Insulin resistance predicts sustained virological response to treatment of chronic hepatitis C independently of the IL28b rs12979860 polymorphism

Genetic polymorphisms of melatonin receptors 1A and 1B may result in disordered lipid metabolism in obese patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a condition in which a woman's levels of the sex hormones (estrogen and progesterone) are out of balance, leading to the growth of ovarian cysts. PCOS can affect the menstrual cycle, fertility, cardiac function and even appearance of women. Therefore, we aimed to explore the genetic polymorphism of the melatonin receptors 1A and 1B in obese patients with PCOS to identify a new theoretical basis for its treatment. Patients presenting with PCOS (n=359) were enrolled and classified into an obese OB-PCOS group [body mass index (BMI) of PCOS patients ≥25 kg/m²] or a nonobese NOB-PCOS group, and 215 oviduct infertile patients who experienced normal ovulation were used as the control group. All baseline characteristics, endocrine hormone levels, lipid and glucose metabolism, and insulin indices were measured. The genotypes of rs2119882 within the MTNR1A gene and of rs10830963 within the MTNR1B gene were determined by PCR-RFLP; the genotype frequency and the difference in the distribution of allele frequency were compared. For rs2119882, C allele carriers who were not diagnosed with PCOS had an increased risk of developing PCOS, and C allele carriers with PCOS had an increased risk of developing OB-PCOS. For rs10830963, G allele carriers who were not diagnosed with PCOS had an increased risk of developing PCOS. The TT genotype in rs2119882 and the CC genotype in rs10830963 were protective factors for OB-PCOS, and increased levels of LH, testosterone, and estradiol and abnormal menstruation were key risk factors for PCOS. Furthermore, the TT genotype at the rs2119882 site was the key protective factor for OB-PCOS patients. Our study found that MTNR1A rs2119882 and MTNR1B rs10830963 could increase the risk for PCOS and cause glycolipid metabolism disorder in PCOS patients.

High prevalence of insulin resistance among Brazilian chronic hepatitis C patients

OBJECTIVE

This study aims to estimate the prevalence of insulin resistance (IR) among chronic hepatitis C (CHC) patients and their related laboratory and demographic data.

SUBJECTS AND METHODS

In this study, non-diabetic CHC patients referred to Viral Hepatitis Ambulatories from Rio de Janeiro (Brazil) donated blood samples. Insulin was measured using a chemiluminescence immunoassay. IR was determined by HOMA-IR, where HOMA-IR > 2 was defined as IR.

RESULTS

A total of 214 CHC patients were recruited (123 females aged 53.6 years ± 10.9 years). IR was present in 133 patients (62.1%) and was associated in bivariate analysis to higher mean values of age (p = 0.040), triglycerides (p = 0.032), glucose (p = 0.000), insulin (p = 0.000), waist circumference (p = 0.001), and body mass index (p = 0.007); however, none of these variables were significant in the multivariate analysis.

CONCLUSIONS

The high prevalence of IR was observed among CHC patients, and there was no difference in clinical or laboratory parameters when both groups were compared in the multivariate analysis. This high IR prevalence could lead to a high risk for development of cardiovascular disease and metabolic disorders.

Diabetes mellitus, insulin resistance and hepatitis C virus infection: A contemporary review

AIM

To summarise the literature data on hepatitis C virus (HCV)-infected patients concerning the prevalence of glucose abnormalities and associated risk.

METHODS

We conducted a PubMed search and selected all studies found with the key words "HCV" or "hepatitis C virus" and "diabetes" or "insulin resistance". We included only comparative studies written in English or in French, published from January 2000 to April 2015. We collected the literature data on HCV-infected patients concerning the prevalence of glucose abnormalities [diabetes mellitus (DM) and insulin resistance (IR)] and associated risk [i.e., severe liver fibrosis, response to antivirals, and the occurrence of hepatocellular carcinoma (HCC)].

RESULTS

HCV infection is significantly associated with DM/IR compared with healthy volunteers and patients with hepatitis B virus infection. Glucose abnormalities were associated with advanced liver fibrosis, lack of sustained virologic response to interferon alfa-based treatment and with a higher risk of HCC development. As new antiviral therapies may offer a cure for HCV infection, such data should be taken into account, from a therapeutic and preventive point of view, for liver and non-liver consequences of HCV disease. The efficacy of antidiabetic treatment in improving the response to antiviral treatment and in decreasing the risk of HCC has been reported by some studies but not by others. Thus, the effects of glucose abnormalities correction in reducing liver events need further studies.

CONCLUSION

Glucose abnormalities are strongly associated with HCV infection and show a negative impact on the main liver related outcomes.

Evidence of bottleneck effect on hepatitis C virus transmission between a couple under interferon based therapy

Issues on the correlation of viral genetic diversity and treatment response to the hepatitis C infection remain uncertain. The bottleneck effect dictates the characteristics of the viral population that will establish the infection in a new host and is related to how the immune system and treatment will be effective against the virus. Here we evaluated the phylogenetic characteristics of quasispecies population and the treatment response pattern of a HCV infected couple. We also analyzed whether the viral population of these patients indicated that they were exposed to the same source for primer infection. This study included two patients (P10 and P11) HCV genotype 1b infected. The couple presented horizontal transmission. Viral RNA was isolated from serum samples collected before, during and after treatment, at specific time points. The HCV NS5A gene sequence was amplified, cloned and sequenced. Genetic and evolutionary analyses were performed to compare the quasispecies population of these two patients and local control patients. Genetic distance and diversity were calculated. Phylogenetic analyses were performed by using maximum likelihood and Bayesian methodologies. The analysis of the baseline samples showed that the genetic distance of the viral populations of patients P10 and P11 was significantly lower than when these patients and the control group based on sequences from local patients were analyzed, supporting the horizontal transmission hypothesis. Phylogenetic analysis with sequences from all the time point samples also demonstrated two patterns of evolution depending on the treatment response. The Bayesian analysis showed that one isolate corresponding to the baseline sample of P10 was grouped into the P11 clade, suggesting a way of infection and a bottleneck effect. Our data suggests that the patient P11 viral population may be originated from variants from P10 patient and consequently showing that clinical differences between treatment responses can emerge from the bottleneck effect on viral populations.

Interleukin 28B polymorphisms as predictors of sustained virological response in chronic hepatitis C: systematic review and meta-analysis

Polymorphism of interleukin 28B gene represents a powerful outcome predictor for interferon-based regimens in hepatitis C virus infection. However, some studies report conflicting results. The predictive value of interleukin 28B genotype over the outcome interferon-α/ribavirin treatment was thoroughly evaluated and compared with virological predictors of response. Literature revision was performed on PubMed. Pooled odds ratios (ORs) were calculated by fixed- or random-effects models. Heterogeneity and publication bias were also assessed. Sixty-two eligible papers including 20 290 patients were retrieved. Both polymorphisms (rs12979860 and rs8099917) were strongly associated with response (OR=4.09 and 4.00, respectively), however, the association was weaker for subjects infected with viral genotypes 2 and 3 (OR=1.52 and 1.49, respectively). Compared with interleukin 28B genotype, the association with response was lower for baseline viremia (OR=2.15) and higher for rapid virological response (OR=13.86). These results provide a critical evaluation of interleukin 28B genotype as a pharmacogenetic predictor in hepatitis C patients.

Metabolic alterations and hepatitis C: From bench to bedside

In addition to causing cirrhosis and hepatocellular carcinoma, hepatitis C virus (HCV) is thought to cause hypolipidemia, hepatic steatosis, insulin resistance, metabolic syndrome, and diabetes. The viral life cycle of HCV depends on cholesterol metabolism in host cells. HCV core protein and nonstructural protein 5A perturb crucial lipid and glucose pathways, such as the sterol regulatory element-binding protein pathway and the protein kinase B/mammalian target of rapamycin/S6 kinase 1 pathway. Although several lines of transgenic mice expressing core or full HCV proteins exhibit hepatic steatosis and/or dyslipidemia, whether they completely reflect the metabolic alterations in humans with HCV infection remains unknown. Many cross-sectional studies have demonstrated increased prevalences of metabolic alterations and cardiovascular events in patients with chronic hepatitis C (CHC); however, conflicting results exist, primarily due to unavoidable individual variations. Utilizing anti-HCV therapy, most longitudinal cohort studies of CHC patients have demonstrated the favorable effects of viral clearance in attenuating metabolic alterations and cardiovascular risks. To determine the risks of HCV-associated metabolic alterations and associated complications in patients with CHC, it is necessary to adjust for crucial confounders, such as HCV genotype and host baseline glucose metabolism, for a long follow-up period after anti-HCV treatment. Adipose tissue is an important endocrine organ due to its release of adipocytokines, which regulate lipid and glucose metabolism. However, most data on HCV infection and adipocytokine alteration are inconclusive. A comprehensive overview of HCV-associated metabolic and adipocytokine alterations, from bench to bedside, is presented in this topic highlight.

Effect of aging, glucose level, and HIV viral load on response to treatment with pegylated interferon plus ribavirin in HIV/HCV co-infected women

BACKGROUND

This was a post-hoc analysis of the Optimized Pegylated interferons Efficacy and anti-Retroviral Approach (OPERA) study, originally designed to document routine clinical and treatment data in HIV/HCV coinfected patients treated with pegylated interferon/ribavirin (PEG-IFN/RBV). The aim of this study was to define the impact of several variables, such as age, glucose metabolism, and HIV viral load, on PEG-IFN/RBV treatment outcomes, in HIV/HCV coinfected women.

METHODS

Female subjects from the OPERA database were retrospectively evaluated and factors associated with sustained virological response (SVR) were assessed and compared to the male population by logistic regression analysis. At baseline, clinical and demographic data were collected. Patients were then administered with PEG-IFN/RBV therapy for 48 weeks. After a 24-week follow-up period, SVR was evaluated.

RESULTS

A total of 1523 patients were enrolled in 98 centers across Italy, 1284 of whom were IFN therapy naïve and were included in the post-hoc analysis. In the female group, factors associated with SVR were the presence of HCV genotype 2,3 (adjusted odds ratio [AOR]=6.87, p<0.0001), age ≤45 years (AOR=2.61, p=0.014), ≥80% exposure to PEG-IFN (AOR=3.85, p=0.019) and RBV (AOR=3.94, p=0.015) therapy. Also, increased glucose plasma level negatively correlated with SVR (AOR=0.98, p=0.066). In the male population, undetectable HIV-RNA (AOR=1.47, p=0.033) but not glucose level (AOR=1.0, p=0.95) predicted SVR.

CONCLUSIONS

Findings from the present study demonstrate that several factors may be predictive of SVR when pegylated interferon plus ribavirin is used (i.e., age, gender, HIV viral load and HCV genotype) that need to be carefully considered prior to therapeutic intervention, since they may hinder successful therapy. Use of PEG-IFN/RBV with novel direct antiviral agents will likely be still maintained until less expensive and effective interferon-free strategies become available.

Characterisation of the cytokine milieu associated with the up-regulation of IL-6 and suppressor of cytokine 3 in chronic hepatitis C treatment non-responders

BACKGROUND & AIMS

In chronic hepatitis C virus infection (CHC), expression of suppressor of cytokine signalling-3 (SOCS3) has been shown to be associated with obesity and non-response to antiviral therapy. In this study, we aimed to determine the effect of SOCS3 induction on the cytokine response in patients receiving Pegylated interferon (PegIFN) and ribavirin (RBV) therapy.

METHODS

Peripheral blood mononuclear cells (PBMC) collected at baseline and at 12 weeks from CHC patients receiving PegIFN/RBV therapy were examined for mRNA and protein SOCS3 expression. Immunological assays were employed to examine cytokine production.

RESULTS

There was increased expression of SOCS3 in PBMC of non-responders at week 12 of therapy, when compared to treatment responders (P = 0.0001). The expression of SOCS3 correlated with body mass index (BMI) (r = 0.54; P = 0.01). Patients with low SOCS3 expression at week 12 of therapy had lower HCV-specific IFN-γ production in enzyme-linked immunosorbent spot (ELISpot) assays (P = 0.01), and reduced ex-vivo production of the anti-HCV effector cytokines interleukin (IL)-2 and tumour necrosis factor (TNF)-α(P = 0.01 and P = 0.04 respectively). Analysis of serum cytokine levels revealed higher levels of IL-6 at week 12 in the high SOCS3 expression group (P = 0.02) while IL-6 levels correlated with SOCS3 expression in the entire cohort (P = 0.04). Ex-vivo studies confirmed that IL-6 induced SOCS3, and neutralisation of IL-6 reduced levels of SOCS3.

CONCLUSION

In subjects with increased BMI and non-response to antiviral therapy, the IL-6/SOCS3 axis appears to play a crucial role in altering the anti-HCV-cytokine response associated with antiviral therapy.

Validation of TaqMan® SNP genotyping specificity for rs12979860 of IL-28B: modeling primer specificity in vitro

Members of the type III interferon gene family arose by gene duplication events and have retained a high percent identity both in their coding and non-coding regions. In this study, the specificity of a widely used TaqMan(®) SNP genotyping assay for rs12979860 is validated. The 66 bp template for SNP genotyping has only 3 bp at one 5' end that vary between IL-28B and IL-28A; excluding the rs12979860 SNP itself. Conflicting annealing temperatures were found for the mismatched 19 bp primer to IL-28B and IL-28A with in silico melting temperature algorithms, or with in vitro dissociation curves. In order to prove specificity for IL-28B, an in vitro competition assay was setup with genomic DNA and synthetic oligonucleotides. When genomic DNA, containing equimolar concentrations of rs12979860 and the homologous region of IL-28A are present, no off-target amplification was observed. This SNP genotyping assay is therefore specific for rs12979860 and all previously reported results are valid. Finally, using a completely synthetic in vitro competition assay it was possible to calculate the amount of off-target template that will produce 1/2 the maximum on-target (VIC) fluorescent signal, a value that is between a C/C genotype and a T/T genotype. This value is defined in the manuscript as the half maximum positive value, KHPV, and in the present assay KHPV is 15.75±0.0721, represented as the relative fold increase in the amount of IL-28A over rs12979860. This method will be of interest to those performing genotyping on highly conserved gene families.

Review article: HCV genotype 3 – the new treatment challenge

BACKGROUND

Over the past several years, hepatitis C therapy has been pegylated interferon and ribavirin based. Although protease inhibitor-based therapy has enhanced response rates in genotype 1, the recent advances in therapy have demonstrated a challenge in genotype 3, a highly prevalent infection globally.

AIM

To provide a comprehensive summary of the literature evaluating the unique characteristics and evolving therapies in genotype 3.

METHODS

A structured search in PubMed, the Cochrane Library and EMBASE was performed using defined key words, including only full text papers and abstracts in English.

RESULTS

HCV genotype 3 is more prevalent in Asia and among intra-venous drug users. Furthermore, it interferes with lipid and glucose metabolism, and the natural history involves a more rapid progression of liver disease and a higher incidence of hepatocellular carcinoma (HCC). New therapies with protease inhibitors have focused on genotype 1 largely and have demonstrated enhanced responses, but have limited activity against genotype 3. Thus far, in clinical trials, NS5B and NS5A inhibitors have performed more poorly in genotype 3, while a cyclophilin inhibitor, alisporivir, has shown promise.

CONCLUSIONS

As treatments for HCV have evolved, genotype 3 has become the most difficult to treat. Furthermore, genotype 3 has special characteristics, such as insulin resistance and alterations in lipid metabolism, which may partly explain the lower treatment responses. A great deal of emphasis on advancing therapy is needed in this population that appears to have a more rapid progression of liver disease and a higher incidence of HCC.

Individualization of chronic hepatitis C treatment according to the host characteristics

Hepatitis C virus (HCV) infection is a global health problem that affects more than 170 million people worldwide. It is a major cause of cirrhosis and hepatocellular carcinoma, making the virus the most common cause of liver failure and transplantation. The standard-of-care treatment for chronic hepatitis C (CHC) has been changed during the last decade and direct acting antiviral drugs have already been used. Besides, understanding of the pathogenesis of CHC has evolved rapidly during the last years and now several host factors are known to affect the natural history and response to treatment. Recent genome-wide association studies have shown the important role of interleukin-28B and inosine triphosphatase in HCV infection. The present review article attempts to summarize the current knowledge on the role of host factors towards individualization of HCV treatment.

IL28RA polymorphism (rs10903035) is associated with insulin resistance in HIV/HCV-coinfected patients

Hepatitis C virus (HCV) infection is associated with insulin resistance (IR), although mechanisms leading to IR in these patients are not completely understood. The aim of this study was to evaluate the association of interleukin 28B (IL28B) and interleukin 28 receptor alpha (IL28RA) polymorphisms with IR among human immunodeficiency virus (HIV)/HCV-coinfected patients. We carried out a cross-sectional study on 203 patients. IL28B (rs8099917) and IL28RA (rs10903035) polymorphisms were genotyped by GoldenGate(®) assay. IR was defined as homeostatic model assessment (HOMA) values ≥3.00. Univariate and multivariate generalized linear models (GLM) were used to compare HOMA values and the percentage of patients with IR according to IL28B and IL28RA genotypes. In total, 32% (n = 65/203) of the patients had IR. IL28B rs8099917 TT was not significantly associated with HOMA values and IR. In contrast, rs10903035 AA was significantly associated with high HOMA values taking into account all patients (P = 0.024), as well as the subgroups of patients with significant fibrosis (P = 0.047) and infected with HCV genotype 3 (P = 0.024). Additionally, rs10903035 AA was significantly associated with IR (HOMA ≥3.00) in all patients (adjusted odds ratio (aOR) = 2.02; P = 0.034), in patients with significant fibrosis (aOR = 2.86; P = 0.039) and HCV genotype 3 patients (aOR = 4.89; P = 0.031). In conclusions, IL28RA polymorphism (rs10903035) seems to be implicated in the glucose homeostasis because AA genotype increases the likelihood of IR, but this association was different depending on hepatic fibrosis and HCV genotype.

Interleukin 28B genotype and insulin resistance in chronic hepatitis C patients

BACKGROUND

In patients with chronic HCV infection, an association between IL28B genotype and insulin-resistance (IR), known predictors of sustained virological response (SVR) to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy, has been reported. The aim of this study was to investigate the association of IR and IL28B genotype in two cohorts of well-characterized HCV patients.

METHODS

A total of 480 non-diabetic HCV patients were analysed: 391 patients who received PEG-IFN/RBV in the MIST study and 89 previously reported patients followed at a metabolic liver diseases centre (Division of Internal Medicine, Fondazione IRCCS Ospedale Maggiore Policlinico, Milan, Italy). All were tested for IL28B rs12979860 single nucleotide polymorphism by real-time PCR and had IR measured by HOMA-IR. Staging of liver disease through liver biopsy was available for all patients.

RESULTS

Overall, 164 patients (34%) were IL28B CC. Mean HOMA-IR values (±sd) did not differ according to IL28B genotype, being respectively 1.14 ±0.79 in CC versus 1.14 ±0.78 in CT/TT (P=1.0) in the first, and 2.4 ±1.0 versus 2.5 ±1.0 (P=0.7) in the second cohort. HOMA-IR>2 was not associated with IL28B genotype: 16/132 (12%) CC versus 31/259 (12%) CT/TT (P=1.0) in the first cohort and 16/32 (50%) versus 37/57 (65%; P=0.18) in the second. This held true also when using different HOMA cutoffs (>2.5, >3.0, >3.5 and >4.0). In the MIST cohort, HOMA-IR>2 did not influence treatment outcome, SVR rates being 28/47 (60%) in HOMA-IR>2 versus 214/344 (62%) in HOMA-IR≤2 (P=0.8). IL28B genotype was a strong predictor of SVR: 84% (111/132) in CC versus 51% (131/259) in CT/TT patients (P<0.0001).

CONCLUSIONS

In two cohorts of non-diabetic HCV patients where IL28B genotype predicted treatment outcome, we found no association between IL28B genotype and HOMA-IR.

Hepatitis C virus infection alters lipid metabolism depending on IL28B polymorphism and viral genotype and modulates gene expression in vivo and in vitro

Hepatitis C virus (HCV) interacts with lipid receptors to enter the cell, circulates as lipoviroparticle and is secreted as VLDL. We aimed to investigate the role of the rs12979860 polymorphism in the IL28B gene in 143 with chronic hepatitis C genotype 1, 144 infected with genotype 3, 90 genotype 4 and 413 noninfected individuals on lipid profile and to test the impact of HCV infection in an in vitro model on VLDL biosynthesis-related gene expression rs12979860 polymorphism was analysed using real-time PCR coupled to Fluorescence Resonance Energy Transfer (FRET). Huh7.5 (rs12979860 CT) and Huh7 (genotype CC) cells were infected with JFH-1 particles and serum from patients infected with genotypes 1 and 3. Gene expression of apolipoprotein B (apoB), microsomal triglyceride transfer protein (MTP), acetyl CoA carboxylase (ACC), diacylglycerol acyltransferase 2 (DGAT2), diacylglycerol acyltransferase 1 (DGAT1) and low-density lipoprotein receptor (LDLr) genes were determined by semiquantitative RT-PCR in vivo and in vitro. Genotype CC rs12979860 polymorphism was associated with significantly higher serum LDL and total cholesterol levels in patients with hepatitis C genotype 1 but not in patients with hepatitis C genotype 3, genotype 4 and control (noninfected) population. Genotype CC was more often seen in genotype 3 and healthy people in comparison with genotype 1; P = 0.001. In vitro results showed that HCV infection promotes lipid metabolism gene expression induction depending on viral genotype, but to a lesser extent in cells with CT genotype. These results demonstrate that IL28B genotype influences lipid metabolism in patients with hepatitis C but not in noninfected and it seems to be viral genotype-mediated. HCV infection modifies lipid-related genes expression (DGAT1 and DGAT2) in cultured cells based on viral genotype and IL28 polymorphism.

Are metabolic factors still important in the era of direct antiviral agents in patients with chronic hepatitis C?

The high rate of sustained viral response (SVR) to boceprevir or telaprevir-based triple therapy in hepatitis C (HCV)-related, non-cirrhotic naïve patients or relapsers to previous antiviral treatment leads clinicians to believe that the impact of metabolic host factors on SVR is minimal when triple therapy is used, unlike what is observed with the peginterferon and ribavirin schedules. This concept is strongly expressed by some opinion leaders on the basis of the data derived from sub-analyses of registrative trials as well as from a post-hoc analysis of the phase II C208 clinical trial. The perception of unrestrainable therapeutic success with the use of newer, more powerful antivirals is now reinforced by the brilliant results obtained with sofosbuvir, an HCV NS5B polymerase inhibitor, as well as by the data from the phase II and III studies on the various combinations of second-generation NS3/4A inhibitors and NS5A and/or NS5B inhibitors. However, a great deal of concern has emerged from the real world scenario in which patients are often older and have more comorbidities than patients in the “world of trials”. Furthermore, many of them have advanced fibrosis and previous failure with peginterferon and ribavirin treatment. Some data from the recent literature suggest that the host metabolic factors may play a minor but non-negligible role in these difficult-to-treat patients, an issue that will hopefully be investigated in further studies. This editorial aims to provide a detailed analysis of the role that host metabolic factors played in the past and what role they may play in the era of direct antiviral agents.

Interaction of IFNL3 with insulin resistance, steatosis and lipid metabolism in chronic hepatitis C virus infection

Metabolic changes are inextricably linked to chronic hepatitis C (CHC). Recently polymorphisms in the IFNL3 (IL28B) region have been shown to be strongly associated with spontaneous and treatment induced recovery from hepatitis C virus (HCV) infection. Further, circumstantial evidence suggests a link between IFNL3 single nucleotide polymorphisms and lipid metabolism, steatosis and insulin resistance in CHC. The emerging picture suggests that the responder genotypes of IFNL3 polymorphisms are associated with a higher serum lipid profile, and less frequent steatosis and insulin resistance. This review analyzes the current data regarding this interaction and its meaning for HCV pathogenesis and disease progression.