The role of genetic markers in hepatitis C virus therapy: a major step for individualized care

Correlation between interleukin-28 gene polymorphism with interleukin-28 cytokine levels and viral genotypes among HCV patients in Yazd, Iran

OBJECTIVES

Recent studies using genome-wide association studies (GWAS) have shown the strong association between polymorphisms near the interleukin-28B (IL-28B) gene and spontaneous clearance of hepatitis C virus (HCV). The present study was designed to evaluate the association of interleukin-28 gene polymorphism with interleukin-28 cytokine levels in different viral genotypes among HCV patients in Yazd, Iran.

RESULT

The most prevalent genotype in chronic cases was genotype 3a, and the lowest one was 2/3a. There were statistically significant differences in genotype frequency between the two studied groups for IL-28B rs12979860C/T. The frequency of CC genotype of IL-28B at rs12979860 SNP was higher in spontaneously cleared patients in comparison with chronic HCV patients. Significant association was found when serum levels of IL28B were compared to various IL-28 genotypes. There was a significant difference between IL-28 polymorphism and HCV genotypes (p = 0.003).

Association of interferon gamma gene polymorphism and susceptibility to hepatitis C virus infection in Egyptian patients: A multicenter, family-based study

Background and Aim

Polymorphisms in some genes may influence the persistence of hepatitis C virus (HCV) infection, clinical outcome, HCV replication, and liver damage. This study was conducted to investigate the role of the interferon gamma (IFN‐γ) gene at (+874 T/A, −764 G/C, −179 C/A) single‐nucleotide polymorphisms (SNPs) and its receptor (IFN‐γR2) at (rs 2786067 A/C) SNP in the susceptibility of Egyptian families to HCV infection with high‐resolution techniques.

Methods

In total, 517 Egyptian families, with 2246 subjects, were recruited to this study from the Upper and Lower Egypt governorates and were classified into three groups: 1034 patients with chronic hepatitis C virus, 108 subjects with spontaneous virus clearance (SVC), and 1104 subjects as a healthy control group. All subjects were genotyped for (+874 T/A, rs2430561, −764 G/C, rs2069707, −179 C/A, rs2069709, and rs 27860067, A/C) SNPs of the IFN‐γ gene using the allelic discrimination real‐time polymerase chain reaction technique and were confirmed using sequence‐based typing.

Results

The carriage of T allele of (+874) IFN‐γ is a risky allele and was significantly higher in chronic hepatitis C more than other two groups (odds ratio [OR]: 2.6646, P < 0.0002). On the other hand, the C allele of (−764, rs2069707) is a protective allele and was higher in SVC than the other two groups (OR: 0.2709, P < 0.0001). However, both (−179 C/A, rs 2069709) and (rs 27860067, A/C) SNPs are not polymorphic enough to be studied in the Egyptian population.

Conclusions

HCV infection is associated with the T allele of (+874 rs2430561), while SVC of HCV is associated with the C allele of (−764, rs2069707) of the IFN‐γ gene.

The complete title: The effect of interleukin-28B rs12979860 polymorphism on the therapeutic response of Moroccan patients with chronic hepatitis C

BACKGROUND/AIMS

There is increasing evidence for the effect of rs12979860 IL28B polymorphism in response to the standard treatment PEG-IFN/RBV (i.e. combination of pegylated interferon and ribavirin) in chronic hepatitis C virus (HCV) infection. The present study aimed to determine the impact of IL28B associations in interferon responsiveness in 187 Moroccan patients with chronic HCV infection.

METHODS

HCV RNA levels were measured with a real-time RT-PCR assay and treatment efficacy was assessed by sustained virological response (SVR) and patients were classified as responders or non-responders. IL28B rs12979860 polymorphism genotyping was achieved by PCR-HRM technique.

RESULTS

The results demonstrated that SVR was achieved in 102 patients (55%); while 69 were non-responders (37%) and 16 relapsed (8%). Genotype 1 was the predominant HCV genotype detected in 112 patients followed by genotype 2 in 56 patients. The genotype CC was observed in 42 cases (25%); CT in 69 (41%) and TT in 57 (34%) demonstrating a C allele frequency of 46%. The SVR was observed in 32 patients with genotype CC accounting for 76%. The frequencies of rs12979860 CC type in infected individuals with HCV genotype 1 were 47% and 12% respectively in SVR and non-SVR groups. A highly statistically significant association between this SNP and SVR was found (p<0.001). Using multivariate logistic regression analysis, CC genotype was an independent factor for SVR. In the group of patients infected with genotype 2, SVR rate was 79%. The frequency of rs12979860 CC type in SVR group (n=4) was 9% and rs12979860 non-CC genotype was highly associated with SVR (p=0.001).

CONCLUSION

This finding adds evidence that genotyping for the IL-28B rs12979860 SNP can be a good parameter for the prediction of treatment success in patients with chronic hepatitis C before initiation of antiviral therapy in Morocco.

Characterization of the Interleukin-28B Gene rs12979860 C/T Polymorphism in Turkish Chronic Hepatitis C Patients and Healthy Individuals

BACKGROUND

Host genetic factors can affect the progress of hepatitis-C virus (HCV) infection. Interleukin-28B (IL28B) single nucleotide polymorphisms may play an important role in the clearance of HCV spontaneously or with treatment.

AIMS

The aim of our study was to evaluate the rate of IL28B genotypes in patients with Chronic Hepatitis-C (CHC) and healthy control subjects and to examine the characteristics of patients in each IL28B subgroup.

STUDY DESIGN

Case-control study.

METHODS

IL28B polymorphisms were genotyped by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) in all subjects.

RESULTS

The mean age was 52.3±10.9 years (33% female) in the CHC patients and 52.5±11.5 years (39.1% female) in the healthy controls. The percentage of patients with a high baseline viral load (≥400,000 IU/mL) was higher in the CT group (69.8%) compared to the C/C (44.4%) and T/T (50%) groups (p=0.021). There was no significant difference in liver fibrosis and liver necroinflammation distribution among the CC, CT and TT genotypes with mild, moderate and severe groups (p=0.058 and p=0.791, respectively). Mean age, gender ratio, body mass index, viral load at baseline, rate of HCV genotypes, baseline ALT levels were not significantly different among the three IL28B subgroups (p>0.05). A significant increase was observed in the frequencies of IL28B rs12979860 TT genotypes in the CHC patients (20.6%) compared to the healthy control group (8.7%) (p=0.033).

CONCLUSION

In the patients with chronic HCV-genotype 1b and 4 infections, the IL28B rs12979860 (C>T) gene polymorphism frequency of the TT genotype and T allele was higher than in healthy control subjects. This result indicates that the TT genotype may be more effective in the progression of HCV infection than other genotypes.

Genetic variant of IL28B rs12979860, as predictive marker of interferon-based therapy in Pakistani population

Hepatitis C virus (HCV) genotypes and genetic variants of interleukin 28B (IL28B) are significantly associated with interferon plus ribavirin treatment of HCV infection. We investigated the distribution of HCV genotypes and single-nucleotide polymorphisms (SNPs) of IL28B (rs12979860 and rs8099917) in Pakistani population. IL28B genotyping was performed by allele-specific PCR and restriction fragment length polymorphism PCR in 140 chronic hepatitis C patients (CHC) and 120 healthy controls. HCV genotype 3 (HCVG3) was the most prevalent genotype, 71.4% (n = 100/140) and with the highest treatment response of 90% (n = 90/100). The overall treatment response of all the HCV genotypes was 82% (n = 115/140). The distribution of IL28B rs12979860CC genotype in treatment responder and non-responder groups was 40.8% (n = 47/115) and 16% (n = 4/25) respectively. IL28B rs12979860CC genotype demonstrated a significant correlation (p = 0.019) with interferon-based therapy of HCV infection. However, there was no observed association of IL28B rs8099917 polymorphism with treatment response in CHC patients (p = 0.264). In conclusion, HCV genotypes and IL28B rs12979860 are predictive markers for the efficiency of interferon plus ribavirin combinational therapy of HCV infection. We recommend the inclusion of testing for these markers in the clinical criteria for decision making for HCV therapy in Pakistani population.

Meta-analysis: superior treatment response in Asian patients with hepatitis C virus genotype 6 versus genotype 1 with pegylated interferon and ribavirin

OBJECTIVE

Our goal was to systematically and quantitatively assess treatment response between Asian patients with hepatitis C virus genotype 6 (HCV-6) and hepatitis C virus genotype 1 (HCV-1) treated for 48 weeks with pegylated interferon and ribavirin.

METHODS

We performed a literature search in MEDLINE and EMBASE for 'genotype 6' in August 2013. Additional abstracts from major international scientific conferences from 2012 to 2013 were reviewed. Studies included were original articles with ≥10 treatment-naïve Asian HCV-6 patients. Exclusion criteria were coinfections with hepatitis B virus, HIV and/or other liver diseases. Heterogeneity was defined as a Cochrane Q test with a p value of 0.10 and an I(2) statistic of >50%. RESULTS of a random-effects model are reported.

RESULTS

A total of 1,046 (503 HCV-6; 543 HCV-1) patients from 12 studies were included in the analysis. The pooled sustained virologic response (SVR) rate was 80.2% (95% CI 74.3-85.0, Q statistic = 20.87, p < 0.035; I(2) = 47.3%) for HCV-6 and 62.5% (95% CI 41.9-79.4, Q statistic = 52.41, p < 0.001; I(2) = 92.37) for HCV-1 patients. HCV-6 patients had a significantly higher SVR rate compared to HCV-1 patients (odds ratio 2.73, 95% CI 1.69-4.41, p < 0.001). Approximately one fourth of patients without early virologic response (EVR) achieved SVR, regardless of genotype (HCV-1, n = 6/23; HCV-6, n = 4/21).

CONCLUSIONS

Asian patients with HCV-6 can expect higher SVR rates (∼80%) than HCV-1 patients (∼63%). EVR as a stopping rule is less clear in Asian patients with HCV-6 and HCV-1.

Impact of Interleukin 28B Genotype on the Virological Responses in Chronic Hepatitis C Treatment

Background

Interleukin (IL) 28B single nucleotide polymorphisms may play a role in the clearance of hepatitis C virus (HCV). We aimed to evaluate the treatment response of chronic HCV infection patients to pegile interferon (pegIFN) and ribavirin treatment with regard to IL28B rs12979860 C/T polymorphism.

Methods

A total of 186 patients (mean age, 55.6 ± 10 years; 65.1% female) who underwent pegIFN and ribavirin treatment for chronic HCV infection were studied. We analyzed demographics, HCV genotype, baseline alanine aminotransferase (ALT) levels, histopathological data, viral load before treatment and at 4, 12, 24, 48, and 72 weeks from the treatment start, and IL28B genotype. IL28B polymorphism was genotyped using polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP) in all the subjects.

Results

One hundred forty-five (86.8%) patients were infected with viral genotype 1b, and 13.2% were infected with viral genotype 4. The rates of C/C, C/T, and T/T genotypes were 22.6%, 52.7%, and 24.7% respectively. The percentage of patients with a viral load over 400,000 IU/mL was higher in the C/T group (P = 0.020). Of the patients, 44.6% provided sustained virological response (SVR) to pegIFN and ribavirin combination treatment. The frequency of T allele was 41% in patients with SVR, whereas 59% patients provided no response (P < 0.001). SVR was obtained in 66.7%, 42.9%, and 28.3% of CC, CT, and TT groups (P = 0.001). The rates of rapid virological response (RVR), early virological response (EVR), end-of-treatment response (ETR), and SVR were higher in the CC group than other groups (P = 0.216, P < 0.001, P = 0.001, P = 0.001, respectively). The relapse and null response (NR) rates were higher in TT group and partial response rate (PR) was higher in CT group.

Conclusions

IL28B rs12979860 C/T gene polymorphism affects the response to antiviral treatment in the patients with chronic HCV genotypes 1b and 4 infections.

Meta-analysis of patients with hepatitis C virus genotype 6: 48 weeks with pegylated interferon and ribavirin is superior to 24 weeks

BACKGROUND

Hepatitis C virus genotype 6 (HCV-6) is common in patients from Southeast Asia and the surrounding regions. Optimal treatment duration for HCV-6 is unknown given the inconclusive evidence from studies with varying methodologies and small sample sizes.

METHODS

A literature search for 'genotype 6' in MEDLINE and EMBASE in October 2013 produced 161 and 251 articles, respectively. Additional abstracts were identified from four major international GI/liver conferences in 2012/2013. Inclusion criteria were original studies with ≥10 HCV-6 treatment-naïve patients treated with pegylated interferon + ribavirin (PEG IFN+RBV). Exclusion criteria were coinfections with HBV, HIV, other HCV genotypes, and/or other liver diseases. Primary outcome was pooled sustained virologic response (SVR). Heterogeneity was defined by Cochrane Q test (p value of 0.10) and I (2) statistic (≥50 %).

RESULTS

A total of 13 studies with 641 patients were included. The pooled SVR estimate was 77 % (CI 70-83 %) (Q value = 38.4, p value <0.001, I (2) = 68.7 %) overall, 79 % (CI 73-84 %) for the 48-week group and 59 % (CI 46-70 %) for 24-week group, respectively. In studies with direct comparison of the two groups, SVR was superior in patients treated for 48 versus 24 weeks, OR 1.9 (CI 1.08-3.2, p = 0.026). In studies with direct comparison of patients with rapid virologic response (RVR), there was no difference in SVR between 48 versus 24 weeks, OR 1.74 (CI 0.65-4.64, p = 0.27).

CONCLUSION

Hepatitis C virus genotype 6 patients should be treated for 48 weeks, and those who achieve RVR may receive the shorter 24-week treatment duration. The high SVR (~80 %) with 48 weeks of PEG IFN+RBV therapy may be a cost-effective option for HCV-6 patients from resource-poor regions.

Mysterious Linkages Between Hepatitis C Virus Genotypes, Interleukin-28B Genotypes and Viral Clearance- A Meta-Analysis

BACKGROUND

Recent genome wide association studies (GWAS) have shown important roles of single nucleotide polymorphisms (SNP) near region of interleukin B 28 (IL28B) gene in spontaneous and drug-induced clearance of hepatitis C virus (HCV) in genotype 1 HCV infection.

OBJECTIVES

This meta-analysis was designed to determine the world-wide distribution patterns of IL28B genotypes and alleles, and to find possible linkages between IL28B and HCV genotypes.

PATIENTS AND METHODS

Manual and electronic databases were searched. Critical appraisal was performed. According to the results of heterogeneity tests, we used fix/random model for the analysis. The data concerning patients' ethnicity and HCV genotypes were analyzed by using statistical analysis software.

RESULTS

A total of 255 articles were found. After article review and quality assessment, 50 studies, including 18662 patients and 1313 healthy subjects, were analyzed. Presence of HCV genotype 3 versus genotype 1 was significantly associated with a higher frequency of CC genotype and C allele, with an odds ratio (OR) of 1.68 (95% CI: 1.44-1.99) and 1.49 (95% CI: 1.33-1.67), respectively. Prevalence of the rs12979860 CC genotype among genotype 1 HCV infected patients of Asian ethnicity was 69.48% (95% CI: 65.20-73.77), which was significantly higher than its prevalence [33.27% (95% CI: 28.88-37.67)] in the Caucasian genotype 1 HCV infected patients. Prevalence of rs12979860 TT genotype in the African-American genotype 1 HCV infected patients was the highest [36.20% (95% CI: 32.91-39.49)], and significantly different compared to all other ethnicities.

CONCLUSIONS

There were significant linkages between HCV genotypes and IL28B genotypes/alleles. Patients with a favorable IL28B and genotypes 1 and 4 HCV infection stand a better chance to clear HCV in the acute phase.

Host genetic variants in obesity-related nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a complex disease. The considerable variability in the natural history of the disease suggests an important role for genetic variants in the disease development and progression. There is evidence based on genome-wide association studies and/or candidate gene studies that genetic polymorphisms underlying insulin signaling, lipid metabolism, oxidative stress, fibrogenesis, and inflammation can predispose individuals to NAFLD. This review highlights some of the genetic variants in NAFLD.

Estimates of HCV-1 patients attaining RVR following dual therapy with peg-interferon and ribavirin

BACKGROUND

Given the significant side-effects and healthcare costs associated with telaprevir- or boceprevir-combination therapy, identifying patients likely to respond to dual therapy peg-interferon (Peg-IFN)/ribavirin is highly desirable. Since the perception of how large the pool of patients who may achieve rapid virologic response (RVR) is vaguely ascertained, we searched the literature for this information.

METHODS

Studies on patients treated with Peg-IFN/ribavirin were identified by searching MEDLINE and analyzed by meta-analysis. The primary end point was weighted estimates of RVR. The influence on race/ethnicity, baseline viremia, type of Peg-IFN, ribavirin dosage, and significant hepatic fibrosis on the results was evaluated.

RESULTS

Across 38 studies on 13,219 patients, the fraction of RVR patients was 19.6 %. The only baseline factor influencing RVR was race/ethnicity, with higher rates in Asian (26.7 %) and Caucasian patients (22.5 %). Of the 1,735 RVR patients, 85.1 % attained sustained virologic response (SVR). In these, SVR was influenced by ribavirin dose (86.8 vs. 72.8 % for high or low), type of Peg-IFN (91.8 % for alpha-2b vs. 82.9 % for alpha-2a), and treatment duration (91.7 % for 48 weeks vs. 79.4 % for 24 weeks).

CONCLUSIONS

One fifth to one fourth of hepatitis C virus genotype 1 (HCV-1) patients can be safely treated with dual therapy of Peg-IFN/ribavirin, and may be spared from cost and inconvenience of regimens considering the addition of HCV protease inhibitors.

Role of interleukin-28B polymorphism as a predictor of sustained virological response in patients with chronic hepatitis C treated with triple therapy: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Chronic hepatitis C represents an important health problem. The aim of our meta-analysis was to establish the role of reference single nucleotide (rs) 12979860 allele of interleukin-28B (IL28B) CC versus CT+TT genotype (the most researched allele of IL28B) as a predictor of sustained virological response (SVR) in patients with chronic hepatitis C treated with triple therapy.

METHODS

The PubMed, MEDLINE, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases as well as abstract books from important gastroenterology and hepatology meetings were searched for all studies published until 15 July 2012 that analysed the relationship between the polymorphism of IL28B and SVR in patients with chronic hepatitis C, genotype 1, treated with pegylated interferon + ribavirin + direct antiviral agents (telaprevir or boceprevir). The following keywords were used: IL28B polymorphism, chronic hepatitis C, sustained virological response, SVR, triple therapy, telaprevir, boceprevir.

RESULTS

Odds ratios (ORs) with 95 % confidence intervals were pooled from five study populations (1,641 cases) using a random-effects model. The SVR rate was significantly higher in patients with the CC genotype of IL28B than in those with non-CC genotypes (CT and TT): OR = 3.91 (95 % CI 2.11-7.28), p < 0.0001. Higher SVR rates were obtained in chronic hepatitis C patients with the CC genotype of IL28B, regardless of their therapeutic status (naïve patients: OR = 3.99 [95 % CI 1.67-9.51], p < 0.0001; and previously treated ones: OR = 2.15 [95 % CI 1.35-3.43], p = 0.001).

CONCLUSION

IL28B polymorphism seems to influence the SVR rate in patients with chronic hepatitis C treated with triple therapy, but further studies are needed to clarify the mechanism and the influence of other factors on the SVR rates.

Value of IL28B genotyping in patients with HCV-related mixed cryoglobulinemia: results of a large, prospective study

HCV-related mixed cryoglobulinemia (MC) is characterized by clonal expansion of B cells producing a polyreactive natural antibody (rheumatoid factor) and interferon (IFN)-based therapy is the first therapeutic option in mild-moderate MC. Single nucleotide polymorphisms (SNPs) proximal to genes involved in the innate response (IL28B/IFN-λ gene family) are strongly associated with spontaneous and IFN-induced viral clearance in hepatitis C, but no data exist about their role in HCV-positive MC. A large cohort of patients with HCV and MC was studied to evaluate the influence of IL28B genotype on the response to treatment and/or the evolution to MC of HCV infection. The rs12979860/rs8099917 IL28B polymorphisms were analysed in 481 consecutive HCV-positive subjects (250 with MC and 231 without MC, as controls) using real-time PCR and direct sequencing. Hundred and fifteen HCV patients with MC received standard anti-HCV therapy, and the results were evaluated according to the IL28B SNP distribution. Similar IL28B SNPs allele frequencies were recorded for patients and controls. IL28B major allele homozygosis (for both SNPs tested) was tightly correlated with virological and clinical response (P = 0.002). A statistically significant association was limited to 'difficult-to-treat' (G1/4) HCV genotypes. The IL28B genotype was a strong independent predictor of response (P = 0.007, OR 6.06; CI 1.65-22.22). The IL28B genotype was confirmed to be a useful predictor of response to IFN-based therapy in patients with HCV and MC. The very close correlation between IL28B SNP distribution, virological and clinical response definitively confirmed the key role played by HCV in MC. Conversely, the IL28B genotype does not seem to influence the evolution to MC.

An association study of functional polymorphic genes IRF-1, IFNGR-1, and IFN-γ with disease progression, aspartate aminotransferase, alanine aminotransferase, and viral load in chronic hepatitis B and C

BACKGROUND

Investigational approaches based on genome-wide association studies have proven useful in identifying genetic predictors for many diseases, including susceptibility to chronic hepatitis B and C. In these studies, the majority of genetic variants that have shown a positive association have been identified in genes involved in the immune response. In this study IFN-γ, IFNGR-1, and IRF-1 genes were analyzed for their role in susceptibility to the development of chronic hepatitis B and chronic hepatitis C in a Turkish population.

METHODS

Polymorphic genes IRF-1 (-410, -388), IFNGR-1 (-56, -611), and IFN-γ (+874) were analyzed in a total of 400 individuals: 100 chronic hepatitis B patients, 100 hepatitis B carriers, 100 chronic hepatitis C patients, and 100 healthy controls. A single base primer extension assay was used. Correlations between genes and gender, viral load, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were also investigated.

RESULTS

The IRF-1 gene at positions -388 and -410 were observed to be candidate gene markers for susceptibility to the development of chronic hepatitis B and C (p<0.05). IFN-γ +874 and IFNGR-1 (-56 and -611) correlated with chronic hepatitis B but not chronic hepatitis C. Correlation of functional genotype with viral load and AST and ALT levels revealed an association of IFN-γ +874 and IFNGR-1 -611 with chronic hepatitis C and IFN-γ +874 with viral load and chronic hepatitis B (p<0.05).

CONCLUSIONS

Findings suggest that IFN-γ (+874), IRF-1 (-410, -388), and IFNGR-1 (-56, -611) are candidate gene markers for determining patient susceptibility to the development of chronic hepatitis B and C.

Distribution of IL28B Genotypes in Iranian Patients with Chronic Hepatitis C and Healthy Individuals

BACKGROUND

IL28B polymorphism is recognized as one of the most prominent predictors of hepatitis C spontaneous and treatment-induced clearance. Interestingly, the favorable genotypes of IL28B are found to be more frequent in Asian ethnicity than Caucasian and African populations, respectively. A few studies reported that there is a mysterious association between the IL28B polymorphism and the hepatitis C virus (HCV) genotype in patients with chronic hepatitis C but they did not give any reason for this phenomenon.

OBJECTIVES

The foremost purpose of this study was to compare the distribution of IL28B genotypes between Iranian healthy individuals and patients with chronic hepatitis C.

PATIENTS AND METHODS

In this study, 921 patients with chronic hepatitis C and 142 healthy individuals were included. The IL28B rs12979860 and rs8099917 polymorphisms were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The frequency of IL28B rs12979860 CC, CT, and TT genotypes in chronic hepatitis C patients was 38%, 48.8%, and 13.2% and in healthy individuals was 43.7%, 48.6%, and 7.7%. Also, the frequency of IL28B rs8099917 TT, GT, and GG genotypes in chronic hepatitis C patients was 58.3%, 37.1%, and 4.6% and in healthy individuals was 64.1%, 32.4% and 3.5%. The differences in the distribution of IL28B rs12979860 and rs8099917 genotypes between patients with chronic hepatitis C and healthy individuals were not statistically significant. When we compared the distribution of IL28B genotypes between the healthy group and the HCV infected patients by HCV genotype, we found 9.8% higher frequency of rs12979860 CC genotype in the healthy individuals than HCV genotype 1 infected patients (P = 0.03) however there was no significant difference in the distribution of rs12979860 genotypes between the healthy and HCV genotype 3 infected groups (P = 0.46).

CONCLUSIONS

It seems that the impact of IL28B polymorphism on the spontaneous clearance of HCV genotype 1 is more prominent than HCV genotype 3 which results in the observation of higher rs12979860 C allele frequency in chronic hepatitis C patients with HCV genotype 3 than HCV genotype 1.

Abundant drug-resistant NS3 mutants detected by deep sequencing in hepatitis C virus-infected patients undergoing NS3 protease inhibitor monotherapy

The high genetic variation of hepatitis C virus (HCV) results in rapid selection of drug resistance mutations (DRMs) during monotherapy with direct-acting antivirals (DAAs). It has been proposed that each possible single mutant preexists in infected individuals; however, the levels of preexisting DRMs are too low to be directly quantified in most patients using current techniques. In this study, we evaluated the presence of DRMs in HCV-infected patients treated with the HCV protease inhibitors GS-9256 or GS-9451 as monotherapy using deep sequencing in 137 longitudinal samples from 45 patients. Software was developed to analyze deep-sequencing results with an assay cutoff of 0.25%. No NS3 DRMs that confer resistance to GS-9256 and GS-9451 (R155K, A156T, and D168V/E) were observed in 33 baseline samples at >0.25%. In contrast, these and other substitutions at NS3 positions 155, 156, and 168 were detected in 19/27 patients at day 2 (24 h) and 21/21 at day 4 (84 h) of monotherapy but not in placebo-treated patients. Based on the DRM growth kinetics during drug treatment, pretreated NS3 mutations at amino acids 155, 156, and 168 were estimated on average at 0.025% and 0.015% per genotype 1a and 1b HCV-infected patients, respectively. Relative fitness of the DRM viruses was shown to be significantly lower than the wild type. Deep-sequencing analyses of NS3 protease inhibitor-treated HCV-infected patients suggest a limit of HCV viral load suppression of 3.6 to 3.8 log(10) with NS3 protease inhibitor monotherapy that does not suppress the identified preexisting NS3 DRMs and thus a need for a combination therapy.

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

In patients with chronic hepatitis C virus (HCV) infection, several variants of the interleukin-28B (IL28B) gene have been shown to correlate significantly with a sustained virologic response (SVR). Recent evidence shows that determination of one single IL28B polymorphism, rs12979860, is sufficient for predicting treatment outcome. We examined whether the combined determination of the IL28B single-nucleotide polymorphisms (SNPs), rs12979860, rs8099917, rs12980275, and rs8103142, might improve the prediction of SVR in patients with HCV. In the study cohort, 54% of 942 patients with chronic HCV type 1 infection had SVR. The IL28B SNPs, rs12979860CC and rs8099917TT, correlated significantly with SVR (68% and 62%). The SNPs, rs12980275 and rs8103142, were in strong linkage disequilibrium with rs12979860 and were not included in further analysis. In homozygous carriers of the rs12979860 responder allele C, additional genotyping of the rs8099917 SNP had no effect on response prediction, whereas in carriers of the rs12979860 nonresponder allele, the rs8099917 SNP improved the response prediction. In heterozygous carriers of the rs12979860 nonresponder T allele, SVR rates were 55% in the presence of the rs8099917TT genotype and 40% in patients carrying the rs8099917 TG or GG genotype. Analysis of an independent confirmation cohort of 377 HCV type 1-infected patients verified the significant difference in SVR rates between the combined genotypes, rs12979860CT/rs8099917TT and rs12979860CT/rs8099917TG (38% versus 21%; P = 0.018).

CONCLUSION

Treatment outcome prediction could not be improved in homozygous carriers of the IL28B rs12979860 C responder allele by the additional determination of the rs8099917 SNP. There is evidence that a significant proportion of heterozygous carriers of the rs12979860 T nonresponder allele can profit with respect to SVR prediction by further determination of the rs8099917 SNP. (HEPATOLOGY 2012;55:1700-1710).

Evaluation of interleukin 28B single nucleotide polymorphisms in infants suffering from bronchiolitis

The genetic diversity of the host is believed to be the key of the diversity in the clinical presentation of bronchiolitis. The aim of this study was to determine whether the known rs12979860 and rs8099917 single nucleotide polymorphisms (SNPs) in interleukin (IL)28B region, influence clinical features and natural history of bronchiolitis. Both SNPs showed no significant association with the risk of hospitalization for respiratory syncytial virus (RSV), viral load, disease severity, and other clinical features of patients. Interestingly infants carrying IL28B rs12979860 TT genotype had lower age at hospital admission than that of infants carrying CC/CT genotypes. Overall our results indicate that both IL28B SNPs had no impact on the clinical course of bronchiolitis with the only exception of the IL28B rs12979860 SNP which increased the risk of hospitalization for bronchiolitis at early age.

Interleukin 28B genetic polymorphisms and viral factors help identify HCV genotype-1 patients who benefit from 24-week pegylated interferon plus ribavirin therapy

BACKGROUND

Interleukin 28B (IL28B) single nucleotide polymorphism (SNP) genotypes and viral factors can predict sustained virological response (SVR) in HCV genotype-1 (HCV-1) patients receiving 48 weeks of pegylated interferon and ribavirin. Whether these factors would identify those patients who can benefit from a shorter duration of therapy remains unclear.

METHODS

Treatment-naive HCV-1 patients (n=662) receiving 24 or 48 weeks of combination therapy were enrolled. Baseline demographic data, HCV viral load, IL28B SNP genotypes (rs8099917), duration of therapy and rapid virological response (RVR) were evaluated to predict SVR. The SVR rates were further stratified by the independent factors and compared.

RESULTS

The IL28B rs8099917 TT genotype, low baseline viral load (HCV RNA≤600,000 IU/ml), RVR and 48-week therapy independently predicted SVR. In RVR patients with the IL28B rs8099917 TT genotype, the SVR rate of 24-week therapy was comparable to 48-week therapy (95% versus 99%; P=0.21) at low baseline viral load, but was inferior to 48-week therapy (70% versus 97%; P<0.001) at high baseline viral load. In non-RVR patients, the SVR rate of 24-week therapy was inferior to 48-week therapy for those with the IL28B rs8099917 TT genotype but high baseline viral load (23% versus 62%; P<0.001), and those with the IL28B rs8099917 GT/GG genotype but low baseline viral load (0% versus 33%; P=0.02).

CONCLUSIONS

HCV-1 patients simultaneously bearing the IL28B rs8099917 TT genotype, low baseline viral load and RVR can benefit from a shorter duration of combination therapy.

The Correlation of Il28B Genotype With Sustained Virologic Response In Romanian patients With Chronic Hepatitis C

BACKGROUND

Multiple variables influencing the sustained virologic response (SVR) in chronic hepatitis C have been evaluated. One of them is genetic polymorphism near the IL28B gene.

OBJECTIVES

The aim of this study was to evaluate the influence of IL28B genotypes on SVR rates in a group of patients with chronic hepatitis C from the western part of Romania.

PATIENTS AND METHODS

A retrospective study was performed in 107 consecutive patients, previously treated with standard-of-care medication for chronic hepatitis C, identified from the databases of 2 centers. Patient demographics, viral load before treatment and at 12, 24, and 72 weeks from the treatment start, and IL28B genotype were evaluated.

RESULTS

Among the 107 patents in the study group, 54 patients had SVR (50.5%), and 62 (57.9%) showed a complete early virologic response (cEVR). The SVR rates according to IL28B genotype were as follows: 73.1% in patients with genotype C/C, 40.9% in those with genotype C/T, and 57.1% in those with genotype T/T (i.e., 73.1% among patients with the C/C genotype vs. 43.7% among those with non-C/C genotypes; P = 0.0126). The cEVR rates were 80.8% in patients with the C/C genotype vs. 51.2% in those with non-C/C genotypes (P = 0.011).

CONCLUSIONS

In our cohort of 107 Caucasian HCV patients, the SVR rate was 50.5% with standard-of-care treatment. The SVR rate was directly related to the IL28B genotype: 73.1% in the C/C genotype vs. 43.7% in non-C/C genotypes (P = 0.0126).

Direct-acting antiviral (DAA) actions in treatment-naïve patients

The introduction of telaprevir (TVR) and boceprevir (BOC), the first approved protease inhibitors against hepatitis C virus (HCV), into clinical practice represented the start of an exciting new era of HCV treatment. In addition to improving sustained virological response (SVR) rates in HCV genotype-1 treatment-naïve patients, these drugs administered as a triple combination with pegylated interferon (pegIFN) and ribavirin (RBV) provide opportunities for more patients to receive shorter durations of treatment (24-28 weeks) than with pegIFN/RBV alone (48 weeks). Also, the use of TVR and BOC is being enhanced by the acquisition of further data on predictors of SVR, thereby increasing patients'chances of being cured of their HCV infection.

IL28B polymorphism and genetic biomarkers of viral clearance in hepatitis C virus infection

Infection with hepatitis C virus (HCV) is a major global health issue. Only a small proportion of patients clear the virus spontaneously and the majority develop chronic hepatitis C infection. Chronic hepatitis C is one of the most common causes of advanced liver disease in the western world and is now the leading indication for liver transplantation. Unfortunately, the standard treatment, consisting of pegylated-interferon and ribavirin, is suboptimal. Less than 50% of patients infected with HCV genotype 1 are cured, treatment is costly and is associated with significant toxicity. Therefore, there has been a need to identify accurate predictors of treatment outcome to facilitate treatment decision-making. Four independent genome-wide association studies have recently confirmed an association between genetic variation in the region of the IL28B gene and treatment outcome in HCV-1 patients. Patients who carry the good response variant are two- to three-fold more likely to be cured. The difference in the frequency of the good response variant between patients of different ethnic background explains much of the recognized ethnic disparity in treatment response rates. The IL28B variants are also associated with likelihood of spontaneous clearance of HCV infection. This discovery represents a significant advance in our ability to personalize HCV therapy, as well as suggesting novel avenues for research into viral pathogenesis and therapeutic development.