Infectious disease markers in young blood donors. Retrovirus Epidemiology Donor Study

BACKGROUND: To evaluate whether the active recruitment of young donors of high school and college age could affect the safety of the blood supply, prevalence and incidence rates of infectious disease markers among donors aged 17 to 18 and 19 to 22 were compared to those in donors 23 years of age and older. STUDY DESIGN AND METHODS: Over 15 percent of 4.97 million whole blood donations were collected from donors aged 17 to 18 and 19 to 22. Prevalence (per 100,000 first-time donors) and incidence (per 100,000 person-years) rates for confirmed infectious diseases were compared between age groups. RESULTS: The prevalence estimates for HIV, HCV, HTLV-I and -II, and serologic tests for syphilis (STS) were significantly lower among first-time donors aged 17 to 18 and 19 to 22 than among those 23 to 44 years of age. HBsAg prevalence was higher in the first-time donors in the younger groups than in first-time donors in the older group because of higher prevalences among Asians and blacks. The incidence rates of HIV, HCV, and HTLV were similar in the younger groups and the older group. Donors 19 to 22 years of age had a higher incidence rate of estimated HBV than did donors aged 23 to 44 and 45+ (p<0.001), but the incidence rate of STS was lower in donors aged 17 to 18 and 19 to 22 than in donors 23 to 44 and 45+ years of age (p<0.001). CONCLUSION: Aggressive recruitment of school-age donors should not result in an increased risk of transmission-transmitted infections, with the possible exception of HBV.     

Hemagglutinating virus of Japan protein is efficient for induction of CD4+ T-cell response by a hepatitis B core particle-based HIV vaccine

By using the hepatitis B core (HBc) protein gene as a carrier, HIV-1 env V3 gene was inserted into the carrier gene, and the HIV gene was expressed inside a chimeric HIV-HBc particle (HIV-HBc), which was a unique candidate for induction of HIV-specific CTL activity. This was seen significantly in mice without the need of an adjuvant, because other responses specific for the HIV peptide such as T-cell proliferation and antibody production were not induced. However, when hemagglutinating virus of Japan (HVJ) protein was incorporated into an anionic liposome containing HIV peptide (HIV-HVJ-liposome) and was used as a booster immunization in HIV-HBc primed animals, the HIV-specific T-cell response and enhanced CTL activity were clearly induced in consecutively immunized animals. Furthermore, the HIV-specific humoral immune response was also induced and a neutralization activity was detected in the immune sera. Thus, when an HIV peptide antigen is expressed inside the virus like a particle of HBc, it can induce both cellular and humoral immunities when an HVJ-HIV-liposome, but not an HIV-liposome, is inoculated as the booster antigen. The HVJ-stimulated splenocytes secreted IL-18 and IL-12 to synergistically enhance the secretion of IFN-gamma in vitro. These findings suggest that the HVJ protein is effective at inducing the HIV-specific immunities, if used as part of a booster antigen in the consecutive immunization regimen.     

Localization and reactivity of an immunodominant domain in the NS3 region of hepatitis C virus

Analysis of the amino acid sequences of the non-structural region 3 (NS3) of the hepatitis C virus type 1 revealed four points with a high average hydrophilicity (Ah). Two of these potential anti-genie sites were expressed in E. coli as short fragments. The first fragment of 91 residues (NS3f3: residues 1359–1449) harbors the hexapeptide K-K-K-C-D-E with an Ah of 2.33; the second fragment is 73 residues long (NS3f4: residues 1460–1532) and encompasses the hep-tapeptide R-S-N-R-R-G-R with an Ah of 1.79. Both fragments were expressed with truncated hepatitis B core (tHBc) as a carrier protein. The fusion proteins were purified from the bacterial lysates by affinity chromatography on immobilized monoclonal antibodies against HBc, and evaluated as antigens in an enzyme immunoassay for the detection of HCV antibodies. In a specificity control panel, reactivity with NS3f3 was only found in proven HCV carriers, while reactivity with NS3f4 was weak in HCV carriers but accounted for some of the nonspecific serological reactions. In a group of 48 genotyped HCV-in-fected volunteer blood donors, antibodies against NS3f3 were detected in 90% (27/30) of HCV-type 1 infections and in all HCV-type 4 infections (5/5). However, in carriers infected with HCV-types 2, 3, or 5, the response rate was on average only 23% (3/13). With NS3f4 as antigen, weak antibody titers were found in only about half of the carriers, independent of the infectious genotype. In a cohort of hemodialysis patients, all infected with HCV-type 1b, NS3f3 antibodies were detected in 80% (16/20) of the carriers, while only one patient showed a weak NS3f4 reactivity. It is concluded that NS3f3 harbors an immunodominant domain of the NS3 region showing an apparently HCV-type-dependent serological response. © 1995 Wiley-Liss, Inc.     

Inferior graft survival of hepatitis B core positive grafts is not influenced by post‐transplant hepatitis B infection in liver recipients—A 35‐year single‐center experience

Nonoptimal liver grafts, and among them organs from anti‐HBc+ donors, are increasingly used for liver transplantation. In this retrospective study including 1065 adult liver transplantations performed between 1977 and 2012, we analyzed long‐term patient and graft survival and occurrence of HBV infection. A total of 52 (5.1%) patients received an anti‐HBc+ graft. The 10‐year graft and patient survival of these recipients were 50.9% and 59.0% compared to 72.0% and 76.5% (P = 0.001; P = 0.004) of patients receiving anti‐HBc‐ grafts, respectively. Cox regression model showed that high urgency allocation (P = 0.003), recipient age (P = 0.027), anti‐HCV+ recipients (P = 0.005), and anti‐HBc+ organs (P = 0.048) are associated with decreased graft survival. Thirteen of 52 (25.0%) patients receiving anti‐HBc+ grafts developed post‐transplant HBV infection within a mean of 2.8 years. In this study, antiviral prophylaxis did not have significant impact on HBV infection, but long‐term survival (P = 0.008). Development of post‐transplant HBV infection did not affect adjusted 10‐year graft survival (100% vs. 100%; P = 1). Anti‐HBc+ liver grafts can be transplanted with reasonable but inferior long‐term patient and graft survival. The inferior graft survival is not, however, related with post‐transplant HBV infection as long as early diagnosis and treatment take place.     

以HBc颗粒为呈现载体的真核表达载体pcDNA3.1-HBcNhel的构建

目的构建含乙肝核心C基因的真核表达载体pcDNA3.1-HBcNhel,探索其作为DNA疫苗载体的可能性.方法采用分子克隆技术在原核表达质粒pTrc-core的HBcAg el-loop处添加NheI酶切位点,双酶切此重组载体pTrc-coreNhel及真核表达载体pcDNA3.1,产物经纯化、T4DNA连接酶连接,连接产物转化大肠杆菌DH5α,筛选抗Amp+克隆并提取质粒进行酶切及PCR鉴定.结果成功构建了真核表达质粒pcDNA3.1-HBcNhel.结论该重组质粒可作为治疗性及预防性疫苗的候选载体,为深入研究预防性及治疗性疫苗奠定了基础.     

Can the serological status of “anti‐HBc alone” be considered a sentinel marker for detection of “occult” HBV infection?

Some individuals have "occult" infection with hepatitis B virus (HBV), defined as presence of HBV genome in the serum or liver tissue without HBV surface antigen (HBsAg) in the serum. The aim of this study was to investigate whether serum antibodies against HBV core antigen in isolation ("anti-HBc alone") are a useful marker of "occult" HBV in patients with or without hepatitis C virus (HCV) infection. "Anti-HBc alone" was detected in the sera of 119/6,544 (1.8%) asymptomatic outpatients referred to the diagnostic laboratory for routine testing for viral hepatitis, 62/607 (10.2%) drug users, and 42/195 (21.5%) patients with hepatocellular carcinoma. Using three in-house nested-PCR amplification assays to detect HBV preS-S (S), precore-core (C), and Pol viral regions, respectively, "occult" HBV sequences were found in 9 of the 223 sera (4.0%) with "anti-HBc alone." The highest prevalence of "occult" HBV sequences (5.9%) was detected in "anti-HBV alone" sera of individuals referred to the diagnostic laboratory without HCV antibodies. Direct sequencing of all PCR products confirmed the specificity of the PCR reactions and revealed the predominance of HBV genotype D. The data presented in this study suggest that detection of "anti-HBc alone" could reflect unrecognized "occult" HBV infection and that physicians should consider investigating such patients with HBV molecular tests.     

Isolated core antibody hepatitis B in sub-Saharan African immigrants

Chronic hepatitis B virus (HBV) infection is a major health problem in sub-Saharan Africa, where prevalence is > or =8%, and is increasingly seen in African immigrants to developed countries. A retrospective audit of the medical records of 383 immigrants from sub-Saharan Africa attending the infectious diseases clinics at the Royal Melbourne Hospital was performed from 2003 to 2006. The HBV, human immunodeficiency virus (HIV) and hepatitis C virus (HCV) serological results are reported, with a focus on the isolated core antibody HBV pattern (detection of anti-HBc without detection of HBsAg or anti-HBs). Two-thirds (118/174, 68%) of those tested had evidence of HBV infection with detectable anti-HBc. Chronic HBV infection (serum HBsAg detected) was identified in 38/174 (22%) and resolved HBV infection (both serum anti-HBs and anti-HBc detected) in 45/174 (26%). The isolated core antibody pattern was identified in 35/174 (20%), of whom only 1/35 (3%) had detectable serum HBV DNA on PCR testing, indicating occult chronic HBV (OCHB). Only 8/56 (14%) patients with negative anti-HBc had serological evidence of vaccination (serum anti-HBs detected). HIV infection was detected in 26/223 (12%). HCV antibodies were detected in 10/241 (4%), of whom 8 (80%) had detectable HCV RNA. Viral co-infection was detected in only 2/131 (1.5%) patients tested for all three viruses. The isolated core antibody HBV pattern was common among sub-Saharan African patients in our study. These patients require assessment for OCHB infection and monitoring for complications of HBV.     

Frequent detection of hepatitis B virus DNA in hepatocellular carcinoma of patients with sustained virologic response for hepatitis C virus

Hepatocellular carcinoma (HCC) develops several years after the eradication of hepatitis C virus (HCV) by interferon therapy. Risk factors for the development of HCC are only partly understood. To elucidate the role of occult hepatitis B virus (HBV) infection in hepatocarcinogenesis in patients with sustained virologic response, the prevalences of HBV‐related makers were examined. Study group comprised 16 patients with sustained virologic response (group A) and 50 with HCV (group B). Anti‐HBc and anti‐HBs in serum were examined by enzyme‐linked immunoassay. HBV DNA in liver was examined by nested polymerase chain reaction, using primers specific for genes encoding for HBx, HBsAg, HBcAg, and HBV cccDNA. Sequence of the amplified HBV DNA for ‘a’ determinant of HBsAg was determined in HCC. Anti‐HBc was positive in 10 of 16 in group A and 25 of 50 in group B. HBV DNA in liver was detected in 12 of 16 in group A and 21 of 50 in group B (P = 0.044). In group A, HBV DNA in liver was detected frequently in patients without cirrhosis and in those with a longer period from the time of HCV eradication to the development of HCC. Mutation in ‘a’ determinant of HBsAg was found in three HCC of group A. Occult HBV infection may be one of the most important risk factors in hepatocarcinogenesis of Japanese patients with sustained virologic response. J. Med. Virol. 81:1009–1014, 2009. © 2009 Wiley‐Liss, Inc.     

The position of Spy Tag/Catcher system in hepatitis B core protein particles affects the immunogenicity and stability of the synthetic vaccine

Presenting exogenous antigens on virus-like particles (VLPs) through “plug-and-display” decoration strategies based on SpyTag/SpyCatcher isopeptide bonding have emerged as attractive technology for vaccine synthesis. However, whether the position of ligation site in VLPs will impose effects on immunogenicity and physiochemical properties of the synthetic vaccine remains rarely investigated. Here in the present work, the well-established hepatitis B core (HBc) protein was used as chassis to construct dual-antigen influenza nanovaccines, with the conserved epitope peptides derived from extracellular domain of matrix protein M2 (M2e) and hemagglutinin (HA) as target antigens. The M2e antigen was genetically fused to the HBc in the MIR region, together with the SpyTag peptide, which was fused either in the MIR region or at the N-terminal of the protein, so that a recombinant HA antigen (rHA) linked to SpyCatcher can be displayed on it, at two different localizations. Both synthetic nanovaccines showed ability in inducing strong M2e and rHA-specific antibodies and cellular immunogenicity; nevertheless, the one in which rHA was conjugated by N-terminal Tag ligation, was superior to another one synthesized by linking the rHA to MIR region SpyTagged-HBc in all aspects, including higher antigen-specific immunogenicity responses, lower anti-HBc carrier antibody, as well as better dispersion stability. Surface charge and hydrophobicity properties of the two synthetic nanovaccines were analyzed, results revealed that linking the rHA to MIR region SpyTagged-HBc lead to more significant and disadvantageous alteration in physiochemical properties of the HBc chassis. This study will expand our knowledge on “plug-and-display” decoration strategies and provide helpful guidance for the rational design of HBc-VLPs based modular vaccines by using SpyTag/Catcher synthesis.     

Persistent and transient hepatitis B virus (HBV) infections in children born to HBV‐infected mothers despite active and passive vaccination

Summary. Combined passive and active immunization for newborns very effectively prevents perinatal hepatitis B virus (HBV) infections. In the Netherlands, babies born to hepatitis B surface antigen (HBsAg)‐positive women receive passive immunization with hepatitis B and at least three active HBsAg vaccinations. Serological testing for the presence of HBV markers was offered for all infants born to HBsAg‐positive mothers between January 2003 and July 2007, after completion of their vaccination schedule. About 75% of the infants (n = 1743) completed their HB‐vaccination schedule and participated in the serologic evaluation. Twelve of them (0.7%) were found to be HBV infected. Furthermore, we identified three older children with high levels of anti‐HBc, anti‐HBs and anti‐HBe, while they were HBsAg and HBV DNA negative. This serologic profile is evidence for a resolved HBV infection. In the group of older children (1.5–5 years of age, n = 728), about half of the HBV‐infected children (3 of 7) had already cleared their infection at the time of sampling. For a proper evaluation of the efficacy of a new intervention programme to prevent vertical HBV transmission, it is also important to analyse the HBV markers in serum collected when the children are older than 1.5 years. In a programmatic setting, all children born to HBV‐infected mothers should be tested not only for the level of anti‐HBs but also for the absence of HBsAg, because 2 of the 12 HBV‐infected children (17%) had a high level of anti‐HBs.