Impact of hepatic steatosis on viral kinetics and treatment outcome during antiviral treatment of chronic HCV infection

The relation of 25-hydroxy vitamin D concentrations to liver histopathology, seasonality and baseline characteristics in chronic hepatitis C virus genotype 2 or 3 infection

Background and objectives

The hydroxylation to 25-hydroxy vitamin D (25(OH)D) occurs in the liver and the impact of liver disease on vitamin D is unclear. This study evaluated the relationship between vitamin D concentrations and hepatic histopathology, seasonality and patient characteristics in well-characterized patients having undergone a liver biopsy.

Method

25(OH)D was measured post-hoc in pre-treatment serum from 331 North European patients with chronic HCV genotype 2 or 3 infection (NORDynamIC study). Liver biopsies were scored for fibrosis and inflammation according to the Ishak protocol, and graded for steatosis. Non-invasive markers of hepatic fibrosis as well as baseline viral and host characteristics, including genetic polymorphisms rs2228570, rs7975232, and rs10877012 were also evaluated.

Results

Mean 25(OH)D concentration was 59 ±23 nmol/L, with 41% having values <50 nmol/L and 6% were <30 nmol/L. 25(OH)D correlated with fibrosis (r = -0.10, p ≤0.05) in univariate but not in multivariate analyses. No association was observed between 25(OH)D and hepatic inflammation, but with steatosis in HCV genotype 2 infected patients. None of the genetic polymorphisms impacted on 25(OH)D levels or fibrosis. 25(OH)D levels were significantly inversely correlated to BMI (r = -0.19, p = 0.001), and was also associated with season and non-Caucasian ethnicity.

Conclusion

Fibrosis was not independently associated with 25(OH)D concentration and no association was seen with hepatic inflammation, but HCV genotype 2 infected patients with moderate-to-severe steatosis had lower 25(OH)D levels compared to those without steatosis. A high percentage had potential risk of 25(OH)D deficiency, and BMI, seasonality and ethnicity were independently associated with 25(OH)D as previously reported.

Identification of potential anti-hepatitis C virus agents targeting non structural protein 5B using computational techniques

Hepatitis C virus (HCV) nonstructural protein 5B (NS5B) is an RNA-dependent RNA polymerase that plays a key role in HCV replication, and, hence, NS5B is an attractive target for hepatitis C drug discovery. Hepatitis C is a chronic liver disease affecting the global population significantly. Many NS5B inhibitors targeting active site were launched in recent years, however, still there exists a pressing need for cost-effective therapies with pan genotypic activity and therapies targeting niche HCV population with comorbities and resistant to earlier therapies. The objective of the current study is to identify potential anti-HCV agents from FDA approved drugs that are already in the market for a different disease-Drug repurposing approach. A combination of computational chemistry and computational biology techniques was used to discover potential therapies for hepatitis C targeting the NS5B Thumb I allosteric site. Computational chemistry analysis emphasized the fact that fluvastatin, a lipid lowering agent, and olopatadine, an antihistamine, exhibited good binding affinity to NS5B. In addition, gene set enrichment analysis brought to light the significant overlap between disease characteristic features and the mechanism of action of fluvastatin and olopatadine. The current study concludes the potentially beneficial use of fluvastatin in niche hepatitis C patient population suffering from nonalcoholic fatty liver diseases.

Viral and host factors associated with outcomes of hepatitis C virus infection (Review)

Hepatitis C virus (HCV) infection is a major health issue globally. Owing to the progress made in host genetics and HCV molecular virology, emerging data have suggested that the natural course and treatment response in patients with HCV infection are largely determined by complex host‑viral interactions. HCV genotype is the most important viral factor predicting the response to pegylated interferon‑α plus ribavirin therapy. The subtype of HCV genotype 1 is the key viral factor that predicts the efficacy of direct‑acting antiviral therapy. HCV genome heterogeneity and baseline viral load are additionally associated with the treatment response. Multiple host genetic variants localized in genes associated with the immune response have been identified as predictors of spontaneous disease course and therapy outcome in chronic HCV. However, most findings from candidate gene association studies have not been proven universal for all investigated populations and independent studies. Previous findings in independent large genome wide association studies confirmed that interferon‑λ3 gene polymorphisms are associated with spontaneous clearance and treatment responsiveness. A polymorphism of the inosine triphosphatase gene has been identified as a protective factor against ribavirin‑induced anemia and dose reductions. Another genetic variant in the patatin‑like phospholipase domain containing 3 genes is associated with hepatic steatosis and fibrosis in patients with HCV. The present review focused on the identified viral and host factors associated with outcomes of patients with HCV, and assessed the involvement of viral and host genetics in the natural history and treatment outcomes of HCV infection. This will provide novel ideas concerning personalized prevention and individualized clinical management.

Liver steatosis in children with chronic hepatitis B and C: Prevalence, predictors, and impact on disease progression

Only scarce data on liver steatosis in children with chronic hepatitis B and C (CHB and CHC) are available. The objective of this study was to evaluate the prevalence, predictors, and impact of hepatic steatosis on children with CHB and CHC. A total of 78 patients aged 11.5 ± 3.4 years were included: 30 (38%) had CHB, and 48 (62%) had CHC. Steatosis was scored on a 5-point scale, as follows: absent; minimal (≤5% hepatocytes affected), mild (6-33%), moderate (34-66%), and severe (>66%). Stepwise logistic regression was used to determine the factors associated with steatosis and moderate-to-severe steatosis. Steatosis was observed in 4/30 (13%) patients with CHB and 13/48 (27%) patients with CHC (P = 0.17). Moderate-to-severe steatosis was observed in 6/78 (8%) patients: 1/30 (3%) had CHB and 5/48 (10%) had CHC (P = 0.40). The body mass index (BMI) z-score was positively associated with the presence of steatosis in children with CHB (odds ratio [OR] = 3.3, 95% confidence interval [CI]: 1.02-10.64). In CHC, steatosis occurred more frequently in patients with hepatitis C virus genotype 3 compared with other genotypes (P = 0.002). In patients with non-3 genotype hepatitis C virus, steatosis was associated with the stage of fibrosis (OR = 3.35, 95% CI: 1.01-11.07) and inversely associated with the duration of infection (OR = 0.74, 95% CI: 0.55-0.97). Moderate-to-severe steatosis was positively associated with the BMI z-score (OR = 3.62, 95% CI: 1.22-10.75) and stage of fibrosis (OR = 3.89, 95% CI: 1.05-14.47). Steatosis is a common finding in children with chronic viral hepatitis. It is associated with metabolic factors in CHB, whereas in patients with CHC, metabolic and viral factors may have a combined effect, leading to more advanced grades of steatosis in children with higher BMI z-scores. Moderate-to-severe steatosis is a predictor of advanced fibrosis in children with CHC.

NAFLD and NASH in HCV Infection: Prevalence and Significance in Hepatic and Extrahepatic Manifestations

The aim of this paper is to review and up to date the prevalence of hepatitis C virus (HCV)-associated non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) and their significance in both accelerating progression of HCV-related liver disease and development of HCV-associated extrahepatic diseases. The reported mean prevalence of HCV-related NAFLD was 55%, whereas NASH was reported in 4%–10% of cases. HCV genotype 3 directly induces fatty liver deposition, namely “viral steatosis” and it is associated with the highest prevalence and degree of severity, whereas, HCV non-3 genotype infection showed lower prevalence of steatosis, which is associated with metabolic factors and insulin resistance. The host’s genetic background predisposes him or her to the development of steatosis. HCV’s impairment of lipid and glucose metabolism causes fatty liver accumulation; this seems to be a viral strategy to optimize its life cycle. Irrespective of insulin resistance, HCV-associated NAFLD, in a degree-dependent manner, contributes towards accelerating the liver fibrosis progression and development of hepatocellular carcinoma by inducing liver inflammation and oxidative stress. Furthermore, NAFLD is associated with the presence of metabolic syndrome, type 2 diabetes, and atherosclerosis. In addition, HCV-related “metabolic steatosis” impairs the response rate to interferon-based treatment, whereas it seems that “viral steatosis” may harm the response rate to new oral direct antiviral agents. In conclusion, a high prevalence of NAFLD occurs in HCV infections, which is, at least in part, induced by the virus, and that NAFLD significantly impacts progression of the liver disease, therapeutic response, and some extrahepatic diseases.

Coadministration of ezetimibe with pegylated interferon plus ribavirin could improve early virological response in chronic hepatitis C obese Egyptian patients

BACKGROUND

Ezetimibe has been reported to inhibit viral entry and to reduce BMI and has been proposed as a novel therapeutic agent for chronic hepatitis C (CHC), potentiating the effects of pegylated interferon and ribavirin (peg-IFN/RBV).

OBJECTIVE

The aim of the study was to assess the effects of ezetimibe coadministration with peg-IFN/RBV combination on the early virological response (EVR) rates in nonobese and obese patients with CHC genotype 4 (CHC-4).

PATIENTS AND METHODS

A total of 144 CHC-4 patients were divided into two groups; group 1 included nonobese patients (n=76) and group 2 included obese patients (n=68). Each group was further subclassified into equal control and treated groups. The control groups received peg-IFN/RBV combination for 24 weeks, and the treated groups received peg-IFN/RBV plus ezetimibe for 12 weeks and then only peg-IFN/RBV for the remaining 12 weeks.

RESULTS

The study revealed that EVR significantly improved in the obese patients (85.3 vs. 64.7% in the treated and control groups, respectively, at P<0.05) without any significant improvement in the nonobese patients. Biochemical responses (defined as normalization of alanine aminotransferase at week 12) were markedly improved in the treated groups in both the nonobese and obese groups compared with their respective controls.

CONCLUSION

The addition of ezetimibe to peg-IFN/RBV combination significantly improves EVR rates in obese patients compared with nonobese patients, and remarkably improves the biochemical responses in both obese and nonobese patients with CHC-4. This may shed light on a new strategy for the treatment of CHC, particularly in obese Egyptian patients.

Nonalcoholic fatty liver disease and hepatic cirrhosis: Comparison with viral hepatitis-associated steatosis

Nonalcoholic fatty liver disease (NAFLD) including nonalcoholic steatohepatitis (NASH) is globally increasing and has become a world-wide health problem. Chronic infection with hepatitis B virus or hepatitis C virus (HCV) is associated with hepatic steatosis. Viral hepatitis-associated hepatic steatosis is often caused by metabolic syndrome including obesity, type 2 diabetes mellitus and/or dyslipidemia. It has been reported that HCV genotype 3 exerts direct metabolic effects that lead to hepatic steatosis. In this review, the differences between NAFLD/NASH and viral hepatitis-associated steatosis are discussed.

Lipid profile and hepatic steatosis in hepatitis C infected egyptian survivors of childhood cancer

BACKGOUND/AIM

Studies associating chronic hepatitis C virus (HCV) infection with lipid profile and hepatic steatosis in children and adolescents are scarce. This study investigated lipid profile abnormalities and hepatic steatosis among HCV-infected Egyptian children and adolescents who survived leukemia and lymphoma and evaluated impact on response to antiviral therapy.

SUBJECTS AND METHODS

Thirty-six leukemia/lymphoma cured children and adolescents (mean age: 12.47 ± 3.56 years) with chronic HCV infection and 30 healthy controls (mean age: 11.64 ± 3.96 years) were enrolled in this prospective study. Serum lipid profile and abdominal ultrasonography were done for all patients and controls. Guided liver biopsy with histopathological examination was done for 32 (88.9%) patients eligible for antiviral therapy.

RESULTS

Total cholesterol, LDL-cholesterol, and apolipoprotein B (apo-B) in patients were significantly lower than in the control group (P ≤ .01, ≤ .01, and ≤ .05, respectively). Among those who underwent liver biopsy (n = 32), macrovesicular hepatic steatosis associated with chronic hepatitis C was documented in 10 children (31.3%). Body mass index was significantly higher (P ≤ .05) and apo-B was significantly lower in steatotic (P ≤ .05) than non-steatotic HCV-infected children. Liver span by ultrasound, alanine aminotransferase (ALT), and apo-B were independent predictors for hepatic steatosis (P < .001, <.001, and <.05, respectively). A significantly worse response to interferon alpha 2-b plus ribavrin treatment for HCV was reported among children with steatosis (P < .001).

CONCLUSIONS

The study showed low serum lipids in HCV-infected children with cured leukemia/lymphoma. Hepatic steatosis was found in a significant proportion of patients and was associated with a poor response to antiviral treatment.

Fatty Acids Induce a Pro-Inflammatory Gene Expression Profile in Huh-7 Cells That Attenuates the Anti-HCV Action of Interferon

The pathogenesis of nonalcoholic steatohepatitis is primarily an immune-driven disease and a known factor associated with treatment failure of chronic hepatitis C with interferon (IFN) and ribavirin. We studied the hepatocyte response in a model of steatosis at the transcriptome level and the antiviral action of IFN against hepatitis C virus (HCV) in this setting. In this study, we have shown that lipid loading (oleic acid and palmitic acid, OA:PA) of Huh-7 cells leads to increased expression of classical interferon-stimulated genes (ISGs) and NF-κβ-dependent pro-inflammatory genes. A selective blocker of Toll-like receptor (TLR)2 signaling suppressed NF-κβ promoter activity by OA:PA, suggesting that free fatty acids (FFAs) act as a TLR2 pathogen-associated molecular pattern. Furthermore, in the presence of OA:PA, IFN stimulation and HCV infection (Jc1) increased ISG expression. Somewhat counterintuitive to the increase in ISGs, the anti-HCV activity of IFN was attenuated in the presence of OA:PA. Interestingly, the combination of OA:PA, HCV, and IFN-α stimulation resulted in a significant increase in CXCL8 protein production, a cytokine known to have anti-IFN modulating activity. Thus, in an in vitro model of steatosis, the FFAs OA and PA drive an NF-κβ-dependent inflammatory and ISG gene expression profile via TLR2 activation. Furthermore, FFA synergistically increases IFN-driven gene expression that may account for HCV treatment failure in vivo.

Influence of hepatitis C virus and IL28B genotypes on liver stiffness

OBJECTIVE

Liver fibrosis has been associated with hepatitis C virus (HCV) genotype and genetic variation near the interleukin 28B (IL28B) gene, but the relative contribution is unknown. We aimed to investigate the relation between HCV genotypes, IL28B and development of liver stiffness.

PATIENTS AND METHODS

This cross-sectional study consists of 369 patients with chronic hepatitis C (CHC). Liver stiffness was evaluated using transient elastograhy (TE). Factors associated with development of liver fibrosis were identified by logistic regression analysis.

RESULTS

We identified 369 patients with CHC. 235 were male, 297 Caucasians, and 223 had been exposed to HCV through intravenous drug use. The overall median TE value was 7.4 kPa (interquartile range (IQR) 5.7-12.1). HCV replication was enhanced in patients carrying the IL28B CC genotype compared to TT and TC (5.8 vs. 5.4 log10 IU/mL, p = 0.03). Patients infected with HCV genotype 3 had significantly higher TE values (8.2 kPa; IQR, 5.9-14.5) compared to genotype 1 (6.9 kPa; IQR, 5.4-10.9) and 2 (6.7 kPa; IQR, 4.9-8.8) (p = 0.02). Within patients with genotype 3, IL28B CC genotype had the highest TE values (p = 0.04). However, in multivariate logistic regression, using various cut-off values for fibrosis and cirrhosis, only increasing age (odds ratio (OR) 1.09 (95% confidence interval (CI), 1.05-1.14 per year increment)), ALT (OR 1.01 (95% CI, 1.002-1.011), per unit increment) and HCV genotype 3 compared to genotype 1 (OR 2.40 (95% CI, 1.19-4.81), were consistently associated with cirrhosis (TE>17.1 kPa).

CONCLUSIONS

Age, ALT and infection with HCV genotype 3 were associated with cirrhosis assessed by TE. However, IL28B genotype was not an independent predictor of fibrosis in our study.

Consensus Statement of HCV Task Force of the Indian National Association for Study of the Liver (INASL). Part II: INASL Recommendations for Management of HCV in India

The estimated prevalence of hepatitis C virus (HCV) infection in India is between 0.5 and 1.5% with hotspots showing much higher prevalence in some areas of northeast India, in some tribal populations and in certain parts of Punjab. Genotype 3 is the most prevalent type of infection. Recent years have seen development of a large number of new molecules that are revolutionizing the treatment of hepatitis C. Some of the new directly acting agents (DAAs) like sofosbuvir have been called game-changers because they offer the prospect of interferon-free regimens for the treatment of HCV infection. These new drugs have not yet been approved in India and their cost and availability is uncertain at present. Till these drugs become available at an affordable cost, the treatment that was standard of care for the whole world before these newer drugs were approved should continue to be recommended. For India, cheaper options, which are as effective as the standard-of-care (SOC) in carefully selected patients, are also explored to bring treatment within reach of poorer patients. It may be prudent to withhold treatment at present for selected patients with genotype 1 or 4 infection and low levels of fibrosis (F1 or F2), and for patients who are non-responders to initial therapy, interferon intolerant, those with decompensated liver disease, and patients in special populations such as stable patients after liver and kidney transplantation, HIV co-infected patients and those with cirrhosis of liver.

Hepatitis C and lipid metabolism, hepatic steatosis, and NAFLD: still important in the era of direct acting antiviral therapy?

Chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) have an individual prevalence of 1.8-3% and at least 30%, respectively, in the United States. It is therefore not surprising that there is overlap between these two common chronic liver diseases, although the relationship appears to go beyond isolated co-existence. Hepatic steatosis is a common feature of CHC infection and can be related to both metabolic and viral specific factors. Steatosis in the setting of nongenotype 3 CHC has been predictive of response to therapy prior to the advent of the direct acting antiviral medications (DAAs). Similarly, lipid metabolism appears important in response to CHC treatment. The pathways for both lipid homeostasis and NAFLD as it pertains to CHC infection as well as the utilization of statin therapy in CHC infection will be reviewed with a focus on the relevance of these topics in the era of DAA therapy.

Antiviral treatment of hepatitis C virus infection and factors affecting efficacy

Hepatitis C virus (HCV) infection is the leading cause of chronic liver-related diseases, including cirrhosis, liver failure, and hepatocellular carcinoma. Currently, no effective vaccine is available for HCV infection. Polyethylene glycol interferon-α (PegIFN-α) in combination with ribavirin (RBV) is the standard of care (SOC) for chronic hepatitis C. However, the efficacy of PegIFN-α and RBV combination therapy is less than 50% for genotype 1 HCV, which is the dominant virus in humans. In addition, IFN and RBV have several severe side effects. Therefore, strategies to improve sustained virological response (SVR) rates have been an important focus for clinical physicians. The serine protease inhibitors telaprevir and boceprevir were approved by the United States Food and Drug Administration in 2011. The addition of HCV protease inhibitors to the SOC has significantly improved the efficacy of treatments for HCV infection. Several direct-acting antiviral drugs currently in late-stage clinical trials, both with and without peg-IFN and RBV, have several advantages over the previous SOC, including higher specificity and efficacy, fewer side effects, and the ability to be administered orally, and might be optimal regimens in the future. Factors affecting the efficacy of anti-HCV treatments based on IFN-α include the HCV genotype, baseline viral load, virological response during treatment, host IL28B gene polymorphisms and hepatic steatosis. However, determining the effect of the above factors on DAA therapy is necessary. In this review, we summarize the development of anti-HCV agents and assess the main factors affecting the efficacy of antiviral treatments.

Insulin resistance in non-diabetic patients of chronic Hepatitis C

Objective: To determine insulin resistance in non-diabetic chronic hepatitis C patients using Homeostatic Model Assessment of Insulin Resistance (HOMA-IR).

Methodology: Patients having anti-HCV positive were included in this study. Patients with diabetes mellitus, thyroid disease, hyperlipidemias, hypercortisolism and infective diseases other than hepatitis C were excluded. Age, weight, height and absence of diabetes were documented. Fasting blood glucose and fasting insulin levels were done. Body mass index and insulin resistance was calculated using the formulas. Patients having insulin resistance using formula HOMA-IR>2.5 were labeled as insulin resistant. Data was analyzed using SPSS-18.

Results: One hundred and fifty five patients according to sample size estimation were enrolled, in whom HOMA-IR was calculated, the mean value was found to be 2.47 ±1.30. A total of 79 (51%) of patients had HOMA-IR more than 2.5 showing insulin resistance.

Conclusion: In a third world country like Pakistan, where there is a high prevalence of hepatitis C infection, the consequences of the disease are also very common. Insulin resistance was found in 51% of patients with chronic hepatitis C.

Impact of Il28b-related single nucleotide polymorphisms on liver transient elastography in chronic hepatitis C infection

BACKGROUND AND AIMS

Recently, several genome-wide association studies have revealed that single nucleotide polymorphisms (SNPs) in proximity to IL28B predict spontaneous clearance of hepatitis C virus (HCV) infection as well as outcome following pegylated interferon and ribavirin therapy among genotype 1 infected patients. Additionally the presence of the otherwise favorable IL28B genetic variants in the context of HCV genotype 3 infection reportedly entail more pronounced liver fibrosis and steatosis. The present study aimed to evaluate the impact of IL28B SNP variability on liver stiffness as accessed by transient elastography.

METHODS

Seven hundred and seventy-one Swedish HCV infected patients sequentially undergoing liver stiffness measurement by means of Fibroscan® in the context of a real-life trial had samples available for IL28B genotyping (rs12979860) and HCV genotyping.

RESULTS

CC(rs12979860) was more common among HCV genotype 2 or 3 infected treatment-naïve patients than among those infected with genotype 1 (P<0.0001). Additionally CC(rs12979860) among HCV genotype 3 infected patients was associated with higher liver stiffness values (P = 0.004), and higher AST to platelet ratio index (APRI; p = 0.02) as compared to carriers of the T allele. Among HCV genotype 1 infected patients, CC(rs12979860) was significantly associated with higher viral load (P = 0.001), with a similar non-significant trend noted among HCV genotype 3 infected patients.

CONCLUSION

This study confirms previous reports that the CC(rs12979860) SNP is associated with more pronounced liver pathology in patients chronically infected with HCV genotype 3 as compared to genotype 1, suggesting that IL28B genetic variants differently regulates the course of HCV infection across HCV genotypes.

Who is more likely to respond to dual treatment with pegylated-interferon and ribavirin for chronic hepatitis C? A gender-oriented analysis

We assessed, in real-life practice, viral, demographic, genetic and metabolic factors influencing the sustained virologic response (SVR), with a gender-oriented analysis, in patients with chronic hepatitis C virus (HCV) treated with pegylated interferon and ribavirin. Six hundred and seventy naïve patients were treated with dual therapy and evaluated by gender and HCV genotype. Associations between baseline variables and SVR were assessed by multivariate logistic regression analysis. Among 362 genotype 1 patients, SVR was achieved in 158 patients (44%), and SVR was independently associated with age less than 50 years (OR 2.12; 95% CI 1.09-4.30; P=0.039) and C/C genotype rs12979860 SNP (OR 2.83; 1.19-6.74; P=0.002) in 163 females, while absence of visceral obesity (OR 2.491; 1.131-5.487; P=0.023), HCV-RNA lower than 400,000 IU/mL (OR 2.66; 1.273-5.558; P=0.009) and C/C genotype rs12979860 SNP (OR 4.969; 2.401-10.283; P<0.001) were independently associated with SVR in 199 males. Combining favourable baseline variables, the probability of obtaining SVR ranged from 27.6% to 84.2% in females, and from 14.3% to 85.7% in males. The rate of SVR was 81.1% in 175 genotype 2 patients, and 69% in 100 genotype 3 patients. Rapid virologic response was the only valid predictor of SVR regardless of other features. In conclusions, in the setting of HCV genotype 1, chronic hepatitis, combining rapid virologic response and predictive factors, which are different for females and males, allows clinicians to single out a group of patients whose likelihood of SVR exceeds 80%. For these patients, triple therapy with first-generation protease inhibitors may be unwarranted.

Hepatitis C virus, cholesterol and lipoproteins--impact for the viral life cycle and pathogenesis of liver disease

Hepatitis C virus (HCV) is a leading cause of chronic liver disease, including chronic hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Hepatitis C infection associates with lipid and lipoprotein metabolism disorders such as hepatic steatosis, hypobetalipoproteinemia, and hypocholesterolemia. Furthermore, virus production is dependent on hepatic very-low-density lipoprotein (VLDL) assembly, and circulating virions are physically associated with lipoproteins in complexes termed lipoviral particles. Evidence has indicated several functional roles for the formation of these complexes, including co-opting of lipoprotein receptors for attachment and entry, concealing epitopes to facilitate immune escape, and hijacking host factors for HCV maturation and secretion. Here, we review the evidence surrounding pathogenesis of the hepatitis C infection regarding lipoprotein engagement, cholesterol and triglyceride regulation, and the molecular mechanisms underlying these effects.

The predictive value of steatosis in hepatitis C virus infection

Steatosis is a complication of hepatitis C virus (HCV) infection and the mechanisms of its development are complex, involving viral and host factors. Steatosis that is prevalently viral is associated with HCV genotype 3, and steatosis that is prevalently metabolic is associated with non-3 genotypes. Viral steatosis is correlated with the level of HCV replication, whereas metabolic steatosis is related to insulin resistance. The two types of steatosis have a different impact on HCV disease and may have an additive effect. HCV infection is a multifaceted disease with hepatic and extrahepatic manifestations. There is a body of evidence indicating that HCV-related steatosis plays a role in many HCV manifestations and, thus, the presence of steatosis is a predictive factor for the development of such events. The current data show that HCV-related steatosis predicts an advanced liver disease and a more rapid progression of fibrosis, as well as an increased risk of development of hepatocellular carcinoma. Moreover, the presence of steatosis in a HCV patient has a high predictive value that the subject may have or may develop insulin resistance, diabetes and metabolic syndrome. Recently, a strict association between HCV-related steatosis and development of atherosclerosis has been demonstrated. In addition, steatosis negatively impacts response rate to interferon-based treatment, even in HCV genotype-3 infection. Therapeutic strategies to improve steatosis and, consequently, response to standard antiviral therapy and outcome of disease are wanted. The authors summarize current knowledge of impact of steatosis on the above reported clinical conditions associated with HCV infection.

PNPLA 3 I148M genetic variant associates with insulin resistance and baseline viral load in HCV genotype 2 but not in genotype 3 infection

Background

Hepatic steatosis in HCV patients has been postulated as a risk factor associated with a higher frequency of fibrosis and cirrhosis. A single genetic variant, PNPLA3 I148M, has been widely associated with increased hepatic steatosis. Previous studies of the PNPLA3 I148M sequence variant in HCV infected individuals have reported an association between this variant and prevalence of steatosis, fibrosis, and cirrhosis. To evaluate the impact of PNPLA3 I148M variant on metabolic traits and treatment response in HCV genotype 2 and 3 infected patients.

Methods

Three hundred and eighty-two treatment naïve HCV genotype 2 or 3 infected patients were included in a phase III, open label, randomized, multicenter, investigator-initiated trial (the NORDynamIC study), in which pretreatment liver biopsies were mandatory. PNPLA3I148M genotyping was performed in a total of 359 Caucasian patients.

Results

In HCV genotype 2 infected patients carrying the PNPLA3 148M allele, there was significantly increased insulin resistance (P = 0.023) and lower viral load (P = 0.005) at baseline as well as the first seven days of antiviral treatment. These results were not observed in HCV genotype 3 infected patients.

Conclusions

Our results suggest a possible association between the PNPLA3 148M allele and insulin resistance as well as baseline viral load in HCV genotype 2, but not in genotype 3.

Factors influencing rapid and early virological response to interferon therapy in patients with chronic hepatitis C

AIM: To investigate the predictive factors associated with rapid and early virological response to pegylated interferon and ribavirin treatment in patients with chronic hepatitis C to provide the basis for treatment selection and outcome prediction of antiviral therapy.

METHODS: Eighty-one patients with chronic hepatitis C treated with pegylated interferon and ribavirin were followed up at 4, 12, 24, 48 wk and at least 24 wk after discontinuing treatment. Information for the patients was recorded in detail, including sex, age, baseline HCVRNA level, body mass index (BMI), diabetes mellitus, cirrhosis, history of alcohol consumption, fatty liver, blood transfusion history, and previous antiviral treatment history. Patients were divided into rapid virological response (RVR) group, early virological response (EVR) group, no response (NR) group, relapse (RL) group, and sustained virological response (SVR) group according to the treatment situation. Univariate analysis and multivariate logistic stepwise regression analysis were used to analyze the influencing and predicting factors of RVR and EVR.

RESULTS: Of 81 patients, 51 achieved RVR, 65 achieved EVR, 65 achieved SVR, 10 had NR, and 6 had RL. The rates of RVR, EVR, SVR, NR and RL were 62.9%, 80.2%, 80.2%, 12.3% and 7.4%, respectively. In the RVR group, 88.2% of the cases achieved SVR, while in the EVR group the rate of SVR was 90.8%. Sixteen cases (19.8%) did not achieve RVR and EVR, and 6 of them (37.5%) achieved SVR and had no recurrence. The SVR rates were significantly different among the RVR, EVR, and non-RVR/EVR groups (χ² = 20.622, P < 0.05), but the RL rate had no significant difference among them. The rates of RVR and EVR among the SVR, NR and RL groups were significantly different. Univariate analysis showed that RVR was associated with age ≤ 40 years old, HCV RNA < 4 × 10⁵ IU/mL, and no cirrhosis, while EVR was associated with age ≤ 40 years old, HCV RNA < 4 × 10⁵ IU/mL, no cirrhosis, and BMI < 24 kg/m². Multivariate logistic stepwise regression analysis showed that baseline HCV RNA load and cirrhosis were independent factors for predicting RVR and EVR.

CONCLUSION: The acquisition of RVR and EVR is a significant predictor of SVR. In non-RVR and non-EVR groups, a minority of patients still could achieve SVR after one year of treatment. RVR and EVR can not predict recurrence. Predicting factors including age, baseline viral load, liver cirrhosis, and body mass index are closely related to RVR and EVR. Baseline viral load and liver cirrhosis are independent predictive factors for RVR and EVR.

Free fatty acids induce ER stress and block antiviral activity of interferon alpha against hepatitis C virus in cell culture

Background

Hepatic steatosis is recognized as a major risk factor for liver disease progression and impaired response to interferon based therapy in chronic hepatitis C (CHC) patients. The mechanism of response to interferon-alpha (IFN-α) therapy under the condition of hepatic steatosis is unexplored. We investigated the effect of hepatocellular steatosis on hepatitis C virus (HCV) replication and IFN-α antiviral response in a cell culture model.

Methods

Sub-genomic replicon (S3-GFP) and HCV infected Huh-7.5 cells were cultured with a mixture of saturated (palmitate) and unsaturated (oleate) long-chain free fatty acids (FFA). Intracytoplasmic fat accumulation in these cells was visualized by Nile red staining and electron microscopy then quantified by microfluorometry. The effect of FFA treatment on HCV replication and IFN-α antiviral response was measured by flow cytometric analysis, Renilla luciferase activity, and real-time RT-PCR.

Results

FFA treatment induced dose dependent hepatocellular steatosis and lipid droplet accumulation in the HCV replicon cells was confirmed by Nile red staining, microfluorometry, and by electron microscopy. Intracellular fat accumulation supports replication more in the persistently HCV infected culture than in the sub-genomic replicon (S3-GFP) cell line. FFA treatment also partially blocked IFN-α response and viral clearance by reducing the phosphorylation of Stat1 and Stat2 dependent IFN-β promoter activation. We show that FFA treatment induces endoplasmic reticulum (ER) stress response and down regulates the IFNAR1 chain of the type I IFN receptor leading to defective Jak-Stat signaling and impaired antiviral response.

Conclusion

These results suggest that intracellular fat accumulation in HCV cell culture induces ER stress, defective Jak-Stat signaling, and attenuates the antiviral response, thus providing an explanation to the clinical observation regarding how hepatocellular steatosis influences IFN-α response in CHC.

The impact of fibrosis and steatosis on early viral kinetics in HCV genotype 1-infected patients treated with Peg-IFN-alfa-2a and ribavirin

Hepatitis C viral (HCV) kinetics after initiation of interferon-based therapy provide valuable insights for understanding virus pathogenesis, evaluating treatment antiviral effectiveness and predicting treatment outcome. Adverse effects of liver fibrosis and steatosis on sustained virological response have been frequently reported, yet their impacts on the early viral kinetics remain unclear. In this study, associations between histology status and early viral kinetics were assessed in 149 HCV genotype 1-infected patients treated with pegylated interferon alfa-2a and ribavirin (DITTO trial). In multivariate analyses adjusted for critical factors such as IL28B genotype and baseline viral load, presence of significant fibrosis (Ishak stage > 2) was found to independently reduce the odds of achieving an initial reduction (calculated from day 0 to day 4) in HCV RNA of ≥2 logIU/mL (adjusted OR 0.03, P = 0.004) but was not associated with the second-phase slope of viral decline (calculated from day 8 to day 29). On the contrary, presence of liver steatosis was an independent risk factor for not having a rapid second-phase slope, that is, ≥0.3 logIU/mL/week (adjusted OR 0.22, P = 0.012) but was not associated with the first-phase decline. Viral kinetic modelling theory suggests that significant fibrosis primarily impairs the treatment antiviral effectiveness in blocking viral production by infected cells, whereas the presence of steatosis is associated with a lower net loss of infected cells. Further studies will be necessary to identify the biological mechanisms underlain by these findings.

Impact of obesity on the bioavailability of peginterferon-α2a and ribavirin and treatment outcome for chronic hepatitis C genotype 2 or 3

Background and Aims

Having a body mass index above or equal to 30 kg/m² in conjunction with chronic hepatitis C virus infection is associated with non-responsiveness to treatment with interferon and ribavirin, but details regarding the mechanisms whereby obesity reduces the efficacy of therapy remain unclear.

Methods

This study evaluated impact of obesity on outcome as well as interferon and ribavirin concentrations following standard-of-care fixed dosing with peginterferon-α2a 180 µg once weekly and ribavirin 800 mg daily among 303 HCV genotype 2/3-infected patients enrolled in the per-protocol analysis of a recently completed phase III trial (NORDynamIC).

Results

Patients with BMI ≥30 kg/m² showed poorer outcome following 24 weeks of therapy (SVR 62% vs. 89% for BMI ≥30 vs. <30; P = 0.006) along with significantly higher steatosis grade (P = 0.002), HOMA-IR (P<0.0001), triglyceride levels (P = 0.0002), and baseline viral load (P = 0.028). Obesity was also significantly associated with lower plasma interferon concentrations on days 3, 7, and 29 (P = 0.02, P = 0.0017, and P<0.0001, respectively) and lower plasma ribavirin concentrations day 29 (P = 0.025), and lower concentration of interferon in turn was associated with a poorer first phase reduction in HCV RNA (P<0.0001). In multivariate analysis, ribavirin concentrations week 12, interferon concentrations day 29, and baseline HCV RNA levels were independent predictors of achieving SVR among patients treated for 24 weeks (n = 140).

Conclusions

Reduced bioavailability of interferon and ribavirin along with higher baseline viral load are dominant risk factors for treatment failure in obese patients with chronic hepatitis C.

Impact of IL28B-related single nucleotide polymorphisms on liver histopathology in chronic hepatitis C genotype 2 and 3

BACKGROUND AND AIMS

Recently, several genome-wide association studies have revealed that single nucleotide polymorphisms (SNPs) in proximity to IL28B predict spontaneous clearance of HCV infection as well as outcome following peginterferon and ribavirin therapy among HCV genotype 1 infected patients. The present study aimed to evaluate the impact of IL28B SNP variability on liver histology in the context of a phase III treatment trial (NORDynamIC) for treatment-naïve patients with chronic HCV genotype 2 or 3 infection, where pretreatment liver biopsies were mandatory.

METHODS

Three hundred and thirty-nine Caucasian patients had samples available for IL28B genotyping (rs12979860) of whom 314 had pretreatment liver biopsies that were evaluated using the Ishak protocol, allowing for detailed grading and staging of liver histopathology.

RESULTS

IL28B CC(rs12979860) genotype in HCV genotype 3 infected patients was associated with higher ALT levels (p<0.0001), higher AST to platelet ratio index (APRI; p = 0.001), and higher baseline viral load (p<0.0001) as compared to patients with the CT or TT genotypes. Additionally the CC(rs12979860) genotype entailed more pronounced portal inflammation (p = 0.02) and steatosis (p = 0.03). None of these associations were noted among HCV genotype 2 infected patients.

CONCLUSION

This study shows that the CC(rs12979860) SNP is associated with more pronounced liver histopathology in patients chronically infected with HCV genotype 3, which may be secondary to higher viral load. The finding that IL28B variability did not impact on liver pathology or viral load among genotype 2 infected patients implies that IL28B may differentially regulate the course of genotype 2 and 3 infection.

Rescue therapy for lamivudine-resistant chronic hepatitis B: adefovir monotherapy, adefovir plus lamivudine or entecavir combination therapy

OBJECTIVE

We aimed to compare the cumulative efficacy and resistance of ADV monotherapy, ADV add-on LAM (ADV + LAM), ADV and ETV (ADV + ETV) combination therapy in LAM-resistant patients.

METHODS

Ninety-one adult CHB patients with LAM-resistance mutations (YMDD) were identified. Of these 91, 29 patients were treated with ADV monotherapy, 30 were treated with ADV + LAM and 32 were treated with ADV + ETV combination therapy, for at least 24 months.

RESULTS

The mean serum HBV-DNA decreases from baseline at 3, 6, 12, and 24 months were -3.23, -4.41, -5.32, and -5.58 log(10) IU/mL in the ADV + ETV combination therapy groups, respectively; the most significant among the three treatment groups (p<0.01). The rate of HBV-DNA PCR undetectability (<60 IU/mL) at 6 months in ADV + ETV combination therapy was 78.1%; also the most significant among the three treatment groups (p=0.024). Viral breakthrough and genotypic mutations were detected in 8 (27.6%) and 4 (13.3%) patients in the ADV monotherapy and ADV+LAM therapy groups, respectively; whereas no case of viral breakthrough and genotypic resistance was detected in the ADV+ETV combination therapy group after 24 months (p<0.05).

CONCLUSION

ADV + ETV combination therapy demonstrated faster and significantly greater suppression of HBV DNA compared with ADV add-on LAM combination therapy for patients with LAM-resistance mutations. ADV + ETV was superior to ADV + LAM in achieving initial virological response and long-term suppression activity against HBV. ADV + ETV combination therapy was the most effective to refrain from selecting HBV strains with cross-resistance to three NAs (LAM, ADV and ETV) for LAM-resistance patients.

Steatosis and insulin resistance in response to treatment of chronic hepatitis C

This review will focus on the impact of steatosis and insulin resistance on the response to antiviral therapy for chronic hepatitis C. Hepatitis C virus (HCV) infection is known to have direct and/or indirect effects on lipid and glucose metabolism, leading to, among other disturbances, steatosis and insulin resistance, respectively. Some of these disturbances have a marked HCV genotype distribution. For example, on average, patients with HCV genotype 3 have the highest prevalence and severity of viral fatty liver. On the other hand, the current global spread of the metabolic syndrome represents a formidable cofactor of morbidity in HCV-related chronic liver disease. Thus, the pathogenesis of steatosis and insulin resistance in patients with chronic hepatitis C may often be dual, i.e. viral and metabolic. This distinction is relevant because the effect (if any) of steatosis or insulin resistance on the response to antiviral agents seems to depend on their pathogenesis. Accumulating data suggest that viral fatty liver may not impact on response to therapy, while metabolic steatosis does. Similarly, viral insulin resistance may not reduce the rate of response to therapy to the same extent that metabolic insulin resistance does. Some implications for patient management are discussed.

The role of bile acid retention and a common polymorphism in the ABCB11 gene as host factors affecting antiviral treatment response in chronic hepatitis C

The outcome of hepatitis C virus (HCV) infection and the likelihood of a sustained virological response (SVR) to antiviral therapy depends on both viral and host characteristics. In vitro studies demonstrated that bile acids (BA) interfere with antiviral interferon effects. We investigate the influence of plasma BA concentrations and an ABCB11 polymorphism associated with lower transporter expression on viral load and SVR. Four hundred and fifty-one Caucasian HCV-patients treated with PEG-interferon and ribavirin were included in the study. ABCB11 1331T>C was genotyped, and plasma BA levels were determined. The 1331C allele was slightly overrepresented in HCV-patients compared to controls. In HCV-patients, a significant difference between patients achieving SVR vs non-SVR was observed for HCV-2/3 (5 vs 9 μm; P=0.0001), while median BA levels in HCV-1 were marginally elevated. Normal BA levels <8 μm were significantly associated with SVR (58.3%vs 36.3%; OR 2.48; P=0.0001). This difference was significant for HCV-2/3 (90.7%vs 67.6%; P=0.002) but marginal in HCV-1 (38.7%vs 27.8%; P=0.058). SVR rates were equivalent between ABCB11 genotypes for HCV-1, but increased for HCV-2/3 (TT 100%vs CC 78%; OR 2.01; P=0.043). IL28B genotype had no influence on these associations. No correlation between BA levels and HCV RNA was detected for any HCV genotype. The higher allelic frequency of ABCB11 1331C in HCV-patients compared to controls may indirectly link increased BA to HCV chronicity. Our data support a role for BA as host factor affecting therapy response in HCV-2/3 patients, whereas a weaker association was found for HCV-1.

Analysis of the sustained virological response in patients with chronic hepatitis C and liver steatosis

CONTEXT

Chronic hepatitis C as well as non-alcoholic fatty liver disease are recognized as the main cause of liver disease in Western countries. It is common to see the concomitance of the diseases and the influence of steatosis in the sustained virological response of patients with hepatitis C virus.

OBJECTIVE

Assess the sustained virological response in chronic hepatitis C patients according to the presence of liver steatosis.

METHODS

One hundred sixty patients with chronic hepatitis C were retrospectively evaluated. Demographic data such as gender, age, body mass index, presence of diabetes mellitus and systemic arterial hypertension, virus genotype and use of pegylated interferon were analyzed, as was the staging of fibrosis and the presence of steatosis at histology.

RESULTS

Most patients were male (57.5%), with a mean age of 48 ± 9.7 years. The most frequent genotype observed was 3 (56.9%) and, in the histological evaluation, steatosis was observed in 65% of the patients (104/160). Sustained virological response in patients with steatosis occurred in 38.5%, and in 32.1% in patients without steatosis (P = 0.54). When we analyzed possible factors associated with the presence of steatosis, only body mass index and systemic arterial hypertension revealed a significant association. When the factors that influenced sustained virological response were evaluated in a logistic regression, genotype and use of pegylated interferon proved to be independent factors associated to the response.

CONCLUSION

In the evaluated patients the presence of liver steatosis did not influence the sustained virological response of patients with chronic hepatitis C treated with interferon and ribavirin.

Metabolic alterations and chronic hepatitis C: treatment strategies

INTRODUCTION

Chronic hepatitis C (HCV) infection is considered a metabolic disease. It is associated with a specific metabolic syndrome, HCV-associated dysmetabolic syndrome (HCADS), consisting of steatosis, hypocholesterolemia and insulin resistance/diabetes. These metabolic derangements contribute to a decrease in sustained virological response (SVR) to pegylated-interferon-α-ribavirin as standard of care (SOC), and are associated with progression of liver fibrosis.

AREAS COVERED

The review, highlighting the impact of HCADS and metabolic syndrome components of HCV disease progression and SOC, discusses current knowledge and perspectives on metabolic therapeutic strategies aimed at improving SVR rate of SOC for chronic hepatitis C.

EXPERT OPINION

HCV, features of HCADS and of metabolic syndrome may coexist in the same patient, thus all components of the metabolic syndrome must be assessed to individualize treatment. The results of therapeutic trials evaluating metabolic strategies combined with current SOC indicate that weight loss is a critical part of treatment which will improve both disease outcome and therapeutic response to SOC. Similarly, statins seem to improve response rate to SOC representing, once confirmed to be safe, an important therapeutic tool for HCV-infected patients. Findings from studies using insulin sensitizers combined with SOC are not conclusive and do not justify the use of this class of drugs in clinical practice.

Chronic viral hepatitis: the histology report

In chronic viral hepatitis, the role of liver biopsy as a diagnostic test has seen a decline, paralleled by its increasing importance for prognostic purposes. Nowadays, the main indication for liver biopsy in chronic viral hepatitis is to assess the severity of the disease, in terms of both necro-inflammation (grade) and fibrosis (stage), which is important for prognosis and therapeutic management. Several scoring systems have been proposed for grading and staging chronic viral hepatitis and there is no a general consensus on the best system to be used in the daily practice. All scoring systems have their drawbacks and all may be affected by sampling and observer variability. Whatever the system used, a histological score is a reductive approach since damage in chronic viral hepatitis is a complex biological process. Thus, scoring systems are not intended to replace the detailed, descriptive, pathology report. In fact, lesions other than those scored for grading and staging may have clinical relevance and should be assessed and reported. This paper aims to provide a systematic approach to the interpretation of liver biopsies obtained in cases of chronic viral hepatitis, with the hope of helping general pathologists in their diagnostic practice.

Impact of obesity, steatosis and insulin resistance on progression and response to therapy of hepatitis C

Clinical progression of chronic hepatitis C depends on several cofactors, which also have a negative affect on the rate of response to interferon-alpha-based therapy. Given the current worldwide prevalence of the metabolic syndrome, the impact of obesity and insulin resistance, and of their histopathological correlate, hepatic steatosis, on the natural history and management of chronic hepatitis C is undoubtedly very important. We will review some of the current knowledge on the clinical consequences of overweight/obesity, steatosis and insulin resistance on chronic hepatitis C, and discuss how this issue may be dealt with in clinical practice.

Low-density lipoprotein receptor variants are associated with spontaneous and treatment-induced recovery from hepatitis C virus infection

Low-density lipoprotein receptor (LDLR) is involved in the entry of hepatitis C virus (HCV) in host cells. We investigated whether three single-nucleotide alterations within LDLR might be associated with the course of hepatitis C infection and response to antiviral therapy. We enrolled 651 individuals with chronic HCV infection who had received interferon-based combination therapy, 174 individuals with self-limited HCV infection, and 516 healthy controls. LDLR c.1171G>A, c.1413G>A, and c.*52G>A genotyping was performed by real-time PCR-based assays. HCV genotype 1-infected individuals who were homozygous for 3'UTR c.*52G were at increased risk for virologic non-response to antiviral therapy compared to virologic responders (66.3% vs. 51.0%, p=0.001). Furthermore, compared to healthy controls, self-limited HCV genotype 1 infection was significantly associated with c.1171A (15.1% vs. 6.6%, p=0.006) and negatively associated with c.1413G>A heterozygosity (33.0% vs. 46.1%, p=0.023). The data indicate that LDLR alterations are correlated with response to interferon-based combination therapy and with self-limitation of HCV 1 infection.

The pattern of pegylated interferon-α2b and ribavirin treatment failure in cirrhotic patients depends on hepatitis C virus genotype

Background

Failure of anti-hepatitis C therapy encompasses both primary non-response and post-treatment relapse. Treatment failure to pegylated interferon (PEG-IFN)-α2b and ribavirin (RBV) largely depends upon virus genotype, but the interaction between genotype, cirrhosis and pattern of treatment failure is unclear. We aimed to assess whether cirrhosis modifies the pattern of PEG-IFN-α2b and RBV treatment failure.

Methods

A total of 471 treatment-naive patients with histologically proven chronic hepatitis C virus (HCV) infection (106 with cirrhosis; 185 with HCV genotype 1 [HCV-1], 157 with HCV genotype 2 [HCV-2], 92 with HCV genotype 3 [HCV-3] and 37 with HCV genotype 4 [HCV-4]) were consecutively treated with PEG-IFN-α2b 1.5 μg weekly and weight-based RBV.

Results

The sustained virological response (SVR) rates were 31% in HCV-1 and HCV-4, 80% in HCV-2 and 72% in HCV-3, and were lower in cirrhotic than in non-cirrhotic HCV-1 and HCV-4 (17% versus 36%; P=0.01), and HCV-3 (33% versus 79%; P=0.001), but not HCV-2 (69% versus 83%; P=0.1) patients. Treatment failure was the consequence of lower end-of-treatment response rates (37% versus 53%; P=0.06) plus higher post-treatment relapse rates (55% versus 31%; P=0.07) in cirrhotic HCV-1 and HCV-4 patients and higher rates of post-treatment relapse in HCV-2 (29% versus 10%; P=0.01) and HCV-3 cirrhotic patients (61% versus 12%; P<0.001). By multi-variate analysis, HCV-1 and HCV-4 (odds ratio [OR] 7.44, 95% confidence interval [CI] 4.87–11.36), and cirrhosis (OR 3.00, 95% CI 1.80–5.00) were independent predictors of treatment failure.

Conclusions

Cirrhosis is an important moderator of SVR, accounting for different patterns of treatment failure in patients infected with different genotypes.

Host genetics, steatosis and insulin resistance among African Americans and Caucasian Americans with hepatitis C virus genotype-1 infection

Hepatic steatosis is the accumulation of fat in liver cells. Insulin resistance (IR) occurs when normal amounts of insulin do not stimulate insulin activity in cells. Both conditions have been described in hepatitis C virus (HCV) infection and are thought to be biologically related. This study examined the association of genetic variants with steatosis and IR among 167 African Americans and 184 Caucasian Americans with HCV genotype-1. Steatosis was defined as at least 5% of fat in cells on liver biopsy. IR was quantified as a score greater than 2 from the Homeostasis Model Assessment, version 2.2 (HOMA2-IR). Associations were investigated by estimating odds ratios separately by race. Statistically significant associations (p < 0.05) were observed for variants in interleukin-10 (IL10), leptin receptor (LEPR), interleukin-6 (IL6) and transforming growth factor beta-1 (TGF-beta1) for both outcomes. Some significant interactions were observed between IL10,LEPR and TGF-beta1 polymorphisms and HOMA2-IR scores when examining steatosis. The interaction of HOMA2-IR and IL10 was consistent in both races whereas for LEPR and TGF-beta1 the interactions were statistically significant in only one of the racial groups.These results could imply that some IL10,LEPR and TGF-beta1 polymorphisms may modify an association between steatosis and IR.

A mathematical model of hepatitis C virus dynamics in patients with high baseline viral loads or advanced liver disease

BACKGROUND & AIMS

Patients with baseline hepatitis C virus-RNA levels (bHCV-RNA)>6 log IU/mL or cirrhosis have a reduced probability of a sustained-virologic response (SVR). We examined the relation between bHCV-RNA, cirrhosis, and SVR with a mathematical model that includes the critical-drug efficacy (epsilonc; the efficacy required for a drug to clear HCV), the infection-rate constant (beta), and the percentage of HCV-infected hepatocytes (pi).

METHODS

The relation between baseline factors and SVR was evaluated in 1000 in silico HCV-infected patients, generated by random assignment of realistic host and viral kinetic parameters. Model predictions were compared with clinical data from 170 noncirrhotic and 75 cirrhotic patients.

RESULTS

The ranges chosen for beta and the viral production rate (p) resulted in bHCV-RNA levels that were in agreement with the distribution observed in US patients. With these beta and p values, higher bHCV-RNA levels led to higher epsilonc, resulting in lower SVR rates. However, higher beta values resulted in lower bHCV-RNA levels but higher pi and (epsilonc), predicting lower rates of SVR. Cirrhotic patients had lower bHCV-RNA levels than noncirrhotic patients (P=.013), and more had bHCV-RNA levels<6 log IU/mL (P<.001). Even cirrhotic patients with lower bHCV-RNA levels had lower SVR rates. An increase in beta could explain the results observed in cirrhotic patients.

CONCLUSIONS

Our model predicts that higher bHCV-RNA levels lead to higher epsilonc, reducing the chance of achieving SVR; cirrhotic patients have lower SVR rates because of large pi values, caused by increased rates of hepatocyte infection.

Metabolic syndrome, non-alcoholic fatty liver disease and hepatitis C virus: impact on disease progression and treatment response

Non-alcoholic fatty liver disease (NAFLD), a spectrum of liver disease ranging from simple steatosis to non-alcoholic steatohepatitis, is increasingly recognized as the hepatic manifestation of metabolic syndrome and is an important cause of liver-related morbidity and mortality. It is among the most common forms of liver disease. NAFLD reflects abnormal partitioning of fat, such that fat deposition is increased in the liver, and provides a link between NAFLD and the metabolic syndrome, a constellation of metabolic disorders that can also be associated with visceral fat or central adiposity. Together, the features of the metabolic syndrome presage overt diabetes and increase cardiovascular risk. Hepatitis C virus (HCV) appears to exacerbate the metabolic syndrome by eliciting increased insulin resistance (IR) and promoting truncal obesity. Moreover, the concomitant presence of HCV and NAFLD is associated with an increased likelihood of diabetes, hypertension and/or hypertriglyceridaemia. Metabolic abnormalities have been shown to influence response to treatment such that the presence of IR or obesity reduces the likelihood of a sustained virological response (SVR); conversely, SVR has been demonstrated to ameliorate IR and improve beta-cell function. Clinically, these data suggest that attention must be paid not only to optimizing antiviral response but also to screening for and treatment of the various components of the metabolic syndrome.

Hepatitis C Viral Kinetics in Special Populations

Mathematical models of hepatitis C viral (HCV) kinetics provide a means of estimating the antiviral effectiveness of therapy, the rate of virion clearance and the rate of loss of HCV-infected cells. They have also proved useful in evaluating the extrahepatic contribution to HCV plasma viremia and they have suggested mechanisms of action for both interferon-α and ribavirin. Viral kinetic models can explain the observed HCV RNA profiles under treatment, e.g., flat partial response, biphasic and triphasic viral decay and viral rebound. Current therapy with (pegylated) interferon-α and ribavirin has a poorer success in patients having insulin resistance, hepatic fibrosis, African American ethnicity, HCV/HIV-coinfection, HCV genotype-1 and high baseline viral load. The use of mathematical modeling and statistical analysis of experimental data have been useful in understanding some of these treatment obstacles.

Influence of metabolic syndrome on the response of chronic hepatitis C to anti-viral therapy and its possible mechanism

Genotype and viral load have been found as the most important viral factors influencing antiviral response. Host factors include metabolic syndrome such as diabetes type 2, hepatocyte steatosis, and insulin resistance. Diabetes type 2 decreases the sustained response to interferon α, and hepatocyte steatosis impairs the sustained response rate in patients with HCV genotype 1, but not in genotype 3. Insulin resistance emerges as the most important host factors in the prediction of response in chronic hepatitis C patients with interferon plus ribavirin. Most studies showed that insulin resistance may induce interferon resistance by blocking intracellular signal pathway of interferon.

The accuracy of sonography in predicting steatosis and fibrosis in chronic hepatitis C

The accuracy and clinical significance of sonography (US) in demonstrating fatty liver and hepatic fibrosis in chronic hepatitis C (CHC) are rarely reported. US had sensitivity 71.1%, specificity 72.9%, 58.7% positive predictive value (PPV), and 82.3% negative predictive value (NPV) in demonstrating histological steatosis > or =5%. US had sensitivity 85.7%, specificity 60.4%, 13% PPV, and 98.4% NPV in demonstrating histological steatosis > or =30% with clinical significance in predicting prognosis and therapeutic response in CHC. Subjects with fatty liver on US had a greater prevalence of body mass index (BMI) > or =25 kg/m2, inflammation-necrosis grade >2, and total bilirubin <1.2 mg/dl in multivariate analyses. US had sensitivity 27.4%, specificity 62.5%, 71.9% PPV, and 19.7% NPV in demonstrating histological fibrosis of stage II or above, and sensitivity 13.6%, specificity 66.3%, 9.4% PPV, and 75.0% NPV in demonstrating fibrosis of stage III or above. There was no correlation between fibrotic sonographic patterns and histological stage of fibrosis (r = -0.167, P = 0.083). Besides hepatic steatosis, clinicians should be alert to the possibility of advanced necrosis-inflammation grade in interpreting a report of bright liver on gray-scale US. Gray-scale US cannot replace liver biopsy as the optimal diagnostic procedure for the prediction of hepatic steatosis and fibrosis prior to initiating therapy for CHC.