Association of interferon-gamma gene haplotype in the Chinese population with hepatitis B virus infection

Interleukin 6 and interferon gamma haplotypes are related to cytokine serum levels in dogs in an endemic Leishmania infantum region

BACKGROUND

The Ibizan Hound is a canine breed native to the Mediterranean region, where leishmaniasis is an endemic zoonosis. Several studies indicate a low prevalence of this disease in Ibizan Hound dogs, whereas other canine breeds present a high prevalence. However, the underlying molecular mechanisms still remain unknown. The aim of this work is to analyse the relationship between serum levels of cytokines and the genomic profiles in two canine breeds, Ibizan Hound (resistant canine breed model) and Boxer (susceptible canine breed model).

METHODS

In this study, we analyse the haplotypes of genes encoding cytokines related to immune response of Leishmania infantum infection in twenty-four Boxers and twenty-eight Ibizan Hounds apparently healthy using CanineHD DNA Analysis BeadChip including 165,480 mapped positions. The haplo.glm extension of haplo.score was used to perform a General Linear Model (GLM) regression to estimate the magnitude of individual haplotype effects within each cytokine.

RESULTS

Mean levels of interferon gamma (IFN-γ), interleukin 2 (IL-2) and IL-18 in Boxer dogs were 0.19 ± 0.05 ng/ml, 46.70 ± 4.54 ng/ml, and 36.37 ± 30.59 pg/ml, whereas Ibizan Hound dogs present 0.49 ± 0.05 ng/ml, 64.55 ± 4.54 ng/ml, and 492.10 ± 31.18 pg/ml, respectively. The GLM regression shows fifteen haplotypes with statistically significant effect on the cytokine serum levels (P < 0.05). The more relevant are IL6-CGAAG and IFNG-GCA haplotypes, which increase and decrease the IL-2, IL-8 and IFN-γ serum levels, respectively.

CONCLUSIONS

Haplotypes in the IFNG and IL6 genes have been correlated to serum levels of IFN-γ, IL-2 and IL-18, and a moderate effect has been found on IL8 haplotype correlated to IL-8 and IL-18 serum levels. The results indicate that the resistance to L. infantum infection could be a consequence of certain haplotypes with a high frequency in the Ibizan Hound dog breed, while susceptibility to the disease would be related to other specific haplotypes, with high frequency in Boxer. Future studies are needed to elucidate whether these differences and haplotypes are related to different phenotypes in immune response and expression gene regulation to L. infantum infections in dogs and their possible application in new treatments and vaccines.

Genetic associations in chronic hepatitis B infection: toward developing polygenic risk scores

Chronic hepatitis B (CHB) infection results in multiple clinical phenotypes of varying severity. One of the critical gaps in CHB management is the lack of a genetic-based tool to aid existing hepatocellular carcinoma and cirrhosis risk stratification models for patients with active CHB. Such individual predictive models for CHB are plagued by an inherent limitation of discriminatory power that clearly indicates the need for their improvement. In this article, we highlight genetic association studies in CHB that identified HLA and cytokine genetic susceptibility loci to CHB. We advance the position that translating CHB genetic susceptibility loci into polygenic risk scores will be a welcome addendum to the current arsenal of CHB outcome predictive models. We conclude with comments on hurdles that future research efforts should address within the research enclave of CHB and advocate for increased genetic data representation from sub-Saharan Africa.

The Impact of Interferon-γ (IFN-γ) and IFN-γ-Inducible Protein 10 (IP-10) Genes' Polymorphism on Risk of Hepatitis C Virus-Related Liver Cirrhosis

Background: Today there is increasing evidence concerning the association between individual genetic polymorphisms within proinflammatory cytokines and chronic hepatitis C (CHC) severity. It has been demonstrated that polymorphisms in some genes may significantly predict HCV infected patients' susceptibility to developing liver cirrhosis or their responsiveness to the treatment.Aim: We investigated the influence of single nucleotide polymorphisms (SNPs) in Interferon (IFN-γ) and Interferon Gamma-Inducible Protein 10 (IP-10) genes on cirrhosis risk in HCV-infected patients and their association with response to various direct-acting antiviral drugs (DAAs).Methods: IFN-γ (+874T/A, +2109A/G) and IP-10 (-135G/A, -1447A/G) genotypes were determined in 175 CHC Egyptian HCV patients (69 liver cirrhotic and 106 non-cirrhotic patients) using either single-stranded polymorphism polymerase chain reaction (SSP-PCR) or Restriction fragment length-PCR (RFLP-PCR) methods.Results: IFN-γ + 874 TA, IP-10 - 135AA, and IP-10 - 1447AA and IP-10 - 1447GG genotypes are increased in patients developing liver cirrhosis compared to non-cirrhotic ones. Although, no statistical significance in their distribution was demonstrated, indicating the lack of association between these SNPs and liver cirrhosis susceptibility in HCV-infected patients. Haplotypes analysis between different loci on all selected genes showed a significant increase in AGGA and TAGA and a significant decrease in TGGA haplotypes in cirrhotic patients. Genotype frequencies at loci -135 and -1447 of IP-10 appeared to be in complete Linkage disequilibrium (LD) (D' = 0.999, r² = 0.689).Conclusion: Our data support the concept that IFN-γ and IP-10 gene polymorphisms are not predictors of disease progression among Egyptian patients with HCV infection.

Human genetic susceptibility to hepatitis B virus infection

Hepatitis B virus (HBV) infection is still a serious health threat worldwide. The outcomes of HBV infection consist of spontaneous HBV clearance and chronic HBV infection. Multiple factors contribute to the disparity of HBV infection outcomes, including host factors, viral factors and environmental factors. The present review comprehends the current researches mainly focusing on the relationships between genetic determinants, including single nucleotide polymorphisms (SNPs) and haplotypes, and susceptibility of HBV infection, namely chronic (persistent) HBV infection and HBV clearance. A number of determinants in the chromosomes, including mutations in human leukocyte antigens (HLAs), cytokines genes, toll-like receptors (TLRs), and other genes are related to the human susceptibility to HBV infection. Among the above variants, some of those in HLAs have been studied and replicated in multiple-ethnic populations and came to consistent conclusions, while some others are novel and need to be evaluated further.

Interferon gamma gene polymorphisms and chronic hepatitis B infections in an Iranian population

BACKGROUND AND AIMS

Chronic hepatitis B is an important health problem in all countries. I Interferon gamma is a pro-inflammatory Th1 cytokines, which can exert antiproliferative and antitumor activity. Some SNPs in IFN-γ and IFN-γR1 genes may influence the susceptibility to HBV. Here, we evaluated the impact of interferon gamma (+874 T/A) and its receptor (-611A/G, +189G/C and +95C/T) polymorphisms and the risk of HBV in Iranian patients.

MATERIALS AND METHODS

SNPs of interferon gamma and its receptor genotypes were determined in 221 infected patients with HBV and 200 people without HBV using ARMS-PCR and PCR- RFLP method.

RESULTS

In this study, we showed an obvious relationship between IFN-γ SNPs and susceptibility to chronic HBV. Our findings suggest that IFN-γ-874A allele increases the risk of disease and carriers of the T allele have reduced susceptibility to infection. In addition, there was not any relationship between the -611A/G, +189G/C and +95C/T regions of IFN-γ R1 and HBV.

CONCLUSIONS

Our observations demonstrate +874 T/A SNP as a predicting factor in patients who have the risk of HBV.

IFN-γ and TNF-α Gene Polymorphisms in Multiple Sclerosis Patients in Northwest Iran

BACKGROUND

Cytokines are polypeptides that play critical roles in immune responses. Gene polymorphisms occurring in the inflammatory cytokines are taking a role in autoimmune diseases, including multiple sclerosis (MS), which may induce inappropriate immune responses.

OBJECTIVE

The aim of this study was to investigate the allelic and genotypic frequencies of interferon gamma gene (IFN-γ) at +874A/T locus and tumor necrosis factor (TNF-α) at+308A/G locus in MS patients of Azeri population.

METHODS

At first, a questionnaire was prepared for each of 240 healthy, non-relative, and 152 Azeri MS patients before obtaining the blood sample from all subjects. After DNA extraction, the frequency of alleles and genotypes of the IFN-γ and TNF-α genes at +874A/T and -308G/A loci, respectively, were determined by allele-specific PCR method. Finally, the frequencies were compared between control and MS patients by chi-square test (x²-test) and p<0.05 was considered significant.

RESULTS

In the IFN-γ +874A/T gene single nucleotide polymorphism (SNP), the most allelic and genotypic frequencies in MS patients were the A allele, 55.26% (p=0.04) and the AT genotype, 52.63% (p=0.048). In healthy individuals, it was 65.42% for the A allele and 45.42% for the AA genotype. For the TNF-α 308 G/A SNP, the highest allelic and genotypic frequencies in MS patients were the G allele with 55.92% (p<0.001) and AG genotype with 61.84%, and in healthy subjects, the allelic and genotypic frequencies were 84.2% and 70.8% for the G allele and GG genotype, respectively.

CONCLUSION

Head trauma, the infection with the herpes virus and Mycoplasma pneumonia, frequent colds and high consumption of canned foods provide grounds for MS. The T allele in the IFN-γ gene (+874) and the genotypes of AA and AG at the TNF-α gene (-308) at the position-308 were considered as potential risk factors for MS. Therefore, the polymorphisms in cytokine genes and following changes in their expression levels can be effective in susceptibility to MS.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

Interferon Gamma Gene Polymorphism (+874 T > A) and Chronic Hepatitis B in the Population of Gorgan, North-Eastern Iran

Background

Based on differences in individual immune responses to the hepatitis B virus (HBV), between 5% and 10% of patients become persistently infected with the virus, which leads to the determination of chronic HBV. Cytokines such as interferon gamma (IFN-γ) are secretory proteins that play important roles in both innate and adaptive immune responses. Functional studies have demonstrated that the IFN + 874A/T gene polymorphism can increase or decrease the overall expression of IFN-gamma (γ) and ultimately determine the outcome of the infection.

Objectives

This study was performed to investigate the relationship between the IFN-γ + 874 gene polymorphism and susceptibility to chronic HBV infection.

Methods

Polymorphism detection analysis was performed on 598 subjects from North-Eastern Iran. The IFN-γ gene polymorphism (+ 874A/T) was genotyped through a specific sequence primer polymerase chain reaction (SSP-PCR).

Results

The frequencies of the AA, AT, and TT genotypes were 31%, 51%, and 18% in the chronic HBV patient group, and 40%, 45%, and 15% in the healthy control group, respectively. However, a lack of association of the + 874 polymorphism in the IFN-γ gene of those with chronic HBV infection was found. Evaluation of HBV association with this polymorphism was significant under the dominant genetic model (P = 0.04).

Conclusions

Ultimately, no association could be characterized between the polymorphism in IFN-γ + 874A/T and susceptibility to chronic HBV infection in this segment of the Iranian population (P > 0.05).

Association between IFN-γ genetic polymorphisms and susceptibility to hepatitis B virus infection: A meta-analysis

BACKGROUND

Hepatitis B virus (HBV) infection has become a global health burden because of its contagious mode of transmission and the resultant long-term liver damage.

AIM

To investigate how the polymorphisms of the IFN-γ gene, particularly the IFN-γ +874T/A (rs2430561) single nucleotide polymorphism (SNP), influence susceptibility to HBV infection.

SUBJECTS AND METHODS

Relevant articles were identified by a comprehensive literature search covering the following computerised bibliographic databases. Eleven independent case-control studies were ultimately selected for the current meta-analysis, comprising a total of 1527 HBV cases and 1467 healthy subjects.

RESULTS

The results in the current meta-analysis showed that carriers of the IFN-γ A allele were more likely to develop HBV infection than those without in all five genetic models (all p < 0.05). According to the ethnicity-based sub-group analysis, a significant difference of the IFN-γ rs2430561 T > A polymorphism was detected associated with the increased risk of HBV infection in Asians and European-derived populations in the majority of the groups.

CONCLUSIONS

The results implicate a possible relationship between the IFN-γ rs2430561 T > A polymorphism and the risk of HBV infection. Therefore, IFN-γ genetic polymorphisms might be important in determining an individual's susceptibility to HBV infection.

The Impact of IFN-γ Gene Polymorphisms on Spontaneous Clearance of HCV Infection in Fars Province, Southern of Iran

BACKGROUND

Certain polymorphisms in cytokine genes such as IFN-γ may influence the outcome of hepatitis C virus (HCV) infection. Here the frequency of the genotype, allele, and haplotype of IFN-γ gene at some loci is investigated in HCV-infected patients.

METHODS

Totally 255 patients with chronic HCV infection and 44 spontaneously cleared individuals were included. The chronic or clearance states were confirmed using enzyme-linked immunosorbent assay (ELISA) and two different qualitative reverse transcriptase polymerase chain reaction (RT-PCR) techniques. IFN-γ gene polymorphisms were performed by PCR using sequence-specific primers and PCR-RLFP on extracted genomic DNA.

RESULTS

The frequency of GG genotype (P = 0.0001, OR: 5.69 and CI: 2.21-14.62) and allele (P = 0.0003, OR: 2.73 and CI: 1.54-4.83) of IFN-γ gene at +2109 locus was significantly higher in cases that spontaneously cleared the infection. Haplotype analysis showed the association of AG haplotype (P = 0.0046, OR = 6.14 and CI = 1.56-25) with spontaneous clearance of the infection.

CONCLUSION

Our finding indicated that individuals with GG genotype at +2109 loci of IFN-γ gene and also AG haplotype (A allele at +874 loci and G allele at +2109 loci) may clear HCV infection more frequently than those with AA and AG genotype at +2109 loci and AA, TA, and TG haplotype.

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.

Associations of IFN-γ rs2430561 T/A, IL28B rs12979860 C/T and ERα rs2077647 T/C polymorphisms with outcomes of hepatitis B virus infection: a meta-analysis

Several studies investigated associations of IFN-γ rs2430561 T/A, IL28B rs12979860 C/T and ERα rs2077647 T/C gene polymorphisms with outcomes of hepatitis B virus (HBV) infection, but the results were controversial. Therefore, we performed a meta-analysis of all published observational studies to address this inconsistency. Literature was searched in online database and a systematic review was conducted based on the search results. A total of 24 studies were included and dichotomous data were presented as odds ratio (OR) with a 95% confidence interval (CI). The rs2430561 T allele was associated with reduced persistent HBV infection risk (T vs. A: OR, 0.690; 95% CI, [0.490, 0.971]), while the rs2077647 T allele significantly increased the risk of persistent HBV infection (T vs. C: OR, 1.678; 95% CI, [1.212, 2.323]). Rs 2077647 CC might play a role in protecting individuals against HBV persistence (TT vs. CC: OR, 4.109; 95% CI, [2.609, 6.473]). Furthermore, carriers of the rs2430561 TT genotype were more likely to clear HBV spontaneously compared with those of the AA genotype (TT vs. AA: OR, 0.555; 95% CI, [0.359, 0.856]). For rs12979860 C/T polymorphism, no significant correlation with HBV infection outcomes was found. In subgroup analyses, the results were similar to those of overall analysis. However, for rs2077647 TT vs. TC+CC, significantly increased risks were observed in the Asian and hospital-based population, but not in the overall analysis. IFN-γ rs2430561 T/A and ERα rs2077647 T/C genetic polymorphisms were associated with outcomes of HBV infection, but no association was found between IL28B rs12979860 C/T and HBV infection.

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.

The Role of Interferon Gamma Gene Polymorphism (+874A/T, +2109A/G, and -183G/T) in Response to Treatment Among Hepatitis C Infected Patients in Fars Province, Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection as a worldwide health problem is associated with cirrhosis and hepatocellular carcinoma. With current treatment regimen, pegylated interferon (PEG-IFN) plus ribavirin, sustain virological response (SVR) is achieved in only 50% of infected individuals. In HCV infection, an inappropriate ratio of cytokines may affect the benefit of antiviral therapy. Given the polymorphisms in regulatory regions of cytokines genes may influence cytokines production.

OBJECTIVES

We aimed to investigate both the frequency of genotypes and alleles of interferon gamma (IFN-γ) gene at +874A/T, +2109A/G, and -183G/T loci in HCV-infected patients and their associations with response to therapy.

PATIENTS AND METHODS

A total of 158 patients were included and treated with PEG-IFN plus ribavirin. The presence of HCV infection in patients was confirmed by reverse transcription polymerase chain reaction, and genomic DNA was extracted from peripheral leukocytes using salting out method. IFN-γ gene polymorphisms were identified by polymerase chain reaction using sequence specific primers and restriction fragment length polymorphism analysis on genomic DNA.

RESULTS

Of 158 patients, 110 (69.5%) subjects achieved SVR and 48 (30.5%) subjects did not respond to therapy. The frequency of AA genotype (P = 0.001; OR: 11.2; CI: 2.26-63.21) and A allele (P = 0.01; OR: 3.23; CI: 1.23 8.56) of IFN-γ gene at +2109 locus were significantly different between the responder and non-responder subjects infected with genotype 1. Regardless of HCV genotype, the frequency of AG genotype was also higher in responder group than those who did not respond to therapy (P = 0.041; OR: 05.05; CI: 1.05-33.25)). In case of IFN-γ gene at +874 locus, there was no difference in genotypes and alleles frequencies between the responder and non-responder subjects infected with HCV genotypes 1 and 3. Haplotype analysis showed no association between haplotypes and response to therapy. All participants had G/T genotype at -183 locus.

CONCLUSIONS

Our findings indicate that heterogeneity at +2109 locus of IFN-γ gene but not at +874 locus could interfere with successful therapy in patients infected with HCV genotype 1.

Tripartite Motif-Containing 22 Gene -364T/C Polymorphism Associated With Hepatitis B Virus Infection in Chinese Han Population

BACKGROUND

Hepatitis B virus (HBV) infection significantly contributes to the onset of liver disease and hepatocellular carcinoma. Understanding the pathogenesis of HBV infection susceptibility could help us to control HBV infection effectively.

OBJECTIVES

This study investigated single nucleotide polymorphisms (SNPs) of the tripartite motif-containing 22 (TRIM22) gene associated with HBV infection outcome.

PATIENTS AND METHODS

A total of 765 Chinese Han subjects were enrolled: 293 patients were presented with chronic hepatitis B (CHB), 224 were asymptomatic HBV carriers, 248 had self-limited HBV infection, and all of them were recruited for TRIM22 SNPs genotyping. RING and SPRY domains of TRIM22 gene were DNA-sequenced, and HBV serum markers and HBV DNA were measured quantitatively in all subjects.

RESULTS

243 (31.76%) of 765 Chinese Han patients showed genetic variation in the TRIM22 gene. TRIM22 SNPs were mainly in RING area -364T/C site, accounting for 98.35% of the population. There were no significant differences (P > 0.05) in the RING domain -364T/C SNP and allele frequencies between patients with chronic hepatitis and asymptomatic HBV carriers. The CC genotype of TRIM22 gene RING domain -364T/C locus (rs10838543) was associated with chronic HBV infection (OR = 2.30, 95% CI = 1.24-3.97, P = 0.0012; OR = 2.26, 95% CI = 1.08-3.74, P = 0.002) and a mutant allele C carrier of the TRIM22 gene was associated with HBV chronic infection (OR = 1.97, 95% CI = 1.10-3.75, P = 0.0049; OR = 2.12, 95% CI = 1.17-3.89, P = 0.0038).

CONCLUSIONS

TRIM22 gene RING domain -364T/C polymorphism is associated with chronic HBV infection in Chinese Han population.

A candidate gene study for the association of host single nucleotide polymorphisms with liver cirrhosis risk in chinese hepatitis B patients

BACKGROUND AND AIMS

Recently, genetic association studies have linked a number of single nucleotide polymorphisms (SNPs) with liver fibrosis risk of hepatitis C. The present study was designed to validate the association of emerging SNPs with development of liver cirrhosis and chronicity in a Chinese population infected with hepatitis B virus (HBV).

METHODS

714 Chinese subjects with persistent HBV infection (429 with evident liver cirrhosis and 285 without cirrhosis clinically or pathologically) and 280 subjects with spontaneous HBV clearance were studied. Six SNPs in five candidate genes were detected with the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method. The distribution of each polymorphism was compared between the age-matched cirrhotic and noncirrhotic subjects, and between subjects with persistent infection and spontaneous HBV clearance.

RESULTS

The rs2679757 polymorphism of antizyme inhibitor 1 (AZIN1) gene was associated with the risk of cirrhosis (odds ratio [OR] for GG+AG versus AA=1.47, 95% confidence interval [CI]=1.08-2.01, p=0.01). So was rs886277 in the transient receptor potential cation channel subfamily M, member 5 (TRPM5) gene (OR for CC versus CT+TT=1.63, 95% CI=1.20-2.22, p=0.002). The frequencies of these two SNPs were also associated with the severity of decompensated cirrhosis based on the Child-Pugh classification. Genotype frequencies of other SNPs were not different between the cirrhotic and noncirrhotic groups. No SNPs were associated with the outcome of spontaneous HBV clearance.

CONCLUSIONS

AZIN1 rs2679757 and TRPM5 rs886277 are associated with the risk of HBV-related liver cirrhosis in Chinese. The emerging SNPs warrant further clinical validation in other cohorts or ethnic groups, and could lead to mechanistic studies to reveal their contributions to fibrosis progression.

Cytokine Polymorphisms, Their Influence and Levels in Brazilian Patients with Pulmonary Tuberculosis during Antituberculosis Treatment

Cytokines play an essential role during active tuberculosis disease and cytokine genes have been described in association with altered cytokine levels. Therefore, the aim of this study was to verify if IFNG, IL12B, TNF, IL17A, IL10, and TGFB1 gene polymorphisms influence the immune response of Brazilian patients with pulmonary tuberculosis (PTB) at different time points of antituberculosis treatment (T1, T2, and T3). Our results showed the following associations: IFNG +874 T allele and IFNG +2109 A allele with higher IFN-γ levels; IL12B +1188 C allele with higher IL-12 levels; TNF −308 A allele with higher TNF-α plasma levels in controls and mRNA levels in PTB patients at T1; IL17A A allele at rs7747909 with higher IL-17 levels; IL10 −819 T allele with higher IL-10 levels; and TGFB1 +29 CC genotype higher TGF-β plasma levels in PTB patients at T2. The present study suggests that IFNG +874T/A, IFNG +2109A/G, IL12B +1188A/C, IL10 −819C/T, and TGFB1 +21C/T are associated with differential cytokine levels in pulmonary tuberculosis patients and may play a role in the initiation and maintenance of acquired cellular immunity to tuberculosis and in the outcome of the active disease while on antituberculosis treatment.

Association of cytokine gene polymorphisms and serum concentrations with the outcome of chronic hepatitis B

OBJECTIVE

The present paper investigated possible correlations between the clinical presentation of hepatitis B and the TNF-α -308G/A, IFN-γ +874A/T, TGF-beta1 -509C/T, and IL-10 -1081A/G polymorphisms and associated serum levels of these cytokines.

METHODS

Fifty-three hepatitis patients were selected and divided into two groups: A - inactive (n=30) and B - chronic hepatitis/cirrhosis (n=23). The control group consisted of 100 subjects who were positive for anti-HBc and anti-HBs. The serum concentrations of the cytokines were determined by immunoenzymatic assays. The polymorphisms of the cytokines genes were assessed by PCR and PCR-SSP.

RESULTS

The mean serum levels of IFN-γ of the control group were significantly higher than those of groups A and B, whereas the mean levels TGF-beta1 were significantly higher in groups A and B in comparison with the control. In the case of IL-10, the mean serum level recorded in the control group was significantly higher than that of group B. The TNF-α -308AG genotype was considerably more frequent in group B (43.3%) than the control (14.4%).

CONCLUSION

Higher serum levels of IFN-γ and TGF-beta1 were associated with chronic hepatitis B, and lower serum levels of IL-10 were found in patients with the active disease. Furthermore the presence of allele A of the TNF-α -308 polymorphism suggest a risk of the progressive disease.

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.

JAK1 gene polymorphisms are associated with the outcomes of hepatitis B virus infection, but not with α interferon therapy response in a Han Chinese population

AIMS

Janus kinase 1 (JAK1) is a key member in the interferon (IFN) signaling pathway. Recent studies suggested single-nucleotide polymorphisms (SNPs) in IFN pathway genes are associated with outcomes of hepatitis B virus (HBV) infection and response to IFNα therapy. The aim of the study is to investigate whether SNPs in JAK1 were associated with outcomes of HBV infection and response to IFNα therapy.

METHODS

We enrolled 395 chronic hepatitis B (CHB) patients and 251 subjects with the inactive carrier state, and 256 CHB patients who received IFNα treatment, with therapy efficacy evaluated. Twelve SNPs: rs310227, rs7531799, rs7546545, rs17127174, rs3790541, rs10493373, rs2780898, rs310247, rs310196, rs2780895, rs4244165, and rs17127024 in JAK1, which could represent all SNPs with minor allele frequency >0.2 recorded in the HapMap database were genotyped using a polymerase chain reaction-restriction fragment length polymorphism protocol and the TaqMan method.

RESULTS

SNP rs17127024 was associated with outcomes of HBV infection in an allele frequency (p=0.014) and genotype distributions (p=0.031), while SNP rs4244165 was associated with outcomes of HBV infection only in genotype distributions (p=0.008). There were no significant differences in allele frequencies and genotype distributions of these SNPs between the response group and the nonresponse group to IFNα therapy.

CONCLUSIONS

SNPs rs4244165 and rs17127024 in JAK1 were associated with outcomes of HBV infection, but not with response to IFNα therapy.

Expression and gene polymorphisms of interleukin 28B and hepatitis B virus infection in a Chinese Han population

BACKGROUND

Recent genome-wide association studies found that genetic polymorphisms near the IL28B gene is strongly associated with sustained viral response and spontaneous viral clearance in chronically infected hepatitis C patients.

AIMS

We aimed to evaluate the effects of IL28B variations on hepatitis B virus (HBV) infection in a Chinese Han population and to explore the association between IL28B polymorphisms and susceptibility to infection, viral clearance, disease progression, viral load and liver inflammation.

METHODS

We determined three IL28B single gene polymorphisms (rs12979860, rs12980275 and rs8099917) in 203 individuals with chronic HBV infection, 203 individuals with self-limited HBV infection and 203 individuals negative for all HBV seromarkers. Interleukin (IL)28B serum levels were evaluated in all subjects. Additionally, peripheral blood mononuclear cells from 42 chronically HBV-infected individuals were subjected to whole-genome expression studies.

RESULTS

The association among genotype, allele and haplotype frequencies of IL28B with alanine aminotransferase levels and HBV DNA was established. However, no significant differences were observed in genotype or allele frequencies among chronically HBV-infected, self-limited and healthy subjects. The serum IL28B level was lower in patients with chronic HBV infection than in the self-limited HBV-infected or healthy subjects. The serum IL28B level was correlated with the subject's genotype. Gene expression micro-array analysis showed enhanced IL28B expression in patients with low HBV viral load.

CONCLUSIONS

Variability at the IL28B locus is associated with HBV viral load and hepatic inflammation. Genetic variation of IL28B may prevent HBV progression by reducing viral load and liver inflammation, providing a valuable gene therapy tool.

Non-association of IL-12 +1188 and IFN-γ +874 polymorphisms with cytokines serum level in occult HBV infected patients

BACKGROUND/AIM

Occult hepatitis B infection (OBI) is identified as a form of hepatitis in which despite the absence of detectable HBsAg, HBV-DNA is observed in peripheral blood of patients. The main aim of this study has been to investigate the association between polymorphisms in +874 of IFN-γ and +1188 of IL-12 with their serum level in patients suffering from OBI.

MATERIALS AND METHODS

In this experimental study, plasma samples of 3700 blood donors were tested for the presence of hepatitis B surface antigen (HBsAg) and anti-HBc by ELISA. The HBsAg-/anti-HBc+ samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases and ARMS-PCR techniques were performed to examine the two known polymorphisms within IL-12 and IFN-γ. In addition, the serum levels of IL-12 and IFN-γ were also determined by ELISA.

RESULTS

Results of this study demonstrated that, 352 (9.5%) out of 3700 blood samples were HBsAg-/anti-HBc+ and HBV-DNA was detected in 57/352 (16.1%) of HBsAg-/anti-HBc+ samples. Our results showed that groups showed significant difference in CC allele of +1188 region of IL-12 and no difference was observed in the other evaluated genes. Our results also showed that the alleles of +1188 region of IL-12 and alleles of +874 of IFN-γ were also not associated with serum level of cytokines.

CONCLUSION

According to the results of this study, it may be concluded that the polymorphisms in +1188 region of IL-12 and +874 region of IFN-γ would not affect the expression of both cytokines at serum level in OBI patients.

Hepatitis B virus acquisition and pathogenesis in childhood: host genetic determinants

The clinical course of hepatitis B virus (HBV) infection varies from spontaneous recovery to chronic persistent infection leading to severe liver injury. Mounting evidence has recently highlighted the influence of host genotype in the complex interplay between viral and host factors. Studies in adults have suggested the existence of a genetic predisposition to HBV infection secondary to certain defects in the host response. These defects include opsonic deficiency, compromised antigen processing and presentation by human leucocyte antigen variations, attenuated T- and B-cell response, impaired cytokine and chemokine release, and production of receptors for several pertinent factors such as vitamin D and estrogen. By contrast, little is known about the genetic factors involved in the susceptibility to HBV transmission in early childhood. Herein, we review the literature regarding the association between host genetics and susceptibility to primary HBV infection, and we discuss the prospects of investigation in this field. A better understanding of HBV infection immunopathogenesis in the critical period of infancy may allow the development of optimal and innovative prevention and treatment.

Viral hepatitis: human genes that limit infection

Treatment response and susceptibility to chronic viral hepatitis C and B may be modified by host genetic factors. The majority of genetic variants that confer a significant risk have been localized in genes involved in immune response. However, many findings could not be replicated and almost none of the identified risk factors had a noticeable impact on clinical decisions. In contrast, recent findings in independent large genome wide association studies confirmed genetic variants in the interferon gamma gene locus as strong predictors of outcome with outstanding clinical relevance. This review gives an overview on significant genetic susceptibility factors for susceptibility and treatment outcome in chronic viral hepatitis C and B that have been identified by the classical candidate gene approach and genome wide studies and also highlights some recent findings on genetic factors for common adverse drug reactions.

IFNG +874 T>A single nucleotide polymorphism is associated with leprosy among Brazilians

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, a low virulence mycobacterium, and the outcome of disease is dependent on the host genetics for either susceptibility per se or severity. The IFNG gene codes for interferon-γ (IFN-γ), a cytokine that plays a key role in host defense against intracellular pathogens. Indeed, single nucleotide polymorphisms (SNPs) in IFNG have been evaluated in several genetic epidemiological studies, and the SNP +874T>A, the +874T allele, more specifically, has been associated with protection against infectious diseases, especially tuberculosis. Here, we evaluated the association of the IFNG locus with leprosy enrolling 2,125 Brazilian subjects. First, we conducted a case-control study with subjects recruited from the state of São Paulo, using the +874 T>A (rs2430561), +2109 A>G (rs1861494) and rs2069727 SNPs. Then, a second study including 1,370 individuals from Rio de Janeiro was conducted. Results of the case-control studies have shown a protective effect for +874T carriers (OR(adjusted) = 0.75; p = 0.005 for both studies combined), which was corroborated when these studies were compared with literature data. No association was found between the SNP +874T>A and the quantitative Mitsuda response. Nevertheless, the spontaneous IFN-γ release by peripheral blood mononuclear cells was higher among +874T carriers. The results shown here along with a previously reported meta-analysis of tuberculosis studies indicate that the SNP +874T>A plays a role in resistance to mycobacterial diseases.

Polymorphisms of some cytokines and chronic hepatitis B and C virus infection

AIM: To study the relationship between the polymorphisms in some cytokines and the outcome of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection.

METHODS: Samples were obtained from 203 patients infected with HBV and/or HCV while donating plasma in 1987, and 74 controls were obtained from a rural area of North China. Antibodies to HBV or HCV antigens were detected by enzyme-linked immunoassay. The presence of viral particles in the serum was determined by nested reverse-transcriptase polymerase chain reaction (PCR). Hepatocellular injury, as revealed by alanine aminotransferase (ALT) and aspartate aminotransferase level, was detected by a Beckman LX-20 analyzer. DNA was extracted from blood cells. Then, the single nucleotide polymorphisms of IL-2-330, IFN-γ+874, IL-10-1082/-592 and IL-4-589 were investigated by restriction fragment length polymorphism-PCR or sequence specific primer-PCR.

RESULTS: Persistent infection with HBV, HCV, and HBV/HCV coinfection was associated with IL-2-330 TT genotype and T allele, IFN-γ+874 AA genotype, and IL-10-1082 AA genotype. The clinical outcome of HBV and/or HCV infection was associated with IL-2-330 TT genotype and T allele, IFN-γ+874 AA genotype, and IL-10-1082 AA genotype. IL-2-330 GG genotype frequency showed a negative correlation with clinical progression, IL-10-1082 AA genotype frequency showed a positive correlation and IL-10-1082 AG genotype frequency showed a negative correlation with clinical progression. HCV RNA positive expression was associated with IL-10-1082 AA genotype and the A allele frequency. Abnormal serum ALT level was associated with IL-10-592 AC genotype frequency and IL-4-589 CC genotype, CT genotype, and the C allele.

CONCLUSION: These results suggest that polymorphisms in some cytokine genes influence persistent HBV and HCV infection, clinical outcome, HCV replication, and liver damage.

The haplotype of the MxA gene promoter is associated with hepatitis B virus infection in a Chinese population

BACKGROUND/AIM

The Myxovirus resistance protein A gene (MxA) is a key component of the innate antiviral response and has previously been shown to inhibit several viruses. This study was designed to assess whether the haplotype in the MxA promoter region was associated with hepatitis B virus (HBV) infection in a Chinese population.

METHODS

Three hundred and twelve HBV-infected patients and 317 healthy volunteers were enrolled in this study. Two polymorphisms of -88 and -123 located in the MxA gene promoter were identified by the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

The individual possessing haplotype GA, which was constructed by the two polymorphisms of -88G and -123A in the MxA gene promoter, was significantly associated with HBV infection [possessing one copy odds ratio (OR)=1.69, 95% confidence interval (CI) 1.21-2.35; two copy OR=2.84, 95% CI 1.12-7.21 respectively].

CONCLUSIONS

This case-control study suggested that the haplotype GA in the MxA gene promoter region would increase the susceptibility to HBV infection in a Chinese population.

A regulatory polymorphism in interferon-gamma receptor 1 promoter is associated with the susceptibility to chronic hepatitis B virus infection

The antiviral cascade triggered by interferon-gamma (IFN-gamma) represents a vital event for eradicating hepatitis B virus (HBV) in experimental animals. IFN-gamma signaling is mediated through the ligand binding to IFN-gamma receptor 1 (IFNGR1). Control of IFNGR1 expression level is one of the mechanisms by which cells modulate the potency of IFN-gamma signaling. In this study, we comprehensively investigated the single nucleotide polymorphisms (SNPs) in IFNGR1 gene and correlated their occurrence to susceptibility to HBV infection in a Chinese population. A total of 983 participants, including 361 chronic hepatitis B patients, 256 individuals who had spontaneously recovered from HBV infection, and 366 healthy control subjects, were enrolled in the study. Polymerase chain reaction-restriction fragment length polymorphism was used to identify seven SNPs (-611A/G, -56C/T, 40G/A, 95C/T, 130A/G, 20685A/G, 21227T/C) in IFNGR1 gene. We found that -56C and -56T allele were associated with viral clearance and viral persistence, respectively (P = 0.014). In a reporter-driven assay, we validated that the promoter variant with -56C exhibited a higher transcription level than that with -56T in HepG2 cells in a cell-type-specific pattern. We conclude that a functional -56C/T SNP in IFNGR1 promoter is associated with the clinical outcome of HBV infection in this Chinese population.