Search results for "HB"

HBV recurrence after HCV clearance on DAAs: Sometimes they come back

2017

Priming of cytotoxic T cell responses to exogenous hepatitis B virus core antigen is B cell dependent

2003

The hepatitis B virus (HBV) core antigen (HBcAg) has a unique ability to bind a high frequency of naive human and murine B cells. The role of HBcAg-binding naive B cells in the immunogenicity of HBcAg is not clear. The HBcAg-binding properties of naive B cells were characterized using HBcAg particles with mutated spike region (residues 76-85) sequences. Deletion of residues 76-85 (HBcDelta76-85) destroyed naive B cell binding, whereas deletion of residues 79-85 did not. HBcAg particles with an Ile instead of the natural Ala at position 80 did not bind naive B cells, whereas reversion of Ile80--Ala restored B cell binding. Destroying the B cell-binding ability of HBcAg had a marginal effect …

Semiquantitative assessment of pre-core stop-codon mutant and wildtype hepatitis B virus during the course of chronic hepatitis B using a new PCR-bas…

1996

In most patients with chronic hepatitis B positive for antibodies (anti-HBe) to HBe antigen (HBeAg), a pre-core mutant hepatitis B virus (HBV) with a point-mutation at nt. 1896 can be isolated. Clinical significance of the mutant virus in chronic hepatitis B is not proven yet, and screening of large numbers of sera during different clinical courses of numerous patients is necessary. We therefore aimed to develop a fast and reliable assay, that allows to discriminate wildtype from nt. 1896 G-->A mutant HBV and to determine the ratio of mutant and wildtype HBV in patients' sera. A mutation specific polymerase chain reaction (ms PCR) with new primers served to distinguish nt. 1896 G-->A mutant…

Functional incorporation of green fluorescent protein into hepatitis B virus envelope particles

2004

AbstractThe envelope of hepatitis B virus (HBV), containing the L, M, and S proteins, is essential for virus entry and maturation. For direct visualization of HBV, we determined whether envelope assembly could accommodate the green fluorescent protein (GFP). While the C-terminal addition of GFP to S trans-dominant negatively inhibited empty envelope particle secretion, the N-terminal GFP fusion to S (GFP.S) was co-integrated into the envelope, giving rise to fluorescent particles. Microscopy and topogenesis analyses demonstrated that the proper intracellular distribution and folding of GFP.S, required for particle export were rescued by interprotein interactions with wild-type S. Thereby, a…

Mammalian BiP controls posttranslational ER translocation of the hepatitis B virus large envelope protein.

2008

AbstractThe hepatitis B virus L protein forms a dual topology in the endoplasmic reticulum (ER) via a process involving cotranslational membrane integration and subsequent posttranslational translocation of its preS subdomain. Here, we show that preS posttranslocation depends on the action of the ER chaperone BiP. To modulate the in vivo BiP activity, we designed an approach based on overexpressing its positive and negative regulators, ER-localized DnaJ-domain containing protein 4 (ERdj4) and BiP-associated protein (BAP), respectively. The feasibility of this approach was confirmed by demonstrating that BAP, but not ERdj4, destabilizes the L/BiP complex. Overexpressing BAP or ERdj4 inhibits…

Adefovir for lamivudine resistant HBV: More than meets the eye

2007

– In patients with LAM resistance and high levels of HBV-DNA, especially if HBeAg positive, it may be difficult to obtain a strong virological suppression with ADV. – Restrictive criteria are needed to define virological response (HBV-DNA < 10 3 copies/ml or 200 IU/ml). – Early finding of non-response or of suboptimal response after 9–12 months of ADV therapy suggests a high risk of emergence of ADV-resistant strains and should prompt a change of treatment strategy. In patients with cirrhosis, due to the risk of liver failure, treatment changes should be considered even earlier, at 3–6 months.

The long-term course of chronic hepatitis B

1999

The aim of this study was to assess the long-term outcome in hepatitis B virus (HBV)-infected patients according to HBV, hepatitis C virus (HCV), and hepatitis D virus (HDV) replication, focusing on survival, liver failure, and hepatocellular carcinoma (HCC). A cohort of 302 hepatitis B surface antigen (HBsAg)-positive subjects (mean age, 34 +/- 15.3 years; male/female 214/88; 39 subjects under 14 years) with biopsy-proven chronic hepatitis (86 with cirrhosis) was prospectively assessed, with a median follow-up of 94 +/- 37.6 months. One hundred nine patients received interferon alfa (IFN). At baseline, 86 subjects (28.5%) were hepatitis B e antigen (HBeAg)-positive (wild-type HBV), 80 (26.…

Survival and prognostic factors in 366 patients with compensated cirrhosis type B: a multicenter study.

1994

A multicenter longitudinal study was performed to assess the survival of hepatitis B surface antigen positive compensated cirrhosis, primarily in relation to hepatitis B virus replication and hepatitis delta virus infection, and to construct a prognostic index based on entry characteristics. This cohort study involved nine university medical centers in Europe. Three hundred and sixty-six Caucasian HBsAg positive patients with cirrhosis who had never had clinical manifestations of hepatic decompensation were enrolled and followed for a mean period of 72 months (6 to 202 months). Inclusion criteria were biopsy-proven cirrhosis, information on serum hepatitis B e antigen and antibody to hepati…

Effectiveness of a screening program for HBV, HCV, and HIV infections in African migrants to Sicily

2021

BACKGROUND Migrants from Africa are vulnerable to viral infections during their journey. METHODS Migrants who arrived in western Sicily were offered early screening for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection. A questionnaire was administered to evaluate risk factors, and antiviral therapy was offered to subjects with active infection. A multiple regression analysis and adjusted odds ratio were obtained to evaluate risk factors. RESULTS Overall, 2,639 of 2,751 (95.9%) migrants who arrived between 2015 and 2017 accepted screening and 1,911 (72.4%) completed the questionnaire. HBsAg was positive in 257 (9.7%) migrants, 24 (0.9%) were …

Interferon alfa for chronic hepatitis B infection: Increased efficacy of prolonged treatment

1999

Interferon alfa (IFN-alpha) is the primary treatment for chronic hepatitis B. The standard duration of IFN-alpha therapy is considered 16 weeks; however, the optimal treatment length is still poorly defined. We evaluated the efficacy and acceptability of prolonged IFN-alpha treatment in patients with chronic hepatitis B. To investigate whether treatment prolongation could enhance the rate of hepatitis B e antigen (HBeAg) seroconversion, we conducted a prospective, controlled, multicenter trial in which all patients were treated with a standard regimen of 10 million units IFN-alpha 3 times per week over 16 weeks. Patients who were still HBeAg-positive after 16 weeks of therapy were randomize…