Association of HLA and TNF polymorphisms with the outcome of HBV infection in the South Indian population. Genes Immun. 2011;12:552-558. [PMID: 21593777 DOI: 10.1038/gene.2011.32]

Differential epitope prediction across diverse circulating variants of SARS-COV-2 in Brazil

COVID-19, caused by the SARS-COV-2 virus, induces numerous immunological reactions linked to the severity of the clinical condition of those infected. The surface Spike protein (S protein) present in Sars-CoV-2 is responsible for the infection of host cells. This protein presents a high rate of mutations, which can increase virus transmissibility, infectivity, and immune evasion. Therefore, we propose to evaluate, using immunoinformatic techniques, the predicted epitopes for the S protein of seven variants of Sars-CoV-2. MHC class I and II epitopes were predicted and further assessed for their immunogenicity, interferon-gamma (IFN-γ) inducing capacity, and antigenicity. For B cells, linear and structural epitopes were predicted. For class I MHC epitopes, 40 epitopes were found for the clades of Wuhan, Clade 2, Clade 3, and 20AEU.1, Gamma, and Delta, in addition to 38 epitopes for Alpha and 44 for Omicron. For MHC II, there were differentially predicted epitopes for all variants and eight equally predicted epitopes. These were evaluated for differences in the MHC II alleles to which they would bind. Regarding B cell epitopes, 16 were found in the Wuhan variant, 14 in 22AEU.1 and in Clade 3, 15 in Clade 2, 11 in Alpha and Delta, 13 in Gamma, and 9 in Omicron. When compared, there was a reduction in the number of predicted epitopes concerning the Spike protein, mainly in the Delta and Omicron variants. These findings corroborate the need for updates seen today in bivalent mRNA vaccines against COVID-19 to promote a targeted immune response to the main circulating variant, Omicron, leading to more robust protection against this virus and avoiding cases of reinfection. When analyzing the specific epitopes for the RBD region of the spike protein, the Omicron variant did not present a B lymphocyte epitope from position 390, whereas the epitope at position 493 for MHC was predicted only for the Alpha, Gamma, and Omicron variants.

Association between the HLA-DQB1 Gene Polymorphism and Chronic Progression of Hepatitis B in Indonesia

BACKGROUND: The progression of hepatitis B is affected by the activity of T lymphocytes. Activation of T lymphocytes requires a primary signal originating from the presentation of antigen by HLA molecules to T cell receptors. HLA-DQB1 gene polymorphisms can affect the ability of HLA to bind and present viral antigens to T cells, thus affecting T cell activation and potentially associated with the progression of chronic hepatitis B. AIM: We aimed to investigate the polymorphisms of the HLA-DQB1 gene and its influence on chronic hepatitis B progression of chronic hepatitis B patients in Indonesia. METHODS: This cross-sectional research studied chronic hepatitis B patients at the Internal Medicine Department, Arifin Ahmad Hospital, Pekanbaru, from January 2018 to December 2018. Subjects were grouped into three categories: (1) Inactive chronic hepatitis B, (2) active chronic hepatitis B, and (3) end stage liver disease (ESLD) which consisted of patients with liver cirrhosis and hepatocellular carcinoma. Examination of the HLA-DQB1 gene polymorphism was performed with the SSP-PCR method and sequenced to verify the PCR results. Analysis results of p < 0.05 were considered statistically significant. RESULTS: The most common allele in patients with chronic hepatitis B was the HLA-DQB1 0301. The HLA-DQB1 0301 allele found primarily in the inactive chronic hepatitis B group. The DQB1 0501 allele found to be more abundant in patients with active chronic hepatitis B. The HLA DQB1 0502 allele only found in patients with chronic hepatitis B with ESLD. CONCLUSIONS: The HLA-DQB1 gene polymorphism is associated with the progression of chronic hepatitis B in chronic hepatitis B patients in Indonesia.

Association of single nucleotide polymorphisms in immune-related genes with spontaneous HBsAg seroconversion: A systematic review and meta-analysis

BACKGROUND

Studies have reported that the immune system modulation genes are involved in the seroconversion during hepatitis B virus (HBV) infection. Here, a systematic review with meta-analysis is implemented on the association of polymorphisms in immune-related genes with the spontaneous hepatitis B surface antigen (HBsAg) seroconversion.

METHODS

A systematic literature search was conducted in the main electronic databases of Scopus, PubMed, and Web of Science before May 2022. Pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were used to evaluate the strength of the association between genetic polymorphisms and the chance of spontaneous HBsAg seroconversion.

RESULTS

A total of 40 studies finally included for meta-analysis of 2 HLA-DP SNPs, 2 HLA-DQ SNPs, 3 IFNL3/4 SNPs, 2 IL10 SNPs, and 5 TNF SNPs. Based on the overall pooled analysis, HLA-DP rs3077 A (OR = 1.47, 95%CI: 1.32-1.65), HLA-DP rs9277535 A (OR = 1.48, 95%CI: 1.32-1.66), HLA-DQ rs2856718 G (OR = 1.37, 95%CI: 1.18-1.59), HLA-DQ rs7453920 A (OR = 1.41, 95%CI: 1.04-1.93), IFNL3/4 rs12980275 G (OR = 1.26, 95%CI: 1.01-1.58), TNFA rs1799964 T (OR = 1.17, 95%CI: 1.02-1.35), and TNFA rs1800630 C (OR = 1.26, 95%CI: 1.03-1.55) increased significantly the chance of spontaneous HBsAg seroconversion.

CONCLUSION

This meta-analysis showed that the HLA-DP gene rs3077 and rs9277535 SNPs, HLA-DQ gene rs2856718 and rs7453920 SNPs, IFNL3/4 gene rs12980275 SNP, TNFA gene rs1799964 and rs1800630 SNPs are involved in the spontaneous HBsAg seroconversion.

HLA-II Alleles Influence Physical and Behavioral Responses to a Whey Allergen in a Transgenic Mouse Model of Cow's Milk Allergy

The symptoms of food allergies vary significantly between individuals, likely due to genetic determinants. In humans, allergy development is initiated by antigen-presenting cells via class II human leukocyte antigen (HLA-II). The HLA-II gene is highly polymorphic, and its allelic variance is thought to influence the susceptibility of individuals to a particular allergen. However, whether antigen presentation by different HLA-II variants contributes to symptom variation is not clear. We hypothesized that HLA-II allelic variance affects symptom phenotypes, including immediate physical reactions and delayed behavioral changes, in individuals with food hypersensitivity. To test our hypothesis, male and female mice of three transgenic strains expressing an HLA-II variant, DR3, DR15, or DQ8, were used to establish a cow's milk allergy model. Mice were sensitized to a bovine whey allergen, β-lactoglobulin (BLG; Bos d 5), weekly for 5 weeks, followed by an acute oral allergen challenge. At 30 min post-challenge, BLG-sensitized DR3 mice showed moderate to severe anaphylaxis resulting in perioral redness, swelling, and death. In contrast, DQ8 and DR15 mice were generally asymptomatic. The production of allergen-specific immunoglobulins was also HLA- and sex-dependent. Both male and female DR3 and female DR15 mice significantly increased BLG-specific IgE production, while robust elevation in BLG-specific IgG1 was observed in sensitized DQ8 mice of both sexes and, to a lesser extent, in DR15 males. Furthermore, BLG-sensitized DR15 mice showed sex-specific behavior changes, with males exhibiting mobility changes and anxiety-like behavior and females showing spatial memory impairment. When splenocytes from transgenic mice were stimulated in vitro with BLG, phenotypes of immune cells were HLA- and sex-specific, further underscoring the influence of HLA-II on immune responses. Our results support that HLA-II alleles influence behavioral responses in addition to immune and physical reactions of food allergy, suggesting that certain HLA-II variants may predispose individuals to food-allergy-associated behavioral changes.

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.

Synergetic Interaction of HLA-DRB1*07 Allele and TNF-Alpha - 863 C/A Single Nucleotide Polymorphism in the Susceptibility to Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease which is characterized by dysregulation of various cytokines propagating the inflammatory processes that is responsible for tissue damage. Tumor necrosis factor alpha (TNF-α) is one of the most important immunoregulatory cytokines that has been implicated in the different autoimmune diseases including SLE. Two hundred and two patients with SLE and 318 controls were included in the study. The TNF-α gene promoter region (from - 250 to - 1000 base pairs) was analyzed by direct Sanger's DNA sequencing method to find promoter variants associated with South Indian SLE patients. We have analyzed six TNF-α genetic polymorphisms including, - 863C/A (rs1800630), - 857C/T (rs1799724), - 806C/T (rs4248158), - 646G/A (rs4248160), - 572A/C (rs4248161) and - 308G/A (rs1800629) in both SLE patients and controls. We did not find association of TNF-α gene promoter SNPs with SLE patients. However, the - 863A (rs1800630) allele showed association with lupus nephritis phenotype in patients with SLE (OR: 1.62, 95%CI 1.04-2.53, P = 0.034). We found serum TNF-α level was significantly elevated in SLE cases as compared to control and found no association with any of the polymorphisms. The haplotype analysis revealed a significant protective association between the wild TNF-α alleles at positions - 863C, - 857C, - 806C, - 646G, - 572A and - 308G (CCCGAG) haplotype with lupus nephritis phenotype (OR 0.53, 95% CI 0.35-0.82, P = 0.004). Additionally, the TNF-α - 863 C/A (rs1800630) polymorphism and HLA-DRB1*07 haplotype showed significant differences between SLE patients and controls (OR 4.79, 95% CI 1.73-13.29, P = 0.0009). In conclusion, TNF-α - 863A allele (rs1800630) polymorphism is associated with increased risk of nephritis in South Indian SLE patients. We also found an interaction between HLA-DRB1*07 allele with TNF-α - 863 C/A promoter polymorphism giving supportive evidence for the tight linkage disequilibrium between TNF-α promoter SNPs and MHC class II DRB1 alleles.

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.

HLA-DQA1 & DQB1 variants associated with hepatitis B virus-related chronic hepatitis, cirrhosis & hepatocellular carcinoma

Background & objectives:

Clinical outcome after hepatitis B virus (HBV) exposure varies extremely from spontaneous clearance to chronic hepatitis B and often progresses to liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Host genetic factor plays an important role in the regulation of immune response. This study was aimed to investigate whether HLA class II DQA1 and DQB1 gene polymorphism were associated with chronic hepatitis B infection and in the development of HBV-related LC and HCC.

Methods:

DQA1 and DQB1 allele polymorphism were studied in 187 patients with HBV-related liver diseases (which included 73 chronic hepatitis B, 84 LC and 30 HCC patients) and 109 controls who had spontaneously recovered from HBV infection using polymerase chain reaction amplification with sequence-specific primers.

Results:

Our data suggested that DQA1*0101/2/4 [odds ratio (OR)=2.78; P^c=0.003], DQA1*0103 (OR=2.64; P^c=0.0007) and DQB1*0302/3 (OR=2.15; P^c=0.01) were associated with the protection from chronic HBV infection, whereas DQB1*0402 (OR=0.25; P^c=0.001) showed susceptible effect on chronic HBV infection. DQB1*0601 (OR=3.73; P^c=0.006) conferred protective effect from developing LC; similarly, DQB1*0302/3 (OR=5.53; P^c=0.05) and DQB1*0402 (OR=0.00; P^c=0.001) conferred protective effect from developing HCC. However, DQA1*0601 and DQB1*0503 showed susceptible effect on chronic HBV infection; these associations were no longer significant after Bonferroni correction.

Interpretation & conclusions:

Our results revealed HLA-DQA1*0101/2/4 - DQA1*0103 - DQB1*0302/3 and DQB1*0601 as protective and DQB1*0402 as risk alleles. The study suggests that various subtypes of HLA-DQA1 and DQB1 are associated with both HBV clearance and development of chronic HBV infections.

Virological and Clinical Characteristics of Hepatitis B Virus Genotype A

Hepatitis B virus (HBV) infection is one of the most prevalent chronic viral infections in humans. The overall prevalence of hepatitis B surface antigen (HBsAg) is reported to be 3.6%; however, it varies depending upon the geographic area. HBV is classified into ten genotypes (A through J) on the basis of an intergroup genomic divergence of > 8%. Specifically, HBV genotype A exhibits several unique virological and clinical characteristics and can be further classified into seven subtypes. Among them, subtype A2 or Ae (A2/[e]) is occasionally responsible for nosocomial infection and among homosexual males. Regarding virological factors, the G1896A precore mutation is rarely observed in genotype A as it would disrupt an essential stem-loop structure in the ε signal essential for pregenomic RNA packaging. HBV genotype A also harbors a 6-nucleotide C-terminal insertion in the hepatitis B-e antigen (HBeAg) precursor, resulting in a variable-length HBeAg protein product observed in serum of positive patients. These molecular traits likely contribute to the specific clinical presentation of genotype A-infected patients, such as mild acute hepatitis B (AHB), longer persistence of HBsAg positivity in AHB, and increased chronicity after AHB in adults. However, genotype A shows a better response to interferon than other genotypes in chronic hepatitis B patients. Here, we review the virological and clinical characteristics of HBV genotype A that will be useful in elucidating the association among persistent viral infection, host genetic factors, and treatment in future studies.

Association of TNF-Alpha gene polymorphisms and susceptibility to hepatitis B virus infection in Egyptians

Tumor necrosis factor alpha (TNF-α) is one of the important cytokine in generating an immune response against hepatitis B virus (HBV). Genetic polymorphisms might influence gene transcription, leading to disturbance in cytokine production. We hypothesized that single nucleotide polymorphism (SNPs) in TNF-α gene could affect the pathogenesis of HBV. To test this hypothesis, we investigated the role of TNF-α polymorphism [-863C/A (rs1800630), -308G/A (rs1800629), -376G/A (rs1800750), -857C/T (rs1799724) and +489G/A (rs1800610)] in the susceptibility to chronic hepatitis B (CHB) infection. Polymorphisms of the TNF-α (-863C/A (rs1800630), -308G/A) were analyzed by Polymerase chain reaction sequence specific primer (PCR-SSP) while TNF-α (-376G/A, -857C/T and +489G/A) by PCR-restriction fragment length polymorphism (PCR-RFLP) in 104 patients with CHB and 104 healthy controls. The plasma level of TNF-α was measured using Enzyme-linked immunosorbent assay (ELISA). The study showed a significant increase in the frequency of -863CC, -376GA, -857CC, -857TT and +489GA genotypes and -863C, -376A, -857C, and +489A alleles in CHB patients compared to controls. In addition, CAGCG haplotype had a highest frequency in CHB patients. A strong Linkage Disequilibrium (LD) between TNF-α -863C/A (rs1800630) and -376G/A (D' = 0.7888, r² = 0.0200); -308G/A and -857C/T (D' = 0.9213, r² = 0.1770); -308G/A and +489G/A (D' = 0.9088, r² = 0.1576) was demonstrated. CHB patients had significantly lower levels of TNF-α compared to controls. In conclusion, our preliminary results suggest that -863C/A (rs1800630), -308G/A, -376G/A, and +489G/A of the TNF-α gene may play a role in HBV susceptibility in Egyptians. The significant reduction in TNF-α in CHB patient was independent of any particular genotype/haplotype in TNF-α.

Cytokine-Mediated Immunopathogenesis of Hepatitis B Virus Infections

Hepatitis B virus (HBV) infection is a worldwide health problem, with approximately one third of populations have been infected, among which 3-5% of adults and more than 90% of children developed to chronic HBV infection. Host immune factors play essential roles in the outcome of HBV infection. Thus, ineffective immune response against HBV may result in persistent virus replications and liver necroinflammations, then lead to chronic HBV infection, liver cirrhosis, and even hepatocellular carcinoma. Cytokine balance was shown to be an important immune characteristic in the development and progression of hepatitis B, as well as in an effective antiviral immunity. Large numbers of cytokines are not only involved in the initiation and regulation of immune responses but also contributing directly or indirectly to the inhibition of virus replication. Besides, cytokines initiate downstream signaling pathway activities by binding to specific receptors expressed on the target cells and play important roles in the responses against viral infections and, therefore, might affect susceptibility to HBV and/or the natural course of the infection. Since cytokines are the primary causes of inflammation and mediates liver injury after HBV infection, we have discussed recent advances on the roles of various cytokines [including T helper type 1 cells (Th1), Th2, Th17, regulatory T cells (Treg)-related cytokines] in different phases of HBV infection and cytokine-related mechanisms for impaired viral control and liver damage during HBV infection. We then focus on experimental therapeutic applications of cytokines to gain a better understanding of this newly emerging aspect of disease pathogenesis.

Association of human leukocyte antigen haplotypes with clearance and persistence of hepatitis B virus infection in northeastern China

This study investigated clinical implications of human leukocyte antigen (HLA) I and II haplotypes, in combination with HBV sub-genotype C2, in hepatitis B virus (HBV) infections in northeastern China. Here, HLA haplotypes of 230 HBV-infected patients were compared to 210 healthy, unrelated Han individuals. Of the 230 HBV-infected patients, 54 had acute self-limited hepatitis (ASH) with sub-genotype C2 (ASH-C2), 144 had chronic hepatitis (CH) with sub-genotypes C2 and B2 (CH-C2 and CH-B2), and 32 spontaneously recovered without sub-genotype results. All groups underwent HLA typing and haplotype analysis. The results revealed that A*02-DRB1*12 and A*02-B*15-DRB1*09 carriers were susceptible to HBV infection. A*02-B*15-DRB1*09 is probably associated with acute onset and viral clearance and A*02-DRB1*12, with viral persistence. In HBV infections, B*40-DRB1*12 was associated with HBV persistence, whereas B*46-DRB1*09, A*24-DRB1*14, and B*15-DRB1*04 carriers easily recovered from the disease. By contrast, when infected with the HBV-C2 sub-genotype, A*24-DRB1*14, B*15-DRB1*04, A*02-B*15, A*02-DRB1*15, and A*02-B*15-DRB1*09 carriers displayed an acute clinical course before recovery. This study reveals a relationship between HLA haplotypes and HBV pathogenesis, thereby providing potential therapeutic targets to treat HBV infection.

Genetic variation in the lymphotoxin-α (LTA)/tumour necrosis factor-α (TNFα) locus as a risk factor for idiopathic achalasia

BACKGROUND

Idiopathic achalasia is a rare motor disorder of the oesophagus characterised by neuronal loss at the lower oesophageal sphincter. Achalasia is generally accepted as a multifactorial disorder with various genetic and environmental factors being risk-associated. Since genetic factors predisposing to achalasia have been poorly documented, we assessed whether single nucleotide polymorphisms (SNPs) in genes mediating immune response and neuronal function contribute to achalasia susceptibility.

METHODS

391 SNPs covering 190 immune and 67 neuronal genes were genotyped in an exploratory cohort from Central Europe (589 achalasia patients, 794 healthy volunteers (HVs)). 24 SNPs (p<0.05) were validated in an Italian (160 achalasia patients, 278 HVs) and Spanish cohort (281 achalasia patients, 296 HVs). 16 SNPs in linkage disequilibrium (LD) with rs1799724 (r(2)>0.2) were genotyped in the exploratory cohort. Genotype distributions of patients (1030) and HVs (1368) were compared using Cochran-Armitage trend test.

RESULTS

The rs1799724 SNP located between the lymphotoxin-α (LTA) and tumour necrosis factor-α (TNFα) genes was significantly associated with achalasia and withstood correction for testing multiple SNPs (p=1.17E-4, OR=1.41 (1.18 to 1.67)). SNPs in high LD with rs1799724 were associated with achalasia. Three SNPs located in myosin-5B, adrenergic receptor-β-2 and interleukin-13 (IL13) showed nominally significant association to achalasia that was strengthened by replication.

CONCLUSIONS

Our study provides evidence for rs1799724 at the LTA/TNFα locus as a susceptibility factor for idiopathic achalasia. Additional studies are needed to dissect which genetic variants in the LTA/TNFα locus are disease-causing and confirm other variants as potential susceptibility factors for achalasia.

Association of TNF-α Promoter Polymorphism with HBV Associated Disease Outcome Among HBV Infected Patients from Orissa, Southern Part of East India

BACKGROUND

TNF-α promoter polymorphism has been known to be a potential predictive factor in patients with HBV infection. We therefore tried to investigate whether the TNF-α promoter polymorphism at position -238, -857 and -863 was associated with the outcome of HBV infection in a population from Orissa, southern part of East India.

METHODS

A total of 195 patients recruited for the study were classified into 85 controls and 110 HBV infected cases, which included 34 IC, 30 CLD, 32 LC and 14 HCC patients. The polymorphisms at the respective sites were detected by a PCR-RFLP followed by statistical analysis.

RESULTS

The frequency of the genotype -238 GG and the allele -238G in the cases (89.0% and 92.7% respectively) was significantly higher than that in the controls (68.2% and 82.2% respectively) (P < 0.001, OR = 3.8 and P = 0.001, OR = 2.73). Whereas the -238 GA genotype was significantly high in the control group (28.2%) when compared to the cases (7.2%) (P < 0.001, OR = 0.2). Similarly, the frequency of -863CC and the allele -863C was significantly higher among the cases (24.5% and 49.5%) compared to controls (1.17% and 34.7%), (P < 0.001, OR = 27.32 and P = 0.003, OR = 1.85), whereas the -863CA genotype was significantly high in the controls (67.0%) when compared to the cases (50.0%) (P = 0.01, OR = 0.49). Haplotype -863C/-857C/-238G in cases was significantly higher than controls (P = 0.002). Multivariate logistic regression analysis indicates that the genotype -863CC bears a negative association with liver disease progression.

CONCLUSION

The present study established an association of polymorphisms at site -238 and -863 of the TNF-α promoter with the outcome HBV infection and disease progression.

Association of HLA alleles with the responsiveness to hepatitis B virus vaccination in Korean infants

Hepatitis B virus (HBV) vaccination is the most effective means of countering HBV-related morbidity and mortality, and individuals who do not respond to vaccination (non-responders) are problematic. The aim of the present study was to investigate associations between HLA and responsiveness to HBV vaccine in Korean infants. A total of 944 healthy Korean infants 9-12 months old were enrolled, and HLA distribution was compared among subgroups in accordance with the response to HBV vaccination. The HLA distribution of the subjects was similar to known Korean population data and did not deviate from the HWE proportions. The alleles that showed positive associations with non-responsiveness (<10mIU/mL) or low antibody titer (<100mIU/mL) were HLA-A*33, B62, DRB1*04, and DRB1*07, while the alleles A*02 and DRB1*08 showed negative associations. Among these alleles, B62, DRB1*07 and DRB1*08(-) showed significant associations with a poor or decreased response to vaccination even after correction (OR=1.83, 1.99, 5.63; pc<0.05) and also showed dose effects. After stratification by other associated alleles at different loci, B62 and DRB1*07 were independently associated with non-responsiveness, but A*02(-) and DRB1*08(-) lost their individual associations. The combined association of A*02(-)-DRB1*08(-) and B62-DRB1*08(-) was significant (OR=25.2 and 24.5; pc<0.05). Although the hierarchy is not clear, we can assume the following: (i) B62 and DRB1*07 have independent effects, (ii) DRB1*08(-) has a very strong and synergic effect, and (iii) there is probability of a third factor controlling A*02(-) and DRB1*08(-) with an effect on non-responsiveness to HBV vaccination in Korean infants.

Human genes involved in hepatitis B virus infection

Persistent hepatitis B virus (HBV) infection is a significant public health problem because it is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). Roughly one-third of the world population has been infected with HBV and there are about 350 million (5%-6%) persistent carriers. HBV causes 80% of all liver cancer cases and is the second most important carcinogen, after smoking tobacco. There is an approximate 90% risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30% risk in pre-school children. Only 5%-10% of adults become persistent carriers following infection. Of individuals persistently infected with HBV, 10%-30% will develop liver cirrhosis and HCC. These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological, viral or environmental factors. Thus, differences in host genetic factors may affect the natural history of hepatitis B.

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.

Systematic review with meta-analysis: do interferon lambda 3 polymorphisms predict the outcome of interferon-therapy in hepatitis B infection?

BACKGROUND

Interferon lambda 3 (IFN-λ3) polymorphisms are the strongest genetic predictor of outcome of hepatitis C virus infection and of response to Pegylated interferon (PegIFN)-based therapy. Whether this holds true for hepatitis B virus (HBV) infection is matter of controversy.

AIM

To review the association between host genomics and spontaneous or interferon-induced clearance of HBV with specific reference to the recently identified interleukin 28B gene now renamed IFN-λ3.

METHODS

A literature search was performed on MEDLINE, EMBASE and Web of Science for English articles and abstracts using free text words and combinations of the following terms 'IL28B', 'IFN lambda', 'genomics', 'hepatitis B virus', 'interferon' 'GWAS', 'treatment', 'SNPs', 'HLA', 'polymorphisms'.

RESULTS

Genome-wide association studies convincingly demonstrated an association between SNPs in the HLA locus and spontaneous resolution of HBV infection in subgroups of Asian patients, yet no information is available for Caucasians. The preliminary observations of an association between IFN-λ3 SNP and virological and serological responses to IFN in both HBeAg-positive and -negative patients could not be replicated by subsequent studies. Yet, majority of studies performed so far suffer several limitations in terms of sample size, selection of the patients, endpoints of therapy, treatment strategies and duration of follow-up.

CONCLUSIONS

While host genetics is associated with an increased likelihood of spontaneous clearance of HBV among genotype B/C patients, the relationship between IFN-λ3 polymorphisms and response to IFN has not been confirmed. Further studies in large cohorts of homogeneous patients are required, before this genetic test can be recommended in clinical practice.

Association of Interleukin-1β and Gene Polymorphisms with Liver Pathogenesis in Hepatitis B Virus Infection among Eastern Indian Population

BACKGROUND

Interleukin-1β (IL-1β) is an important member of the family of the proinflammatory cytokines that modulate outcome of hepatitis B virus (HBV) infection.

OBJECTIVES

This study was designed to investigate the relationship between the polymorphic genotypes of the interleukin-1β (IL-1β) promoter region and the interleukin-1 receptor antagonist gene (IL-1RN) and disease outcome in HBV-infected individuals.

METHODS

DNA was extracted from 395 study subjects including HBV carriers with varying clinical presentations, as well as healthy controls and spontaneously recovered cases (SRC). Polymorphisms in IL-1β (at position -511) and IL-1RN (variable nucleotide tandem repeats, VNTR) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR based assay respectively.

RESULTS

Among the study subjects, different IL-1β (at position -511) (CC, CT and TT) and IL-1RN (1/1, 1/2, 2/2 and 1/3) polymorphic genotypes were found at variable proportions. Logistic regression analysis revealed, no notable difference at the level of IL-1β promoter (P = 0.244; OR = 0.78; 95% CI = 0.52-1.18) or IL-1RN genotype polymorphism (P = 0.840; OR = 1.03; 95% CI = 0.78-1.36) among the HBV carriers and controls or SRC cases. Pairwise proportion testing showed, IL-1β -511 genotype CC was significantly higher among asymptomatic carriers (ASC) in comparison with liver cirrhosis (LC) patients (P value = 0.028) and healthy control group (P-value = 0.036). IL-1RN genotype 2/2 was considerably higher in LC group than SRC as well as control group. Combinations of IL-1β (-511) and IL-1RN polymorphisms were associated with disease progression, such as CC-1/2 with ASC and TT-2/2 with LC.

CONCLUSION

IL-1β polymorphisms are found to be associated with disease severity. Different polymorphic combinations are associated with degree of disease severity. Overall this is the first report from Eastern India, which shows association of IL-1β polymorphisms with HBV-related hepatic complications.

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.

Theoretical basis of a beneficial role for vitamin D in viral hepatitis

Abnormal bone metabolism and dysfunction of the calcium-parathyroid hormone-vitamin D axis have been reported in patients with viral hepatitis. Some studies suggested a relationship between vitamin D and viral hepatitis. Genetic studies have provided an opportunity to identify the proteins that link vitamin D to the pathology of viral hepatitis (i.e., the major histocompatibility complex class II molecules, the vitamin D receptor, cytochrome P₄₅₀, the renin-angiotensin system, apolipoprotein E, liver X receptor, toll-like receptor, and the proteins regulated by the Sp1 promoter gene). Vitamin D also exerts its effects on viral hepatitis via non-genomic factors, i.e., matrix metalloproteinase, endothelial vascular growth factor, prostaglandins, cyclooxygenase-2, and oxidative stress. In conclusion, vitamin D could have a beneficial role in viral hepatitis. Calcitriol is best used for viral hepatitis because it is the active form of the vitamin D₃ metabolite.

Association between HLA-DRB1*11/14 alleles and HBV-related liver diseases

AIM: To investigate the association between HLA-DRB1*11/14 alleles and hepatitis B virus (HBV)-related diseases in the Guangxi population.

METHODS: A total of 320 patients with HBV infection and 150 normal control subjects were included in this study. The frequencies of HLA-DRB1* 11/14 alleles were measured by polymerase chain reaction/sequence specific primer (PCR/SSP).

RESULTS: The frequency of the HLA-DRB1*11 allele in patients with liver cirrhosis was markedly higher than that in the normal control group (18.9% vs 7.3%, P = 0.007, OR = 0.340). The frequencies of the HLA-DRB1*14 allele in chronic asymptomatic hepatitis B virus carriers, patients with chronic hepatitis B, liver cirrhosis, or hepatocellular carcinoma were all higher than that in the normal control group (36.0% vs 19.3%, 30.7% vs 19.3%, 32.2% vs 19.3%, 35.0% vs 19.3%; P = 0.016, 0.025, 0.024, 0.035, OR = 0.426, 0.541, 0.504, 2.247).

CONCLUSION: The HLA-DRB1*11 allele is associated with susceptibility to liver cirrhosis, and the HLA-DRB1*14 allele is associated with susceptibility to chronic asymptomatic hepatitis B, chronic hepatitis B, liver cirrhosis and hepatocellular carcinoma in patients with HBV infection.

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.