Genes and hepatitis C: susceptibility, fibrosis progression and response to treatment

Exportin 4 DNA promoter methylation in liver fibrosis

A role for exportin 4 (XPO4) in the pathogenesis of liver fibrosis was recently identified. We sought to determine changes in hepatic XPO4 promoter methylation levels during liver fibrosis. The quantitative real-time RT-PCR technique was used to quantify the mRNA level of XPO4. Additionally, pyrosequencing was utilized to assess the promoter methylation status of XPO4. The methylation rate of the XPO4 promoter was significantly increased with fibrosis in human and mouse models, while XPO4 mRNA expression negatively correlated with methylation of its promoter. DNA methyltransferases (DNMTs) levels (enzymes that drive DNA methylation) were upregulated in patients with liver fibrosis compared to healthy controls and in hepatic stellate cells upon transforming growth factor beta (TGFβ) stimulation. The DNA methylation inhibitor 5-Aza or specific siRNAs for these DNMTs led to restoration of XPO4 expression. The process of DNA methylation plays a crucial role in the repression of XPO4 transcription in the context of liver fibrosis development.

Impact of IL-10 gene promoter polymorphisms on treatment response in HCV patients: A systematic review, a meta-analysis, and a meta-regression

The impact of interleukin-10 (IL-10) gene promoter polymorphisms (SNPs) on treatment response in HCV patients was dissimilarly estimated. Hence, the aim of this meta-analysis was to robustly assess the effect of IL-10 SNPs on treatment response in HCV patients. An electronic literature search was carried out through PubMed, EMBASE, Web of science, and Scopus databases. Studies assessing the association between IL-10 polymorphisms and treatment response in HCV patients were included. Studies were excluded if genotype frequencies are not consistent with the Hardy-Weinberg Equilibrium (HWE) or in case of including patients with hepatitis B virus coinfection. Risk of bias in included studies was assessed using the Newcastle-Ottawa Scale. Meta-analyses were performed for the influence of IL-10 gene promoter SNPs (rs1800896 (-1082 A/G), rs1800871 (-819 C/T), and rs1800872 (-592 C/T)) and haplotypes on treatment response in HCV patients. Subgroup analyses, meta-regressions, publication bias assessment, and sensitivity analyses were also conducted. Overall, 32 studies with a total of 5943 HCV cases and 2697 controls were included in the present study. The -1082*G allele was significantly associated with increased risk of non-response (NR) to treatment, OR [95% CI] = 1.29 [1.1-1.51], p = .002. Besides, the rs1800872 -592*C allele was significantly associated with increased NR risk, OR [95% CI] = 1.22 [1.02-1.46], p = .03. Subgroup analysis showed that this association remained significant only in patients treated with PEG-IFN alone, p = .01. The -1082*G/-819*C/-592*C (GCC) haplotype was significantly associated with increased NR risk, OR [95% CI] = 1.62 [1.13-2.23], p = .009. Our results suggest that the IL-10 rs1800896 was associated with NR risk especially in North-African and Asian populations. Moreover, the IL-10 gene promoter -1082*G/-819*C/-592*C (GCC) haplotype which has been associated with higher production of IL-10, was significantly associated with increased NR risk.

Impact of IL-28B gene polymorphism on chronic hepatitis-C patients progression with diabetes and non-diabetes

Background

Chronic hepatitis C (CHC) is a silent viral infection; however, elevated mortality and morbidity rates are noted in Egypt due to its adverse effects. The augmented incidence of diabetes in patients with viral C infection may be owing to glucose intolerance, high BMI, senility, and inherited factors.

Purpose of the study

Little information is available about the connection between interleukin-28B (IL-28B) genotype in disease progression among CHC patients with diabetes. Thus, we aimed to assess the association between IL-28B genotype (rs12979860) in CHC with type 2 diabetes mellitus (T2DM) versus those without diabetes in disease progression among Egyptian patients.

Results

CC genotype was significantly lower in diabetics than in non-diabetics (13.7% vs. 36.3%). While (CT/TT) were significantly higher in diabetics than in non-diabetics (CT 58.8% vs. 43.7%), (TT 27.5% vs. 20%) (p = 0.03) and likewise alleles (p = 0.04). Multivariate logistic regression analysis was significant with viral load p < 0.001, alanine aminotransferase (ALT) p < 0.001, genotype CC versus TT p = 0.04 & T2DM p = 0.03.

Conclusion

CC genotype might be used as a protective factor and TT genotype as a risk factor in disease progression among CHC patients with T2DM. Additionally, viral load, ALT & T2DM might interplay as predictors of disease severity. Detecting the genetic factors can be helpful in predicting and preventing the complications of diabetes associated with the hepatitis C virus (HCV).

Breakthroughs in hepatitis C research: from discovery to cure

In the 1970s, an unknown virus was suspected for documented cases of transfusion-associated hepatitis, a phenomenon called non-A, non-B hepatitis. In 1989, the infectious transmissible agent was identified and named hepatitis C virus (HCV) and, soon enough, the first diagnostic HCV antibody test was developed, which led to a dramatic decrease in new infections. Today, HCV infection remains a global health burden and a major cause of liver cirrhosis, hepatocellular carcinoma and liver transplantation. However, tremendous advances have been made over the decades, and HCV became the first curable, chronic viral infection. The introduction of direct antiviral agents revolutionized antiviral treatment, leading to viral eradication in more than 98% of all patients infected with HCV. This Perspective discusses the history of HCV research, which reads like a role model for successful translational research: starting from a clinical observation, specific therapeutic agents were developed, which finally were implemented in national and global elimination programmes.

Association of the 3' untranslated region polymorphisms of HLA-G with susceptibility to chronic hepatitis C virus infection in the Chinese population

Hepatitis C virus (HCV) infection is a global health problem. Several previous studies have addressed the role of host single-nucleotide polymorphisms (SNPs) in HCV infection. SNPs in the regulatory region of the human leukocyte antigen G (HLA-G) gene play an important role in several diseases. The objective of this study is to determine the association of HLA-G 3'untranslated region (UTR) polymorphisms with the susceptibility to chronic hepatitis C infection in the Chinese population. HLA-G 3' UTR polymorphisms, which include 14-bp Ins/Del (rs371194629), +3003T/C (rs1707), +3010C/G (rs1710), +3027 A/C (rs17179101), +3035C/T (rs17179108), +3142 G/C (rs1063320), +3187 A/G (rs9380142) and + 3196C/G (rs1610696), were analyzed in 246 patients with chronic hepatitis C infection and 294 healthy individuals. The alleles, genotypes, and haplotypes were compared between chronic hepatitis C-infected subjects and controls using chi-square tests and logistic regression models. After a correction of multiple comparisons by the false discovery rate (FDR), the allele frequency of + 3196C, genotype frequencies of + 3187 AA and + 3196CC and frequency of the UTR-3 haplotype were significantly higher in the patients than in the control group (P < 0.05), whereas the frequencies of UTR-1 and UTR-2 haplotypes were significantly lower in the patients than in the control group (P < 0.05). After a correction of multiple comparisons by FDR, UTR-2 and UTR-3 maintained significant associations with chronic hepatitis C. This study indicates that HLA-G 3'UTR polymorphisms are associated with the susceptibility to chronic hepatitis C infection in the Chinese population. HLA-G 3'UTR may play an important role in risk modulation toward HCV infection.

Interferon-λ rs12979860 genotype association with liver fibrosis in chronic hepatitis C (CHC) patients in the Pakistani population

Risk and progression of liver fibrosis and cirrhosis in chronic hepatitis C (CHC) patients is significantly influenced by host genetic factors in a polygenic manner. The rs12979860 genetic polymorphism in the interferon-λ3-interferon-λ4 (IFNL3-IFNL4) region has been found to be a major determinant of hepatic inflammatory and fibrotic progression in CHC patients of mainly Caucasian origin; however, it is not known if this association applies to other ethnicities, including Pakistani CHC patients. Here, we genotyped IFNL3-IFNL4 rs12979860 genetic variants in a sample set of 502 Pakistani patients with CHC and used logistic regression analysis to determine its association with the risk and progression of HCV-related fibrosis and cirrhosis. We demonstrate that the rs12979860 major (CC) genotype, despite not determining the risk of stage-specific hepatic fibrosis independently, is associated with a marginally significant risk of liver cirrhosis (OR: 1.64, p = 0.049) after an adjustment for age, gender, body mass index, HCV viral load, and liver enzymes. In a subgroup of CHC patients with sustained ALT levels of <60 IU/L, a more pronounced impact of the IFNL3-IFNL4 rs12979860 major (CC) genotype on advanced liver fibrosis (OR: 4.99, p = 0.017) and cirrhosis (OR: 3.34, p = 0.005) was seen. The present study suggests that IFNL3-IFNL4 rs12979860 polymorphism may also be a significant predictor of hepatic fibrosis and cirrhosis in Pakistani CHC patients, especially in those with normal or near-normal liver enzyme levels.

Association of human platelet antigens polymorphisms with the levels of serum fibrosis marks in chronic hepatitis C patients

BACKGROUND

Host genetic polymorphisms influence the fibrosis progression of chronic hepatitis C (CHC) patients. Previous studies have shown the association of human platelet antigens (HPAs) polymorphisms with CHC. However, little is known regarding the association of HPAs polymorphisms with the fibrosis progression of CHC. The aim of this study was to determine the association of HPA -2, -3, -5 and -15 polymorphisms with the levels of serum fibrosis marks in CHC patients.

METHODS

The HPA -2, -3, -5 and -15 were genotyped by 5'-nuclease assay in 211 CHC patients, while the serum concentration of hyaluronic acid (HA), collagen IV (CIV), amino-terminal pro-peptide of type III procollagen (PIIINP), and laminin (LN) from the same samples were measured by time resolved fluorescence immunoassay.

RESULTS

The level of serum LN was significantly lower in CHC patients with HPA-15aa genotype compared to those with HPA-15ab/bb (P = 0.032) but did not differ among HPA-2, -3 and -5 genotypes. There were no difference in HA, CIV and PIIINP levels among HPA-2, -3,-5 and -15 genotypes.

CONCLUSIONS

This study demonstrates that HPA-15 aa polymorphism is associated lower serum LN in CHC, which suggests that HPA -15 aa may be involved in the fibrosis progression of CHC.

The STAT4 and not the IFNL3 variant is associated with hepatitis B virus clearance in a population from the Khyber Pakhtunkhwa region of Pakistan

BACKGROUND AND STUDY AIMS

Host genetic modifiers of the risk and persistence of hepatitis B virus (HBV) infection in the Pakistani population have not been clearly elucidated. Recently, two genome-wide association studies described that STAT4 and IFNL3 variants are associated with different aspects of the course of HBV infection. However, the roles of these variants in the persistence of HBV infection have not been investigated in the HBV-infected population of Pakistan. Therefore, we examined the roles of the STAT4 and IFNL3 variants in a chronic HBV-infected population from the Khyber Pakhtunkhwa (KPK) region of Pakistan.

PATIENTS AND METHODS

STAT4 rs7574865 and IFNL3 rs12979860 genotyping were performed in 297 subjects (240 infected with HBV and 57 controls). Statistical analyses were performed using the chi-squared test, Student's t-test, Hardy-Weinberg equilibrium tests and logistic regression models.

RESULTS

Among the 297 subjects, compared with the IFNL3 rs12979860 genotype [odds ratio (OR) = 0.7, 95% confidence interval (CI) = 0.39-1.29, p = 0.2), the STAT4 rs7574865 genotype was independently associated with the risk of developing chronic HBV infection [OR = 1.9, 95% CI = 1.09-3.50, p = 0.02].

CONCLUSION

The STAT4 rs7574865 and not the IFNL3 rs12979860 variant is associated with persistence of HBV infection in a Pakistani population from the KPK region.

A variant in the MICA gene is associated with liver fibrosis progression in chronic hepatitis C through TGF-β1 dependent mechanisms

Hepatocarcinogenesis is tightly linked to liver fibrosis. Recently, two GWAS variants, MICA rs2596542 and DEPDC5 rs1012068 were identified as being associated with the development of HCV-induced hepatocellular carcinoma (HCC) in Japanese patients. The role of these variants on hepatic inflammation and fibrosis that are closely associated with HCC development is not known, nor are the biological mechanisms underlying their impact on the liver. Here, we demonstrate in 1689 patients with chronic hepatitis C (CHC) (1,501 with CHC and 188 with HCV-related HCC), that the MICA (T) allele, despite not being associated with HCC susceptibility, is associated with increased fibrosis stage (OR: 1.47, 95% CI: 1.05–2.06, p = 0.02) and fibrosis progression rate (hazards ratio: 1.41, 95% CI: 1.04–1.90, p = 0.02). The DEPDC5 variant was not associated with any of these phenotypes. MICA expression was down-regulated in advanced fibrosis stages. Further, (T) allele carriage was associated with lower MICA expression in liver and serum. Transforming growth factor-β1 (TGF-β1) expression suppresses MICA expression in hepatic stellate cells. Our findings suggest a novel mechanism linking susceptibility to advanced fibrosis and subsequently indirectly to HCC, to the level of MICA expression through TGF-β1-dependent mechanisms.

Polymorphisms in the Th17 cell-related RORC gene are associated with spontaneous clearance of HCV in Chinese women

BACKGROUND

Female gender and favorable IFNL3 genotypes are the primary independent predictors of spontaneous clearance of HCV infection. However, chronic hepatitis C infection occurs in numerous women carrying favorable IFNL3 genotypes, indicating that other host and/or virological factors contribute to the prognosis of infection.

METHODS

A cohort of 137 anti-HCV-positive female Han Chinese cases, including 64 chronic HCV carriers and 73 HCV spontaneous resolvers, was recruited in the study. 111 SNPs in 23 genes encoding HCV co-receptors, transcription factors, Toll-like receptors, co-stimulating molecules, and cytokines were selected for SNP analysis.

RESULTS

After comparison of genotypes and allelotype frequencies of 111 SNPs in 23 genes in the primary cohort, the SNPs rs9826 (P = 0.024 for CC/TT/CT; P = 0.015 for C allele/T allele) and rs1521177 (P = 0.017 for GG/TT/GT; P = 0.006 for G allele/T allele) in the RORC gene were significantly associated with spontaneous HCV clearance. In the sub-cohort carrying favorable IFNL3 genotypes (rs12979860CC, rs8099917 TT, rs12980275 AA), rs1521177 (genotype: P = 0.040; allelotype: P = 0.021) remained significantly associated with spontaneous HCV clearance. Importantly, the most common RORC haplotype rs9826-T/rs1521177-T was presented at significantly different frequencies in resolvers and carriers in both the primary cohort (P = 0.0027) and the IFNL3 favorable sub-cohort (P = 0.0117).

CONCLUSIONS

This study indicates that genetic polymorphisms in human Th17-related RORC gene are associated with different natural prognosis of HCV infection. The RORC haplotype, rs9826-T/rs1521177-T, was favorable for spontaneous clearance of HCV 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.

A systematic review and meta-analysis of HCV clearance

While hepatitis C exemplifies the role of host genetics in infectious diseases outcomes, there is no comprehensive overview of polymorphisms influencing spontaneous and/or treatment-induced hepatitis C virus clearance. We performed a systematic review and meta-analysis of host polymorphisms associated with these phenotypes. Literature search was conducted using combinations of keywords in three databases. Studies were reviewed and relevant data systematically extracted for subsequent meta-analyses. Polymorphisms from candidate gene studies were tested in two cohorts of HCV-infected patients with available genomic data. The literature search yielded 8'294 citations, among which 262 studies were selected. In the meta-analysis of 27 HLA studies, the most significant associations with spontaneous hepatitis C virus clearance included DQB1*02, DQB1*03, DRB1*04 and DRB1*11. In the meta-analysis of 16 studies of KIR genes and their HLA-ligands, KIR2DS3 was associated with both spontaneous and treatment-induced clearance, and the HLA-C2 ligand with failure to spontaneously clear the virus. In a pooled analysis of 105 candidate genes and two genome-wide association studies, we observed associations of single nucleotide polymorphisms from nine genes (EIF2AK2, IFNAR2, ITPA, MBL2, MX1, OASL, SPP1, TGFB1, TNK2) with response to interferon-based therapy. Meta-analysis of 141 studies confirmed the association of IFNL3/4 polymorphisms with spontaneous and treatment-induced hepatitis C virus clearance, even in previously underpowered groups, such as hepatitis C virus genotypes 2/3-infected patients. This study may contribute to a better understanding of hepatitis C virus immunopathogenesis and highlights the complex role of host genetics in hepatitis C virus clearance.

Association of human platelet antigens polymorphisms with susceptibility to hepatitis C virus infection in Chinese population

Hepatitis C virus (HCV) is a major cause of chronic hepatitis. Previous studies have identified a number of single nucleotide polymorphisms that are associated with HCV infection. Human platelet antigens (HPAs) polymorphisms play an important role in several diseases. Here, we demonstrated the association of the HPA-2, HPA-3, HPA-5 and HPA-15 polymorphisms with susceptibility to HCV infection in Chinese population. Overall, 118 patients with HCV and 167 controls were genotyped for HPAs. There were no significant differences in the allele and genotype frequency distribution for the HPA-3, HPA-5 and HPA-15 systems between the patients with chronic HCV infection and the healthy controls (p > .05). However, the genotype frequency of HPA-2aa was significantly lower, while HPA-2ab/bb was significantly higher in patients than that in the controls (p = .006). The allele frequency of HPA-2a in patients was significantly lower than that in the control group (p = .005). In contrast, HPA-2b in patients was significantly higher than that in the control group (p = .005). We conclude that HPA-2 polymorphism is associated with susceptibility to HCV infection, and individuals carrying the HPA-2b allele may have a higher risk of HCV infection compared with individuals carrying HPA-2a.

A prognostic model for development of significant liver fibrosis in HIV-hepatitis C co-infection

BACKGROUND

Liver fibrosis progresses rapidly in HIV-Hepatitis C virus (HCV) co-infected individuals partially due to heightened inflammation. Immune markers targeting stages of fibrogenesis could aid in prognosis of fibrosis.

METHODS

A case-cohort study was nested in the prospective Canadian Co-infection Cohort (n = 1119). HCV RNA positive individuals without fibrosis, end-stage liver disease or chronic Hepatitis B at baseline (n = 679) were eligible. A random subcohort (n = 236) was selected from those eligible. Pro-fibrogenic markers and Interferon Lambda (IFNL) rs8099917 genotype were measured from first available sample in all fibrosis cases (APRI ≥ 1.5 during follow-up) and the subcohort. We used Cox proportional hazards and compared Model 1 (selected clinical predictors only) to Model 2 (Model 1 plus selected markers) for predicting 3-year risk of liver fibrosis using weighted Harrell's C and Net Reclassification Improvement indices.

RESULTS

113 individuals developed significant liver fibrosis over 1300 person-years (8.63 per 100 person-years 95% CI: 7.08, 10.60). Model 1 (age, sex, current alcohol use, HIV RNA, baseline APRI, HCV genotype) was nested in model 2, which also included IFNL genotype and IL-8, sICAM-1, RANTES, hsCRP, and sCD14. The C indexes (95% CI) for model 1 vs. model 2 were 0.720 (0.649, 0.791) and 0.756 (0.688, 0.825), respectively. Model 2 classified risk more appropriately (overall net reclassification improvement, p<0.05).

CONCLUSIONS

Including IFNL genotype and inflammatory markers IL-8, sICAM-1, RANTES, hs-CRP, and sCD14 enabled better prediction of the 3-year risk of significant liver fibrosis over clinical predictors alone. Whether this modest improvement in prediction justifies their additional cost requires further cost-benefit analyses.

A systematic review of treatment response rates in Pakistani hepatitis C virus patients; current prospects and future challenges

BACKGROUND

The estimated hepatitis C virus (HCV) carriers are approximately 10 million in Pakistan which usually progresses to chronic hepatitis, with rare cases of spontaneous viral eradication. The present article reviews the treatment status of HCV infection in Pakistani population and various factors associated with the treatment response rates.

METHODS

Literature on anti-HCV therapy was searched in PubMed, Google Scholar and PakMediNet. Thirty three different studies representing different geographic regions of Pakistan published from 2002 to 2016 were included in the present review. Weighted mean, standard error estimates (SE) and standard deviation (SD) were determined for each population group.

RESULTS

Mean value for sustained virological response (SVR) for standard IFN plus ribavirin (RBV) combination therapy was 68.38% ± 14.13% (range 33.8%-87.10%; SE 3.08) and pegylated-IFN plus RBV combination therapy 64.38% ± 8.68% (range 55.0%-76.00%; SE 3.88). The lowest value for SVR has been reported to be 24.3% (for genotype 1; administering INF-α 2b 3MU 3 times/week and RBV 1000-1200 mg/day for 48 weeks) while highest of 87.5% (genotype 3a; INF-α 2a 3MU 3 times/week and RBV 1000-1200 mg/day for 24 weeks). The mean value for rapid virological response (RVR) was found to be 48.18% ± 29.20% (SE 9.73). As PEG-interferon and direct acting antivirals (DAAs) are relatively expensive, interferon-alfa (IFN-α) and RBV combination therapy have been used widely to treat HCV infected patients in Pakistan for the last one and half decade. On average, 2.45% of the patients discontinued treatment due to severe side effects.

CONCLUSION

We encourage further studies on understanding host and viral factors associated with specific focus on harder to treat viral variants (relapsers and nonresponders). These variants are currently rising in the country.

Genetic factors that affect nonalcoholic fatty liver disease: A systematic clinical review

AIM: To investigate roles of genetic polymorphisms in non-alcoholic fatty liver disease (NAFLD) onset, severity, and outcome through systematic literature review.

METHODS: The authors conducted both systematic and specific searches of PubMed through December 2015 with special emphasis on more recent data (from 2012 onward) while still drawing from more historical data for background. We identified several specific genetic polymorphisms that have been most researched and, at this time, appear to have the greatest clinical significance on NAFLD and similar hepatic diseases. These were further investigated to assess their specific effects on disease onset and progression and the mechanisms by which these effects occur.

RESULTS: We focus particularly on genetic polymorphisms of the following genes: PNPLA3, particularly the p. I148M variant, TM6SF2, particularly the p. E167K variant, and on variants in FTO, LIPA, IFNλ4, and iron metabolism, specifically focusing on HFE, and HMOX-1. We discuss the effect of these genetic variations and their resultant protein variants on the onset of fatty liver disease and its severity, including the effect on likelihood of progression to cirrhosis and hepatocellular carcinoma. While our principal focus is on NAFLD, we also discuss briefly effects of some of the variants on development and severity of other hepatic diseases, including hepatitis C and alcoholic liver disease. These results are briefly discussed in terms of clinical application and future potential for personalized medicine.

CONCLUSION: Polymorphisms and genetic factors of several genes contribute to NAFLD and its end results. These genes hold keys to future improvements in diagnosis and management.

Association of IL28B and IL10 gene polymorphism with predisposition to tick-borne encephalitis in a Russian population

Genetic predisposition to tick-borne encephalitis (TBE) is rather poorly studied in human populations. Human genes encoding crucial components of antiviral immune response are most likely involved in protective mechanisms against TBE virus. Previously, several single nucleotide polymorphisms (SNPs) located in interleukin 28B (IL28B) and interleukin 10 (IL10) genes were associated with predisposition to chronic hepatitis C (caused by a structurally similar virus from the same Flaviviridae family) in a number of human populations. The aim of the present study was to estimate a possible association of the IL28B gene rs8103142 and rs12980275 SNPs and IL10 gene rs1800872, rs3021094, and rs3024498 SNPs with predisposition to TBE in a Russian population. Genotypic and allelic frequencies for these SNPs were analyzed in 132 non-immunized TBE patients (34 with fever, 60 with meningitis, and 38 with severe central nervous system disease) and compared with the population control (221 Novosibirsk citizens). The results obtained suggest that both studied IL28B gene SNPs, as well as the IL10 gene rs1800872 SNP are associated with predisposition to TBE in Russian population.

Tumour necrosis factor -308 and -238 promoter polymorphisms are predictors of a null virological response in the treatment of Brazilian hepatitis C patients

Certain host single nucleotide polymorphisms (SNPs) affect the likelihood of a sustained virological response (SVR) to treatment in subjects infected with hepatitis C virus (HCV). SNPs in the promoters of interleukin (IL)-10 (-1082 A/G, rs1800896), myxovirus resistance protein 1 (-123 C/A, rs17000900 and -88 G/T, rs2071430) and tumour necrosis factor (TNF) (-308 G/A, rs1800629 and -238 G/A, rs361525) genes and the outcome of PEGylated α-interferon plus ribavirin therapy were investigated. This analysis was performed in 114 Brazilian, HCV genotype 1-infected patients who had a SVR and in 85 non-responders and 64 relapsers. A significantly increased risk of having a null virological response was observed in patients carrying at least one A allele at positions -308 [odds ratios (OR) = 2.58, 95% confidence intervals (CI) = 1.44-4.63, p = 0.001] or -238 (OR = 7.33, 95% CI = 3.59-14.93, p < 0.001) in the TNF promoter. The risk of relapsing was also elevated (-308: OR = 2.87, 95% CI = 1.51-5.44, p = 0.001; -238: OR = 4.20, 95% CI = 1.93-9.10, p < 0.001). Multiple logistic regression of TNF diplotypes showed that patients with at least two copies of the A allele had an even higher risk of having a null virological response (OR = 16.43, 95% CI = 5.70-47.34, p < 0.001) or relapsing (OR = 6.71, 95% CI = 2.18-20.66, p = 0.001). No statistically significant association was found between the other SNPs under study and anti-HCV therapy response.

Influence of cytokine and cytokine receptor gene polymorphisms on the degree of liver damage in patients with chronic hepatitis C

Hepatic fibrosis may be the result of repetitive injury to hepatocytes caused by HCV infection and the immune response to it. Cytokines regulate the inflammatory response to injury and modulate hepatic fibrogenesis. Single nucleotide polymorphisms (SNPs) located in cytokine genes may influence the cytokine expression and secretion that may contribute to hepatic fibrogenesis in HCV infection. The aim of this study was to determine the genotype of 22 SNPs found in the genes of 13 cytokines/cytokine receptors to assess the influence of polymorphic variants on the stage of liver damage in Brazilian patients chronically infected with HCV genotype 1 only. 141 unrelated patients were grouped according to their stage of fibrosis: absence of fibrosis or patients in the initial stages of fibrosis (F0-F2, n = 84), patients with advanced stages of fibrosis or cirrhosis (F3-F4, n = 57), without cirrhosis (F0-F3, n = 103), and with cirrhosis (F4, n = 38). The comparison of frequencies in each sub-sample was performed by 2 × 2 contingency tables using the chi-square or Fisher's exact test. Stepwise logistic regression was also used to assess independent associations between cirrhosis or fibrosis with polymorphic variants. The TNFA-308G:A genotype conferred increased risk of fibrosis and cirrhosis. The TNFA-238G:G genotype was associated with protection from cirrhosis. The IL10-819C:T genotype conferred protection from fibrosis and the IL1B-511C:T genotype conferred increased risk of cirrhosis. Some of these genotypes showed results on the borderline of statistical significance in the bivariate analysis. We conclude that gene variants of cytokines/receptors may influence liver damage in patients chronically infected by HCV genotype 1.

Responder Interferon λ Genotypes Are Associated With Higher Risk of Liver Fibrosis in HIV-Hepatitis C Virus Coinfection

Background. Liver fibrosis progresses faster in individuals coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). Interferon λ3 (IFN-λ3) has both antiviral and proinflammatory properties. Genotypes at IFNL single-nucleotide proteins (SNPs; rs12979860CC and rs8099917TT) are linked to higher HCV clearance, potentially via rs8103142. We examined the relationship between IFN-λ genotypes and significant liver fibrosis in HIV-HCV coinfection.

Methods. From the prospective Canadian Co-infection Cohort (n = 1423), HCV RNA–positive participants in whom IFN-λ genotypes were detected and who were free of fibrosis, end-stage liver disease, and chronic hepatitis B at baseline (n = 485) were included. Time to significant fibrosis (defined as an aspartate transaminase level to platelet count ratio index [APRI] of ≥1.5) by IFN-λ genotypes was analyzed using Cox proportional hazards, with adjustment for age, sex, ethnicity, alcohol use, CD4⁺ T-cell count, HCV genotype, γ-glutamyl transferase level, and baseline APRI. Haplotype analysis was performed, with adjustment for ethnicity.

Results. A total of 125 participants developed fibrosis over 1595 person-years (7.84 cases/100 person-years; 95% confidence interval [CI], 6.58–9.34 cases/100 person-years). Each genotype was associated with an increased fibrosis risk, with adjusted hazard ratios of 1.37 (95% CI, .94–2.02) for rs12979860CC, 1.34 (95% CI, .91–1.97) for rs8103142TT, and 1.79 (95% CI, 1.24–2.57) for rs8099917TT. Haplotype TCT was also linked with a higher risk (hazard ratio, 1.14 [95% CI, .73–1.77]).

Conclusions. IFN-λ SNPs rs12979860, rs8099917, and rs81013142 were individually linked to higher rates of fibrosis in individuals with HIV-HCV coinfection. IFN-λ genotypes may be useful to target HCV treatments to people who are at higher risk of liver disease.

Potential genetic markers for prediction of treatment response in Egyptian children infected with HCV genotype 4

BACKGROUND

Egypt has a high prevalence of hepatitis C virus (HCV) infection. Limitations of the current HCV treatment in children are low rate of sustained virological response, significant side effects and high expenses, making prediction of treatment response crucial.

AIM

This study aimed to investigate association of single nucleotide polymorphisms (SNPs) in interleukins (IL) 10, 28 and 29 genes in predicting the response to therapy in HCV infected children.

METHODS

Sixty-six Egyptian children infected with HCV genotype 4, receiving pegylated interferon alpha 2b and ribavirin, were included. Genotyping of six SNPs in interleukin 10, 28B and 29 gene as well as HCV genotype were analyzed by real-time polymerase chain reaction.

RESULTS

The CC genotype in IL28B; rs12979860 had 8.547 folds higher chance to develop sustained virological response than CT and TT genotypes (P=0.014). Genotype distribution of rs8099917 in IL28B gene (TG and GG genotypes) was found to be 3.348 more likely not to respond to treatment than the TT genotype (P=0.018). In multivariate analysis, interleukin 28 gene single nucleotide polymorphisms rs 12979860, interleukin 10 single nucleotide polymorphisms -592A > C and basal viral load were independent variables that significantly improved prediction of response to HCV therapy.

CONCLUSION

This association can be translated into clinical decision making for HCV treatment.

Favourable IFNL3 genotypes are associated with spontaneous clearance and are differentially distributed in Aboriginals in Canadian HIV-hepatitis C co-infected individuals

Canadian Aboriginals are reported to clear Hepatitis C (HCV) more frequently. We tested the association of spontaneous clearance and three single nucleotide polymorphisms (SNPs) near the Interferon-lambda 3 (IFNL3) gene (rs12979860, rs8099917, functional variant rs8103142) and compared the SNP frequencies between HIV-HCV co-infected whites and Aboriginals from the Canadian Co-infection Cohort. HCV treatment-naïve individuals with at least two HCV RNA tests were included (n = 538). A spontaneous clearance case was defined as someone with two consecutive HCV RNA-negative tests, at least six months apart. Data were analyzed using Cox proportional hazards adjusted for sex and ethnicity. Advantageous variants and haplotypes were more common in Aboriginals than Caucasians: 57% vs. 46% had the rs12979860 CC genotype, respectively; 58% vs. 48%, rs8103142 TT; 74% vs. 67%, the rs12979860 C allele; and 67% vs. 64% the TCT haplotype with three favourable alleles. The adjusted Hazard Ratios (95% CI) for spontaneous clearance were: rs12979860: 3.80 (2.20, 6.54); rs8099917: 5.14 (2.46, 10.72); and rs8103142: 4.36 (2.49, 7.62). Even after adjusting for rs12979860, Aboriginals and females cleared HCV more often, HR (95% CI) = 1.53 (0.89, 2.61) and 1.42 (0.79, 2.53), respectively. Our results suggest that favourable IFNL3 genotypes are more common among Aboriginals than Caucasians, and may partly explain the higher HCV clearance rates seen among Aboriginals.

Interferon-λ rs12979860 genotype and liver fibrosis in viral and non-viral chronic liver disease

Tissue fibrosis is a core pathologic process that contributes to mortality in ~45% of the population and is likely to be influenced by the host genetic architecture. Here we demonstrate, using liver disease as a model, that a single-nucleotide polymorphism (rs12979860) in the intronic region of interferon-λ4 (IFNL4) is a strong predictor of fibrosis in an aetiology-independent manner. In a cohort of 4,172 patients, including 3,129 with chronic hepatitis C (CHC), 555 with chronic hepatitis B (CHB) and 488 with non-alcoholic fatty liver disease (NAFLD), those with rs12979860CC have greater hepatic inflammation and fibrosis. In CHC, those with rs12979860CC also have greater stage-constant and stage-specific fibrosis progression rates (P<0.0001 for all). The impact of rs12979860 genotypes on fibrosis is maximal in young females, especially those with HCV genotype 3. These findings establish rs12979860 genotype as a strong aetiology-independent predictor of tissue inflammation and fibrosis.

Tissue fibrosis is a major contributor to mortality in the developed world. Here, the authors identify a genetic variant in the intronic region of interferon-λ4 that is a strong predictor of hepatic inflammation and fibrosis, independent of liver disease aetiology

Polymorphisms in melanoma differentiation-associated gene 5 link protein function to clearance of hepatitis C virus

Among patients newly infected with hepatitis C virus (HCV), only 20-30% clear the infection spontaneously. In the remaining 70% the infection persists, causing chronic liver inflammation and disease. It is well established that polymorphisms in host genes, especially in components of the innate immune response, contribute to the phenomenon of spontaneous HCV clearance. Retinoic acid inducible gene-I (RIG-I)-like helicases such as melanoma differentiation-associated gene 5 (MDA-5) are cytoplasmic sensors of viral RNA that are critical for triggering innate immune responses after infection with RNA viruses. We analyzed 14 nonsynonymous single-nucleotide polymorphisms in RIG-I-like helicase-pathway-genes comparing European patients who spontaneously cleared HCV (n = 285) or had persistent infection (n = 509). We found that polymorphic haplotypes in the MDA-5 gene IFIH1 encoding histidine at position 843 and threonine at position 946 strongly correlate with the resolution of HCV infection (odds ratio [OR]: 16.23; 95% confidence interval [CI]: 3.67-71.87; P = 1.1 × 10(-6) ). Overexpression of MDA-5 genetic variants in HEK 293 cells and in a tissue culture model of HCV infection revealed that the histidine 843/threonine 946 variant leads to increased baseline and ligand-induced expression of interferon-induced genes and confers an increased ability to suppress HCV replication.

CONCLUSION

These data suggest that MDA-5 plays a significant role in the defense against HCV and that polymorphisms in MDA-5 can influence the outcome of HCV infection.

A systematic appraisal of field synopses in genetic epidemiology: a HuGE review

Evidence from genetic association studies is accumulating rapidly. Field synopses have recently arisen as an unbiased way of systematically synthesizing this evidence. We performed a systematic review and appraisal of published field synopses in genetic epidemiology and assessed their main findings and methodological characteristics. We identified 61 eligible field synopses, published between January 1, 2007, and October 31, 2013, on 52 outcomes reporting 734 significant associations at the P < 0.05 level. The median odds ratio for these associations was 1.25 (interquartile range, 1.15-1.43). Egger's test was the most common method (n = 30 synopses) of assessing publication bias. Only 12 synopses (20%) used the Venice criteria to evaluate the epidemiologic credibility of their findings (n = 449 variants). Eleven synopses (18%) were accompanied by an online database that has been regularly updated. These synopses received more citations (P = 0.01) and needed a larger research team (P = 0.02) than synopses without an online database. Overall, field synopses are becoming a valuable tool for the identification of common genetic variants, especially when researchers follow relevant methodological guidelines. Our work provides a summary of the current status of the field synopses published to date and may help interested readers efficiently identify the online resources containing the relevant genetic evidence.

Association between polymorphisms in OAS2 and CD209 genes and predisposition to chronic hepatitis C in Russian population

Chronic hepatitis C is a severe liver disease caused by positive-strand RNA virus. Previously, we reported an association between seven single nucleotide polymorphisms (SNPs) in four innate immunity genes (OAS2, OAS3, CD209, and TLR3) and human predisposition to tick-borne encephalitis, caused by a virus from the same Flaviviridae family, in a Russian population. Currently, genotype and allele frequencies for these SNPs were analyzed in 75 chronic hepatitis C patients and compared with the population control (269 Novosibirsk citizens). Data obtained suggest that the OAS2 rs1293762 and CD209 rs2287886 SNPs are associated with predisposition to chronic hepatitis C in Russian population.

Association of IL28B polymorphism with fibrosis, liver inflammation, gender respective natural history of hepatitis C virus in Egyptian patients with genotype 4

The polymorphism of interleukin 28B (IL28B) rs12979860 is associated with spontaneous and treatment-induced clearance in hepatitis C virus (HCV) genotype 4 (G4). However, there is no information on its interaction with gender, moreover its association with intrahepatic inflammation in North Africans is not studied and its association with fibrosis in North Africans (especially Egyptians) is controversial. This study aims to explore the association between the minor allele of the IL28B rs12979860 polymorphism with gender, fibrosis and necroinflammation in Egyptian G4 HCV patients. IL28B rs12979860 was genotyped in 224 individuals, including 100 healthy controls and 124 consecutive patients with chronic HCV. Results showed (1) IL28B rs12979860 minor alleles associated with susceptibity to chronic HCV mainly in men not women, (2) no association between IL28B rs12979860 with fibrosis and necroinflammation activity, (3) the IL28B rs12979860 TT genotype associated with severe fibrosis in women only and with the necroinflammation activity in men using a recessive model. In conclusion, the IL28B rs12979860 polymorphism is not associated with fibrosis and liver inflammation in Egyptian HCV G4. Nonetheless, the TT genotype of IL28B rs12979860 polymorphism affects the natural history of each gender independently.

Association between vitamin D and hepatitis C virus infection: A meta-analysis

AIM: To evaluate the association between 25-hydroxyvitamin D [25(OH)D] and sustained virological response (SVR) in hepatitis C virus (HCV) infected individuals.

METHODS: Relevant studies were identified by systematically searching MEDLINE databases up to March 2012 and abstracts of the European and American Congress of Hepatology conducted in 2011. Studies must provide information on SVR and the levels of 25(OH)D₃ and/or 25(OH)D₂ [henceforth referred to as 25(OH)D] in sera samples from HCV infected individuals. The inclusion criteria were: clinical studies that included HCV infected patients aged older than 18 years regardless of HCV genotype or ethnic group; provided information on SVR rates; and were reported in the English language as full papers. Due to the heterogeneity of studies in categorizing serum vitamin D levels, a cut-off value of 30 ng/mL of serum 25(OH)D was used. Heterogeneity was assessed using I² statistics. The summary odds ratios with their corresponding 95%CI were calculated based on a random-effects model.

RESULTS: Overall, 11 studies (8 observational and 3 interventional) involving 1575 individuals were included and 1117 HCV infected individuals (71%) showed low vitamin D levels. Most of the studies included mono-infected HCV individuals with the mean age ranging from 38 to 56 years. Four studies were conducted in human immunodeficiency virus/HCV infected individuals. Regarding vitamin D measurement, most of the studies employed radioimmunoassays (n = 5) followed by chemiluminescence (n = 4) and just one study employed high performance/pressure liquid chromatography (HPLC). Basal vitamin D levels varied from 17 to 43 ng/mL in the studies selected, and most of the HCV infected individuals had genotype 1 (1068/1575) with mean viral load varying from log 4.5-5.9 UI/mL. With regard to HCV treatment, most of the studies (n = 8) included HCV individuals without previous treatment, where the pooled SVR rate was 46.4%. High rates of SVR were observed in HCV individuals with vitamin D levels above 30 ng/mL (OR = 1.57; 95%CI: 1.12-2.2) and those supplemented with vitamin D (OR = 4.59; 95%CI: 1.67-12.63) regardless of genotype.

CONCLUSION: Our results demonstrated high prevalence of vitamin D deficiency and high SVR in individuals with higher serum vitamin D levels or receiving vitamin D supplementation.

A combined proteomics and computational approach provides a better understanding of HCV-induced liver disease

HCV is a major cause of chronic liver disease worldwide and is a formidable therapeutic challenge. Recently, Diamond et al. analyzed the proteomic profiles of liver samples from HCV-positive liver transplant recipients, supplemented with an independent metabolite analysis. They used a computational approach, which highlighted the enriched functional themes and topological attributes associated with the protein association network based on their clinical data and suggested a crucial role of oxidative stress in fibrosis progression in HCV infection. Their findings provide new insights into the mechanisms that regulate the progression of HCV-associated liver fibrosis, which may be useful for identification of suitable biomarkers to evaluate the onset and severity of hepatic fibrosis and the development of new therapeutic and anti-HCV strategies.

Challenges in the treatment of chronic hepatitis C in the HIV/HCV-coinfected patient

Hepatitis C virus (HCV) and HIV are common coinfections that convey a shortened lifespan, mostly related to liver disease. Treatment against HCV in the coinfected patient is notoriously more complex and challenging. There are no optimal treatment algorithms for HIV/HCV coinfected patients as efficacy of approved anti-HCV therapies is low with relevant side effects. The use of direct-acting antivirals for anti-HCV therapy has the potential to improve therapeutic efficacy, but also increase side effects and drug-drug interactions. In spite of all of this, the most important and significant fact is that chronic hepatitis C is potentially curable, and the eradication of the HCV infection is a crucial outcome in this population. The establishment of a productive collaboration among the regulatory agencies, the medical community and the pharmaceutical industry could lead to faster access to more effective HCV therapies for the coinfected patient and eventually stop the progression of liver disease in these 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.

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.

Interleukin-28B polymorphisms on the SVR in the treatment of naïve chronic hepatitis C with pegylated interferon-α plus ribavirin: a meta-analysis

There are accurate but inconclusive data on the association between single nucleotide polymorphisms (SNPs) of interleukin (IL)-28B and sustained virological response (SVR) in chronic hepatitis C (CHC). This meta-analysis aimed to derive a more precise estimation of the effects of IL-28B SNPs locus (rs12979860 and rs8099917) on SVR in naïve CHC patients receiving pegylated interferon alpha (PEG-IFN-α) plus ribavirin. Literature search was conducted up to June, 2011, in PubMed, EMBASE and Cochrane Database of Systematic Reviews. A total of 36 studies involving 10912 cases with CHC receiving PEG-IFN-α plus ribavirin met the inclusion criteria. Analyses were stratified either by ethnicity or genotype of hepatitis C virus. In genotype 1/4 patients, rs12979860 CC was associated with high SVR in CHC patients (Caucasian: odds ratio (OR), 4.567; 95% confidence interval (CI), 3.826-5.452; Asian: OR, 4.033; 95%CI, 3.050-5.333; African American: OR, 4.297; 95%CI, 2.168-8.515; Hispanics: OR, 4.350; 95%CI, 2.817-6.717) but had no effect in genotype 2/3. In Caucasian (genotype 1/4: OR, 2.542; 95%CI, 2.108-3.065; genotype 2/3: OR, 1.363; 95%CI, 1.020-1.820) and Asian (genotype 1/4: OR, 5.214; 95%CI, 3.694-7.360; genotype 2/3: OR, 1.785; 95%CI, 1.095-2.910), rs8099917 TT was associated with high SVR in both genotype 1/4 and 2/3. Meta-regression showed that in Caucasians with CHC genotype 1/4, gender male might contribute to the effect of rs12979860 on SVR but advanced fibrosis might weaken this effect. Furthermore, in Asians with CHC genotype 1/4, high baseline viral load and advanced fibrosis might also undermine the effect of rs8099917 on SVR. This meta-analysis suggested that IL-28B rs12979860 CC and rs8099917 TT were associated with high SVR rate in CHC genotype 1/4. In CHC genotype 2/3, rs8099917 TT carriers also had higher SVR.

IL28B polymorphism as a predictor of antiviral response in chronic hepatitis C

AIM

To evaluate the effect of single nucleotide polymorphisms of interleukin (IL)-28B, rs12979860 on progression and treatment response in chronic hepatitis C.

METHODS

Patients (n = 64; 37 men, 27 women; mean age, 44 ± 12 years) with chronic hepatitis C, genotype 1, received treatment with peg-interferon plus ribavirin. Genotyping of rs12979860 was performed on peripheral blood DNA. Histopathological assessment of necroinflammatory grade and fibrosis stage were scored using the METAVIR system on a liver biopsy sample before treatment. Serum viral load, aminotransferase activity, and insulin level were measured. Insulin resistance index, body mass index, waist/hip ratio, percentage of body fat and fibrosis progression rate were calculated. Applied dose of interferon and ribavirin, platelet and neutrophil count and hemoglobin level were measured.

RESULTS

A sustained virological response (SVR) was significantly associated with IL28B polymorphism (CC vs TT allele: odds ratio (OR), 25; CC vs CT allele: OR, 5.4), inflammation activity (G < 1 vs G > 1: OR, 3.9), fibrosis (F < 1 vs F > 1: OR, 5.9), platelet count (> 200 × 10(9)/L vs < 200 × 10(9)/L: OR, 4.7; OR in patients with genotype CT: 12.8), fatty liver (absence vs presence of steatosis: OR, 4.8), insulin resistance index (< 2.5 vs > 2.5: OR, 3.9), and baseline HCV viral load (< 10(6) IU/mL vs > 10(6) IU/mL: OR, 3.0). There was no association with age, sex, aminotransferases activity, body mass index, waist/hip ratio, or percentage body fat. There was borderline significance (P = 0.064) of increased fibrosis in patients with the TT allele, and no differences in the insulin resistance index between groups of patients with CC, CT and TT alleles (P = 0.12). Spearman's rank correlation coefficient between insulin resistance and stage of fibrosis and body mass index was r = 0.618 and r = 0.605, respectively (P < 0.001). Significant differences were found in the insulin resistance index (P = 0.01) between patients with and without steatosis. Patients with the CT allele and absence of a SVR had a higher incidence of requiring threshold dose reduction of interferon (P = 0.07).

CONCLUSION

IL28B variation is the strongest host factor not related to insulin resistance that determines outcome of antiviral therapy. Baseline platelet count predicts the outcome of antiviral therapy in CT allele patients.

The H63D mutation of the hemochromatosis gene is associated with sustained virological response in chronic hepatitis C patients treated with interferon-based therapy: a meta-analysis

The hemochromatosis (HFE) gene encodes the HFE protein that regulates iron absorption. HFE mutations lead to the hemochromatosis disease of excessive iron absorption. HFE mutations may also influence the sustained virologic response (SVR, long-term virus suppression) in chronic hepatitis C patients treated with interferon-based antiviral therapy. We performed a meta-analysis of all English and Chinese language studies of HFE mutations and SVR in interferon-treated chronic hepatitis C patients indexed in the Medline, PubMed, Embase, and China National Knowledge Infrastructure databases to November 2011. Seven studies involving 605 patients with HFE mutations (homozygous or heterozygous mutation of C282Y, H63D or S65C) and 1279 with wild-type HFE (no mutation of C282Y, H63D or S65C for both alleles) were analyzed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated with the fixed- or random-effect models. HFE mutations were associated with significantly higher SVR rate (vs. wild-type: OR = 1.56, 95% CI: 1.23-1.97, P < 0.001), indicating that mutation carriers were likely to achieve SVR in response to interferon-based antiviral therapy. Stratification analysis by HFE mutation type revealed that the H63D mutation was associated with a significantly higher SVR rate (OR = 1.60, 95% CI: 1.09-2.34, P = 0.020), while the C282Y mutation was not (OR = 1.19, 95% CI: 0.71-1.98, P = 0.510). Our meta-analysis results indicate that the H63D mutation in HFE is associated with a higher SVR rate in chronic hepatitis C patients treated with interferon-based antiviral therapy.

Early transcriptional programming links progression to hepatitis C virus-induced severe liver disease in transplant patients

Liver failure resulting from chronic hepatitis C virus (HCV) infection is a major cause for liver transplantation worldwide. Recurrent infection of the graft is universal in HCV patients after transplant and results in a rapid progression to severe fibrosis and end-stage liver disease in one third of all patients. No single clinical variable, or combination thereof, has, so far, proven accurate in identifying patients at risk of hepatic decompensation in the transplant setting. A combination of longitudinal, dimensionality reduction and categorical analysis of the transcriptome from 111 liver biopsy specimens taken from 57 HCV-infected patients over time identified a molecular signature of gene expression of patients at risk of developing severe fibrosis. Significantly, alterations in gene expression occur before histologic evidence of liver disease progression, suggesting that events that occur during the acute phase of infection influence patient outcome. Additionally, a common precursor state for different severe clinical outcomes was identified.

CONCLUSION

Based on this patient cohort, incidence of severe liver disease is a process initiated early during HCV infection of the donor organ. The probable cellular network at the basis of the initial transition to severe liver disease was identified and characterized.

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.

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.

The impact of genetic variability on liver disease in the Hispanic/Latin-American population

Liver cirrhosis is within the top 10 causes of death in Latin-American countries and recent evidence suggests that Hispanics in the USA have a more aggressive course of many types of liver disease and show lower response to treatment of hepatitis C compared with other ethnic groups. Although environmental factors are very important, they do not appear to fully account for the observed ethnic differences in the incidence of cirrhosis and progression rates. Genome-wide association studies have been a powerful tool to identify genetic variants that directly confer susceptibility to liver disease. Here, we review the current knowledge on genetic variants associated with the most common types of liver disease that may contribute to ancestry-related differences in disease progression and mortality.

Interleukin 28B Polymorphisms and Hepatitis C-Translating the Association into Clinical Decision Making

Host genetic factors have long been suspected to play a role in predicting outcome and treatment response in hepatitis C virus (HCV) infection. This was confirmed recently by three landmark genome-wide association studies (GWAS) published in 2009, which identified single nucleotide polymorphisms near the interleukin (IL) 28B region that were more common in responders to treatment. There has subsequently been rapidly increasing data regarding the significance of the IL28B polymorphism not only in response to therapy but also in spontaneous clearance of acute HCV infection. This clinical association of Il28B genotype with HCV may lead to personalized HCV therapy, where the clinician may tailor the duration and type of therapy for an individual patient. This review summarizes the available data on the impact of IL28B polymorphisms on HCV infection and discusses the possible approach to translate this association into clinical decision making for the treatment of HCV infection.