Hepatocyte steatosis in HCV patients promotes fibrosis by enhancing TGF-β liver expression

Aim:  The objective of this study was to examine the relationship between TGF-β expression in steatotic liver and the stage and yearly progression rate of fibrosis in chronic hepatitis C (CHC) patients.
Methods:  We examined 44 CHC fatty liver patients, using 76 non-steatotic CHC patients as controls. The stage of hepatic fibrosis was assessed on a score scale. TGF-β expression was determined with the use of monoclonal serum and the ABC three-step method.
Results:  We demonstrated a positive correlation of steatosis with the stage of fibrosis ( P  < 0.05). No relationship of thiskind was found with the yearly progression rate of fibrosis ( P  > 0.09). In steatotic biopsies, TGF-β expression index in portal spaces and lobules was found to be higher as compared to TGF-β expression in biopsies without steatosis ( P  < 0.05).
Conclusion:  In CHC patients steatosis induces the development of fibrosis by elevating the hepatic expression of TGF-β.     

Worsening of steatosis is an independent factor of fibrosis progression in untreated patients with chronic hepatitis C and paired liver biopsies

BACKGROUND AND AIMS: Steatosis, a frequent histological finding in patients with chronic hepatitis C (CHC), has been suggested to influence liver fibrosis progression. The aim of the present study was to evaluate in patients with CHC and paired liver biopsies the relationship between the evolution of steatosis and that of fibrosis between the two biopsies. METHODS: Ninety six patients were selected according to the following criteria: absence of treatment; absence of cirrhosis at initial biopsy; and serum hepatitis B surface antigen and human immunodeficiency virus antibody negativity. Degrees of necroinflammatory activity, fibrosis, and steatosis grades were assessed in the two biopsies. In addition to histological lesions, parameters studied included the source of infection, duration of infection, body mass index, alcohol intake, alanine aminotransferase levels, hepatitis C virus genotype, and viral load. RESULTS: The mean interval between the two biopsies was 48 (32) months. Steatosis was found in 54% of patients at first biopsy, and was severe in 9%. Worsening of steatosis was observed in 34% of patients, stability in 50%, and improvement in 16%. Worsening of steatosis was significantly associated with hepatic fibrosis progression in patients with (p=0.03) or without (p<0.03) steatosis at diagnosis. Overall, fibrosis progression was observed in 31% of patients and stability in 69%. In a univariate analysis, fibrosis progression was associated with male sex (p=0.05), worsening of histological activity (p=0.04), and worsening of steatosis (p=0.0003). In a multivariate analysis, the only factor independently associated with fibrosis progression was worsening of steatosis (worsening v improvement/stability: odds ratio 4.7 (95% confidence interval 1.3-10.8); p=0.0001). CONCLUSIONS: Our results suggest that in untreated patients with CHC and serial liver biopsies, fibrosis progression is strongly associated with worsening of steatosis.     

Hepatic steatosis in chronic hepatitis B and C: predictors, distribution and effect on fibrosis

BACKGROUND/AIMS: Chronic hepatitis B (CHB) and C (CHC) are commonly associated with hepatic steatosis. The aims of this study were to investigate predictors of hepatic steatosis, and their impact on inflammation and fibrosis in CHB and CHC. METHODS: Consecutive patients with either CHB or CHC who underwent a liver biopsy at The Alfred Hospital between April and September 2002 were included. Histological analysis of liver biopsies was performed by two hepatopathologists blinded to the clinical data. RESULTS: Ninety-one patients were analysed including 17 patients with CHB and 74 with CHC. CHC genotype 3, C-peptide, glucose and waist circumference were independent predictors of extent of Brunt steatosis grade, while CHC genotype 3, C-peptide and waist circumference were independent predictors of microvesicular steatosis grade. Alcohol intake and age were predictors of hepatic fibrosis. There was a trend toward a correlation between both Brunt steatosis and microvesicular steatosis grades and fibrosis progression rate in CHC genotype non-3. CONCLUSIONS: Hepatic steatosis is common in chronic hepatitis B and C, and is associated with waist circumference, glucose, C-peptide and chronic hepatitis C genotype 3. Steatosis grade appears to relate to hepatic fibrosis progression rate in chronic hepatitis C genotype non-3.     

Lipid peroxidation in hepatic steatosis in humans is associated with hepatic fibrosis and occurs predominately in acinar zone 3

BACKGROUND AND AIMS: Hepatic steatosis has been shown to be associated with lipid peroxidation and hepatic fibrosis in a variety of liver diseases including non-alcoholic fatty liver disease. However, the lobular distribution of lipid peroxidation associated with hepatic steatosis, and the influence of hepatic iron stores on this are unknown. The aim of this study was to assess the distribution of lipid peroxidation in association with these factors, and the relationship of this to the fibrogenic cascade. METHODS: Liver biopsies from 39 patients with varying degrees of hepatic steatosis were assessed for evidence of lipid peroxidation (malondialdehyde adducts), hepatic iron, inflammation, fibrosis, hepatic stellate cell activation (alpha-smooth muscle actin and TGF-beta expression) and collagen type I synthesis (procollagen alpha1 (I) mRNA). RESULTS: Lipid peroxidation occurred in and adjacent to fat-laden hepatocytes and was maximal in acinar zone 3. Fibrosis was associated with steatosis (P < 0.04), lipid peroxidation (P < 0.05) and hepatic iron stores (P < 0.02). Multivariate logistic regression analysis confirmed the association between steatosis and lipid peroxidation within zone 3 hepatocytes (P < 0.05), while for hepatic iron, lipid peroxidation was seen within sinusoidal cells (P < 0.05), particularly in zone 1 (P < 0.02). Steatosis was also associated with acinar inflammation (P < 0.005). alpha-Smooth muscle actin expression was present in association with both lipid peroxidation and fibrosis. Although the effects of steatosis and iron on lipid peroxidation and fibrosis were additive, there was no evidence of a specific synergistic interaction between them. CONCLUSIONS: These observations support a model where steatosis exerts an effect on fibrosis through lipid peroxidation, particularly in zone 3 hepatocytes.     

Increased expression of Ob-Rb and its relationship with the overexpression of TGF-beta1 and the stage of fibrosis in patients with nonalcoholic steatohepatitis.

AIMS: The main aim of this study was to examine the relationship of the leptin system in steatosis and nonalcoholic steatohepatitis (NASH). The study also analysed the pathogenic role of the leptin system in the development of hepatic fibrosis and its relation with the TGF-beta1 system. MATERIALS AND METHODS: The study included 90 subjects, 55 with NASH and 35 with simple steatosis. Gene expression of leptin, leptin receptor and TGF-beta mRNA was analysed by real-time PCR on liver tissue. Leptin serum levels were determined by RIA. Leptin receptor expression was also assessed by immunohistochemistry. RESULTS: Increased expression was found for leptin receptor mRNA (P=0.0016) and its protein (P<0.05) in patients with NASH, especially those with fibrosis. There was a marked increase in gene expression of TGF-beta1 in patients with NASH (P=0.0002). A strong correlation was demonstrated between leptin receptor gene expression and TGF-beta1 gene expression (P=0.023). No leptin expression was found in the liver tissue. All patients showed a marked hyperleptinemia, which was closely related to the anthropometric characteristics analysed and independent of development or not of NASH. CONCLUSIONS: The results of the study demonstrate for the first time increased leptin receptor expression in liver tissue and its relationship with overexpression of TGF-beta1 and the degree of hepatic fibrosis.     

The histological course of nonalcoholic fatty liver disease: a longitudinal study of 103 patients with sequential liver biopsies

BACKGROUND/AIMS: The histological course of nonalcoholic fatty liver disease (NAFLD) remains undescribed. Therefore, we examined the liver histology of NAFLD patients who had undergone sequential liver biopsies. METHODS: Data on 103 patients who underwent serial liver biopsies in the absence of effective treatment were reviewed, and biopsies scored in a blind fashion. RESULTS: Mean interval between biopsies was 3.2+/-3.0 years (range 0.7-21.3). Fibrosis stage apparently progressed in 37%, remained stable in 34% and regressed in 29%. Severity of steatosis, inflammation, hepatocyte ballooning and Mallory's hyaline improved significantly. Aminotransferases decreased significantly between biopsies, paralleling improvement in steatosis and inflammatory features but not fibrosis stage. The rate of fibrosis change ranged from -2.05 to 1.7 stages/year. By multivariate analysis, diabetes (P = 0.007) and low initial fibrosis stage (P < 0.001) were associated with higher rate of fibrosis progression, as was higher body mass index (P = 0.008) when cirrhotics were excluded. CONCLUSIONS: Fibrosis in NAFLD progresses slowly over time with considerable variability in the rate of changes among patients. Changes of aminotransferases do not parallel changes in fibrosis stage. Diabetic patients with elevated BMI and low fibrosis stage are at risk for higher rates of fibrosis progression.     

Overweight and obesity, hepatic steatosis, and progression of chronic hepatitis C: a retrospective study on a large cohort of patients in the United States

BACKGROUND: Hepatic steatosis has been associated with chronic hepatitis C (CHC), but its prevalence, risk factors, and clinical significance remain to be determined. AIMS: The present study determined the frequency of, and risk factors for hepatic steatosis and its association with activity and progression of CHC in a large cohort of U.S. patients. METHODS: This is a retrospective study that utilized systematic chart review and statistical analyzes to investigate 324 U.S. patients with CHC from a university medical center and a regional VA medical center. RESULTS: The frequency of hepatic steatosis was 66.0%. We demonstrated that not only being obese, but also overweight (i.e. body mass index > or =25 kg/m(2)) was independently associated with hepatic steatosis. In our cohort of patients with CHC, hepatic steatosis, especially grade II/III steatosis, was significantly associated with elevated aspartate aminotransferase at entry, persistently elevated alanine aminotransferase, and stage III/IV fibrosis. Grade II/III steatosis, was significantly associated with a higher histology activity index as well. Multivariate analysis indicated that steatosis, especially grade II/III steatosis, was independently associated with stage III/IV fibrosis. CONCLUSIONS: Being overweight/obese serves as an independent risk factor for hepatic steatosis in U.S. patients with CHC. Steatosis accelerates activity and progression of CHC, and is independently associated with stage III/IV hepatic fibrosis in these patients.     

Progression of fibrosis in hepatitis C with and without schistosomiasis: correlation with serum markers of fibrosis

Serial liver biopsies are the gold standard by which the progression of fibrosis is evaluated. This longitudinal cohort study assessed the different rates in the progression of fibrosis using serial liver biopsies and serum fibrosis markers YKL-40 and PIIINP and the cytokines, transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNuF-alpha). A 10-year cohort study was performed in patients with hepatitis C virus (HCV) alone or HCV and schistosomiasis. Patients were enrolled at the time of acute HCV infection and prospectively evaluated with two liver biopsies (at entry and end of follow-up), and true rates in the progression of fibrosis were calculated per year. Serum YKL-40, N-terminal propeptide of collagen III (PIIINP), TGF-beta, and TNF-alpha were measured, as well as the expression of TGF-beta, TNF-alpha, and YKL-40 mRNA in liver tissue. A significant increase in the progression rates of fibrosis occurred in the coinfected group (0.61 +/- 0.13) compared with the HCV monoinfection group (0.1 +/- 0.06; P < .001)). The progression of fibrosis rate/year had a direct linear correlation for YKL-40 (r = 0.892, P < .001) and for PIIINP (r = 0.577, P < .01). YKL-40 showed a linear correlation with TGF-beta (r = 0.897, P < .001). Hepatic mRNA levels of YKL-40 and TGF-beta correlated with the serum levels, confirming a hepatic source for the elevated serum levels. In conclusion, serial cytokine and fibrosis markers can accurately determine the rate at which fibrosis is progressing, identifying both those with rapid fibrosis and those with stable disease.     

Hepatic steatosis in chronic hepatitis B patients is associated with metabolic factors more than viral factors

Background and Aims:  Hepatic steatosis is commonly seen in chronic hepatitis C (CHC) patients. It has been reported to be associated with both metabolic factors and viral factors, and affects the severity of fibrosis in CHC. However, the relationship between hepatic steatosis and chronic hepatitis B (CHB) is unclear. The aims of this study were to investigate the frequency of hepatic steatosis in CHB patients, to identify the factors associated with its presence, and assess the relationship between the stage of steatosis and the severity of fibrosis.
Methods:  Medical records of 153 adult patients with CHB who had undergone a liver biopsy within the past 4 years were included in the study.
Results:  Body mass index (BMI) and age of CHB patients with steatosis was significantly higher than the patients without steatosis ( P  < 0.05), as determined by the univariate analysis. Steatosis was found to correlate with the BMI values and alanine aminotransferase (ALT) levels, and ALT levels were associated with hepatitis B virus (HBV)–DNA levels and histology activity index (HAI) scores, stages of fibrosis were associated with the HAI score and HBV–DNA, as determined by the multivariate analysis. In contrast, there was no significant association between advanced stages of fibrosis and steatosis.
Conclusion:  Our data indicate that hepatic steatosis is more frequently present in CHB patients than in the general population. We hypothesize that steatosis in CHB patients may be due to metabolic factors and the ability of HBV to indirectly facilitate the development of steatosis. In the present study, steatosis in CHB patients was not found to be associated with the severity of fibrosis.     

Impact of steatosis on insulin secretion in chronic hepatitis C patients

OBJECTIVES: Liver steatosis is frequently observed in patients with chronic hepatitis C (CHC) and is an identified risk factor for progression of liver fibrosis. This study aimed to evaluate the relationship between steatosis and host/viral factors, and the correlation between steatosis and insulin secretion in CHC patients with normal glucose tolerance (NGT). METHODS: A total of 212 CHC patients were enrolled in this study. Insulin resistance and insulin secretion were determined in response to oral loading of 75 g glucose. Liver fibrosis and steatosis were quantified by the image analysis. RESULTS: Of the 212 CHC patients, 165 (78%) had steatosis, mostly of a mild degree. Multiple ordinal regression analysis revealed body mass index (BMI) (P= 0.011) as the main factor associated with severe steatosis. Of the 212 CHC patients, 148 (61%) showed NGT, and the serum insulin response to oral glucose loading in these NGT patients with steatosis was significantly different from that in patients with NGT but no steatosis. The peak insulin response occurred at 60 min in cases of mild steatosis, and at 90 min in patients with moderate or severe steatosis. The insulin level at 120 min in patients with severe steatosis was higher than that in those without steatosis. The total area under the response curve of insulin during OGTT in the patients with steatosis is higher than that in those without steatosis. CONCLUSION: Exaggerated insulin secretion was observed even in CHC patients with mild steatosis and NGT, suggesting the presence of insulin resistance. Exaggerated insulin secretion may accelerate the progression of liver fibrosis in CHC patients.     

Insulin resistance and diabetes increase fibrosis in the liver of patients with genotype 1 HCV infection

OBJECTIVES: Metabolic factors may affect the course of chronic hepatitis C (CHC). Insulin resistance (IR) determines steatosis, but its direct role in affecting progression of hepatic fibrosis is less clear. We aimed to assess whether increasing degrees of IR, up to overt diabetes, are linked to steatosis and higher stages of fibrosis in patients with CHC resulting from genotype 1 HCV (G1-HCV).
METHODS: Two hundred one consecutive patients with G1-HCV infection were evaluated by liver biopsy and anthropometric and metabolic measurements, including IR, by the homeostasis model assessment (HOMA). Nondiabetic patients were defined as insulin resistant if HOMA-IR was >2.7. All biopsies were scored by one pathologist for staging and grading (Scheuer), and graded for steatosis.
RESULTS: Ninety-six patients were noninsulin resistant (group 1), 76 were insulin resistant without diabetes (group 2), and 29 were diabetic (group 3). At multivariate analysis, fibrosis of ≥3 was independently associated with high necroinflammatory activity (odds ratio [OR] 2.994, 95% confidence interval [CI] 1.422–6.098), low platelets (OR 0.994, 95% CI 0.981–0.999), low cholesterol (OR 0.987, 95% CI 0.976–0.998), high ferritin (OR 1.002, 95% CI 1.001–1.004), and a high prevalence of IR (OR 2.692, 95% CI 1.463–4.954). Diabetic patients were twice as likely to have severe fibrosis (60%) than those with IR but no diabetes (30%) ( P = 0.006). The degree of steatosis and that of fibrosis were weakly associated with each other ( P = 0.42).
CONCLUSIONS: In subjects with CHC resulting from G1-HCV, IR and overt diabetes are major determinants of advanced fibrosis, regardless of the degree of steatosis, mainly in the presence of severe necroinflammation.     

Factors Influencing the Rate of Fibrosis Progression in Chronic Hepatitis C

Alcohol consumption, age at infection, and male gender have been identified as risk factors for faster fibrosis progression in patients with chronic hepatitis C (CHC). Yet the influence of liver steatosis, light to moderate alcohol consumption, or iron overload on this progression remains controversial. To analyze the effect of individual risk factors and their interaction on fibrosis progression in a group of patients with CHC and a definite date of infection, we studied 133 consecutive untreated patients. Covariates included were age, body mass index (BMI), gender, age at infection, alcohol intake, serum lipids, glycemia, serum ALT, AST, GGT, iron, and ferritin, grade and stage (METAVIR and Scheuer), and hepatic stainable iron (Perl's stain). The rate of fibrosis progression was inferred from the METAVIR score. By logistic regression analysis, hepatic steatosis (odds ratio [OR], 3.035; 95% confidence interval [CI], 1.16-7.93), serum ferritin levels higher than 290 ng/ml (OR, 5.5; 1.6-18.65), and light to moderate ethanol intake (1-50 g/day) (OR, 5.22; 1.5-17.67) were independently associated with faster fibrosis progression. There was no effect of interaction between these variables on the rate of fibrosis progression. Liver steatosis, serum ferritin levels, and light to moderate alcohol intake are associated with faster fibrosis progression in chronic hepatitis C. Combination of these factors did not further accelerate this progression. The impact of modification of these factors on progression should be tested in longitudinal studies.     

Combination of oxidative stress and steatosis is a risk factor for fibrosis in alcohol-drinking patients with chronic hepatitis C

BACKGROUND AND AIMS: Alcohol and HCV have been shown to interact in stimulating hepatic oxidative damage. Thus, we investigated the contribution of oxidative mechanisms in the progression of chronic hepatitis C (CHC) in alcohol consumers. METHODS: An increased IgG reactivity against lipid peroxidation-derived antigens was used as the marker for alcohol-induced oxidative damage in 125 CHC patients. RESULTS: Alcohol intake significantly increased the frequency of the subjects with elevated lipid peroxidation-related IgG. However, no association was evident between oxidative stress markers and the severity of steatosis, necroinflammation, or fibrosis. Multivariate analysis revealed that age (P= 0.014) and hepatic iron content (P= 0.034) were the only independent predictors of fibrosis in these patients. However, the risk of fibrosis in the subjects with both steatosis and oxidative stress-induced immune responses was 6- (OR 6.2, 95% CI 1.2-31.0) and 14-fold (OR 14.6, 95% CI 3.1-68.1) higher than in the subjects with steatosis alone or without steatosis, respectively. Multivariate analysis confirmed that the combination of steatosis and oxidative stress (P= 0.045) was, together with age (P= 0.021) and hepatic iron content (P= 0.027), an independent risk factor for fibrosis in CHC patients with alcohol intake. CONCLUSIONS: These results demonstrate that oxidative stress interacts with steatosis to promote the progression of CHC in alcohol-consuming patients.     

Hepatic steatosis and fibrosis in young men with treatment‐naïve chronic hepatitis B

Objectives: The clinical significance of liver steatosis has been studied because steatosis plays a role in the progression of liver fibrosis. Nevertheless, the impact of steatosis in the early stage of fibrosis in non‐obese young men with chronic hepatitis B (CHB) is poorly understood. Thus, the purpose of this study was to investigate the prevalence of hepatic steatosis, assess the relationship between hepatic steatosis and fibrosis and to assess the laboratory parameters for predicting clinically significant liver fibrosis in non‐obese young men with CHB. Methods: We prospectively evaluated liver biopsies in young male patients with CHBwith a serum alanine aminotransferase level of more than two times the upper limit of normal for at least 3 months before enrollment. Patients were excluded when they had co‐infection with another virus and prior antiviral treatment. Demographical, anthropometric and laboratory parameters were analysed. Liver steatosis, necroinflammation and fibrosis were also assessed. Results: A total of 86 young male patients with CHB were included in this study. The median age was 21 years (range, 20–26 years) and the median body mass index was 23.0 kg/m² (range, 18.0–28.3 kg/m²). Steatosis was present in 44 patients (51.2%). Significant fibrosis (beyond periportal fibrosis) was present in 50 patients (58.1%). Steatosis was associated with insulin, homeostasis model for insulin resistance (HOMA‐IR), total cholesterol and triglycerides. On multiple regression analysis, steatosis was independently associated with triglyceride and HOMA‐IR. Significant fibrosis was independently associated with γ‐glutamyltransferase (GGT) and necroinflammation activity. However, there was no significant association between significant fibrosis and the presence of steatosis. Conclusions: The prevalence of hepatic steatosis is a common finding in young male patients with CHB. Hepatic steatosis in CHB patients seems to be associated with insulin resistance, but it is not associated with hepatic fibrosis. GGT levels can provide useful information on the stage of CHB.     

Virus-induced over-expression of protein phosphatase 2A inhibits insulin signalling in chronic hepatitis C

BACKGROUND/AIMS: Hepatitis C virus (HCV) infection disturbs glucose and lipid metabolism contributing to the development of liver steatosis, insulin resistance and type 2 diabetes mellitus. On the other hand, insulin resistance and steatosis have been found to be associated with increased rates of fibrosis progression and lower rates of response to interferon therapy in chronic hepatitis C (CHC). The molecular mechanisms contributing to insulin resistance in CHC are not well understood. We have shown previously that protein phosphatase 2A (PP2A) is over-expressed in biopsies from patients with CHC. In this study, we tested if PP2A over-expression leads to insulin resistance. METHODS: We studied insulin signalling in cell lines that allow the regulated over-expression of HCV proteins and of the PP2A catalytic subunit (PP2Ac). Insulin signalling and PP2Ac expression were also studied in HCV transgenic mice and in liver biopsies from patients with CHC. RESULTS: Over-expression of PP2Ac in cells inhibited insulin signalling by dephosphorylation of PKB/Akt. PP2Ac over-expression and impaired insulin signalling were found in the liver of HCV transgenic mice and in liver biopsies of patients with CHC. CONCLUSIONS: HCV-induced over-expression of PP2A in the liver contributes to the pathogenesis of insulin resistance in patients with CHC.     

Obesity-related non-alcoholic steatohepatitis and TGF-beta1 serum levels in relation to morbid obesity

Non-alcoholic steatohepatitis (NASH) can vary from mild hepatic inflammation and steatosis to cirrhosis, and is most frequently associated with obesity, Type 2 diabetes mellitus, hypertension, and the female gender. The prevalence of fatty liver and NASH in the general population is 20% and 3%, respectively. In Western countries, 15-20% of the population is obese and 74-90% of them exhibit fatty changes in liver biopsies. We assessed the prevalence of NASH in morbidly obese patients and evaluated serum TGF-beta1 concentrations in different stages of liver fibrosis. Thirty-five obese patients were evaluated, nine male and 26 female. Their mean body mass index (BMI) was 43.62 +/- 7.92 kg/m2. Liver biopsies were evaluated by light microscopy; graded and staged according to Brunt's system. Serum obtained from patients was used to detect TGF-beta1 concentrations by an ELISA method. Serum alanine transaminase (ALT) levels were elevated in four of the patients and the mean level was 49.98 +/- 94.7 (8-65 IU/L). NASH was diagnosed in 32 (91%) of the biopsies, and the most common pattern seen was mixed, predominantly macrovesicular steatosis. Some degree of fibrosis was seen in 34 (97%) of the biopsies and 22 (63%) were at stage 2 (range 1-3). Serum concentrations of TGF-beta1 had no relationship with the stages of fibrosis. In conclusion, NASH and fibrosis are common in our obese patients, as observed in other studies. TGF-beta1 may play a key role in liver fibrogenesis.     

Elevated miR-33a and miR-224 in steatotic chronic hepatitis C liver biopsies

AIM: To assess the expression of selected microRNAs (miRNA) in hepatitis C, steatotic hepatitis C, noninfected steatotic and normal liver tissues.METHODS: The relative expression levels of miR-21, miR-33a, miR-96, miR-122, miR-125b, miR-221 and miR-224 were determined in 76 RNA samples isolated from 18 non-steatotic and 28 steatotic chronic hepatitis C (CHC and CHC-Steatosis, respectively) cases, 18 non-infected, steatotic liver biopsies of metabolic origin (Steatosis) and 12 normal formalin-fixed paraffin-embedded liver tissues using TaqMan MicroRNA Assays. All CHC biopsy samples were obtained prior to initiating therapy. Patients’ serum biochemical values, which included glucose, triglyceride, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl-transferase (GGT), alkaline phosphatase (AP), were obtained and correlated with relative miRNA expression.RESULTS: When compared with control non-infected liver samples, miR-122 and miR-221 levels were reduced in CHC-Steatosis (P < 0.03) and in CHC, CHC-Steatosis and Steatosis (P < 0.01). Alternatively, the expression of miR-33a and miR-224 were elevated in CHC-Steatosis and Steatosis in comparison to control tissue (P < 0.01). The levels of miR-33a and miR-224 in CHC-Steatosis (P < 0.02) and miR-224 in Steatosis (P < 0.001) were increased in comparison to CHC samples. By contrast, the expression of miR-21 did not differ statistically between diseased and normal liver samples. Levels of miR-33a correlated negatively with serum AST and AP levels in Steatosis as well as with necroinflammatory grade in CHC, whereas miR-21 correlated positively with AST in Steatosis and displayed negative correlation with triglyceride level in CHC-Steatosis. In contrast, miRNA levels were not correlated with ALT, GGT, cholesterol levels or fibrosis stage.CONCLUSION: Differences in miRNA expression were observed between CHC and steatotic CHC, CHC and steatotic liver, but not between steatotic CHC and steatotic liver of metabolic origin.     

慢性乙型肝炎患者肝细胞脂肪变的发生率及其危险因素分析

目的 了解肝细胞脂肪变在慢性乙型肝炎(CHB)患者中的发生率及危险因素.方法 对2005年1月-2007年6月经肝活组织检查证实的CHB患者进行回顾性研究,剔除合并HCV和HW等病毒感染及其他慢性肝病.调查肝细胞脂肪变在CHB患者中的发生率及其变化趋势,分析肝脂肪变与相关的人口学特征、病毒学指标和生物化学指标、以及肝组织学改变之间的关系.结果 在1915例CHB患者中,男1497例,女418例,平均年龄(30.7±9.5)岁.肝组织病理显示肝细胞脂肪变发生率为13.6%(260/1915),并呈逐年增高趋势(2005-2007年分别为11.2%、14.30、17.9%).肝细胞脂肪变程度<30%(FI)的患者占90.4%;男性肝脂肪变(15.2%,228/1497)明显高于女性(7.7%,32/418).有肝脂肪变的CHB患者,其体重指数、年龄、空腹血糖和尿酸明显高于无肝脂肪变患者,t值分别为6.01,3.60,4.72,9.55,P值均<0.01.超重、肥胖、糖尿病,血脂异常和高尿酸血症患病率也明显高于无肝脂肪变患者,x2值分别为17.00,169.45,6.12,116.67,76.34,P值均<0.05.轻度CHB患者肝脂肪变发生率(17.8%)显著高于慢性HBsAg携带者(8.6%)以及CHB中度(9.4%)和重度(7.7%)患者;同样,炎症活动度G1患者肝脂肪变发生率(19.8%)和纤维化程度S1患者肝脂肪变发生率(19.1%)分别显著高于G0、G2、G3和G4(分别为10.3%、11.5%、9.3%和7.3%)和S0、S2、S3和S4(分别为10.8%、13.3%、7.1%、7.4%)患者;肝脂肪变发生率与HBeAg状态及HBV DNA水平无相关关系.多元回归分析显示:体重指数、甘油三酯、载脂蛋白B、尿酸和空腹血糖与CHB患者肝脂肪变的发生密切相关.结论 肝细胞脂肪变在CHB患者中并不少见,其发生主要由患者的代谢因素所致,而与HBV本身无关,肝细胞脂肪变发生与肝脏组织病理损伤程度之间也无明显相关.     

Steatosis and liver cell apoptosis in chronic hepatitis C: a mechanism for increased liver injury

Steatosis is increasingly recognized as a cofactor influencing the progression of fibrosis in chronic hepatitis C; however, the mechanisms by which it contributes to liver injury remain uncertain. We studied 125 patients with chronic hepatitis C to assess the effect of steatosis on liver cell apoptosis and the expression of Bcl-2, Bcl-x(L), Bax, and tumor necrosis factor alpha (TNF-alpha) and the relationship between liver cell apoptosis and disease severity. A significant increase in liver cell apoptosis was seen in liver sections with increasing grade of steatosis (r = 0.42; P <.0001). Hepatic steatosis and previous heavy alcohol consumption were the only two variables independently associated with the apoptotic index. Increasing steatosis was associated with decreased Bcl-2 mRNA levels and an increase in the proapoptotic Bax/Bcl-2 ratio (r = -0.32, P =.007; and r = 0.27, P =.02, respectively). In the absence of steatosis, increased liver cell apoptosis was not associated with stellate cell activation or fibrosis (r = 0.26, P =.11; r = 0.06, P =.71, respectively). In contrast, in the presence of steatosis, increasing apoptosis was associated with activation of stellate cells and increased stage of fibrosis (r = 0.35, P =.047; r = 0.33, P =.03, respectively), supporting the premise that the steatotic liver is more vulnerable to liver injury. In patients with hepatitis C virus genotype 3, there was a significant correlation between TNF-alpha mRNA levels and active caspase-3 (r = 0.54, P =.007). In conclusion, these observations suggest a mechanism whereby steatosis contributes to the progression of liver injury in chronic hepatitis C. Further investigation will be required to determine the molecular pathways responsible for the proapoptotic effect of steatosis and whether this increase in apoptosis contributes directly to fibrogenesis.     

Steatosis accelerates the progression of liver damage of chronic hepatitis C patients and correlates with specific HCV genotype and visceral obesity

The role of steatosis in the progression of liver damage in chronic hepatitis C (CHC) was studied. Enrolled were 180 consecutive liver biopsy-proven CHC patients and 41 additional subjects with a known duration of infection. We evaluated the histological activity index (HAI), grade of fibrosis and steatosis, body mass index (BMI; kg/m(2)), distribution of body fat, HCV genotype, and levels of HCV RNA. Eighty six (48%) patients showed steatosis, and a higher prevalence was observed in genotype 3a infection (P <.01). A correlation between the grade of steatosis and fibrosis was observed (P <.001). Fibrosis was also associated with age (P <.001). After adjusting for age, the association between steatosis and fibrosis remained significant. The grade of steatosis also correlated with the HAI (P <.007) with a significant increase in periportal necrosis. No relation was found between steatosis and age, gender, iron storage, or levels of HCV RNA. Patients with a high grade of steatosis (>30%) showed higher serum levels of gamma-GT and ALT (P <.001). Overall, steatosis was not significantly associated to BMI. Analysis by single genotype showed a significant association between the grade of steatosis and BMI in type 1 infection r =.689; P <.001) and with levels of HCV RNA in type 3a infection r =.786; P <.001). Visceral fat distribution rather than BMI proved to be associated with steatosis (P <.001). Data obtained from patients with a known date of infection confirmed that steatosis grades 3-4 were associated with a higher annual rate of fibrosis progression, and showed that alcohol and steatosis act together in increasing fibrosis (P <.05). Our data indicate that steatosis is an important cofactor in increasing liver necroinflammatory activity and in accelerating fibrosis in CHC. Visceral obesity and genotype 3a play a role in the development of steatosis.