Association of variants in HLA-DP on chromosome 6 with chronic hepatitis B virus infection and related phenotypes

Hepatitis B virus (HBV) infection affects more than 2 billion people throughout the world. Among them, more than 240 million have chronic infection. Every year, 0.5–1.2 million people die of chronic hepatitis B virus infection (CHBVI), and approximately 60 % of liver cancers are related to CHBI and subsequent liver cirrhosis (LC). These HBVI-related diseases impose a considerable economic burden as well as morbidity on patients, families, and society. Family and twin studies have indicated that the host genetic constitution greatly influences the clinical outcomes of HBV infection. During the past several years, genome-wide association studies (GWAS) have identified susceptibility variants for various HBVI-related diseases. Of these variants, SNPs rs3077 and rs9277535 in HLA-DP on chromosome 6 show the strongest evidence for association with CHBVI and with viral clearance. However, whether there exists an association between HLA-DP variants and the progression of CHBVI remains to be determined. Thus, further study should focus not only on identifying more variants in HLA-DP that are associated with various HBVI-related diseases but also on characterizing any newly discovered functional variants at the molecular level. Further, given the complexity of CHBV infection and its progression, gene–gene and gene–environment interactions should also be taken into consideration. Moreover, because both smoking and alcohol affect HBV infection and progression, it is important to understand how these factors interact with genetics to influence HBV-related diseases.     

KIR and HLA loci are associated with hepatocellular carcinoma development in patients with hepatitis B virus infection: a case-control study

Background

Natural killer (NK) cells activation has been reported to contribute to inflammation and liver injury during hepatitis B virus (HBV) infection both in transgenic mice and in patients. However, the role of NK cells in the process of HBV-associated hepatocellular carcinoma (HCC) development has not been addressed. Killer cell immunoglobulin-like receptors (KIRs) are involved in regulating NK cell activation through recognition of specific human leukocyte antigen (HLA) class I allotypes.

Methodology/Principal Findings

To investigate whether KIR and HLA genes could influence the risk of HBV-associated HCC development, 144 HBV-infected patients with HCC and 189 well-matched HBV infectors with chronic hepatitis or cirrhosis as non-HCC controls were enrolled in this study. The presence of 12 loci of KIR was detected individually. HLA-A, -B, -C loci were genotyped with high-resolution. HLA-C group 1 homozygote (OR = 2.02; p = 0.005), HLA-Bw4-80I (OR = 2.67; p = 2.0E-04) and combination of full-length form and 22 bp-deleted form of KIR2DS4 (KIR2DS4/1D) (OR = 1.89; p = 0.017) were found associated with HCC incidence. When the combined effects of these three genetic factors were evaluated, more risk factors were observed correlating with higher odds ratios for HCC incidence (P trend = 7.4E-05). Because all the risk factors we found have been reported to result in high NK cell functional potential by previous studies, our observations suggest that NK cell activation may contribute to HBV-associated HCC development.

Conclusions/Significance

In conclusion, this study has identified significant associations that suggest an important role for NK cells in HCC incidence in HBV-infected patients. Our study is useful for HCC surveillance and has implications for novel personalized therapy strategy development aiming at HCC prevention in HBV-infected patients.     

Epidemiologic features of hepatitis B virus infection in northern Labrador.

We studied the epidemiologic features of hepatitis B virus (HBV) infection in northern Labrador to determine the prevalence of the infection and to obtain a database to develop a vaccination strategy. The study population included seven communities in which five ethnic groups were represented: Inuit, Innu, mixed Inuit and European ancestry ("settler"), nonnative/nonsettler transient population ("white") and people of Innu-white or Innu-Inuit origin ("mixed"). Blood samples from 2156 people (62% of the area residents) were tested for antibody to HBV core antigen (anti-HBc), HBV surface antigen (HBsAg), HBV e antigen (HBeAg), anti-HBc IgM and antibody to the surface antigen (anti-HBs). The overall crude prevalence rate of HBV seromarkers was 14.7% and the HBsAg carrier rate at least 3.2%; the rates were highest for Inuit (26.4% and 6.9% respectively), followed by settler (10.0% and 1.9% respectively) and Innu (7.6% and 0.4% respectively); the white and mixed groups had the lowest overall rates (2.5% and 3.3% respectively). Although the overall prevalence rates were about the same for the two sexes, the HBsAg carrier rate was higher in males (male:female ratio 1.6:1.0). No HBV carriers were positive for HBeAg or anti-HBc IgM antibody. The rate of exposure to HBV was 4% for those below the age of 20 years and reached a peak for those aged 45 to 54 years (85% for Inuit, 40% for settlers and 37% for Innu). There was also a wide variation in the age-standardized prevalence rates (0% to 27.9%) among the ethnic groups in the seven communities surveyed.     

Effects of interaction between genetic variants in human leukocyte antigen DQ and granulysin genes in Chinese Han subjects infected with hepatitis B virus

Single nucleotide polymorphisms (SNPs) of HLA‐DQ and granulysin (GNLY) are reportedly associated with HBV infection. The aim of this study was to investigate the effects of interactions between SNPs in HLA‐DQ and GNLY on the outcome of hepatitis B virus (HBV) infection in Chinese Han subjects. HLA‐DQ (rs9275572) and GNLY (rs1866139 and rs11127) were genotyped in 310 subjects with HBV‐related chronic liver disease, 295 in whom spontaneous clearance of HBV had occurred and 316 who had not been exposed to HBV. HLA‐DQ rs9275572 was significantly correlated with HBV clearance (dominant genetic model: OR, 1.84; 95% CI, 1.30–2.61; adjusted P = 0.001). There was no statistical association of GNLY rs1866139 and rs11127with HBV infection outcomes. However, significant sex‐specific associations with HBV susceptibility were observed in men who carried rs1866139 CG or rs11127 TC and in women who carried rs1866139 GG or rs11127 CC. The findings were the same in the validation cohort, which was composed of 829 subjects. Based on a multifactor dimensionality reduction test with permutation correction, a three‐way interaction between SNPs in HLA‐DQ and GNLY was identified in terms of HBV clearance. In conclusion, additional evidence for an association of HLA‐DQ and GNLY SNPs with HBV infection outcomes has been identified and a SNP‐SNP interaction between HLA‐DQ and GNLY on HBV clearance observed.     

Immunology of hepatitis B virus and hepatitis C virus infection

More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and survival strategies. This review assesses recent advances in our understanding of viral hepatitis, contrasts mechanisms of virus-host interaction in acute hepatitis B and hepatitis C, and outlines areas for future studies.     

Association of common variants in KIF21B and ankylosing spondylitis in a Chinese Han population: a replication study

KIF21B polymorphisms were found associated with susceptibility to multiple sclerosis and ankylosing spondylitis (AS) in populations of white European ancestry. We aimed to replicate the association of polymorphisms around KIF21B and AS in a Chinese Han population. This case–control study included 665 patients with AS and 1,042 healthy controls genotyped for seven single nucleotide polymorphisms (SNPs) of KIF21B—rs12118246, rs4915464, rs502658, rs10494829, rs12089839, rs6687260, and rs957957—by TaqMan genotyping assay; statistical analyses involved the use of PLINK. We also estimated the linkage disequilibrium and haplotypes of these SNPs. Two SNPs—rs502658 (allelic p?=?0.0002, odds ratio [OR] 0.60, 95 % confidence interval [95 % CI] 0.47–0.76) and rs10494829 (allelic p?=?0.003, OR 1.30, 95 % CI 1.12–1.52)—were significantly associated with AS in the Chinese Han population. In addition, a linear regression test showed that they have independent contribution to disease susceptibility. For both SNPs, haplotype AT was strongly associated with AS and increased the risk of the disease (p?=?0.045, OR 1.183, 95 % CI 1.004–1.395), and the genotype GC reduced the risk (p?=?0.011, OR 0.715, 95 % CI 0.55–0.928). This work identified a significant association of two SNPs in KIF21B and AS in the Chinese Han population. KIF21B may play an important role in the pathogenesis of AS in the Chinese population and might be a new therapeutic target for AS.     

Antiviral immunity following smallpox virus infection: a case-control study

Outbreaks of smallpox (i.e., caused by variola virus) resulted in up to 30% mortality, but those who survived smallpox infection were regarded as immune for life. Early studies described the levels of neutralizing antibodies induced after infection, but smallpox was eradicated before contemporary methods for quantifying T-cell memory were developed. To better understand the levels and duration of immunity after smallpox infection, we performed a case-control study comparing antiviral CD4(+) and CD8(+) T-cell responses and neutralizing antibody levels of 24 smallpox survivors with the antiviral immunity observed in 60 smallpox-vaccinated (i.e., vaccinia virus-immune) control subjects. We found that the duration of immunity following smallpox infection was remarkably similar to that observed after smallpox vaccination, with antiviral T-cell responses that declined slowly over time and antiviral antibody responses that remained stable for decades after recovery from infection. These results indicate that severe, potentially life-threatening disease is not required for the development of sustainable long-term immunity. This study shows that the levels of immunity induced following smallpox vaccination are comparable in magnitude to that achieved through natural variola virus infection, and this may explain the notable success of vaccination in eradicating smallpox, one of the world's most lethal diseases.     

2型糖尿病患者乙型肝炎病毒感染率分析

目的：通过调查糖尿病患者乙型肝炎病毒（HBV）的携带率,阐明糖尿病发生是否与HBV感染有关,并观察糖尿病合并HBV感染时是否加重对肝功能的损害。方法：用ELISA方法检测533例2型糖糖尿病患者和1440例普通人群乙型肝炎表面抗原（HBsAg）以及HBV其他血清学标志,同时常规测定肝功能和血糖等。结果：2型糖尿病HBsAg阳性24例,阳性率4.50%,普通人群HBsAg阳性70例,阳性率4.86%,两组间阳性率差异无统计学意义（x2=0.110,P=0.740）。糖尿病患者感染HBV后的抗体应答与普通人群相似。糖尿病合并HBV感染者与无糖尿病HBV感染者的肝功能异常差异无统计学意义。糖尿病患者中83例（16.3%）谷氨酰转肽酶升高,在肝功能异常指标中最常见,这与HBV感染后丙氨酸转氨酶升高为主不同。结论：糖尿病发生与HBV感染无关,糖尿病合并HBV感染时不加重对肝脏的损害。     

Effect of concurrent acute infection with hepatitis C virus on acute hepatitis B virus infection.

OBJECTIVE--To investigate the possible interference with acute hepatitis B virus infection by co-infection with hepatitis C virus. DESIGN--Analysis of stored sera collected for transfusion transmitted viruses study in 1970s. SETTING--Four major medical centres in the United States. PATIENTS--12 recipients of blood infected with hepatitis B virus. MAIN OUTCOME MEASURES--In 1970s, presence of antibodies in hepatitis B virus and raised serum alanine aminotransferase concentration; detection of antibodies to hepatitis C virus with new enzyme linked immunoassays. RESULTS--Five of the 12 patients were coinfected with hepatitis C virus. Hepatitis B surface antigen was first detected at day 59 in patients infected with hepatitis B virus alone and at day 97 in those coinfected with hepatitis C virus (p = 0.01); median durations of antigenaemia were 83 and 21 days respectively (p = 0.05), and the antigen concentration was lower in the coinfected patients. Alanine aminotransferase patterns were uniphasic when hepatitis B virus infection occurred alone (range 479-2465 IU/l) and biphasic in patients with combined acute infection (no value > 380 IU/l; p = 0.0025). Four coinfected recipients developed chronic hepatitis C virus infection. The fifth patient was followed for only four months. CONCLUSIONS--Acute coinfection with hepatitis C virus and hepatitis B virus inhibits hepatitis B virus infection in humans, and onset of hepatitis B may reduce the severity of hepatitis C virus infection but not frequency of chronicity. Alanine aminotransferase concentration showed a biphasic pattern in dual infection.     

Animal models for the study of hepatitis B virus infection

Even with an effective vaccine, an estimated 240 million people are chronically infected with hepatitis B virus(HBV) worldwide. Current antiviral therapies,including interferon and nucleot(s)ide analogues,rarely cure chronic hepatitis B. Animal models are very crucial for understanding the pathogenesis of chronic hepatitis B and developing new therapeutic drugs or strategies. HBV can only infect humans and chimpanzees, with the use of chimpanzees in HBV research strongly restricted. Thus, most advances in HBV research have been gained using mouse models with HBV replication or infection or models with HBV-related hepadnaviral infection. This review summarizes the animal models currently available for the study of HBV infection.     

Genetic variants in the microRNA machinery gene GEMIN4 are associated with risk of prostate cancer: a case-control study of the Chinese Han population

Single-nucleotide polymorphisms located in the microRNA biogenesis pathway could alter the risk for developing prostate cancer. The present study was intended to identify common genetic variants responsible for prostate cancer susceptibility in the GEMIN4 gene. The high-resolution melting method was used to genotype seven polymorphisms (rs7813, rs4968104, rs3744741, rs2740348, rs1062923, rs910925, and rs910924) in the GEMIN4 gene in 300 prostate cancer patients and 244 matched controls. The encouraging discovery in this study was in the rs2740348. Patients carrying the variant heterozygote GC genotype in the rs2740348 were at a 36% decreased risk of prostate cancer (odds ratio [OR] = 0.64; 95% confidence interval [CI] = 0.42, 0.99). Similarly, this variant allele carrier showed significant risk for prostate cancer (OR = 0.64). In addition, subjects carrying the homozygote TT genotype in the rs7813 had a significantly increased risk of prostate cancer (OR = 2.53, 95% CI = 1.07, 6.28). Two common haplotypes were found to be associated with decreased risk of prostate cancer. In the subgroup analysis, higher risk of more severity of prostate cancer (clinical stage III and IV) was observed in individuals with the rs7813 TT genotype (OR = 2.64, 95% CI = 1.02, 7.64), while lower risk of more severity of prostate cancer was observed in individuals with the rs3744741 T allele (OR = 0.69, 95% CI = 0.50, 0.96). Overall, our study provides substantial support for the association between the GEMIN4 gene and the risk of prostate cancer.     

Association of TNF-alpha genetic polymorphisms with hepatocellular carcinoma susceptibility: a case-control study in a Han Chinese population

The single nucleotide polymorphisms (SNPs) within the tumor necrosis factor-a (TNF-a) gene promoter region have been reported to be associated with susceptibility to various types of cancers. A case-control study (126 hepatocellular carcinoma [HCC] patients and 126 normal controls) was conducted to elucidate their possible association with the risk of hepatitis B virus (HBV)-related HCC in a Han Chinese population. TNF-alpha polymorphisms -1031T/C, -863C/A, -857C/T, -308G/A, and -238G/A were genotyped by polymerase chain reaction (PCR) and direct DNA sequencing. Disease associations were analyzed by the chi-square test or Fisher's exact test. When analyzed by overall groups, no significant differences in genotype and allele distributions were observed between the control and cases. However, stratified analysis according to sex showed that the frequency of the homozygous C allele of the -857 polymorphism was lower in female cases than in female controls (62.9% vs. 88.9%, p=0.026). In addition, further haplotype analysis revealed that the TCCGA (-1031/-863/-857/-308/-238) was more frequent in controls than cases (p=0.018; odds ratio = 0.266; 95% confidence interval, 0.083-0.857). These results indicated that the TNF-alpha-857C/T polymorphism may modify HBV-related HCC risk among women, and the haplotype TCCGA (-1031/-863/-857/-308/-238) may account for a decreased susceptibility to HCC development in the Han Chinese population. Additional studies in patients with different ethnic backgrounds are needed to validate these finding and to further explore the genetic pathogenesis of HBV-related HCC.     

Detection of hepatitis B virus in bone allografts from donors with occult hepatitis B infection

The implementation of nucleic acid testing in donor screening has improved the safety of tissue allografts. Although infectious disease transmission can be considered a rare event, the detection of occult hepatitis B infection remains challenging. The studies concerning this risk are mainly based on testing blood specimens. This work shows the correlation between results of samples obtained from donor blood and the corresponding tissue washing solution. Hepatitis B virus deoxyribonucleic acid was detected both in bone allografts from donors with serological profiles associated to active hepatitis B infection and occult hepatitis B infection. These results suggest that hepatitis B virus seems to concentrate in bone marrow even when a low viral load is present in peripheral blood. Even detection at molecular level is not enough to avoid the risk of hepatitis B virus transmission and a multiparametrical evaluation is required in tissue donor screening. The role of clinicians in recognition and reporting of allograft-associated infections is a major concern for the acquisition of experience to be applied in risk control of disease transmission.     

Molecular epidemiology of hepatitis B virus variants in nonhuman primates

We characterized hepatitis B virus (HBV) isolates from sera of 21 hepatitis B virus surface antigen-positive apes, members of the families Pongidae and Hylobatidae (19 gibbon spp., 1 chimpanzee, and 1 gorilla). Sera originate from German, French, Thai, and Vietnamese primate-keeping institutions. To estimate the phylogenetic relationships, we sequenced two genomic regions, one located within the pre-S1/pre-S2 region and one including parts of the polymerase and the X protein open reading frames. By comparison with published human and ape HBV isolates, the sequences could be classified into six genomic groups. Four of these represented new genomic groups of gibbon HBV variants. The gorilla HBV isolate was distantly related to the chimpanzee isolate described previously. To confirm these findings, the complete HBV genome from representatives of each genomic group was sequenced. The HBV isolates from gibbons living in different regions of Thailand and Vietnam could be classified into four different phylogenetically distinct genomic groups. The same genomic groups were found in animals from European zoos. Therefore, the HBV infections of these apes might have been introduced into European primate-keeping facilities by direct import of already infected animals from different regions in Thailand. Taken together, our data suggest that HBV infections are indigenous in the different apes. One event involving transmission between human and nonhuman primates in the Old World of a common ancestor of human HBV genotypes A to E and the ape HBV variants might have occurred.     

Non-B hepatitis in Melbourne: a serological study of hepatitis A virus infection.

A study was performed to establish the value of immune adherence haemagglutination tests for antibody to hepatitis A virus in the diagnosis of non-B hepatitis. Infection with hepatitis A virus was confirmed in 14 out of 16 patients from six families and seven out of nine patients in whom the source of infection was unknown. One additional patient, who had had two episodes of jaundice, was shown to have had an attack of hepatitis A followed by an attack of hepatitis B. In patients with acute hepatitis A antibody detectable by immune adherence haemagglutination becomes detectable three or four weeks after the onset of symptoms and reaches peak levels about five weeks later.