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Chronic Carriers (chronic + carrier)
Selected AbstractsSuccessful clearance of hepatitis B virus after allogeneic stem cell transplantation: beneficial combination of adoptive immunity transfer and lamivudineEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 3 2003Tetsuhiro Chiba Abstract: We report a 38-yr-old male with acute lymphocytic leukemia (ALL), whose serological tests for the hepatitis B virus (HBV) before transplantation showed a chronic carrier status, and a liver biopsy specimen revealed chronic liver injury because of HBV. The patient underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from his sibling who was hepatitis B surface antibody (HBsAb) positive. He had received lamivudine treatment for the prophylaxis of HBV reactivation during cytotoxic chemotherapy, and lamivudine administration continued after transplantation. Successful engraftment was documented 3 wk after PBSCT, and clearance of the hepatitis B surface antigen (HBsAg) was observed 2 months after PBSCT. Liver function tests transiently showed a mild elevation of aminotransferases on day 25, although this returned to normal after the dose escalation of the immunosuppressive agent. We presume that the combination of adoptive immunity transfer by bone marrow transplantation (BMT) from an HBsAb-positive donor and antiviral drugs such as lamivudine is beneficial in clearing HBV in chronic carriers. [source] Virion half-life in chronic hepatitis B infection is strongly correlated with levels of viremia,HEPATOLOGY, Issue 4 2008Maura Dandri Analysis of hepatitis B virus (HBV) kinetics with mathematical models may disclose new aspects of HBV infection and host response mechanisms. To determine the kinetics of virion decay from the blood of patients in different phases of chronic infection, we applied mathematical modeling to real-time polymerase chain reaction assays, which enable quantification of viremia and intrahepatic HBV productivity by measuring both copy number and activity of covalently closed circular DNA (relaxed circular DNA/covalently closed circular DNA) in the liver of 80 untreated chronically active HBV carriers (38 hepatitis B e antigen [HBeAg]-positive and 42 HBeAg-negative individuals). We found that the half-life of circulating virions is very fast (median 46 and 2.5 minutes in HBeAg-positive and HBeAg-negative individuals, respectively) and strongly related to viremia, with clearance rates significantly accelerating as viral loads decrease. To investigate whether immune components can influence the kinetics of virion decay, we analyzed viral dynamics in immunodeficient urokinase-type plasminogen activator chimera mice. Virion half-life in mice (range, 44 minutes to >4 hours) was comparable to estimates determined in high viremic carriers, implying that clearance rates in these patients are mostly determined by common nonspecific mechanisms. Notably, the lack of correlation between virion half-life and viremia in mice indicated that immune components significantly accelerate virion clearance rates in individuals with low titers. Conclusion: Our analyses suggest that both host defense mechanisms and levels of circulating virions affect the kinetics of HBV decay assessed in the serum of chronic carriers. Identification of the factors affecting clearance rates will be important for future antiviral drug developments and it may give insights into the mechanisms involved in clearance of other chronic infections, such as human immunodeficiency virus and hepatitis C virus. (HEPATOLOGY 2008.) [source] Evolving clinical landscape of chronic hepatitis B: A multicenter Italian studyJOURNAL OF MEDICAL VIROLOGY, Issue 12 2009Tommaso Stroffolini Abstract The aim of the study was to evaluate the characteristics of chronic hepatitis B with special reference to the geographical origin of the patients and to the prevalence of HBeAg and viral and non-viral co-factors of liver disease. A cross-sectional multicenter survey was undertaken, which enrolled 1,386 HBsAg chronic carriers observed consecutively in 21 referral centers over a 6-month period. The prevalence of HBeAg in patients was 11%; the presence of HBeAg was associated independently with a younger age and co-infection with HIV. Anti-HDV, anti-HCV, or anti-HIV antibodies were detected in 8.1%, 6.5%, and 2%, respectively. However, among the patients first diagnosed during the study period (incident cases), 14.3% were anti-HDV positive. Seven percent of the patients were immigrants; they were younger than Italian patients and 18% were HBeAg positive; no difference was observed in the prevalence of anti-HDV, anti-HCV, or anti-HIV antibodies. The presence of cirrhosis was associated independently with an age >52 years, the presence of anti-HDV or anti-HCV, alcohol use >4 drinks/day, and a high BMI. The clinical epidemiology of chronic hepatitis B virus (HBV) infection shows a dynamic profile, with the potential for re-emergence of cases with HBeAg or anti-HDV and an emerging impact of metabolic factors on the evolution of liver disease. J. Med. Virol. 81:1999,2006, 2009. © 2009 Wiley-Liss, Inc. [source] Hepatitis D outbreak among children in a hepatitis B hyper-endemic settlement in GreenlandJOURNAL OF VIRAL HEPATITIS, Issue 3 2010M. L. Børresen Summary., Hepatitis B virus (HBV) infection is endemic in Greenland with 5,10% of the population being HBsAg-positive (chronic carriers). Surprisingly, despite of the high prevalence of HBV infection, acute and chronic hepatitis B, liver cirrhosis and primary hepatocellular carcinoma appear much less frequently than expected. The reasons for the low frequencies are unknown, but as a consequence implementation of a childhood HBV vaccination programme, though debated for years, has never been instituted. We describe an outbreak of hepatitis D (HDV) infection among children in a hepatitis B hyper-endemic settlement of 133 inhabitants on the west coast of Greenland. In 2006 a total of 27% of the inhabitants were HBsAg-positive (chronic carriers) and 83% were HBcAb-positive (previously exposed). Forty-six percent of the HBsAg-positive persons were below 20 years of age. On follow-up 1 year later a total of 68% of the HBsAg-positive persons were HDV-IgG positive. Five children, who were HBsAg-positive in 2006, had HDV-seroconverted from 2006 to 2007, indicating a HDV-super-infection. Most of the HDV-IgG positive children had markedly elevated liver enzymes. In the multivariate analysis, among the HBV and HDV markers, presence of HDV-IgG was most strongly associated with elevation of liver enzymes. In conclusion, the HBV-HDV super-infection and presumed HDV outbreak in this settlement challenges the notion that HBV infection may not be as harmless in Greenland as previously anticipated. The findings strongly suggest that HBV vaccination should be included in the child-immunization program in Greenland. [source] HCV-specific T-cell responses in injecting drug users: evidence for previous exposure to HCV and a role for CD4+ T cells focussing on nonstructural proteins in viral clearanceJOURNAL OF VIRAL HEPATITIS, Issue 6 2008T. A. Ruys Summary., In order to understand the parameters associated with resolved hepatitis C virus (HCV)-infection, we analysed the HCV-specific T-cell responses longitudinally in 13 injecting drug-users (IDUs) with a prospectively identified acute HCV infection. Seven IDUs cleared HCV and six IDUs remained chronically infected. T-cell responses were followed in the period needed to resolve and a comparable time span in chronic carriers. Ex vivo T-cell responses were measured using interferon-, Elispot assays after stimulation with overlapping peptide pools spanning the complete HCV genome. CD4+ memory- T-cell responses were determined after 12-day stimulation with HCV proteins. The maximum response was compared between individuals. The T-cell responses measured directly ex vivo were weak but significantly higher in resolvers compared to chronic carriers, whereas the CD4+ memory -T-cell response was not different between resolvers and chronic carriers. However, HCV Core protein was targeted more often in chronic carriers compared to individuals resolving HCV infection. CD4+ T-cell responses predominantly targeting nonstructural proteins were associated with resolved HCV infection. Interestingly, observation of memory-T-cell responses present before the documented HCV-seroconversion suggests that reinfections in IDUs occur often. The presence of these responses however, were not predictive for the outcome of infection. However, a transition of the HCV-specific CD4+ memory -T-cell response from targeting Core to targeting nonstructural proteins during onset of infection was associated with a favourable outcome. Therefore, the specificity of the CD4+ memory -T-cell responses measured after 12-day expansion seems most predictive of resolved infection. [source] A longitudinal analysis of cytotoxic T lymphocyte precursor frequencies to the hepatitis B virus in chronically infected patientsJOURNAL OF VIRAL HEPATITIS, Issue 1 2001G. K. Sing Individuals with acute hepatitis B virus (HBV) infection characteristically mount a strong, multispecific cytotoxic T lymphocyte (CTL) response that is effective in eradicating virus. In contrast, this response in chronic carriers is usually weak or undetectable. Since it is generally acknowledged that HBV pathogenesis is immune-mediated, the occurrence of episodes of active liver disease in many carriers suggests that these individuals can mount active CTL responses to HBV. To see whether the detection of circulating CTLs is related to these flare episodes, we have determined the CTL precursor (CTLp) frequencies to HLA-A2-restricted viral peptides in seven patients over a 12,24-month period of their disease. Limiting dilution analyses (LDA) were performed longitudinally to five epitopes comprising the viral capsid (HBc), envelope (HBs) and polymerase (pol) proteins. Assays were performed against a mixture of peptides, or against each individual peptide, to measure overall CTL activity and the multispecificity of the responses, respectively. Since two of the patients were treated with recombinant human interleukin-12 (rHuIL-12) at the time, with one individual achieving complete disease remission a year later after being treated with interferon-,, we were also able to examine the effects of these cytokines on HBV cytotoxicity. Our results indicate that weak but detectable CTL responses do occur in chronic carriers which are generally associated with disease flares, although CTLps were also seen occasionally during minimal disease activity. The range of specificities varied between individuals and within each individual during the course of the disease. Finally, we also provide evidence that CTL reactivity is stimulated following treatment with certain cytokines, but is dependent on the time of administration. [source] A virological perspective on the need for vaccinationJOURNAL OF VIRAL HEPATITIS, Issue 2000S. Locarnini Superinfecton of chronic carriers of hepatitis B virus (HBV) or hepatitis C virus (HCV) with hepatitis A virus (HAV) is often associated with more severe liver disease than infection with HAV alone. Superinfection commonly causes markers of HBV and HCV replication to fall to significantly lower levels. The pathogenesis of acute liver damage characteristic of viral hepatitis is thought to be mediated by host cytotoxic T-lymphocytes (CTLs) directed against virus-infected hepatocytes. It has been proposed that the more aggressive liver disease observed in individuals infected with HAV in addition to chronic HBV/HCV is a result of the induction of interferon (IFN)-, during acute HAV infection. This accounts for the antiviral effect on the active markers of HBV/HCV replication, and the enhanced CTL response against HBV/HCV-infected hepatocytes. Alternatively, HAV may indirectly stimulate the T helper 1 (Th1)-type cytokine responses, such as interleukin (IL)-2, IFN-, and tumour necrosis factor (TNF)-,, which directly promote the antiviral CTL response. Clearance of HBV infection, and possible HAV and HCV, is associated with a specific CTL response, while viral persistence in chronic HBV and HCV infection has been attributed to an imbalance in the Th1,Th2 arms of the immune response. Vaccination against hepatitis A should be considered for patients with chronic HBV/HCV infection, to minimize the risk of exacerbating underlying liver disease. [source] Lamivudine treatment in maternally transmitted chronic hepatitis B virus infection patientsPEDIATRICS INTERNATIONAL, Issue 4 2005Yen-Hsuan Ni Abstract, Background:,Lamivudine treatment in chronic carriers who acquired hepatitis B virus through maternal transmission were investigated. Methods:,A total of 29 subjects (Male : Female, 24:5; mean age, 14.7 ± 5.6 years) who were hepatitis B e antigen (HBeAg) seropositive for >6 months, alanine aminotransferase (ALT) was >1.3 times of upper limit of normal value, and receiving a 52 week-long treatment, received open-label lamivudine (3 mg/kg per day, maximum 100 mg/day). Another 29 subjects matched for gender, age, liver function, and HBeAg status followed up before the introduction of lamivudine served as the control group. The control group did not receive any treatment and were evaluated at week 52 after the onset of abnormal ALT. Mothers of all study subjects were hepatitis B surface antigen (HBsAg) carriers. A successful treatment response at week 52 was defined as: (i) undetectable hepatitis B virus DNA by real time polymerase chain reaction; (ii) normal ALT; and (iii) HBeAg/anti-HBe seroconversion. Lamivudine-resistant YMDD mutants were checked at week 52. Results:,The lamivudine group did not reach a better successful treatment response rate than the control group (17 vs 10%, P = 0.44), except in patients with a baseline ALT >5 times of the upper limit of normal value. YMDD mutants developed in 34% of patients in the lamivudine group. Conclusion:,Lamivudine treatment is effective for maternally transmitted subjects with high ALT. [source] Production of Hepatitis B Surface Antigen in Recombinant Plant Systems: An UpdateBIOTECHNOLOGY PROGRESS, Issue 3 2007G. B. Sunil Kumar There is a growing interest to develop oral vaccines for infectious diseases, as it is the most convenient and effective way to attain mucosal immunity. Hepatitis B continues to be a major infectious disease in many developing countries despite the availability of recombinant vaccine. On a global scenario, Hepatitis B Virus infection is probably the single most prevalent cause of persistent viraemia in humans. There are about 350 million chronic carriers of HBV, which is about 5% of the total world population. It is estimated that 75,100 million of them will die of liver cirrhosis and/or hepatocellular carcinoma. Progress in plant genetic engineering has enabled the transfer of useful genes for desirable traits. The recent trend is to use this technique to exploit plants as biofactories for the production of therapeutic proteins including vaccines. Rapid progress has been made in this area to develop plant-based vaccines for hepatitis B. This review describes the expression, characterization, and immunogenicity studies of hepatitis B vaccines produced in recombinant plant systems and their implications for developing a plant-based vaccine. [source] Development of an English as a second language curriculum for hepatitis B virus testing in Chinese Americans,CANCER, Issue S12 2005Gloria D. Coronado Ph.D. Abstract Chinese Americans are at disproportionately high risk of liver cancer. A major risk factor for liver cancer in Asia is infection with hepatitis B virus (HBV): Approximately 80% of liver cancers are linked to HBV, and chronic carriers of HBV are > 100 times more likely to develop liver cancer compared with noncarriers. However, many adults, particularly those who have immigrated to the U.S., remain untested and therefore unvaccinated or unmonitored for the disease. Chinese Americans are mostly foreign born, and more recent arrivals face multiple social and health challenges. Many require special attention from public health professionals because of low levels of acculturation and difficulties learning English. It has long been established that an English as a Second Language (ESL) curriculum can teach immigrant adults and their family's important life skills, such as job training and citizenship. The authors report on their plans to develop and pilot test a culturally appropriate curriculum that will motivate Chinese ESL students to obtain a blood test for the detection of the HBV. Cancer 2005. © 2005 American Cancer Society. [source] | |||||||||||||