952 resultados para Hepatitis B, Chronic


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The detection of HBV-DNA in serum by molecular hybridization is the most sensitive and specific marker of replication and infectivity of hepatitis B virus and currently is proposed as a routine diagnostic technique in the follow-up of HBV - related diseases. Comparing different techniques already described, we found that direct spotting of serum samples on nitrocellulose membranes under vacuum filtration, followed by denaturing and neutralizing washes is more practical, simple, sensible and reproducible. DNA polymerase assay using phosphonoformic acid as specific viral inhibitor has shown 86.8% of concordance with HBV-DNA detection, and so, it is an useful alternative in the follow-up of hepatitis B chronic patients. We found 19.2% HBeAg positive samples with no other markers of viral replication and no anti-HBe positive sample had detectable HBV-DNA. Discordance between the 2 systems have been extensively described, and we confirm this for the first time in our country. Molecular biological techniques are essential to determine the replication status of chronic hepatitis B patients.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Lamivudine has been demonstrated safe and efficacious in the short term in a large cohort of children with chronic hepatitis B (CHB), but optimal duration of treatment has not been elucidated and limited data on the safety of long-term lamivudine administration have been reported. In addition, the durability of favourable therapeutic outcomes after lamivudine therapy in children has not been well characterized. The aim of this study was to examine the safety of lamivudine and the durability of clinical responses in a group of children who received up to 3 years of treatment for CHB. One hundred and fifty-one children from centres in nine countries who had previously received lamivudine in a large prospective trial were enrolled. During the first year, children had been randomized to either lamivudine or placebo treatment. Subsequently, in a separate extension study, those who remained hepatitis B e antigen (HBeAg) positive were given lamivudine for up to 2 years and those who were HBeAg negative were observed for additional 2 years. Results of these studies have been previously reported. In this study, these children were followed for 2 additional years. Data gathered from medical record review included weight, height, signs and symptoms of hepatitis, alanine aminotransferase (ALT) levels, serologic markers, hepatitis B virus (HBV) DNA levels and serious adverse events (SAEs). Other pharmacological treatments for CHB were allowed according to the practices of individual investigators and were documented. Subjects were divided into two groups for analysis, those who had achieved virological response (VR), defined as HBeAg negative and undetectable HBV DNA by the bDNA assay by the end of the extension study at 3 years, and those who had not. In those who had achieved VR by the end of the extension study, long-term durability of HBeAg seroconversion was 82% and >90% in those who had received lamivudine for 52 weeks and at least 2 years respectively. This compares to 75% for those who had achieved seroconversion after placebo. In those who had not achieved VR by the end of the extension study, an additional 11% did so by the end of the study; they had all received lamivudine in the previous trial, and none had received further treatment during the study. Eight children lost hepatitis B surface antigen during the study and all had received lamivudine at some point during the previous trials. Evaluation of safety data revealed no SAEs related to lamivudine. There was no effect of treatment on weight or height z scores. Clinically benign ALT flares (>10 times normal) were seen in 2% of children. Favourable outcomes from lamivudine treatment of CHB in children are maintained for at least several years after completion of treatment. Up to 3 years of lamivudine treatment is safe in children.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Data on the association of schistosomiasis and hepatitis B in field-based studies are scarce. Two areas have been selected for this study: i) Queixadinha, endemic for schistosomiasis, with a population of 693 individuals, and ii) Capão, a control non-endemic area, with 515 inhabitants. Sera of all individuals in both areas were tested for hepatitis B infection, yearly, from 1994 to 1997. In the first area hepatitis B was found in 32.1% of children up to one year old and reached a peak of 68.7% in the age range of 15 to 19 years. In the control area the prevalence of hepatitis B was under 5% up to 19 years of age and the highest prevalence was observed in adults over 45. HBsAg was detected in 9.4% of the individuals living in the endemic area for schistosomiasis and in 1.4% of the controls (OR=4.98; 95%CI=3.7-6.7). The index of chronicity of HBsAg was not statistically different in the studied areas (8.1% x 7.3%; OR = 1.09; 95%CI= 0.42-3.03), nor was it different for people with and without schistosomiasis in Queixadinha (8.7% x 7.0%). We conclude that the Schistosoma mansoni infection has not altered the course of hepatitis B in the studied area.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Since the arrival of several new antivirals and due to the growing molecular and clinical knowledge of hepatitis B virus (HBV) infection, therapy of hepatitis B has become complex. Clinical guidelines aim at streamlining medical attitudes: in this respect, the European Association for the Study of the Liver (EASL) recently issued clinical practice guidelines for the management of chronic hepatitis B. Guidelines made by international experts need however to be adapted to local health care systems. Here, we summarise the EASL guidelines with some minor modifications in order to be compatible with the particular Swiss situation, while discussing in more detail some aspects. Chronic hepatitis B is a complex disease with several phases where host and viral factors interact: the features of this continuous interplay need to be evaluated when choosing the most appropriate treatment. The EASL guidelines recommend, as first-line agents, using the most potent antivirals available with the optimal resistance profile, in order to abate HBV DNA as rapidly and as sustainably as possible. Once therapy has been started, the infection evolves and resistant viral strains may emerge. Rescue therapy needs to be started early with more potent agents lacking cross-resistance.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Chronic hepatitis B predisposes to the development of cirrhosis and hepatocellular carcinoma. Treatment of chronic hepatitis B is aimed at halting viral replication and, thereby, hepatic inflammation. Treatment indication should be established carefully and with full knowledge of the advantages and limitations of currently available antiviral drugs. Patients on long-term nudcleos(t)ide analogue treatment should be followed regularly in order to avoid the appearance of antiviral resistance. The purpose of this review is to provide a concise overview of the diagnosis and management of chronic hepatitis B.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Treatment options for chronic hepatitis B have significantly expanded over the last decade. Six nucleoside or nucleotide analogs (NA) with activity against the hepatitis B virus are currently available. Prolonged NA treatment is required in many cases to maintain viral suppression, with an inherent risk of the development of antiviral resistance. The purpose of this concise review is to provide an introduction to the prevention, diagnosis and management of antiviral resistance in chronic hepatitis B.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Chronic hepatitis B virus (HBV) infection is responsible for up to 30% of cases of liver cirrhosis and up to 53% of cases of hepatocellular carcinoma. Liver transplantation (LT) is the best therapeutic option for patients with end-stage liver failure caused by HBV. The success of transplantation, though, depends on receiving prophylactic treatment against post-transplant viral reactivation. In the absence of prophylaxis, liver transplantation due to chronic hepatitis B (CHB) is associated with high rates of viral recurrence and poor survival. The introduction of treatment with hepatitis B immunoglobulins (HBIG) during the 1990s and later the incorporation of oral antiviral drugs have improved the prognosis of these patients. Thus, LT for CHB is now a universally accepted option, with an estimated 5 years survival of around 85% vs the 45% survival seen prior to the introduction of HBIG. The combination of lamivudine plus HBIG has for many years been the most widely used prophylactic regimen. However, with the appearance of new more potent oral antiviral agents associated with less resistance (e.g., entecavir and tenofovir) for the treatment of CHB, new prophylactic strategies are being designed, either in combination with HBIG or alone as a monotherapy. These advances have allowed for more personalized prophylaxis based on the individual risk profile of a given patient. In addition, the small pool of donors has required the use of anti-HBc-positive donors (with the resulting possibility of transmitting HBV from these organs), which has been made possible by suitable prophylactic regimens.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

More than 5% of the world's population lives with chronic hepatitis B. Migrants, particularly asylum seekers, are mostly from middle and high endemic regions. In Switzerland, however, no systematic screening of chronic hepatitis B is proposed to them. In a resolution published in 2010 the WHO encourages vaccination, but also screening of people at risk, as well as care of infected individuals. On the basis of a study conducted in asylum seekers in the canton of Vaud, prevalence of Ac antiHBc is estimated at 42% and HBsAg at 8%. Possible screening strategies and care are discussed in the light of these data. Identifying infected migrants would give them access to medical care and therefore lower the rate of complications, as well as the transmission of the virus between migrants and the local population.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background and aims: The prevalence of anti-HCV and HBsAg in Portugal has been shown to be elevated in high-risk groups, such as intravenous drug-users and incarcerated individuals. However, in the general population, prevalence remains largely unknown. The aims of this study were to estimate the prevalence of anti-HCV and HBsAg in the general Portuguese population and identify associated risk factors. Materials and methods: We carried out a nationwide, population-based cross-sectional study of adults resident in mainland Portugal. Serology for HBsAg, anti-HBc, anti-HBs, and anti-HCV was performed. Anti-HCV-positive individuals were tested for HCV RNA by PCR. Results: Of 1685 participants, 50.6% were men, mean age 50.2±18.3 years. In terms of hepatitis C, the prevalence of anti-HCV was 0.54% [95% confidence interval (CI): 0.2–0.9] and 0.12% (95% CI: 0.0–0.3) were viremic, with peak prevalence among individuals 35–64 years of age (0.8%), men (0.8%), and individuals from Lisbon and Tagus Valley region (1.9%). In terms of hepatitis B, the estimated prevalence of HBsAg was 1.45% (95% CI: 0.9–2.0). A higher prevalence was found in individuals who were 35–64 years old (2.2%), in men (2.5%), and in the Northern region (2.6%). The presence of positive serological markers of hepatitis C virus and hepatitis B virus infection did not correlate with elevated aminotransferases, race, place of birth, and alcohol consumption. Conclusion: These results suggest a low endemicity for both hepatitis B and hepatitis C in the general population, in contrast to a very high prevalence in risk groups, thus suggesting that targeted screening to high-risk groups may be more cost-effective than general population screening.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: HBV-HIV co-infection is associated with an increased liver-related morbidity and mortality. However, little is known about the natural history of chronic hepatitis B in HIV-infected individuals under highly active antiretroviral therapy (HAART) receiving at least one of the two drugs that also affect HBV (TDF and LAM). Information about HBeAg status and HBV viremia in HIV/HBV co-infected patients is scarce. The objective of this study was to search for clinical and virological variables associated with HBeAg status and HBV viremia in patients of an HIV/HBV co-infected cohort. Methods: A retrospective cross-sectional study was performed, of HBsAg-positive HIV-infected patients in treatment between 1994 and 2007 in two AIDS outpatient clinics located in the Sao Paulo metropolitan area, Brazil. The baseline data were age, sex, CD4 T+ cell count, ALT level, HIV and HBV viral load, HBV genotype, and duration of antiretroviral use. The variables associated to HBeAg status and HBV viremia were assessed using logistic regression. Results: A total of 86 HBsAg patients were included in the study. Of these, 48 (56%) were using combination therapy that included lamivudine (LAM) and tenofovir (TDF), 31 (36%) were using LAM monotherapy, and 7 patients had no previous use of either one. Duration of use of TDF and LAM varied from 4 to 21 and 7 to 144 months, respectively. A total of 42 (48. 9%) patients were HBeAg positive and 44 (51. 1%) were HBeAg negative. The multivariate analysis revealed that the use of TDF for longer than 12 months was associated with undetectable HBV DNA viral load (serum HBV DNA level < 60 UI/ml) (p = 0. 047). HBeAg positivity was associated with HBV DNA > 60 UI/ml (p = 0. 001) and ALT levels above normality (p = 0. 038). Conclusion: Prolonged use of TDF containing HAART is associated with undetectable HBV DNA viral load. HBeAg positivity is associated with HBV viremia and increased ALT levels.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Serum hepatitis B virus (HBV) DNA [eve[ is a predictor of the development of cirrhosis and hepatocellullar carcinoma in chronic hepatitis B patients. Nevertheless, the distribution of viral load levels in chronic HBV patients in Brazil has yet to be described. This cross-sectional study included 564 participants selected in nine Brazilian cities located in four of the five regions of the country using the database of a medical diagnostics company. Admission criteria included hepatitis B surface antigen seropositivity, availability of HBV viral toad samples and age >= 18 years. Mates comprised 64.5% of the study population. Mean age was 43.7 years. Most individuals (62.1%) were seronegative for the hepatitis B e antigen (HBeAg). Median serum ALT level was 34 U/L. In 58.5% of the patients HBV-DNA levels ranged from 300 to 99,999 copies/mL; however, in 21.6% levels were undetectable. Median HBV-DNA level was 2,351 copies/mL. Over 60% of the patients who tested negative for HBeAg and in whom ALT level was less than 1.5 times the upper limit of the normal range had HBV-DNA levels > 2,000 IU/mL, which has been considered a cut-off point for indicating a liver biopsy and/or treatment. In conclusion, HBV-DNA level identified a significant proportion of Brazilian individuals with chronic hepatitis B at risk of disease progression. Furthermore, this tool. enables those individuals with high HBV-DNA levels who are susceptible to disease progression to be identified among patients with normal or stightly elevated ALT.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Molecular epidemiological data concerning the hepatitis B virus (HBV) in Chile are not known completely. Since the HBV genotype F is the most prevalent in the country, the goal of this study was to obtain full HBV genome sequences from patients infected chronically in order to determine their subgenotypes and the occurrence of resistance-associated mutations. Twenty-one serum samples from antiviral drug-naive patients with chronic hepatitis B were subjected to full-length PCR amplification, and both strands of the whole genomes were fully sequenced. Phylogenetic analyses were performed along with reference sequences available from GenBank (n = 290). The sequences were aligned using Clustal X and edited in the SE-AL software. Bayesian phylogenetic analyses were conducted by Markov Chain Monte Carlo simulations (MCMC) for 10 million generations in order to obtain the substitution tree using BEAST. The sequences were also analyzed for the presence of primary drug resistance mutations using CodonCode Aligner Software. The phylogenetic analyses indicated that all sequences were found to be the HBV subgenotype F1b, clustered into four different groups, suggesting that diverse lineages of this subgenotype may be circulating within this population of Chilean patients. J. Med. Virol. 83: 1530-1536, 2011. (C) 2011 Wiley-Liss, Inc.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Sustained virologic suppression is a primary goal of therapy for chronic hepatitis B (CHB). In study entecavir (ETV)-022, 48 weeks of entecavir 0.5 mg was superior to lamivudine for virologic suppression for hepatitis B e antigen (HBeAg)-positive CHB. A total of 183 entecavir-treated patients from ETV-022 subsequently enrolled in study ETV-901. We present the results after up to 5 years (240 weeks) of continuous entecavir therapy. The entecavir long-term cohort consists of patients who received >= 1 year of entecavir 0.5 mg in ETV-022 and then entered ETV-901 with a treatment gap <= 35 days. In ETV-901 the entecavir dose was 1.0 mg daily. For patients with samples available at Year 5, proportions with hepatitis B virus (HBV) DNA <300 copies/mL, normal alanine aminotransferase (ALT) levels, HBeAg loss, and HBeAg seroconversion were determined. In all, 146 patients met criteria for inclusion in the entecavir long-term cohort. At Year 5, 94% (88/94) had HBV DNA <300 copies/mL and 80% (78/98) had normal ALT levels. In addition to patients who achieved serologic responses during study ETV-022, 23% (33/141) achieved HBeAg seroconversion and 1.4% (2/145) lost hepatitis B surface antigen (HBsAg) during study ETV-901. Through 5 years, entecavir resistance emerged in one patient. The safety profile of entecavir was consistent with previous reports. Conclusion: Extended therapy with entecavir through 5 years maintained or increased rates of HBV DNA suppression and ALT normalization. Additional patients also achieved HBeAg loss and seroconversion. Entecavir provides sustained viral suppression with minimal resistance during long-term treatment of HBeAg-positive CHB. (HEPATOLOGY 2010;51:422-430.)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As the mechanisms leading to the persistence of hepatitis B virus (HBV) infection are poorly understood and as the histocompatibility leucocyte antigen (HLA)-G is well described as a tolerogenic molecule, we evaluated HLA-G expression in 74 specimens of HBV liver biopsies and in 10 specimens obtained from previously healthy cadaver liver donors. HBV specimens were reviewed and classified by the METAVIR score, and HLA-G expression was assessed by immunohistochemistry. No HLA-G expression was observed in control hepatocytes. In contrast, 57 (77%) of 74 HBV specimens showed soluble and membrane-bound HLA-G expression in hepatocytes, biliary epithelial cells or both. No associations between the intensity of HLA-G expression and patient age or gender, HBeAg status, severity of liver fibrosis, and grade of histological findings were observed. Although significance was not reached (P = 0.180), patients exhibiting HLA-G expression presented a higher median HBV DNA viral load (105 copies/mL) than those who did not express HLA-G (103.7 copies/mL). These results indicate that HLA-G is expressed in most cases of chronic HBV infection in all stages and may play a role in the persistency of HBV infection.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Despite a large number of T cells infiltrating the liver of patients with chronic hepatitis B, little is known about their complexity or specificity. To characterize the composition of these T cells involved with the pathogenesis of chronic hepatitis B (CHB), we have studied the clonality of V beta T cell receptor (TCR)-bearing populations in liver tissue by size spectratyping the complementarity-determining region (CDR3) lengths of TCR transcripts. We have also compared the CDR3 profiles of the lymphocytes infiltrating the liver with those circulating in the blood to see whether identical clonotypes may be detected that would indicate a virus-induced expansion in both compartments. Our studies show that in most of the patients examined, the T cell composition of liver infiltrating lymphocytes is highly restricted, with evidence of clonotypic expansions in 4 to 9 TCR V beta subfamilies. In contrast, the blood compartment contains an average of 1 to 3 expansions. This pattern is seen irrespective of the patient's viral load or degree of liver pathology. Although the TCR repertoire profiles between the 2 compartments are generally distinct, there is evidence of some T cell subsets being equally distributed between the blood and the liver. Finally, we provide evidence for a putative public binding motif within the CDR3 region with the sequence G-X-S, which may be involved with hepatitis B virus recognition.