A genome-wide association study with DNA pooling identifies the variant rs11866328 in the GRIN2A gene that affects disease progression of chronic HBV infection

TBX5 Variants are Associated with Susceptibility to and the Incidence of Liver Cirrhosis and Hepatocellular Carcinoma in the Chinese Population: A Multicenter and Follow-Up Study

Purpose

Liver cirrhosis (LC) and hepatocellular carcinoma (HCC) are progressions affected by genetic predispositions, and persistent hepatitis B virus infection also demonstrates genetic susceptibility. All HBV-related outcomes have been compared in parallel to identify risk polymorphism in HBV progression.

Methods

The multiple-stage association study filtered and validated the risk SNPs for HBV progression and explored their association with persistent infection, with a total of 8906 subjects in China from three sites. Cox proportional hazards models and Kaplan-Meier Log rank tests were used to determine the time to the progressive event in relation to the risk SNPs.

Results

Rs3825214 in TBX5 replicated a specific association with LC and HCC in 4 progression cohorts and was not related to persistent infection, naivety to HBV infection and natural clearance in 3 persistent cohorts. In combined samples, rs3825214 was associated with an increased risk of LC (P<0.001; OR = 1.98) and HCC (P<0.001; OR = 1.68). The results of bioinformatics analysis indicated that rs3825214 genotypes change RNA structure and intron excision ratio. In the follow-up of 571 hospital-based persistent HBV infection patients, ninety-three (16.29%) developed LC, and seventy-four (12.96%) progressed to HCC at a median follow-up of 5.1 years. Rs3825214 was associated with HCC and LC events in Cox proportional hazards models (P<0.001).

Conclusion

We identified and confirmed that genetic variants in TBX5 are significantly associated with susceptibility to and the incidence of LC and HCC.

Genome-wide copy number variation analysis of hepatitis B infection in a Japanese population

Genome-wide association studies have been performed to identify common genetic variants associated with hepatitis B (HB). However, little is known about copy number variations (CNVs) in HB. In this study, we performed a genome-wide CNV analysis between 1830 healthy controls and 1031 patients with HB infection after quality control. Using signal calling by the Axiom Analysis Suite and CNV detection by PennCNV software, we obtained a total of 4494 CNVs across all individuals. The genes with CNVs that were found only in the HB patients were associated with the immune system, such as antigen processing. A gene-level CNV association test revealed statistically significant CNVs in the contactin 6 (CNTN6) gene. Moreover, we also performed gene-level CNV association tests in disease subgroups, including hepatocellular carcinoma patients, liver cirrhosis patients, and HBV carriers, including asymptomatic carriers and patients with HBV-derived chronic hepatitis. Our findings from germline cells suggested that patient-specific CNVs may be inherent genetic risk factors for HB.

The risk of contracting the hepatitis B virus may be linked to the number of copies of certain genes in an individual’s genome. A Japanese team led by Masataka Kikuchi, Osaka University, and Akihiro Nakaya, University of Tokyo, looked for repeated segments of the genome, known as copy number variants (CNVs), that differed between people with hepatitis B infections and those without. Studying around 3000 individuals of Japanese descent, the researchers identified several rare CNVs associated with immune function in hepatitis-affected individuals. They also found a common CNV in a gene called CNTN6 that the hepatitis B virus often uses to integrate itself into the genome of liver cells, a process that can lead to cancer. The findings underscore the importance of CNVs as inherited risk factors for hepatitis B and other viral infections.

The interaction of DNA repair factors ASCC2 and ASCC3 is affected by somatic cancer mutations

The ASCC3 subunit of the activating signal co-integrator complex is a dual-cassette Ski2-like nucleic acid helicase that provides single-stranded DNA for alkylation damage repair by the α-ketoglutarate-dependent dioxygenase AlkBH3. Other ASCC components integrate ASCC3/AlkBH3 into a complex DNA repair pathway. We mapped and structurally analyzed interacting ASCC2 and ASCC3 regions. The ASCC3 fragment comprises a central helical domain and terminal, extended arms that clasp the compact ASCC2 unit. ASCC2–ASCC3 interfaces are evolutionarily highly conserved and comprise a large number of residues affected by somatic cancer mutations. We quantified contributions of protein regions to the ASCC2–ASCC3 interaction, observing that changes found in cancers lead to reduced ASCC2–ASCC3 affinity. Functional dissection of ASCC3 revealed similar organization and regulation as in the spliceosomal RNA helicase Brr2. Our results delineate functional regions in an important DNA repair complex and suggest possible molecular disease principles.

The DNA helicase ASCC3 is the largest subunit of the activating signal co-integrator complex (ASCC), and its DNA unwinding activity is required for the AlkBH3/ASCC-dependent DNA de-alkylation repair pathway. Here, the authors identify a minimal stable complex of the two ASCC subunits ASCC2 and ASCC3, determine the complex crystal structure and further show that cancer-related mutations at the interface between both proteins reduce ASCC2–ASCC3 affinity.

Advanced Therapeutics, Vaccinations, and Precision Medicine in the Treatment and Management of Chronic Hepatitis B Viral Infections; Where Are We and Where Are We Going?

The management of chronic hepatitis B virus (CHB) infection is an area of massive unmet clinical need worldwide. In spite of the development of powerful nucleoside/nucleotide analogue (NUC) drugs, and the widespread use of immune stimulators such as interferon-alpha (IFNα) or PEGylated interferon-alpha (PEG-IFNα), substantial improvements in CHB standards of care are still required. We believe that the future for CHB treatment now rests with advanced therapeutics, vaccination, and precision medicine, if all are to bring under control this most resilient of virus infections. In spite of a plethora of active drug treatments, anti-viral vaccinations and diagnostic techniques, the management of CHB infection remains unresolved. The reason for this is the very complexity of the virus replication cycle itself, giving rise to multiple potential targets for therapeutic intervention some of which remain very intractable indeed. Our review is focused on discussing the potential impact that advanced therapeutics, vaccinations and precision medicine could have on the future management of CHB infection. We demonstrate that advanced therapeutic approaches for the treatment of CHB, in the form of gene and immune therapies, together with modern vaccination strategies, are now emerging rapidly to tackle the limitations of current therapeutic approaches to CHB treatment in clinic. In addition, precision medicine approaches are now gathering pace too, starting with personalized medicine. On the basis of this, we argue that the time has now come to accelerate the design and creation of precision therapeutic approaches (PTAs) for CHB treatment that are based on advanced diagnostic tools and nanomedicine, and which could maximize CHB disease detection, treatment, and monitoring in ways that could genuinely eliminate CHB infection altogether.

Advances in the genome-wide association study of chronic hepatitis B susceptibility in Asian population

Chronic hepatitis B (CHB) is the most common chronic liver disease resulting from viral infection and has become a serious threat to human health. Each year, about 1.2 million people in the world die from diseases caused by chronic infection of hepatitis B virus. The genetic polymorphism is significantly associated with the susceptibility to chronic hepatitis B. Genome-wide association study was recently developed and has become an important tool to detect susceptibility genes of CHB. To date, a number of CHB-associated susceptibility loci and regions have been identified by scientists over the world. To clearly understand the role of susceptibility loci in the occurrence of CHB is important for the early diagnosis and prevention of CHB.

Genome-Wide Association Study Identifies a New Locus at 7q21.13 Associated with Hepatitis B Virus-Related Hepatocellular Carcinoma

Purpose: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. In China, chronic hepatitis B virus (HBV) infection remains the major risk factor for HCC. In this study, we performed a genome-wide association study (GWAS) among Chinese populations to identify novel genetic loci contributing to susceptibility to HBV-related HCC.Experimental Design: GWAS scan is performed in a collection of 205 HBV-related HCC trios (each trio includes an affected proband and his/her both parents), and 355 chronic HBV carriers with HCC (cases) and 360 chronic HBV carriers without HCC (controls), followed by two rounds of replication studies totally consisting of 3,796 cases and 2,544 controls.Results: We identified a novel association signal within the CDK14 gene at 7q21.13 (index rs10272859, OR = 1.28, P = 9.46 × 10^-10). Furthermore, we observed that the at-risk rs10272859[G] allele was significantly associated with higher mRNA expression levels of CDK14 in liver tissues. Chromosome conformation capture assays in liver cells confirmed that a physical interaction exists between the promoter region of CDK14 and the risk-associated SNPs in strong linkage disequilibrium with the index rs10272859 at 7q21.13. This index rs10272859 also showed significant association with the survival of HCC patients.Conclusions: Our findings highlight a novel locus at 7q21.13 conferring both susceptibility and prognosis to HBV-related HCC, and suggest the CDK14 gene to be the functional target of the 7q21.13 locus. Clin Cancer Res; 24(4); 906-15. ©2017 AACR.

Identification of additional EHMT2 variant associated with the risk of chronic hepatitis B by GWAS follow-up study

Chronic hepatitis B (CHB) is a precursor to liver cirrhosis and hepatocellular carcinoma, caused by a Hepatitis B viral infection. Genome-wide association studies (GWASs) have been conducted to find genes associated with CHB risk. In previous GWAS, EHMT2 was identified as one of the susceptibility genes for CHB. To further characterize this association and discover possible causal variants, we conducted an additional association study. A total of 11 EHMT2 single-nucleotide polymorphisms (SNP) were selected and genotyped in 3902 subjects (1046 CHB patients and 2856 controls). An additional eight imputed SNPs were also included in further analysis. As a result, rs35875104 showed a strong association with the CHB, along with the previously reported genetic marker for CHB risk, rs652888 (odds ratio (OR) = 0.53, P = 2.20 × 10^-8 at rs35875104 and OR = 1.58, P = 9.90 × 10^-12 at rs652888). In addition, linkage disequilibrium and conditional analysis identified one SNP (rs35875104) as a novel genetic marker for CHB susceptibility. The GRSs (genetic risk scores) were calculated to visualize the combined genetic effects of all known CHB-associated loci, including EHMT2 rs35875104, which was additionally identified in this study. The findings from the present study may be useful for further understanding of the genetic etiology of CHB.

Genetic susceptibility to infectious diseases: Current status and future perspectives from genome-wide approaches

Genome-wide association studies (GWASs) have been widely applied to identify genetic factors that affect complex diseases or traits. Presently, the GWAS Catalog includes > 2800 human studies. Of these, only a minority have investigated the susceptibility to infectious diseases or the response to therapies for the treatment or prevention of infections. Despite their limited application in the field, GWASs have provided valuable insights by pinpointing associations to both innate and adaptive immune response loci, as well as novel unexpected risk factors for infection susceptibility. Herein, we discuss some issues and caveats of GWASs for infectious diseases, we review the most recent findings ensuing from these studies, and we provide a brief summary of selected GWASs for infections in non-human mammals. We conclude that, although the general trend in the field of complex traits is to shift from GWAS to next-generation sequencing, important knowledge on infectious disease-related traits can be still gained by GWASs, especially for those conditions that have never been investigated using this approach. We suggest that future studies will benefit from the leveraging of information from the host's and pathogen's genomes, as well as from the exploration of models that incorporate heterogeneity across populations and phenotypes. Interactions within HLA genes or among HLA variants and polymorphisms located outside the major histocompatibility complex may also play an important role in shaping the susceptibility and response to invading pathogens.

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Relatively few GWASs for infectious diseases were performed.

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Phenotype heterogeneity and case/control misclassification can affect GWAS power.

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Adaptive and innate immunity loci were identified in several infectious disease GWASs.

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Unexpected loci (e.g., lncRNAs) were also associated with infection susceptibility.

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GWASs should integrate host and pathogen diversity and use complex association models.

A genome-wide association meta-analysis of diarrhoeal disease in young children identifies FUT2 locus and provides plausible biological pathways

More than a million childhood diarrhoeal episodes occur worldwide each year, and in developed countries a considerable part of them are caused by viral infections. In this study, we aimed to search for genetic variants associated with diarrhoeal disease in young children by meta-analyzing genome-wide association studies, and to elucidate plausible biological mechanisms. The study was conducted in the context of the Early Genetics and Lifecourse Epidemiology (EAGLE) consortium. Data about diarrhoeal disease in two time windows (around 1 year of age and around 2 years of age) was obtained via parental questionnaires, doctor interviews or medical records. Standard quality control and statistical tests were applied to the 1000 Genomes imputed genotypic data. The meta-analysis (N = 5758) followed by replication (N = 3784) identified a genome-wide significant association between rs8111874 and diarrhoea at age 1 year. Conditional analysis suggested that the causal variant could be rs601338 (W154X) in the FUT2 gene. Children with the A allele, which results in a truncated FUT2 protein, had lower risk of diarrhoea. FUT2 participates in the production of histo-blood group antigens and has previously been implicated in the susceptibility to infections, including Rotavirus and Norovirus Gene-set enrichment analysis suggested pathways related to the histo-blood group antigen production, and the regulation of ion transport and blood pressure. Among others, the gastrointestinal tract, and the immune and neuro-secretory systems were detected as relevant organs. In summary, this genome-wide association meta-analysis suggests the implication of the FUT2 gene in diarrhoeal disease in young children from the general population.

Correlations between ASCC3 Gene Polymorphisms and Chronic Hepatitis B in a Chinese Han Population

We have previously identified 8 SNPs in Han Chinese HBV carriers that are associated with disease progression. Although not well studied, genetic factors may also play a significant role in developing chronic HBV disease after exposure. We extend the effect of these eight SNPs on persistent HBV infection in this study. A total of 875 unrelated Han Chinese, 493 chronic hepatitis B subjects (CHB) and 382 HBV clearance individuals (Clear), were recruited from Hubei Province from September 2007 to March 2010. SNPs were verified by using TaqMan 7900HT Sequence Detection System. By using multiple logistic regression analysis, each of the 8 SNP associations was tested using 3 different genetic models (Dominant, Recessive and Additive model), in 4 types of analyses (full sample, men, women, age stratified). A Bonferroni correction was used to account for multiple statistical tests for each SNP association (P<0.05/8 = 0.0063). A significant correlation was observed at SNP rs10485138 located in ASCC3 gene in female patients (OR, 0.445; 95% CI, 0.253–0.784; P = 0.005). Females bearing C allele infected by HBV had an increased susceptibility to CHB compared with those T allele carriers. Our results indicated that SNP rs10485138 located in ASCC3 gene was associated with persistent HBV infection in Han Chinese.

Interleukin-28 gene polymorphisms may contribute to HBsAg persistence and the development of HBeAg-negative chronic hepatitis B

BACKGROUND & AIMS

Aim of this study was to investigate whether a potential association exists between several single nucleotide polymorphisms (SNPs) of the IL-28B gene (rs12979860, rs1188122, rs8099917, rs8105790, rs12980275) and HBsAg persistence. Further, a potential effect on the development of HBeAg-negative CHB vs. inactive HBsAg carrier state was assessed in a genotype D HBV cohort. A cohort of chronic HDV patients was also used to see if they behave differently compared to chronic HBV patients.

METHODS

This study was conducted in three main patient cohorts: Group 1 consisted of 482 patients with HBsAg persistence. Of them 143 were inactive carriers, 94 had HBeAg-positive chronic hepatitis B (CHB) and 245 had anti-HBe-positive CHB. Group 2 represents spontaneously recovered HBV patients; they were anti-HBs and anti-HBc positive. Group 3 consisted of 176 chronic hepatitis delta (CHD) patients with antidelta and HDV-RNA positivity. DNA sequencing was performed for genotyping.

RESULTS

When patients with HBsAg persistence were compared with spontaneously recovered patients, a significant difference was observed for rs8105790 (P < 0.0001), rs12980275 (P < 0.02). Patients who had the CC/TC genotype for rs8105790 (P < 0.0001) and AA genotype for 1188122 (P < 0.02) were more likely to be inactive HBsAg carriers, when inactive HBsAg carriers were compared with HBeAg-negative CHB patients. Comparison of CHD patients vs. recovered HBV patients was parallel to that of HBV persistence vs. recovered HBV with similar significant differences in same SNPs.

CONCLUSION

These results suggest that IL-28B polymorphisms may contribute to HBsAg persistence and the development of the inactive HBsAg carrier state.

Genomics and infectious disease: a call to identify the ethical, legal and social implications for public health and clinical practice

Advances in genomics are contributing to the development of more effective, personalized approaches to the prevention and treatment of infectious diseases. Genetic sequencing technologies are furthering our understanding of how human and pathogen genomic factors - and their interactions - contribute to individual differences in immunologic responses to vaccines, infections and drug therapies. Such understanding will influence future policies and procedures for infectious disease management. With the potential for tailored interventions for particular individuals, populations or subpopulations, ethical, legal and social implications (ELSIs) may arise for public health and clinical practice. Potential considerations include balancing health-related benefits and harms between individuals and the larger community, minimizing threats to individual privacy and autonomy, and ensuring just distribution of scarce resources. In this Opinion, we consider the potential application of pathogen and host genomic information to particular viral infections that have large-scale public health consequences but differ in ELSI-relevant characteristics such as ease of transmission, chronicity, severity, preventability and treatability. We argue for the importance of anticipating these ELSI issues in advance of new scientific discoveries, and call for the development of strategies for identifying and exploring ethical questions that should be considered as clinical, public health and policy decisions are made.

Quantitative genetics in the study of virus-induced disease

While the role of viral variants has long been known to play a key role in causing variation in disease severity, it is also clear that host genetic variation plays a critical role in determining virus-induced disease responses. However, a variety of factors, including confounding environmental variables, rare genetic variants requiring extremely large cohorts, the temporal dynamics of infections, and ethical limitation on human studies, have made the identification and dissection of variant host genes and pathways difficult within human populations. This difficulty has led to the development of a variety of experimental approaches used to identify host genetic contributions to disease responses. In this chapter, we describe the history of genetic associations within the human population, the development of experimentally tractable systems, and the insights these specific approaches provide. We conclude with a discussion of recent advances that allow for the investigation of the role of complex genetic networks that underlie host responses to infection, with the goal of drawing connections to human infections. In particular, we highlight the need for robust animal models with which to directly control and assess the role of host genetics on viral infection outcomes.

Variants identified by hepatocellular carcinoma and chronic hepatitis B virus infection susceptibility GWAS associated with survival in HBV-related hepatocellular carcinoma

Recent genome-wide association studies (GWAS) have identified several common susceptibility loci associated with the risk of hepatocellular carcinoma (HCC) or chronic hepatitis B infection (CHB). However, the relationship between these genetic variants and survival of patients with hepatitis B virus (HBV)-related HCC is still unknown. In this study, 22 single nucleotide polymorphisms (SNPs) were genotyped among 330 HBV-related HCC patients using the MassARRAY system from Sequenom. Cox proportional hazards regression was used to examine the effects of genotype on survival time under an additive model with age, sex, smoking status and clinical stage as covariates. We identified four SNPs on 6p21 (rs1419881 T>C, rs7453920 G>A,rs3997872 G>A and rs7768538 T>C), and two SNPs on 8p12 (rs2275959 C>T and rs7821974 C>T) significantly associated with survival time of HBV-related HCC patients. Our results suggest that HCC or CHB susceptibility loci might also affect the prognosis of patients with HBV-related HCC.

Disentangling pooled triad genotypes for association studies

Association studies that genotype affected offspring and their parents (triads) offer robustness to genetic population structure while enabling assessments of maternal effects, parent-of-origin effects, and gene-by-environment interaction. We propose case-parents designs that use pooled DNA specimens to make economical use of limited available specimens. One can markedly reduce the number of genotyping assays required by randomly partitioning the case-parent triads into pooling sets of h triads each and creating three pools from every pooling set, one pool each for mothers, fathers, and offspring. Maximum-likelihood estimation of relative risk parameters proceeds via log-linear modeling using the expectation-maximization algorithm. The approach can assess offspring and maternal genetic effects and accommodate genotyping errors and missing genotypes. We compare the power of our proposed analysis for testing offspring and maternal genetic effects to that based on a difference approach and that of the gold standard based on individual genotypes, under a range of allele frequencies, missing parent proportions, and genotyping error rates. Power calculations show that the pooling strategies cause only modest reductions in power if genotyping errors are low, while reducing genotyping costs and conserving limited specimens.

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.

Influence of cytotoxic T lymphocyte-associated antigen 4 polymorphisms on the outcomes of hepatitis B virus infection

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) regulates T-cell activation and Th1/Th2 cytokine production and is involved in the immune response against Hepatitis B virus (HBV) infection. To detect the association of the CTLA-4 gene polymorphisms with susceptibility to HBV infection a hospital-based case-control study was conducted. A total of 1,119 unrelated individuals were recruited. The CTLA-4 variants rs5742909, rs231775 and rs3087243 were genotyped via the TaqMan method in this cohort. A comparison with a chronic active hepatitis B group revealed that the SNP rs231775 exhibited significant susceptibility to HBV progression, with the highest odds ratio (OR) reaching 1.659 and P=0.009-0.049. Although an HBV clearance group was used as a control, results of the present study demonstrated an association of rs5742909 with viral persistence [OR=1.694, 95% confidence intervals (CI)=1.124-2.553 and P=0.012]. Subsequent analyses revealed risk haplotypes (C-A-A and T-A-G, for which the highest OR reached 1.865) compared with the protective haplotype C-G-G. Therefore, SNPs in the CTLA-4 gene may be associated with HBV progression and viral persistence which is consistent with its emerging role in the T regulatory cells in the pathogenesis of disease.

DNA pooling base genome-wide association study identifies variants at NRXN3 associated with delayed encephalopathy after acute carbon monoxide poisoning

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is more characteristic of anoxic encephalopathy than of other types of anoxia. Those who have the same poisoning degree and are of similar age and gender have a greater risk of getting DEACMP. This has made it clear that there are obvious personal differences. Genetic factors may play a very important role. The authors performed a genome-wide association study involving pooling of DNA obtained from 175 patients and 244 matched acute carbon monoxide poisoning without delayed encephalopathy controls. The Illumina HumanHap 660 Chip array was used for DNA pools. Allele frequencies of all SNPs were compared between delayed encephalopathy after acute carbon monoxide poisoning and control groups and ranked. A total of 123 SNPs gave an OR >1.4. Of these, 46 mapped in or close to known genes. Forty-eight SNPs located in 19 genes were associated with DEACMP after correction for 5% FDR in the genome-wide association of pooled DNA. Two SNPs (rs11845632 and rs2196447) locate in the Neurexin 3 gene were selected for individual genotyping in all samples and another cohort consisted of 234 and 271 controls. There were significant differences in the genotype and allele frequencies of rs11845632 and rs2196447 between the DEACMP group and controls group (all P-values <0.05). This study describes a positive association between Neurexin 3 and controls in the Han Chinese population, and provides genetic evidence to support the susceptibility of DEACMP, which may be the resulting interaction of environmental and genetic factors.

Systems immunogenetics of vaccines

Vaccines are the most cost effective public health measure for preventing viral infection and limiting epidemic spread within susceptible populations. However, the efficacy of current protective vaccines is highly variable, particularly in aging populations. In addition, there have been a number of challenges in the development of new vaccines due to a lack of detailed understanding of the immune correlates of protection. To identify the mechanisms underlying the variability of the immune response to vaccines, system-level tools need to be developed that will further our understanding of virus-host interactions and correlates of vaccine efficacy. This will provide critical information for rational vaccine design and allow the development of an analog to the "precision medicine" framework (already acknowledged as a powerful approach in medicine and therapeutics) to be applied to vaccinology.

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.