Cytokine gene polymorphisms in patients infected with hepatitis B virus

Interferon-γ and Tumor Necrosis Factor-α Produced by T Cells Reduce the HBV Persistence Form, cccDNA, Without Cytolysis

BACKGROUND & AIMS

Viral clearance involves immune cell cytolysis of infected cells. However, studies of hepatitis B virus (HBV) infection in chimpanzees have indicated that cytokines released by T cells also can promote viral clearance via noncytolytic processes. We investigated the noncytolytic mechanisms by which T cells eliminate HBV from infected hepatocytes.

METHODS

We performed a cytokine enzyme-linked immunosorbent assay of serum samples from patients with acute and chronic hepatitis B. Liver biopsy specimens were analyzed by in situ hybridization. HepG2-H1.3 cells, HBV-infected HepaRG cells, and primary human hepatocytes were incubated with interferon-γ (IFNγ) or tumor necrosis factor-α (TNF-α), or co-cultured with T cells. We measured markers of HBV replication, including the covalently closed circular DNA (cccDNA).

RESULTS

Levels of IFNγ and TNF-α were increased in serum samples from patients with acute vs chronic hepatitis B and controls. In human hepatocytes with stably replicating HBV, as well as in HBV-infected primary human hepatocytes or HepaRG cells, IFNγ and TNF-α each induced deamination of cccDNA and interfered with its stability; their effects were additive. HBV-specific T cells, through secretion of IFNγ and TNF-α, inhibited HBV replication and reduced cccDNA in infected cells without the direct contact required for cytolysis. Blocking IFNγ and TNF-α after T-cell stimulation prevented the loss of cccDNA. Deprivation of cccDNA required activation of nuclear APOBEC3 deaminases by the cytokines. In liver biopsy specimens from patients with acute hepatitis B, but not chronic hepatitis B or controls, hepatocytes expressed APOBEC3A and APOBEC3B.

CONCLUSIONS

IFNγ and TNF-α, produced by T cells, reduce levels of HBV cccDNA in hepatocytes by inducing deamination and subsequent cccDNA decay.

The association of TNF-308 (G/A) gene polymorphisms and hepatocellular carcinoma risk: a meta-analysis

Objective

Many studies have examined the association between the TNF-308 G/A polymorphism gene polymorphisms and hepatocellular carcinoma risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed.

Methods

The PubMed and CNKI (China National Knowledge Infrastructure) database was searched for case-control studies. Odds ratios (OR) with 95% CIs were used to determine the strength of association between the TNF-308 G/A polymorphisms and HCC risk. The pooled ORs for the risk associated with the TNF-308 G/A genotype, the A carriers (A/G + A/A) vs. the wild-type homozygotes (G/G), A/A vs. G/G were calculated, respectively. Subgroup analyses were done by ethnicity and smoking status. Heterogeneity assumptions were assessed by chi-square-based Q-test.

Results

Ultimately, 21 studies, comprising 2,923 hepatocellular carcinoma cases and 4,323 controls were included. Overall, the A carriers (G/A + A/A) vs. the wild-type homozygotes (G/G), the pooled OR was 1.05 (95% CI, 0.93-1.19; P=0.000 for heterogeneity), for A/A vs. G/G the pooled OR was 1.07 (95% CI, 0.95-1.21; P=0.007 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among non-Asians. However, for Asians, significantly risks were not found.

Conclusions

The TNF-308 G/A polymorphisms are not associated with hepatocellular carcinoma risk among Asians, but for non-Asians.

Quantitative assessment of common genetic variations in HLA-DP with hepatitis B virus infection, clearance and hepatocellular carcinoma development

Hepatitis B virus (HBV) infection is the predominant risk factor for chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Recently, genome-wide association studies have identified human leukocyte antigen (HLA)-DP polymorphisms (rs3077 and rs9277535) as a new chronic HBV infection susceptibility locus. Since then, the relationship between HLA-DP polymorphisms and various outcomes of HBV infection has been reported. However, the results have been inconclusive. To derive a more precise estimation of the relationship between HLA-DP polymorphisms and various outcomes of HBV infection, a meta-analysis of 62,050 subjects from 29 case-control studies was performed. We found that rs3077 and rs9277535 in HLA-DP significantly decreased HBV infection risks and increased HBV clearance possibility in a dose-dependent manner. In the subgroup analysis by ethnicity, study design and sample size, significant associations were found for these polymorphisms in almost all comparisons. Meanwhile, haplotype analyses of the two polymorphisms revealed a significant association between the combination of these alleles and HBV infection outcomes. However, no significant results were observed in HCC development. Our results further confirm that genetic variants in the HLA-DP locus are strongly associated with reduced HBV infection and increased the likelihood of spontaneous viral clearance.

IL6 gene allele-specific C/EBPα-binding activity affects the development of HBV infection through modulation of Th17/Treg balance

Interleukin-6 (IL-6) has an important role in the pathogenesis of chronic viral hepatitis and related liver diseases. Although host genetics associated with the response to anti-viral treatment have been reported, little is known about the relationship between IL6 genetic polymorphisms and the outcome of hepatitis B virus (HBV) infection. In this study, we determined the genotype distribution of rs1800796 polymorphism in healthy controls and cases including chronic HBV (CHB), hepatitis C virus and HIV infection. The rs1800796 was found to be associated with clinical outcome of CHB in experimental and validation cohort. The rs1800796C allele has twofold higher promoter activity than G allele. Consistently, CD14(+) monocytes from subjects carrying the rs1800796C allele produced more IL-6 in response to in vitro HBV core antigen stimulation than those carrying G allele. Moreover, CHB patients carrying rs1800796C allele have significantly higher T-helper 17 (Th17) and regulatory T cell (Treg) ratio. Finally, a transcription factor C/EBPα binds in higher affinity to rs1800796C allele than to G allele. These results suggest that genetic predisposition to higher IL-6 production is associated with increased risk to HBV infection and hepatic inflammation, which might be due to C/EBPα-mediated regulatory effect on Th17 and Treg responses. Appropriate manipulation of IL-6 expression might be used to prevent and treat HBV infection.

Impact of the IL-10 Promoter Gene Polymorphisms in the Severity of Chronic Hepatitis B Infection

BACKGROUND

Interleukin-10 (IL-10) is an important anti-inflammatory cytokine. The polymorphisms of its promoter gene have been considered to be related with the chronicity of hepatitis B infection.

OBJECTIVES

The aim of this study was to evaluate the polymorphisms at different positions in the IL-10 promoter gene in patients with chronic hepatitis B.

PATIENTS AND METHODS

Totally, 166 patients with chronic hepatitis B infection were enrolled. Genotypes at different positions (i.e. -819, - 592, and - 1082) in the IL-10 gene promoter were determined.

RESULTS

The C/A genotype at position -592, C/T genotype at position -819, and GCC/ATA haplotype of the IL-10 gene promoter were significantly more common in the patients with cirrhosis. The genotypes were significantly different between the hepatitis B e antigen (HBeAg)-negative and HBeAg-positive patients at position -592 (C/A and C/C), position -819 (C/C and C/T), and position -1082 (A/A and G/A).

CONCLUSIONS

Some IL-10 promoter gene polymorphisms predisposed the infected hepatitis B virus cases to cirrhosis in our study population.

The relationship between TNF alpha gene polymorphisms (-238/-308), TNF RII VNTR (p75) and outcomes of hepatitis B virus infection in Tunisian population

The present study was undertaken to investigate the association between Hepatitis B Virus (HBV) infection and polymorphisms of tumour necrosis factor alpha TNF-α -308 G>A, TNF-α -238 G>A and TNF RII VNTR (p75) gene promoter in a Tunisian population. Blood samples were collected from 100 Tunisian patients with HBV infection, 45 with Chronic Hepatitis (CH), 36 with Liver Cirrhosis (LC), 15 with Hepatocellular Carcinoma (HCC) and 200 healthy individuals of similar ethnicity. Genomic DNA was extracted from peripheral blood leukocytes. Genotyping of the analysed polymorphisms was performed using Amplified Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR), Restriction Fragment Length Polymorphism (RFLP) and Variable Number Tandem Repeat PCR (PCR-VNTR). The variant homozygotes -308 GG were associated with 50% decreased risk of HBV chronic infection (GG vs AA+GA; p=0.010; OR=0.50; 95%CI=0.29-0.85). However, the carriers of minor allele -308 A have higher risk (1.5 times) to develop a chronic infection than other patients (p=0.027; OR=1.46; 95%CI=1.04-2.06). The minor allele of -238 polymorphism was positively associated with virus resistance and the development of chronic infection (p=0.043; OR=1.42; 95%CI =1.01 1.99). The distribution of -308, -238 and TNF RII VNTR (p75) among the three groups differed significantly. For HCC groups, there were statistically significant differences in allele distribution in -308, -238 respectively in which A allele remains a risk factor for HBV evolution to HCC (p=0.008 and p=0.026). Haplotype analysis revealed that TNF-α (-308A; -238A) was significantly associated to HBV chronic infection and moreover to disease aggravation to HCC stage. Our findings imply that variations in the genes governing the levels of constitutive and inducible TNF-α and TNF RII might be an important risk factor, which could explain the variable outcomes of HBV infection.

IL-18, TNF, and IFN-γ alleles and genotypes are associated with susceptibility to chronic hepatitis B infection and severity of liver injury

This study evaluated the association of polymorphisms in the IL-18 (-607C/A and -137C/G), IFNγ (+874 A/T), and TNF (-238 A/G and -308 A/G) genes with susceptibility to HBV infection and severity of liver injury. A total of 259 chronic HBV-infected patients followed at the University Hospital, Faculty of Medicine of Ribeirão Preto, São Paulo, Brazil, and 202 healthy individuals were studied. Four Single Nucleotide Polymorphisms (SNPs) were amplified by Polymerase Chain Reaction (PCR). Liver biopsy was performed in 212 HBV-infected patients and classified according to severity of liver fibrosis (scores 0-4) and necroinflammatory activity (HAI scores 0-18). TNF-308*A allele (P < 0.001; OR = 2.16) and TNF -308 AA genotype (P = 0.026; OR = 5.43) were associated with susceptibility to HBV infection. An association was found between severe liver fibrosis when compared to mild fibrosis and the following polymorphisms: Alleles IL-18 -137*G (P = 0.004; OR = 3.45), TNF -308*A (P < 0.001; OR = 3.39), and IFNγ +874*T (P = 0.029; OR = 1.85) and IL-18 -137 GG genotype (P = 0.009; OR = 3.70). No significant association was found between IL-18 (-607 A/C) polymorphism and severity of liver fibrosis. Alleles IL-18 -137*G (P = 0.028; OR = 2.64) and TNF-308*A (P = 0.002; OR = 3.06) and IL-18 -137 GG genotype (P = 0.011; OR = 4.20) were associated with severe necroinflammatory activity (HAI>12) when compared to mild necroinflammatory activity (HAI 1-8). The results suggest that IL-18 -137C/G, TNF-308 G/A and IFNγ +874 A/T SNPs were associated to more severe liver injury in chronic HBV infection. TNF -308*A allele and TNF -308 AA genotype could play a role in the susceptibility to HBV infection.

Interferon Gamma +874T/A Polymorphism Increases the Risk of Hepatitis Virus-Related Diseases: Evidence from a Meta-Analysis

Background

Interferon gamma (IFN-γ) is a key regulatory cytokine, which plays an important role in antiviral defense of an infected host. However, the association between the IFN-γ +874T/A gene polymorphism and hepatitis virus-related diseases is heterogeneous.

Methods

Based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement, a comprehensive literature search of eligible studies in Embase, Pubmed, and the Cochrane Library was undertaken through November 2014. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were used to measure the strength of the models.

Results

Seventeen case-control articles, including 24 studies with 5503 individuals, met the inclusion criteria. The results indicated a statistically significant association between the IFN-γ +874T/A polymorphism and hepatitis virus—related diseases in a recessive gene model (AA vs. TT+TA: OR=1.350, 95% CI=1.101-1.657, P=0.004, I²%=54.3, and P_Q=0.001 for heterogeneity), especially in Asians (OR=1.407, 95% CI=1.035-1.911, P=0.029, I²%=61.9, and P_Q=0.005 for heterogeneity) and hepatitis B virus (HBV)–related disease (OR=1.486, 95% CI=1.195–1.849, P=0.000, I²%=40.4, and P_Q=0.053 for heterogeneity).

Conclusions

The evidence suggests that the IFN-γ +874T/A polymorphism increases the risk of hepatitis virus—related diseases, especially in Asians and HBV—related diseases. Further studies on this topic in different ethnicities, especially genome-wide association studies, should be conducted to strengthen our results.

Neonatal infections in Saudi Arabia: Association with cytokine gene polymorphisms

In recent years, many studies have reported potential associations between cytokine gene polymorphisms and the development, course, and outcome of sepsis, often with apparently conflicting results. The objective of this study was to investigate single nucleotide polymorphism (SNP) in the interleukin (IL)-1β –31 T/C, IL-6 –174 G/C, tumor necrosis factor α (TNF-α) –308 G/A, and interferon γ (IFN-γ) +874 A/T genes for their possible association with susceptibility to early onset sepsis (EOS) in Saudi newborn infants. A total of 205 newborn infants aged 1-2 days were consecutively enrolled onto the study having met the inclusion criteria (as per the research protocol). DNA was extracted from filter papers using the Chelex-100 method. The cytokines SNP were genotyping using Taqman 5’ nuclease allelic discrimination. For cytokine measurements we used the commercially available Enzyme-Linked Immunosorbent Assay (ELISA) kit. Our results show that the circulating IL-1β, IL-6, TNF-α, and IFN-γ were significantly (p < 0.001) elevated in EOS patients compared to suspected and sepsis-free control groups; and IL-1β –31C, IL-6 –174G, TNF-α –308G, and IFN-γ +874A alleles were associated with EOS in Saudi infants. In conclusion, analysis of cytokines concentrations and SNP for the four tested genes can be used as a predictor of sepsis outcome in newborns.

Interferon gamma polymorphisms and hepatitis B virus-related liver cirrhosis risk in a Chinese population

Background

Previous studies proved that interferon gamma (IFN-γ) gene polymorphisms were associated with the risk of hepatitis B virus (HBV) infection. However, the association between IFN-γ polymorphisms and HBV-related liver cirrhosis (HBV-LC) risk is still unclear.

Methods

IFN-γ +874 T/A and +2109G/A genotypes were determined in 126 HBV-LC patients, 129 chronic hepatitis B(CHB) patients, and 173 early HBV infection controls using a sequence-specific primer-polymerase chain reaction and a polymerase chain reaction-restriction fragment length polymorphism, respectively.

Results

Significant associations were observed between +2109A/G polymorphisms and HBV-LC risk in the co-dominant model (GG vs. AA: OR = 0.321, 95% CI = 0.130-0.793, P = 0.014), the allelic model (OR = 0.565, 95% CI = 0.388-0.825, P = 0.003), the dominant model (OR = 0.551, 95% CI = 0.344-0.883, P = 0.013), and the recessive model (OR = 0.385, 95% CI = 0.159-0.930, P = 0.034). In addition, haplotype analysis indicated that the T⁺⁸⁷⁴G⁺²¹⁰⁹ haplotype significantly decreased the HBV-LC risk (OR = 0.106, 95% CI = 0.022-0.502, P = 0.000), and A⁺⁸⁷⁴A⁺²¹⁰⁹ haplotype significantly increased the LC risk (OR = 1.485, 95% CI = 1.065-2.070, P = 0.019). No significant associations were observed between IFN-γ +874 T/A polymorphisms and HBV-LC risk, as well as the two single-nucleotide polymorphisms (SNPs) and CHB risk (P > 0.05).

Conclusions

Our observations suggested a significant association of IFN-γ polymorphisms with HBV-LC risk in the Chinese population.

Age-related immune clearance of hepatitis B virus infection requires the establishment of gut microbiota

A unique feature of hepatitis B virus (HBV) infection in humans is that viral clearance heavily depends on the age of exposure. However, the reason for this remains unclear. Here we show that gut microbiota contribute to the age dependence of HBV immunity in a hydrodynamic transfection mouse model. Although adult (12-wk-old) C3H/HeN mice cleared HBV within 6 wk postinjection (wpi), their young (6-wk-old) counterparts remained HBV-positive at 26 wpi. Sterilization of gut microbiota from 6 to 12 wk of age using antibiotics prevented adult mice from rapidly clearing HBV. Young mice with the Toll-like-receptor (TLR) 4 mutation (C3H/HeJ) exhibited rapid HBV clearance. The results suggest that an immuno-tolerating pathway to HBV prevailed in young mice, before the establishment of gut bacteria, through a TLR4-dependent pathway and that the maturation of gut microbiota in adult mice stimulated liver immunity, resulting in rapid HBV clearance.

Association between IL-10 gene promoter polymorphism and hepatitis B viral infection in an Egyptian population

Cytokines play critical roles in the pathogenesis of hepatitis B virus infection (HBV). This work was designed to study the effect of IL-10 gene polymorphisms (-1082G/A and -819C/T) on susceptibility of Egyptians to HBV. Genotyping was performed using single-stranded polymorphism-polymerase chain reaction in 118 Egyptian hepatitis B patients and 119 healthy controls, and IL-10 serum levels were measured using ELISA. The frequency of IL-10 -1082G/G was significantly higher in HBV patients than in healthy controls, and G/A and A/A were not significantly different between groups. The distribution of IL-10 -819 genotypes was not significantly different between the HBV and healthy control groups. Although AT was significantly different between controls and patients, the distribution of the other haplotypes was not. IL-10 levels were significantly lower among hepatitis B patients. Our data stress the importance of IL-10 gene polymorphism in HBV infection. Depending on our preliminary work, IL-10 -1082G/G may act as a host genetic factor in the susceptibility to HBV infection in Egyptians.

Tumor necrosis factor-alpha induced by hepatitis B virus core mediating the immune response for hepatitis B viral clearance in mice model

Persistent hepatitis B viral (HBV) infection results in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma (HCC). An efficient control of virus infections requires the coordinated actions of both innate and adaptive immune responses. In order to define the role of innate immunity effectors against HBV, viral clearance was studied in a panel of immunodeficient mouse strains by the hydrodynamic injection approach. Our results demonstrate that HBV viral clearance is not changed in IFN-α/β receptor (IFNAR), RIG-I, MDA5, MYD88, NLRP3, ASC, and IL-1R knock-out mice, indicating that these innate immunity effectors are not required for HBV clearance. In contrast, HBV persists in the absence of tumor necrosis factor-alpha (TNF-α) or in mice treated with the soluble TNF receptor blocker, Etanercept. In these mice, there was an increase in PD-1-expressing CD8⁺ T-cells and an increase of serum HBV DNA, HBV core, and surface antigen expression as well as viral replication within the liver. Furthermore, the induction of TNF-α in clearing HBV is dependent on the HBV core, and TNF blockage eliminated HBV core-induced viral clearance effects. Finally, the intra-hepatic leukocytes (IHLs), but not the hepatocytes, are the cell source responsible for TNF-α production induced by HBcAg. These results provide evidences for TNF-α mediated innate immune mechanisms in HBV clearance and explain the mechanism of HBV reactivation during therapy with TNF blockage agents.

HLA-DQ polymorphisms with HBV infection: different outcomes upon infection and prognosis to lamivudine therapy

Two recent genome-wide studies showed that the single-nucleotide polymorphisms in the HLA-DQ region (rs2856718 and rs9275572) were associated with chronic hepatitis B virus infection and chronic hepatitis C virus-associated hepatocellular carcinoma in Japanese patients. We tested the effects of the two single-nucleotide polymorphisms for all major HBV outcomes and lamivudine treatment in Han Chinese. A total of 1649 samples were enrolled, and peripheral blood samples were collected in this study. The single-nucleotide polymorphisms in the HLA-DQ region were genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Our study demonstrated the clear relevance of HLA-DQ rs2856718 and rs9275572 with HBV susceptibility, natural clearance and HBV-associated HCC. HLA-DQ rs2856718G and rs9275572A were strongly associated with decreased risk of chronic HBV infection (odds ratio = 0.641; P = 2.64 × 10(-4) ; odds ratio = 0.627, P = 7.22 × 10(-5) ) and HBV natural clearance (odds ratio = 0.610; P = 4.80 × 10(-4) ; odds ratio = 0.714, P = 0.013). Moreover, rs9275572A was also associated with development of cirrhosis and hepatocellular carcinoma (odds ratio = 0.632, P = 0.008). In addition, we showed for the first time to our knowledge that rs9275572 was a predictor for lamivudine therapy (viral response: odds ratio = 2.599, P = 4.43 × 10(-4) ; biochemical response: odds ratio = 2.279, P = 4.23 × 10(-4) ). Our study suggested that HLA-DQ loci were associated with both HBV clearance and HBV-related diseases and outcomes of lamivudine treatment in Han Chinese.

Relationship between cytokine gene polymorphisms and chronic hepatitis B virus infection

Hepatitis B virus (HBV) infection is still a public health problem worldwide, being endemic in some parts of the world. It can lead to serious liver diseases such as chronic hepatitis, cirrhosis, and hepatocellular cancer. The differences in host immune response can be one of the reasons for the various clinical presentations of HBV infection. Polymorphisms of genes encoding the proinflammatory and antiinflammatory cytokines, which are responsible for regulation of the immune response, can affect the clinical presentation of the infection. Particularly, the polymorphisms of the genes encoding cytokines such as interleukin (IL)-1, IL-6, IL-8, IL-10, IL-18, IL-28B, interferon-γ, tumor necrosis factor-α, tumor growth factor-β1, and regulatory molecules like vitamin D receptor and chemokine receptor 5 can be responsible for different clinical presentations of HBV infections. The genomic information about cytokines and other mediators can be important for determining high-risk people for developing chronic hepatitis or hepatocellular cancer and may be used to plan treatment and preventive approaches for these people. In this review, the current knowledge in the literature on the association between cytokine/regulatory molecule gene polymorphisms and clinical course of chronic HBV infection is summarized, and the clinical implementations and future prospects regarding this knowledge are discussed.

Molecular mechanisms of gender disparity in hepatitis B virus-associated hepatocellular carcinoma

Chronic hepatitis B virus (HBV) infection is one of the most common causes of hepatocellular carcinoma (HCC), a malignant tumor with high mortality worldwide. One remarkable clinical feature of HBV-related HCC is that its incidence is higher in males and postmenopausal females compared to other females. Increasing evidence indicates that HBV-associated HCC may involve gender disparity and that it may be a type of hormone-responsive malignant tumor. Sex hormones, such as androgen and estrogen, have been shown to play very different roles in the progression of an HBV infection and in the development of HBV-related HCC. Through binding to their specific cellular receptors and affecting the corresponding signaling pathways, sex hormones can regulate the transactivation of HBx, cause the chronic release of inflammatory cytokines in the hepatocellular microenvironment, and participate in epigenetic and genetic alternations in hepatocytes. All of these functions may be related to the initiation and progression of HBV-associated HCC. A thorough investigation of the molecular mechanisms underlying the gender-related disparity in HBV-related HCC should provide a new perspective for better understanding its pathogenesis and exploring more effective methods for the prevention and treatment of this disease.

The interferon-gamma (IFN-γ) +874T allele reduces the risk of hepatitis B infection in an Asian population

Increasing evidence suggests that polymorphism of the interferon-gamma (IFN-γ) gene in the first intron at position +874 may be associated with chronic hepatitis B virus (HBV) infection and/or HBV clearance. However, the results of relevant studies have been inconsistent. To derive a more precise estimation of the association, we performed a meta-analysis. In total, 10 independent studies including 1661 chronic HBV-infected patients and 1142 controls were included in this meta-analysis. In studies following Hardy-Weinberg equilibrium (HWE), a significantly decreased risk of chronic HBV infection was associated with the IFN-γ + 874TT genotype in the overall population (TT vs AA: odds ratio (OR) = 0.714, 95% confidence interval (CI) = 0.526-0.969, P = 0.031) when compared with a spontaneously recovered population. Subgroup analysis by ethnicity revealed a similar association in Asian individuals (TT vs AA: OR = 0.706, 95% CI = 0.518-0.962, P = 0.028). Moreover, when compared with a healthy control group, the 874T allele was associated with a significant lower risk of chronic HBV infection in the overall populations (TA vs AA: OR = 0.439, 95% CI = 0.193-0.997, P = 0.049; TT + TA vs AA: OR = 0.475, 95% CI = 0.271-0.832, P = 0.009) and in Asian individuals (TA vs AA: OR = 0.862, 95% CI = 0.744-0.999, P = 0.048). In conclusion, the IFN-γ + 874TT genotype and 874T allele reduce the risk of chronic HBV infection in Asian individuals.

Correlation of OAS1 gene polymorphism at exon 7 splice accepter site with interferon-based therapy of HCV infection in Pakistan

The most useful treatment for HCV infection worldwide is peg-interferon plus ribavirin, although the response varies from person to person. Hence, host genetics are significantly involved in the treatment response to HCV infection. The 2'-5' oligoadenylate synthetase (OAS) is one of the most important components of the immune system having significant antiviral functions. The aim of this study was to investigate the role of single nucleotide polymorphism (SNP) at the exon 7 splice acceptor site (SAS) of OAS1 to interferon-based therapy of HCV infection. OAS1 genotyping was performed in 140 HCV patients by restriction fragment length polymorphism polymerase chain reaction method (RFLP-PCR). These patients were enrolled for the study in 2010-2013. OAS1 SNP was also established in 120 healthy controls. Correlation of HCV genotypes, OAS1 SNP, and other factors with response to interferon therapy were statistically analyzed by SPSS 13 software. There were no significant differences in the distribution of OAS1 genotypes between healthy and patients subjects. The distribution of AG and AA genotypes of OAS1 genotypes between sustained virological responders (SVRs) and the non-responders (NRs) group were also comparable. However, Pearson chi square analysis indicated that the patients possessing a GG genotype of the OAS1 gene at exon 7 SAS demonstrated significantly positive association with treatment response to HCV infection (p=0.039). This study determined that SNP at exon 7 SAS of OAS1 was significantly associated with response to interferon-based therapy of HCV infection in our population.

Association of polymorphisms in interleukin-18 and interleukin-28B genes with outcomes of hepatitis B virus infections: a meta-analysis

Several polymorphisms in the interleukin-18 (IL-18) and nterleukin-28B (IL-28B) genes have been reported to influence hepatitis B virus (HBV) infection. However, the published findings have been conflicting. We conducted meta-analyses of randomized, controlled trials to address the association of IL-18 or IL-28B polymorphisms and the outcomes of HBV infection. Weipu, Wanfang, CNKI, MEDLINE, PubMed, EMBASE, and Cochrane Library databases were employed to search for citations using the MeSH terms as "interleukin-18"/"interleukin-28B" AND "HBV" AND "gene" AND "polymorphism" without any restriction in language and publication year. Meta-analysis was conducted by RevMan 5.0 software. The results showed that the IL28B rs8099917 AA genotype (AA vs AC + CC: odds ratio (OR) = 0.63, 95 % confidence interval (CI) = 0.46-0.87) was associated with a decreased risk of hepatocellular carcinoma (HCC). Carriage of IL28B rs12979860 CC genotype was associated with an increased risk for developing liver cirrhosis among patients with HBV infection (CC vs CT + TT: OR = 1.39, 95 % CI = 1.04-1.85). Further well-designed large studies are warranted to confirm the mechanisms by which these are involved in these outcomes of HBV infection.

IFN-γ (+874) and not TNF-α (-308) is associated with HBV-HCC risk in India

Tumor necrosis factor (TNF)-α and interferon (IFN)-γ, the pro-inflammatory Th1 cytokines are the indispensable coordinators of the inflammatory responses involved in hepatitis B virus (HBV) pathogenesis. This study attempted to evaluate any possible association among TNF-α (-308G>A) and IFN-γ (+874T/A) genotypes, the spontaneous blood and mRNA levels and expression of their major signal transducers, namely STAT1 and NF-кB with hepatitis B virus-induced hepatocellular carcinoma (HCC) susceptibility in India. For this, 398 subjects (146 controls, 68 inactive-HBV-carriers, 64 chronic-active HBV patients, 61 HBV-cirrhotics, and 59 HBV-HCC subjects) were enrolled. Polymerase chain reaction-restriction fragment length polymorphism, allele-specific PCR, enzyme-linked immunosorbent assay, reverse transcriptase-PCR, and Western blot analysis were done for assessing polymorphism, blood levels, mRNA expression, and protein expression of signal transducers, respectively, of TNF-α and IFN-γ. The study revealed no significant association of TNF-α (-308) GA genotype, while a significant negative association of IFN-γ (+874) TA and AA genotypes, in HBV-HCC risk. Moreover, blood levels of TNF-α were significantly elevated as disease progresses to HCC, while IFN-γ levels were raised in HCC patients only. Besides, IFN-γ mRNA levels were significantly elevated in cirrhotics, with no change observed in TNF-α transcript levels. Moreover, NF-кB expression also consistently increased during HCC progression. These observations suggest a vital negative association of IFN-γ (+874) with HBV-HCC risk, with no significant association evident in TNF-α (-308). However, the TNF-α and IFN-γ levels markedly increased in HCC development.

TNF-α-308 polymorphism and risk of digestive system cancers: A meta-analysis

AIM: To evaluate the association between the tumour necrosis factor alpha-308 (TNF-α-308) gene polymorphism and the risk of digestive system cancers.

METHODS: All eligible case-control studies published up to December 2012 were identified by searching PubMed, Web of Science, Embase and China National Knowledge Internet without language restrictions. The risk of digestive system cancers associated with the TNF-α-308 polymorphism was estimated for each study using odds ratio (OR) together with its 95%CI, respectively. Cochrane Collaboration RevMan 5.1 was used to perform the analysis. A χ²-test-based Q statistic test and an I² test were performed to assess the between-study heterogeneity. When the Q test was significant (P < 0.05) or I² > 50%, the random effects model was used, otherwise the fixed effects model was used.

RESULTS: Fifty-eight studies from fifty-five publications with a total of 9986 cancer patients and 15511 healthy controls were included. Overall, a significant association was found between the TNF-α-308 polymorphism and the risk of digestive system cancers [dominant model: OR = 1.23, 95%CI: 1.09-1.39, (G/A) vs (G/G): OR = 1.15, 95%CI: 1.02-1.28, (A/A) vs (G/G): OR = 1.44, 95%CI: 1.19-1.73, recessive model: OR = 1.38, 95%CI: 1.15-1.66]. Furthermore, when the analysis was stratified by ethnicity, similar results were observed in both the Asian and Caucasian populations, except for the dominant model and heterozygote comparisons in the Asian population [dominant model: OR = 1.24, 95%CI: 0.99-1.56, (G/A) vs (G/G): OR = 1.09, 95%CI: 0.96-1.24]. When the cancer type subgroups were examined, similar results were detected in gastric and hepatocellular carcinomas; however, no significant association was observed among other digestive system cancers.

CONCLUSION: The TNF-α-308 gene polymorphism may be significantly associated with the risk of gastric and hepatocellular carcinomas, but not colorectal, pancreatic, or oesophageal cancer, in the Asian population.

Transforming Growth Factor- β 1 Gene Polymorphism (T29C) in Egyptian Patients with Hepatitis B Virus Infection: A Preliminary Study

The interindividual variations in the capacity of transforming growth factor- β 1 (TGF- β 1) production have been ascribed to genetic polymorphisms in TGF- β 1 gene. As pathogenesis of HBV has a genetic background, this preliminary study was designed to assess the impact of TGF- β 1 (T29C) on the susceptibility of Egyptians to HBV infection. Genotyping was performed using single stranded polymorphism-polymerase chain reaction (SSP-PCR) in 65 Egyptian hepatitis B patients and 50 healthy controls. TGF- β 1 plasma levels were measured using Enzyme-linked immunosorbent assay (ELISA). The frequency of CC genotype was significantly higher (P < 0.05) in HBV patients compared to controls. On the contrary, TC genotype did not show significant difference in both groups. TT genotype was significantly higher (P < 0.01) in controls than HBV patients. Our current preliminary data revealed that the frequency of the genotypes in the controls were within Hardy-Weinberg equilibrium (HWE) while the patients group was out of HWE (P < 0.01). TGF- β 1 was significantly (r = -0.684; P < 0.001) deceased in the sera of patients as compared to normal subjects. Depending on our preliminary work, CC genotype may act as a host genetic factor in the susceptibility to HBV infection in Egyptians. Taken together, the current data pointed to the importance of polymorphism of TGF- β 1 gene (T29C) in HBV infection.

An IFN-γ knockout mouse model of HBV persistence

AIM: To develop an interferon-γ (IFN-γ) knockout mouse model of HBV persistence.

METHODS: Nine IFN-γ knock-out (IFN-γ^-/-) mice were injected hydrodynamically with 10 micrograms of pAAV/HBV1.2 DNA via the tail vein. Nine wild-type C57BL/6 mice were used as controls. After injection, blood samples were regularly taken to monitor serum levels of HBsAg, HBeAg and HBV DNA. HBsAg and HBeAg were determined by electrochemiluminescence immunoassay (ECLIA) on an E170 analyzer. Total DNA was extracted from serum samples and used for detection of HBV DNA by real-time PCR.

RESULTS: Serum HBsAg, HBeAg and HBV DNA in IFN-γ^-/- mice were continuously positive until 40 days after the injection of the pAAV/HBV1.2 DNA. The levels and duration of serum HBsAg, HBeAg and HBV DNA in IFN-γ^-/- mice were similar to those in control mice. Serum HBsAg levels in IFN-γ^-/- mice were higher than those in wild-type C57BL/6 mice on day 40 post injection (P = 0.042). Serum HBV DNA levels in IFN-γ^-/- mice were persistently higher than those in wild-type C57BL/6 mice (P = 0.012, on day 25; P = 0.039, on day 40). No significant difference was observed in serum HBeAg levels between IFN-γ^-/- mice and control mice.

CONCLUSION: We have successfully developed an IFN-γ^-/- mouse model of HBV persistence. Our data suggest that IFN-γ could suppress HBV replication during chronic HBV infection.

Vitamin D and Tumor Necrosis Factor-Alpha Receptor Gene Polymorphisms in Various Hepatitis B Clinical Conditions in Turkey

Background

The aim is to define the role of single nucleotide polymorphism on the progress of hepatitis B virus (HBV) infection. We evaluated polymorphisms of TNF-α-308, Vitamin D receptor Apa I and Taq I gene in patients with HBV infection.

Methods

All subjects included were older than 18 years old. Sixty three patients had chronic HBV infection, 61 were HBsAg positive carriers and 59 were positive for anti-HBs and anti-HBc. Gene polymorphisms were evaluated by Amplification Refractory Mutation System PCR. For patients with chronic hepatitis, viral load, ALT levels, and histopathological evaluation of the liver were also compared.

Results

Gender distribution was not different among groups; however, anti-HBs positive patients were significantly older than the other patients. ALT levels and viral load were significantly higher in chronic hepatitis group than the asymptomatic carriers group. Vitamin D receptor Apa I gene and Taq I gene and TNF-α -308 gene variant alleles were not different in all three groups. Variant alleles of three genes were not different in subgroups of chronic hepatitis patients formed according to ALT levels, viral load, histological activity index, and fibrosis score.

Conclusions

Role of single nucleotide polymorphism in clinical status of various HBV infection states was not shown in this study. Considering the other studies performed with this aim, which strengthens the notion that ethnicity is an important factor, future studies with more patients from different ethnic groups may help to clear the role of polymorphisms in the clinical progress of HBV infection.

Polymorphic APOBEC3 modulates chronic hepatitis B in Moroccan population

The cytidine deaminase apolipoprotein B mRNA editing catalytic subunit-3 (APOBEC3) induces G-to-A hypermutation in hepatitis B virus (HBV) genomes and operates as part of the innate antiviral immune system. We investigated the associations between the presence of APOBEC3 variants and HBV carriage in a case-control study in the Moroccan population. A polymorphic deletion affecting the APOBEC3B gene and the H186R variant of APOBEC3G were genotyped in 179 HBV chronic carriers and 216 healthy control subjects. In addition, to assess the overall impact of APOBEC3 deaminases on circulating HBV, we looked for hyperedited forms of the viral genome using the 3DPCR technique and analysed editing context. Data analysis showed that there was no significant difference in the frequencies of deleted APOBEC3B alleles (P = 0.261) or genotypes (P = 0.333) between patients with chronic hepatitis B and control subjects. By contrast, subjects bearing deleted genotype had a faster progression of liver disease than those with the insertion genotype (adjusted OR, 3.72; 95% CI, 0.38-36.12). The analysis of the APOBEC3G H186R polymorphism revealed that R/R genotype frequencies were not significantly different in HBV infected patients and in healthy subjects. 3DPCR was positive in 26 samples (14%) among 179. Amplified viral segments displayed monomorphic G>A transitions highly reminiscent of APOBEC3G activity. Most intriguingly, hemi/homozygous carriers of the APOBEC3B deletion had significantly lower virus loads than patients with the wild type (median 539 vs. 2213 IU/mL, P = 0.0023). This result suggests that genetic variations in APOBEC3 cytidine deaminases do not predispose to chronicity but may modulate the course of persistent HBV infection.

Association between TGF-β1 polymorphisms and hepatocellular carcinoma risk: a meta-analysis

BACKGROUND

Associations between transforming growth factor (TGF)-β1 polymorphisms and hepatocellular carcinoma (HCC) risk remained controversial. Therefore, we performed this meta-analysis to investigate these associations.

METHODS

We searched Pubmed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases for studies before March 2013. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the strength of association.

RESULTS

A total of 14 studies were included in this meta-analysis. TGF-β1 +869C/T polymorphism was significantly associated with HCC risk (OR=1.74, 95% CI: 1.22-2.47, p=0.002). In addition, a significant association between -509C/T polymorphism and HCC risk was observed (OR=1.40, 95% CI: 1.15-1.70, p=0.0007). Furthermore, significant associations between these polymorphisms and HCC risk were found in Asians and population-based studies.

CONCLUSIONS

Our meta-analysis suggested that the TGF-β1 +869C/T and -509C/T polymorphisms may be risk factors for developing HCC.

Single nucleotide polymorphisms rs2120131, rs4935047, and rs7095891 in the MBL2 gene show no association with susceptibility to chronic hepatitis B in a Chinese Han population

Thus far, many studies have evaluated the correlation between MBL2 gene polymorphisms and hepatitis B infection. Tag single nucleotide polymorphisms (SNPs) were used to investigate the relationship between MBL2 gene polymorphisms and susceptibility to chronic hepatitis B virus (HBV) infection by comparing 996 chronic HBV infection cases to 301 acute infection controls. There was no significant correlation between rs2120131, rs4935047, and rs7095891 and chronic HBV infection. This suggested that the new SNPs within MBL2 were not associated with susceptibility to chronic hepatitis B in a Chinese Han population.

Role of HLA-DP polymorphisms on chronicity and disease activity of hepatitis B infection in Southern Chinese

BACKGROUND AND AIMS

The association between HLA-DP single nucleotide polymorphisms (SNPs) and chronic hepatitis B virus (HBV) infection varies between different populations. We aimed to study the association between HLA-DP SNPs and HBV infection and disease activity in the Chinese population of Hong Kong.

METHODS

We genotyped SNPs rs3077 (near HLA-DPA1) and rs9277378 and rs3128917 (both near HLA-DPB1) in 500 HBV carriers (hepatitis B surface antigen [HBsAg]-positive), 245 non-HBV infected controls (HBsAg- and antibody to hepatitis B core protein [anti-HBc]-negative), and 259 subjects with natural HBV clearance (HBsAg-negative, anti-HBc-positive). Inactive HBV carriers state was defined by HBV DNA levels <2,000 IU/ml and persistently normal alanine aminotransferase level for least 12 months.

RESULTS

Compared to the non-HBV infected subjects, the HBV carriers had a significantly lower frequency of the rs3077 T allele (p = 0.0040), rs9277378 A allele (p = 0.0068) and a trend for lower frequency of rs3128917 T allele (p = 0.054). These alleles were associated with an increased chance of HBV clearance (rs3077: OR = 1.41, p = 0.0083; rs9277378: OR = 1.61, p = 0.00011; rs3128917: OR = 1.54, p = 0.00017). Significant associations between HLA-DP genotypes and HBV clearance were also found under different genetic models. Haplotype TAT was associated with an increased chance of HBV clearance (OR = 1.64, p = 0.0013). No association was found between these SNPs and HBV disease activity.

CONCLUSION

HLA-DP SNPs rs3077, rs9277378 and rs3128917 were associated with chronicity of HBV disease in the Chinese. Further studies are required to determine whether these SNPs influence the disease endemicity in different ethnic populations.

Association of the rs3077 and rs9277535 polymorphisms in HLA-DP with hepatitis B virus infection and spontaneous clearance: a meta-analysis

PURPOSE

Owing to inconsistent observations in the literature of an association between HLA-DP polymorphisms (rs3077 and rs9277535) and hepatitis B virus (HBV) infection and spontaneous clearance, there is an urgent need for a comprehensive and reliable understanding of this subject. This meta-analysis was performed to quantitatively summarise the evidence for the relevance of these HLA-DP polymorphisms to HBV infection and spontaneous clearance.

METHODS

A meta-analysis was conducted with the data from eight relevant papers published from April 2009 to March 2012, following strict selection. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for alleles, co-dominant, dominant and recessive genotype models of the rs3077 and rs9277535 loci.

RESULTS

Our analysis indicated a significant association of rs3077 and rs9277535 in HLA-DP with HBV infection, suggesting that these HLA-DP polymorphisms act beneficially against HBV infection (for rs3077, AG vs. GG: OR = 0.522, 95% CI = 0.485-0.561; AA vs. GG: OR = 0.350, 95% CI = 0.311-0.393; for rs9277535, AG vs. GG: OR = 0.542, 95% CI = 0.506-0.579; AA vs. GG: OR = 0.371, 95% CI = 0.336-0.409). Additionally, these HLA-DP polymorphisms served as protective factors in the spontaneous clearance of HBV (for rs3077, AG vs. GG: OR = 0.600, 95% CI = 0.464-0.775; AA vs. GG: OR = 0.420, 95% CI = 0.299-0.590; for rs9277535, AG vs. GG: OR = 0.623, 95% CI = 0.570-0.681 and AA vs. GG: OR = 0.464, 95% CI = 0.386-0.556) with similar results for both dominant and recessive genotype models.

CONCLUSIONS

Our results demonstrated that the rs3077 and rs9277535 HLA-DP polymorphisms reduced HBV infection and increased the likelihood of spontaneous viral clearance in some Asian populations.

No correlation between interleukin-10 gene promoter polymorphisms and hepatitis B virus infection outcome

BACKGROUND

Single nucleotide polymorphisms (SNP) in the promoter region of the interleukin (IL)-10 genes have a role in determining hepatitis B virus (HBV) outcome.

OBJECTIVES

This study evaluates the correlation between HBV infection and SNP in IL-10 gene promoter.

PATIENTS AND METHODS

Ninety-six HBV-infected patients (32 chronic hepatitis B infection patients, 34 healthy carriers, 30 spontaneously recovered cases) and 31 healthy controls were enrolled. Three biallelic (-819,-592,-1082) regions in the IL-10 gene promoter were sequenced for all patients.

RESULTS

Genotypes and haplotypes of IL-10 gene promoter region at position -1082, -819 and -592 were not significantly different among controls, HBV recovered cases, carriers and chronic HBV patients. Nevertheless, A/A genotype at position -592 and T/T genotype at position -819 were more frequently seen in the HBV clearance group, while frequency of G/G genotype at position -1082 was more prevalent in the persistence group. GCC/GCC and GCC/ACC haplotypes were significantly observed in anti-HBe positive individuals.

CONCLUSIONS

Our findings showed that IL-10 promoter polymorphisms were not correlated with HBV infection prognosis. Nevertheless, individuals carrying high and intermediate producer of IL-10 haplotypes had a better ability to develop anti-HBe than low producer carriers.

Gene polymorphism of transforming growth factor-β1 in Egyptian patients with type 2 diabetes and diabetic nephropathy

Role of the transforming growth factor-β1 (TGF-β1) gene polymorphisms located at codons 10 and 25 in the genetic predisposition to type 2 diabetes (T2D) and in diabetic nephropathy (DN) in Egyptian patients was investigated. A case control study was done for 99 unrelated Egyptian patients with T2D (50 DN(-) and 49 DN(+)) and 98 age- and sex-matched healthy controls. TGF-β1 T869C (codon 10) and G915C (codon 25) polymorphism detection was done by amplification refractory mutation system method. DN(+) patients were younger, with higher body mass index, serum triglycerides, serum creatinine, and lower serum albumin than those in DN(-) patients. Moderate and bad grades of diabetic control were associated with DN (P < 0.001). The TGF-β1 (T869C) C allele, TC and TC + CC genotypes were significantly higher in patients; the T allele and TT genotype were significantly higher in controls (Pc < 0.001). The TGF-β1 TC genotype was associated with DN (Pc < 0.05). Non-significant differences were detected between T2D patients and controls in the frequencies of TGF-β1 (G915C) alleles and genotypes. In conclusion, these preliminary data showed that the TGF-β1 codon 10 C allele, and C allele-containing genotypes may be susceptible, and T allele/TT genotype may be protective factors for T2D and DN(+) complications.

YKL-40-gene polymorphism affects acute cellular rejection and fibrosis progression after transplantation for hepatitis C virus-induced liver disease

BACKGROUND AND AIM

The development of end-stage graft disease is suspected to be partially determined by an individual genetic background. The aim of our study was to determine the prevalence of YKL-40-gene polymorphism in hepatitis C virus (HCV)-positive patients and its impact on the incidence of acute cellular rejection (ACR), graft fibrosis and antiviral treatment response.

METHODS

A total of 149 patients, who underwent liver transplantation for HCV-induced liver disease, were genotyped for YKL-40 (rs4950928; G/C) by TaqMan Genotyping Assay. The results were correlated with 616 post-transplant graft biopsies regarding inflammation, fibrosis and evidence for ACR.

RESULTS

No association of YKL-40-genotypes was observed regarding mean inflammation grade (P = 0.216) and antiviral treatment outcome (P = 0.733). However, the development of advanced fibrosis (F3-4) was significantly faster in patients with YKL-40-G-allele: t(CC) = 4.6 versus t(CG/GG) = 2.4 years; P = 0.006. Patients with lower fibrosis (F0-2) compared to advanced fibrosis (F3-4) received significantly more frequent dual immunosuppression (calcineurin inhibitors [CNIs]/mofetile mycophenolate [MMF] vs CNIs; P = 0.003). ACR-occurrence was associated with YKL-40-genotypes (ACR: CC = 60.4%, CG = 25.0% and GG = 14.6% vs non-ACR: CC = 74.2%, CG = 23.8% and GG = 2.0%; P = 0.009) and with gender compatibility between donor and recipient (P = 0.012).

CONCLUSION

Fibrosis progression and ACR-incidence after transplantation for HCV-induced liver disease seem to be under genetic control. The negative impact of G-allele on post-transplant events observed in our study, deserves attention and should be verified in larger liver transplantation-cohorts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Polymorphisms within the Promoter Region of the Gamma Interferon (IFN-γ) Receptor1 Gene are Associated with the Susceptibility to Chronic HBV Infection in an Iranian Population

BACKGROUND

chronic hepatitis B virus (HBV) infection is a multifactorial disease that can result in serious clinical complications. Host genetic background especially the genes that encode immunologic factors like INF-γ and its receptor (IFN-γ R) are critical in the pathogenesis of infection.

OBJECTIVES

The current study aimed to investigate the association between two single nucleotide polymorphisms (SNPs) at positions -611 and -56 within the promoter region of gamma interferon receptor1 gene (IFN-γ R1) and chronic HBV infection.

MATERIALS AND METHODS

Genomic DNA from peripheral blood samples of 200 chronically HBV infected patients and 200 healthy blood donors, as controls, were collected and genomic DNA was extracted by phenol-chloroform method and DNA analysis genotype identification was performed by PCR-RFLP.

RESULTS

The results indicated that both SNP's frequency had a significant difference in the patient and control groups. At position -56, TT genotype was associated with patient group and P value was 0.002 and at position -611, GG genotype was further observed in control group and P value was 0.006.

CONCLUSIONS

Presence of G allele at position -611 within promoter of IFN-γ R1 gene in the enrolled population for the study was related to lower risk of disease, and presence of T allele at position -56 was also related to susceptibility to chronic HBV infection. Men had higher frequency of chronic HBV infection, which might be the result of high risk behavior.

Association of Ephrin receptor A3 gene polymorphism with susceptibility to chronic severe hepatitis B

AIM

  Previous research has suggested that Ephrin receptor A3 (EphA3) plays signaling roles in the processes of inflammation by regulating lymphocyte migration and proliferation. In this study, we investigated whether the EphA3 gene polymorphism was associated with disease progression of chronic hepatitis B virus (HBV) infection.

METHODS

  The EphA3 variant rs9310117 was genotyped in 1245 unrelated Han Chinese HBV carriers including 800 cases and 445 controls. χ(2) test was used to examine the difference in allele frequencies and genotype distributions between groups. The association between the polymorphism and disease progression of HBV infection was conducted by unconditional logistic regression analysis.

RESULTS

  Statistical analysis revealed that the genetic variant was significantly associated with the occurrence of chronic severe hepatitis B (CSHB). We observed that subjects bearing at least one T allele (C/T or T/T genotype) had a decreased susceptibility to chronic severe hepatitis B compared with those bearing C/C genotype (P = 0.003, odds ratio = 0.560; 95% confidence interval, 0.381-0.824, recessive model). Genotype C/T had also been confirmed to protect subjects from suffering chronic severe hepatitis B (P = 0.001, odds ratio = 0.498; 95% confidence interval, 0.330-0.752, additive model).

CONCLUSION

  Our results suggest that the genetic alteration at EphA3 locus plays a role in the occurrence of chronic severe hepatitis B.

Relationship between HLA-DR gene polymorphisms and outcomes of hepatitis B viral infections: A meta-analysis

AIM: To assess the rigorous relationship between human leukocyte antigens (HLA)-DR alleles and outcomes of hepatitis B virus (HBV) infections by means of meta-analysis.

METHODS: Medline/PubMed, EMBASE, CNKI and VIP were searched to identify relevant studies. Study quality was evaluated using the Newcastle-Ottawa Scale. Odds ratios (OR) and 95% confidence interval (95% CI) were pooled using Stata 11.0. Subgroup analyses were performed by ethnicity. Heterogeneity and publication bias analyses were performed to validate the credibility.

RESULTS: A total of 2609 patients with chronic hepatitis B and 2606 controls spontaneously recovering from prior HBV infection were included. Meta-analysis showed that HLA-DR*04 (OR = 0.72, 95% CI: 0.60-0.85) and DR*13 (OR = 0.27, 95% CI: 0.19-0.37) alleles were significantly associated with HBV clearance while patients carrying HLA-DR*03 (OR = 1.47, 95% CI: 1.16-1.87) or DR*07 (OR = 1.59, 95% CI: 1.24-2.03) alleles had a significantly increased risk of chronic HBV persistence. For the HLA-DR*01 polymorphism, a significantly association with HBV clearance was found in Chinese Han group (OR = 0.48, 95% CI: 0.26-0.86), but not found in other ethnic groups (P = 0.191). For other polymorphisms, no association with the HBV infection outcome was found.

CONCLUSION: HLA-DR*04 and DR*13 alleles may be the protective factors for HBV clearance and HLA-DR*03, and DR*07 alleles may be the risk factors for HBV persistence.

Persistent hepatitis B viral replication in a FVB/N mouse model: impact of host and viral factors

The mechanism underlying the chronicity of hepatitis B virus (HBV) infection has long been an interesting question. However, this mechanism remains unclear largely due to the lack of an animal model that can support persistent HBV replication and allow for the investigation of the relevant immune responses. In this study, we used hydrodynamic injection to introduce HBV replicon DNA into the livers of three different mouse strains: BALB/c, C57BL/6, and FVB/N. Interestingly, we found that an HBV clone persistently replicated in the livers of FVB/N mice for up to 50 weeks but was rapidly cleared from the livers of BALB/c and C57BL/6 mice. Flow cytometric analysis and quantitative reverse transcription PCR analysis of the mouse livers indicated that after DNA injection, FVB/N mice had few intrahepatic activated cytotoxic T lymphocytes (CTLs) and produced low levels of alanine aminotransferase, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and the CXCL9 and CXCL10 chemokines. These findings were in sharp contrast with those observed in BALB/c and C57BL/6 mice, reflecting a strong correlation between the degree of liver inflammation and viral clearance. Mutational analysis further demonstrated that a change of Asn-214 to Ser-214 in the HBV surface antigen rendered the persistent HBV clone clearable in FVB/N mice, which was accompanied by increased levels of activated CTL and upregulated expression of IFN-γ, CXCL9, and CXCL10 in the livers. These results indicate that the heterogeneity of the host factors and viral sequences may influence the immune responses against HBV. An inadequate activation of immune or inflammatory responses can lead to persistent HBV replication in vivo.

The influence of human leukocyte antigen and IL-10 gene polymorphisms on hepatitis B virus outcome

CONTEXT

The clinical outcome of hepatitis B virus (HBV) infection is variable, ranging from spontaneous recovery to an inactive carrier state, chronic hepatitis, occult HBV infection, liver cirrhosis, or hepatocellular carcinoma.

EVIDENCE ACQUISITION

This variable pattern and clinical outcomes of the infection were mainly determined by virological and host genetic factors. Since the most of host genetic factors associated with HBV infection have currently focused on human leukocyte antigen (HLA) associations and interleukin (IL)-10 gene polymorphisms, this review focuses on the recent progresses in these issues to provide prognostic markers for the outcome of HBV infection.

RESULTS

A study on serum levels of IL-10 in occult HBV infected patients reported that the higher level of IL-10 production may suppress function of the immune system against HBV in patients with occult HBV infection. IL-10 promoter polymorphism at position -592 is associated with susceptibility to occult HBV infection.

CONCLUSIONS

Findings of this study suggest that the host HLA polymorphism is an important factor in determining outcome of HBV infection but regarding IL-10 gene promoter polymorphisms, we are still have a long way to achieve a definite conclusion.

Relationship between interleukin 18 polymorphisms and susceptibility to chronic hepatitis B virus infection

AIM

To identify the relationship between the tagging single nucleotide polymorphism sites (tagSNPs) of the Interleukin-18 (IL-18) gene and genetic susceptibility to chronic hepatitis B virus infection in Chinese patients.

METHODS

Five hundred and one cases of chronic hepatitis B virus (HBV) infection and 301 HBV natural clearance controls were studied. Two tagSNPs in the IL-18 gene (rs1946518A/C and rs574424C/G) were genotyped by the Multiplex Snapshot technique. The genotype and allele frequencies were calculated and analyzed.

RESULTS

In the genotypes of rs1946518, the AA type was present at a higher frequency in the patients compared to those in the controls. Odds ratio (OR) of the AA genotype for the comparison with that of the AC and the CC genotype was 1.537 (95% confidence intervals (CI): 1.116-2.218, P = 0.009 < 0.025). In phenotypes, the allele C at rs1946518 was of a significantly lower frequency in the patients with chronic hepatitis B than that in the controls (P = 0.017 < 0.025). OR of the allele A for the comparison with that of the allele C was 1.279 (95% CI: 1.045-1.567). As for the rs574424 genotypes, no significant difference in this genotype distribution or in this allele frequency between the patients and the control subjects was observed. No significant difference in the haplotype frequencies between the patients with chronic hepatitis B and HBV natural clearance individuals was displayed.

CONCLUSION

The data suggest that genotype AA and the allele A of the IL-18 at position rs1946518 are closely associated with the resistance to chronic hepatitis B and may be the dangerous gene. However, no statistical association was found between polymorphisms of rs574424 for IL-18 and hepatitis B.

Tumor necrosis factor-α -308 G>A and interleukin-6 -174 G>C promoter polymorphisms and pemphigus

The objective of this study was to analyze the possible involvement of the tumor necrosis factor (TNF)-α -308 G>A and interleukin-6 (IL-6) -174 G>C polymorphisms in the susceptibility and/or disease profile of pemphigus in Egyptian patients. Detection of TNF-α -308 G>A by amplification refractory mutation system and IL-6 -174 G>C by restriction fragment length polymorphism was performed for 70 patients and 203 controls. No significant differences were observed in the distribution of TNF-α -308 in pemphigus patients and controls. However, GA+AA genotypes were more frequent in pemphigus vulgaris (PV) patients only versus controls (p(c) = 0.046). The frequency of the C allele and CC/GC genotypes of IL-6 -174 was significantly higher in pemphigus patients and those with the 2 major clinical forms (PV and pemphigus foliaceus [PF]) compared with controls (p < 0.05). Comparison of the distribution of TNF-α -308 and IL-6 -174 variants in relation to clinical type of pemphigus (PV versus PF), activity score, recurrence, and demographic data of patients revealed no significant associations. The IL-6 -174 CC genotype represents a marker of increased susceptibility to pemphigus in Egyptian patients and GG genotype can be considered a low-risk genotype; TNF-α -308 A-containing genotypes contribute to the susceptibility to PV only.

Association of interleukin 10 and interferon gamma gene polymorphisms with enterovirus 71 encephalitis in patients with hand, foot and mouth disease

Enterovirus 71 (EV71) is one of the common causative agents of hand, foot and mouth disease (HFMD), and is associated with several outbreaks with neurological complications including encephalitis. This study investigated the polymorphisms of interferon gamma (IFN-γ)+874 T/A and interleukin 10 (IL-10)-1082 G/A in 65 Chinese patients with EV71 encephalitis and 113 Chinese HFMD patients without complications. The polymorphisms of IFN-γ+874 T/A and IL-10-1082 G/A were determined by polymerase chain reaction (PCR)-amplification refractory mutation system (ARMS) and PCR-sequence-specific primer (SSP) analysis, respectively. The IFN-γ + 874 A allele was observed with significantly greater frequency in patients with EV71 encephalitis (76.2%) compared with HFMD patients without complications (61.1%, p < 0.01). Similarly, the IL-10 - 1082 A allele was observed with significantly greater frequency in patients with EV71 encephalitis (86.2%) compared with HFMD patients without complications (77.0%, p < 0.05). IFN-γ + 874 A and IL-10 - 1082 A alleles are associated with susceptibility to EV71 encephalitis in Chinese patients.

Association of a TANK gene polymorphism with outcomes of hepatitis B virus infection in a Chinese Han population

The host genetic compound plays a vital role in determining clinical outcomes of hepatitis B virus (HBV) infection. The tumor necrosis factor receptor-associated factor family member-associated nuclear factor-κB (NF-κB) activator (TANK) takes part in the tumor necrosis factor-α (TNF-α)-mediated NF-κB signaling pathway and the interferon (IFN)-induction pathways that have relevance to HBV-related liver disease. In this report, we explored whether the intronic polymorphism rs3820998 of the TANK gene was associated with outcomes of HBV infection by binary logistic regression analysis. A total of 1305 unrelated Han Chinese patients recruited from Wuhan, including 180 acute-on-chronic hepatitis B liver failure (ACLF-HBV) patients, 331 HBV-related liver cirrhosis (LC) patients, 308 HBV-related hepatocellular carcinoma (HCC) patients, and 486 asymptomatic HBV carriers (AsC) were genotyped using the TaqMan probe method. Logistic analysis revealed that the single-nucleotide polymorphism (SNP) rs3820998 was significantly associated with susceptibility to ACLF-HBV (dominant model, OR 0.643, 95% CI 0.428,0.964, p=0.033; additive model, OR 0.640, 95% CI 0.414,0.990, p=0.045), and LC (recessive model, OR 0.398, 95% CI 0.164,0.966, p=0.042; additive model, OR 0.379, 95% CI 0.155,0.928, p=0.034). These results indicate that the G > T variant is a protective factor in the development of ACLF-HBV and LC, and that the SNP rs3820998 in the TANK gene may play a role in mediating susceptibility to ACLF-HBV and LC in a Chinese Han population.

Tumor necrosis factor-alpha -308G/A polymorphism and risk of hepatocellular carcinoma in hepatitis C virus-infected patients

Tumor necrosis factor-alpha (TNF-α) is an important cytokine in generating an immune response against infection with hepatitis C virus (HCV). The functions of TNF-α may be altered by single-nucleotide polymorphisms (SNPs) in its gene structure. We hypothesized that SNPs in TNF-α may be important in determining the outcome of an HCV infection. To test this hypothesis, we investigated the role of the polymorphism -308G/A, which is located in the promoter region of the TNF-α gene, in the progression of HCV infection in Egyptian patients using a quantitative real-time polymerase chain reaction (qRT-PCR). The distribution of this polymorphism and its impact on the serum level of TNF-α was compared between 90 HCV-infected patients [45 with HCV-induced cirrhosis and 45 with HCV-related hepatocellular carcinoma (HCC)] and 45 healthy Egyptian volunteers without any history of liver disease. Our results showed that at the TNF-α -308 position, the G/G allele was most common (78.5%) in the study population, with the G/A and A/A alleles occurring less frequently (13.3% and 8.1%, respectively). Frequencies of G/G, G/A, and A/A genotypes were 87%, 7%, and 6% in patients with liver cirrhosis and were 94%, 4%, and 2% in patients with HCC, respectively. Serum levels of TNF-α were significantly higher in HCV-infected patients than in healthy controls, indicating that the TNF-α -308 polymorphism does not influence the production of TNF-α. The serum level of TNF-α was positively correlated with HCV infection. Taken together, these findings suggest that the TNF-α -308 polymorphism may not be a host genetic factor associated with the severity of HCV infection, but may be an independent risk factor for HCC.

Polymorphisms of toll-like receptors and their pathways in viral hepatitis

Toll-like receptors (TLRs) are an important part of the innate immune response to a variety of pathogens including hepatic viral infections. Activation of TLRs stimulates a complex intracellular signalling cascade that results in production of proinflammatory cytokines and interferons important for antiviral responses as well as induction of the adaptive arm of the immune system. There is substantial evidence for an important role for TLRs and TLR-mediated signalling in the pathogenesis and outcomes of hepatitis B and C in particular, but it might also influence responses to other viral hepatitis infections. Several single nucleotide polymorphisms (SNPs) of TLRs, relevant adaptor molecules and cytokines mediated by TLR signalling have been described that alter innate immune responses and have been implicated in a variety of human diseases including viral and other infections. There is now significant evidence that a number of TLR SNPs can affect various clinical outcomes in Caucasian patients with chronic HCV. However, the role of these polymorphisms in acute and other chronic hepatitis infections, including HBV as well as in non-Caucasian populations, has not been elucidated. In addition, results for SNPs downstream of TLR activation, such as in relevant cytokines, are inconsistent and their influence requires further investigation to determine the clinical significance of genetic variations in these mediators.