Evaluation of genetic susceptibility loci for chronic hepatitis B in Chinese: two independent case-control studies

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.

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.

Assessment of HLADP gene rs3128917 and rs9380343 polymorphisms in chronic HBV infection

BACKGROUND/AIMS

About 400 million people worldwide have been exposed to Hepatitis B (HBV) infection. A range of 10%-15% of chronic HBV carriers may present with various liver diseases including cirrhosis and hepatic cancer. The chronicity or clearance of HBV infection is dependent on viral and genetic variables. Genome-wide association studies (GWAS) have reported that the variants of human leukocyte antigen (HLA), rs3128917 and rs9380343, are significantly related to persistent HBV infection. HLA molecules are responsible for introducing various antigens into the immune system. These variants might affect antigen presentation by influencing HLA mRNA expression, therefore, antigen presentation may not be performed properly. This study aims to assess the relationship of HLA gene variants to chronic HBV infection.

MATERIALS AND METHODS

HLA variants were explored in 238 chronic HBV patients and in 238 individuals with spontaneous clearance of HBV using PCR-RFLP assay.

RESULTS

The allele and genotype of rs9380343 polymorphism were associated with persistent HBV infection risk (allele: p=0.038, genotype: p=0.029), but rs3128917 polymorphism was not significant. Additionally, rs9380343 polymorphism was also related to increased risk of HBV infection in males (p<0.05).

CONCLUSION

The current study is the first report demonstrating the HLA rs9380343 polymorphism as a genetic risk factor for chronicity of HBV infection. Further independent studies are required to confirm the current findings using a larger sample size in different populations.

GWAS identifying HLA-DPB1 gene variants associated with responsiveness to hepatitis B virus vaccination in Koreans: Independent association of HLA-DPB1*04:02 possessing rs1042169 G - rs9277355 C - rs9277356 A

Recently, HLA class II loci, including HLA-DPB1, have been reported to be associated with interindividual variance in the hepatitis B (HB) vaccine response. In this study, we investigated significant single nucleotide polymorphisms (SNPs) for anti-HBs antibody levels in 6867 healthy Koreans using a genome-wide association study (GWAS). In GWAS, the top 20 SNPs that showed significant association with anti-HBs levels (P < 1.0 × 10^-29 ) all resided in HLA-DPB1. Utilizing PCR sequencing, we verified the relationship of the top 3 most significant SNPs (rs1042169, rs9277355 and rs9277356) from the GWAS and genotypes of HLA-DPB1 with the HB vaccine response in Korean infants who received a scheduled vaccination. The DPB1*04:02 allele has G, C and A nucleotides for the 3SNP sites, and was significantly more frequent in responders than in nonresponders (10.9% vs 1.0%, P_c  = 0.018). DPB1*05:01 was significantly more frequent in nonresponders than in responders (49.0% vs 31.1%, P_c  = 0.018). In multivariate logistic regression, DPB1*04:02 showed a significant association with both vaccine response (P = 0.037, OR = 8.465) and high-titre response (P = 0.027, OR = 9.860). The haplotypes rs1042169 G - rs9277355 C - rs9277356 A showed a significant association with a high-titre response only (P = 0.002, OR = 2.941). In conclusion, DPB1*04:02 possessing rs1042169 G - rs9277355 C - rs9277356 A is an independent predictor of the HB vaccine response in Koreans.

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.

Association of HLA-DPA1 and HLA-DPB1 polymorphisms with spontaneous HBsAg seroclearance in Caucasians

BACKGROUND & AIMS

Acute hepatitis B virus (HBV) infections may clear spontaneously or become chronic and run through different phases. The single nucleotide polymorphisms (SNPs) rs3077, rs9277535 and rs9277534 within the human leucocyte antigen (HLA)-DP gene have been found to be associated with HBV susceptibility and persistence in Asians. However, evidence for the influence of these variants in Caucasians has been limited so far. The aim of our study was to investigate the impact of these polymorphisms on the outcome of HBV infections in a large Caucasian population.

METHODS

In this case-control study, we retrospectively analysed 1111 Caucasian individuals, including 618 with chronic HBV infections (CHB), 239 with spontaneous HBsAg seroclearance (SC) and 254 healthy controls (HC). The rs3077, rs9277535 and rs9277534 SNPs were genotyped by a polymerase chain reaction from blood samples and melting curve analysis.

RESULTS

A significant difference in the allele distributions was observed only for the rs3077 SNP between the HC and the CHB group as well as between the SC and CHB groups. The rs3077-C allele was associated with a lower probability for spontaneous HBsAg seroclearance in comparison with the rs3077-T allele (OR 0.704, 95% CI 0.509-0.974; P = 0.033). No association of the three SNPs with the stages of chronic HBV infection was found.

CONCLUSION

This is the first study demonstrating an association of the rs3077-T allele with spontaneous HBsAg seroclearance in Caucasians. Further studies are needed to elucidate the role of HLA-DP variants in disease pathogenesis and their potential role for individualized disease management.

Progress of research on the immune tolerance of chronic HBV infection

Immune tolerance is a specific lack or negative response of T and B lymphocytes to antigen. According to different formation periods, immune tolerance can be divided into central and peripheral tolerances. The immune tolerance of the body to hepatitis B virus (HBV) after infection is the main cause of chronic HBV infection. In this paper, the functional defects of hepatitis B virus e antigen and dendritic cells, hyporesponsiveness of cytotoxic T lymphocyte, variation of helper T lymphocytes and cytokines, HBV genotype and genome, and the role of host gene polymorphism in the formation of immune tolerance in chronic HBV infection and its related research progress are introduced briefly.

Host genetic factors affecting hepatitis B infection outcomes: Insights from genome-wide association studies

The clinical outcome of Hepatitis B Virus (HBV) infection depends on the success or failure of the immune responses to HBV, and varies widely among individuals, ranging from asymptomatic self-limited infection, inactive carrier state, chronic hepatitis, cirrhosis, hepatocellular carcinoma, to liver failure. Genome-wide association studies (GWAS) identified key genetic factors influencing the pathogenesis of HBV-related traits. In this review, we discuss GWAS for persistence of HBV infection, antibody response to hepatitis B vaccine, and HBV-related advanced liver diseases. HBV persistence is associated with multiple genes with diverse roles in immune mechanisms. The strongest associations are found within the classical human leukocyte antigen (HLA) genes, highlighting the central role of antigen presentation in the immune response to HBV. Associated variants affect both epitope binding specificities and expression levels of HLA molecules. Several other susceptibility genes regulate the magnitude of adaptive immune responses, determining immunity vs tolerance. HBV persistence and nonresponse to vaccine share the same risk variants, implying overlapping genetic bases. On the other hand, the risk variants for HBV-related advanced liver diseases are largely different, suggesting different host-virus dynamics in acute vs chronic HBV infections. The findings of these GWAS are likely to pave the way for developing more effective preventive and therapeutic interventions by personalizing the management of HBV infection.

Role of HLA-DP and HLA-DQ on the clearance of hepatitis B virus and the risk of chronic infection in a multiethnic population

BACKGROUND & AIMS

HBV infection exhibits geographical variation in its distribution in South America. While HBV rates are low in central Argentina, the north-western region exhibits intermediate HBV rates. Unfortunately, the reasons that could explain this difference are still unknown.

METHODS

A total of 1440 Argentines were recruited and grouped into HBV patients, HBV-resolved individuals and healthy controls. Genetic ancestry was assessed by analysis of biparental lineages and ancestry autosomal typing. SNPs of HLA-DPA1 (rs3077), HLA-DPB1 (rs9277542), HLA-DQB1 (rs2856718) and HLA-DQB2 (rs7453920) were determined, and HBV genotyping was performed by phylogenetic analysis in HBV patients.

RESULTS

Native American ancestry prevailed in the north-western region when compared with central Argentina (P<.0001). However, no differences were observed among the three groups of each region. The distribution of HBV genotypes revealed significant differences (P<.0001). Three SNPs (rs3077, rs9277542 and rs7453920) showed a significant association with protection against chronic HBV and viral clearance in both regions. The remaining SNP showed a significant association with susceptibility to chronic HBV. The frequency rates of rs3077-T, related to protection against chronic HBV and viral clearance, were lower in north-western Argentina when compared with central Argentina. The same uneven frequency rates were observed for SNP rs9277542.

CONCLUSIONS

This is the first study addressing the associations between the HLA-DP and HLA-DQ loci and the protection against chronic HBV and viral clearance in a multiethnic South American population. The uneven distribution of HLA-DP and HLA-DQ supports the HBV epidemiological differences observed in these two regions of Argentina with dissimilar ancestry genetic background.

Cytochrome P450 Genes (CYP2E1 and CYP1A1) Variants and Susceptibility to Chronic Hepatitis B Virus Infection

Hepatitis B virus (HBV) infection is a worldwide health concern which is associated with significant morbidity and mortality. Both viral and host factors have a significant effect on infection, replication and pathogenesis of HBV. The aim of this study was to investigate the effect of CYP2E1 and CYP1A1 genetic variants on susceptibility to HBV. 143 individuals including 54 chronic HBV patients and 89 healthy controls were enrolled in the genotyping procedure. rs2031920 and rs3813867 at CYP2E1 as well as rs4646421 and rs2198843 at CYP1A1 loci were studied in all subjects using PCR-RFLP (restriction fragment length polymorphism) analysis. Both variants at CYP2E1 locus were monomorphic in all studied subjects. Genotype frequency of rs4646421 was significantly different between chronic HBV patients and healthy blood donors (P = 0.04, OR 4.31; 95% CI 1.04-17.7). Furthermore, individuals carrying at least one C allele (CC or CT genotypes) for rs4646421 seemed to have a decrease risk of hepatitis in comparison with TT genotype (P = 0.039). Our results showed a relationship between rs4646421 TT genotype (rare genotype) and the risk for developing chronic HBV infection (four times higher). Further studies are needed to examine the role of CYP1A1 polymorphism in susceptibility to chronic HBV infection.

Correlation of HLA-DP/DQ polymorphisms with transplant etiologies and prognosis in liver transplant recipients

Previous study has identified that the genetic variants in the human leukocyte antigen (HLA)-DP/DQ region were strongly associated with hepatitis B virus (HBV) infection. But their roles in liver function recovery after hepatic transplantation were still obscure. This study aimed to investigate whether HLA-DP/DQ polymorphisms were associated with post-transplant etiologies and prognosis in Chinese liver transplant recipients.A total of 144 liver transplant recipients were enrolled, which were divided into 2 groups according to the transplant etiology: HBV-related disease and non-HBV-related disease. HBV-related disease includes 3 subgroups: liver cirrhosis, hepatocellular carcinoma, and progressive HBV hepatitis. Three single-nucleotide polymorphisms HLA-DP (rs3077 and rs9277535) and HLA-DQ (rs7453920) were studied in all recipients by high-resolution melting curve analysis. Liver function indices (albumin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltranspeptidase, direct bilirubin, total bilirubin) and coagulation indices (prothrombin time, platelet, international normalized ratio, fibrinogen) were routinely tested. After transplant, 10 recipients who were positive for HBsAg or with elevation in HBV virus load were regarded as HBV recurrence.No significant association of HLA-DP/DQ polymorphisms with HBV recurrence or transplant etiology was observed (P < .05). Recipients with HLA-DQ (rs7453920) AG and AA genotype had lower direct bilirubin levels than GG genotype individuals, especially on the 14th day after surgery (17.80 vs. 5.35, P  =  .038). Patients with A alleles displayed earlier liver function recovery than patients with G alleles (7 vs. 6 months). No significant correlation was shown in HLA-DP rs3077 and rs9277535 with HBV infection or liver function recovery (P < .05).Our study concluded that HLA-DP (rs3077 and rs9277535) and HLA-DQ (rs7453920) were not significantly associated with HBV recurrence or HBV susceptibility, but HLA-DQ rs7453920 was related to prognosis of liver transplant recipients. HLA-DQ rs7453920 A might be used as an indicator of earlier recovery and better prognosis after transplantation.

Association between chronic hepatitis B virus infection and HLA-DP gene polymorphisms in the Turkish population

AIM

Hepatitis B virus (HBV) affects approximately 360 million people worldwide. 10-15% of patients with chronic HBV develop liver cirrhosis (LC), liver failure and hepatocellular carcinoma (HCC). Chronic HBV infection or HBV clearance is influenced by both viral and host factors. In genome-wide association studies (GWAS), the human leukocyte antigen (HLA) gene polymorphisms rs3077 and rs9277535 were identified to be associated with chronic hepatitis B. HLA genes have been linked to immune response to infectious agents. Genetic variants in HLA genes influence HLA mRNA expression which might also affect antigen presentation. We evaluated the association between HLA gene polymorphisms and the risk for persistent HBV infection.

METHODS

In the current study, HLA gene polymorphisms were investigated in a case-control study of 294 chronic HBV patients and 234 persons with HBV natural clearance by using a real-time polymerase chain reaction (RT-PCR).

RESULTS

The results showed that rs9277535 allele frequency is associated with HBV infection in the Turkish subjects examined (P=0.048). However, no association was found for rs3077. Additionally, the AG haplotype block showed a protective effect against the risk of persistent HBV infection (for the rs3077A/rs9277535G, OR=0.52; 95% 0.34-0.80, P=0.003).

CONCLUSIONS

Our results, for the first time, demonstrate that HLA-DPB1 gene rs9277535A allele has a major effect on the risk of persistent HBV infection. We suggest that further independent studies are necessary to clarify the association of these polymorphisms with persistence or natural clearance of HBV infection in Caucasian populations.

Treatment of hepatitis B virus: an update

Chronic hepatitis B virus infection is a global health concern as it affects over 240 million people worldwide and an estimated 686,000 people die annually as a result of complications of the disease. With the development of newer antiviral drugs, viral suppression of HBV is achievable, however elimination of HBV from infected individuals (functional cure) remains an issue. Due to persistence of HBV DNA (cccDNA) in infected cells, chronically infected patients who discontinue therapy prior to HBsAg loss or seroconversion are likely to relapse. Several novel therapeutic strategies are being researched and studied in clinical trials. Here we review these novel strategies to achieve sustained cure or elimination of HBV. These strategies include the targeting of the host or viral factors required for viral persistence as well as therapeutic vaccines.

Clinical Relevance of HLA Gene Variants in HBV Infection

Host gene variants may influence the natural history of hepatitis B virus (HBV) infection. The human leukocyte antigen (HLA) system, the major histocompatibility complex (MHC) in humans, is one of the most important host factors that are correlated with the clinical course of HBV infection. Genome-wide association studies (GWASs) have shown that single nucleotide polymorphisms (SNPs) near certain HLA gene loci are strongly associated with not only persistent HBV infection but also spontaneous HBV clearance and seroconversion, disease progression, and the development of liver cirrhosis and HBV-related hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB). These variations also influence the efficacy of interferon (IFN) and nucleot(s)ide analogue (NA) treatment and response to HBV vaccines. Meanwhile, discrepant conclusions were reached with different patient cohorts. It is therefore essential to identify the associations of specific HLA allele variants with disease progression and viral clearance in chronic HBV infection among different ethnic populations. A better understanding of HLA polymorphism relevance in HBV infection outcome would enable us to elucidate the roles of HLA SNPs in the pathogenesis and clearance of HBV in different areas and ethnic groups, to improve strategies for the prevention and treatment of chronic HBV infection.

Association of HLA-DP variants with the responsiveness to Hepatitis B virus vaccination in Korean Infants

Recently, HLA-DP single nucleotide polymorphisms (SNPs) have been reported to be related to responsiveness to hepatitis B virus (HBV) vaccination. The aim of this study was to investigate associations between HLA-DP SNPs and responsiveness to HBV vaccine in Korean infants. A total of 290 healthy Korean infants who were registered to Seoul Metropolitan Public Cord Blood Bank during the period of February 2007 to December 2011 were enrolled. Anti-HBs antibody level was analyzed after three doses of HBV vaccination. Genotyping of HLA-DPA1 SNPs (rs3077 and rs3830066) and HLA-DPB1 SNPs (rs7770370, rs7770501, rs3128961, and rs9277535) were performed by PCR-sequencing. HLA-A, -B, and -DRB1 genotyping was also performed by PCR-sequence-specific oligonucleotide probe kits. HLA-DPB1 SNPs (rs7770370, rs7770501, rs3128961, and rs9277535) were associated with HBV vaccine response. Allele frequencies of rs7770370 A, rs7770501 C, rs3128961 G, and rs9277535 A were significantly higher in responders than in non-responders (all p<0.01). Anti-HBs antibody levels were different according to genotypes of DPB1 rs7770370, rs7770501, rs3128961, and rs9277535 (all p<0.01). In multivariate analysis, HLA-DPB1 rs7770370 AA genotype was significantly associated with HBV vaccine response (relative risk, RR=2.5, p=0.033) and high-titer vaccine response (RR=2.7, p<0.001). In conclusion, HLA-DPB1 SNPs were significantly associated with responses to HBV vaccination in Korean infants.

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.

Influence of multiple factors on the incidence of occupational blood and body fluid exposures in health care workers in Guizhou, China: A structural equation modeling approach

BACKGROUND

We investigated the influence of multiple factors on the incidence of occupational blood and body fluid exposures (BBFEs) in health care workers (HCWs) in Guizhou, China, using structural equation modeling (SEM).

METHODS

SEM tested in general hospitals was evaluated using survey data from a sample of 1,774 HCWs from 25 hospitals in Guizhou, China, between January and April 2014.

RESULTS

The incidence of occupational BBFEs in HCWs was affected by HCWs' knowledge of safe work practices, HCWs' belief in their ability to use safe work practices, HCWs' use of safe work practices, the workplace safety environment, sufficiency of the controls implemented at health care facilities, and workloads. Knowledge of safe work practices had the most influence on the incidence of occupational BBFE in doctors and laboratory technicians. Ability to use safe work practices had the most influence on the incidence of occupational BBFEs in nurses.

CONCLUSION

The workplace safety environment, sufficiency of controls implemented at health care facilities, HCWs' knowledge of safe work practices, HCWs' belief in their ability to use safe work practices, HCWs' use of safe work practices, and workload influence the incidence of occupational BBFEs in HCWs.

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

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

Genetic susceptibility to cervical squamous cell carcinoma is associated with HLA-DPB1 polymorphisms in Taiwanese women

Cervical cancer is a multifactorial disease, and increasing evidence suggests that host immunogenetic background may contribute to its pathogenesis. Genetic variations in human leukocyte antigen (HLA) genes may alter the efficiency of immune response to human papillomavirus (HPV) antigens and have been implicated in the risk of cervical cancer. We investigated whether polymorphisms in the HLA-DPB1 gene were associated with cervical cancer risk in a Taiwanese population. HLA-DPB1 alleles and +550 G/A polymorphism were genotyped in a case-control study of 473 women with cervical squamous cell carcinoma (CSCC) and 676 healthy controls. The presence and genotypes of HPV in CSCC were determined. We found that the DPB1*05:01 and +550 A alleles were associated with decreased and increased risk of CSCC, respectively [odds ratio (OR) = 0.72, Pc = 0.001; OR = 1.25, Pc = 0.03]. In subgroup analysis based on HPV type 16 positivity, significant associations were shown in the DPB1*05:01 and *13:01 alleles (OR = 0.65, Pc = 0.0007; OR = 1.83, Pc = 0.004). Furthermore, the DPB1*05:01-G and *13:01-G haplotypes conferred decreased and increased risk of both CSCC and HPV-16 positive CSCC women, respectively (OR = 0.72, Pc = 0.0009; OR = 0.63, Pc = 0.0004 for DPB1*05:01-G; OR = 1.55, Pc = 0.03; OR = 1.84, Pc = 0.004 for DPB1*13:01-G). A risk haplotype DPB1*02:01-A was also observed in the HPV-16 positive CSCC women (OR = 1.51, Pc = 0.05). These findings suggest that HLA-DPB1 gene is involved in the CSCC development.

Host genetic variants influencing the clinical course of hepatitis B virus infection

The clinical course of hepatitis B virus (HBV) infection greatly differs in individuals. Various viral, host, and environmental factors influence the natural history of HBV infection. Recent genome-wide association studies identified several host genetic factors influencing the clinical course of HBV infection. Genetic variations in HLA class II loci were significantly associated with susceptibility to persistent HBV infection. Other polymorphisms in or near the genes EHMT2, TCF19, and HLA-C, located near HLA class II loci, and UBE2L3 were also associated with persistent HBV infection. Meanwhile, polymorphisms in KIF1B, GRIK1, and STAT4 were associated with HBV-related hepatocellular carcinoma (HCC). Interestingly, HLA class II genetic variations were strongly associated with not only persistent HBV infection, but also disease progression and HBV-related HCC in chronic hepatitis B. Understanding the various genetic factors associated with the clinical course of HBV infection is essential for personalized treatment and surveillance of disease progression and HCC.

Genetic variants in five novel loci including CFB and CD40 predispose to chronic hepatitis B

Hepatitis B virus affects more than 2 billion people worldwide, 350 million of which have developed chronic hepatitis B (CHB). The genetic factors that confer CHB risk are still largely unknown. We sought to identify genetic variants for CHB susceptibility in the Chinese population. We undertook a genome-wide association study (GWAS) in 2,514 CHB cases and 1,130 normal controls from eastern China. We replicated 33 of the most promising signals and eight previously reported CHB risk loci through a two-stage validation totaling 6,600 CHB cases and 8,127 controls in four independent populations, of which two populations were recruited from eastern China, one from northern China and one from southern China. The joint analyses of 9,114 CHB cases and 9,257 controls revealed significant association of CHB risk with five novel loci. Four loci are located in the human leukocyte antigen (HLA) region at 6p21.3, including two nonsynonymous variants (rs12614 [R32W] in complement factor B [CFB], Pmeta =1.28 × 10(-34) ; and rs422951 [T320A] in NOTCH4, Pmeta  = 5.33 × 10(-16) ); one synonymous variant (rs378352 in HLA-DOA corresponding to HLA-DOA*010101, Pmeta  = 1.04 × 10(-23) ); and one noncoding variant (rs2853953 near HLA-C, Pmeta  = 5.06 × 10(-20) ). Another locus is located at 20q13.1 (rs1883832 in the Kozak sequence of CD40, Pmeta  = 2.95 × 10(-15) ). Additionally, we validated seven of eight previously reported CHB susceptibility loci (rs3130542 at HLA-C, rs1419881 at TCF19, rs652888 at EHMT2, rs2856718 at HLA-DQB1, rs7453920 at HLA-DQB2, rs3077 at HLA-DPA1, and rs9277535 at HLA-DPA2, which are all located in the HLA region, 9.84 × 10(-71)  ≤ Pmeta  ≤ 9.92 × 10(-7) ).

CONCLUSION

Our GWAS identified five novel susceptibility loci for CHB. These findings improve the understanding of CHB etiology and may provide new targets for prevention and treatment of this disease.

Association between single-nucleotide polymorphisms and early spontaneous hepatitis B virus e antigen seroconversion in children

Background

The disease progression following hepatitis B virus (HBV) infection is associated with single-nucleotide polymorphisms (SNPs). However, the role of SNPs in chronic HBV infection in children remains unclear. Here, we investigate the association between SNPs and early spontaneous hepatitis B e antigen (HBeAg) seroconversion in children with chronic hepatitis B infection.

Methods

This was a retrospective cohort study. We genotyped seven SNPs in the following genes, interleukin (IL)-10 (rs1800871 and rs1800872), human leukocyte antigen (HLA)-DPA1 (rs3077), HLA-DPB1 (rs9277535), HLA-DQB2 (rs7453920), HLA-DQB1 (rs2856718), and IL28B (rs8099917), in patients with chronic HBV infection using PCR and sequencing. These variants were analyzed for an association with early HBeAg seroconversion in children.

Results

Of 225 Japanese patients with chronic hepatitis B virus infection (male/female: 105/120, median age at initial visit: 6 years; range 0–44 years), 52 achieved spontaneous HBeAg seroconversion at the age of 10 years or younger (G1: early seroconversion group), and 57 did not achieve spontaneous HBeAg seroconversion under the age of 20 years (G2: late or no seroconversion group). Of the seven SNPs, only the HLA-DPA1 SNP displayed a low p-value (P = 0.070), but not significant, to have early HBeAg seroconversion in the dominant model and in the allele model (P =  0.073) using the chi-square test. The association study found a low p-value, but not significant, to have early HBeAg seroconversion in the dominant model for HLA-DPA1 (genotype TC + TT vs. CC, P = 0.070, odds ratio: 2.016, 95% confidence interval: 0.940-4.323) using a logistic regression model.

Conclusion

Although the HLA-DPA1 SNP did not show a statistically significant association with early HBeAg seroconversion in this study, the HLA-DPA1 SNP might increase the likelihood of achieving early spontaneous HBeAg seroconversion in children.

HLA-DPB1 Variant Effect on Hepatitis B Virus Clearance and Liver Cirrhosis Development Among Southwest Chinese Population

BACKGROUND

Previous studies have shown that genetic variants in HLA-DP genes affect disease progression in hepatitis B virus (HBV) infection.

OBJECTIVES

We aimed to evaluate possible association between HLA-DPB1 rs9277534 polymorphism and different clinical complications of hepatitis B virus (HBV) infection.

MATERIALS AND METHODS

Snapshot assay was used to investigate the association of rs9277534 polymorphism in 342 patients with persistent HBV infection and 342 age and gender-matched HBV spontaneous clearance controls. Patients were categorized into asymptomatic HBV carriers (AsC, n = 104), chronic hepatitis B (CHB, n = 116), and liver cirrhosis (LC, n = 122) subgroups.

RESULTS

There was a significantly higher proportion of the rs9277534 minor allele A in HBV spontaneous clearance control than that in HBV persistent infection group (OR = 0.58, 95%CI = 0.46-0.73, P < 0.0001). Genotypic analysis showed that GA and AA genotypes were associated with HBV spontaneous clearance (GA: OR = 0.56, 95%CI = 0.40-0.79, P = 0.019; AA: OR = 0.24, 95%CI = 0.14-0.44, P < 0.0001). A significant difference was found between AsC and LC groups in the distribution of AA genotype (OR = 9.32, 95%CI = 1.293-67.14, P = 0.027).

CONCLUSIONS

Variant at rs9277534 could affect both the spontaneous clearance of HBV infection and progression from asymptomatic HBV carriers to HBV-related liver cirrhosis in Southwest Han Chinese population.

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.

Genetic association of human leukocyte antigens with chronicity or resolution of hepatitis B infection in thai population

BACKGROUND

Previous studies showed that single nucleotide polymorphisms (SNPs) in the HLA-DP, TCF19 and EHMT2 genes may affect the chronic hepatitis B (CHB). To predict the degree of risk for chronicity of HBV, this study determined associations with these SNPs.

METHODS

The participants for this study were defined into 4 groups; HCC (n = 230), CHB (n = 219), resolved HBV infection (n = 113) and HBV uninfected subjects (n = 123). The HLA-DP SNPs (rs3077, rs9277378 and rs3128917), TCF19 SNP (rs1419881) and EHMT2 SNP (rs652888) were genotyped.

RESULTS

Due to similar distribution of genotype frequencies in HCC and CHB, we combined these two groups (HBV carriers). The genotype distribution in HBV carriers relative to those who resolved HBV showed that rs3077 and rs9277378 were significantly associated with protective effects against CHB in minor dominant model (OR = 0.45, p<0.001 and OR = 0.47, p<0.001). The other SNPs rs3128917, rs1419881 and rs652888 were not associated with HBV carriers.

CONCLUSIONS

Genetic variations of rs3077 and rs9277378, but not rs3128917, rs1419881 and rs652888, were significantly associated with HBV carriers relative to resolved HBV in Thai population.

Association between HLA variations and chronic hepatitis B virus infection in Saudi Arabian patients

Hepatitis B virus (HBV) infection is a leading cause of liver diseases including cirrhosis and hepatocellular carcinoma. Human leukocyte antigens (HLAs) play an important role in the regulation of immune response against infectious organisms, including HBV. Recently, several genome-wide association (GWAS) studies have shown that genetic variations in HLA genes influence disease progression in HBV infection. The aim of this study was to investigate the role of HLA genetic polymorphisms and their possible role in HBV infection in Saudi Arabian patients. Variations in HLA genes were screened in 1672 subjects who were divided according to their clinical status into six categories as follows; clearance group, inactive carriers, active carriers, cirrhosis, hepatocellular carcinoma (HCC) patients and uninfected healthy controls. Three single nucleotide polymorphisms (SNPs) belonged to HLA-DQ region (rs2856718, rs7453920 and rs9275572) and two SNPs belonged to HLA-DP (rs3077 and rs9277535) were studied. The SNPs were genotyped by PCR-based DNA sequencing (rs2856718) and allele specific TaqMan genotyping assays (rs3077, rs7453920, rs9277535 and rs9275572). The results showed that rs2856718, rs3077, rs9277535 and rs9275572 were associated with HBV infection (p = 0.0003, OR = 1.351, CI = 1.147–1.591; p = 0.041, OR = 1.20, CI = 1.007–1.43; p = 0.045, OR = 1.198, CI = 1.004–1.43 and p = 0.0018, OR = 0.776, CI = 0.662–0.910, respectively). However, allele frequency of rs2856718, rs7453920 and rs9275572 were found more in chronically infected patients when compared to clearance group infection (p = 0.0001, OR = 1.462, CI = 1.204–1.776; p = 0.0178, OR = 1.267, CI = 1.042–1.540 and p = 0.010, OR = 0.776, CI = 0.639–0.942, respectively). No association was found when polymorphisms in HLA genes were compared in active carriers versus cirrhosis/HCC patients. In conclusion, these results suggest that variations in HLA genes could affect susceptibility to and clearance of HBV infection in Saudi Arabian patients.

A genetic variant in the promoter region of miR-106b-25 cluster predict clinical outcome of HBV-related hepatocellular carcinoma in Chinese

Background

MiR-106b-25 cluster, hosted in intron 13 of MCM7, may play integral roles in diverse processes including immune response, tumorigenesis and progression. A single nucleotide polymorphism (SNP), rs999885, is located in the promoter region of MCM7. Our previous study showed that the A to G base change of rs999885 may provide an increased risk for HCC in HBV persistent carriers by altering the expression of the miR-106b-25 cluster. However, it is unknown whether rs999885 is associated with prognosis of intermediate or advanced HBV-related hepatocellular carcinoma (HCC) patients.

Methods

The SNP, rs999885, was genotyped by using the TaqMan allelic discrimination Assay in 414 intermediate or advanced HCC patients. Log-rank test and Cox proportional hazard models were used for survival analysis.

Results

The variant genotypes of rs999885 were associated with a significantly decreased risk of death for intermediate or advanced HCC [additive model: adjusted hazard ratio (HR)  = 0.76,95% confidence intervals (CI)  = 0.59–0.97]. Further stepwise regression analysis suggested that rs999885 was an independently protective factor for the prognosis of HCC in the final model (additive model: adjusted HR  = 0.72, 95% CI  = 0.56–0.91, P = 0.007).

Conclusions

These findings indicate that the A to G base change of rs999885 may provide a protective effect on the prognosis of intermediate or advanced HCC in Chinese.

A genome-wide association study on chronic HBV infection and its clinical progression in male Han-Taiwanese

It is common to observe the clustering of chronic hepatitis B surface antigen (HBsAg) carriers in families. Intra-familial transmission of hepatitis B virus (HBV) could be the reason for the familial clustering of HBsAg carriers. Additionally, genetic and gender factors have been reported to be involved. We conducted a three-stage genome-wide association study to identify genetic factors associated with chronic HBV susceptibility. A total of 1,065 male controls and 1,623 male HBsAg carriers were included. The whole-genome genotyping was done on Illumina HumanHap550 beadchips in 304 healthy controls and HumanHap610 beadchips in 321 cases. We found that rs9277535 (HLA-DPB1, P = 4.87×10(-14)), rs9276370 (HLA-DQA2, P = 1.9×10(-12)), rs7756516 and rs7453920 (HLA-DQB2, P = 1.48×10(-11) and P = 6.66×10(-15) respectively) were significantly associated with persistent HBV infection. A novel SNP rs9366816 near HLA-DPA3 also showed significant association (P = 2.58×10(-10)). The "T-T-G-G-T" haplotype of the five SNPs further signified their association with the disease (P = 1.48×10(-12); OR = 1.49). The "T-T" haplotype composed of rs7756516 and rs9276370 was more prevalent in severe disease subgroups and associated with non-sustained therapeutic response (P = 0.0262). The "G-C" haplotype was associated with sustained therapeutic response (P = 0.0132; OR = 2.49). We confirmed that HLA-DPB1, HLA-DQA2 and HLA-DQB2 loci were associated with persistent HBV infection in male Taiwan Han-Chinese. In addition, the HLA-DQA2 and -DQB2 complex was associated with clinical progression and therapeutic response.

Strategies to eliminate HBV infection

Chronic HBV infection is a major public health concern affecting over 240 million people worldwide. Although suppression of HBV replication is achieved in the majority of patients with currently available newer antivirals, discontinuation of therapy prior to hepatitis B surface antigen loss or seroconversion is associated with relapse of HBV in the majority of cases. Thus, new therapeutic modalities are needed to achieve eradication of the virus from chronically infected patients in the absence of therapy. The basis of HBV persistence includes viral and host factors. Here, we review novel strategies to achieve sustained cure or elimination of HBV. The novel approaches include targeting the viral and or host factors required for viral persistence, and novel immune-based therapies, including therapeutic vaccines.

New loci associated with chronic hepatitis B virus infection in Han Chinese

Chronic hepatitis B virus (HBV) infection is a challenging global health problem. To identify genetic loci involved in chronic HBV infection, we designed a three-phase genome-wide association study in Han Chinese populations. The discovery phase included 951 HBV carriers (cases) and 937 individuals who had naturally cleared HBV infection (controls) and was followed by independent replications with a total of 2,248 cases and 3,051 controls and additional replications with 1,982 HBV carriers and 2,622 controls from the general population. We identified two new loci associated with chronic HBV infection: rs3130542 at 6p21.33 (near HLA-C, odds ratio (OR) = 1.33, P = 9.49 × 10(-14)) and rs4821116 at 22q11.21 (in UBE2L3, OR = 0.82, P = 1.71 × 10(-12)). Additionally, we replicated the previously identified associations of HLA-DP and HLA-DQ variants at 6p21.32 with chronic HBV infection. These findings highlight the importance of HLA-C and UBE2L3 in the clearance of HBV infection in addition to HLA-DP and HLA-DQ.

The SNP rs402710 in 5p15.33 is associated with lung cancer risk: a replication study in Chinese population and a meta-analysis

Background

Lung cancer is the most commonly diagnosed cancer and leading cause of cancer mortality in the world. A single nucleotide polymorphism (SNP), rs402710, located in 5p15.33, was firstly identified to be associated with the lung cancer risk in a genome-wide association study. However, some following replication studies yielded inconsistent results.

Methodology and Findings

A case-control study of 611 cases and 1062 controls in a Chinese population was conducted, and then a meta-analysis integrating the current and previously published studies with a total 31811 cases and 36333 controls was performed to explore the real effect of rs402710 on lung cancer susceptibility. Significant associations between the SNP rs402710 and lung cancer risk were observed in both case-control study and meta-analysis, with ORs equal to 0.77 (95%CI = 0.63–0.95) and 0.83 (95%CI = 0.81–0.86) in dominant model, respectively. By stratified analysis of our case-control study, the associations were also observed in never smoker group and non-small cell lung cancer(NSCLC) group with ORs equal to 0.71 (95%CI = 0.53–0.95) and 0.69 (95%CI = 0.55–0.87), which was remarkable that larger effect of the minor allele T was seen in the two groups than that in overall lung cancer. Besides, the sensitive and cumulative analysis indicated the robust stability of the current results of meta-analysis.

Conclusion

The results from our replication study and the meta-analysis provided firm evidence that rs402710 T allele significantly contributed to decreased lung cancer risk, and the case-control study implied that the variant may yield stronger effect on NSCLC and never smokers. However, the mechanism underlying the polymorphism conferring susceptibility to lung cancer is warranted to clarify in the follow-up studies.

HLA class II associated with outcomes of hepatitis B and C infections

Several factors influence the clinical course of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. The human leukocyte antigen (HLA) system, the major histocompatibility complex (MHC) in humans, has been considered one of the most important host factors with respect to outcomes. To date, conventional genotyping studies have shown that HLA class II loci are mainly associated with spontaneous clearance of HBV and HCV. However, the specific HLA locus associated with the outcomes of hepatitis virus infection remains unclear. A recent genome-wide association study (GWAS) using a comprehensive approach for human genotyping demonstrated single nucleotide polymorphisms (SNPs) associated with the outcomes of hepatitis virus infection. Examination of large numbers of cohorts revealed that several SNPs in both HLA-DPA1 and HLA-DPB1 loci are associated with persistent HBV infection in Asian populations. To date, however, few studies have focused on HLA-DP because polymorphisms of HLA-DP haplotype do not vary greatly as compared with other loci of HLA. There are not enough studies to reveal the function of HLA-DP. GWAS additionally detected candidate SNPs within HLA loci associated with chronic HBV or HCV hepatitis, hepatic fibrosis, and the development of hepatocellular carcinoma. The results of one cohort were not always consistent with those of other cohorts. To solve several controversial issues, it is necessary to validate reported SNPs on HLA loci in global populations and to elucidate the HLA-allele-regulated molecular response to hepatitis virus infection.

Association of interferon-gamma induced protein 10 promoter polymorphisms with the disease progression of hepatitis B virus infection in Chinese Han population

Background and Aims

Interferon-gamma induced protein 10 (IP-10) was suggested to be involved in liver injury in viral hepatitis. This study aimed to investigate the impact of the single nucleotide polymorphisms (SNP) G-201A (rs1439490) in IP-10 gene on disease progression of hepatitis B virus (HBV) infection.

Methods

The -201 SNP in IP-10 promoter was genotyped from 577 patients with different illness categories and 275 health controls; In vitro IP-10 promoter activity was compared between haplotype GG and AA homozygotes using luciferase reporter system in HepG2 cells. In vivo expression of IP-10 was compared between patients with -201 AA genotype and GG genotype.

Results

The detected frequency of G-201A SNP was 17.8%, 25.3%, 26.6%, and 13.8% for patients with acute hepatitis B (AHB), patients with mild chronic hepatitis B (CHB-M), patients with severe chronic hepatitis B (CHB-S), and health controls, respectively. In vitro IP-10 promoter-driven luciferase activity in pGL3-Enhancer-201A transfected HepG2 cells was 1.43-fold higher than that in pGL3-Enhancer-201G transfected HepG2 cells (P<0.01). In vivo IP-10 transcriptional expression of peripheral blood mononuclear cells was 1.38-fold higher in patients with -201 AA genotype than in patients with -201 GG genotype (P<0.01).

Conclusion

G-201A in promoter region of IP-10 gene was associated with liver disease progression in patients with HBV infection through up-regulating IP-10 expression.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Public awareness of three major infectious diseases in rural Zhejiang province, China: a cross-sectional study

BACKGROUND

This study aimed to investigate the level of awareness of and factors associated with major infectious diseases in rural China and to provide the most recent baseline data for the prevention and control of these diseases.

METHODS

This cross-sectional study was carried out in Zhejiang province between December 2010 and April 2011. Participants were recruited from 36 villages and interviewed by doctors from the community health service using a structured questionnaire.

RESULTS

The study sample consisted of 36,377 subjects aged 15 to 80 years old. Study results showed that knowledge of HIV was adequate in 44.21% of rural residents; knowledge of TB was adequate in 52.66% of respondents; and knowledge of HBV was adequate in 60.18% of respondents. People in older age groups and with lower education levels were more likely to have low levels of awareness of these three infectious diseases. Participants in the farming industry had poorer awareness of HIV and HBV, while students and factory workers knew little of TB. The proportions of people reporting being fully satisfied with the control policies for HIV, TB and HBV were 37.70%, 34.25% and 36.12%, respectively.

CONCLUSIONS

The level of awareness of HIV, TB and HBV is still low among rural residents. Further national disease control plans for major infectious diseases should emphasise effective and comprehensive health education campaigns to increase public awareness of these diseases in rural areas of China.

Association between Interferon-Inducible Protein 6 (IFI6) Polymorphisms and Hepatitis B Virus Clearance

CD8+ T cells are key factors mediating hepatitis B virus (HBV) clearance. However, these cells are killed through HBV-induced apoptosis during the antigen-presenting period in HBV-induced chronic liver disease (CLD) patients. Interferon-inducible protein 6 (IFI6) delays type I interferon-induced apoptosis in cells. We hypothesized that single nucleotide polymorphisms (SNPs) in the IFI6 could affect the chronicity of CLD. The present study included a discovery stage, in which 195 CLD patients, including chronic hepatitis B (HEP) and cirrhosis patients and 107 spontaneous recovery (SR) controls, were analyzed. The genotype distributions of rs2808426 (C > T) and rs10902662 (C > T) were significantly different between the SR and HEP groups (odds ratio [OR], 6.60; 95% confidence interval [CI], 1.64 to 26.52, p = 0.008 for both SNPs) and between the SR and CLD groups (OR, 4.38; 95% CI, 1.25 to 15.26; p = 0.021 and OR, 4.12; 95% CI, 1.18 to 14.44; p = 0.027, respectively). The distribution of diplotypes that contained these SNPs was significantly different between the SR and HEP groups (OR, 6.58; 95% CI, 1.63 to 25.59; p = 0.008 and OR, 0.15; 95% CI, 0.04 to 0.61; p = 0.008, respectively) and between the SR and CLD groups (OR, 4.38; 95% CI, 1.25 to 15.26; p = 0.021 and OR, 4.12; 95% CI, 1.18 to 14.44; p = 0.027, respectively). We were unable to replicate the association shown by secondary enrolled samples. A large-scale validation study should be performed to confirm the association between IFI6 and HBV clearance.

Host genetic factors affecting spontaneous HBsAg seroclearance in chronic hepatitis B patients

Spontaneous clearance of hepatitis B surface antigen (HBsAg) in chronic hepatitis B (CHB) patients usually indicates a remission of hepatitis activity and a favorable outcome. Two single nucleotide polymorphisms (SNP), rs3077 near HLA-DPA1 region and rs9277535 near HLA-DPB1 region, have been shown to be associated with HBV persistence after acute HBV infection. However, little is known about the impact of these 2 SNPs on spontaneous HBsAg clearance in CHB patients. In this case-control study, a total of 100 male HBeAg-negative chronic HBV carriers who cleared HBsAg spontaneously (case group) and 100 age-matched HBeAg-negative male patients with persistent HBsAg positivity (control group) were enrolled. We investigated the relationship between these 2 SNPs and HBsAg clearance. There was a higher frequency of rs9277535 non-GG genotype in the case group (57% vs. 42%). Patients with rs9277535 non-GG genotype had a higher chance to clear HBsAg [Odds ratio (OR): 1.83, 95% confidence interval (CI): 1.04∼3.21, P = 0.034]. Compared to GG haplotype of rs3077 and rs9277535, GA haplotype had a higher chance of achieving spontaneous HBsAg loss (OR: 2.17, 95% CI: 1.14∼4.16, P = 0.030). In conclusion, rs9277535 non-GG genotype is associated with a higher likelihood of spontaneous HBsAg seroclearance in CHB patients.

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.

Genome-wide association study confirming association of HLA-DP with protection against chronic hepatitis B and viral clearance in Japanese and Korean

Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85–90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with P_meta = 1.89×10⁻¹² for rs3077 and P_meta = 9.69×10⁻¹⁰ for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (P_meta = 4.40×10⁻¹⁹ for rs3077 and P_meta = 1.28×10⁻¹⁵ for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule.