798 resultados para CHRONIC HEPATITIS-B
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High rates of hepatocellular carcinoma (HCC) in The Gambia, West Africa, are primarily due to a high prevalence of chronic hepatitis B virus infection and heavy aflatoxin exposure via groundnut consumption. We investigated genetic polymorphisms in carcinogen-metabolizing (GSTM1, GSTT1, HYL1*2) and DNA repair (XRCC1) enzymes in a hospital-based case-control study. Incident HCC cases (n = 216) were compared with frequency-matched controls (n = 408) with no clinically apparent liver disease. Although the prevalence of variant genotypes was generally low, in multivariable analysis (adjusting for demographic factors, hepatitis B virus, hepatitis C virus, and TP53 status), the GSTM1-null genotype [odds ratio (OR), 2.45; 95% confidence interval (95% CI), 1.21-4.95] and the heterozygote XRCC1-399 AG genotype (OR, 3.18; 95% CI, 1.35-7.51) were significantly associated with HCC. A weak association of the HYL1*2 polymorphism with HCC was observed but did not reach statistical significance. GSTT1 was not associated with HCC. The risk for HCC with null GSTM1 was most prominent among those with the highest groundnut consumption (OR, 4.67; 95% CI, 1.45-15.1) and was not evident among those with less than the mean groundnut intake (OR, 0.64; 95% Cl, 0.20-2.02). Among participants who had all three suspected aflatoxin-related high-risk genotypes [GSTM1 null, HLY1*2 (HY/HH), and XRCC1 (AG/GG)], a significant 15-fold increased risk of HCC was observed albeit with imprecise estimates (OR, 14.7; 95% CI, 1.27-169). Our findings suggest that genetic modulation of carcinogen metabolism and DNA repair can alter susceptibility to HCC and that these effects may be modified by environmental factors.
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Background: Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B infection is associated with an increased risk of cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Our aim is to analyze, through a mathematical model, the potential impact of anti-HBV vaccine in the long-term (that is, decades after vaccination) number of LT. Methods: The model simulated that the prevalence of HBV infection was 0.5% and that approximately 20% of all the liver transplantation carried out in the state of Sao Paulo are due to HBV infection. Results: The theoretical model suggests that a vaccination program that would cover 80% of the target population would reach a maximum of about 14% reduction in the LT program. Conclusion: Increasing the vaccination coverage against HBV in the state of Sao Paulo would have a relatively low impact on the number of liver transplantation. In addition, this impact would take several decades to materialize due to the long incubation period of liver failure due to HBV.
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BACKGROUND: 90% of newborns infected perinatally will develop chronic hepatitis B infection with the risk of liver cirrhosis or hepatocellular carcinoma. In Switzerland, screening of all pregnant women for hepatitis B virus (HBV) has been recommended since 1983. Neonates at risk for perinatally acquired HBV are passively and actively immunised immediately after birth as well as at 1 and 6 months of age. The objective of this study was to evaluate the proportion of newborns immunised in accordance with the proposed vaccination schedule. METHODS: Patient records of 3997 mothers who gave birth to a liveborn infant during a two-year period at Zürich University Hospital were screened by computer. 128 women were identified as HBsAg positive or anti-HBc alone positive. Of 133 infants born to these mothers, complete data were available for 94 (71%). RESULTS: Immunisation was started in 88 infants (94%), but only in 78 (83%) within the first 24 hours of life. 85 (90%) received the 2nd immunisation but only 72 (77%) within the given time limit. 80 (85%) of the infants received the 3rd immunisation but only 69 (73%) within the correct time limit. In summary, only 51 (54%) of the infants at risk for HBV infection were immunised correctly (immunoglobulin within 24 hours and active prophylaxis at 0, 1 and 6 months). CONCLUSIONS: The success of the immunisation strategy following maternal screening and selective immunisation of newborns at risk for HBV infection is limited for various reasons (lack of screening results at birth, problems with correct documentation and communication). To overcome these drawbacks, selective vaccination strategy should be improved and general vaccination strategy, including infants, should be reconsidered.
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BACKGROUND Chronic hepatitis B virus (HBV) infection affects up to 7 % of the European population. Specific HBV genotypes are associated with rapid progression to end-stage liver disease and sub-optimal interferon treatment responses. Although the geographic distribution of HBV genotypes differs between regions, it has not been studied in Switzerland, which lies at the crossroads of Europe. METHODS In a retrospective analysis of 465 HBV samples collected between 2002 and 2013, we evaluated the HBV genotype distribution and phylogenetic determinants, as well as the prevalence of serological evidence of hepatitis delta, hepatitis C and HIV infections in Switzerland. Baseline characteristics of patients were compared across their region of origin using Fisher's exact test and ANOVA, and risk factors for HBeAg positivity were assessed using logistic regression. RESULTS The Swiss native population represented 15.7 % of HBV-infected patients living in Switzerland. In the overall population, genotype D was most prevalent (58.3 %), whereas genotype A (58.9 %) was the predominant genotype among the Swiss native population. The prevalence of patients with anti-HDV antibodies was 4.4 %. Patients of Swiss origin were most likely to be HBeAg-positive (38.1 %). HBV genotypes of patients living in Switzerland but sharing the same original region of origin were consistent with their place of birth. CONCLUSIONS The molecular epidemiology of HBV infection in Switzerland is driven by migration patterns and not by the genotype distribution of the native population. The prevalence of positive anti-HDV antibodies in our cohort was very low.
Resumo:
Der natürliche Verlauf einer HepatitisB-Virus(HBV)-Infektion ist komplex und wird einerseits durch das Alter zum Zeitpunkt der Infektion, anderseits durch Komorbiditäten bzw. Koinfektionen und zum Teil noch nicht identifizierte Faktoren bestimmt. Das HBV wird nie komplett eliminiert. Das Erreichen des inaktiven Trägerstatus ist aber ein realistisches Therapieziel. Zur Therapie stehen Nukleosid/NukleotidAnaloga sowie pegyliertes Interferonalpha zur Verfügung. Screening von bestimmten Patientengruppen und eine generelle Impfung sind wichtige prophylaktische Massnahmen. Die chronische Hepatitis-C-Virus(HCV) -Infektion führt in circa einem Drittel der Fälle zur Leberzirrhose. Eine Therapie ist generell ab Fibrosestadium Metavir 2 indiziert. Neue DAA (directly acting antivirals) erlauben kurzfristige, hochpotente und nebenwirkungsarme Therapieschemata.
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Treatment of chronic hepatitis B virus (HBV) infections with the reverse transcriptase inhibitor lamivudine leads to a rapid decline in plasma viremia and provides estimates for crucial kinetic constants of HBV replication. We find that in persistently infected patients, HBV particles are cleared from the plasma with a half-life of approximately 1.0 day, which implies a 50% daily turnover of the free virus population. Total viral release into the periphery is approximately 10(11) virus particles per day. Although we have no direct measurement of the infected cell mass, we can estimate the turnover rate of these cells in two ways: (i) by comparing the rate of viral production before and after therapy or (ii) from the decline of hepatitis B antigen during treatment. These two independent methods give equivalent results: we find a wide distribution of half-lives for virus-producing cells, ranging from 10 to 100 days in different patients, which may reflect differences in rates of lysis of infected cells by immune responses. Our analysis provides a quantitative understanding of HBV replication dynamics in vivo and has implications for the optimal timing of drug treatment and immunotherapy in chronic HBV infection. This study also represents a comparison for recent findings on the dynamics of human immunodeficiency virus (HIV) infection. The total daily production of plasma virus is, on average, higher in chronic HBV carriers than in HIV-infected patients, but the half-life of virus-producing cells is much shorter in HIV. Most strikingly, there is no indication of drug resistance in HBV-infected patients treated for up to 24 weeks.
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Helper T (Th) cells are classified as Th1 or Th2 cells by virtue of cytokine secretion and function as mediators of cellular or humoral immunity, respectively. Cytokines also regulate the differentiation of Th cells. For example, interleukin (IL)-12 promotes Th1 and suppresses Th2 cell development, suggesting that IL-12 may be useful therapeutically in Th2-mediated autoimmune and allergic disorders. Therefore, the effect of systemic IL-12 treatment on in vivo autoantibody synthesis in hepatitis B e antigen (HBeAg)-expressing transgenic mice, which is dependent on self-reactive Th2 cells, was examined. Low-dose IL-12 significantly inhibited autoantibody production by shifting the Th2-mediated response toward Th1 predominance. Additionally, previous studies suggest that a predominance of HBeAg-specific Th2-type cells may contribute to chronicity in hepatitis B virus infection. Therefore, IL-12 may also prove beneficial in modulating the HBeAg-specific Th response to favor viral clearance in chronic hepatitis B virus infection.
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Studies of 4 to 6 months of treatment with interferon for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B virus (HBV) infection have shown clearance of HBeAg to be higher in treated patients than it is in controls by approximately 25%. These results are considerably better than those with antiviral agents. Therefore, the recent European Association for the Study of the Liver (EASL) Consensus Committee recommended the use of interferon alpha for this condition. Treatment with pegylated interferons in several trials has shown better results still. Lamivudine in combination with interferon, however, did not improve the results at 6 months after the end of therapy. In HBeAg-negative chronic HBV infection, pegylated interferon alpha is superior to lamivudine, and, again, combination with lamivudine does not improve the results. Side effects in all studies have been tolerable. Thus, these observations in chronic HBV infection, whether HBeAg-positive or HBeAg-negative, suggest an important, even primary, role for pegylated interferon therapy.
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The prevalence rate of hepatitis B virus (HBV) infection in Pacific Island countries is amongst the highest in the world. Hepatitis B immunisation has been incorporated into national programmes at various times, often with erratic supply and coverage, until a regionally co-ordinated programme, which commenced in 1995 ensured adequate supply. The effectiveness of these programmes was recently evaluated in four countries, Vanuatu and Fiji in Melanesia, Tonga in Polynesia and Kiribati in Micronesia. That evaluation established that the programmes had a substantial beneficial impact in preventing chronic hepatitis B infection [Vaccine 18 (2000) 3059]. Several studies of hepatitis B vaccination programmes in endemic countries have identified the potential significance of surface gene mutants as a cause for failure of immunisation. In the study outlined in this paper, we screened infected children and their mothers for the emergence and prevalence of these variants in specimens collected from the four country evaluation. Although the opportunity for the emergence of HBV vaccine escape mutants in these populations was high due to the presence of a considerable amount of the virus in the population and the selection pressure from vaccine use, there were no a determinant vaccine escape mutants found. This suggests that vaccine escape variants are not an important cause for failure to prevent HBV transmission in this setting. Other HBsAg variants were detected, but their functional significance remains to be determined. The failure to provide satisfactory protection during such immunisation programmes reflects the need for achieving and sustaining high vaccine coverage, improving the timeliness of doses as well as improving 'cold-chain' support, rather than the selection of vaccine-escape mutants of HBV. (C) 2004 Elsevier Ltd. All rights reserved.
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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.
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Background: Globally, chronic B viral hepatitis (HBV) is a major health problem. Obesity is a common problem among patients with HBV. Several studies have reported that obesity is an important risk factor that alters immune system response in individuals with no underlying cause of liver disease. However, there is a strong association between BMI and the human immune system among HBV patients. Objective: This study was to examine the correlation between body mass index, serum alanine aminotransferase activity (ALT) and immunologic response in obese hepatitis B patients. Material and methods: One hundred fifty male patients with chronic hepatitis B virus, their age ranged from 30 to 45 (38.64 ± 7.12) years and their BMI ranged from 30-35 kg/m2. All Subjects were included in two groups: The first group received weight reduction program in the form of treadmill aerobic exercises in addition to diet control whereas the second group received no therapeutic intervention. Parameters of serum alanine aminotransferase (ALT), CD3, CD4 and CD8 were quantified; Leukocyte, differential counts and body mass index (BMI) were measured before and after 3 months at the end of the study. Results: There was a 24.7%, 36.8%, 30.8%, 40.7%, 28.6%, 25.9%, 33.3% and 14.3 % reduction in mean values of alanine aminotransferase (ALT), white blood cells, total neutrophil count, monocytes, CD3, CD4 ,CD8 and BMI respectively in group (A) at the end of the study. In addition, there were significant differences between mean levels of the investigated parameters in groups. Conclusion: Based on our findings, weight loss modulates serum alanine aminotransferase and immune system parameters of patients with hepatitis B virus infection.
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Chronic liver disease in human immunodeficiency virus (HIV)-infected patients is mostly caused by hepatitis virus co-infection. Other reasons for chronic alanine aminotransferase (ALT) elevation are more difficult to diagnose.
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Transgenic mice expressing the sequences coding for the envelope proteins of the hepatitis B virus (HBV) in the liver have been used as a model of the HBV chronic carrier state. We evaluated the possibility of inducing a specific immune response to the viral envelope antigens and thus potentially controlling chronic HBV infection. Using HBV-specific DNA-mediated immunization in this transgenic model, we show that the immune response induced after a single intramuscular injection of DNA resulted in the complete clearance of circulating hepatitis B surface antigen and in the long-term control of transgene expression in hepatocytes. This response does not involve a detectable cytopathic effect in the liver. Adoptive transfer of fractionated primed spleen cells from DNA-immunized mice shows that T cells are responsible for the down-regulation of HBV mRNA in the liver of transgenic mice. To our knowledge, this is the first demonstration of a potential immunotherapeutic application of DNA-mediated immunization against an infectious disease and raises the possibility of designing more effective ways of treating HBV chronic carriers.
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We present a rare case of a 23-year-old male incidentally detected with hepatitis B virus (HBV) infection presenting with features suggestive of HBV-associated nephropathy. A renal biopsy specimen suggested a mesangioproliferative glomerulonephritis with a full-house pattern on immunoflourescence consistent with a diagnosis of diffuse lupus nephritis. Glomerular HbeAg and HbsAg antigens were not detectable by immunofluorescence. Antiviral therapy was instituted to suppress viral replication, thereby leading to clinical and virological remission, including that of the glomerulonephritis, without the need for additional immunosuppressant therapy. This case depicts the uniqueness of the presentation of the two conditions mimicking each other, the strategy adopted to prevent the activation of viral replication and the achievement of clinical remission.
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AIM: To evaluate pretreatment hepatitis B virus (HBV) testing, vaccination, and antiviral treatment rates in Veterans Affairs patients receiving anti-CD20 Ab for quality improvement. METHODS: We performed a retrospective cohort study using a national repository of Veterans Health Administration (VHA) electronic health record data. We identified all patients receiving anti-CD20 Ab treatment (2002-2014). We ascertained patient demographics, laboratory results, HBV vaccination status (from vaccination records), pharmacy data, and vital status. The high risk period for HBV reactivation is during anti-CD20 Ab treatment and 12 mo follow up. Therefore, we analyzed those who were followed to death or for at least 12 mo after completing anti-CD20 Ab. Pretreatment serologic tests were used to categorize chronic HBV (hepatitis B surface antigen positive or HBsAg+), past HBV (HBsAg-, hepatitis B core antibody positive or HBcAb+), resolved HBV (HBsAg-, HBcAb+, hepatitis B surface antibody positive or HBsAb+), likely prior vaccination (isolated HBsAb+), HBV negative (HBsAg-, HBcAb-), or unknown. Acute hepatitis B was defined by the appearance of HBsAg+ in the high risk period in patients who were pretreatment HBV negative. We assessed HBV antiviral treatment and the incidence of hepatitis, liver failure, and death during the high risk period. Cumulative hepatitis, liver failure, and death after anti-CD20 Ab initiation were compared by HBV disease categories and differences compared using the χ(2) test. Mean time to hepatitis peak alanine aminotransferase, liver failure, and death relative to anti-CD20 Ab administration and follow-up were also compared by HBV disease group. RESULTS: Among 19304 VHA patients who received anti-CD20 Ab, 10224 (53%) had pretreatment HBsAg testing during the study period, with 49% and 43% tested for HBsAg and HBcAb, respectively within 6 mo pretreatment in 2014. Of those tested, 2% (167/10224) had chronic HBV, 4% (326/7903) past HBV, 5% (427/8110) resolved HBV, 8% (628/8110) likely prior HBV vaccination, and 76% (6022/7903) were HBV negative. In those with chronic HBV infection, ≤ 37% received HBV antiviral treatment during the high risk period while 21% to 23% of those with past or resolved HBV, respectively, received HBV antiviral treatment. During and 12 mo after anti-CD20 Ab, the rate of hepatitis was significantly greater in those HBV positive vs negative (P = 0.001). The mortality rate was 35%-40% in chronic or past hepatitis B and 26%-31% in hepatitis B negative. In those pretreatment HBV negative, 16 (0.3%) developed acute hepatitis B of 4947 tested during anti-CD20Ab treatment and follow-up. CONCLUSION: While HBV testing of Veterans has increased prior to anti-CD20 Ab, few HBV+ patients received HBV antivirals, suggesting electronic health record algorithms may enhance health outcomes.