Clinically Significant Fibrosis Is Associated With Longitudinal Increases in Fibrosis-4 and Nonalcoholic Fatty Liver Disease Fibrosis Scores

An update on the therapeutic role of RNAi in NAFLD/NASH

Unhealthy lifestyles have given rise to a growing epidemic of metabolic liver diseases, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). NAFLD often occurs as a consequence of obesity, and currently, there is no FDA-approved drug for its treatment. However, therapeutic oligonucleotides, such as RNA interference (RNAi), represent a promising class of pharmacotherapy that can target previously untreatable conditions. The potential significance of RNAi in maintaining physiological homeostasis, understanding pathogenesis, and improving metabolic liver diseases, including NAFLD, is discussed in this article. We explore why NAFLD/NASH is an ideal target for therapeutic oligonucleotides and provide insights into the delivery platforms of RNAi and its therapeutic role in addressing NAFLD/NASH.

Development of a Radiomics-Based Model to Predict Graft Fibrosis in Liver Transplant Recipients: A Pilot Study

Liver Transplantation is complicated by recurrent fibrosis in 40% of recipients. We evaluated the ability of clinical and radiomic features to flag patients at risk of developing future graft fibrosis. CT scans of 254 patients at 3-6 months post-liver transplant were retrospectively analyzed. Volumetric radiomic features were extracted from the portal phase using an Artificial Intelligence-based tool (PyRadiomics). The primary endpoint was clinically significant (≥F2) graft fibrosis. A 10-fold cross-validated LASSO model using clinical and radiomic features was developed. In total, 75 patients (29.5%) developed ≥F2 fibrosis by a median of 19 (4.3-121.8) months. The maximum liver attenuation at the venous phase (a radiomic feature reflecting venous perfusion), primary etiology, donor/recipient age, recurrence of disease, brain-dead donor, tacrolimus use at 3 months, and APRI score at 3 months were predictive of ≥F2 fibrosis. The combination of radiomics and the clinical features increased the AUC to 0.811 from 0.793 for the clinical-only model (p = 0.008) and from 0.664 for the radiomics-only model (p < 0.001) to predict future ≥F2 fibrosis. This pilot study exploring the role of radiomics demonstrates that the addition of radiomic features in a clinical model increased the model's performance. Further studies are required to investigate the generalizability of this experimental tool.

Validation of the new 2021 EASL algorithm for the noninvasive diagnosis of advanced fibrosis in NAFLD

BACKGROUND AND AIMS

The European Association for the Study of the Liver (EASL) has recently proposed an algorithm for the diagnosis of advanced liver fibrosis. We aimed to evaluate the diagnostic accuracy of this algorithm in nonalcoholic fatty liver disease (NAFLD).

APPROACH AND RESULTS

One thousand fifty-one patients with NAFLD, liver biopsy, and four noninvasive tests (NITs; Fibrosis-4 [FIB4], vibration controlled transient elastography [VCTE], FibroMeter, Fibrotest) were included. The enhanced liver fibrosis (ELF) score was available in 396 patients. A cohort of 230 patients from primary care/diabetes clinics had FIB4, VCTE, and ELF. Compared with the performance of single NITs, agreement between two NITs (FIB4 and VCTE, VCTE and patented serum tests) increased specificity and positive predictive value by 20%, thus justifying the sequential use proposed in the EASL algorithm. The FIB4/VCTE/FibroMeter and FIB4/VCTE/Fibrotest algorithms performed similarly, providing 85% diagnostic accuracy and a liver biopsy requirement rate of only 10%. The FIB4/VCTE/ELF algorithm performed similarly in the subgroup where ELF was available. Simulations of algorithm accuracies at different prevalence showed that positive predictive values rapidly increased, reaching a plateau above 75% starting at 15% prevalence. Negative predictive values remained higher than 90% up to 25% prevalence. The rate of liver biopsy requirement remained stable, increasing by only 5% between low and high prevalence settings. When the EASL algorithm was applied in the primary care/diabetes clinic cohort, liver biopsy requirement was only 3%, and the agreement among the three steps provided 75% positive predictive value.

CONCLUSIONS

Our study validates the algorithm proposed by the EASL in its latest 2021 guidelines for the diagnosis of advanced fibrosis in the setting of NAFLD.

Predicting Liver-Related Outcomes in People With Nonalcoholic Fatty Liver Disease: The Prognostic Value of Noninvasive Fibrosis Tests

It remains unclear whether screening for advanced fibrosis in the community can identify the subgroup of people with nonalcoholic fatty liver disease (NAFLD) at higher risk for development of liver‐related complications. We aimed to determine the prognostic value of baseline noninvasive fibrosis tests for predicting liver‐related outcomes and mortality in patients with NAFLD from type 2 diabetes (T2D) clinics or primary care. Patients (n = 243) who were screened for NAFLD with advanced fibrosis by using NAFLD fibrosis score (NFS), fibrosis 4 score (FIB‐4), enhanced liver fibrosis (ELF) test, and liver stiffness measurements (LSMs) were followed up for clinical outcomes by review of electronic medical records. During a median follow‐up of 50 months, decompensated liver disease or primary liver cancer occurred in 6 of 35 (17.1%) patients with baseline LSM > 13 kPa, 1 of 17 (5.9%) patients with LSM 9.5‐13 kPa, and in no patients with LSM < 9.5 kPa. No patient with low‐risk NFS developed liver decompensation or liver‐related mortality. Following repeat NFSs at the end of follow‐up, all patients with a liver‐related complication were in the high‐risk NFS category. Patients who developed liver‐related complications were also more likely to have baseline high‐risk FIB‐4 scores or ELF test ≥9.8 compared to patients who did not develop liver outcomes. Conclusion: Liver fibrosis risk stratification in non‐hepatology settings can identify the subset of patients at risk of liver‐related complications. Although the rate of development of a decompensation event or hepatocellular carcinoma was low (2.1% per year) in our patients with compensated cirrhosis (LSM > 13 kPa), these events are projected to lead to a substantial increase in NAFLD‐related disease burden over the next decade due to the high prevalence of NAFLD in people with obesity and T2D.

Non-alcoholic fatty liver disease in diabetes: When to refer to the hepatologist?

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases worldwide. A strong relationship exists between NAFLD and diabetes mellitus. There is growing evidence of a mechanistically complex and strong association between the two diseases. Current data also shows that one disease actually leads to worsening of the other and vice versa. Understanding of the various pathophysiological mechanisms involved, natural history and spectrum of these two diseases is essential not only for early diagnosis and management but also for prevention of severe disease forms. Despite the tremendous progress made in recent times in acquiring knowledge about these highly prevalent diseases, the guidelines and recommendations for screening and management of diabetics with NAFLD remain ambiguous. An interdisciplinary approach is required to not only raise awareness of the prevalence of NAFLD in diabetics but also for better patient management. This can help attenuate the development of significant complications, such as cirrhosis, decompensation and hepatocellular carcinoma in these patients, thereby halting NAFLD in its tracks. This review focuses on the pivotal role of primary care physicians and endocrinologists in identification of NAFLD in diabetics in early stages and the role of proactive screening for prompt referral to hepatologist.

Decline in serum albumin concentration is a predictor of serious events in nonalcoholic fatty liver disease

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD) is associated with metabolic syndrome, which includes diabetes mellitus and hyperlipidemia. A fraction of NAFLD patients develop nonalcoholic steatohepatitis, leading to cirrhosis associated with various serious complications, including hepatocellular carcinoma, gastroesophageal varices, cardiovascular events, and other organ malignancy. Although the incidence of chronic viral hepatitis with associated complications has gradually decreased as highly effective antiviral therapies have been established, the number of patients with steatohepatitis has been increasing.This retrospective study examined data of 229 patients from 22 hospitals in our region. We examined 155 cases of chronological data and assessed the development of liver fibrosis and evaluated hepatic reserve-related markers such as platelet count, FIB-4 index, prothrombin time, and serum albumin concentration. We analyzed the relationship of these chronological changes and the incidence of NAFLD related serious complications.Data related to liver fibrosis progression, albumin, and prothrombin time were significantly associated with the occurrence of serious complications associated with cirrhosis. We compared 22 event and 133 nonevent cases of chronological changes in the data per year and found that serum albumin concentration was significantly lower in the group that developed serious complications (event cases: -0.21 g/dL/year, nonevent cases: -0.04 g/dL/year (P < .001)). This albumin decline was only the associated factor with the event incidence by multivariate analysis (P < .01).Annual decline in serum albumin concentration in patients with NAFLD is associated with serious events from the outcome of multicenter retrospective study. This highlights its potential utility as a surrogate marker to assess the efficacy of prediction of NAFLD related serious events.

Green Tea and Epigallocatechin Gallate (EGCG) for the Management of Nonalcoholic Fatty Liver Diseases (NAFLD): Insights into the Role of Oxidative Stress and Antioxidant Mechanism

Nonalcoholic fatty liver diseases (NAFLD) represent a set of liver disorders progressing from steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma, which induce huge burden to human health. Many pathophysiological factors are considered to influence NAFLD in a parallel pattern, involving insulin resistance, oxidative stress, lipotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, inflammatory cascades, fibrogenic reaction, etc. However, the underlying mechanisms, including those that induce NAFLD development, have not been fully understood. Specifically, oxidative stress, mainly mediated by excessive accumulation of reactive oxygen species, has participated in the multiple NAFLD-related signaling by serving as an accelerator. Ameliorating oxidative stress and maintaining redox homeostasis may be a promising approach for the management of NAFLD. Green tea is one of the most important dietary resources of natural antioxidants, above which epigallocatechin gallate (EGCG) notably contributes to its antioxidative action. Accumulative evidence from randomized clinical trials, systematic reviews, and meta-analysis has revealed the beneficial functions of green tea and EGCG in preventing and managing NAFLD, with acceptable safety in the patients. Abundant animal and cellular studies have demonstrated that green tea and EGCG may protect against NAFLD initiation and development by alleviating oxidative stress and the related metabolism dysfunction, inflammation, fibrosis, and tumorigenesis. The targeted signaling pathways may include, but are not limited to, NRF2, AMPK, SIRT1, NF-κB, TLR4/MYD88, TGF-β/SMAD, and PI3K/Akt/FoxO1, etc. In this review, we thoroughly discuss the oxidative stress-related mechanisms involved in NAFLD development, as well as summarize the protective effects and underlying mechanisms of green tea and EGCG against NAFLD.

Whole-liver histogram and texture analysis on T1 maps improves the risk stratification of advanced fibrosis in NAFLD

Objectives

To assess whole-liver texture analysis on T1 maps for risk stratification of advanced fibrosis in patients with suspected nonalcoholic fatty liver disease (NAFLD).

Methods

This retrospective study included 53 patients. Histogram and texture parameters (volume, mean, SD, median, 5th percentile, 95th percentile, skewness, kurtosis, diff-entropy, diff-variance, contrast, and entropy) of T1 maps were calculated based on the semi-automatically segmented whole-liver volume. A two-step approach combining the Nonalcoholic Fatty Liver Disease Fibrosis Score (NFS) and Fibrosis-4 Index (FIB-4) with the liver stiffness measurement (LSM) for the risk stratification was used. Univariate analysis was performed to identify significant parameters. Logistic regression models were then run on the significant features. Diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis.

Results

In total, 33 (62%) subjects had a low risk and 20 (38%) subjects had an intermediate-to-high risk of advanced fibrosis. The following significantly different parameters with the best performance were diff-entropy, entropy, and diff-variance, with AUROC 0.837 (95% CI 0.73–0.95), 0.821 (95% CI 0.71–0.94), and 0.807 (95% CI 0.69–0.93). The optimal combination of median, 5th percentile, and diff-entropy as a multivariate model improved the diagnostic performance to diagnose an intermediate-to-high risk of advanced fibrosis with AUROC 0.902(95% CI 0.79–0.97).

Conclusions

Parameters obtained by histogram and texture analysis of T1 maps may be a noninvasive analytical approach for stratifying the risk of advanced fibrosis in NAFLD.

Key Points

• Variable flip angle (VFA) T1 mapping can be used to acquire 3D T1 maps within a clinically acceptable duration.

• Whole-liver histogram and texture parameters on T1 maps in patients with NAFLD can distinguish those with an intermediate-to-high risk of advanced fibrosis.

• The multivariate model of combination of texture parameters improved the diagnostic performance for a high risk of advanced fibrosis and clinical parameters offer no added value to the multivariate model.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07235-4) contains supplementary material, which is available to authorized users.

The Intricate Relationship between Type 2 Diabetes Mellitus (T2DM), Insulin Resistance (IR), and Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) remain as one of the most global problematic metabolic diseases with rapidly increasing prevalence and incidence. Epidemiological studies noted that T2DM patients have by two-fold increase to develop NAFLD, and vice versa. This complex and intricate association is supported and mediated by insulin resistance (IR). In this review, we discuss the NAFLD immunopathogenesis, connection with IR and T2DM, the role of screening and noninvasive tools, and mostly the impact of the current antidiabetic drugs on steatosis liver and new potential therapeutic targets.