Expression of adiponectin and its receptors in livers of morbidly obese patients with non-alcoholic fatty liver disease

Background and Aim:  Obesity is one of the risk factors for non-alcoholic fatty liver disease (NAFLD) and a common disease that comprises simple steatosis and non-alcoholic steatohepatitis (NASH), and can eventually lead to liver cirrhosis. Adiponectin is an adipocyte-derived protein that has anti-obesity, antidiabetic and anti-inflammatory properties, and is considered to possess a hepatoprotective function. Its role in the development and progression of NAFLD in morbidly obese patients is unknown. In this study, we examined the expression levels of adiponectin and its receptors in liver biopsies of morbidly obese patients and then determined whether there was an association with the disease severity.
Methods:  Liver biopsies from 30 morbidly obese patients (18 NASH vs 12 steatosis) were analyzed. The needle core biopsies were subjected to routine histological examination and stained immunohistochemically for adiponectin, adiponectin receptor I (adipoRI) and receptor II (adipoRII).
Results:  The two groups were comparable with respect to body mass index, age and gender distribution. The expression of adiponectin decreased in liver biopsies with NASH as compared to those with simple steatosis (1.61 ± 0.70 vs 2.25 ± 0.75, P  = 0.028). Spearman's rank correlation coefficient analysis showed that the staining intensity of adiponectin negatively correlated with the grade of inflammation ( r  = −0.368, P  = 0.045) and stage of fibrosis ( r  = −0.380, P  = 0.038). There was no significant difference in expression of adipoRI and adipoRII between the two groups.
Conclusion:  These findings indicate that decreased liver adiponectin expression may play a role in the development and progression of NAFLD, from simple steatosis to NASH, in morbidly obese patients.     

Non-alcoholic steatohepatitis with normal aminotransferase values

AIM： To investigate the aspects of liver histology in patients with non-alcoholic steatohepatitis （NASH） who had normal aminotransferase levels. METHODS： Thirty-four patients diagnosed with liver steatosis by ultrasonographic examination participated in the study. We compared all non- alcoholic fatty liver disease and NASH cases, according to aminotransferase level, aspartate aminotransferase （AST）/alanine aminotransferase （ALT） ratio and presence of metabolic syndrome. RESULTS： Sixteen of 25 patients with high aminotransferase levels were diagnosed with NASH and nine with simple fatty liver according to liver histology. Among the nine patients with normal aminotransferase levels, seven had NASH and two had simple fatty liver. The patients with normal and high liver enzyme levels had almost the same prevalence of NASH and metabolic syndrome. Liver histology did not reveal any difference according to aminotransferase levels and AST/ALT ratio. CONCLUSION： Aminotransferase levels and AST/AIT ratio do not seem to be reliable predictors for NASH. Despite numerous non-invasive biomarkers, all patients with fatty liver should undergo liver biopsy.     

Chitotriosidase gene expression in Kupffer cells from patients with non-alcoholic fatty liver disease

BACKGROUND AND AIMS: Non-alcoholic steatohepatitis (NASH) is a clinicopathological condition characterised by a necroinflammatory disorder with fatty infiltration of the hepatocytes. The molecular mechanisms involved in the anomalous behaviour of liver cells have only partially been determined. Human chitotriosidase (Chit) is a chitinolytic enzyme mainly produced by activated macrophages. The aim of this study was to investigate the expression of the chitinase-like gene in Kupffer cells, to determine how chitotriosidase may be implicated in the progression from uncomplicated steatosis to steatohepatitis with progressive fibrosis. METHODS: 75 subjects were studied: 40 with NASH, 20 with simple steatosis, and 15 normal controls. Kupffer cells obtained from liver biopsies were used to detect CHIT expression, superoxide anion (O2-), lipid peroxidation, and tumour necrosis factor alpha (TNFalpha) and ferritin levels. RESULTS: CHIT expression differed markedly in livers from normal controls and in those from patients with simple steatosis or non-alcoholic steatohepatitis. A significant correlation between mRNA CHIT and O2-, lipid peroxidation, TNFalpha, and ferritin levels was observed in both NASH and simple steatosis. CONCLUSIONS: Human Kupffer cells in NASH patients overproduce chitotriosidase. At the highest levels of production, this enzyme may play a role in increasing the risk for a poor outcome in steatohepatitis.     

Influence of TNF gene polymorphisms in Japanese patients with NASH and simple steatosis

BACKGROUND/AIMS: Tumor necrosis factor (TNF) is considered to play a role in the second hit of non-alcoholic steatohepatitis (NASH). To clarify the effects of TNF in NASH we investigated TNF gene polymorphisms that might influence TNF production were investigated. METHODS: We analyzed 102 patients with non-alcoholic fatty liver disease (NAFLD; 36 with simple steatosis and 66 with NASH) and 100 control subjects. The serum level of soluble TNF receptor (sTNFR)-2 was measured. The TNF-alpha promoter region positions -1031, -863, -857, -308, and -238 and the TNF-beta gene Nco1 polymorphism site were investigated. RESULTS: The level of sTNFR-2 was significantly higher in NASH patients than in those with simple steatosis or control subjects. In the analysis of TNF gene polymorphisms, there were no significant deviations between the group of all NAFLD patients and the control subjects. The carrier frequencies of polymorphisms at positions -1031C and -863A were significantly higher in patients with NASH than in those with simple steatosis. In the multivariate analysis, TNF-alpha promoter polymorphisms proved to be significant independent factors distinguishing NASH from simple steatosis. CONCLUSIONS: TNF polymorphisms, which influence TNF production, might be associated with the progression of NAFLD.     

The i148m Pnpla3 polymorphism influences serum adiponectin in patients with fatty liver and healthy controls

ABSTRACT: BACKGROUND: Reduced adiponectin is implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH), and the I148M Patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphism predisposes to NAFLD and liver damage progression in NASH and chronic hepatitis C (CHC) by still undefined mechanisms, possibly involving regulation of adipose tissue function. Aim of this study was to evaluate whether the I148M PNPLA3 polymorphism influences serum adiponectin in liver diseases and healthy controls. METHODS: To this end, we considered 144 consecutive Italian patients with NAFLD, 261 with CHC, 35 severely obese subjects, and 257 healthy controls with very low probability of steatosis, all with complete clinical and genetic characterization, including adiponectin (ADIPOQ) genotype. PNPLA3 rs738409 (I148M) and ADIPOQ genotypes were evaluated by Taqman assays, serum adiponectin by ELISA. Adiponectin mRNA levels were evaluated by quantitative real-time PCR in the visceral adipose tissue (VAT) of 35 obese subjects undergoing bariatric surgery. RESULTS: Adiponectin levels were independently associated with the risk of NAFLD and with the histological severity of the disease. Adiponectin levels decreased with the number of 148 M PNPLA3 alleles at risk of NASH both in patients with NAFLD (p = 0.03), and in healthy subjects (p = 0.04). At multivariate analysis, PNPLA3 148 M alleles were associated with low adiponectin levels (<6 mg/ml, median value) independently of NAFLD diagnosis, age, gender, BMI, and ADIPOQ genotype (OR 1.67, 95% c.i. 1.07-2.1 for each 148 M allele). The p.148 M PNPLA3 variant was associated with decreased adiponectin mRNA levels in the VAT of obese patients (p < 0.05) even in the absence of NASH. In contrast, in CHC, characterized by adiponectin resistance, low adiponectin was associated with male gender and steatosis, but not with PNPLA3 and ADIPOQ genotypes and viral features. CONCLUSIONS: The I148M PNPLA3 variant is associated with adiponectin levels in patients with NAFLD and in healthy subjects, but in the presence of adiponectin resistance not in CHC patients. The I148M PNPLA3 genotype may represent a genetic determinant of serum adiponectin levels. Modulation of serum adiponectin might be involved in mediating the susceptibility to steatosis, NASH, and hepatocellular carcinoma in carriers of the 148 M PNPLA3 variant without CHC, with potential therapeutic implications.     

Adiponectin and its receptors in patients with chronic hepatitis C

BACKGROUND/AIMS: There is increasing interest in the influence of excess body weight and associated metabolic factors on the liver. In patients with non-alcoholic steatohepatitis, lower levels of adiponectin were associated with higher grades of hepatic steatosis and necroinflammatory activity, suggesting a pathophysiological role for this adipokine in liver disease. METHODS: We studied 194 consecutive patients with untreated chronic HCV, to assess the relationship between adiponectin and its receptors and hepatic steatosis, fibrosis and inflammation. RESULTS: Significant negative correlations between serum adiponectin and male gender, body mass index and serum insulin were observed. However, there was no association between serum adiponectin and stage of fibrosis and lower levels of serum adiponectin were associated with the presence of steatosis in males only. In contrast, there was a significant increase in serum adiponectin and hepatic adiponectin immunoreactivity with increasing inflammation. The hepatic mRNA expression of the adiponectin receptors, AdipoR1 and AdipoR2, displayed significant but opposite associations with phosphoenolpyruvate carboxykinase (PEPCK) gene expression, a substitute marker of hepatic insulin sensitivity. CONCLUSIONS: In patients with chronic HCV, adiponectin was associated with steatosis only in males and was paradoxically increased with inflammation. Our results suggest that the role of adiponectin in chronic liver diseases may be linked to gender and etiology.     

Usefulness of a combined evaluation of the serum adiponectin level, HOMA-IR, and serum type IV collagen 7S level to predict the early stage of nonalcoholic steatohepatitis

OBJECTIVE: Since nonalcoholic steatohepatitis (NASH) may progress to cirrhosis, it is important to differentiate NASH from simple steatosis, especially in its early stages. However, a liver biopsy cannot be performed in all patients with nonalcoholic fatty liver disease (NAFLD). We herein investigated whether serum biochemical markers are useful for predicting early-stage NASH. METHOD: Nineteen patients with simple steatosis and 66 patients with early-stage NASH (stage 1-2 in Brunt's criteria) were studied. The area under the receiver operating characteristic curve (AUC) was used to illustrate the diagnostic ability of serum biochemical parameters to distinguish between simple steatosis and early-stage NASH. RESULTS: The serum adiponectin level was found to be significantly lower with early-stage NASH group (3.6 mug/mL) than in the simple steatosis group (6.0 mug/mL) (P < 0.001). The AUC was high (0.765) in the early-stage NASH group, and it was also the highest among all other markers. The sensitivity of the serum adiponectin level in the diagnosis of early-stage NASH was 68%, which was higher than for any other factors, while its specificity was 79%. The corresponding sensitivity and specificity of HOMA-IR were 51% and 95%, respectively. For type IV collagen 7S, sensitivity was 41% and specificity 95%. The sensitivity of the combination of three markers was 94%, with a specificity of 74%. CONCLUSION: Approximately 90% of the patients with early-stage NASH can be predicted by a combined evaluation of the serum adiponectin level, HOMA-IR, and serum type IV collagen 7S level.     

Plasma adiponectin is decreased in nonalcoholic fatty liver disease

OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver-related morbidity and is frequently associated with obesity and metabolic syndrome. The recently discovered hormone adiponectin is produced by adipose tissue, and low plasma adiponectin is considered a key factor in the development of the insulin resistance underlying metabolic syndrome. Animal studies suggest that adiponectin may protect against non-alcoholic steatohepatitis, but direct evidence in humans is lacking. We therefore conducted this study to assess the relationship between plasma adiponectin and nonalcoholic fatty liver disease to explore its role in the pathogenesis of this disease. DESIGN AND METHODS: We measured plasma adiponectin and anthropometric, biochemical, hormonal and metabolic correlates in a group of 17 NAFLD patients with diagnosis confirmed by biopsy, and 20 controls with comparable age, body-mass index and sex. Furthermore we compared plasma adiponectin in patients with simple steatosis and steatohepatitis. RESULTS: Plasma adiponectin was significantly lower in NAFLD patients than controls (5.93+/-0.45 vs 15.67+/-1.60ng/ml). Moreover, NAFLD patients were significantly more insulin resistant while having similar serum leptin. Adiponectin was similar in simple steatosis and in steatohepatitis (6.16+/-0.78 vs 5.69+/-0.49ng/ml). An inverse correlation was observed between adiponectin and homeostatic model assessment (HOMA) of insulin resistance (P = 0.008), while adiponectin did not correlate with serum transaminases and lipid values. CONCLUSIONS: These data support a role for low circulating adiponectin in the pathogenesis of NAFLD and confirm the strict association between reduced adiponectin production by adipose tissue, NAFLD and insulin resistance.     

Is adiponectin involved in the pathogenesis of nonalcoholic steatohepatitis? A preliminary human study

BACKGROUND: Animal studies have suggested that adiponectin may play a role in the pathogenesis of alcoholic and nonalcoholic fatty liver disease. Studies are limited that evaluated the role of adiponectin in the pathogenesis of nonalcoholic steatohepatitis (NASH). METHODS: To further our understanding of the role of adiponectin in the pathogenesis of NASH, the following studies were conducted. Serum adiponectin was measured and correlated with anthropometric and nutritional variables in 21 patients with biopsy-proven NASH and 19 age-, gender-, body mass index-, and body fat-matched controls. The effect of a mixed meal on serum adiponectin levels in a subgroup of patients (n = 24) with NASH and controls was assessed. In a separate cohort, liver samples belonging to healthy (n = 11), steatotic (n = 12), and NASH (n = 12) patients were used to further explore the role of adiponectin by measuring the expression of adiponectin and adiponectin receptor (AdipoR2) mRNA. RESULTS: Patients with NASH had significantly lower levels of serum adiponectin than controls (4.9 +/- 2.7 vs. 7.3 +/- 3.5 microg/mL, P = 0.02). While no significant correlation existed between serum adiponectin and anthropometric or nutritional variables, it was independently associated with age, high density lipoprotein, and triglycerides. Mixed meal had no effect on serum adiponectin either in patients with NASH or in controls. There was no expression of adiponectin mRNA in any of liver samples studied. However, AdipoR2 mRNA expression was higher in NASH than in steatotic and normal liver tissue. CONCLUSION: These data show that adiponectin may have a role in the pathogenesis of human NASH and should be investigated further.     

Prediction of Nonalcoholic Fatty Liver Disease Via a Novel Panel of Serum Adipokines

Considering limitations of liver biopsy for diagnosis of nonalcoholic liver disease (NAFLD), biomarkers’ panels were proposed. The aims of this study were to establish models based on serum adipokines for discriminating NAFLD from healthy individuals and nonalcoholic steatohepatitis (NASH) from simple steatosis.This case-control study was conducted in patients with persistent elevated serum aminotransferase levels and fatty liver on ultrasound. Individuals with evidence of alcohol consumption, hepatotoxic medication, viral hepatitis, and known liver disease were excluded. Liver biopsy was performed in the remaining patients to distinguish NAFLD/NASH. Histologic findings were interpreted using “nonalcoholic fatty liver activity score.” Control group consisted of healthy volunteers with normal physical examination, liver function tests, and liver ultrasound. Binary logistic regression analysis was applied to ascertain the effects of independent variables on the likelihood that participants have NAFLD/NASH.Decreased serum adiponectin and elevated serum visfatin, IL-6, TNF-a were associated with an increased likelihood of exhibiting NAFLD. NAFLD discriminant score was developed as the following: [(−0.298 × adiponectin) + (0.022 × TNF-a) + (1.021 × Log visfatin) + (0.709 × Log IL-6) + 1.154]. In NAFLD discriminant score, 86.4% of original grouped cases were correctly classified. Discriminant score threshold value of (−0.29) yielded a sensitivity and specificity of 91% and 83% respectively, for discriminating NAFLD from healthy controls. Decreased serum adiponectin and elevated serum visfatin, IL-8, TNF-a were correlated with an increased probability of NASH. NASH discriminant score was proposed as the following: [(−0.091 × adiponectin) + (0.044 × TNF-a) + (1.017 × Log visfatin) + (0.028 × Log IL-8) − 1.787] In NASH model, 84% of original cases were correctly classified. Discriminant score threshold value of (−0.22) yielded a sensitivity and specificity of 90% and 66% respectively, for separating NASH from simple steatosis.New discriminant scores were introduced for differentiating NAFLD/NASH patients with a high accuracy. If verified by future studies, application of suggested models for screening of NAFLD/NASH seems reasonable.     

Beyond insulin resistance in NASH: TNF-alpha or adiponectin?

Adiponectin has antilipogenic and anti-inflammatory effects, while tumor necrosis factor alpha (TNF-alpha) reduces insulin sensitivity and has proinflammatory effects. We examined (1) the extent to which hypoadiponectinemia and TNF-alpha activation are features of nonalcoholic steatohepatitis (NASH) and (2) whether serum levels of these markers correlate with the severity of histological changes in 109 subjects with nonalcoholic fatty liver disease (NAFLD), including 80 with NASH and 29 with simple steatosis. By multivariate analysis, subjects with NASH had reduced adiponectin level and increased TNF-alpha and soluble TNF receptor 2 (sTNFR2)-but not leptin levels, compared with controls matched by age, sex, and body mass index; these differences were independent of the increased insulin resistance (by homeostasis model [HOMA-IR]) in NASH. When compared with simple steatosis, NASH was associated with lower adiponectin levels and higher HOMA-IR, but there were no significant differences in the levels of TNF-alpha and sTNFR2. The majority of subjects with steatohepatitis (77%) had adiponectin levels less than 10 microg/mL and HOMA-IR greater than 3 units, but only 33% of those with pure steatosis had these findings. HOMA-IR and low serum adiponectin were also independently associated with increased grades of hepatic necroinflammation. In conclusion, hypoadiponectinemia is a feature of NASH independent of insulin resistance. Reduced adiponectin level is associated with more extensive necroinflammation and may contribute to the development of necroinflammatory forms of NAFLD.     

Combined pantethine and probucol therapy for Japanese patients with non-alcoholic steatohepatitis

Aims: To evaluate the efficacy and mechanism of combined pantethine and probucol therapy in Japanese patients with non-alcoholic steatohepatitis (NASH), liver function, serum cytokines, serum adiponectin and liver biopsy findings were investigated. Methods: Sixteen patients with NASH and hyperlipidemia were treated with pantethine (600 mg/day) and probucol (500 mg/day) for 48 weeks. Results: The mean pretreatment aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were 66 IU/L and 113 IU/L, respectively, which showed a significant decrease with treatment to 33 IU/L and 51 IU/L (P < 0.01 and P < 0.05), respectively. Total cholesterol was also significantlydecreased (P < 0.01). In addition, the mean serum TGF-beta level was significantly decreased, while the mean serum level of high molecular adiponectin was increased. In eight patients, liver biopsy was performed both before and after treatment. In four of these patients, inflammation was improved, and fibrosis was improved in two patients. No side-effects of this treatment were noted. Conclusion: Combined pantethine and probucol therapy was safe and effective for Japanese NASH patients, with its efficacy being mediated through adiponectin and TGF-beta.     

Obesity and non-alcoholic fatty liver disease in chronic hepatitis C

BACKGROUND: Superimposed non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) may affect HCV-related fibrosis. We performed a study to determine the relationship between NAFLD and chronic hepatitis C. METHODS: One hundred and twenty patients with chronic hepatitis C and available liver biopsies were included. Baseline liver biopsies were read by 1 hepatopathologist using Metavir, as well as a fatty liver pathology protocol. Patients' baseline clinical, demographic, and virologic data were associated with the extent of steatosis (>33% vs. < or =33%), the type of fatty liver (no steatosis vs. steatosis only vs. NASH), and the stage of fibrosis seen on the liver biopsy. RESULTS: Seventy percent of patients were men and 80% were white. The mean age was 47.48+/-5.70 years, mean BMI was 29.01 +/-5.01 kg/m, and mean waist to hip ratio (W/H) was 0.90+/-0.08. Patients with higher grade of steatosis had higher BMI (32.83+/-6.26 vs. 28.49+/-4.62, P = 0.034), more likely to have genotype 3 (21.4% vs. 5.7%, P = 0.037) and advanced fibrosis (92.9% vs. 62.3%, P = 0.033) than those with lower grade of steatosis. Of these, only HCV-genotype 3 remained independently associated with higher grade of steatosis. When patients with superimposed NASH (n = 22) were compared with those with only steatosis (n = 49) and those without steatosis (n = 49), patients with superimposed NASH had more evidence of obesity (BMI: 30.64+/-5.23 vs. 29.90+/-5.35 vs. 27.33+/-4.07, P = 0.008; W/H: 0.97+/-0.06 vs. 0.91+/-0.08 vs. 0.87+/-0.07, P < 0.001), more commonly infected with HCV genotype 3 (14% vs. 12% vs. 0%, P = 0.036) and had more advanced fibrosis (95.5% vs. 75.5% vs. 42.9%, P < 0.001). Race, gender, and age did not affect extent of steatosis or presence of superimposed NASH. CONCLUSION: In conclusion, markers of obesity (BMI and W/H) and HCV genotype 3 are associated with the extent of steatosis and type of fatty liver. Higher grade of steatosis and presence of superimposed NASH are both associated with advanced hepatic fibrosis.     

Predictors reflecting the pathological severity of non-alcoholic fatty liver disease: comprehensive study of clinical and immunohistochemical findings in younger Asian patients

BACKGROUND AND AIMS: The spectrum of non-alcoholic fatty liver disease (NAFLD) ranges from simple steatosis to severe steatohepatitis (NASH). The aim of our study was to identify clinical predictors distinguishing NASH from steatosis and to study the pathogenesis of NASH in a young Korean population. METHODS: Clinical and biochemical variables from 39 biopsied NAFLD patients were retrospectively analyzed. All liver biopsy specimens were immunohistochemically examined for Kupffer cells (CD68, CD14), as well as expression of tumor necrosis factor-alpha (TNF-alpha) and mitochondrial uncoupling protein 2 (UCP-2). RESULTS: There were no significant differences in serum biochemistry between the two groups (15 steatosis vs 24 NASH). There was a significant difference between the body mass index (BMI) values (kg/m(2)) of the NASH (28.4 +/- 3.4 kg/m(2)) and steatosis (25.8 +/- 2.8 kg/m(2)) patients (P < 0.025), with a BMI of 28.9 kg/m(2) representing the best threshold for distinguishing NASH from steatosis patients. BMI was significantly related to the degree of fibrosis (P < 0.01). CD68+ Kupffer cells were more common in the livers of NASH patients (P < 0.05), and TNF-alpha and UCP-2 were expressed in all NASH specimens and were related with the severity of inflammation and fibrosis (P < 0.05). CONCLUSIONS: BMI could be used to distinguish NASH from steatosis in younger Korean patients. A high BMI with a low alanine aminotransferase (ALT) value tended to suggest the presence of severe fibrosis in NASH, while the number of CD68+ Kupffer cells and the staining intensity of TNF-alpha and UCP-2 were correlated with general pathologic severity in patients with NAFLD.     

Noninvasive predictors for liver fibrosis in patients with nonalcoholic steatohepatitis

AIM: To evaluate certain anthropometric, clinical and laboratory features indicating liver fibrosis in nonalcoholic steatohepatitis and to establish the noninvasive markers for liver fibrosis.METHODS: Eighty-one patients (40 male, 41 female) who were diagnosed with fatty liver by ultrasonographic examination and fulfilled the inclusion criteria participated in the study. Anamnesis, anthropometric, clinical and laboratory features of all cases were recorded and then liver biopsy was performed after obtaining patient consent. Steatosis, necroinflammation and liver fibrosis were examined according to age ≥ 45, gender, body mass index, central obesity, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) > 1, γ-glutamyltransferase (GGT)/ALT > 1, platelet count, insulin, c-peptide levels and the presence of hypertension, diabetes, hypertriglyceridemia and insulin resistance.RESULTS: Eighty-one patients with non-alcoholic steatohepatitis (NASH) enrolled in the study. 69 of 81 patients were diagnosed with NASH, 11 were diagnosed with simple fatty liver and 1 was diagnosed with cirrhosis. AST/ALT > 1, GGT/ALT > 11, high serum ferritin and fasting insulin levels, the presence of diabetes, hypertension, hypertriglyceridemia and insulin resistance seemed to enhance the severity of steatosis, necroinflammation and fibrosis but these results were not statistically significant.CONCLUSION: Liver steatosis and fibrosis can occur in individuals with normal weight. There was no significant concordance between severity of liver histology and the presence of predictors for liver fibrosis including metabolic risk factors.     

Adiponectin and Its Receptors in Chronic Hepatitis B Patients With Steatosis in China

Background

HBV infection is a serious public health problem worldwide, which can contribute to the incidence of chronic hepatitis B (CHB), cirrhosis, and hepatocellular carcinoma (HCC).

Objectives

In the present report, we assessed the association between adiponectin, its receptors and hepatic steatosis, fibrosis, and inflammation with hepatitis B virus.

Patients and Methods

Liver biopsies from 89 patients with untreated chronic hepatitis B (34 steatosis vs. 55 without steatosis) were analyzed; liver biopsies from 50 healthy adults were used as control. The liver biopsies were subjected to routine histological examination, and stained immunohistochemically for adiponectin and adiponectin receptor2 (adipoR2).

Results

The two groups were found to be comparable with respect to demographic, biochemical, metabolic, histological, and viral characteristics. BMI, γ-GT, FPG, insulin, and insulin sensitivity estimated by the HOMA index were significantly higher in patients with steatosis. The viral load of HBV and HBeAg positivity was higher in patients with steatosis than those without steatosis. High serum adiponectin levels were significantly correlated with abnormal serum ALT level (vs. normal ALT, P = 0.000), and HBV genotype C (vs. genotype B, P = 0.018). In patients with chronic HBV, the insulin sensitizing adipokine adiponectin, and its receptor AdipoR2were associated with steatosis. While adiponectin may becorrelated with inflammation, adiponectin, and its receptors were not associated with viral factors.

Conclusions

Our results suggest that the role of adiponectin might be impaired in chronic hepatitis B with steatosis. Reduced hepatic expression of adiponectin and adipoR2 might be of pathophysiological relevance in CHB patients with steatosis. These findings indicated that reduced liver adiponectin expression may play an important role in the pathogenesis, and progression of CHB patients with steatosis. However, hepatic expression of adiponectin, and adipoR2 was not associated with various measures of HBV infection.     

Endocannabinoid receptor CB2 in nonalcoholic fatty liver disease.

BACKGROUND AND AIM: Fatty infiltration and fibrosis are major issues in chronic liver disease. Recent reports suggest a role for the endocannabinoid system in these processes. AIM: To characterize localization and expression of CB2 in normal liver and nonalcoholic fatty liver. METHODS: We studied 64 liver biopsies: eight were considered normal; 56 had a diagnosis of nonalcoholic fatty liver disease (NAFLD); 32 with nonalcoholic steatosis and 24 nonalcoholic steatohepatitis (NASH). CB2 immunolocalization was studied in 38 samples in paraffin blocks using immunohistochemistry, and a computerized semiquantitative analysis was carried out. CB2 mRNA expression was assessed through RT-PCR in 26 frozen liver samples and the ratio CB2/beta-actin was used to evaluate differences between groups. Statistical analysis was performed with central tendency measures and the Mann-Whitney U-test. We considered as significant differences those with a P-value <0.05. RESULTS: Neither parenchymal nor nonparenchymal cells in normal liver tissue react towards anti-CB2 antibodies. All the samples from patients with steatosis and nonalcoholic steatohepatitis showed hepatocellular immunoreactivity. Cholangiocytes were positive only in the NAFLD group. Normal liver tissue showed a normalized CB2/beta-actin ratio of 0.001+/-0.01, steatosis 6.52+/-17.3 (P=0.05 vs normal) and NASH 6.49+/-12.2 (P=0.06 vs normal and P=0.6 vs steatosis). CONCLUSION: CB2 receptors are expressed by hepatocytes in nonalcoholic fatty liver disease but not in normal liver.