Search results for "aDNA"
showing 10 items of 65 documents
Regulation of the neutralizing anti-hepatitis B surface (HBs) antibody response in vitro in HBs vaccine recipients and patients with acute or chronic…
1996
Abstract Antibodies directed to the HBs antigen indicate viral clearance and the development of life-long immunity in patients that recovered from HBV infection. In HBs antigen vaccine recipients anti-HBs antibodies provide protective immunity. However, little is known about the regulation of this HBs-specific antibody response. The existence of anti-HBs-secreting B cells was demonstrated using the highly sensitive ELISPOT technique compared with conventional ELISA in serum and cell culture supernatants. In the peripheral blood of patients with acute self-limited hepatitis B, HBs-specific B cells were demonstrated with a high frequency despite undetectable anti-HBs serum antibodies. HBV-imm…
Can the serological status of anti-HBc alone be considered a sentinel marker for detection of occult HBV infection?
2008
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 amplifica…
Differential genetic determination of immune responsiveness to hepatitis B surface antigen and to hepatitis A virus: a vaccination study in twins.
2002
Summary Background The course of viral hepatitis is thought to be affected by genetic host variability and, in particular, by genes of the major histocompatibility locus. Hepatitis A and B vaccination is a useful model to study the effect of host factors on the immune response to viral antigens. We aimed to assess the heritability of the HBsAg (anti-HBs) and anti-hepatitis A virus (anti-HAV) immune response and to estimate the effect of the HLA-DRB1 locus and other genetic loci unlinked to HLA. Methods We did an open prospective study and vaccinated 202 twin pairs with a combined recombinant HBsAg/inactivated hepatitis A vaccine. We measured antibodies to HBsAg and HAV and determined HLA-DR…
Hepatitis B defective virus with rearrangements in the preS gene during chronic HBV infection.
1991
We have found a defective form of HBV2 in a HBsAg- and anti-HBe-positive patient with liver cancer. Viral deletions were identified in the preS coding region using PCR. The presence of deleted HBV forms was observed in serum, PBMC, and liver samples. After sequencing 12 clones were analyzed (subtype adr). In 9 out of 12 clones a 183-bp in-frame deletion was recorded in the preS1 region (2995 to 3177). Three out of 9 clones also yielded rearrangements of the preS2 N-terminal part. Four out of 9 showed numerous point mutations in the preS1 and preS2 sequence. In addition, 3 out of 12 clones, which did not show the 183-bp preS1 deletion were found to have small deletions and insertions in the …
Lack of hepatitis B virus DNA sequences in sera from patients with acute and chronic liver diseases diagnosed as non-A, non-B-hepatitis
2008
— The sera of 15 individuals with transfusion-associated acute or chronic non A, non B hepatitis, which lacked hepatitis B virus markers, were tested for hepatitis B virus DNA by dot blot hybridization test. Three sera of two patients positive in this test, however, also gave positive results when the labeled plasmid was used as probe instead of labeled HBV-DNA, indicating false positive results in the initial test. In conclusion, the data indicated that sera of patients with confirmed non A, non B hepatitis do not contain DNA-sequences in the serum hybridizing with HBV-DNA.
Correlation of hepatitis B virus, hepatitis D virus and human immunodeficiency virus type I infection markers in hepatitis B surface antigen positive…
1992
The hepatitis D virus (HDV) infection plays a major role in severe liver damage caused by hepatitis. To establish the prevalence of HDV infection in haemophilic patients and patients without haemophilia, 87 patients with chronic hepatitis B virus (HBV) infection were examined for serological evidence of delta hepatitis. In addition HBV, HDV and human immunodeficiency virus type 1 (HIV) infection markers were compared to clinical and histopathological outcome of hepatitis. Out of 46 haemophiliacs 30 (65%) were anti-HD-seropositive; 10 out of 30 anti-HD-positive patients (33%) had pathological liver function tests compared to 2 out of 16 anti-HD-negative haemophiliacs (13%). The rate of HIV i…
Virological profiles in patients with chronic hepatitis C and overt or occult HBV infection
2002
Abstract OBJECTIVES: The virological profiles of hepatitis B and C viruses (HBV and HCV) and their interplay in cases of coinfection are undefined. A suppressed and occult HBV infection may occur in hepatitis B surface antigen (HBsAg) negative patients with chronic hepatitis C. The HCV core protein is able to inhibit HBV “in vitro,” and serines at positions 99 and 116 are essential for such inhibition. We aimed to assess the HBV and HCV virological profiles in cases of coinfection and to evaluate the relationship between HCV core gene variability and HBV activity. METHODS: Eighty-two anti-HCV positive patients were examined: 35 cases were HBsAg positive, 24 were HBsAg negative with “occult”…
Occult hepatitis B virus in liver tissue of individuals without hepatic disease
2008
Abstract BACKGROUND/AIMS: While many data are available concerning occult hepatitis B virus (HBV) infection in patients with hepatic disorders, there is little information about this cryptic infection in individuals without liver disease. The aim of this study was to investigate the prevalence of occult HBV in the general population by examining liver specimens from a large series of HBV-surface-antigen negative individuals with no clinical and biochemical evidence of liver disease. METHODS: The presence of HBV DNA was evaluated by testing, through polymerase chain reaction techniques, DNA extracts from 98 liver-disease-free individuals who underwent liver resection or needle biopsy during …
Clinical evaluation and applications of the Amplicor HBV Monitor™ test, a quantitative HBV DNA PCR assay
1998
Viral load has emerged recently as a reliable marker of disease progression and therapeutic efficacy in chronic infections, including AIDS and hepatitis C. The clinical management of type B hepatitis could also be improved by monitoring viremia levels in patients with chronic liver disease undergoing anti-viral treatment. To address this question we evaluated the performance of a newly developed, quantitative PCR assay (Amplicor HBV Monitor test, Roche Diagnostic Systems) in the assessment of viremia changes over time in a group of 45 patients with chronic active hepatitis (CAH) who received interferon treatment. Of the 45 patients, 14 were HBsAg and anti-HBeAg positive and 31 HBsAg, HBeAg …
Peripheral blood dendritic cells are phenotypically and functionally intact in chronic hepatitis B virus (HBV) infection
2007
Summary Persistence of hepatitis B virus (HBV) infection is associated with reduced anti-viral T cell responses. Impaired dendritic cell (DC) function was suggested as the cause of reduced T cell stimulation in chronic HBV carriers. Thus, we compared myeloid (mDC) and plasmacytoid DC (pDC) from chronic HBV carriers and controls. Frequency and phenotype of isolated DC were analysed by fluorescence activated cell sorter staining, DC function by mixed lymphocyte reaction, cytokine bead array, intracellular cytokine staining, enzyme-linked immunosorbent assay and enzyme-linked immunospot. Expression of HBV DNA and mRNA was studied by polymerase chain reaction (PCR). Circulating total DC, mDC or…