Analysis of IL28B variants in an Egyptian population defines the 20 kilobases minimal region involved in spontaneous clearance of hepatitis C virus

Spontaneous clearance of hepatitis C virus (HCV) occurs in ~30% of acute infections. Host genetics play a major role in HCV clearance, with a strong effect of single nucleotide polymorphisms (SNPs) of the IL28B gene already found in different populations, mostly infected with viral genotypes 1 and 3. Egypt has the highest prevalence of HCV infection in the world, which is mostly due to viral genotype 4. We investigated the role of several IL28B SNPs in HCV spontaneous clearance in an Egyptian population. We selected nine SNPs within the IL28B genomic region covering the linkage disequilibrium (LD) block known to be associated with HCV clearance in European populations. These SNPs were genotyped in 261 HCV-infected Egyptian subjects (130 with spontaneous clearance and 131 with chronic infection). The most associated SNPs were rs12979860 (P = 1.6 × 10(-7)) and the non-synonymous IL28B SNP, rs8103142 (P = 1.6 × 10(-7)). Interestingly, three SNPs at the two bounds of the region were monomorphic, reducing the size of the LD block in which the causal variants are potentially located to ～20 kilobases. HCV clearance in Egypt was associated with a region of IL28B smaller than that identified in European populations, and involved the non-synonymous IL28B SNP, rs8103142.     

None of the Six SNPs of IL28B Could Predict Treatment Responses in Genotype 2 Chronic HCV Infected Patients by Propensity Score Matching Analysis

Background & Aims

A combination of pegylated interferon-alpha and ribavirin (PR) is the standard therapy for patients with chronic hepatitis C. The impact of polymorphism of interleukin-28B (IL28B) on sustained virological response (SVR) to PR has been well documented in patients with CHC genotype-1 (GT1), but it is controversial in genotype-2 (GT2) CHC patients. This study investigated the predictability of six single nucleotide polymorphisms (SNP) of IL28B on the treatment responses of PR in patients with CHC GT2.

Method

197 CHC GT2 consecutive patients who received PR treatment in our prospective cohort were enrolled. Hepatitis C virus (HCV) genotyping, quantification of HCV-RNA and genotyping of the ten SNPs of IL28B were performed. Six SNPs of IL28B were chosen for analysis. The propensity score matching (PSM) analysis was applied using patients with CHC GT1 in another prospective cohort as a positive comparison to avoid covariate bias.

Results

The distribution of the six SNPs was similar in GT1 and GT2 patients. Five of these SNPs had strong association with treatment responses in GT1 but not in GT2 patients. After PSM analysis, these five SNPs still showed strong association with rapid virological response (RVR), cEVR and SVR in GT1 and had no influence in GT2 patients. Furthermore, rs12979860 and baseline viral load were the predictors for both RVR and SVR in GT1 patients. However, only baseline viral load could predict RVR and SVR in GT2 patients. In addition, in patients without RVR, rs12979860 was the only predictor for SVR in GT1 but no predictor for SVR was found in GT2.

Conclusions

The genetic polymorphisms of IL28B had no impact on treatment responses in GT2 patients.     

Chronic hepatitis B and IL28B rs12979860 polymorphism: preliminary study

The aim of this study is to evaluate the role of IL28B rs12979860 polymorphism on pegylated interferon (peg IFN) and oral antiviral treatment in chronic hepatitis B (CHB) patients and to investigate the relationship between the severities of illness with this polymorphism. 74 CHB patients who are received treatment, 61 asymptomatic carriers and 40 healthy controls were recruited in this study. Genomic DNA of controls and patients were extracted from whole blood using High Pure PCR Template Preparation Kit (Roche, Mannheim, Germany) according to the manufacturer’s instructions and stored at 4 °C. Genotype distribution of the IL-28B polymorphism at position ?3176C/T (rs12979860) (LightMix Kit IL28B, Cat.-No. 40-0588-32 TIB MOLBIOL, Berlin, Germany) was detected by real time PCR (Roche Diagnostics, Manheim, Germany). Thirty of the patients with CHB received peg IFN-α treatment. There were no significant difference between groups by means of age, gender and IL28B rs12979860 polymorphism (p = 0.122, p = 0.07, p = 0.376 respectively). Patients with chronic hepatitis were categorized as grade and stage (minimal, moderate and severe) and then were analyzed for the polymorphism. There was no effect of IL28B ?3176 C/T polymorphism on severity of illness (p = 0.293 for grade, p = 0.911 for stage). When the CHB treatment monitored in different time arrivals (beginning, 3th, 6th and 12th months of the treatment) in order to see if there was an effect on virological and biological response none of the genotypes of IL28B ?3176C/T polymorphism altered peg IFN or oral antiviral treatment process. There are conflicting results about the role of IL28B rs12979860 polymorphism in CHB in the literature. In this preliminary study, we observed that IL28B rs12979860 polymorphism was not related with severity of illness and also was not effective on treatment response.     

IL28B SNP rs12979860 is a critical predictor for on-treatment and sustained virologic response in patients with hepatitis C virus genotype-1 infection

Background

Single nucleotide polymorphisms (SNPs) of interleukin-28B (IL28B) have received considerable interest for their association with sustained virological response (SVR) when treating patients of genotype-1 hepatitis C virus (GT1-HCV) chronic infection with pegylated interferon and ribavirin (PegIFN/RBV). This study was to investigate the predictive power of IL28B SNPs for on-treatment responses and SVR in treatment-naïve patients with GT1-HCV chronic infection.

Methodology/Principal Findings

We analyzed ten SNPs of IL28B in 191 treatment-naïve patients with GT1-HCV chronic infection who received PegIFN/RBV. In these patients, rapid virological response (RVR), early virological response (EVR) and SVR were achieved in 69.6%, 95.8% and 68.6% of the patients, respectively. Multivariate analysis (odds ratio; 95% confidence interval; P value) indicated age (0.96; 0.93–0.99; 0.012), low baseline viral load (4.65; 2.23–9.66; <0.001) and CC genotype of rs12979860 (7.74; 2.55–23.53; <0.001) but no other SNPs were independent predictors for SVR. In addition, none of the ten SNPs examined were associated with baseline viral load and stages of liver fibrosis. Regarding RVR, low baseline viral load (2.83; 1.40–5.73; 0.004) and CC genotype of rs12979860 (10.52; 3.45–32.04; <0.001) were two critical predictors. As for EVR, only CC genotype of rs12979860 (36.21; 6.68–196.38; <0.001) was the predictor. Similarly, for end of treatment response (ETR), CC genotype of rs12979860 (15.42; 4.62–51.18; <0.001) was the only predictor. For patients with RVR, only low baseline viral load (3.90; 1.57–9.68; 0.003) could predict the SVR. For patients without RVR, only rs12979860 (4.60; 1.13–18.65; 0.033) was the predictor for SVR.

Conclusions/Significance

rs12979860 is the critical predictor for RVR, EVR, ETR and SVR in treatment-naïve patients of GT1-HCV chronic infection. Furthermore, this SNP is the only predictor for SVR in patients without RVR. These results have provided evidence that rs12979860 is the ideal IL28B SNP for genetic testing in treating patients of GT1-HCV chronic infection.     

Single nucleotide polymorphism rs1800872 in the promoter region of the IL10 gene is associated with predisposition to chronic hepatitis C in Russian population

Previously, we studied an association of two IL28B gene single nucleotide polymorphisms (SNPs) and three IL10 gene SNPs with predisposition to tick-borne encephalitis in a Russian population. In this study, a possible involvement of these SNPs in the development of predisposition to chronic hepatitis C (caused by structurally similar, related virus from the Flaviviridae family) was investigated in the same population. Only the IL10 promoter rs1800872 SNP was associated with predisposition to chronic hepatitis C. This SNP seems to be a common genetic marker of predisposition to two diseases caused by hepatitis C and tick-borne encephalitis viruses in Russian population.     

Impact of IL28B,APOH and ITPA Polymorphisms on Efficacy and Safety of TVR- or BOC-Based Triple Therapy in Treatment-Experienced HCV-1 Patients with Compensated Cirrhosis from the ANRS CO20-CUPIC Study

Background

Human genetic factors influence the outcome of pegylated interferon and ribavirin hepatitis C therapy. We explored the role of IL28B, APOH and ITPA SNPs on the outcomes of triple therapy including telaprevir or boceprevir in patients with compensated cirrhosis chronically infected with HCV-1.

Patients and Methods

A total of 256 HCV-1 Caucasian treatment-experienced patients with compensated cirrhosis from the ANRS CO20-CUPIC cohort were genotyped for a total of 10 candidate SNPs in IL28B (rs12979860 and rs368234815), APOH (rs8178822, rs12944940, rs10048158, rs52797880, rs1801689 and rs1801690) and ITPA (rs1127354 and rs7270101). We tested the association of IL28B and APOH SNPs with sustained virological response and of ITPA SNPs with anemia related phenotypes by means of logistic regression assuming an additive genetic model.

Results

None of the six APOH SNPs were associated with sustained virological response. The favorable alleles of the IL28B SNPs rs12979860 and rs368234815 were associated with sustained virological response (rs12979860: OR = 2.35[1.50–3.70], P = 2x10^-4). Refined analysis showed that the effect of IL28B SNPs on sustained virological response was restricted to prior PegIFN/RBV relapse (OR = 3.80[1.82–8.92], P = 8x10^-4). We also confirmed the association between ITPA low activity alleles and protection against early hemoglobin decline in triple therapy (P = 2x10^-5).

Conclusion

Our results suggest that the screening of rs12979860 may remain interesting for decision making in prior relapse HCV-1 Caucasian patients with compensated cirrhosis eligible for a telaprevir- or boceprevir-based therapy.     

Genetic variation in IL28B is associated with the development of hepatitis B-related hepatocellular carcinoma

To evaluate the role of host IL28B (interleukin 28B; interferon lambda 3) single nucleotide polymorphisms (SNPs) in predicting hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) susceptibility, three SNPs in the IL28B gene (rs12979860C/T, rs8099917G/T and rs12980275G/A) were examined in 330 subjects (including 154 HBV-related HCC patients, 86 non-HCC patients with chronic hepatitis B (CHB), 43 HBV self-limited infections and 47 healthy controls). Notably, the frequency of CC homozygosity was 91.5% in healthy controls and 72.9% in CHB, the difference being statistically significant (χ(2) = 6.40, P = 0.01). The statistically difference was seen between healthy controls (91.5%) and HCC (74.7%) (χ(2) = 6.05, P = 0.01). However, this significant finding was not seen between HBV self-limited and healthy controls. Carriers of the minor T allele in rs12979860 had a higher risk of HCC compared with non-carriers (χ(2) = 4.44, P = 0.04). Haplotype analyses revealed significant association between haplotype C-T-A and healthy controls, but not with the HCC group (96.6 vs. 82.0%, χ(2) = 6.08, P = 0.01). Analyses of genotype combination and gene-gene interaction showed that there was a positive interaction between rs12979860 and rs12980275, with an OR rate of 11.79 (likelihood test, P = 0.04). Our results suggest that the IL28B rs12979860 C/T polymorphism might affect susceptibility to the chronic HBV infection and progression of HCC. Of note, the T allele and non-CC genotypes have strong predictive effect of increasing susceptibility of chronic HBV infection and HCC.     

Development of new IL28B genotyping method using Invader Plus assay

IL28B polymorphism is associated with the response to pegylated interferon-α with ribavirin (PEG-IFN-α/RBV) treatment in chronic hepatitis C patients. As a genotyping assay for IL28B single nucleotide polymorphisms (SNPs) in clinical practice, the Invader Plus assay was developed. The accuracy, intra-assay, inter-assay precision, and the limit of detection of the Invader Plus assay were evaluated. Two SNPs (rs8099917 and rs12979860) associated with IL28B were genotyped by the Invader Plus and TaqMan assay in 512 Japanese patients. In comparison with direct sequencing, the Invader Plus assay showed 99% accuracy in rs8099917 and 100% accuracy in rs12979860. Intra-assay and inter-assay precision were sufficient to use in clinical practice and the detection limit was 1ngDNA/assay. Genotyping by rs8099917 showed that 361 (71%), 144 (28%) and seven (1%) of the patients were major homozygous, heterozygous and minor homozygous types, respectively. Five of the 512 cases (1%) had haplotype differences, but none showed differences between the two genotyping methods. For patients with HCV genotype 1, the prevalence of responders in the major homozygous type was 83.3%, and that of non-responders in the minor heterozygous/homozygous type was 72.5%. A convenient IL28B genotyping method using the Invader Plus assay could be useful to predict the treatment outcome in clinical practice.     

Deciphering the interleukin 28B variants that better predict response to pegylated interferon-α and ribavirin therapy in HCV/HIV-1 coinfected patients

Previous works have documented the contribution of different IL28B-associated SNPs to spontaneous HCV clearance. This study investigated the effect of different interleukin (IL) 28B genetic variants on interferon (IFN)-based therapy response. We genotyped eight IL28B single-nucleotide polymorphisms (SNPs) in a cohort of 197 hepatitis C virus (HCV)/human immunodeficiency virus type 1 (HIV-1) coinfected patients from our clinic unit who received combined pegylated (peg)-IFN-α and ribavirin (RBV) therapy. This analysis included the two strongest tag predictors for HCV clearance, rs8099917 and rs12979860, and four causal variants (rs4803219, rs28416813, rs8103142, and rs4803217) located in the IL28B promoter, coding, and 3′-untranslated regions. Haplotypes carrying the major alleles at IL28B SNPs were highly associated with sustained virological responses (SVRs) after treatment with peg-IFN-α and RBV [odds ratio (OR) = 2.5, 95% confidence interval (CI) = 1.6–4.0, 4.0×10⁻⁵]. Three causal SNP genotypes (rs28416813, rs8103142, and rs4803217) displayed the highest association with SVRs (OR = 3.7, 95% CI = 2.0–6.7, p = 1.3×10⁻⁵). All four causal variants were in high linkage disequilibrium, both among themselves (r²≥0.94) and with the rs12979860 variant (r²≥0.92). In contrast, rs8099917 was in low linkage disequilibrium with the four causal variants (r²≤0.45) and with the rs12979860 variant (r² = 0.45). These results demonstrate that rs12979860, compared to rs8099917, may be a better predictor of response to the peg-IFN/RBV treatment among HCV/HIV-1 coinfected patients. Moreover, causal IL28B variants are strongly associated with treatment SVRs.     

A tetra-primer amplification refractory mutation system-polymerase chain reaction for the detection of rs8099917 IL28B genotype

Two single nucleotide polymorphisms (SNP, rs8099917, rs12979860) near the IL28B gene have been illustrated as outcome predictors of hepatitis C virus (HCV) treatment with pegylated interferon/ribavirin. The aim of the present study was to design a simple tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) for the evaluation of the rs8099917 IL28B gene polymorphism. We efficiently designed a T-ARMS-PCR for detection of rs8099917 IL28B. Using this method, we genotyped 83 subjects with NAFLD (nonalcoholic fatty liver disease) and 93 healthy subjects. No significant differences were found in allelic and genotypic frequencies of rs8099917 IL28B gene polymorphism between NAFLD subjects and controls. The frequency of minor allele (G allele) was 0.13 in healthy and 0.19 in NAFLD subjects. In conclusion, we designed a simple, inexpensive, and reproducible T-ARMS-PCR for detection of rs8099917 IL28B polymorphism which can be used for routine assay. In addition, we found that rs8099917 polymorphism is not a risk factor for predisposition to NAFLD in a sample of Iranian population. Larger studies with different ethnics are required to validate our findings.     

Response to treatment in Brazilian patients with chronic hepatitis C is associated with a single-nucleotide polymorphism near the interleukin-28B gene

A single-nucleotide polymorphism (SNP) upstream of interleukin (IL)28B was recently identified as an important predictor of the outcome of chronic hepatitis C patients treated with pegylated interferon plus ribavirin (PEG-IFN/RBV). The aim of this study was to investigate the association between the IL28B gene polymorphism (rs12979860) and virological response in chronic hepatitis C patients. Brazilian patients (n = 263) who were infected with hepatitis C virus (HCV) genotype 1 and were receiving PEG-IFN/RBV were genotyped. Early virological response (EVR) (12 weeks), end-of-treatment response (EOTR) (48 weeks), sustained virological response (SVR) (72 weeks) and relapse were evaluated using conventional and quantitative polymerase chain reaction (PCR) assays. The frequency of the C allele in the population was 39%. Overall, 43% of patients experienced SVR. The IL28B CC genotype was significantly associated with higher treatment response rates and a lower relapse rate compared to the other genotypes [84% vs. 58% EVR, 92% vs. 63% EOTR, 76% vs. 38% SVR and 17% vs. 40% relapse rate in CC vs. other genotypes (CT and TT), respectively]. Thus, the IL28B genotype appears to be a strong predictor of SVR following PEG-IFN/RBV therapy in treatment-naïve Brazilian patients infected with HCV genotype 1. This study, together with similar research examining other SNPs, should help to define adequate protocols for the treatment of patients infected with HCV genotype 1, especially those with a poor prognosis.     

Association between IL10, IL10RA, and IL10RB SNPs and ischemic stroke with hypertension in Korean population

The pathogenesis of stroke is associated with the immune and inflammatory responses. Cytokines, such as interleukin 10 (IL10), play an important role in the process of inflammation. To investigate whether IL10, IL10RA, and IL10RB polymorphisms are associated with the risk of ischemic stroke (IS), selected two IL10 SNPs (rs1518111 and rs1554286), three IL10RA SNPs (rs2256111, rs4252243, and rs2228054), and two IL10RB SNPs (rs999788 and rs2834167) were analyzed in 120 patients with IS and 285 control subjects. All IS patients were classified into the clinical subgroups, according to the levels of blood pressure (hypertension, present and absent), fasting plasma glucose (diabetes mellitus, present and absent), and lipids (dyslipidemia, present and absent). SNPStats and SPSS 18.0 program were used to obtain the odds ratios, 95 % confidence intervals, and P values. Multiple logistic regression models (codominant1, codominant2, dominant, recessive, and log-additive models) were performed to analyze the genetic data. Seven polymorphisms were not associated with the IS, but showed significant associations with hypertension, in the risk of IS. These results suggest that the IL10, IL10RA, and IL10RB genes may be contributed to the hypertension in the risk of IS in the Korean population.     

Predictive Value of Interferon-Lambda Gene Polymorphisms for Treatment Response in Chronic Hepatitis C

Background

IL28B gene polymorphism is the best baseline predictor of response to interferon alfa-based antiviral therapies in chronic hepatitis C. Recently, a new IFN-L4 polymorphism was identified as first potential functional variant for induction of IL28B expression. Individualization of interferon alfa-based therapies based on a combination of IL28B/IFN-L4 polymorphisms may help to optimize virologic outcome and economic resources.

Methods

Optimization of treatment outcome prediction was assessed by combination of different IL28B and IFN-L4 polymorphisms in patients with chronic HCV genotype 1 (n = 385), 2/3 (n = 267), and 4 (n = 220) infection treated with pegylated interferon alfa (PEG-IFN) and ribavirin with (n = 79) or without telaprevir. Healthy people from Germany (n = 283) and Egypt (n = 96) served as controls.

Results

Frequencies of beneficial IL28B rs12979860 C/C genotypes were lower in HCV genotype 1/4 infected patients in comparison to controls (20–35% vs. 46–47%) this was also true for ss469415590 TT/TT (20–35% vs. 45–47%). Single interferon-lambda SNPs (rs12979860, rs8099917, ss469415590) correlated with sustained virologic response (SVR) in genotype 1, 3, and 4 infected patients while no association was observed for genotype 2. Interestingly, in genotype 3 infected patients, best SVR prediction was based on IFN-L4 genotype. Prediction of SVR with high accuracy (71–96%) was possible in genotype 1, 2, 3 and 4 infected patients who received PEG-IFN/ribavirin combination therapy by selection of beneficial IL28B rs12979860 C/C and/or ss469415590 TT/TT genotypes (p<0.001). For triple therapy with first generation protease inhibitors (PIs) (boceprevir, telaprevir) prediction of high SVR (90%) rates was based on the presence of at least one beneficial genotype of the 3 IFN-lambda SNPs.

Conclusion

IFN-L4 seems to be the best single predictor of SVR in genotype 3 infected patients. For optimized prediction of SVR by treatment with dual combination or first generation PI triple therapies, grouping of interferon-lambda haplotypes may be helpful with positive predictive values of 71–96%.     

Pathway analysis of genome-wide association study on serum prostate-specific antigen levels

The wide application of prostate-specific antigen (PSA) has contributed to the early diagnosis and improved management of prostate cancer (PCa). Accumulating evidence has suggested the involvement of genetic components in regulating serum PSA levels, and several single nucleotide polymorphisms (SNPs) have been identified by genome-wide association studies (GWASs). However, the GWASs' results have the limited power to identify the causal variants and pathways. After the quality control filters, a total of 330,540 genotyped SNPs from one GWAS with 657 PCa-free Caucasian males were included for the identify candidate causal SNPs and pathways (ICSNPathway) analysis. In addition, the genotype–phenotype association analysis has been conducted with the data from HapMap database. Overall, a total of four SNPs in three genes and six pathways were identified by ICSNPathway analysis, which in total provided three hypothetical mechanisms. First, CYP26B1 rs2241057 polymorphism (nonsynonymous coding) which leads to a Leu-to-Ser amino acid shift at position 264, was implicated in the pathways including meiosis, proximal/distal pattern formation, and M phase of meiotic cell cycle. Second, CLIC5 rs3734207 and rs11752816 polymorphisms (regulatory region) to the 2 iron, 2 sulfur cluster binding pathway through regulating expression levels of CLIC5 mRNA. Third, rs4819522 polymorphism (nonsynonymous coding) leads to a Thr-to-Met transition at position 350 of TBX1 and involves in the pathways about gland and endocrine system development. In summary, our results demonstrated four candidate SNPs in three genes (CYP26B1 rs2241057, CISD1 rs2251039, rs2590370, and TBX1 rs4819522 polymorphisms), which were involved in six potential pathways to influence serum PSA levels.     

An association study between IL1RAPL2 gene and non-specific mental retardation in Chinese children

Non-specific mental retardation (NSMR) is one of common children psychiatric diseases with a high prevalence (1–3%). Here we investigated the association between the genetic variants of IL1RAPL2 gene and NSMR in the children of QinBa region of China. We chose five common SNPs of IL1RAPL2, examined their individual genotype frequencies using the conventional polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method, and evaluated the association between these genetic polymorphisms and NSMR with the suitable biostatistic software. The allele and genotype distributions of two SNPs (rs5962298 and rs9887672) showed significant differences between the control and NSMR groups (allele: p = 0.020 and 0.017; genotype: p = 0.025 for rs9887672 respectively). The distribution differences became more significant in girls, but disappeared in boys, suggesting a gender effect. Taken together, we provide substantial evidence that IL1RAPL2 conferred a NSMR susceptibility to children of Qinba region in China. In future, further work should be carried out to scan mutations and to investigate the specific-gender effect in this gene.     

Host Genetics Predict Clinical Deterioration in HCV-Related Cirrhosis

Single nucleotide polymorphisms (SNPs) in the epidermal growth factor (EGF, rs4444903), patatin-like phospholipase domain-containing protein 3 (PNPLA3, rs738409) genes, and near the interleukin-28B (IL28B, rs12979860) gene are linked to treatment response, fibrosis, and hepatocellular carcinoma (HCC) in chronic hepatitis C. Whether these SNPs independently or in combination predict clinical deterioration in hepatitis C virus (HCV)-related cirrhosis is unknown. We genotyped SNPs in EGF, PNPLA3, and IL28B from liver tissue from 169 patients with biopsy-proven HCV cirrhosis. We estimated risk of clinical deterioration, defined as development of ascites, encephalopathy, variceal hemorrhage, HCC, or liver-related death using Cox proportional hazards modeling. During a median follow-up of 6.6 years, 66 of 169 patients experienced clinical deterioration. EGF non-AA, PNPLA3 non-CC, and IL28B non-CC genotypes were each associated with increased risk of clinical deterioration in age, sex, and race-adjusted analysis. Only EGF non-AA genotype was independently associated with increased risk of clinical deterioration (hazard ratio [HR] 2.87; 95% confidence interval [CI] 1.31–6.25) after additionally adjusting for bilirubin, albumin, and platelets. Compared to subjects who had 0–1 unfavorable genotypes, the HR for clinical deterioration was 1.79 (95%CI 0.96–3.35) for 2 unfavorable genotypes and 4.03 (95%CI 2.13–7.62) for unfavorable genotypes for all three loci (P_trend<0.0001). In conclusion, among HCV cirrhotics, EGF non-AA genotype is independently associated with increased risk for clinical deterioration. Specific PNPLA3 and IL28B genotypes also appear to be associated with clinical deterioration. These SNPs have potential to identify patients with HCV-related cirrhosis who require more intensive monitoring for decompensation or future therapies preventing disease progression.     

Association Analysis between SNPs in IL-28B Gene and the Progress of Hepatitis B Infection in Han Chinese

Objective

As a candidate gene association study, we investigated the genetic association of SNPs in IL-28B genes with different outcomes of HBV infection, including LC and HCC occurrence.

Methods

Chinese Han subjects were categorized into two groups: 406 LC caused by CHB and 406 HCC caused by CHB. Genomic DNA was isolated from whole blood samples, SNPs were detected using high resolution melting curve (HRM) method. PCR amplification was carried out under the same conditions in a 96-well plate in Real-Time PCR System. Then 341 LC and 356 HCC patients caused by HBV infection were analyzed as a verification by independent sample. 393 CHB patients and 244 health subjects were included as control.

Results

CHB patients who progress to LC or HCC showed a significant different frequency in rs12979860 (p = 0.046). Patients with HCC carried more frequently the T alleles in rs12979860 comparison to LC. Same results were found in the independent sample.

Conclusion

IL-28B rs12979860 C/T polymorphism T allele appears to be more prevalent in patients with HCC than in LC. Carriage of this allele seems to enhance the risk for developing HCC. Gene polymorphism of IL-28B may confer symptomatic specificity in progress and extent of hepatitis B infection.     

IL28B Polymorphism Correlates with Active Hepatitis in Patients with HBeAg-Negative Chronic Hepatitis B

Background & Aims

The clinical relevance of single nucleotide polymorphisms (SNPs) near the IL28B gene is controversial in patients with hepatitis B virus (HBV) infection. This study aimed to investigate the role of viral and host factors, including IL28B genotypes, in the natural course of chronic hepatitis B (CHB).

Methods

The study enrolled consecutive 115 treatment-naive CHB patients. HBV viral loads, genotypes, precore and basal core promotor mutations, serum hepatitis B surface antigen (HBsAg) and interferon-gamma inducible protein 10 (IP-10) levels as well as four SNPs of IL28B were determined. Serial alanine transaminase (ALT) levels in the previous one year before enrollment at an interval of three months were recorded. Factors associated with active hepatitis, defined as persistent ALT >2× upper limit of normal (ULN) or a peak ALT level >5× ULN, were evaluated.

Results

The prevalence of rs8105790 TT, rs12979860 CC, rs8099917 TT, and rs10853728 CC genotypes were 88.3%, 87.4%, 88.4% and 70.9%, respectively. In HBeAg-positive patients (n = 48), HBV viral load correlated with active hepatitis, while in HBeAg-negative patients (n = 67), rs10853728 CC genotype (p = 0.032) and a trend of higher IP-10 levels (p = 0.092) were associated with active hepatitis. In multivariate analysis, high viral load (HBV DNA >10⁸ IU/mL, p = 0.042, odds ratio = 3.946) was significantly associated with HBeAg-positive hepatitis, whereas rs10853728 CC genotype (p = 0.019, odds ratio = 3.927) was the only independent factor associated with active hepatitis in HBeAg-negative population.

Conclusions

HBV viral load and IL28B rs10853728 CC genotype correlated with hepatitis activity in HBeAg-positive and HBeAg-negative CHB, respectively. Both viral and host factors play roles in disease activity during different phases of CHB.     

Association between IL28B Polymorphisms and Spontaneous Clearance of Hepatitis B Virus Infection

Background/Aims

Single-nucleotide polymorphisms (SNPs) near the interleukin 28B gene (IL28B; interferon [IFN]-λ-3) are associated with outcomes of chronic hepatitis C virus (HCV) and hepatitis B virus (HBV) infection treated with peginterferon (PEG-IFN) alpha-based antiviral therapy. In this study, we investigated the influence of IL28B polymorphisms on spontaneous clearance of HBV infection in a large Korean cohort.

Methods

Between January 2007 and June 2010, a total of 208 patients with chronic HBV infection and newly diagnosed HBV-related hepatocellular carcinoma were recruited as the CC group [HBsAg(+) for >6 months, anti-HBc(+), and anti-HBs(-)]. In addition, 351 organ donors were stratified into the UE group [n = 106; HBsAg(-), anti-HBc(-), and anti-HBs(-)] or the SC group [n = 245; HBsAg(-), anti-HBc(+), and anti-HBs(+)]. The SNaPshot ddNTP Primer Extension Kit (Applied Biosystems, Foster City, CA) was used for SNP detection. Direct full sequencing of the IL28B coding region was attempted.

Results

Regardless of group, rs12979860 CC was most frequently identified (85.0% in UE, 85.9% in SC, and 93.5% in CC, respectively), whereas rs12979860 TT was not identified in any group. Similarly, rs12980275 AA and rs8099917 TT were most frequently identified (≥85%) regardless of group, whereas rs12980275 GG was identified in only one subject in the SC group. In addition, rs8099917 GG was not identified. The prevalences of CC in rs12979860, AA in rs12980275, and TT in rs8099917 were significantly higher in the CC group when compared with the UE and SC group (all P<0.05). Among 19 novel SNPs in the IL28B coding region, the proportions of 6 SNPs were significantly different among the UE, SC, and CC groups (all P<0.05).

Conclusions

The SNP upstream of IL28B that has the strongest genetic association with HCV recovery has an inverse influence on HBV recovery. Additional studies are needed to understand the mechanisms of this SNP in HBV infection.