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1.
J Viral Hepat ; 13(2): 96-103, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16436127

RESUMO

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. For each test (HBV DNA level at baseline, HBV DNA decrease between baseline and weeks 8 and 12, or the combination of these two, as well as HBeAg level at baseline, HBeAg decrease between baseline and weeks 8 and 12, and the combination of these two), we calculated the positive predictive value, negative predictive value, sensitivity and specificity. Monitoring with quantitative HBV DNA levels (area under ROC 0.87) was superior to monitoring with quantitative HBeAg levels (0.76, P < 0.05). Step-wise logistic regression identified HBV DNA at baseline and decrease in HBV DNA from baseline to week 12, as independent predictors of response. The overall test performance of predicting nonresponse (predictive value 100%) was best for log HBV DNA testing at week 12 compared with testing at week 8 due to a better prediction of sustained response (46%vs 38%) and lower misidentification of nonresponse (39%vs 54%). This study showed that quantitative HBV DNA testing at baseline in combination with a decrease between baseline and week 12 has a high predictive value for identifying patients who have virtually no chance of reaching a sustained response with IFN therapy.


Assuntos
Antivirais/uso terapêutico , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Adolescente , Adulto , Idoso , DNA Viral/sangue , Feminino , Marcadores Genéticos/genética , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Hepatite B Crônica/sangue , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Resultado do Tratamento , Carga Viral
2.
Vaccine ; 20(23-24): 2899-905, 2002 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-12126900

RESUMO

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<0.001). This vaccine dependent discrepancy was also observed with the Vidas anti-HBs assay (BioMerieux). An external WHO reference panel could harmonise geometric mean anti-HBs levels from the four assays for GenHevacB but not for Engerix-B vaccination sera. We conclude that the individually determined anti-HBs level (IU/l) strongly depend on the test reagents and the vaccine under study.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/farmacologia , Imunoensaio/métodos , Vacinas Sintéticas/farmacologia , Hepatite B/imunologia , Hepatite B/prevenção & controle , Humanos , Imunoensaio/normas , Imunoensaio/estatística & dados numéricos , Indicadores e Reagentes , Padrões de Referência , Sensibilidade e Especificidade , Organização Mundial da Saúde
3.
Vaccine ; 20(17-18): 2191-6, 2002 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-12009272

RESUMO

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. Hansenula-derived HBsAg was standardised on the basis of protein content at >95% purity. Standardisation was controlled by monoclonal anti-HBs binding in a well-conserved region. Sera were obtained after immunisation with type adw, ayw and adr vaccines. Direct binding of immune antibodies to homologous antigen (in EIA) was higher than to heterologous antigen except for the adr-related antibodies. Since the binding of the WHO reference anti-HBs was strongly reduced for the ayw and adr compared to the adw antigen, a similar binding profile for the three antigens on protein basis could result in 2-3-fold different anti-HBs level expressed in IU/l. Inhibition of Hansenula-derived HBsAg binding to solid phase monoclonal anti-HBs in enzyme immunoassays after incubation with serum anti-HBs confirmed the differential binding of serum anti-HBs with variant Hansenula-derived HBsAg. This variant (antigenic subtype) dependent reactivity of anti-HBs in immunoassays in combination with a variant specific WHO standard may limit the application of the threshold levels of 10 and 100 IU/l for seroconversion and seroprotection.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Vacinas Sintéticas/imunologia , Adulto , Vetores Genéticos , Anticorpos Anti-Hepatite B/imunologia , Humanos , Pichia , Proteínas Recombinantes de Fusão/imunologia , Vacinação
4.
J Viral Hepat ; 9(3): 221-8, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12010511

RESUMO

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. A benefit of anti-HBs in HBV patients has so far only been investigated in three small studies. In this pilot study we investigated the effects of polyclonal i.v. HBIg (HepatectR, Biotest) administration in HBV-infected patients. Six liver biopsy-proven HBV-infected patients, all on lamivudine treatment and HBV DNA negative by PCR, were investigated. Pre-treatment HBsAg levels varied between 120 and 9760 ng/mL. On day 1, 10.000 IU HBIg was given, followed by 10.000 IU once, twice or three times on day 29. Long-term follow-up lasted at least 4 months. HBsAg and anti-HBs were measured quantitatively by standard MEIA and also by an experimental EIA. In vitro neutralization of HBsAg by Hepatect was mimicked in an 'inhibition in solution assay'. Complete neutralization of HBsAg by HBIg in vitro was possible, 50% inhibition concentrations varied between 100 and 250 IU/L HBIg with HBsAg levels of 68 and 120 ng/mL. No HBIg-related side-effects were observed. In two patients with low pretreatment HBsAg levels HBsAg reached levels below the detection limit of the assay, which persisted a maximum of 31 and 7.5 h, respectively. Peak anti-HBs concentrations were 5100 and 4648 IU/L. In the other four patients, with higher pretreatment HBsAg levels, HBsAg concentrations in serum hardly changed. For the whole population, the drop in HBsAg did not reach statistical significance. However, in four of the six patients a further decrease in HBsAg [18%-66%] was observed. In conclusion, HBIg was well tolerated; however, efficacy was limited due to high HBsAg levels in spite of maximum inhibition of virion production. 'Neutralization' was achieved only in two patients with low HBsAg levels. Passive immunization in HBV-DNA negative patients is not a feasible option. This strategy seems only feasible if agents inhibiting both the production of viral proteins and Dane particles more selectively, become available.


Assuntos
Hepatite B Crônica/terapia , Imunização Passiva , Imunoglobulinas/administração & dosagem , Imunoglobulinas/uso terapêutico , Lamivudina/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Adulto , Terapia Combinada , DNA Viral/sangue , Feminino , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/isolamento & purificação , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização
5.
J Med Virol ; 66(3): 304-11, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11793381

RESUMO

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). 1Ff4 competes in part with a monoclonal antibody for the w/r region. Partial inhibition of binding of HBsAg/adw(2) to solid phase anti-HBs was detected, resembling inhibition obtained using other human monoclonal specific for the "a"-loop. 1Ff4 does not bind to linear peptides covering the two "a"-loops or to an adw(2)/G145R mutant, its binding to wild type HBsAg strongly depends on the presence of disulphide bonds. In a large series of HBsAg-positive samples from an endemic area, 1Ff4 antibodies were successfully used to discriminate between an adw(2) and an adrq+ strain. The characterisation of 1Ff4 and other human monoclonal anti-HBs antibodies may help to understand the fine specificity of protective antibodies elicited by immunization.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/imunologia , Hepatite B/prevenção & controle , Vacinas Sintéticas/imunologia , Ligação Competitiva , Epitopos de Linfócito B/imunologia , Humanos , Imunização , Imunização Secundária , Soluções
6.
J Med Virol ; 64(4): 427-34, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11468726

RESUMO

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. The results showed that (1) TUVIRUMAB was able partially to "neutralize" in vitro and in vivo, (2) HBsAg/TUVIRUMAB complexes can be traced by assays that capture the complex at either its HBsAg or its TUVIRUMAB component, (3) the final concentration of TUVIRUMAB at the end of therapy varied greatly but seemed to be related to HBsAg production at the start of therapy, (4) for at least 14 days after discontinuation of therapy, a minimal HBsAg level could be maintained in the presence of a declining TUVIRUMAB titer in patients with less than 3 microg/ml HBsAg before the start of therapy, (5) three months after therapy, all HBsAg levels had returned to pre-treatment levels and TUVIRUMAB had disappeared.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Complexo Antígeno-Anticorpo/sangue , Anticorpos Anti-Hepatite B/uso terapêutico , Hepatite B Crônica/terapia , Lamivudina/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Anticorpos Monoclonais/sangue , Estudos de Coortes , Relação Dose-Resposta a Droga , Anticorpos Anti-Hepatite B/análise , Antígenos de Superfície da Hepatite B/análise , Antígenos de Superfície da Hepatite B/imunologia , Hepatite B Crônica/sangue , Hepatite B Crônica/virologia , Humanos , Injeções Intravenosas , Testes de Neutralização
7.
Vaccine ; 19(27): 3671-80, 2001 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-11395201

RESUMO

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). Anti-HBs binding to synthetic peptids (25-mers, 7aa overlap) from the "a"-loop was significantly reduced by the G145R substitution and by changing the amino acid sequence from adw(2) into adr. With mutant G145R rHBsAg the inhibitory activity of vaccine anti-HBs was decreased compared to rHBsAg wild type. In general only minor differences were observed between plasma vaccine and recombinant DNA vaccine related antibody responses. However, the individual heterogeneity in epitope specific reactivity with its possible consequences for protection (against escape mutants) is not reflected in an anti-HBs titer by standard anti-HBs assays. The presented differentiation in anti-HBs response after immunization may deliver new tools for evaluation of future vaccines.


Assuntos
Sítios de Ligação de Anticorpos , Anticorpos Anti-Hepatite B/metabolismo , Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/metabolismo , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Mutação , Vacinas de DNA/imunologia , Sequência de Aminoácidos , Substituição de Aminoácidos/imunologia , Anticorpos Monoclonais/metabolismo , Ligação Competitiva/imunologia , Anticorpos Anti-Hepatite B/biossíntese , Humanos , Esquemas de Imunização , Vacinas de DNA/administração & dosagem
8.
J Med Virol ; 63(3): 217-9, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11170060

RESUMO

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. HBeAg was monitored by the AxSYM HBe 2.0 Quantitative (Abbott Laboratories) and HBV-DNA by liquid hybridisation (Abbott Laboratories). At the end of treatment (week 16) 24 patients had responded (HBeAg and HBV-DNA below the level of detection). Response was significantly (P = 0.007) related to a decrease in HBeAg level before the start of therapy. Eight of the 24 (33%) responding patients exhibited a > 50% decrease in HBeAg level just before the start of therapy compared to 7 of the 97 (7%) non-responding patients. The geometric mean titre of HBeAg decreased significantly (P < 0.005; 8-week period before start) among responding patients (271 ( 98 PEI U/ml) in contrast to non-responding patients (737 ( 724 PEI U/ml). Planning the start of interferon treatment just after a spontaneous decrease in HBV replication may increase the response rate for interferon-alpha therapy.


Assuntos
Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Replicação Viral , DNA Viral/sangue , Esquema de Medicação , Antígenos E da Hepatite B/sangue , Humanos , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Proteínas Recombinantes , Resultado do Tratamento
9.
J Viral Hepat ; 7(5): 382-6, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10971827

RESUMO

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. During the first 8 weeks of therapy, a decrease in HBeAg of less than 40%, as observed in 30% of the patients, consistently resulted in non-response. After 16 weeks of treatment, non-responding patients were randomly assigned to receive no further treatment (n=57) or prolonged treatment for another 16 weeks (n=61). In both groups, changes in the HBeAg level from the start of (the first) therapy to week 8, but not the pretreatment HBeAg level itself, were significantly related to the response at week 52 (the end of follow-up). Changes in the HBV DNA level had no additional predictive value for response at weeks 16 or 52. Therefore, instead of sequential HBV DNA assessment, we recommend monthly monitoring of HBeAg during IFN-alpha therapy.


Assuntos
Antivirais/uso terapêutico , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , DNA Viral/sangue , Vírus da Hepatite B/isolamento & purificação , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/virologia , Humanos , Interferon alfa-2 , Prognóstico , Proteínas Recombinantes , Resultado do Tratamento
11.
Vaccine ; 18(15): 1531-8, 2000 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-10618551

RESUMO

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. Antigens and/or antibodies were subjected to three types of experiments: (a) binding of 'a'-loop specific monoclonal (anti-S) antibody conjugates to immobilised vaccine-HBsAg; (b) binding of post-vaccination anti-HBs to immobilised (vaccine-)HBsAg and (c) inhibition of HBsAg binding to immobilised monoclonal anti-HBs after pre-incubation with post-vaccination antibodies. Our results show that, in both antigen presentation and anti-HBs binding properties, yeast recombinant HBsAg and related antibodies could be clearly distinguished from plasma-derived HBsAg and related antibodies. Divergent results were also obtained in the inhibition assay with recombinant DNA-derived HBsAg but not with serum HBsAg from the vaccine HBsAg subtype. It is concluded that both antigen presentation in vaccines and in anti-HBs assays can markedly influence the quantitation anti-HBs response. It is suggested that a challenge with an heterologous hepatitis B virus may encounter reduced efficacy of vaccine antibodies.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/imunologia , Vacinas de DNA/imunologia , Apresentação de Antígeno , Antígenos de Superfície da Hepatite B/imunologia , Humanos , Imunização
12.
J Gen Virol ; 80 ( Pt 8): 2121-2126, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10466811

RESUMO

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. Synthetic peptides (residues 175-189) including the 4-7B epitope sequence were able to evoke an anti-HBs response in rabbits. According to established polypeptide models, the 4-7B epitope region is located in the lipid layer of 20 nm HBsAg particles. The present results, however, suggest that residues 178-186 are exposed on the surface of the 20 nm particle. This may change our view of the structure of HBsAg.


Assuntos
Epitopos de Linfócito B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células COS , Mapeamento de Epitopos , Epitopos de Linfócito B/genética , Variação Genética , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Humanos , Camundongos , Dados de Sequência Molecular , Peptídeos/genética , Peptídeos/imunologia , Coelhos
13.
Hepatology ; 30(1): 238-43, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10385662

RESUMO

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 randomized to prolongation of the identical regimen up to 32 weeks (prolonged therapy) or discontinuation of treatment (standard therapy). Among the 162 patients who entered the study, 27 (17%) were HBeAg-negative after the first 16 weeks of treatment, and 118 were randomized to standard or prolonged therapy. After randomization, a response (HBeAg seroconversion and sustained hepatitis B virus [HBV]-DNA negativity) was observed in 7 of the 57 (12%) patients assigned to standard therapy versus 17 of the 61 (28%) patients assigned to prolonged therapy (P =.04). A low level of viral replication after 16 weeks of treatment, as indicated by serum HBV-DNA values under 10 pg/mL, was found to be the only independent predictor of response (52% vs. 0%; P <.001) during prolonged therapy. The prolonged IFN-alpha schedule was well tolerated in the large majority of patients. In chronic hepatitis B, prolongation of IFN-alpha therapy up to 32 weeks is superior to a standard course of 16 weeks. Those patients who exhibit a low level of viral replication at the end of the standard regimen benefit most from prolonged treatment.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/terapia , Interferon-alfa/uso terapêutico , Adolescente , Adulto , Idoso , Antivirais/efeitos adversos , DNA Viral/sangue , Esquema de Medicação , Europa (Continente) , Feminino , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/isolamento & purificação , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/sangue , Humanos , Interferon alfa-2 , Interferon-alfa/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Proteínas Recombinantes , Fatores de Tempo , Replicação Viral/efeitos dos fármacos
14.
J Med Virol ; 57(4): 331-6, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10089042

RESUMO

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. The virus genotype was D, antigenic subtype ayw2. Base sequence analysis of S- and C-gene regions revealed no differences between the two groups. During the acute illness the three patients who developed chronicity had a remarkable transient reduction of HBsAg, HBeAg, and HBV DNA levels at 14-20 weeks after infection, the time of HBeAg seroconversion in the patients who cleared the infection. One HBeAg-specific monoclonal antibody (HBOT.95A) used as solid-phase antibody in a sandwich enzyme immunoassay detected an increased HBeAg signal in 2 of the 3 patients that developed chronicity and in 1 of the 12 patients who recovered. The latter patient had an exceptional long period of HBsAg antigenemia. Standard HBeAg assays detected HBeAg in all cases. HBeAg and anti-HBe-positive serum samples from the patients who recovered could inhibit the HBOT.95A response. The results suggest that chronic hepatitis B develops after an interruption of immune clearance. Differentiation of the antibody response to HBeAg may help to find patients with an increased risk for this interrupted immune clearance who might be candidates for an early intervention therapy.


Assuntos
Hepatite B Crônica/fisiopatologia , Hepatite B/fisiopatologia , Doença Aguda , Anticorpos Monoclonais , DNA Viral/análise , Surtos de Doenças , Feminino , Fertilização in vitro/efeitos adversos , Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Antígenos E da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Humanos , Técnicas Imunoenzimáticas , Gravidez , Complicações Infecciosas na Gravidez/virologia , Prognóstico
15.
J Hepatol ; 28(6): 951-9, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9672169

RESUMO

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. RESULTS: Three hundred and thirty-six patients received treatment. The sustained response rate for patients receiving 3 MU tiw for 6 months was 14% (9-21%,) and for patients receiving double dose tiw for 8 weeks and thereafter titrated therapy 15% (10-21%) (p=0.8). Pretreatment factors associated with a sustained alanine aminotransferase plus HCV RNA response were the absence of cirrhosis, presence of genotype 2 or 3, a low viral load and, in addition, a low alanine aminotransferase/aspartate aminotransferase ratio; a model was developed to allow estimation of the chance of response for the individual patient. The most powerful predictor of sustained response, however, was plasma HCV RNA at week 4; a positive test virtually precluded a sustained response (1.7%, 0.4-5.0%). If week 4 HCV RNA was not detectable, the chance of a sustained response was 21% (12-34%) for genotype 1 versus 40% (28-54%) for the others (p=0.02). Six MU tiw led to a significantly higher week 4 HCV RNA response (47% not detectable) than 3 MU (37%) (p=0.02). During down-titration this difference in viral on-treatment response was lost. CONCLUSIONS: In the treatment of hepatitis C, an early HCV RNA response is a prerequisite for long-term efficacy. Doubling the initial interferon dose increases this early response, but subsequent downward titration negates this effect, especially in genotype 1.


Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/terapia , Interferon-alfa/uso terapêutico , Adulto , Idoso , Alanina Transaminase/sangue , Antivirais/administração & dosagem , Aspartato Aminotransferases/sangue , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Seguimentos , Genótipo , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C Crônica/sangue , Hepatite C Crônica/patologia , Humanos , Injeções Subcutâneas , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Probabilidade , RNA Viral/sangue , Proteínas Recombinantes , Fatores de Tempo
16.
Liver ; 18(1): 32-8, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9548265

RESUMO

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%). Patients originating from Surinam (South America) had predominantly type 2 (9/10, 90%), whereas Africans were mainly infected with type 4 (7/9, 77%). Blood transfusion was the mode of transmission in 142 (50%) patients, intravenous drug abuse (IVDA) in 40 (14%), occupational needle accident or tattoo in 11 (4%); no obvious source of infection was found in 93 (33%). In patients infected by blood transfusion, subtype 1b was predominant (70%, CI 61-77%), whereas subtypes la and 3 were predominant in those infected by IVDA (25% and 45%, respectively, p<0.001). Cirrhosis was observed in 68 (24%) patients; in multivariate analysis, factors independently related to cirrhosis were: the duration of infection, age and prior hepatitis B. No significant relationship was found between the severity of fibrosis or liver inflammation and the HCV (sub)types. In summary, in this large cohort of patients in the Benelux countries the hepatitis C virus (sub)type present was clearly related to the country of origin and the route of transmission, but not to the severity of liver disease.


Assuntos
Hepacivirus/genética , Hepatite C Crônica/epidemiologia , Adulto , África/epidemiologia , Idoso , Alanina Transaminase/sangue , Ásia/epidemiologia , Estudos de Coortes , Europa (Continente)/epidemiologia , Feminino , Genes Virais/genética , Genótipo , Hepatite C Crônica/genética , Hepatite C Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , RNA Viral/análise , América do Sul/epidemiologia
17.
Vaccine ; 15(15): 1624-30, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9364693

RESUMO

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. Eight infants (1.1%), all born to HBeAg-positive mothers, became HBsAg carriers within the first year of life. The protective efficacy rate (PER) of passive-active immunization at 12 months follow-up was 92% for the total group of children from 114 HBeAg-positive mothers with no significant differences between children starting active immunization at birth or at 3 months of age, between infants starting at 3 months of age receiving one or two doses of HBIg or between those receiving plasma derived or recombinant vaccine. The only factor that affected the PER significantly was the level of maternal HBV DNA; PER was 100% if maternal HBV DNA was < 150 pg ml-1 and 68% for HBV DNA levels > 150 pg ml-1. After 5 years of follow-up, the group that started active immunization at birth had significantly more infants with loss of seroprotection (anti-HBs levels < 10 IU l-1, 15%) than the corresponding group starting at 3 months of age (anti-HBs < 10 IU l-2, 2%). One of 35 children with loss of seroprotection at 2 years became a HBsAg carrier in the fifth year of follow-up. This meta-analysis shows that the protective efficacy of passive-active hepatitis B vaccination is mainly influenced by material HBV DNA levels, and independent of the time of starting active vaccination at birth or at 3 months of age; long-term immunity was enhanced by starting active vaccination concomitant with DKTP vaccination. These findings allow incorporation of hepatitis B vaccine into the standard infant immunization programs for countries with a passive-active immunization strategy for the control of hepatitis B. Additional measures are needed to protect neonates of highly viremic women.


Assuntos
Vacinas contra Hepatite B/imunologia , Hepatite B/prevenção & controle , DNA Viral/análise , Feminino , Seguimentos , Anticorpos Anti-Hepatite B/sangue , Humanos , Lactente , Recém-Nascido , Países Baixos , Gravidez , Fatores de Tempo , Vacinação
18.
J Med Virol ; 53(3): 282-7, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9365897

RESUMO

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 2.0 Quantitative, Abbott Laboratories) was undertaken in serial serum samples from 30 patients with 16-week interferon-alpha (IFN-alpha) treatment (follow-up 36 weeks; 14 responders) and from 15 patients with 24-week lamivudine treatment (follow-up 24 weeks; 2 responders). In the group of interferon-treated patients, the median pretreatment HBV-DNA level was significantly lower in responders compared to nonresponders (P = 0.02); the difference in median HBeAg level was not significant. However, the percentage of response was significantly related (P = 0.003) to the magnitude of decline in HBeAg level between the start of therapy and week 4. This phenomenon was not observed for HBV-DNA. Using multivariate analysis, it was found that the fall of HBeAg levels between weeks 0 and 4 was the most important independent predictor of response. In the group of lamivudine treated patients, the rapid decline in HBV-DNA (> 90%) in 12 patients at week 4 had no relation to HBeAg seroconversion. In contrast, the fall in HBeAg-level (one patient with > 50% reduction at week 4 seroconverted) appears to be predictive. Quantitation of HBeAg at start and early during therapy may have clinically important predictive value for long-term response to antiviral therapy.


Assuntos
Antivirais/uso terapêutico , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/imunologia , Interferons/uso terapêutico , Lamivudina/uso terapêutico , DNA Viral , Antígenos E da Hepatite B/genética , Vírus da Hepatite B , Humanos , Técnicas Imunoenzimáticas , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Ned Tijdschr Geneeskd ; 141(35): 1694-7, 1997 Aug 30.
Artigo em Holandês | MEDLINE | ID: mdl-9543786

RESUMO

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. METHOD: Twenty-six older residents (group P) with isolated anti-HBc positivity (HBsAg negative and anti-HBs < 10 IU/l) were given hepatitis B vaccine (3 doses); 16 matched controls (group C1) lacking hepatitis B markers, received a primary vaccination (3 doses), 8 controls (group C2) with a immune status based on infection in the past received vaccination (3 doses) and 27 controls (group C3) were given a booster vaccination (1 dose) after vaccination 7 years earlier. The anti-HBs response was measured 0, 1 and 7 months after the first vaccine dose. An anamnestic response was defined as a fourfold rise of anti-HBs after one dose of vaccine or--in the absence of an anti-HBs titer in the prevaccination serum--a response > or = 10 IU/l after one dose of vaccine. A primary response was defined as an anti-HBs response > or = 10 IU/l after giving 3 vaccines, while the criteria for an anamnestic response were not met. RESULTS: In the isolated anti-HBc group (P) and in the corresponding control group (C2) 15 and 12.5%, respectively, showed an anamnestic response; the majority reacted with a primary response or did not respond at all. The subjects given a primary vaccination (C1) responded in 62.5% with a primary response while those vaccinated earlier (C3) responded in 92.6% with a fourfold rise of anti-HBs. CONCLUSIONS: The anti-HBs response to vaccination in older mentally handicapped persons is delayed and there is a reduced chance of development of a protective anti-HBs titer. The majority of individuals with isolated anti-HBc showed a primary response. In these persons vaccination should not be omitted, especially if there is a risk of hepatitis B.


Assuntos
Demência/imunologia , Vacinas contra Hepatite B , Hepatite B/prevenção & controle , Idoso , Feminino , Hepatite B/imunologia , Antígenos do Núcleo do Vírus da Hepatite B/isolamento & purificação , Vacinas contra Hepatite B/imunologia , Humanos , Masculino , Estudos Prospectivos
20.
J Hepatol ; 23(6): 662-7, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8750164

RESUMO

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. Thirty patients with a median age of 34 years (range 21-52) were included. RESULTS: During an average follow up of 4.8 years, nine patients died. The overall 5-year survival as estimated by Kaplan-Meyer analysis was 71%, which was comparable to hepatitis B cirrhosis patients. However, in the group without active hepatitis B replication (HBeAg-negative) a clear trend towards a worse survival was identified in Delta cirrhosis patients. Complications and deaths occurred exclusively in the patient group with cirrhotic liver disease. The complications (ascites, elevated bilirubin >34 micro mol/l), variceal bleeding and spontaneous bacterial peritonitis) occurred in 52% of the patients with a follow up of more than 6 months (n=27). Fifty-seven percent of those patients died. In our population anti-Delta positive liver disease affects predominantly young patients and is related to advanced liver disease. CONCLUSIONS: In view of the high death rate, liver transplantation should be considered when signs or symptoms of decompensated liver disease occur.


Assuntos
Hepatite D/mortalidade , Adulto , Anticorpos Antivirais/sangue , Sequência de Bases , Feminino , Hepatite D/complicações , Hepatite D/patologia , Vírus Delta da Hepatite/genética , Vírus Delta da Hepatite/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Viral/análise , Taxa de Sobrevida
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