-free scoring systems proposed for the diagnosis of MAFLD. Similarly, it compares the severity of the disease, ranging from hepatic steatosis (HS) and nonalcoholic steatohepatitis (NASH) to fibrosis, by contrasting the corresponding serum markers, clinical associations, and performance metrics of these biopsy-free scoring systems. In this regard, defining MAFLD in conjunction with non-invasive tests can accurately identify patients with fatty liver at risk of fibrosis and its complications. Nonetheless, several biopsy-free scoring systems have been assessed only in certain cohorts; thus, further validation studies in different populations are required, with adjustment for variables, such as body mass index (BMI), clinical settings, concomitant diseases, and ethnic backgrounds. Hence, comprehensive studies on the effects of age, morbid obesity, and prevalence of MAFLD and advanced fibrosis in the target population are required. Nevertheless, the current clinical practice is urged to incorporate biopsy-free scoring systems that demonstrate adequate performance metrics for the accurate detection of patients with MAFLD and underlying conditions or those with contraindications of biopsy.

Predictive value of cytokeratin-18 fragment levels for diagnosing steatohepatitis in patients with nonalcoholic fatty liver disease

OBJECTIVE

Several noninvasive markers have been developed to predict nonalcoholic steatohepatitis (NASH). We investigated the predictive value of the cytokeratin-18 fragment (CK18-F) level and FIB-4 index for diagnosing NASH in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

A total of 246 patients histologically diagnosed with NASH (n = 185) or nonalcoholic fatty liver (n = 61) were enrolled. We analyzed weighted receiver operating characteristic (ROC) curves for the prediction of NASH and determined the relationship between the CK18-F level and the histological features of NASH. In addition, we investigated the predictive value of the combination of the CK18-F level and FIB-4 index for diagnosing NASH.

RESULTS

The area under the ROC curve (AUROC) value of the CK18-F level was 0.77. With a CK18-F cutoff level of 260 U/L, the sensitivity and specificity for diagnosing NASH were 82.7 and 57.4%, respectively. Multiple comparisons showed that the CK18-F level did not differ among fibrosis stages but did significantly differ among hepatocyte ballooning grades. Overall, 95.7% (66/69) of patients with a FIB-4 index of ≥2.67 had NASH. In patients with a FIB-4 index of <2.67, the AUROC value of the CK18-F level for predicting NASH was 0.77 and a CK18-F cutoff level of 260 U/L resulted in a sensitivity and specificity of 82.4 and 56.9%.

CONCLUSIONS

The CK18-F level had a good predictive ability for diagnosing NASH in patients with NAFLD. Additionally, the combination of the CK18-F level and FIB-4 index accurately and noninvasively predicted NASH, even those with a low FIB-4 index.

Non-invasive biomarkers in predicting non-alcoholic steatohepatitis and assessing liver fibrosis: systematic review and meta-analysis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is characterized by hepatic steatosis with inflammation, ballooned hepatocytes, and possible fibrosis, which may progress to liver cirrhosis. Although liver biopsy, remains the diagnostic gold standard of NASH, several noninvasive biomarkers have been studied, to avoid the need for this invasive procedure. We performed a systematic review with meta-analysis to evaluate the accuracy of several noninvasive biomarkers in predicting NASH and assessing liver fibrosis in NASH patients.

EVIDENCE ACQUISITION

An electronic search on PubMed and EMBASE was systematically performed. The principal summary outcome was the area under the curve (AUC), assessing the accuracy of NashTest, BARD (body mass index, AST/ALT ratio, diabetes) score, NAFLD fibrosis score (NFS), APRI (aspartate aminotransferase-to-platelet ratio index), and fibrosis-4 (FIB-4) index in predicting NASH and assessing liver fibrosis.

EVIDENCE SYNTHESIS

Thirteen studies involving 6,557 adult patients were included in the qualitative assessment of this review, out of which, six studies were included in the quantitative assessment. Prediction of NASH was evaluated better using NFS (AUC of 0.687) and FIB-4 (AUC of 0.729). Fibrosis stages 0 vs. 1-4 was diagnosed better using NFS (AUC of 0.718) and FIB-4 (AUC of 0.723). Advanced fibrosis was assessed better by BARD (AUC of 0.673), APRI (AUC of 0.762), NFS (AUC of 0.787) and FIB-4 (AUC of 0.821).

CONCLUSIONS

FIB-4 predicted NASH and quantified liver fibrosis, stages 0 vs. 1-4 more precisely compared to NFS, APRI, and BARD. However, considering that methodological quality of the assessed studies is limited, the results should be considered with caution.

The role of noninvasive biomarkers in diagnosis and risk stratification in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronically elevated liver enzymes. Diagnosis and risk stratification of NAFLD remains clinically challenge as patients with NAFLD are either asymptomatic or have nonspecific presenting complaints and may have normal liver enzymes. Nonalcoholic steatohepatitis (NASH), the clinically aggressive variant of NAFLD, is also difficult to differentiate noninvasively, and a liver biopsy is required to definitively diagnose NASH. Thus, the definitive diagnosis and risk stratification of NAFLD is embedded in histological assessment of the liver. Several clinical aides been investigated in an attempt to risk stratify and identify patients noninvasively as doing a liver biopsy in all patients with NAFLD are not feasible. Since these biomarkers are unable to differentiate NASH from non-NASH, they have leveraged biochemical changes within the liver as patients progress to varying degree of hepatic fibrosis to identify patients with moderate fibrosis (fibrosis stage 2 or greater) and advanced fibrosis (fibrosis stage 3 or greater) to help guide the need for additional and more definitive workup. These clinical aides span from by-products of apoptosis to statistical modelling of clinically available data to identify 'at-risk' patients with NAFLD. The current review will focus the diagnostic performance of these noninvasive serum-based biomarkers in NAFLD.

Accuracy of cytokeratin 18 (M30 and M65) in detecting non-alcoholic steatohepatitis and fibrosis: A systematic review and meta-analysis

Introduction

Association between elevated cytokeratin 18 (CK-18) levels and hepatocyte death has made circulating CK-18 a candidate biomarker to differentiate non-alcoholic fatty liver from non-alcoholic steatohepatitis (NASH). Yet studies produced variable diagnostic performance. We aimed to provide summary estimates with increased precision for the accuracy of CK-18 (M30, M65) in detecting NASH and fibrosis among non-alcoholic fatty liver disease (NAFLD) adults.

Methods

We searched five databases to retrieve studies evaluating CK-18 against a liver biopsy in NAFLD adults. Reference screening, data extraction and quality assessment (QUADAS-2) were independently conducted by two authors. Meta-analyses were performed for five groups based on the CK-18 antigens and target conditions, using one of two methods: linear mixed-effects multiple thresholds model or bivariate logit-normal random-effects model.

Results

We included 41 studies, with data on 5,815 participants. A wide range of disease prevalence was observed. No study reported a pre-defined cut-off. Thirty of 41 studies provided sufficient data for inclusion in any of the meta-analyses. Summary AUC [95% CI] were: 0.75 [0.69–0.82] (M30) and 0.82 [0.69–0.91] (M65) for NASH; 0.73 [0.57–0.85] (M30) for fibrotic NASH; 0.68 (M30) for significant (F2-4) fibrosis; and 0.75 (M30) for advanced (F3-4) fibrosis. Thirteen studies used CK-18 as a component of a multimarker model.

Conclusions

For M30 we found lower diagnostic accuracy to detect NASH compared to previous meta-analyses, indicating a limited ability to act as a stand-alone test, with better performance for M65. Additional external validation studies are needed to obtain credible estimates of the diagnostic accuracy of multimarker models.

FICK-3 Score Combining Fibrosis-4, Insulin Resistance and Cytokeratin-18 in Predicting Non-alcoholic Steatohepatitis in NAFLD Egyptian Patients

BACKGROUND AND OBJECTIVE

As liver biopsy had multiple procedure-related complications, the introduction of reliable noninvasive tests for accurate discrimination of NASH and liver fibrosis in patients with NAFLD are mandatory. The aim was to elucidate the diagnostic value of fibrosis-4 index (FIB-4), Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) and Cytokeratin-18 fragments (CK18-Fs) in the prediction of NASH and liver fibrosis.

MATERIALS AND METHODS

One hundred Egyptian patients with NAFLD selected from outpatient's clinics of Mansoura University Hospitals underwent histological examination through liver biopsy after approval and consent. The FIB-4, HOMA-IR, CK18-Fs (measured using a human ELISA Kit) and their combination in FICK-3 score were investigated for predicting NASH and liver fibrosis. Receiver operating characteristic (ROC) curves and multivariate logistic regression were analyzed.

RESULTS

In patients with NAFLD, the areas under the ROC were significantly high (AUC: 0.765, 0.700, 0.803, 0.835 for FIB-4, HOMA-IR, CK18-Fs, FICK-3 score, respectively, p = 0.05) displaying a highly statistically significant predictive ability for NASH. Significantly higher AUCs for these parameters were demonstrated predicting early-or advanced-stage liver fibrosis (AUC >0.7, p<0.01). Also, the combined FICK-3 score (the sum of FIB-4 >1.46, HOMA-IR >2.11 and CK18-Fs >307U L-1) had highly significant predictive values for NASH and liver fibrosis and had the best diagnostic accuracy at a cutoff value of 1(AUC >0.8, p<0.001). Contrasted with other diagnostic scores, FICK-3 had the best diagnostic accuracy for detection of fibrotic NASH (AUC = 0.954, p<0.001) and positively correlated with the histological features of NAFLD.

CONCLUSION

The new combination FICK-3 score was a reliable and significant predictor for NASH and liver fibrosis in NAFLD Egyptian patients.

Noninvasive Evaluation of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver diseases and can progress to advanced fibrosis and end-stage liver disease. Thus, intensive research has been performed to develop noninvasive methods for the diagnosis of nonalcoholic steatohepatitis (NASH) and fibrosis. Currently, no single noninvasive tool covers all of the stages of pathologies and conditions of NAFLD, and the cost and feasibility of known techniques are also important issues. Blood biomarkers for NAFLD may be useful to select subjects who need ultrasonography (US) screening for NAFLD, and noninvasive tools for assessing fibrosis may be helpful to exclude the probability of significant fibrosis and to predict advanced fibrosis, thus guiding the decision of whether to perform liver biopsy in patients with NAFLD. Among various methods, magnetic resonance-based methods have been shown to perform better than other methods in assessing steatosis as well as in detecting hepatic fibrosis. Many genetic markers are associated with the development and progression of NAFLD. Further well-designed studies are needed to determine which biomarker panels, imaging studies, genetic marker panels, or combinations thereof perform well for diagnosing NAFLD, differentiating NASH and fibrosis, and following-up NAFLD, respectively.

Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus: A Position Statement of the Fatty Liver Research Group of the Korean Diabetes Association

This clinical practice position statement, a product of the Fatty Liver Research Group of the Korean Diabetes Association, proposes recommendations for the diagnosis, progression and/or severity assessment, management, and follow-up of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM). Patients with both T2DM and NAFLD have an increased risk of non-alcoholic steatohepatitis (NASH) and fibrosis and a higher risk of cardiovascular diseases and diabetic complications compared to those without NAFLD. With regards to the evaluation of patients with T2DM and NAFLD, ultrasonography-based stepwise approaches using noninvasive biomarker models such as fibrosis-4 or the NAFLD fibrosis score as well as imaging studies such as vibration-controlled transient elastography with controlled attenuation parameter or magnetic resonance imaging-proton density fat fraction are recommended. After the diagnosis of NAFLD, the stage of fibrosis needs to be assessed appropriately. For management, weight reduction achieved by lifestyle modification has proven beneficial and is recommended in combination with antidiabetic agent(s). Evidence that some antidiabetic agents improve NAFLD/NASH with fibrosis in patients with T2DM is emerging. However, there are currently no definite pharmacologic treatments for NAFLD in patients with T2DM. For specific cases, bariatric surgery may be an option if indicated.

Non-invasive diagnosis of non-alcoholic steatohepatitis and advanced fibrosis in Japan: A targeted literature review

Despite the invasive nature of liver biopsy, it remains the current standard for diagnosing non-alcoholic steatohepatitis (NASH) and fibrosis staging. Given the rising prevalence of non-alcoholic fatty liver disease (NAFLD) in Japan, there is a need for reliable non-invasive tests to accurately and efficiently identify NASH and advanced (F3/F4) fibrosis. A review of published works from English and Japanese sources was undertaken in PubMed, Embase, and Ichushi Web to identify studies reporting diagnostic characteristics of NITs in biopsy-proven Japanese NAFLD/NASH patients including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve. The performance of non-invasive tests for two diagnostic questions were assessed, namely: (i) identifying NASH cases among NAFLD; and (ii) distinguishing advanced fibrosis (F3-4) from milder fibrosis (F0-2). Twenty-five studies reported outcomes for serum biomarkers, imaging, scoring systems, and novel complex techniques (based on multivariable regression models) for both diagnostic questions. Serum biomarkers were the most commonly assessed method for NASH identification, whereas scoring systems and imaging techniques were most commonly studied for fibrosis staging. In general, tests for NASH identification showed higher PPVs than NPVs, suggesting their usefulness in identifying probable NASH cases. The reverse was observed for fibrosis staging, with higher NPVs than PPVs, suggesting their use in excluding patients at low risk of F3/F4 disease rather than identifying definite F3/F4 fibrosis. In Japanese studies, simple scoring systems and imaging techniques showed particular usefulness in prediction of fibrosis staging, and combinations of serum biomarkers showed diagnostic potential for NASH screening.

Epidemiology of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in Japan: A focused literature review

Non‐alcoholic fatty liver disease (NAFLD) and non‐alcoholic steatohepatitis (NASH) represent a growing unmet medical need and an increasingly prevalent cause of cirrhosis, hepatocellular carcinoma (HCC), and death in Japan. The aim of this review was to characterize the epidemiology of NAFLD and NASH in Japan. An English and Japanese literature search was conducted in PubMed, Embase, and ICHUSHI Web, identifying 6553 studies, 67 of which were included. Prevalence of NAFLD in the Japanese population rose from the early 1990s (12.6–12.9%) to the early 2000s (24.6–34.7% of the population). Japanese NASH prevalence is estimated to be 1.9–2.7%. NAFLD and NASH are more common among males than females; however, females experience more severe disease than males. While obese patients had higher prevalence of NAFLD/NASH, nonobese individuals (body mass index [BMI] <25 kg/m²) consistently comprised 20% to >35% of NAFLD and NASH patients. The evidence shows that, despite obesity being linked with worse disease stages, “lean‐NASH” also plays an important role in NASH epidemiology. Besides obesity, diabetes and metabolic syndrome appeared to be reliably associated with disease severity. The prevalence of advanced fibrosis or cirrhotic disease was the highest in patients with NASH‐HCC (44–80% with stage F3/F4 disease), while 21–50% of patients with NASH had F3/F4 disease. NAFLD/NASH is common in the Japanese population, and the prevalence of these conditions has tripled in the last two decades. Furthermore, these NAFLD/NASH patients have a high comorbidity burden. Early and efficient identification of safe and effective treatments for NAFLD/NASH patients is urgently needed.

Combined and sequential non-invasive approach to diagnosing non-alcoholic steatohepatitis in patients with non-alcoholic fatty liver disease and persistently normal alanine aminotransferase levels

BACKGROUND AND AIM

Imaging-confirmed non-alcoholic fatty liver disease (NAFLD) with normal alanine aminotransferase (nALT) levels is infrequently the subject for further evaluation. Early diagnosis of non-alcoholic steatohepatitis (NASH) is needed to prevent disease progression. Thus, we tested the clinical utility of serum Golgi protein 73 (GP73) levels and developed a new non-invasive score to diagnose NASH in patients with biopsy-confirmed NAFLD and persistent nALT levels.

METHODS

Serum GP73 and cytokeratin-18 M30 fragments (CK18-M30) levels were measured in 345 patients with biopsy-proven NAFLD. We developed a new score, named G-NASH model (by incorporating serum GP73), and combined it with serum CK18-M30 measurement in a sequential non-invasive approach to accurately identify NASH among patients with NAFLD and persistent nALT levels.

RESULTS

105 (30.4%) patients had persistent nALT, 53 of whom had histologically confirmed NASH. Both serum GP73 and CK18-M30 levels alone had poor diagnostic accuracy in identifying NASH (55.2% and 51.6%, respectively) in these patients. Conversely, G-NASH model performed better than other established non-invasive scoring systems, and by using our proposed sequential non-invasive approach 82.9% of patients with NASH were correctly identified.

CONCLUSIONS

NASH is highly prevalent in patients with NAFLD with persistent nALT levels. The G-NASH model accurately identifies NASH in this patient group.