Interleukin 28B Gene Polymorphism and Association with Chronic Hepatitis C Therapy Results in Latvia

Increased incidence of cytomegalovirus coinfection in HCV-infected patients with late liver fibrosis is associated with dysregulation of JAK-STAT pathway

Herein, we examined the association between cytomegalovirus (CMV) coinfection and the progression of liver fibrosis in hepatitis C virus (HCV) infection, and investigated the effect of CMV coinfection on JAK-STAT pathway. CMV DNAemia was detected by PCR in DNA from controls (n = 120), and HCV patients with early (F0-F1, n = 131) and late (F2-F4, n = 179) liver fibrosis. By quantitative real time PCR (qRT-PCR), we examined the profile of 8 JAK-STAT transcripts in PBMCs RNA from 90 HCV patients (39 CMV positive and 51 CMV negative), 4 CMV mono-infected patients, and 15 controls. Our results demonstrated higher incidence of CMV in F2-F4 group than in control (OR 5.479, 95% CI 3.033-9.895, p < 0.0001) or F0-F1 groups (OR 2, 95% CI 1.238-3.181, p = 0.005). qRT-PCR showed downregulation of STAT2 (p = 0.006) and IRF7 (p = 0.02) in CMV positive group compared to CMV negative one. The downregulation of STAT2 and IRF7 was mainly in CMV positive patients with late fibrosis compared to CMV negative patients (p = 0.0007 for IRF7 and p = 0.01 for STAT2). Our results are the first to report that CMV coinfection is a possible risk factor for the progression of HCV-induced liver fibrosis, and thereby CMV screening and treatment are important for HCV patients.

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.

Genetic predictors of the response to the treatment of hepatitis C virus infection

The genome-wide association studies have identified a strong association between interleukin 28B (IL28B) gene polymorphisms and the response to treatment in patients with hepatitis C virus (HCV) infection. The aim of the study was to evaluate the association between three most widely studied IL28B gene polymorphisms and the response to antiviral treatment of chronic hepatitis C. We performed the genotyping of the three IL28B gene polymorphisms: rs12979860, rs8099917, and rs12980275 in 72 Caucasian patients with chronic hepatitis C, previously treated with the combination therapy of pegylated interferon alpha (PEGIFN α) and ribavirin (RBV). The patients included in the study had finished the treatment regimen at least 6 months before enrolling in the study. We used the sustained viral response (SVR) for the evaluation of the effectiveness of the antiviral treatment, and it was tested with an assay with a sensitivity of 20 IU/mL. An SVR was achieved in 59.7% (43/72) of the treated patients. The three IL28B gene polymorphisms (CC genotype of rs12979860, TT genotype of rs8099917, and AA genotype of rs12980275) were associated with the SVR (p=0.029, p=0.016, and p=0.028, respectively) in the study patients with chronic hepatitis C treated with the combination therapy of PEGIFN α and RBV. The association of IL28B gene polymorphisms with the treatment response points to the possibility of personalized medicine for the treatment of HCV infection.

Impact of IL28B genetic variation on HCV-induced liver fibrosis, inflammation, and steatosis: a meta-analysis

BACKGROUND & AIMS

IL28B polymorphisms were shown to be strongly associated with the response to interferon therapy in chronic hepatitis C (CHC) and spontaneous viral clearance. However, little is known about how these polymorphisms affect the natural course of the disease. Thus, we conducted the present meta-analysis to assess the impact of IL28B polymorphisms on disease progression.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and the Cochrane Library. Integrated odds ratios (OR) were calculated with a fixed-effects or random-effects model based on heterogeneity analyses.

RESULTS

We identified 28 studies that included 10,024 patients. The pooled results indicated that the rs12979860 genotype CC was significantly associated (vs. genotype CT/TT; OR, 1.122; 95%CI, 1.003-1.254; P = 0.044), and that the rs8099917 genotype TT tended to be (vs. genotype TG/GG; OR, 1.126; 95%CI, 0.988-1.284; P = 0.076) associated, with an increased possibility of severe fibrosis. Both rs12979860 CC (vs. CT/TT; OR, 1.288; 95%CI, 1.050-1.581; P = 0.015) and rs8099917 TT (vs. TG/GG; OR, 1.324; 95%CI, 1.110-1.579; P = 0.002) were significantly associated with a higher possibility of severe inflammation activity. Rs8099917 TT was also significantly associated with a lower possibility of severe steatosis (vs. TG/GG; OR, 0.580; 95%CI, 0.351-0.959; P = 0.034), whereas rs12979860 CC was not associated with hepatic steatosis (vs. CT/TT; OR, 1.062; 95%CI, 0.415-2.717; P = 0.901).

CONCLUSIONS

IL28B polymorphisms appeared to modify the natural course of disease in patients with CHC. Disease progression seems to be promoted in patients with the rs12979860 CC and rs8099917 TT genotypes.

Association study of IL28B: rs12979860 and rs8099917 polymorphisms with SVR in patients infected with chronic HCV genotype 1 to PEG-INF/RBV therapy using systematic meta-analysis

Recently, genome-wide associated studies (GWAS) have identified that host genetics IL28B SNPs rs12979860 and rs8099917 were significantly associated with SVR in patients infected with chronic HCV genotype 1 to PEG-INF/RBV therapy. Results from these studies remain conflicting. We conducted this meta-analysis to estimate the overall association of SVR with rs12979860 and rs8099917. We searched the PubMed, Embase, Scholar Google, ISI Web of Knowledge, and Chinese National Knowledge Infrastructure (CNKI) databases for all articles before July 30, 2012. The odds ratio (OR) corresponding to the 95% confidence interval (CI) was used to assess the association. The statistical heterogeneity among studies was assessed with the I(2) statistics. Begg's test and Egger's test were performed to evaluate the publication bias. Eventually, twenty studies were selected for the meta-analysis. The IL-28B SNPs rs12979860 genotype CC and rs8099917 genotype TT significantly positive associated with SVR in patients infected chronic HCV genotype 1 to PEG-INF/RBV therapy (OR=4.473, 95% CI=3.814-5.246, OR=5.171, 95% CI=4.372-6.117 respectively). The results suggested that rs12979860 genotype CC and rs8099917 genotype TT could be used as independent predictors of the HCV-1 infected patients.

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.