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1.
S Afr Med J ; 108(8b): 47-50, 2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-30182913

RESUMO

Chronic viral hepatitis types B and C may eventually lead to the development of hepatocellular carcinoma. Although hepatitis B is readily preventable by vaccination, there is growing evidence that antiviral therapy directed against hepatitis B may reduce the risk of liver cancer among those already infected. There is no vaccine against hepatitis C, but the evidence is now strong that antiviral therapy with sustained virological response (viral cure) reduces, but does not eliminate, the risk of hepatocellular carcinoma.


Assuntos
Antivirais/farmacologia , Carcinoma Hepatocelular/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Humanos , Resultado do Tratamento
2.
Aliment Pharmacol Ther ; 47(7): 1001-1011, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29377191

RESUMO

BACKGROUND: To better understand symptoms experienced by patients infected with chronic hepatitis C virus (HCV), valid and reliable patient-reported outcome (PRO) measures are needed. AIM: To assess the reliability and validity of 10 patient-reported outcomes measurement information system (PROMIS) measures and the Headache Impact Test-6 (HIT-6) in a large national sample of patients with HCV. METHODS: Pre-treatment data from 961 patients with HCV starting direct acting antiviral therapy at 11 U.S. liver centers were analyzed. Internal reliability was evaluated using Cronbach's alpha coefficient; frequency distributions were examined for floor and ceiling effects; structural validity was investigated via item-response-theory models; convergent validity was evaluated using correlations with theoretically-similar items from the HCV-PRO and memorial symptom assessment scale (MSAS); and known-groups validity was investigated by observing PRO differences by liver disease status and number of comorbidities. RESULTS: The HIT-6 and the majority of the PROMIS measures yielded excellent reliability (alphas ≥ 0.87). Ceiling effects were infrequent ( < 4%), while 30%-59% of patients reported no symptoms (floor effects). The data supported structural validity of the HIT-6 and most PROMIS measures. The PROMIS measures showed moderate to strong correlations with theoretically-similar items from the HCV-PRO and MSAS (0.39-0.77). Trends were observed between worse PRO scores and advanced cirrhosis and greater number of comorbidities, lending support for known-groups validity. CONCLUSIONS: The psychometric properties of the HIT-6 and PROMIS measures performed satisfactorily in this large cohort of patients with HCV starting direct acting antiviral therapy. Opportunities exist for further refinement of these PROs. Evaluation of performance over time and in under-represented subgroups is needed.


Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Medidas de Resultados Relatados pelo Paciente , Psicometria/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Comorbidade , Estudos Transversais , Feminino , Formulários como Assunto , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/psicologia , Humanos , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/epidemiologia , Cirrose Hepática/psicologia , Masculino , Pessoa de Meia-Idade , Manejo da Dor , Reprodutibilidade dos Testes , Estados Unidos/epidemiologia , Adulto Jovem
3.
J Viral Hepat ; 24(4): 320-329, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27917600

RESUMO

The aim of this study was to assess the validity of categorization of chronic hepatitis B viral infection into stages or phases based upon measures of disease activity and viral load, assuming these phenotypes will be useful for prognostication and determining the need for antiviral therapy. We assessed the phenotype of hepatitis B of 1,390 adult participants enrolled in the Hepatitis B Research Network Cohort Study, using a computer algorithm. Only 4% were immune tolerant, while 35% had chronic hepatitis B (18% e antigen positive and 17% e antigen negative) while 23% were inactive carriers. Strikingly, 38% of participants did not fit clearly into any one of these groups and were considered indeterminant. The largest subset of indeterminants had elevated serum aminotransferases with low levels of HBV DNA (less than 10,000 iu/mL). Subsequent determination of hepatitis B phenotype on the next available laboratory tests showed that 64% remained indeterminant. These findings call into question the validity of conventional staging of hepatitis B, in large part because of the substantial proportion of patients who do not fit readily into one of the usual stages or phases. Further studies are needed of the indeterminant category of chronic hepatitis B viral infection, including assessments of whether patients in this group are perhaps in transition to another phase or if they are a distinct phenotype with a need to assess liver disease severity and need for antiviral therapy. (ClinicalTrials.gov identifier NCT01263587).


Assuntos
Biomarcadores , Hepatite B Crônica/classificação , Hepatite B Crônica/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , DNA Viral/sangue , Feminino , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Transaminases/sangue , Carga Viral , Adulto Jovem
4.
Aliment Pharmacol Ther ; 45(1): 115-126, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27790729

RESUMO

BACKGROUND: Chronic hepatitis C virus therapy in patients with advanced liver disease remains a clinical challenge. HCV-TARGET collects data in patients treated at tertiary academic and community centres. AIM: To assess efficacy of all-oral HCV therapy in advanced liver disease. METHODS: Between December 2013 and October 2014, 240 patients with a MELD score of ≥10 initiated HCV treatment with an all-oral regimen. Data from the 220 patients who completed 12-week follow-up were analysed. RESULTS: Genotype 1 (GT1) patients had higher sustained virological response (SVR) when treated with sofosbuvir plus simeprevir ± ribavirin than with sofosbuvir plus ribavirin (66-74% vs. 54%); GT1b vs GT1a (84% vs. 64%). SVR for GT2 was 72% with sofosbuvir plus ribavirin, while GT3 patients had a substantially lower response (35%). A decrease in MELD score was not clearly related to SVR over the short course of follow-up although some had improvements in MELD score, serum bilirubin and albumin. A predictor of virological response was albumin level while negative predictors were elevated bilirubin level and GT1a. Most patients with GT1 were treated with approximately 12-week duration of sofosbuvir and simeprevir ± ribavirin therapy while GT2 and GT3 patients were treated with approximately 12 and 24 weeks of sofosbuvir plus ribavirin respectively. CONCLUSIONS: All-oral therapies are effective among patients with advanced liver disease with high levels of success in GT2 and GT1b, and may serve to reduce the severity of liver disease after SVR. Treatment for GT3 patients remains an unmet need. Clinical trial number: NCT01474811.


Assuntos
Antivirais/administração & dosagem , Bases de Dados Factuais , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/diagnóstico , Cirrose Hepática/tratamento farmacológico , Administração Oral , Adulto , Quimioterapia Combinada , Feminino , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/epidemiologia , Humanos , Internacionalidade , Cirrose Hepática/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Ribavirina/administração & dosagem , Simeprevir/administração & dosagem , Sofosbuvir/administração & dosagem
5.
J Viral Hepat ; 23(8): 614-22, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26957110

RESUMO

GS-9857, an inhibitor of the hepatitis C virus (HCV) nonstructural protein (NS) 3/4A, demonstrates potent activity against HCV genotypes 1-6 and improved coverage against commonly encountered NS3 resistance-associated variants (RAVs). In this study, the safety, tolerability, antiviral activity and pharmacokinetics (PK) of GS-9857 were evaluated in patients with chronic HCV genotype 1-4 infection. Patients with genotype 1-4 infection received placebo or once-daily GS-9857 at doses ranging from 50 to 300 mg for 3 days under fasting conditions. GS-9857 was well tolerated; all reported adverse events (AEs) were mild or moderate in severity. Diarrhoea and headache were the most commonly reported AEs. Grade 3 or 4 laboratory abnormalities were observed in 17% of patients receiving GS-9857; there were no Grade 3 or 4 abnormalities in alanine aminotransferase, aspartate aminotransferase or alkaline phosphatase levels. GS-9857 demonstrated potent antiviral activity in patients with chronic HCV infection, achieving mean and median maximum reductions in HCV RNA of ≥3 log10 IU/mL following administration of a 100-mg dose in patients with HCV genotype 1a, 1b, 2, 3 or 4 infection. The antiviral activity of GS-9857 was unaffected by the presence of pretreatment NS3 RAVs. In patients with genotype 1-4 infection, GS-9857 exhibited linear PK and was associated with a median half-life of 29-42 h, supporting once-daily dosing. Thus, the tolerability, efficacy and pharmacokinetic profile of GS-9857 support its further evaluation for treatment of patients with chronic HCV infection.


Assuntos
Antivirais/administração & dosagem , Genótipo , Hepacivirus/classificação , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Compostos Macrocíclicos/administração & dosagem , Sulfonamidas/administração & dosagem , Adolescente , Adulto , Idoso , Ácidos Aminoisobutíricos , Antivirais/efeitos adversos , Antivirais/farmacocinética , Antivirais/farmacologia , Ciclopropanos , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Hepacivirus/isolamento & purificação , Humanos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Compostos Macrocíclicos/efeitos adversos , Compostos Macrocíclicos/farmacocinética , Compostos Macrocíclicos/farmacologia , Masculino , Pessoa de Meia-Idade , Placebos/administração & dosagem , Prolina/análogos & derivados , Quinoxalinas , Sulfonamidas/efeitos adversos , Sulfonamidas/farmacocinética , Sulfonamidas/farmacologia , Resultado do Tratamento , Carga Viral , Adulto Jovem
6.
Dig Dis Sci ; 61(6): 1728-34, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26781427

RESUMO

BACKGROUND: Overt hepatic encephalopathy (OHE) is a frequent complication of decompensated cirrhosis. AIMS: A multicenter prospective observational study was performed to assess the most commonly recorded presenting manifestations of OHE and its associated health-care burden. METHODS: Qualifying patients must have experienced ≥1 OHE episode within 30 days of enrollment (qualifying OHE) and were followed for recurrence (on-study OHE). RESULTS: Two hundred and sixty-five patients were enrolled at 30 sites and followed for up to 9 months (mean 72 days). Seventy-two patients experienced 122 on-study episodes; with 72, 23, and 13 having ≥1, ≥2, or ≥3 on-study episodes with median days to occurrence of the 1st, 2nd, and 3rd episode of 34, 19, and 11, respectively. The most frequently recorded OHE manifestations included confusion (78 %), change in mental status (57 %), disorientation (48 %), lethargy (46 %), and asterixis (45 %). West Haven grade was used inconsistently and recorded for only 28 % of episodes. Most qualifying and on-study episodes occurred on rifaximin (60 and 82 %, respectively) and were associated with hospitalization (68 and 85 %, respectively). Twenty-three patients experienced ≥2 on-study episodes within 2 months of enrollment on average (median 45 days) and accounted for 60 % of on-study episodes. CONCLUSIONS: In this prospective study, OHE's most commonly recorded presenting manifestations included confusion, altered mental status, disorientation, lethargy, and asterixis. As reflected by frequent recurrence and hospitalizations, OHE, particularly the approximately 10 % of "high-resource-utilizing" patients with frequent recurrence, continues to pose a major unmet medical need and health-care burden despite the use of rifaximin.


Assuntos
Encefalopatia Hepática/patologia , Cirrose Hepática/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Rifamicinas/administração & dosagem , Rifamicinas/farmacologia , Rifaximina , Adulto Jovem
7.
Aliment Pharmacol Ther ; 41(7): 671-85, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25627020

RESUMO

BACKGROUND: HCV-TARGET is a longitudinal observational study of chronic hepatitis C virus (HCV) patients treated with direct-acting anti-viral agents (DAAs) in a US consortium of 90 academic and community medical centres. AIM: To assess utilisation of response-guided therapy (RGT) and sustained virological response (SVR) of a large cohort of patients. METHODS: Patients received peginterferon (PEG-IFN), ribavirin and either telaprevir or boceprevir. Demographical, clinical and virological data were collected during treatment and follow-up. RGT and treatment futility stopping rules was assessed at key time points. RESULTS: Of 2084 patients, 38% had cirrhosis and 56% had received prior treatment for HCV. SVR rates were 31% (95% CI: 24-40) and 50% (95% CI: 44-56) in boceprevir patients with and without cirrhosis, respectively. SVR rates were 46% (95% CI: 42-50) and 60% (95% CI: 57-64) in telaprevir patients with and without cirrhosis, respectively. Early clearance of virus, IL28B genotype, platelet counts and diabetes were identified as predictors of SVR among boceprevir patients, while early clearance of virus, IL28B, cirrhosis, HCV subtype, age, haemoglobin, bilirubin and albumin levels were identified as predictors of SVR for telaprevir patients. CONCLUSIONS: In academic and community centres, triple therapy including boceprevir or telaprevir led to SVR rates somewhat lower than those noted in large phase 3 clinical trials. Response rates were consistently higher among patients without cirrhosis compared to those with cirrhosis regardless of DAA used and prior treatment response. Trial registration clinicaltrials.gov NCT01474811.


Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Prolina/análogos & derivados , Adolescente , Adulto , Fatores Etários , Idoso , Algoritmos , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Biomarcadores , Comorbidade , Quimioterapia Combinada , Feminino , Genótipo , Humanos , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Oligopeptídeos/administração & dosagem , Oligopeptídeos/efeitos adversos , Polietilenoglicóis/uso terapêutico , Prolina/administração & dosagem , Prolina/efeitos adversos , Prolina/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Ribavirina/uso terapêutico , Adulto Jovem
8.
J Viral Hepat ; 19(6): 404-13, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22571902

RESUMO

To evaluate T cell immunity in advanced liver disease, antigen-specific lymphoproliferative (LP) responses were prospectively studied in the context of the Hepatitis C Antiviral Long-term Treatment against Cirrhosis trial. Peripheral blood responses to hepatitis C virus (HCV), tetanus and Candida protein antigens were measured at baseline, month 12 (M12), M24, M36 and M48 in 186 patients randomized to either low-dose peginterferon-alfa-2a (PEG-IFN) only or observation. Liver histology was evaluated at baseline, M24 and M48. Patients with cirrhosis (Ishak 5-6) were less likely to have positive LP responses to HCV at baseline than patients with fibrosis (15%vs 29%, P = 0.03) and had lower levels of HCV c100 responses at baseline, M24 and M48 (P = 0.11, P = 0.05, P = 0.02, respectively). For 97 patients with complete longitudinal data, the frequency of positive LP responses to HCV, tetanus and Candida antigens declined over time (P < 0.003), and the slope of this decline was greater in the PEG-IFN treatment group than the observation group (P < 0.02). Lower levels of tetanus LP responses were associated with fibrosis progression and clinical outcomes (P = 0.009). Poorer CD4+ T cell proliferative function was associated with more advanced liver disease in chronic hepatitis C and may be further affected by long-term PEG-IFN treatment.


Assuntos
Antígenos Virais/imunologia , Hepatite C Crônica/imunologia , Linfócitos T/imunologia , Antivirais/administração & dosagem , Candida/imunologia , Proliferação de Células , Feminino , Seguimentos , Hepatite C Crônica/tratamento farmacológico , Histocitoquímica , Humanos , Interferon-alfa/administração & dosagem , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/administração & dosagem , Proteínas Recombinantes/administração & dosagem , Toxina Tetânica/imunologia , Fatores de Tempo
9.
Aliment Pharmacol Ther ; 31(7): 719-34, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20070284

RESUMO

BACKGROUND: Primary analysis of the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) Trial showed long-term peginterferon therapy did not reduce complications in patients with chronic hepatitis C and advanced fibrosis or cirrhosis. AIM: To assess the effects of long-term peginterferon therapy and disease progression on health-related quality of life (HRQOL), symptoms and sexual health in HALT-C patients. METHODS: A total of 517 HALT-C patients received peginterferon alfa-2a (90 microg/week); 532 received no additional treatment for 3.5 years. Patients were followed up for outcomes of death, hepatocellular carcinoma and hepatic decompensation. Sexual health, SF-36 scores and symptoms were serially assessed by repeated-measures analyses of covariance. RESULTS: Patients with cirrhosis (n = 427) reported lower general well-being and more fatigue (P < 0.001) than patients with fibrosis (n = 622). Physical scores declined significantly over time, independent of treatment, and patients with cirrhosis reported lower scores. Vitality scores were lower in those with cirrhosis, and treated patients experienced a greater decline over time than untreated patients; HRQOL rebounded after treatment ended. Patients with a clinical outcome had significantly greater declines in all SF-36 and symptom scores. Among men, Sexual Health scores were significantly worse in treated patients and in those with a clinical outcome. CONCLUSION: Clinical progression of chronic hepatitis C and maintenance peginterferon therapy led to worsening of symptoms, HRQOL and, in men, sexual health in a large patient cohort followed up over 4 years (NCT00006164).


Assuntos
Antivirais/administração & dosagem , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/administração & dosagem , Cirrose Hepática/tratamento farmacológico , Polietilenoglicóis/administração & dosagem , Qualidade de Vida , Comportamento Sexual/efeitos dos fármacos , Adulto , Fadiga/complicações , Fadiga/psicologia , Feminino , Hepatite C Crônica/psicologia , Hepatite C Crônica/virologia , Humanos , Interferon alfa-2 , Cirrose Hepática/psicologia , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , Qualidade de Vida/psicologia , Proteínas Recombinantes , Comportamento Sexual/psicologia , Fatores Socioeconômicos
10.
J Viral Hepat ; 16(8): 595-604, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19243495

RESUMO

Hepatitis C virus (HCV) infections are treated with interferon alpha plus ribavirin, but it is unknown how ribavirin works against HCV. Ribavirin is a guanosine analogue that can be a substrate for the viral RNA polymerase. HCV is genetically variable, and this genetic variation could affect the polymerase's use of ribavirin triphosphate. Thirteen patients infected with HCV who failed interferon alpha monotherapy and were retreated with interferon alpha plus ribavirin were identified; seven were responders and six were nonresponders to combination therapy. The consensus sequences encoding the 13 polymerases plus seven sequences from treatment-naive controls were determined. The responder sequences were more genetically variable than the nonresponders and controls, the amino acid variations unique to responders had lower BLOSUM90 scores than variations in nonresponders and controls, and the amino acid variations correlated with response to therapy clustered around the RNA-binding channel of the polymerase. These data imply that that the responder enzymes were probably more functionally variable than the nonresponder enzymes. Enzymatic activity was measured for 10 recombinant polymerases; RNA synthesis activity varied by over sevenfold and polymerases from two of the responders used GTP much better than UTP, but technical limitations prevented direct measurement of ribavirin triphosphate use. Because response to combination therapy in these patients was primarily due to addition of ribavirin to the treatment regimen, these data imply that genetic variation in the polymerase may have affected the efficiency of ribavirin incorporation into the viral genome and hence may have modulated ribavirin's efficacy against HCV.


Assuntos
Antivirais/farmacologia , RNA Polimerases Dirigidas por DNA/metabolismo , Hepacivirus/efeitos dos fármacos , Ribavirina/farmacologia , Proteínas Virais/metabolismo , Sequência de Aminoácidos , RNA Polimerases Dirigidas por DNA/genética , Variação Genética , Hepatite C Crônica/tratamento farmacológico , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Estrutura Terciária de Proteína , RNA Viral/biossíntese , Ribavirina/uso terapêutico , Alinhamento de Sequência , Análise de Sequência de DNA , Proteínas Virais/genética
11.
J Viral Hepat ; 14(10): 721-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17875007

RESUMO

Patients infected with hepatitis C virus (HCV) genotype 1 and with serum HCV RNA concentrations over 800 000 IU/mL have relatively low rates of virologic response to pegylated interferons. The 2 forms of pegylated interferon have different pharmacokinetic profiles, and pilot studies comparing them have yielded varying results. We compared the virologic response to 12 weeks of treatment with peginterferon alpha-2a plus ribavirin vs peginterferon alpha-2b plus ribavirin in 380 patients who were infected with HCV genotype 1 and had high viral loads. We observed no between-group differences in viral load reduction over time and no differences in the percentage of patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin who achieved early virologic response (EVR), defined as >/=2-log reduction in HCV RNA concentration or undetectable HCV RNA at 12 weeks (66%vs 63%). Serum levels of interferon were more frequently below the level of quantitation in patients treated with peginterferon alpha-2b plus ribavirin (58-68%) than in those treated with peginterferon alpha-2a plus ribavirin (1-2%). Patients treated with peginterferon alpha-2b plus ribavirin had higher rates of discontinuation for safety reasons (6%vs 1%). In conclusion, a substantial percentage of patients infected with HCV genotype 1 and high viral load can achieve EVR when treated with peginterferon and ribavirin. The 2 pegylated interferons showed comparable anti-HCV activity during the first 12 weeks of treatment when combined with the same doses of ribavirin (1000-1200 mg/day), but discontinuations for safety reasons were higher in the patients treated with peginterferon alpha-2b plus ribavirin.


Assuntos
Antivirais/uso terapêutico , Hepacivirus/isolamento & purificação , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Quimioterapia Combinada , Feminino , Hepacivirus/genética , Hepatite C Crônica/sangue , Hepatite C Crônica/virologia , Humanos , Interferon alfa-2 , Interferons/sangue , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Proteínas Recombinantes , Fatores de Tempo , Carga Viral
12.
Braz. j. med. biol. res ; 37(5): 691-695, May 2004. ilus
Artigo em Inglês | LILACS | ID: lil-357556

RESUMO

Hepatitis C virus (HCV) was first described in 1989 as the putative viral agent of non-A non-B hepatitis. It is a member of the Flaviviridae family and has been recognized as the major causative agent of chronic liver disease, including chronic active hepatitis, cirrhosis and hepatocellular carcinoma. HCV is a positive RNA virus with a genome containing approximately 9500 nucleotides. It has an open reading frame that encodes a large polyprotein of about 3000 amino acids and is characterized by extensive genetic diversity. HCV has been classified into at least 6 major genotypes with many subtypes and circulates within an infected individual as a number of closely related but distinct variants known as quasispecies. This article reviews aspects of the molecular biology of HCV and their clinical implication.


Assuntos
Humanos , Regiões 3' não Traduzidas , Genoma Viral , Genótipo , Variação Genética , Biologia Molecular , Proteínas não Estruturais Virais , Proteínas Estruturais Virais
13.
Braz J Med Biol Res ; 37(5): 691-5, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15107931

RESUMO

Hepatitis C virus (HCV) was first described in 1989 as the putative viral agent of non-A non-B hepatitis. It is a member of the Flaviviridae family and has been recognized as the major causative agent of chronic liver disease, including chronic active hepatitis, cirrhosis and hepatocellular carcinoma. HCV is a positive RNA virus with a genome containing approximately 9500 nucleotides. It has an open reading frame that encodes a large polyprotein of about 3000 amino acids and is characterized by extensive genetic diversity. HCV has been classified into at least 6 major genotypes with many subtypes and circulates within an infected individual as a number of closely related but distinct variants known as quasispecies. This article reviews aspects of the molecular biology of HCV and their clinical implication.


Assuntos
Hepacivirus/genética , Biologia Molecular , Regiões 3' não Traduzidas/genética , Variação Genética , Genoma Viral , Genótipo , Humanos , Proteínas não Estruturais Virais/genética , Proteínas Estruturais Virais/genética
14.
Minerva Med ; 95(6): 529-34, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15785437

RESUMO

AIM: Osteodystrophy is a well known complication of cholestatic liver diseases such as primary biliary cirrhosis (PBC), although the factors predisposing to the development of metabolic bone disease and its natural history have not been well studied. METHODS: We followed a cohort of patients, predominantly post-menopausal females, for changes in bone mineral density over a period of up to 8 years. RESULTS: We found that most patients with PBC have relatively stable lumbar bone density over time, even in the face of progressive liver disease. Only 2 of 22 patients experienced fractures. Both of these patients had low initial bone density measurements. CONCLUSIONS: We recommend that all patients with newly diagnosed PBC undergo bone mineral density measurement so as to identify those at greatest risk of pathological fractures.


Assuntos
Densidade Óssea , Doenças Ósseas Metabólicas/fisiopatologia , Cirrose Hepática Biliar/fisiopatologia , Adulto , Idoso , Doenças Ósseas Metabólicas/etiologia , Feminino , Seguimentos , Fraturas Espontâneas/etiologia , Fraturas Espontâneas/fisiopatologia , Humanos , Cirrose Hepática Biliar/complicações , Masculino , Pessoa de Meia-Idade , Coluna Vertebral/fisiopatologia
15.
J Med Virol ; 70(1): 20-6, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12629639

RESUMO

A few hepatitis B virus (HBV) infections are characterized by the presence of HBV DNA in serum or liver tissue, or both, in the absence of detectable hepatitis B surface antigen (HBsAg) in serum. However, such infections have rarely been described previously in North American patients. In the present study, 31 hepatocellular carcinoma (HCC) patients from the United States and Canada who had no detectable HBsAg in their serum were studied. In these 31 HBsAg-negative HCC patients, HBV DNA was detected in HCC and/or in adjacent nontumorous liver tissue using nested polymerase chain reaction (PCR) in 5/9 (56%) patients from the United States and in 12/22 (55%) from Canada. The 17 HBV DNA-positive/HBsAg-negative patients from the United States and Canada included 9 without any serological markers for HBV and 8 with detectable antibodies to hepatitis B core antigen. In these patients, HBV genotype C was the most prevalent genotype (11/17; 64%). HBV genotypes have not been previously reported in HCC patients from North America. Replicative intermediate forms of HBV (covalently closed circular HBV DNA) were detected in 2/17 (12%) HBV DNA-positive/HBsAg-negative patients, indicating that at least two of these patients had actively replicating HBV infections. The use of tests to detect HBV DNA permitted the identification of HBV infections in HBsAg-negative HCC patients from North America. Among these patients, those with antibody to hepatitis C virus (HCV) would otherwise have been designated "HCV-associated HCCs" based on serological tests alone. These findings provide a new perspective on determining the possible viral etiologies of HCCs in North America.


Assuntos
DNA Viral/análise , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/genética , Hepatite B/imunologia , Sequência de Aminoácidos , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/virologia , Feminino , Genótipo , Hepatite B/genética , Vírus da Hepatite B/classificação , Vírus da Hepatite B/isolamento & purificação , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , América do Norte , Filogenia , Reação em Cadeia da Polimerase/métodos , Homologia de Sequência de Aminoácidos
17.
Gut ; 50(4): 443-5, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11889057

RESUMO

Hepatitis B virus is a major cause of morbidity and mortality worldwide. Effective therapies were first introduced in the mid-1980s but frequent and sometimes severe side effects limit their use. Combination therapy represents the future of treatment for chronic hepatitis B, probably consisting of two or more nucleoside analogues although interferon may form part of some combinations. New drugs acting by different antiviral mechanisms may be particularly potent in combination.


Assuntos
2-Aminopurina/análogos & derivados , Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , 2-Aminopurina/uso terapêutico , Quimioterapia Combinada , Famciclovir , Previsões , Humanos , Interferon-alfa/uso terapêutico , Lamivudina/uso terapêutico
18.
Minerva Med ; 92(6): 431-4, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11740431

RESUMO

Chronic infection with the hepatitis B virus infection remains a major problem worldwide despite some decrease in its incidence after improvement in public health policies and the utilization of hepatitis B vaccine. The clinical spectrum of the disease ranges from the asymptomatic carrier and individuals with mild liver injury to cirrhosis and hepatocellular carcinoma. During the past two decades there has been important progress in the field of viral hepatitis, and several drugs for the treatment of chronic hepatitis B have been developed and analyzed in clinical trials. Currently, two forms of therapy have been approved and are available for clinical practice: alpha interferon and lamivudine. Neither therapy is entirely satisfactory because of side effects and lack of universal responses. There is also controversy over which patients should be treated and what agent and regimen should be used. In this review we discuss the advantages and disadvantages of utilizing either drug, the response rates to therapy and what regimen should be used.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Interferons/uso terapêutico , Lamivudina/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Humanos
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