IL28B alleles associated with poor hepatitis C virus (HCV) clearance protect against inflammation and fibrosis in patients infected with non-1 HCV genotypes

Polymorphism Near the Interleukin-28B Gene and Anti-Hepatitis C Viral Response

In a recent genome-wide association study, single nucleotide polymorphisms (SNPs) located near the interleukin-28B gene (IL28B), which encodes type III interferon (IFN) λ3, were shown to be strongly associated with a viral response to pegylated IFNα (PEG-IFNα) and ribavirin (RBV) combination therapy and spontaneous viral clearance in patients chronically and acutely infected with hepatitis C virus (HCV), respectively. The global distribution of allele frequencies shows a remarkable pattern, in which a favorable allele is nearly fixed in East Asia, has an intermediate frequency in Europe, and is least frequent in Africa. Although the underlying mechanisms responsible for viral responses associated with IL28B SNPs have not been completely elucidated, IFN-stimulated gene expression in patients with unfavorable IL28B genotypes tends to be high at baseline and is insufficiently induced by exogenous IFN administration, resulting in poor treatment outcomes. Clinically, triple therapy with PEG-IFNα/RBV together with direct-acting antiviral agents (DAAs) is currently used to treat chronic hepatitis C as a first-line therapy. Although the predictive power of IL28B status may be attenuated, the IL28B genotype will remain relevant to the outcomes of DAA therapy when used in combination with PEG-IFNα as a backbone. Even with the introduction of IFN-free therapies with a new class of highly effective DAAs, IL28B SNPs are still useful predictors of treatment outcomes and can be used to individualize treatment strategies to maximize cost-effectiveness and identify patients at risk of being refractory to treatment. This review summarizes the current understanding of the clinical significance and role of IL28B in HCV infection and response to therapy.

Deep-sequencing analysis of the association between the quasispecies nature of the hepatitis C virus core region and disease progression

Variation of core amino acid (aa) 70 of hepatitis C virus (HCV) has been shown recently to be closely correlated with liver disease progression, suggesting that the core region might be present as a quasispecies during persistent infection and that this quasispecies nature might have an influence on the progression of disease. In our investigation, the subjects were 79 patients infected with HCV genotype 1b (25 with chronic hepatitis [CH], 29 with liver cirrhosis [LC], and 25 with hepatocellular carcinoma [HCC]). Deep sequencing of the HCV core region was carried out on their sera by using a Roche 454 GS Junior pyrosequencer. Based on a plasmid containing a cloned HCV sequence (pCV-J4L6S), the background error rate associated with pyrosequencing, including the PCR procedure, was calculated as 0.092 ± 0.005/base. Deep sequencing of the core region in the clinical samples showed a mixture of "mutant-type" Q/H and "wild-type" R at the core aa 70 position in most cases (71/79 [89.9%]), and the ratio of mutant residues to R in the mixture increased as liver disease advanced to LC and HCC. Meanwhile, phylogenetic analysis of the almost-complete core region revealed that the HCV isolates differed genetically depending on the mutation status at core aa 70. We conclude that the core aa 70 mixture ratio, determined by deep sequencing, reflected the status of liver disease, demonstrating a significant association between core aa 70 and disease progression in CH patients infected with HCV genotype 1b.

Retreatment with peg-interferon and ribavirin in patients with chronic hepatitis C virus genotype 2 or 3 infection with prior relapse

OBJECTIVES

Uncertainty remains regarding the efficacy of retreatment with current standard-of-care peg-interferon (peg-IFN) and ribavirin among patients infected with hepatitis C virus (HCV) genotypes 2 or 3 with relapse after prior therapy.

MATERIALS AND METHODS

Seventy-one patients with chronic HCV genotype 2/3 with prior relapse were enrolled in a phase III multicenter study. Patients were retreated with peg-IFNα-2a 180 μg per week and ribavirin 1000/1200 mg daily. Patients having received previous therapy for 24 weeks were retreated for 48 weeks (Group A), whereas patients having received at least 12 weeks but less than 24 weeks of treatment were allocated to either 48 (Group B) or 24 weeks (Group C) on the basis of whether they had achieved rapid virological response (RVR).

RESULTS

Sustained virological response (SVR) rates of 53%, 81% and 75% were achieved in groups A, B and C, respectively. Patients with favorable baseline characteristics, e.g., less advanced liver fibrosis, age <40 years, duration of infection <20 years, or BMI < 25 kg/m(2), tended to have more favorable outcomes. All patients achieving HCV RNA below 1000 IU/mL day 6 achieved SVR in contrast to none of the patients with detectable HCV RNA at week 12.

CONCLUSIONS

Retreatment with peg-IFN and ribavirin for 24-48 weeks entails SVR among the majority of HCV genotype 2/3 infected patients with prior relapse. However, in light of the prolonged treatment duration, moderate effect and considerable side effects, deterring therapy until new options are available may be preferential, particularly in patients previously treated for 24 weeks.

'Favourable' IL28B polymorphisms are associated with a marked increase in baseline viral load in hepatitis C virus subtype 3a infection and do not predict a sustained virological response after 24 weeks of therapy

IL28B host genetic make-up is known to play a critical role in the outcome of genotype 1 hepatitis C virus (HCV) infection in the context of both primary infection and therapy. However, the role of IL28B in subtype 3a infection remains unclear, and has not yet been assessed in the UK population where subtype 3a is dominant. In this study, we evaluated the role of the IL28B single-nucleotide polymorphism rs8099917 in 201 patients recruited from two well-defined cohorts (from Nottingham and Oxford), treated with the standard-of-care therapy of pegylated interferon and ribavirin for 24 weeks. We showed that the 'favourable' IL28B gene was associated with a rapid virological response to therapy at 4 weeks (P<0.0001), but not with a sustained virological response to therapy. The median viral load at baseline, before therapy, was markedly increased in people with the 'favourable' IL28B genotype [median viral load for the TT allele, 925,961 IU ml(-1) (range 2200-21,116,965 IU ml(-1)), and for the GT or GG allele, 260,284 IU ml(-1) (range 740-7,560,000 IU ml(-1)); P = 0.0010]. Our results suggest that the host genetic response plays an important role in early viral clearance of subtype 3a virus from the blood. However, significant reservoirs of infection must persist, as viral relapse is common, even in those with the favourable host genotype.

Differential effects of donor and recipient IL28B and DDX58 SNPs on severity of HCV after liver transplantation

BACKGROUND & AIMS

IL28B single nucleotide polymorphisms are strongly associated with spontaneous HCV clearance and treatment response in non-transplant populations. A DDX58 single nucleotide polymorphism is associated with the antiviral response of innate lymphocytes. We aimed at evaluating the associations of donor and recipient IL28B (rs12979860 and rs8099917) and DDX58 (rs10813831) genotypes with severity of HCV recurrence after liver transplantation.

METHODS

In a case-control study of 523 liver transplantation recipients with HCV, we matched severe with mild recurrent HCV based on 2-year clinical and histologic follow-up. A total of 440 liver transplantation recipients (severe, n=235; mild, n=205) with recipient DNA and 225 (severe, n=123; mild, n=102) with both recipient and donor DNA were analyzed.

RESULTS

IL28B [rs12979860, non-CC (vs. CC) and rs8099917, non-TT (vs. TT)] in the recipient-only analysis had higher risk of severe recurrent HCV [OR 1.57 and 1.58, p<0.05]. However, for the 225 with donor and recipient DNA, IL28B rs12979860 CC (vs. non-CC) and rs8099917 TT (vs. non-TT) and DDX58 rs10813831 non-GG (vs. GG) were associated with more (not less) severe recurrent HCV. The greatest risk of severe recurrent HCV was for rs12979860 CC donors in non-CC recipients (OR 7.02, p <0.001, vs. non-CC donor/recipient) and for rs8099917 TT donors in non-TT recipients (OR 5.78, p=0.001, vs. non-TT donor/recipient). These associations persisted after controlling for donor age, donor race, and donor risk index.

CONCLUSIONS

IL28B and DDX58 single nucleotide polymorphisms that are favorable when present in the non-transplant setting or in the recipient are unfavorable when present in a donor liver graft.

Effects of IL28B rs12979860 CC genotype on metabolic profile and sustained virologic response in patients with genotype 1 chronic hepatitis C

BACKGROUND & AIMS

Patients with genotype 1 chronic hepatitis C (G1 CHC) frequently develop steatosis and insulin resistance (IR), caused by metabolic and viral factors. These accelerate the progression of liver disease and reduce the response to therapy. A sustained virologic response (SVR) to therapy in patients with G1 CHC is associated strongly with polymorphisms near the interleukin-28B (IL28B) gene, but the interaction between IL28B genotype and IR, and their combined effects on SVR, have not been defined. We tested the association between the IL28B rs12979860 single-nucleotide polymorphism and metabolic features, including IR, and evaluated their effects on SVR.

METHODS

We performed genotype analysis of IL28B rs12979860 for 434 white G1 CHC patients who underwent consecutive biopsy analysis at 3 tertiary centers. Metabolic profile analyses included assessments of lipid levels and IR by the homeostasis model assessment.

RESULTS

Patients with the CC polymorphism in IL28B had higher levels of total and low-density lipoprotein cholesterol, lower levels of triglycerides, and a lower prevalence of IR and moderate-severe steatosis (P < .05) than patients without this genotype. By multiple logistic regression analysis, body mass index (odds ratio [OR], 1.223; P < .001), level of triglycerides (OR, 1.007; P = .006), the CC polymorphism in IL28B (OR, 0.378; P = .001), and levels of HCV RNA greater than 850,000 IU/mL (OR, 1.803; P = .01) were associated with IR. The CC polymorphism in IL28B (OR, 8.350; P < .001) and IR (OR, 0.432; P = .005), but not steatosis (OR, 0.582; P = 0.25), was associated with an SVR.

CONCLUSIONS

In white patients with G1 CHC, the IL28B rs12979860 CC genotype is associated with reduced IR. IL28B rs12979860 genotype and IR by the homeostasis model assessment strongly affect the outcome of antiviral therapy.

Thyroid disease in chronic hepatitis C infection treated with combination interferon-α and ribavirin: management strategies and future perspective

OBJECTIVE

Hepatitis C virus (HCV) infection is one of the major epidemics afflicting young people in both developed and developing countries. The most common endocrine disorder associated with this infection, especially in conjunction with interferon-α (IFN-α)-based therapy, is thyroid disease (TD). This review examines the development of TD before, during, and after the completion of treatment with combination IFN-α and ribavirin (RBV) for chronic HCV infection. We also summarize the current understanding of the natural history of the condition and propose management and follow-up guidelines.

METHODS

PubMed was searched up to June 30, 2011 for English-language publications that contained the search terms "hepatitis C virus," "chronic hepatitis C," "HCV," "thyroid disease," "thyroiditis," "autoimmunity," "interferon-alpha," and "ribavirin." Additional publications were identified from the reference lists of identified papers. The included studies were original research publications and included combination IFN-α and RBV use in patients that developed TD.

RESULTS

The prevalence of TD before combination IFN-α and RBV therapy ranges from 4.6 to 21.3%; during therapy, 1.1 to 21.3%; and after therapy, 6.7 to 21.3%. The most common TD is thyroiditis. Thyroid function testing (TFT) frequency and diagnostic criteria for various thyroid conditions are not standardized, and many of the existing studies are retrospective.

CONCLUSION

Patients undergoing this therapy should be assessed with a standardized protocol to appropriately detect and manage developed TD. Based on the currently available literature, we recommend that patients receiving combination interferon-α and RBV therapy undergo monthly thyrotropin (TSH) level testing.

IL28B polymorphisms are associated with severity of liver disease in human immunodeficiency virus (HIV) patients coinfected with hepatitis C virus

OBJECTIVE

To evaluate the association of IL28B polymorphisms and severity of liver disease among human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients.

METHODS

We carried out a cross-sectional study on 223 patients. Liver biopsies were evaluated according to Metavir score. IL28B polymorphisms (rs12980275, rs8099917, rs7248668, and rs11881222) were genotyped using GoldenGate(®) assay.

RESULTS

IL28B polymorphisms were in strong linkage disequilibrium, especially the couples rs12980275/rs11881222 and rs8099917/rs7248668. For all patients, the rs12980275 A allele increased the odds for significant fibrosis (F ≥ 2) odds ratio (OR) = 1.68; p = 0.018) and more rapid fibrosis progression (FPR ≥ 0.075 fibrosis units/year) (OR = 1.64; p = 0.035), and decreased the odds for liver steatosis (OR = 0.61; p = 0.046). Furthermore, the rs8099917 T allele increased the odds for F ≥ 2 (OR = 1.93; p = 0.020), FPR ≥ 0.075 (OR = 2.08; p = 0.021), and elevated ALT (≥80 IU/l) (OR = 1.78; p = 0.048). For HCV-genotype 1 patients, rs12980275 A and rs8099917 T alleles decreased the odds for liver steatosis (OR = 0.22; p < 0.001 and OR = 0.39; p = 0.048; respectively). For HCV-genotype 3 patients, the rs12980275 A allele increased the odds for F ≥ 2 ((OR = 6.30; p = 0.012), FPR ≥ 0.075 (OR = 6.40; p = 0.025), and elevated ALT (OR = 4.12; p = 0.037); and the rs8099917 T allele also increased the odds for F ≥ 2 (OR = 7.56; p = 0.027), FPR ≥ 0.075 (OR = 50.8; p = 0.012), and elevated ALT (OR = 5.39; p = 0.043). However, we did not find significant trends in patients infected with HCV-genotype 4.

CONCLUSION

The major alleles of IL28B (rs12980275 A, rs11881222 A, rs8099917 T, and rs7248668 G) are associated with increased odds of liver disease severity in HIV patients infected with HCV-genotype 3. In contrast, HCV-genotype 1 patients carrying the major alleles of IL28B polymorphisms had lower odds for liver steatosis.

Genetic variation in the interleukin-28B gene is associated with spontaneous clearance and progression of hepatitis C virus in Moroccan patients

BACKGROUND

Genetic variation in the IL28B gene has been strongly associated with treatment outcomes, spontaneous clearance and progression of the hepatitis C virus infection (HCV). The aim of the present study was to investigate the role of polymorphisms at this locus with progression and outcome of HCV infection in a Moroccan population.

METHODS

We analyzed a cohort of 438 individuals among them 232 patients with persistent HCV infection, of whom 115 patients had mild chronic hepatitis and 117 had advanced liver disease (cirrhosis and hepatocellular carcinoma), 68 individuals who had naturally cleared HCV and 138 healthy subjects. The IL28B SNPs rs12979860 and rs8099917 were genotyped using a TaqMan 5' allelic discrimination assay.

RESULTS

The protective rs12979860-C and rs8099917-T alleles were more common in subjects with spontaneous clearance (77.9% vs 55.2%; p = 0.00001 and 95.6% vs 83.2%; p = 0.0025, respectively). Individuals with clearance were 4.69 (95% CI, 1.99-11.07) times more likely to have the C/C genotype for rs12979860 polymorphism (p = 0.0017) and 3.55 (95% CI, 0.19-66.89) times more likely to have the T/T genotype at rs8099917. Patients with advanced liver disease carried the rs12979860-T/T genotype more frequently than patients with mild chronic hepatitis C (OR = 1.89; 95% CI, 0.99-3.61; p = 0.0532) and this risk was even more pronounced when we compared them with healthy controls (OR = 4.27; 95% CI, 2.08-8.76; p = 0.0005). The rs8099917-G allele was also associated with advanced liver disease (OR = 2.34; 95% CI, 1.40-3.93; p = 0.0100).

CONCLUSIONS

In the Moroccan population, polymorphisms near the IL28B gene play a role both in spontaneous clearance and progression of HCV infection.

Interleukin 28B rs12979860 (CT/TT) genotype is associated with milder hepatic damage in the natural evolution of HCV/HIV coinfection

Hepatitis C virus (HCV)/human immunodefficiency virus (HIV) coinfection is a major health problem, affecting mostly to individuals with exposure to blood products, as hemophiliacs or intravenous drug users, or those exposed to high-risk sexual practices. Genotyping of interleukin 28B (IL-28B) rs12979860 polymorphism is a useful tool for guiding therapeutic decisions in this disease. On the contrary, there is not enough information on the pathogenic role of this polymorphism in the natural history of the disease. The objective of this study is to describe the relationships between the CT/TT genotype of this polymorphism with viral loads and also with a number of biomarkers of liver function in coinfected patients naïve for treatment for HCV. Seventy-five HCV/HIV coinfected patients were retrospectively recruited in our Hospital from 2010 to 2011. Logistic regression analysis adjusting by [Age], [Sex], [HCV viral genotype], [HCV viral load], [HIV viral load], and [CD4 T cells levels] revealed the IL-28B rs12979860 (CT/TT) genotype as a protective factor against alanine aminotransferase (ALT) levels (>100 IU/L), aspartate aminotransferase (AST) levels (>75 IU/L), and AST-to-platelet ratio index (APRI) score for liver fibrosis (>1.5) [OR, (95% CI), p]: ALT [0.026 (0.001-0.576) 0.021]; AST [0.001 (0.000-0.297) 0.019]; APRI [0.031 (0.002-0.41) 0.008]. Stepwise regression analysis considering the same adjusting variables showed the same results. In consequence, the IL-28B rs12979860 (CT/TT) genotype, which is a marker of poor response to HCV treatment, could be mediating on the contrary a certain protective effect against the hepatic damage caused by this virus in patients coinfected by HIV.

Complicated relationships of amino acid substitution in hepatitis C virus core region and IL28B genotype influencing hepatocarcinogenesis

The impact of amino acid (aa) 70 substitution in the core region on hepatocarcinogenesis and survival for liver-related death in patients of hepatitis C virus (HCV) genotype 1b (HCV-1b), who had not received antiviral therapy, is unknown. The relationships among aa 70 substitution, IL28B genotype, and hepatocarcinogenesis are also not clear. A total of 1,181 consecutive HCV-infected patients, who had not received antiviral therapy, were included in a follow-up study to determine predictive factors of hepatocarcinogenesis and survival for liver-related death. The cumulative hepatocarcinogenesis rates in HCV-1b of Gln70(His70) (glutamine (histidine) at aa 70) were significantly higher than those in HCV-1b of Arg70 (arginine at aa 70) and HCV-2a/2b. The cumulative survival rates for liver-related death in HCV-1b of Gln70(His70) were significantly lower than those in HCV-1b of Arg70 and HCV-2a/2b. Multivariate analysis identified gender (male), age (≥ 60 years), albumin (<3.9 g/dL), platelet count (<15.0 × 10(4) /mm(3) ), aspartate aminotransferase (≥ 67 IU/L), and HCV subgroup (HCV-1b of Gln70(His70)) as determinants of both hepatocarcinogenesis and survival rates for liver-related death. In HCV-1b patients, the cumulative change rates from Arg70 to Gln70(His70) by direct sequencing were significantly higher than those from Gln70(His70) to Arg70. In patients of Arg70 at the initial visit, the cumulative change rates from Arg70 to Gln70(His70) in IL28B rs8099917 non-TT genotype were significantly higher than those in the TT genotype.

CONCLUSION

Substitution of aa 70 in the core region of HCV-1b is an important predictor of hepatocarcinogenesis and survival for liver-related death in HCV patients who had not received antiviral therapy. The IL28B genotype might partly affect changes over time of dominant amino acid in core aa 70 of HCV-1b.

Host genetic variants in the pathogenesis of hepatitis C

Direct-acting antiviral drugs (DAAs) are currently replacing antiviral therapy for Hepatitis C infection. Treatment related side effects are even worse and the emergence of resistant viruses must be avoided because of the direct-antiviral action. Altogether it remains a challenge to take treatment decisions in a clinical setting with cost restrictions. Genetic host factors are hereby essential to implement an individualized treatment concept. In recent years results on different genetic variants have been published with a strong association with therapy response, fibrosis and treatment-related side effects. Polymorphisms of the IL28B gene were identified as accurate predictors for therapy response and spontaneous clearance of HCV infection and are already used for diagnostic decisions. For RBV-induced side effects, such as hemolytic anemia, associations to genetic variants of inosine triphosphatase (ITPA) were described and different SLC28 transporters for RBV-uptake have been successfully analyzed. Fibrosis progression has been associated with variants of Vitamin D receptor (VDR) and ABCB11 (bile salt export pump). Cirrhotic patients especially have a high treatment risk and low therapy response, so that personalized antiviral treatment is mandatory. This review focuses on different host genetic variants in the pathogenesis of Hepatitis C at the beginning of a new area of treatment.

Genomics and HCV infection: progression of fibrosis and treatment response

HCV infection is a global health problem that affects 170 million people worldwide. The severity of the disease varies from asymptomatic chronic infection to cirrhosis and hepatocellular carcinoma (HCC). Recently, the standard of care for genotype 1 patients has greatly improved with the addition of protease inhibitors (telaprevir or boceprevir) to pegylated interferon (PegIFN) and ribavirin (RBV). The prediction of fibrosis progression and the response to antiviral treatment are two major issues in the management of patients with chronic hepatitis C. Differential expression of mRNAs was first analyzed for both progression of fibrosis and treatment response. Specific polymorphisms, associated with either fibrosis or viral response, were identified thanks to major improvements in genome scanning technologies. Since 2009, several independent genome wide association studies (GWAS) have reported an association between genetic polymorphisms within the IL-28B promoter and both natural and treatment-induced clearance in genotype 1 infected patients. These different studies showed the strong association and the importance of IL-28B polymorphisms in the treatment response. Combining the different genetic factors could improve their predictive value and help identify patients at a high risk of progression of fibrosis as well as those with a lower chance of responding to treatment. The aim of this review was to discuss the genomic factors (mRNAs, miRNAs, and SNPs) and HCV infection with clinical implications for either progression of fibrosis or treatment response. Recent findings on the IL-28B polymorphism and its application in clinical practice will also be discussed.

A single nucleotide polymorphism, rs129679860, in the IL28B locus is associated with the viral kinetics and a sustained virological response in a chronic, monoinfected hepatitis C virus genotype-1 Brazilian population treated with pegylated interferon-ribavirin

Single nucleotide polymorphisms (SNPs) in the interleukin (IL)28B locus have been associated with a sustained virological response (SVR) in interferon-ribavirin (IFN-RBV)-treated chronic hepatitis C virus (HCV)-infected patients in European and African populations. In this study, the genotype frequency of two IL28B SNPs (rs129679860 and rs8099917) in a cohort of chronic HCV-monoinfected patients in Brazil was evaluated and the SNP sufficient to predict the treatment response outcome was determined. A total of 66 naïve genotype-1 chronic HCV-infected patients were genotyped and the associated viral kinetics and SVR were assessed. The overall SVR was 38%. Both the viral kinetics and SVR were associated with rs129679860 genotypes (CC = 62% vs. CT = 33% vs. TT = 18%, p = 0.016). However, rs8099917 genotypes were only associated with SVR (TT = 53% vs. TG = 33% vs. GG = 18%; p = 0.032). In this population, the analysis of a single SNP, rs12979860, successfully predicts SVR in the IFN-RBV treatment of HCV.

Genome-wide association study identifies variants associated with progression of liver fibrosis from HCV infection

BACKGROUND & AIMS

Polymorphisms in IL28B were shown to affect clearance of hepatitis C virus (HCV) infection in genome-wide association (GWA) studies. Only a fraction of patients with chronic HCV infection develop liver fibrosis, a process that might also be affected by genetic factors. We performed a 2-stage GWA study of liver fibrosis progression related to HCV infection.

METHODS

We studied well-characterized HCV-infected patients of European descent who underwent liver biopsies before treatment. We defined various liver fibrosis phenotypes on the basis of METAVIR scores, with and without taking the duration of HCV infection into account. Our GWA analyses were conducted on a filtered primary cohort of 1161 patients using 780,650 single nucleotide polymorphisms (SNPs). We genotyped 96 SNPs with P values <5 × 10(-5) from an independent replication cohort of 962 patients. We then assessed the most interesting replicated SNPs using DNA samples collected from 219 patients who participated in separate GWA studies of HCV clearance.

RESULTS

In the combined cohort of 2342 HCV-infected patients, the SNPs rs16851720 (in the total sample) and rs4374383 (in patients who received blood transfusions) were associated with fibrosis progression (P(combined) = 8.9 × 10(-9) and 1.1 × 10(-9), respectively). The SNP rs16851720 is located within RNF7, which encodes an antioxidant that protects against apoptosis. The SNP rs4374383, together with another replicated SNP, rs9380516 (P(combined) = 5.4 × 10(-7)), were linked to the functionally related genes MERTK and TULP1, which encode factors involved in phagocytosis of apoptotic cells by macrophages.

CONCLUSIONS

Our GWA study identified several susceptibility loci for HCV-induced liver fibrosis; these were linked to genes that regulate apoptosis. Apoptotic control might therefore be involved in liver fibrosis.

Cellular and molecular mechanisms of hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor that accounts for ~80 % of all liver cancer cases worldwide. It is a multifactorial disease caused by a variety of risk factors and often develops in the background of underlying cirrhosis. A number of cellular phenomena, such as tumor microenvironment, inflammation, oxidative stress, and hypoxia act in concert with various molecular events to facilitate tumor initiation, progression, and metastasis. The emergence of microRNAs and molecular-targeted therapies adds a new dimension in our efforts to combat this deadly disease. Intense research in this multitude of areas has led to significant progress in our understanding of cellular processes and molecular mechanisms that occur during multistage events that lead to hepatocarcinogenesis. In this review, we discuss the current knowledge of HCC, focusing mainly on advances that have occurred during the past 5 years and on the development of novel therapeutics for liver cancer.

The impact of interferon lambda 3 gene polymorphism on natural course and treatment of hepatitis C

Host genetic factors may predict the outcome and treatment response in hepatitis C virus (HCV) infection. Very recently, three landmark genome-wide association studies identified single nucleotide polymorphisms near the interleukin 28B (IL28B) region which were more frequent in responders to treatment. IL28B encodes interferon (IFN)λ3, a type III IFN involved in host antiviral immunity. Favourable variants of the two most widely studied IL28B polymorphisms, rs12979860 and rs8099917, are strong pretreatment predictors of early viral clearance and sustained viral response in patients with genotype 1 HCV infection. Further investigations have implicated IL28B in the development of chronic HCV infection versus spontaneous resolution of acute infection and suggest that IL28B may be a key factor involved in host immunity against HCV. This paper presents an overview about the biological activity and clinical applications of IL28B, summarizing the available data on its impact on HCV infection. Moreover, the potential usefulness of IFNλ in the treatment and natural history of this disease is also discussed.

Roles of ITPA and IL28B genotypes in chronic hepatitis C patients treated with peginterferon plus ribavirin

It has been reported that inosine triphosphatase (ITPA) gene variants protect against ribavirin-induced anemia in patients treated for chronic hepatitis C. IL28B variants also influence the treatment response of peginterferon plus ribavirin treatment in these patients. In the present study, we examined how ITPA and IL28B genotypes have clinical impacts on treatment-induced hematotoxicities and treatment response in HCV-infected patients treated with peginterferon plus ribavirin. ITPA genotypes (rs1127354 and rs6051702) and IL28B genotype (rs8099917) were determined by TaqMan SNP assay. We compared clinical background, treatment course and treatment response in terms of these genotypes. Only IL28B rs8099917 major type could predict sustained virological response. ITPA rs1127354 major type leads to significantly greater ribavirin-induced anemia than ITPA rs1127354 minor type between days 0 and 84. We noticed that IL28B rs8099917 minor genotype was associated with higher reduction of neutrophils and platelets. ITPA rs1127354 is useful for the prediction of ribavirin-induced anemia in the early phase after the commencement of peginterferon plus ribavirin treatment and IL28B rs8099917 is useful for the prediction of sustained virological response. Use of the combination of these two genotypes could lead to safe and effective treatment of chronic hepatitis C patients.

Implications of PNPLA3 polymorphism in chronic hepatitis C patients receiving peginterferon plus ribavirin

BACKGROUND

Homozygosity for the PNPLA3 p.I148M polymorphism influences steatosis and fibrogenesis in chronic hepatitis C (CHC).

AIM

To evaluate the effect of p.148M/M on sustained virological response (SVR) and viral kinetics in patients who underwent antiviral therapy with peg-interferon and ribavirin, stratified according to viral genotype and fibrosis severity, and secondarily, the interaction with interleukin-28B ( IL28B ) genotype on liver damage.

METHODS

In this observational study, we considered 602 treatment-naïve consecutive patients from tertiary referral centres in Milan and Vienna [61% genotype 1 (G1), 30% advanced fibrosis, 33% IL28B rs12979860 CC].

RESULTS

The p.148M/M genotype, detected in 8% of patients, did not influence SVR in the overall series (P = 0.29), but it was associated with SVR (3/17, 17% vs. 56/121, 46%; P = 0.034) and complete early viral response (4/17, 23% vs. 68/121, 56%; P = 0.018) in G1/4 patients with advanced fibrosis. After adjustment for age, viral load, IL28B CC genotype, treatment dose, and steatosis, p.148M/M remained a predictor of SVR in G1/4 patients with advanced fibrosis (OR 0.23, 95% CI 0.04-0.87). The p.148M/M genotype was associated with more advanced fibrosis in the overall series (P = 0.049), whereas the rs12979860 IL28B CC genotype only in patients negative for p.148M/M (P = 0.017), independently of age, BMI and alanine transaminase levels (OR 1.51, 95% CI 1.01-2.27).

CONCLUSIONS

PNPLA3 p.148M/M genotype was negatively associated with SVR and early viral kinetics independently of steatosis, albeit only in difficult-to-cure G1/4 patients with advanced fibrosis, whereas stratification for the p.148M/M PNPLA3 genotype unmasked an association between IL28B CC genotype and more severe liver fibrosis.

Relation of IL28B gene polymorphism with biochemical and histological features in hepatitis C virus-induced liver disease

BACKGROUND/AIMS

Polymorphism at the IL28B gene may modify the course of hepatitis C virus (HCV) chronic infection. Our aim was to study the influence of IL28B rs12979860 gene polymorphism on the biochemistry and pathology of HCV-induced disease in the clinical course from mild chronic hepatitis C to hepatocellular carcinoma.

METHODS

We have determined the rs12979860 single nucleotide polymorphism (SNP) upstream IL28B gene in two groups of patients with HCV-induced chronic liver disease: 1) 268 patients (159 men) with biopsy-proven chronic hepatitis C, to analyse its relation with biochemical, virological and histological features; and 2) 134 patients (97 men) with HCV-related hepatocellular carcinoma. The distribution of the analysed SNP in hepatocellular carcinoma patients was compared with that found in untreated chronic hepatitis C patients. All patients were white and most were Spaniards.

RESULTS

In multivariate analysis ALT values were higher (P = 0.001) and GGT values were lower (P<0.001) in chronic hepatitis C patients homozygotes for the major rs12979860C allele as compared with carriers of the mutated rs12979860T allele. Steatosis was more frequent (Odds ratio = 1.764, 95% C.I. 1.053-2.955) and severe (P = 0.026) in carriers of the rs12979860T allele. No relation was found between the analysed SNP and METAVIR scores for necroinflammation and fibrosis, and there were no differences in the distribution of the analysed SNP between hepatocellular carcinoma and untreated chronic hepatitis C patients.

CONCLUSION

The IL28B rs12979860 polymorphism correlates with the biochemical activity and the presence and severity of liver steatosis in chronic hepatitis C.

Treatment of hepatitis C virus infection in adults and children: updated Swedish consensus recommendations

Swedish recommendations for the treatment of hepatitis C virus (HCV) infection were updated at a recent expert meeting. Therapy for acute HCV infection should be initiated if spontaneous resolution does not occur within 12 weeks. The recommended standard-of-care therapy for chronic HCV genotype 1 infection is an HCV protease inhibitor in combination with peginterferon (peg-IFN) and ribavirin. Treatment is strongly recommended in patients with bridging fibrosis and cirrhosis, whereas in patients with less advanced fibrosis, deferring therapy may be preferential in light of likely therapeutic improvements in the near future. Patients with chronic genotype 2/3 infection should generally be treated with peg-IFN and ribavirin for 24 weeks. In patients with a very rapid viral response (i.e. HCV RNA below 1000 IU/ml on day 7), or favourable baseline characteristics and undetectable HCV RNA week 4, treatment can be shortened to 12-16 weeks, provided that no dose reductions are needed.

IL28B genetic polymorphism testing in the era of direct acting antivirals therapy for chronic hepatitis C: ten years too late?

An association between variations at the IL28B gene locus and HCV clearance (spontaneous recovery or sustained virological response under pegylated interferon (PEG-IFN) and ribavirin (RBV) has been extensively described. In genotype 1-infected patients, the new direct antiviral agents (DAA) including the two approved protease inhibitors boceprevir and telaprevir, in association with the PEG-IFN/RBV combination is the new standard of care making it necessary to redefine the interest of the IL28B genotype in the decision to treat and how to treat genotype 1-infected patients. In treatment-naïve patients, IL28B status can certainly identify those with a high probability of achieving SVR with response guided therapy and probably in whom the duration of treatment can be markedly reduced. In experienced patients, the impact of IL28B genotypes is limited and cancelled by early viral kinetics. However, the decision to initiate or withhold therapy remains a clinical one. In summary, although it was a major milestone in the treatment of patients with PEG-IFN/RBV, IL28B polymorphism testing entered the clinical arena almost 10 years too late.