Role of interleukin 28B rs12979860 C/T polymorphism on the histological outcome of chronic hepatitis C: relationship with gender and viral genotype

Interleukin-28 and hepatitis C virus genotype-4: treatment-induced clearance and liver fibrosis

AIM

To investigate the association between interleukin-28B (IL28B) genotype and response to treatment and hepatic fibrosis in patients with hepatitis C virus (HCV) genotype 4.

METHODS

Two hundred and one HCV-genotype 4 patients were included. All patients were treated with Peginterferon alph2a/Ribavirin for 48 wk. End of treatment response (ETR) was defined as loss of detectable serum HCV RNA at the end of treatment. Sustained viral response (SVR) was defined as loss of detectable serum HCV RNA at the end of 24 wk follow up. Genotyping of IL28B rs12979860 was performed using the TaqMan assay. We used logistic regression to estimate the adjusted odds ratio (aOR) and 95%CI.

RESULTS

The study included 201 HCV-genotype 4 patients. The majority of patients were men (89.6%), with a median age of 47 years, inter-quartile range (40-51). Approximately 62.5% of patients had ETR, and 49.6% had SVR. Individuals who achieved SVR were more likely to be younger (χ(2) = 4.91, P = 0.027), and less likely to have fibrosis (χ(2) = 15.54, P < 0.0001), or inflammation (χ(2) = 7.58, P = 0.006). The genotype distribution of rs12979860 was 36.2%, 49.0% and 14.8% for genotypes CC, CT, and TT, respectively. In these participants, rs12979860 genotype distribution did not differ by gender (P = 0.466), pretreatment viral load (P = 0.600), inflammation (P = 0.435), or fibrosis (P = 0.291). The frequencies of IL28B rs12979860 genotypes were TT (14.8%), CT (49.0%), and CC (36.2%). Compared to rs12979860 genotype TT, aORs (95%CI) for ETR and SVR were: CC genotype, [17.55 (5.34-57.69) and 5.92 (2.09-16.76), respectively]; CT genotype, [5.15 (1.80-14.78) and 2.48 (0.94-6.52), respectively]. In the current study, the patients who did not achieve ETR or SVR had a lower prevalence of rs12979860 CC (17.4% and 23.3%, respectively) than individuals who had ETR or SVR (47.9% and 47.2%, respectively). Individuals with rs12979860 CC genotype had approximately 6 times the odds of SVR compared to individuals with TT genotype (aOR = 5.92; 95%CI: 2.09-16.76). Similarly, patients with CT genotype had SVR more often than patients with TT genotype (aOR = 2.48; 95%CI: 0.94-6.52). Carrying at least one copy of the C allele (genotypes CT and CC) had almost 8 times the probability of ETR compared to those with genotype rs12979860 TT (aOR = 7.87; 95%CI: 2.84-21.82), and approximately 3 times the odds of SVR compared to those with genotype rs12979860 TT (aOR = 3.46; 95%CI: 1.37-8.74). In addition, data were consistent with a significant gene-dose relationship (aOR = 4.05/allele; 95%CI: 2.27-7.22). The association between rs12979860 genotype and SVR was similar among those who achieved and those who did not achieve SVR.

CONCLUSION

In HCV-genotype 4 patients, rs12979860 is a sensitive predictor of viral clearance, independent of viral load, age, gender or fibrosis, with no similar relation to severity of fibrosis.

Host genetic variants in the pathogenesis of hepatitis C

Direct-acting antiviral drugs (DAAs) are currently replacing antiviral therapy for Hepatitis C infection. Treatment related side effects are even worse and the emergence of resistant viruses must be avoided because of the direct-antiviral action. Altogether it remains a challenge to take treatment decisions in a clinical setting with cost restrictions. Genetic host factors are hereby essential to implement an individualized treatment concept. In recent years results on different genetic variants have been published with a strong association with therapy response, fibrosis and treatment-related side effects. Polymorphisms of the IL28B gene were identified as accurate predictors for therapy response and spontaneous clearance of HCV infection and are already used for diagnostic decisions. For RBV-induced side effects, such as hemolytic anemia, associations to genetic variants of inosine triphosphatase (ITPA) were described and different SLC28 transporters for RBV-uptake have been successfully analyzed. Fibrosis progression has been associated with variants of Vitamin D receptor (VDR) and ABCB11 (bile salt export pump). Cirrhotic patients especially have a high treatment risk and low therapy response, so that personalized antiviral treatment is mandatory. This review focuses on different host genetic variants in the pathogenesis of Hepatitis C at the beginning of a new area of treatment.

Lower liver-related death in African-American women with human immunodeficiency virus/hepatitis C virus coinfection, compared to Caucasian and Hispanic women

Among individuals with and without concurrent human immunodeficiency virus (HIV), racial/ethnic differences in the natural history of hepatitis C virus (HCV) have been described. African Americans have lower spontaneous HCV clearance than Caucasians, yet slower rates of liver fibrosis once chronically infected. It is not clear how these differences in the natural history of hepatitis C affect mortality, in either HIV-positive or -negative individuals. We conducted a cohort study of HIV/HCV coinfected women followed in the multicenter Women's Interagency HIV Study to determine the association of self-reported race/ethnicity with all-cause and liver-related mortality. Survival analyses were performed using Cox's proportional hazards models. The eligible cohort (n = 794) included 140 Caucasians, 159 Hispanics, and 495 African Americans. There were 438 deaths and 49 liver-related deaths during a median follow-up of 8.9 years and maximum follow-up of 16 years. African-American coinfected women had significantly lower liver-related mortality, compared to Caucasian (hazard ratio [HR], 0.41; 95% confidence interval [CI]: 0.19-0.88; P = 0.022) and Hispanic coinfected women (HR, 0.38; 95% CI: 0.19-0.76; P = 0.006). All-cause mortality was similar between racial/ethnic groups (HRs for all comparisons: 0.82-1.03; log-rank test: P = 0.8).

CONCLUSIONS

African-American coinfected women were much less likely to die from liver disease, as compared to Caucasians and Hispanics, independent of other causes of death. Future studies are needed to investigate the reasons for this marked racial/ethnic discrepancy in liver-related mortality.

Genetic polymorphism in cyclooxygenase-2 promoter affects hepatic inflammation and fibrosis in patients with chronic hepatitis C

Cyclooxygenase (COX)-2 is involved in inflammation, anti-apoptosis and carcinogenesis. The -1195GG genotype of single nucleotide polymorphism (SNP) in COX-2 promoter was associated with low platelet counts in patients with chronic hepatitis C. Polymorphism of patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene (rs738409 C>G) have been reported to be associated with cirrhosis, and the major genotype of SNPs near interleukin (IL)28B are related to viral clearance. The present study was designed to assess the contribution of these SNPs to disease progression in patients with chronic hepatitis C. The study enrolled 220 Japanese patients with chronic hepatitis C. Three SNPs, -1195 COX-2, PNPLA3 and IL28B (rs8099917), were genotyped in order to analyze their association with hepatic fibrosis and inflammation. The -1195GG genotype in COX-2 was associated with advanced fibrosis and higher levels of inflammation in the liver tissues. The major genotype of IL28B was also associated with advanced fibrosis, but the polymorphism of PNPLA3 was neither associated with fibrosis nor inflammation. Multivariate analysis showed that -1195GG in COX-2 is an independent factor associated with advanced fibrosis, while the major genotype of IL28B and HCV genotype 2 were other independent factors. In conclusion, the -1195GG genotype in COX-2 is a genetic marker for liver disease progression, while the PNPLA3 genotypes are not associated with disease progression in Japanese patients with chronic hepatitis C.

Closed tube method for rapid screening of IL28B polymorphisms involved in response to hepatitis C treatment

BACKGROUND & AIM

Hepatitis C is a liver disease caused by the hepatitis C virus. Interferon and ribavirin combination therapy has been a standard treatment of chronic hepatitis C. But only about 50% of patients have positive response to treatment and achieve so called sustained virological response. Recent studies indicate association of several single nucleotide polymorphisms near IL28B gene and response of hepatitis C patients to combined interferon/ribavirin treatment. In this study, rapid, specific and cost-effective small amplicon genotyping method for the two clinically important polymorphisms, rs12979860 C > T and rs8099917 T > G, near the IL28B gene is described.

METHODS

The distribution of genotypes of 181 HCV-uninfected Slovak Caucasians was analyzed using this novel method, based on a real-time melting analysis of the small amplicon.

RESULTS AND CONCLUSIONS

The frequency of wild-type (TT) homozygotes for rs8099917 was 66.30%, frequency of heterozygotes (TG) was 30.94% and we found only 2.76% subjects homozygous for risk G allele (allelic frequencies: T = 81.77%, G = 18.23%) were found. The frequency of wild-type genotype (CC) for rs12979860 was 49.72%, frequencies of heterozygous (CT) and risk-allele homozygous genotypes (TT) were 39.78% and 10.50%, respectively (allele frequencies: C = 69.61%, T = 30.39%). Statistically significant differences in the distribution of the alleles between the men and the women were not found. The novel method developed in our laboratory proved to be simple and highly customizable.

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.

IL28B and PNPLA3 polymorphisms affect histological liver damage in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

Genetic background may affect liver damage in patients with non-alcoholic fatty liver disease (NAFLD). The main outcomes of the study were to assess whether IL28B rs12979860 and rs8099917 polymorphisms, together with PNPLA3 rs738409 C>G polymorphism, are associated with lobular inflammation and fibrosis, in NAFLD patients.

METHODS

One hundred sixty consecutive NAFLD patients were assessed by liver biopsy (Kleiner score); anthropometric, and biochemical and metabolic features were included. IL28B rs12979860 C>T, IL28B rs8099917 G>C, and PNPLA3 rs738409 C>G single nucleotide polymorphisms were tested.

RESULTS

Seventy-four (46.2%) patients had IL28B rs12979860 CC polymorphism, compared with 72 (45%) and 14 (8.8%) with TC and TT variants, respectively. PNPLA3 rs738409 CC polymorphism was present in 47 (29.4%) patients, compared with 79 (49.4%) and 34 (21.3%) with CG and GG variants, respectively. Multivariate logistic regression analysis showed that age (OR 1.043, 95% CI 1.012-1.075, p=0.007), triglycerides (OR 1.005, 95% CI 1.000-1.010, p=0.04), hyperuricemia (OR 5.027, 95% CI 1.839-13.742, p=0.002), IL28B rs12979860 TT/TC (OR 0.219, 95% CI 0.101-0.472, p<0.001), and steatosis grade (OR 1.704, 95% CI 1.048-2.773, p=0.03) were independently linked to moderate-severe lobular inflammation. Finally, IL28B rs12979860 CC was associated with severe fibrosis (F3-F4) on univariate analysis, even if only older age (OR 1.064, 95% CI 1.026-1.104, p=0.001), high HOMA (OR 1.213, 95% CI 1.068-1.377, p=0.003), and lobular inflammation (OR 3.181, 95% CI 1.438-7.036, p=0.004), remained associated in multivariate logistic regression analysis.

CONCLUSIONS

In NAFLD patients, IL28B rs12979860 CC genotype, together with PNPLA3 rs738409 GG, is associated with the severity of liver damage.

Genetics of IL28B and HCV--response to infection and treatment

The IL28B locus attracted the attention of HCV researchers after a series of genome-wide association studies independently identified a strong association between common IL28B polymorphisms and the outcome of PEG-IFN-α plus ribavirin combination therapy in patients chronically infected with HCV genotype 1. This association was subsequently replicated for other HCV genotypes and has been linked to spontaneous eradication of HCV, development of steatosis and biochemical changes (such as altered levels of γ-glutamyl transpeptidase and LDL). Despite the introduction of direct-acting antiviral drugs, IL28B genetics are likely to play a part in patient selection and treatment decisions-moving towards a personalized approach to therapy. In HCV-infected patients with the so-called favourable IL28B genotype (rs12979860 CC; associated with better treatment response), hepatic expression levels of IL28B and interferon-stimulated genes seem to be reduced at baseline, but are induced more strongly after IFN-α administration, perhaps resulting in more effective elimination of the virus. Clarification of the mechanisms underlying these biological phenomena will lead to improved understanding of the antiviral effects of IFN-λ and, ideally, to the development of better therapies against HCV infection. This Review summarizes current understanding of the role of IL28B in HCV infection and response to therapy.

Relation of IL28B gene polymorphism with biochemical and histological features in hepatitis C virus-induced liver disease

BACKGROUND/AIMS

Polymorphism at the IL28B gene may modify the course of hepatitis C virus (HCV) chronic infection. Our aim was to study the influence of IL28B rs12979860 gene polymorphism on the biochemistry and pathology of HCV-induced disease in the clinical course from mild chronic hepatitis C to hepatocellular carcinoma.

METHODS

We have determined the rs12979860 single nucleotide polymorphism (SNP) upstream IL28B gene in two groups of patients with HCV-induced chronic liver disease: 1) 268 patients (159 men) with biopsy-proven chronic hepatitis C, to analyse its relation with biochemical, virological and histological features; and 2) 134 patients (97 men) with HCV-related hepatocellular carcinoma. The distribution of the analysed SNP in hepatocellular carcinoma patients was compared with that found in untreated chronic hepatitis C patients. All patients were white and most were Spaniards.

RESULTS

In multivariate analysis ALT values were higher (P = 0.001) and GGT values were lower (P<0.001) in chronic hepatitis C patients homozygotes for the major rs12979860C allele as compared with carriers of the mutated rs12979860T allele. Steatosis was more frequent (Odds ratio = 1.764, 95% C.I. 1.053-2.955) and severe (P = 0.026) in carriers of the rs12979860T allele. No relation was found between the analysed SNP and METAVIR scores for necroinflammation and fibrosis, and there were no differences in the distribution of the analysed SNP between hepatocellular carcinoma and untreated chronic hepatitis C patients.

CONCLUSION

The IL28B rs12979860 polymorphism correlates with the biochemical activity and the presence and severity of liver steatosis in chronic hepatitis C.

IL28B polymorphisms influence stage of fibrosis and spontaneous or interferon-induced viral clearance in thalassemia patients with hepatitis C virus infection

BACKGROUND

Polymorphisms in the interleukin-28B are important determinants in the spontaneous and drug-induced control of hepatitis C virus infection.

DESIGN AND METHODS

We assessed the association of rs8099917 and rs12979860 polymorphisms with spontaneous viral clearance, severity of liver fibrosis, and response to interferon-monotherapy in 245 thalassemia major patients with hepatitis C virus infection.

RESULTS

Ninety-eight patients (40%) had a spontaneous viral clearance while 147 patients (60%) developed a chronic infection. Spontaneous viral clearance was more frequent among patients with the T/T genotype of rs8099917 polymorphism (OR 2.130; P = 0.008) or C/C genotype of rs12979860 polymorphism (OR 2.425; P = 0.001). During observation, 131 patients with chronic infection underwent a liver biopsy; age (OR 1.058; P = 0.01) G/T or G/G genotypes of rs8099917 polymorphism (OR 3.962; P = 0.001), and C/T or T/T genotypes of rs12979860 polymorphism (OR 3.494; P = 0.005) were associated with severe liver fibrosis, independent of liver iron concentration. Finally, T/T genotype of rs8099917 polymorphism (OR 3.014; P = 0.03) or C/C genotype of rs12979860 polymorphism (OR 3.285; P = 0.01), age (OR 0.902; P = 0.001), female gender (OR 3.418; P = 0.01) and 2 or 3 virus C genotypes (OR 4.700; P=0.007) were independently associated with sustained virological response in 114 patients treated with alpha-interferon. Conclusions Polymorphisms in the interleukin-28B are associated with the control of hepatitis C virus infection in thalassemia major patients, and understanding allelic patterns has an important role in determining prognosis and therapeutic management.

Female sex and IL28B, a synergism for spontaneous viral clearance in hepatitis C virus (HCV) seroconverters from a community-based cohort

BACKGROUND & AIMS

Since acute hepatitis C virus (HCV) infection is often asymptomatic, it is difficult to examine the rate and determinants of spontaneous clearance. Consequently, these studies are subject to bias, which can potentially lead to biased rates of viral clearance and risk estimates. We evaluated determinants of spontaneous HCV clearance among HCV seroconverters identified in a unique community-based cohort.

METHODS

Subjects were 106 drug users with documented dates of HCV seroconversion from the Amsterdam Cohort Study. Logistic regression was used to examine sociodemographic, behavioral, clinical, viral and host determinants, measured around acute infection, of HCV clearance.

RESULTS

The spontaneous viral clearance rate was 33.0% (95% confidence interval (CI) 24.2-42.8). In univariate analyses female sex and fever were significantly associated with spontaneous clearance. The favorable genotypes for rs12979860 (CC) and rs8099917 (TT) were associated with spontaneous clearance, although borderline significant. In multivariate analysis, females with the favorable genotype for rs12979860 (CC) had an increased odds to spontaneously clear HCV infection (adjusted OR 6.62, 95% 2.69-26.13), whereas females with the unfavorable genotype were as likely as men with the favorable and unfavorable genotype to clear HCV. Chronic Hepatitis B infection and absence of HIV coinfection around HCV seroconversion also favor HCV clearance.

CONCLUSIONS

This study shows that co-infection with HIV and HBV and genetic variation in the IL28B region play an important role in spontaneous clearance of HCV. Our findings suggest a possible synergistic interaction between female sex and IL28B in spontaneous clearance of HCV.