Genetic variation in Interleukin-28B predicts SVR in hepatitis C genotype 1 Argentine patients treated with PEG IFN and ribavirin

IL28B gene polymorphism rs12979860, but not rs8099917, contributes to the occurrence of chronic HCV infection in Uruguayan patients

BACKGROUND

Host single-nucleotide polymorphisms (SNPs) near the interleukin 28B (IL28B) locus are associated with sustained virological response to antiviral therapy and with spontaneous Hepatitis C Virus (HCV) clearance. Prevalence of these SNPs varies depending on ethnicity. The impact of IL28B SNPs in HCV-infected patients is currently unknown in Uruguay. Therefore, the aim of this study was to evaluate and compare the distribution of polymorphisms in the IL28B gene (rs12979860 and rs8099917) among HCV-infected patients and healthy individuals in Uruguay and thus assess their possible association with the establishment of HCV infection.

METHODS

DNA was recovered from 92 non-infected individuals and 78 HCV-infected patients and SNPs were determined by RFLP and allelic discrimination by real-time PCR.

RESULTS

The distribution of rs12979860 genotypes for the infected population was 29.5%-CC, 47.4%-CT and 23.1%-TT and for the control group 45.7%, 42.4% and 11.9%, respectively. Prevalence in both infected and uninfected individuals is similar to that reported in other countries with admixed populations. The distribution of rs8099917 genotypes for the infected population was 57.7%-TT, 27.2%-TG and 14.1%-GG and for the control group 60.9%, 33.7% and 5.4%, respectively. The comparison of rs12979860 genotype distribution between the two populations evidenced a higher prevalence of the favourable genotype (CC) in the uninfected control group (p < 0.05). Additionally, results generated using logistic regression analysis show that individuals carrying rs12979860-TT or CT genotypes have a higher likelihood of developing chronic hepatitis upon infection with HCV, when compared to CC carriers, considering rs8099917 genotype as constant.

CONCLUSION

Patients with HCV infection have a statistically significant lower prevalence of the favourable rs12979860 genotype when compared to uninfected individuals; therefore we can establish that only IL28B rs12979860-CT and TT genotypes seem to contribute to the occurrence of chronic HCV infection in the cohort of Uruguayan population studied. Considering that a trend towards a higher frequency of "good" response genotypes was observed in responder patients, we believe that IL28B rs12979860 genotyping could be a useful tool for predicting different therapies outcome, including in the DAA era.

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.

A genetic variant in the interleukin 28B gene as a major predictor for sustained virologic response in chronic hepatitis C virus infection

BACKGROUND AND AIMS

The IL28B single nucleotide polymorphism (SNP) rs12979860 is a major predictor of treatment outcomes in hepatitis C virus (HCV) infection, but its distribution widely varies among populations and ethnicities. We undertook this study to investigate the distribution of IL28B SNP rs12979860 in Mexican patients with HCV infection and to assess its usefulness in predicting response to pegylated interferon-alpha and ribavirin (PegIFN-α/RVB) therapy.

METHODS

Three hundred and fifty patients with chronic HCV infection were studied. The frequency of sustained virologic response (SVR), non-responders and relapses following a course of standard therapy was longitudinally assessed in 295 of these patients. IL28B SNP rs12979860 was genotyped from genomic DNA using real-time RT-PCR. The number needed to treat (NNT) to achieve a SVR was calculated.

RESULTS

Seventy six (22%) patients were CC homozygous, 210 (60%) were heterozygous and 64 (18%) showed TT homozygosity for the IL28B SNP rs12979860. After a standard course of PegIFN-α/RVB, 69% of patients with the CC genotype, 46% of the heterozygous group and 38% of those with the TT genotype (p = 0.001) achieved a SVR. Conversely, the percentage of non-responders was 15, 43, and 48% (p <0.0001), respectively. The NNT to achieve a SVR was strongly influenced by the IL28B rs12979860 genotype and ranged from 2-10.

CONCLUSIONS

The IL-28B rs12979860 CC genotype was found in 22% of Mexican patients chronically infected by HCV. Genotyping IL28B SNP rs12979860 is useful to predict the response to a standard regimen with PegIFN-α/RVB, especially in those infected with HCV genotype 1.

The role of interleukin-28b gene polymorphisms in chinese patients with chronic hepatitis C treated with pegylated interferon and ribavirin

BACKGROUND

Interleukin-28B (IL28B) single nucleotide polymorphism (SNP) rs8099917 has been described to be associated with response to treatment with pegylated interferon and ribavirin (PEG-IFN/RBV) in patients with chronic hepatitis C from the North America, Europe, Asia countries like Japan and Taiwan. Whether this holds true for Chinese patients remains unknown.

OBJECTIVES

We aimed to study the effects of IL28B rs8099917 on antiviral therapy responses in Chinese patients with hepatitis C.

PATIENTS AND METHODS

IL28B rs8099917 was genotyped in 263 patients with hepatitis C virus (HCV) infection and 244 healthy controls in Tianjin, China using TaqMan SNP genotyping method. The roles of rs8099917 and clinical characteristics in antiviral treatment were analyzed by logistic regression.

RESULTS

Among 263 patients with chronic HCV infection, 223 had a TT genotype (84.8%). Frequencies of TG/GG genotypes in patients with hepatitis C were significantly different from those of healthy controls (15.2% vs. 9.0%; P = 0.033). Patients with HCV infection had a higher G allele frequency than healthy controls (7.8% vs. 4.7%; P = 0.044). Univariate analysis revealed no significant association between rs8099917 and sustained virological response (SVR) (P = 0.612). However, it was found that HCV genotypes 2a/3a, age, prothrombin time (PT), albumin (ALB) and cholesterol (CHO) were associated with SVR. In multivariate analysis, only ALB was significantly an independent predictor of SVR (OR = 1.223; 95%CI: 1.046-1.430; P = 0.011).

CONCLUSIONS

In contrast with T, rs8099917 G is a susceptible allele to HCV in China. ALB can independently predict SVR. Rs8099917 may play a quiet role to predict treatment response of patients with hepatitis C who received PEG-IFN/RBV therapy in China.

The IFN-λ Genetic Polymorphism Association With the Viral Clearance Induced by Hepatitis C Virus Treatment in Pakistani Patients

BACKGROUND

Polymorphisms in the interferon λ (INF λ) genes on chromosome 19 have been associated with clearance of hepatitis C virus (HCV) induced by interferon and ribavirin therapy however there is no such data available for Pakistani patients with HCV infection.

OBJECTIVES

In this study, the effects of single nucleotide polymorphisms (SNPs) have been investigated in response to treatment with interferon-α and ribavirin in a cohort of 75 HCV genotype 3a patients.

PATIENTS AND METHODS

A total number of 50 SNPs from the Interferon λ region on chromosome 19 were genotyped to investigate allelic associations with the treatment response in HCV type 3a patients. Thirteen SNPs were associated with HCV clearance, with the most significant alleles being RS8109886 (Fisher's P = 0.0001), RS8113007 (Fisher's P = 0.0001) and RS12979860 (Fisher's P = 0.0002).

RESULTS

These SNPs were found to be the most suitable SNPs for predicting treatment response in the present study. These findings support those reported previously. This could be used to improve HCV treatment strategies and suggest that Pakistani patients should be genotyped for the relevant SNPs to identify the patients who are more likely to respond to interferon and ribavirin therapy.

CONCLUSIONS

This therapy is costly and can be accompanied by several adverse side-effects, hence pre-treatment prediction of patients who are most likely to benefit would have both economic and patient benefits in the long term.

The role of pharmacogenetics in the treatment of chronic hepatitis C infection

Hepatitis C virus (HCV) chronically infects 170 million people worldwide. Until recently, combination therapy with peginterferon-α (pegIFN) and ribavirin (RBV) has been the standard of care. However, for many patients, especially those infected with the most common HCV genotype 1 (HCV-1), this treatment has resulted in unsatisfactory treatment response rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. Genetic variation in the interleukin 28B (IL28B) gene is the major determinant of treatment response, a finding that has been replicated in multiple independent cohorts. This review focuses on the association between pharmacogenetics and conventional pegIFN/RBV therapy in patients infected with HCV non-genotype 1; patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. We also review the pharmacogenetic data for boceprevir and telaprevir triple therapy in patients with HCV-1 infection, as well as viral genomic polymorphisms and genetic variants that may protect against anemia. Pharmacogenetic information offers a personalized medicine approach to help clinicians and patients make better informed decisions to maximize response and minimize toxicity for the treatment of chronic HCV infection.

HBV genotype F: natural history and treatment

The analysis of the HBV genome revealed the existence of 10 genotypes, named A-J. Evidence of the influence of the different genotypes in the natural history and treatment response to nucleoside/nucleotide analogues or interferon-based regimens is scant. HBV genotype F is one of the most prevalent circulating genotypes in South America and the Arctic Circle. Since most of the available information on HBV is from Asia, the US and Europe, it reflects their predominant genotypes: A, B, C and D. To date, the evidence is not fully confirmed, but it appears that genotype F chronic hepatitis B is associated with a more aggressive course of liver disease, reflected by higher histological indexes, a higher risk of development of hepatocellular carcinoma and a higher rate of liver-related mortality. In terms of treatment response, the available data is, unfortunately, even more limited; however, what data is available suggests acceptable and similar response rates to pegylated interferon-α2a in genotype F compared to genotype A. Response rates to nucleoside/nucleotide analogues is not influenced by genotype. The review of this limited data sheds light on the necessity to conduct further studies in South America and the Arctic Circle in order to better understand the different aspects of HBV genotype F, especially in relation to treatment response.

Predictors of response to chronic hepatitis C treatment

Chronic hepatitis C is a growing health problem worldwide that has attracted increased attention in recent years. Treatment with peginterferon and ribavirin combination had previously been the standard of care. In 2011, a new treatment with protease inhibitors, telaprevir and boceprevir was approved, and a new standard of care was defined. Previous predictors of response have been redefined, and while IL28B, fibrosis stage and hepatitis C virus viral load testing continue to have their value, viral kinetics during treatment defining viral response have emerged as the strongest predictor for achieving sustained virologic response with the new treatment. New therapies are expected in the near future, and current treatment predictors of response may soon change.

Meta-analysis: IL28B polymorphisms predict sustained viral response in HCV patients treated with pegylated interferon-α and ribavirin

BACKGROUND

Interleukin (IL) 28B single nucleotide polymorphisms can predict sustained virological response (SVR) in hepatitis C virus (HCV) patients following pegylated interferon-alpha (PEG IFN-α) and ribavirin treatment.

AIM

To design a meta-analysis to determine IL28B genotypes', rs12979860 CC and rs8099917 TT, correlation with SVR in PEG IFN-α/ribavirin-treated HCV patients.

METHODS

Meta-analysis was performed in 17 studies of rs12979860 CC vs. CT/TT and 17 of rs8099917 TT vs. TG/GG. Odds ratios (OR) and confidence intervals (95% CI) were calculated by fixed- or random-effects models. Heterogeneity, sensitivity analysis and publication bias were also assessed.

RESULTS

Of 4252 Asian, Caucasian and African HCV patients analysed for rs12979860, SVR was more frequent in CC (vs. CT/TT; OR = 4.76, 95% CI: 3.15-7.20). Moreover, CC was associated with SVR for HCV genotype-1 or -4 infections (OR(genotype 1) = 5.52, 95% CI: 3.74-8.15; OR(genotype 4) = 8.11, 95% CI: 4.13-15.93), regardless of ethnicity. Of 4549 Caucasian and Asian HCV patients analysed for rs8099917, SVR was more frequent in TT (vs. TG/GG; OR = 3.31, 95% CI: 2.39-4.59). Moreover, TT was associated with SVR for HCV-1 (OR(genotype 1) = 4.28, 95% CI: 2.87-6.38). Rs8099917 TT predictive value was stronger in Asians (OR(Asians) = 8.09, 95% CI: 5.63-11.61; OR(Caucasians) = 3.00, 95% CI: 2.03-4.45). Ethnicity stratification revealed that rs8099917 TT had slight predictive value in Asian HCV-2/3 patients (OR = 1.99, 95% CI: 1.09-3.62).

CONCLUSIONS

IL28B rs12979860 CC and rs8099917 TT are strong SVR predictors for PEG IFN-α/ribavirin-treated HCV-1 patients, regardless of ethnicity. In HCV-2/3, rs12979860 CC has no SVR predictive value, but rs8099917 TT was slightly associated with SVR in Asians.