5 resultados para Hepatitis B.
em Université de Lausanne, Switzerland
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.
Resumo:
Introduction/objectives: Multipatient use of a single-patient CBSD occurred inan outpatient clinic during 4 to 16 months before itsnotification. We looked for transmission of blood-bornepathogens among exposed patients.Methods: Exposed patients underwent serology testing for HBV,HCV and HIV. Patients with isolated anti-HBc receivedone dose of hepatitis B vaccine to look for a memoryimmune response. Possible transmissions were investigatedby mapping visits and sequencing of the viral genomeif needed.Results: Of 280 exposed patients, 9 had died without suspicionof blood-borne infection, 3 could not be tested, and 5declined investigations. Among the 263 (93%) testedpatients, 218 (83%) had negative results. We confirmeda known history of HCV infection in 6 patients (1 coinfectedby HIV), and also identified resolved HBVinfection in 37 patients, of whom 18 were alreadyknown. 2 patients were found to have a previouslyunknown HCV infection. According to the time elapsedfrom the closest previous visit of a HCV-infected potentialsource patient, we could rule out nosocomial transmissionin one case (14 weeks) but not in the other (1day). In the latter, however, transmission was deemedvery unlikely by 2 reference centers based on thesequences of the E1 and HVR1 regions of the virus.Conclusion: We did not identify any transmission of blood-bornepathogens in 263 patients exposed to a single-patientCBSD, despite the presence of potential source cases.Change of needle and disinfection of the device betweenpatients may have contributed to this outcome.Although we cannot exclude transmission of HBV, previousacquisition in endemic countries is a more likelyexplanation in this multi-national population.
Resumo:
BACKGROUND & AIMS: Hepatitis C virus (HCV) induces chronic infection in 50% to 80% of infected persons; approximately 50% of these do not respond to therapy. We performed a genome-wide association study to screen for host genetic determinants of HCV persistence and response to therapy. METHODS: The analysis included 1362 individuals: 1015 with chronic hepatitis C and 347 who spontaneously cleared the virus (448 were coinfected with human immunodeficiency virus [HIV]). Responses to pegylated interferon alfa and ribavirin were assessed in 465 individuals. Associations between more than 500,000 single nucleotide polymorphisms (SNPs) and outcomes were assessed by multivariate logistic regression. RESULTS: Chronic hepatitis C was associated with SNPs in the IL28B locus, which encodes the antiviral cytokine interferon lambda. The rs8099917 minor allele was associated with progression to chronic HCV infection (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.74-3.06; P = 6.07 x 10(-9)). The association was observed in HCV mono-infected (OR, 2.49; 95% CI, 1.64-3.79; P = 1.96 x 10(-5)) and HCV/HIV coinfected individuals (OR, 2.16; 95% CI, 1.47-3.18; P = 8.24 x 10(-5)). rs8099917 was also associated with failure to respond to therapy (OR, 5.19; 95% CI, 2.90-9.30; P = 3.11 x 10(-8)), with the strongest effects in patients with HCV genotype 1 or 4. This risk allele was identified in 24% of individuals with spontaneous HCV clearance, 32% of chronically infected patients who responded to therapy, and 58% who did not respond (P = 3.2 x 10(-10)). Resequencing of IL28B identified distinct haplotypes that were associated with the clinical phenotype. CONCLUSIONS: The association of the IL28B locus with natural and treatment-associated control of HCV indicates the importance of innate immunity and interferon lambda in the pathogenesis of HCV infection.
Resumo:
To assess the impact of international consensus conference guidelines on the attitude of Swiss specialists when facing the decision to treat chronic hepatitis C patients. Questionnaires focusing on the personal situation and treatment decisions were mailed to 165 patients who were newly diagnosed with hepatitis C virus (HCV) infection and enrolled into the Swiss Hepatitis C Cohort Study during the years 2002-2004. Survey respondents (n = 86, 52.1%) were comparable to non-respondents with respect to severity of liver disease, history of substance abuse and psychiatric co-morbidities. Seventy percent of survey respondents reported having been offered antiviral treatment. Patients deferred from treatment had less advanced liver fibrosis, were more frequently infected with HCV genotypes 1 or 4 and presented more often with a history of depression. There were no differences regarding age, socio-economic background, alcohol abuse, intravenous drug abuse or methadone treatment when compared with patients to whom treatment was proposed. Ninety percent of eligible patients agreed to undergo treatment. Overall, 54.6% of respondents and 78.3% of those considered eligible had actually received antiviral therapy by 2007. Ninety-five percent of patients reported high satisfaction with their own hepatitis C management. Consistent with latest international consensus guidelines, patients enrolled in the Swiss Hepatitis C Cohort with a history of substance abuse were not withheld antiviral treatment. A multidisciplinary approach is warranted to provide antiviral treatment to patients suffering from depression.
Resumo:
The identification of associations between interleukin-28B (IL-28B) variants and the spontaneous clearance of hepatitis C virus (HCV) raises the issues of causality and the net contribution of host genetics to the trait. To estimate more precisely the net effect of IL-28B genetic variation on HCV clearance, we optimized genotyping and compared the host contributions in multiple- and single-source cohorts to control for viral and demographic effects. The analysis included individuals with chronic or spontaneously cleared HCV infections from a multiple-source cohort (n = 389) and a single-source cohort (n = 71). We performed detailed genotyping in the coding region of IL-28B and searched for copy number variations to identify the genetic variant or haplotype carrying the strongest association with viral clearance. This analysis was used to compare the effects of IL-28B variation in the two cohorts. Haplotypes characterized by carriage of the major alleles at IL-28B single-nucleotide polymorphisms (SNPs) were highly overrepresented in individuals with spontaneous clearance versus those with chronic HCV infections (66.1% versus 38.6%, P = 6 × 10(-9) ). The odds ratios for clearance were 2.1 [95% confidence interval (CI) = 1.6-3.0] and 3.9 (95% CI = 1.5-10.2) in the multiple- and single-source cohorts, respectively. Protective haplotypes were in perfect linkage (r(2) = 1.0) with a nonsynonymous coding variant (rs8103142). Copy number variants were not detected. We identified IL-28B haplotypes highly predictive of spontaneous HCV clearance. The high linkage disequilibrium between IL-28B SNPs indicates that association studies need to be complemented by functional experiments to identify single causal variants. The point estimate for the genetic effect was higher in the single-source cohort, which was used to effectively control for viral diversity, sex, and coinfections and, therefore, offered a precise estimate of the net host genetic contribution.