Risk factors for histological progression of non-alcoholic steatohepatitis analyzed from repeated biopsy cases

Sodium-glucose cotransporter-2 inhibitors improve FibroScan-aspartate aminotransferase scores in patients with nonalcoholic fatty liver disease complicated by type 2 diabetes

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease caused by excessive lipid accumulation in the liver, and its global incidence is increasing. Sodium-glucose cotransporter-2 inhibitors (SGLT2is) are oral antidiabetes drugs that promote glucose excretion into the urine and have been reported to exert therapeutic effects in NAFLD, but liver stiffness measurements (LSMs) determined by transient elastography are inconsistent. In addition, the effects of SGLT2is on the FibroScan-aspartate aminotransferase (FAST) scores have not been reported. We evaluated the effect of SGLT2is on patients with NAFLD complicated by type 2 diabetes using biochemical tests, transient elastography, and FAST scores.

METHODS

Fifty-two patients with type 2 diabetes complicated by NAFLD who started SGLT2i treatment between 2014 and 2020 at our hospital were selected from the database. Pre- and post-treatment serum parameters, transient elastography, and FAST scores were compared.

RESULTS

After 48 weeks of SGLT2i treatment, body weight, fasting blood glucose, hemoglobin A1c, AST, alanine aminotransferase, gamma-glutamyltransferase, uric acid, fibrosis-4 index, and AST to platelet ratio index improved. Median LSM decreased from 7.0 kPa to 6.2 kPa ( P  = 0.023) and the median controlled attenuation parameter decreased from 304 dB/m to 283 dB/m ( P  = 0.022). Median FAST score decreased from 0.40 to 0.22 ( P  < 0.001), and the number of cases with a cutoff value of ≥0.35 decreased from 15 to 6 ( P  = 0.001).

CONCLUSION

SGLT2i use not only improves weight loss and blood glucose levels but also improves hepatic fibrosis by ameliorating hepatic steatosis and inflammation.

Update on Non-Alcoholic Fatty Liver Disease-Associated Single Nucleotide Polymorphisms and Their Involvement in Liver Steatosis, Inflammation, and Fibrosis: A Narrative Review

Genetic factors are involved in the development, progression, and severity of NAFLD. Polymorphisms in genes regulating liver functions may increase liver susceptibility to NAFLD. Therefore, we conducted this literature study to present recent findings on NAFLD-associated polymorphisms from published articles in PubMed from 2016 to 2021. From 69 selected research articles, 20 genes and 34 SNPs were reported to be associated with NAFLD. These mutated genes affect NAFLD by promoting liver steatosis (PNPLA3, MBOAT7, TM2SF6, PTPRD, FNDC5, IL-1B, PPARGC1A, UCP2, TCF7L2, SAMM50, IL-6, AGTR1, and NNMT), inflammation (PNPLA3, TNF-α, AGTR1, IL-17A, IL-1B, PTPRD, and GATAD2A), and fibrosis (IL-1B, PNPLA3, MBOAT7, TCF7L2, GATAD2A, IL-6, NNMT, UCP, AGTR1, and TM2SF6). The identification of these genetic factors helps to better understand the pathogenesis pathways of NAFLD

Molecular signatures of long-term hepatocellular carcinoma risk in nonalcoholic fatty liver disease

Prediction of hepatocellular carcinoma (HCC) risk is an urgent unmet need in patients with nonalcoholic fatty liver disease (NAFLD). In cohorts of 409 patients with NAFLD from multiple global regions, we defined and validated hepatic transcriptome and serum secretome signatures predictive of long-term HCC risk in patients with NAFLD. A 133-gene signature, prognostic liver signature (PLS)-NAFLD, predicted incident HCC over up to 15 years of longitudinal observation. High-risk PLS-NAFLD was associated with IDO1+ dendritic cells and dysfunctional CD8+ T cells in fibrotic portal tracts along with impaired metabolic regulators. PLS-NAFLD was validated in independent cohorts of patients with NAFLD who were HCC naïve (HCC incidence rates at 15 years were 22.7 and 0% in high- and low-risk patients, respectively) or HCC experienced (de novo HCC recurrence rates at 5 years were 71.8 and 42.9% in high- and low-risk patients, respectively). PLS-NAFLD was bioinformatically translated into a four-protein secretome signature, PLSec-NAFLD, which was validated in an independent cohort of HCC-naïve patients with NAFLD and cirrhosis (HCC incidence rates at 15 years were 37.6 and 0% in high- and low-risk patients, respectively). Combination of PLSec-NAFLD with our previously defined etiology-agnostic PLSec-AFP yielded improved HCC risk stratification. PLS-NAFLD was modified by bariatric surgery, lipophilic statin, and IDO1 inhibitor, suggesting that the signature can be used for drug discovery and as a surrogate end point in HCC chemoprevention clinical trials. Collectively, PLS/PLSec-NAFLD may enable NAFLD-specific HCC risk prediction and facilitate clinical translation of NAFLD-directed HCC chemoprevention.

Molecular Signature Predictive of Long-Term Liver Fibrosis Progression to Inform Antifibrotic Drug Development

BACKGROUND & AIMS

There is a major unmet need to assess the prognostic impact of antifibrotics in clinical trials because of the slow rate of liver fibrosis progression. We aimed to develop a surrogate biomarker to predict future fibrosis progression.

METHODS

A fibrosis progression signature (FPS) was defined to predict fibrosis progression within 5 years in patients with hepatitis C virus and nonalcoholic fatty liver disease (NAFLD) with no to minimal fibrosis at baseline (n = 421) and was validated in an independent NAFLD cohort (n = 78). The FPS was used to assess response to 13 candidate antifibrotics in organotypic ex vivo cultures of clinical fibrotic liver tissues (n = 78) and cenicriviroc in patients with nonalcoholic steatohepatitis enrolled in a clinical trial (n = 19, NCT02217475). A serum protein-based surrogate FPS was developed and tested in a cohort of compensated cirrhosis patients (n = 122).

RESULTS

A 20-gene FPS was defined and validated in an independent NAFLD cohort (adjusted odds ratio, 10.93; area under the receiver operating characteristic curve, 0.86). Among computationally inferred fibrosis-driving FPS genes, BCL2 was confirmed as a potential pharmacologic target using clinical liver tissues. Systematic ex vivo evaluation of 13 candidate antifibrotics identified rational combination therapies based on epigallocatechin gallate, which were validated for enhanced antifibrotic effect in ex vivo culture of clinical liver tissues. In patients with nonalcoholic steatohepatitis treated with cenicriviroc, FPS modulation was associated with 1-year fibrosis improvement accompanied by suppression of the E2F pathway. Induction of the PPARα pathway was absent in patients without fibrosis improvement, suggesting a benefit of combining PPARα agonism to improve the antifibrotic efficacy of cenicriviroc. A 7-protein serum protein-based surrogate FPS was associated with the development of decompensation in cirrhosis patients.

CONCLUSION

The FPS predicts long-term fibrosis progression in an etiology-agnostic manner, which can inform antifibrotic drug development.

Underestimation of impaired glucose tolerance and usefulness of a continuous glucose monitoring system in chronic liver disease

BACKGROUND AND AIM

The prevalence of glucose intolerance in chronic liver disease patients is high, but glucose intolerance may be overlooked in a single blood test. The purpose of this study is to evaluate blood glucose variability in patients with chronic liver disease by a continuous glucose monitoring system (CGMS) and to examine the discrepancy between hemoglobin A1c (HbA1c) levels estimated from average blood glucose levels and HbA1c.

METHODS

This study included 335 patients with chronic liver disease associated with glucose intolerance. A fasting blood test and 72-h CGMS were performed. The estimated HbA1c was calculated from the average blood glucose level, and the correlation between hepatic functional reserve and blood glucose-related parameters was analyzed. From the obtained data, we created a new formula to calculate HbA1c without using CGMS.

RESULTS

As hepatic functional reserve decreased, average blood glucose and insulin resistance increased while HbA1c decreased (P < 0.0001). The discrepancy between the estimated HbA1c calculated from the mean blood glucose level and the serum HbA1c (ΔHbA1c) increased as the liver reserve decreased. Using multiple regression analysis, a formula based on fasting blood glucose, HbA1c, body mass index, albumin, and liver function was constructed, and its validity was demonstrated in a study using a different control group.

CONCLUSIONS

Hemoglobin A1c may be underestimated because of decreased hepatic functional reserve. CGMS was useful in assessing accurate glycemic control of blood glucose and in detecting postprandial hyperglycemia and nocturnal hypoglycemia. Patients with chronic hepatic impairment should be corrected for hepatic functional reserve before glycemic control.

TNF-α signaling in non-alcoholic steatohepatitis and targeted therapies

Nonalcoholic steatohepatitis (NASH), an inflammatory subtype of nonalcoholic fatty liver disease (NAFLD), is featured by significantly elevated levels of various pro-inflammatory cytokines. Among numerous pro-inflammatory factors that contribute to NASH pathogenesis, the secreted protein, tumor necrosis factor-alpha (TNF-α) plays an essential role in multiple facets of NASH progression and is therefore considered as a potential therapeutic target. In this review, we will first systematically describe the preclinical studies on the biochemical function of TNF-α and its intracellular downstream signaling mechanisms through its receptors. Moreover, we extensively discuss its functions in regulating inflammation, cell death, and fibrosis of liver cells in the pathogenesis of NASH, and the molecular mechanism that TNF-α expression was regulated by NF-κB and other upstream master regulators during NASH progression. As TNF-α is one of the causal factors that remarkably contributes to NASH progression, combination of therapeutic modalities, including TNF-α-based therapies may lead to resolution of NASH via multiple pathways and thus generate clinical benefits. For translational studies, we summarize recent advances in strategies targeting TNF-α and its signaling pathway, which paves the way for potential therapeutic treatments for NASH in future.

The Relationship between Metabolic Syndrome and Plasma Metals Modified by EGFR and TNF-α Gene Polymorphisms

With the escalating global prevalence of metabolic syndrome (MetS), it is crucial to detect the high-risk population early and to prevent chronic diseases. Exposure to various metals has been indicated to promote MetS, but the findings were controversial, and the effect of genetic modification was not considered. Epidermal growth factor receptor (EGFR) was proposed to be involved in the pathway of metabolic disorders, and tumor necrotic factor-α (TNF-α) was regarded as an early inflammatory biomarker for MetS. This research aimed to analyze the impact of EGFR and TNF-α gene polymorphisms on the prevalence of MetS under environmental or occupational exposure to metals. We gathered data from 376 metal industrial workers and 639 non-metal workers, including physical parameters, biochemical data, and plasma concentrations of six metals. According to the genomic database of Taiwan Biobank, 23 single nucleotide polymorphisms (SNPs) on EGFR gene and 6 SNPs on TNF-α gene were incorporated in our research. We applied multivariable logistic regression to analyze the probability of MetS with various SNPs and metals. Our study revealed some susceptible and protective EGFR and TNF-α genotypes under excessive exposure to cobalt, zinc, selenium, and lead. Thus, we remind the high-risk population of taking measures to prevent MetS.

Therapeutic effects of sleeve gastrectomy for non-alcoholic steatohepatitis estimated by paired liver biopsy in morbidly obese Japanese patients

Bariatric surgery has been reported to improve non-alcoholic steatohepatitis (NASH), which is a frequent comorbidity in morbidly obese patients. We performed a retrospective cohort study to estimate the therapeutic effect of sleeve gastrectomy (SG), the most common bariatric surgery in Japan, on obese patients with NASH by comparing the findings of paired liver biopsies.Eleven patients who underwent laparoscopic SG for the treatment of morbid obesity, defined as body mass index (BMI) > 35 kg/m2, from March 2015 to June 2019 at Hiroshima University Hospital, Japan, were enrolled. All patients were diagnosed with NASH by liver biopsy before or during SG and were re-examined with a second liver biopsy 1 year after SG. The clinical and histological characteristics were retrospectively analyzed.One year after SG, body weight and BMI were significantly reduced, with median reductions in body weight and BMI of-22 kg and -7.9 kg/m2, respectively. Body fat was also significantly reduced at a median of 13.7%. Liver-related enzymes were also significantly improved. On re-examination by paired liver biopsy, liver steatosis improved in 9 of the 11 patients (81.8%), ruling out of the pathological diagnosis of NASH. However, fibrosis stage did not significantly improve 1 year after SG. The non-alcoholic fatty liver disease activity score was significantly reduced in 10 of 11 patients (90.9%).Pathological improvement or remission of NASH could be achieved in most morbidly obese Japanese patients 1 year after SG.

Controversies and Opportunities in the Use of Inflammatory Markers for Diagnosis or Risk Prediction in Fatty Liver Disease

In the Western society, non-alcoholic fatty liver disease (NAFLD), characterized by the excessive accumulation of fat in the liver, represents the most common cause of chronic liver disease. If left untreated, approximately 15%-20% of patients with NAFLD will progress to non-alcoholic steatohepatitis (NASH), in which lobular inflammation, hepatocyte ballooning and fibrogenesis further contribute to a distorted liver architecture and function. NASH initiation has significant effects on liver-related mortality, as even the presence of early stage fibrosis increases the chances of adverse patient outcome. Therefore, adequate diagnostic tools for NASH are needed, to ensure that relevant therapeutic actions can be taken as soon as necessary. To date, the diagnostic gold standard remains the invasive liver biopsy, which is associated with several drawbacks such as high financial costs, procedural risks, and inter/intra-observer variability in histology analysis. As liver inflammation is a major hallmark of disease progression, inflammation-related circulating markers may represent an interesting source of non-invasive biomarkers for NAFLD/NASH. Examples for such markers include cytokines, chemokines or shed receptors from immune cells, circulating exosomes related to inflammation, and changing proportions of peripheral blood mononuclear cell (PBMC) subtypes. This review aims at documenting and critically discussing the utility of such novel inflammatory markers for NAFLD/NASH-diagnosis, patient stratification and risk prediction.

Elevated Glycated Hemoglobin Is Associated With Liver Fibrosis, as Assessed by Elastography, in a Population-Based Study of Mexican Americans

Diabetes is associated with liver disease and risk of hepatocellular carcinoma. In this study, we evaluated the association between liver fibrosis measured by transient elastography and four glucose metabolism measures in the Cameron County Hispanic Cohort, a population-based, randomly selected cohort of Mexican American Hispanics with high rates of diabetes and liver cancer. We measured liver fibrosis (a risk factor for hepatocellular carcinoma) in 774 well-characterized cohort participants using transient elastography. We evaluated the association of liver fibrosis with glycated hemoglobin (HbA1c), fasting blood glucose, insulin, and insulin resistance using multivariable linear regression models. In multivariable models, log-transformed HbA1c had the strongest association with liver fibrosis (β = 0.37, 95% confidence interval [CI] 0.04-0.69, P = 0.038), after controlling for waist circumference, aspartate aminotransferase, alanine aminotransferase, liver fat, and other known confounders. The association was statistically significant among women (β = 0.33, 95% CI 0.10-0.56, P = 0.009) and similar but nonsignificant among men (β = 0.41, 95% CI -0.17 to 0.98, P = 0.593). Waist circumference, platelet count, aspartate transaminase, and liver steatosis were each associated with liver stiffness. Conclusions: Elevated HbA1c is associated with liver fibrosis, a key risk factor for HCC, particularly among women. Our results indicate that Mexican Americans with uncontrolled HbA1c may benefit from routine screening by liver elastography to identify individuals at risk of liver disease progression.