Predictors of fibrosis in Asian patients with non-alcoholic steatohepatitis

Background and Aim: Non‐alcoholic steatohepatitis (NASH) is increasingly recognized as an important cause of chronic liver disease. However, data on Asians with NASH is lacking in the literature. The aim of the present study was to describe the clinical, biochemical and histological characteristics of NASH in Asians and to determine the predictors for septal fibrosis. Method: Sixty consecutive patients aged over 18 years with elevated serum alanine transferase, sonographic evidence of steatosis, and consent for liver biopsy were included. Patients with chronic hepatitis B or C, alcoholic, autoimmune, genetic, or drug‐induced liver disease were excluded. Clinical, biochemical and histological variables were tested for association with septal liver fibrosis (F2/3). Results: Median age of the cohort was 45.5 years (range 21–75 years) and 63% were male. Ninety percent of patients were obese (body mass index [BMI]≥ 25), 70% had hypertriglyceridemia, 68% had hypercholesterolemia, 58% had metabolic syndrome, 53% had hypertension, 47% had diabetes mellitus (DM), and 18% had obstructive sleep apnea. Sixty‐eight percent had gamma‐glutamyl transferase (GGT) ≥ 2 × upper limit of normal (ULN), 55% had alanine aminotransferase (ALT) ≥ 2 × ULN, and 23% had aspartate aminotransferase (AST) ≥ 2 × ULN. Of the 40 non‐diabetic patients undergoing oral glucose tolerance testing, 45% had normal tests, 30% had impaired glucose tolerance, 23% DM, and 2% impaired fasting glucose. Eighteen patients (30%) had septal fibrosis (F2/3), but none had cirrhosis. Necroinflammatory grade ≥ 2 (odds ratio [OR] 13), AST ≥ 2 × ULN (OR 5.3) and DM (OR 5) were significantly and independently correlated with septal fibrosis. Conclusion: Septal fibrosis is common in Asians with NASH. Necroinflammatory grade ≥ 2, AST ≥ 2 × ULN and DM are independent predictors for septal fibrosis.     

Commonly used animal models of non-alcoholic steatohepatitis

BACKGROUND:Animal models are an essential tool in non-alcoholic steatohepatitis (NASH) studies. Ideally, such models should reflect the etiology, disease progression, and the established pathology of human NASH. To date, no single animal model displays the range of histopathologic and pathophysiologic features associated with human NASH. The currently available models do not or only partially reflect the real picture of human NASH. In particular, insulin resistance and fibrosing steatohepatitis are rarely r...     

Effects of estrogen and androgen deprivation on the progression of non-alcoholic steatohepatitis (NASH) in male Sprague–Dawley rats

Aim:  We studied the mechanisms of estrogen/androgen involvement in the induction of NASH by treating Sprague–Dawley (SD) rats fed with a normal or high fat (HF) diet by depriving them of endogenous estrogens/androgens.
Methods:  Male adult SD rats ( n  = 10/group) on normal or HF diets were treated for 75 days either with tamoxifen (Tam) or flutamide (Flu) or Tam + Flu in order to induce NASH. We analyzed histopathologically the liver samples from the treated groups for NASH, checked the serum biochemical and lipid profile markers and finally analyzed the signal pathways underlying the molecular mechanisms for the induction process of NASH.
Results:  Deprivation of endogenous estrogens and/or androgens (Tam or Flu or Tam + Flu) without the HF diet did not induce NASH. Tam or Tam + Flu induced NASH, compared to milder lesions without fibrosis in HF diet and Flu-treated liver. Serum alanine aminotransferase or lipid profile markers further proved the Tam, Flu or Tam + Flu effects on the induction of NASH in conjunction with a HF diet. Tam treatment predominantly downregulated the ERα and FAS and upregulated UCP2 and TNF-α.
Conclusions:  Deprivation of endogenous estrogen/androgens in conjunction with a HF diet may induce NASH where the downregulated ERα and FAS, and upregulated UCP2 and TNF-α could be involved in their molecular pathomechanism pathways. These results could suggest the potential negative roles of estrogenic/androgenic depriving compounds in the induction of NASH, along with obesity.     

Influence of age and gender in Japanese patients with non-alcoholic steatohepatitis

Aim: Nonalcoholic steatohepatitis (NASH) is considered to be a manifestation of metabolic syndrome. Because prevalence and severity of metabolic syndrome are different according to ages, gender and ethnic group, it is speculated that the clinicopathological features of NASH may also vary in relation to these factors. The present study was performed to clarify the influence of age and gender on the development of Japanese NASH. Subjects: One hundred 93 biopsy-proven NASH patients (86 women and 107 men) were included in this cross-sectional study. The patients were separately analyzed by generation; a younger group (<55 years old) and an older group (>/=55 years old). These groups were compared for their clinical and histological features. Independent risk factors for advanced fibrosis were also analyzed. Results: Comparison of our younger and older groups showed that older patients had much more advanced fibrosis than the younger ones (advanced fibrosis: 23.8%; youngergroup vs. 54.3%; older group, P < 0.001). Women were predominant in the older group (23.8%; younger group vs. 67.4%; older group, P < 0.001). According to the multivariate analysis for risk factors for advanced fibrosis, age (P = 0.007) and BMI (P = 0.028) were independent predictors of advanced fibrosis in the younger group. In contrast, the absence of hyperlipidemia (P = 0.042) was the only significant independent predictor of advanced fibrosis in the older group. Gender was not a risk factor for the severity of NASH. Conclusions: Clinicians need to be aware of age- and gender-specific differences when assessing the characteristics of NASH, and the findings may be useful for prevention and treatment of this disease.     

Sampling variability of liver biopsy in nonalcoholic fatty liver disease

BACKGROUND & AIMS: In nonalcoholic fatty liver disease (NAFLD), the distinction between steatosis and steatohepatitis (NASH) and the assessment of the severity of the disease rely on liver histology alone. The aim of this study was to assess the sampling error of liver biopsy and its impact on the diagnosis and staging of NASH. METHODS: Fifty-one patients with NAFLD underwent percutaneous liver biopsy with 2 samples collected. The agreement between paired biopsy specimens was assessed by the percentage of discordant results and by the kappa reliability test. RESULTS: No features displayed high agreement; substantial agreement was only seen for steatosis grade; moderate agreement for hepatocyte ballooning and perisinusoidal fibrosis; fair agreement for Mallory bodies; acidophilic bodies and lobular inflammation displayed only slight agreement. Overall, the discordance rate for the presence of hepatocyte ballooning was 18%, and ballooning would have been missed in 24% of patients had only 1 biopsy been performed. The negative predictive value of a single biopsy for the diagnosis of NASH was at best 0.74. Discordance of 1 stage or more was 41%. Six of 17 patients with bridging fibrosis (35%) on 1 sample had only mild or no fibrosis on the other and therefore could have been under staged with only 1 biopsy. Intraobserver variability was systematically lower than sampling variability and therefore could not account for most of the sampling error. CONCLUSIONS: Histologic lesions of NASH are unevenly distributed throughout the liver parenchyma; therefore, sampling error of liver biopsy can result in substantial misdiagnosis and staging inaccuracies.     

Roles of adipose restriction and metabolic factors in progression of steatosis to steatohepatitis in obese, diabetic mice

Background and Aims: We previously reported that steatohepatitis develops in obese, hypercholesterolemic, diabetic foz/foz mice fed a high‐fat (HF) diet for 12 months. We now report earlier onset of steatohepatitis in relation to metabolic abnormalities, and clarify the roles of dietary fat and bodily lipid partitioning on steatosis severity, liver injury and inflammatory recruitment in this novel non‐alcoholic steatohepatitis (NASH) model. Methods: Foz/foz (Alms1 mutant) and wild‐type (WT) mice were fed a HF diet or chow, and metabolic characteristics and liver histology were studied at 2, 6, 12 and 24 weeks. Results: After 12 weeks HF‐feeding, foz/foz mice were obese and diabetic with approximately 70% reduction in serum adiponectin. Hepatomegaly developed at this time, corresponding to a plateau in adipose expansion and increased adipose inflammation. Liver histology showed mild inflammation and hepatocyte ballooning as well as steatosis. By 24 weeks, HF‐fed foz/foz mice developed severe steatohepatitis (marked steatosis, alanine aminotransferase elevation, ballooning, inflammation, fibrosis), whereas dietary and genetic controls showed only simple steatosis. While steatosis was associated with hepatic lipogenesis, indicated by increased fatty acid synthase activity, steatohepatitis was associated with significantly higher levels of CD36, indicating active fatty acid uptake, possibly under the influence of peroxisome proliferator‐activated receptor‐γ. Conclusion: In mice genetically predisposed to obesity and diabetes, HF feeding leads to restriction of adipose tissue for accommodation of excess energy, causing lipid partitioning into liver, and transformation of simple steatosis to fibrosing steatohepatitis. The way in which HF feeding ‘saturates’ adipose stores, decreases serum adiponectin and causes hepatic inflammation in steatohepatitis may provide clues to pathogenesis of NASH in metabolic syndrome.     

Role of hepatic iron in non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) includes a spectrum of clinical entities ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) with possible evolution to cirrhosis and hepatocellular carcinoma. Iron is considered a putative element that interacts with oxygen radicals in inducing liver damage and fibrosis. The role of hepatic iron in the progression of NASH remains controversial, but in some patients, iron may have a role in the pathogenesis of NASH. Though genetic factors, insulin resistance, dysregulation of iron-regulatory molecules, erythrophagocytosis by Kupffer cells may be responsible for hepatic iron accumulation in NASH, exact mechanisms involved in iron overload remain to be clarified. Iron reduction therapy such as phlebotomy or dietary iron restriction may be promising in patients with NASH/NAFLD to reduce insulin resistance as well as serum transaminase activities.     

Current management of non‐alcoholic steatohepatitis

Non‐alcoholic steatohepatitis (NASH) is the most common cause of liver disease in Western populations, and its prevalence is increasing rapidly. It is part of a multisystem disease affecting other organs such as the kidneys, heart and blood vessels, and is closely associated with the components of the metabolic syndrome. Physicians managing patients with NASH should not only focus on the management of NASH, but also on associated comorbidities in individual patients. The approaches to treatment of NASH include either limiting energy surplus alone, or in combination with targeting of downstream pathways of inflammation and fibrosis. In this mini‐review, we discuss the currently available treatment options for NASH, as well as those in late‐stage clinical trials. We discuss the challenges of managing these patients with a limited number of approved therapies, as well as managing advanced‐stage patients with NASH and cirrhosis. We also discuss the specific management of comorbidities in NASH patients, in particular diabetes, hypertension, dyslipidaemia and cardiovascular diseases. Finally, we present the screening protocols for both hepatocellular carcinoma and extrahepatic malignancies in these patients.     

Non-alcoholic fatty liver disease,obesity and the metabolic syndrome

Nonalcoholic fatty liver disease (NAFLD) is now recognized as the most common cause of chronic liver disease worldwide. Its prevalence has increased to more than 30% of adults in developed countries and its incidence is still rising. The majority of patients with NAFLD have simple steatosis but in up to one third of patients, NAFLD progresses to its more severe form nonalcoholic steatohepatitis (NASH). NASH is characterized by liver inflammation and injury thereby determining the risk to develop liver fibrosis and cancer. NAFLD is considered the hepatic manifestation of the metabolic syndrome. However, the liver is not only a passive target but affects the pathogenesis of the metabolic syndrome and its complications. Conversely, pathophysiological changes in other organs such as in the adipose tissue, the intestinal barrier or the immune system have been identified as triggers and promoters of NAFLD progression. This article details the pathogenesis of NAFLD along with the current state of its diagnosis and treatment.     

PNPLA3 I148M and response to treatment for hepatic steatosis: A systematic review

Background

It is unclear whether the patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 C-to-G single nucleotide polymorphism, resulting in the substitution of isoleucine to methionine at position 148 (I148M), impedes regression of hepatic steatosis when treating non-alcoholic fatty liver disease (NAFLD).

Objectives

Investigate if carriage of the PNPLA3 148M allele affects the anti-steatotic efficacy of all possible anti-NAFLD interventions, identify gaps in current knowledge and provide guidance for individual treatment.

Methods

Research available in public databases was searched up to 13 November 2022. Studies were included if a treatment in NAFLD patients decreased hepatic steatosis in the pooled patient group or a PNPLA3 I148M polymorphism subgroup (II/IM/MM). The risk of bias was assessed using the Cochrane Risk-Of-Bias 2 Tool and the Newcastle–Ottawa Scale.

Results

Moderate evidence indicates that NAFLD patients homozygous for the PNPLA3 148M allele benefit less or not at all from omega-3 carboxylic acids to decrease liver fat, while the PNPLA3 148I allele shows moderate benefit. Low evidence suggests that interventions employing lifestyle changes are more effective to reduce liver fat in NAFLD patients homozygous for the PNPLA3 148M allele compared to patients with wild-type PNPLA3.

Conclusions

NAFLD patients homozygous for the PNPLA3 148M allele might not benefit from omega-3 carboxylic acids to reduce hepatic steatosis in contrast to patients with wild-type PNPLA3. Instead, patients with two PNPLA3 148M alleles should be especially advised to adopt lifestyle changes. Genotyping for PNPLA3 I148M should be encouraged in therapeutic studies for NAFLD.

Registration Number (Prospero)

CRD42022375028.     

非酒精性脂肪性肝病发生及进展的危险因素

非酒精性脂肪性肝病(NAFLD)的患病率逐年增加,目前成为我国成年人中最常见的慢性肝病之一。NAFLD可由非酒精性肝脂肪变性进展为非酒精性脂肪性肝炎、肝硬化、肝细胞癌及NAFLD相关性心血管事件、死亡等重大疾病。现对NAFLD发生的危险因素以及进展为肝纤维化、肝硬化、肝癌、相关心血管事件和死亡等重大疾病的相关危险因素进行综述,以便进一步探讨NAFLD发生发展的机制,降低NAFLD的患病率,减缓NAFLD的进展程度,降低相关疾病的病死率。     

A cross-sectional study of the public health response to non-alcoholic fatty liver disease in Europe

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Fatty liver disease in children: eat now pay later

Introduction  

With the recent epidemic in childhood obesity, nonalcoholic fatty liver disease (NAFLD) has become an emerging problem and a common cause of chronic liver disease in children.