Combined effects of different interleukin-28B gene variants on the outcome of dual combination therapy in chronic hepatitis C virus type 1 infection

Association of IFNL3 rs12979860 and rs8099917 with biochemical predictors of interferon responsiveness in chronic hepatitis C virus infection

BACKGROUND & AIMS

Genetic variations near the interferon lambda 3 gene (IFNL3, IL28B) are the most powerful predictors for sustained virologic response (SVR) in patients with chronic hepatitis C virus (HCV) infection, compared to other biochemical or histological baseline parameters. We evaluated whether the interplay of both IFNL3 polymorphisms rs12979860 and rs8099917 together with non-genetic clinical factors contributes to the predictive role of these genetic variants.

METHODS

The cohort comprised 1,402 patients of European descent with chronic HCV type 1 infection. 1,298 patients received interferon-based antiviral therapy, and 719 (55%) achieved SVR. The IFNL3 polymorphisms were genotyped by polymerase chain reaction and melting curve analysis.

RESULTS

A significant correlation was found between the IFNL3 polymorphisms and biochemical as well as virologic predictors of treatment outcome such as ALT, GGT, cholesterol, and HCV RNA levels. In multivariate regression analysis, IFLN3 SNPs, HCV RNA levels, and the GGT/ALT ratio were independent predictors of SVR. Dependent on the GGT/ALT ratio and on the HCV RNA concentration, significant variations in the likelihood for achieving SVR were observed in both, carriers of the responder as well as non-responder alleles.

CONCLUSIONS

Our data support a clear association between IFNL3 genotypes and baseline parameters known to impact interferon responsiveness. Improved treatment outcome prediction was achieved when these predictors were considered in combination with the IFNL3 genotype.

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.

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.

Hepatitis C virus and lipids in the era of direct acting antivirals (DAAs)

The six different HCV-genotypes have marked differences in response to therapy with pegylated interferon-α and ribavirin. The introduction of the direct acting antiviral (DAA) protease inhibitors, telaprevir and boceprevir in combination with pegylated interferon-α and ribavirin has become the new standard of care for genotype 1 infection. Several host factors associated with response to pegylated interferon-α and ribavirin are not as important in predicting response to triple therapy, and yet low-density lipoprotein cholesterol (LDLC) and statin use remain important associations of outcome with DAAs. This review focuses on the clinical associations between lipids and treatment response to interferon based antiviral treatments. We consider how understanding the interactions of HCV and host lipid metabolism remains relevant in the era of DAAs for genotype 1 infection and for treatment of non-genotype 1 chronic hepatitis C.

Meta-analysis: implications of interleukin-28B polymorphisms in spontaneous and treatment-related clearance for patients with hepatitis C

BACKGROUND

Since 2009, several studies have identified single-nucleotide polymorphisms (SNPs) near the gene encoding for interleukin (IL)-28 (IL28B) that are strongly associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Because this large amount of data includes some inconsistencies, we consider assessment of the global estimate for each SNP to be essential.

METHODS

Relevant studies assessing IL28B polymorphisms associated with sustained virologic response (SVR) and spontaneous clearance (SC) were identified from a literature search of PubMed up to 9 July, 2012. Studies were eligible studies if they included patients infected with HCV or HCV/HIV, or assessed any SNP located within or near the IL28B gene, SVR data available under standard treatment, and/or SC data in patients with acute HCV infection. Pooled odds ratios were estimated by fixed or random effects models when appropriate. Variables such as HCV genotype, ethnicity, and type of co-infection were studied.

RESULTS

Of 282 screened studies, 67 were selected for SVR and 10 for SC. In total, 20,163 patients were studied for SVR and 3,554 for SC. For SVR, we found that all SNPs showed strong associations in patients with HCV genotypes 1 and 4, whereas the pooled ORs were almost three times lower for genotypes 2 and 3 (rs12979860 and rs8099917). Regarding ethnicity, the SNP most associated with SVR was rs12979860 in white patients, whereas in East Asians it seemed to be rs8099917. The most studied SNP (rs12979860) showed similar results for patients co-infected with HCV/HIV, as for those infected with HCV only. Finally, rs12979860 and rs8099917 both appeared to be associated with SC.

CONCLUSIONS

IL28B polymorphisms influence both the outcome of interferon treatment and the natural clearance of HCV. However we did not identify a universal predictor SNP, as the best genetic markers differed depending on patient ethnicity, genotype, and type of infection. Nevertheless, our results may be useful for more precise treatment decision-making.

A variant upstream of IFNL3 (IL28B) creating a new interferon gene IFNL4 is associated with impaired clearance of hepatitis C virus

Chronic infection with hepatitis C virus (HCV) is a common cause of liver cirrhosis and cancer. We performed RNA sequencing in primary human hepatocytes activated with synthetic double-stranded RNA to mimic HCV infection. Upstream of IFNL3 (IL28B) on chromosome 19q13.13, we discovered a new transiently induced region that harbors a dinucleotide variant ss469415590 (TT or ΔG), which is in high linkage disequilibrium with rs12979860, a genetic marker strongly associated with HCV clearance. ss469415590[ΔG] is a frameshift variant that creates a novel gene, designated IFNL4, encoding the interferon-λ4 protein (IFNL4), which is moderately similar to IFNL3. Compared to rs12979860, ss469415590 is more strongly associated with HCV clearance in individuals of African ancestry, although it provides comparable information in Europeans and Asians. Transient overexpression of IFNL4 in a hepatoma cell line induced STAT1 and STAT2 phosphorylation and the expression of interferon-stimulated genes. Our findings provide new insights into the genetic regulation of HCV clearance and its clinical management.

Genetic polymorphism of IL28B in hepatitis C-infected haemophilia patients in Israel

Single-nucleotide polymorphisms (SNPs) near the IL28B gene were identified as major predictors of treatment response (sustained virologic response--SVR) and spontaneous clearance of HCV. Haemophilia patients have the highest prevalence of HCV, and are a unique target for genetic studies. The Israeli population is ethnically heterogeneous; therefore, genetic variability is anticipated. To determine the IL28B haplotypes in HCV-infected haemophilia patients and association with SVR and spontaneous viral clearance. IL28B polymorphism at SNPs rs12979860 and rs8099917 was determined in sera obtained from 130 HCV-infected haemophilia patients. The frequency of the various haplotypes was analysed according to treatment response, spontaneous HCV clearance, viral load and degree of fibrosis. The CC haplotype at SNP rs12979860 was found in 31% of patients, whereas the TT genotype at SNP rs8099917 was detected in 57% of cases. SVR was achieved in 70% of patients carrying the CC haplotype (P = 0.0196 vs. CT/TT), and 50% of the TT genotype at SNP rs8099917 (P = 0.0227 vs. TG/GG). Thirty-five percent of patients carrying the CC haplotype and 26% with the TT genotype at SNP rs8099917 showed spontaneous clearance of HCV infection (P = 0.00262 vs. CT/TT; and P = 0.00371 vs. TG/GG respectively). The C-allele frequency was exceptionally high (71%) in immigrants from the Asian republics of Russia. In HCV-infected haemophilia patients, SVR was more commonly achieved among patients who had the CC (rs12979860) or TT (rs8099917) genotype. Likewise, patients who possess harbour the CC or TT genotypes were more likely to clear HCV infection spontaneously. A unique distribution of the CC genotype was observed in some ethnic groups.

Pharmacogenomics of hepatitis C infections: personalizing therapy

It is a widely held view that drug response genes have not proved as useful in clinical practice as anticipated at the start of the genomic era. An exception is in the treatment for chronic hepatitis C virus (HCV) genotype 1 infection with pegylated interferon α and ribavirin. In 2009, four independent genome-wide analyses identified IL28B polymorphisms that predict drug response in chronic hepatitis C (CHC). This discovery had immediate clinical impact. First, the IL28B genotype could be used to personalize therapy. In the 2 years since discovery, most of the more than 100,000 CHC patients commencing therapy for CHC in the West will have considered IL28B genotype testing. Second, the discovery has supported clinical trials for the use of the protein encoded by the gene known as interferon lambda. Third, it is expected that new insights into HCV pathogenesis will follow from studies of how IL28B affects HCV viral clearance and, ultimately, this will lead to new therapeutic strategies for CHC. This review discusses how IL28B genotyping is now used in personalizing therapy and, with the dramatically changing clinical landscape in CHC, with the advent of direct-acting antivirals, the prospects ahead.

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.

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.

Association of three SNPs in interleukin-28B with graft hepatic dysfunction after liver transplantation in Chinese Han population

BACKGROUND

Recurrent graft infection limited the effect of LT, early recognition and prophylaxis of HBV recurrence are very important, and interleukin 28B (IL‐28B) gene was reported to be associated with HBV infection.

AIMS

To explore the association between IL-28B single-nucleotide polymorphisms (SNPs) and graft re-infection after liver transplantation(LT).

METHODS

21 recipients with hepatitis B virus(HBV) recurrence and 157 recipients without HBV recurrence were included. We studied three SNPs in the promoter region of IL-28B gene at the positions rs12979860,rs12980275 and rs8099917 by HRM analysis (high-resolution melting curve analysis).

RESULTS

Hepatic allograft dysfunction was more likely to be associated with IL-28B SNPs. However, there was no significant difference in the frequencies of IL-28B gene distribution in recipients with or without HBV recurrence.

CONCLUSION

IL-28B gene polymorphism may be associated with the prognosis of LT recipients but it needs more experiments.

Factors that predict response of patients with hepatitis C virus infection to boceprevir

BACKGROUND & AIMS

Little is known about factors associated with a sustained virologic response (SVR) among patients with hepatitis C virus (HCV) infection to treatment with protease inhibitors.

METHODS

Previously untreated patients (from the Serine Protease Inhibitor Therapy 2 [SPRINT-2] trial) and those who did not respond to prior therapy (from the Retreatment with HCV Serine Protease Inhibitor Boceprevir and PegIntron/Rebetol 2 [RESPOND-2] trial) received either a combination of peginterferon and ribavirin for 48 weeks or boceprevir, peginterferon, and ribavirin (triple therapy) after 4 weeks of peginterferon and ribavirin (total treatment duration, 28-48 wk). A good response to interferon was defined as a ≥ 1 log(10) decrease in HCV RNA at week 4; a poor response was defined as a <1 log(10) decrease. We used multivariate regression analyses to identify baseline factors of the host (including the polymorphism interleukin [IL]-28B rs12979860) associated with response. The polymorphism IL-28B rs8099917 also was assessed.

RESULTS

In the SPRINT-2 trial, factors that predicted a SVR to triple therapy included low viral load (odds ratio [OR], 11.6), IL-28B genotype (rs 12979860 CC vs TT and CT; ORs, 2.6 and 2.1, respectively), absence of cirrhosis (OR, 4.3), HCV subtype 1b (OR, 2.0), and non-black race (OR, 2.0). In the RESPOND-2 trial, the only factor significantly associated with a SVR was previous relapse, compared with previous nonresponse (OR, 2.6). Most patients with rs12979860 CC who received triple therapy had undetectable levels of HCV RNA by week 8 (76%-89%), and were eligible for shortened therapy. In both studies, IL-28B rs12979860 CC was associated more strongly with a good response to interferon than other baseline factors; however, a ≥ 1 log(10) decrease in HCV-RNA level at week 4 was associated more strongly with SVR than IL-28B rs12979860. Combining the rs8099917 and rs12979860 genotypes does not increase the association with SVR.

CONCLUSIONS

The CC polymorphism at IL-28B rs12979860 is associated with response to triple therapy and can identify candidates for shorter treatment durations. A ≥ 1 log(10) decrease in HCV RNA at week 4 of therapy is the strongest predictor of a SVR, regardless of polymorphisms in IL-28B.

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.

Early anemia and rapid virological response improve the predictive efficiency of IL28B-genotype for treatment outcome to antiviral combination therapy in patients infected with chronic HCV genotype 1

IL28B genotypes and virological response within 4 weeks are predictors of sustained virological response in patients infected with chronic hepatitis C virus (HCV) genotype 1 treated with antiviral dual combination therapy. The predictive value of "early" anemia (within 4 weeks) alone or in combination with the two other predictors has not been studied yet. A total of 305 pegylated interferon-α and ribavirin-treated patients with HCV genotype 1 were included in this study. Hemoglobin values at week 0, 4, 8, and 12 as well as the predictive efficiency of early anemia (hemoglobin value below the gender-specific lower limit: female < 11.5; male < 13.5 g/dl) during therapy were assessed with IL28B genotypes and rapid virological response. Forty-eight percent of treated patients developed early anemia. In both females and males (64%), a decrease of hemoglobin concentration of 3 g/dl (female: 14.7 ± 1.1 to 11.4 ± 1.3; male: 15.2 ± 1.2 to 12.2 ± 1.5) significantly correlated with sustained virological response. 64% of IL28B-CC patients showed a sustained virological response. Seventy-eight percent of patients with rapid virological response definitively eliminated the virus. Early anemia (81:48:41%) and rapid virological response (83:91:92%) increased the predictive efficiency of IL28B rs12979860 genotype distribution (CC:CT:TT). IL28B-CC and early anemia as well as IL28B-CC and rapid virological response had an Odds ratio of 42.4 or 75 to achieve a sustained virological response compared to TT without early anemia or rapid virological response. This finding may help to early identify responders to standard PEG-IFN-α and ribavirin treatment even within those with unfavorable IL28B genotype.