Genetic characteristics of hepatitis B virus genotypes as a factor for interferon-induced HBeAg clearance.

The factors determining the responsiveness of different hepatitis B virus (HBV) genotypes to interferon treatment are not fully understood. We investigated the relationship between HBV genetic characteristics and the outcome of short (16 weeks) or prolonged (32 weeks) treatment with standard interferon-alpha in a prospectively followed cohort of 103 patients across Europe with HBeAg positive chronic hepatitis B. INNO-LiPA assays and HBV DNA sequencing were used to determine HBV genotypes, mutations in the core promoter and precore/core regions.

Quantitative HBV DNA levels as an early predictor of nonresponse in chronic HBe-antigen positive hepatitis B patients treated with interferon-alpha.

To reduce unnecessary exposure to treatment, physicians must decide at an early stage whether continuation of treatment has a reasonable chance of success for the individual patient. The objectives of our study were to evaluate the previously described quantitative hepatitis B e antigen (HBeAg) measurements vs quantitative hepatitis B virus (HBV) DNA measurements for prediction of nonresponse and response in interferon (IFN)-alpha treated HBeAg positive chronic HBV patients. Serum HBV DNA and HBeAg levels were assessed at baseline and weeks 8 and 12.

Anti-HBs levels after hepatitis B immunisation depend on test reagents: routinely determined 10 and 100 IU/l seroprotection levels unreliable.

In a large series of post-vaccination samples we compared the result of three commercially available anti-HBs assays (AxSYM, Architect and Access) on the quantitation of anti-HBs after immunisation with Engerix-B (HBsAg/ad) and GenHevacB (HBsAg/ay) vaccine. Two of the assays (AxSYM, Architect: Abbott Laboratories) gave related but not identical results with HBsAg from different sources. The result of the third assay (Access, Beckman Coulter) was related to that of AxSYM and Architect only for GenHevacB anti-HBs but differed for Engerix-B anti-HBs (P<0.

Passive immunization of chronic hepatitis B patients on lamivudine therapy: a feasible issue?

In view of the limited efficacy of lamivudine monotherapy for chronic hepatitis B (HBV) infection, combination with other drugs seems logical. Intravenous neutralization of circulating HBsAg by specific hepatitis B immunoglobulin (HBIg) has been shown to protect hepatocytes against (re-)infection with HBV in the setting of liver transplantation and postexposure prophylaxis. Large controlled vaccination trials have revealed that HBV can be prevented by HBIg therapy in the majority of newborns after perinatal infection.

Hepatitis B surface antigen (HBsAg) derived from yeast cells (Hansenula polymorpha) used to establish an influence of antigenic subtype (adw2, adr, ayw3) in measuring the immune response after vaccination.

As a product of western world biotechnology the yeast (Saccharomyces cerevisiae) hepatitis B vaccine was introduced as antigenic subtype adw2. However, an HBsAg/adw2-vaccine may provide a good but not "optimal" immunologic response for infection with heterologous virus strains. The availability of the yeast Hansenula polymorpha HBsAg in three different antigenic forms (adw2, ayw3 and adr) enabled us to investigate the influence of variant amino acids in the binding of immune anti-HBs after vaccination.

Characterization of a human monoclonal antibody obtained after immunization with plasma vaccine and a booster with recombinant-DNA hepatitis B vaccine.

A human monoclonal antibody type IgG4, designated 1Ff4, was obtained by Epstein Barr virus transformation of peripheral blood lymphocytes from a hepatitis B vaccinee (HB-VAX: plasma-derived vaccine) after one boost of yeast recombinant DNA derived vaccine (Engerix-B). 1Ff4 binds preferentially to HBsAg/adw(2) and HBsAg/ayw(1). In binding experiments, it competes with antibodies induced by vaccination with HB-VAX-DNA (yeast recombinant) and HB-VAX (plasma-derived vaccine).

Administration of a human monoclonal antibody (TUVIRUMAB) to chronic hepatitis B patients pre-treated with lamivudine: monitoring of serum TUVIRUMAB in immune complexes.

A human monoclonal anti-hepatitis B antibody preparation (TUVIRUMAB) was administered 6 times over a 2-week period in a dose-escalating scheme to chronic hepatitis B patients pre-treated with lamivudine. The capacity of the TUVIRUMAB antibody to "neutralize" hepatitis B surface antigen in the circulation was investigated by means of experimental enzyme-immunoassays. Monoclonal antibody conjugates enabled the detection of HBsAg, TUVIRUMAB, and HBsAg/TUVIRUMAB complexes.

Anti-HBs after hepatitis B immunization with plasma-derived and recombinant DNA-derived vaccines: binding to mutant HBsAg.

The G145R mutant of the small S-protein is a major escape mutant of hepatitis B virus observed in natural infection, after immunization and HBIG therapy. In a previous study we found that plasma-derived and recombinant DNA-derived vaccine HBsAg reacted differently with monoclonal antibodies sensitive for the G145R change. In the present study we investigated the binding of polyclonal anti-HBs obtained after immunization with plasma vaccine and recombinant DNA vaccine to synthetic peptides (adw(2), adr) and rHBsAg (HepG2) (ayw(3); wild type and a 145R mutant).

Interferon-alpha therapy for chronic hepatitis B: early response related to pre-treatment changes in viral replication.

Chronic hepatitis B patients with low pre-treatment HBeAg (and HBV-DNA) levels are more likely to respond to interferon-alpha therapy. In retrospect, this low level of HBeAg may have been reached just before the start of therapy. Pre-treatment changes in HBeAg levels were studied in 121 patients undergoing interferon-alpha 2B therapy.

Interferon-alpha therapy in chronic hepatitis B: early monitoring of hepatitis B e antigen may help to decide whether to stop or to prolong therapy.

Hepatitis B e antigen (HBeAg) was quantified before, during and after interferon-alpha administration in a trial of 162 chronic hepatitis B patients treated for 16 or 32 weeks. In 139 of these patients we examined the prognostic value of the pretreatment level of HBeAg and the reduction in HBeAg level at weeks 4 and 8 for response at week 16. Multivariate analysis showed that the HBeAg pretreatment level is a highly significant predictor of response (judged as HBeAg and hepatitis B virus [HBV] DNA negativity), followed by a decrease in HBeAg from the start of therapy to week 8.

Anti-HBs characteristics after hepatitis B immunisation with plasma-derived and recombinant DNA-derived vaccines.

Hepatitis B surface antigen derived from chronic hepatitis B carriers has been replaced almost completely by recombinant DNA-derived HBsAg for use as hepatitis B vaccine. Similarly, recombinant DNA-derived HBsAg is replacing plasma-derived HBsAg in standard anti-HBs assays. We analysed the influence of a change from plasma-derived HBsAg to recombinant DNA-derived HBsAg on antigen presentation in immunoassays and the characteristics of the anti-HBs antibodies after immunisation.

Localization of a unique hepatitis B virus epitope sheds new light on the structure of hepatitis B virus surface antigen.

In a search for monoclonal antibodies (MAbs) that can bind hepatitis B virus surface antigen (HBsAg) with amino acid substitutions in the immune dominant 'a' region (escape mutants) we investigated the epitope recognition site of the human MAb 4-7B. Pepscan analysis and experiments with alanine substitution as well as substitutions known from nature pointed to residues 178-186 in the small S protein with the amino acid sequence PFVQWFVGL (key amino acids in bold) as the minimal epitope. Single amino acid substitutions at positions 122(R/K)(d/y), 134(Y/F), 145(G/R), 148(T/A) and 160(K/R)(w/r), representing 'a' region variants in recombinant HBsAg COS-I cells, did not influence binding of MAb 4-7B.

Interferon alfa for chronic hepatitis B infection: increased efficacy of prolonged treatment. The European Concerted Action on Viral Hepatitis (EUROHEP).

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.

In vivo activity of a mixture of two human monoclonal antibodies (anti-HBs) in a chronic hepatitis B virus carrier chimpanzee.

A 35-year-old female hepatitis B virus carrier chimpanzee was infused with one dose of a mixture of human monoclonal antibodies 9H9 and 4-7B (antibodies against hepatitis B virus surface antigen; HBsAg). Blood samples were taken before and up to 3 weeks after infusion. HBsAg and antibodies against HBsAg (anti-HBs) were quantified by radioimmunoassay and enzyme immunoassay.

Characteristics of the early phase of chronicity in acute hepatitis B infection.

The mechanism of development of chronicity after acute hepatitis B infection has not been elucidated fully. Following a single source outbreak of hepatitis B among 79 adult women, three patients (4%) became chronic carriers of hepatitis B virus (HBV). We compared features of the virus and antibody response of the latter three patients with those of 12 HBeAg-positive cases with resolving infection.

Efficacy of interferon dose and prediction of response in chronic hepatitis C: Benelux study in 336 patients.

Background/aims: In an attempt to improve the limited efficacy of treatment of chronic hepatitis C with interferon-alpha 3 MU tiw, we studied the effects of double-dose therapy followed by downward titration, and analyzed the pre- and pertreatment factors associated with response or non-response.

Methods: Three hundred and fifty-four consecutive patients in 19 centers were randomized to interferon-alpha 3 MU tiw for 6 months or 6 MU tiw for 8 weeks followed by down-titration (3,1 MU tiw) till alanine aminotransferase remained normal and plasma HCV RNA was repeatedly undetectable. The primary outcome measure was sustained alanine aminotransferase and HCV RNA response 6 months after treatment.

Hepatitis C virus genotypes: epidemiological and clinical associations. Benelux Study Group on Treatment of Chronic Hepatitis C.

In a cohort of 292 chronic hepatitis C patients living in the Benelux countries the relationship between viral genotype and geographical origin, route of transmission, clinical characteristics and severity of liver disease was analyzed. HCV-RNA isolates could be classified by the Line Probe Assay (LiPA) as 1a, 1b, 2, 3, 4 or 5 in 286 (98%) cases. Patients of European origin were predominantly infected with HCV subtype 1b (164/254, 65%, CI 58-70%), as were patients of Asian origin (7/13, 54%).

Serum HBeAg quantitation during antiviral therapy for chronic hepatitis B.

Hepatitis Be antigen (HBeAg) seroconversion is considered the principal short-term goal of antiviral therapy in chronic hepatitis B. To test whether the pre- and per-treatment HBeAg quantitation has a higher predictive value than that of hepatitis B virus DNA (HBV-DNA) quantitation for the outcome of antiviral therapy in chronic hepatitis B. A quantitative measurement of HBV-DNA and HBeAg (AxSYM HBe 2.

Ten-year neonatal hepatitis B vaccination program, The Netherlands, 1982-1992: protective efficacy and long-term immunogenicity.

From 1982 to 1989, 705 infants born to HBsAg-positive mothers entered the Dutch neonatal hepatitis B vaccination program and received passive-active hepatitis B immunization in three randomized controlled trials testing variations in time of starting active vaccination, dose and type of vaccine, and number of hepatitis B immunoglobulin (HBIg) injections. A meta-analysis of individual patient data of the three randomized trials was performed to determine which independent host and vaccination related factors influence protective efficacy and long-term immunogenicity, and to assess whether hepatitis B vaccination concomitant with standard DKTP vaccination provides optimal protection. Statistical methodology included multivariate logistic regression analysis.

[Vaccination against hepatitis B possibly indicated for elderly institutionalized mentally handicapped persons with isolated anti-HBc positivity of the prevaccination serum].

Objective: To determine whether vaccination against hepatitis B may be omitted in persons with isolated positive anti-HBc.

Design: Prospective study using control groups. SETTING'S: Heeren Loo-Lozenoord, Ermelo, the Netherlands.

Conversion of 2',3'-dideoxyadenosine (ddA) and 2',3'-didehydro-2',3'-dideoxyadenosine (d4A) to their corresponding aryloxyphosphoramidate derivatives markedly potentiates their activity against human immunodeficiency virus and hepatitis B virus.

2',3'-Dideoxyadenosine (ddA), 2',3'-didehydro-2',3'-dideoxyadenosine (d4A) and their lipophilic 5'-monophosphate triester (aryloxyphosphoramidate) prodrugs were evaluated for their anti-retrovirus and anti-hepatitis B virus activity in various cell culture models. The aryloxyphosphoramidate derivatives of ddA (Cf 1093) and d4A (Cf 1001) showed markedly superior (100-1000-fold) efficacies than the parent drugs against human immunodeficiency virus type 1 (HIV-1), HIV-2, simian immunodeficiency virus (SIV), Moloney murine sarcoma virus (MSV) and human hepatitis B virus (HBV) replication regardless of the cell type in which the virus replication was studied (i.e.

Anti-HIV and anti-HBV activity and resistance profile of 2',3'-dideoxy-3'-thiacytidine (3TC) and its arylphosphoramidate derivative CF 1109.

A novel membrane-soluble prodrug of the 5'-monophosphate derivative of 3TC containing a phenyl group and the methyl ester of L-alanine linked to the phosphorus through a phosphoramidate bond with the primary amino moiety (designated Cf 1109) was prepared. The 3TC prodrug proved less potent an inhibitor of HIV-1 and HIV-2 replication in CEM cell cultures than 3TC, but lost only 20-fold antiviral potency in 2'-deoxycytidine kinase-deficient CEM/dCK- cells compared with a more than 2,000-fold decrease of activity of 3TC. In contrast, 3TC and Cf 1109 proved equally highly effective in inhibiting HBV release in supernatants of HBV-transfected Hep G2 2.

Survival and complications in a cohort of patients with anti-delta positive liver disease presenting in a tertiary referral clinic.

Background/aims: Our aim was to evaluate the clinical outcome and survival of patients with anti-Delta positive liver disease in The Netherlands.

Methods: We evaluated those patients visiting our hospital between 1978 and 1993 with respect to clinical, virological and histological parameters. During the follow-up period the occurrence of complications of the liver disease and survival was determined.

Proposal for routine antenatal screening at 14 weeks for hepatitis B surface antigen. Dutch Study Group on Prevention of Neonatal Hepatitis.

Objective: To develop a low cost, high compliance screening programme for identification of carriers of hepatitis B surface antigen in the obstetric population of the Netherlands.

Design: A seven year open, descriptive study of screening for hepatitis B surface antigen as part of routine prenatal laboratory testing at 14 weeks of gestation. Compliance with programme evaluated by checking delivery records (hospitals) or registration of births in the 30 participating municipalities (rural area).