158 research outputs found
Hepatitis C virus transmission between eight high-income countries among men who have sex with men: a whole-genome analysis.
BACKGROUND
Microelimination of the hepatitis C virus (HCV) among men who have sex with men (MSM) could be complicated by continuous external introductions and the emergence of phylogenetic clusters harbouring clinically significant resistance-associated substitutions (RAS). To investigate international clustering and the prevalence and transmission of RAS, we aimed to analyse whole-genome HCV sequences from MSM with a recently acquired infection who participated in a large, international HCV treatment trial.
METHODS
For this whole-genome analysis, we obtained HCV sequences from 128 MSM who had acquired HCV within the past 12 months and were participating in the REACT trial. The participants from whom sequences were obtained were recruited at 24 sites in eight countries. We inferred maximum-likelihood phylogenies and identified transmission clusters for HCV genotypes separately. We constructed time-scaled phylogenies to estimate cluster introduction dates and used a Bayesian Skygrid approach to estimate the effective population size over the past 50 years. We calculated the prevalence of RAS and the extent of RAS transmission in the study population.
FINDINGS
The majority of recent HCV infections were part of international networks that arose in the late 1990s and early 2000s. Sequences obtained in the same country clustered frequently, and in 36% of subclusters since 2015 we found evidence of international transmission. European MSM were more likely than non-European MSM to be in a cluster (odds ratio 11·9 [95% CI 3·6-43·4], p<0·0001). The effective population size decreased rapidly since around 2015 in Europe. RAS associated with substantially diminished cure rates were infrequently detected and transmission of highly resistant viruses was not observed.
INTERPRETATION
Despite antiviral treatment becoming widely available, international transmission of HCV among MSM has still occurred over the past 8 years, which could complicate microelimination of the virus in this population. RAS-enriched clusters and widespread RAS transmission are currently not a threat to elimination goals. These findings support an international approach for HCV microelimination among MSM.
FUNDING
National Institutes of Health and Dr. C.J. Vaillant Fonds
AR-quiver approach to affine canonical basis elements
AbstractThis is the continuation of [Y. Li, Affine quivers of type AËn and canonical bases, math.QA/0501175]. We describe the affine canonical basis elements in the case when the affine quiver has arbitrary orientation. This generalizes the description in [G. Lusztig, Affine quivers and canonical bases, Publ. Math. Inst. Hautes Ătudes Sci. 76 (1992) 111â163]
Sofosbuvir/velpatasvir for 12 vs. 6 weeks for the treatment of recently acquired hepatitis C infection.
BACKGROUND AND AIMS
Shortened duration therapy for acute and recent hepatitis C virus (HCV) infection has been shown to be highly effective in several small non-randomised studies with direct-acting antiviral regimens, however large randomised studies are lacking.
METHODS
REACT was an NIH-funded multicentre international, open-label, randomised, phase 4 non-inferiority trial examining the efficacy of short course (6 weeks) versus standard course (12 weeks) therapy with sofosbuvir-velpatasvir for recent HCV infection (estimated duration of infection <= 12 months). Randomisation occurred at week 6. The primary endpoint was SVR12 in the intention-to treat (ITT) population. A total of 250 participants were planned for enrolment. On advice of the data safety and monitoring board the study was halted early.
RESULTS
Primary analysis population consisted of 188 randomised participants at termination of study enrolment; short arm (n=93), standard arm (n=95). Ninety seven percent were male and 69% HIV positive. ITT SVR12 was 76/93, 81.7% (95% CI 72.4-89.0) in the short arm and 86/95, 90.5% (95% CI 82.7-95.6) in the standard arm. The difference between the arms was -8.8 (95% CI: -18.6, 1.0). By modified ITT analysis in which non-virological reasons for failure were excluded (death, reinfection, lost to follow-up) SVR12 was 76/85, 89.4% (95% CI 80.8-95.0) in the short arm and 86/88, 97.7% in the standard arm (95% CI 92.0-99.7; difference -8.3%, p=0.025).
CONCLUSIONS
In this randomised study in recent HCV infection, 6 weeks sofosbuvir-velpatasvir did not meet the criteria for non-inferiority to standard 12 weeks duration.
LAY SUMMARY
In this randomised trial one hundred and eighty people with recently acquired hepatitis C infection were randomly assigned to treatment using either a short 6-week course (93 people) or standard 12-week course (95 people) of the hepatitis C treatment sofosbuvir/velpatasvir. There were nine cases of relapse after treatment in the short course and two using the standard course. A shortened course of 6 weeks therapy for hepatitis C infection was considered not as effective as a standard twelve week course in people with recently acquired hepatitis C infection.
TRIAL REGISTRATION
Clinicaltrials.gov Identifier: NCT02625909
Sequencing of the Hepatitis C Virus: A Systematic Review
Since the identification of hepatitis C virus (HCV), viral sequencing has been important in understanding HCV classification, epidemiology, evolution, transmission clustering, treatment response and natural history. The length and diversity of the HCV genome has resulted in analysis of certain regions of the virus, however there has been little standardisation of protocols. This systematic review was undertaken to map the location and frequency of sequencing on the HCV genome in peer reviewed publications, with the aim to produce a database of sequencing primers and amplicons to inform future research. Medline and Scopus databases were searched for English language publications based on keyword/MeSH terms related to sequence analysis (9 terms) or HCV (3 terms), plus "primer" as a general search term. Exclusion criteria included non-HCV research, review articles, duplicate records, and incomplete description of HCV sequencing methods. The PCR primer locations of accepted publications were noted, and purpose of sequencing was determined. A total of 450 studies were accepted from the 2099 identified, with 629 HCV sequencing amplicons identified and mapped on the HCV genome. The most commonly sequenced region was the HVR-1 region, often utilised for studies of natural history, clustering/transmission, evolution and treatment response. Studies related to genotyping/classification or epidemiology of HCV genotype generally targeted the 5'UTR, Core and NS5B regions, while treatment response/resistance was assessed mainly in the NS3-NS5B region with emphasis on the Interferon sensitivity determining region (ISDR) region of NS5A. While the sequencing of HCV is generally constricted to certain regions of the HCV genome there is little consistency in the positioning of sequencing primers, with the exception of a few highly referenced manuscripts. This study demonstrates the heterogeneity of HCV sequencing, providing a comprehensive database of previously published primer sets to be utilised in future sequencing studies
The close classical T Tauri binary V4046 Sgr: Complex magnetic fields & distributed mass accretion
We report here the first results of a multi-wavelength campaign focussing on
magnetospheric accretion processes within the close binary system V4046 Sgr,
hosting two partly-convective classical T Tauri stars of masses ~0.9 Msun and
age ~12 Myr. In this paper, we present time-resolved spectropolarimetric
observations collected in 2009 September with ESPaDOnS at the
Canada-France-Hawaii Telescope (CFHT) and covering a full span of 7d or ~2.5
orbital/rotational cycles of V4046 Sgr. Small circularly polarised Zeeman
signatures are detected in the photospheric absorption lines but not in the
accretion-powered emission lines of V4046 Sgr, thereby demonstrating that both
system components host large-scale magnetic fields weaker and more complex than
those of younger, fully-convective cTTSs of only a few Myr and similar masses.
Applying our tomographic imaging tools to the collected data set, we
reconstruct maps of the large-scale magnetic field, photospheric brightness and
accretion-powered emission at the surfaces of both stars of V4046 Sgr. We find
that these fields include significant toroidal components, and that their
poloidal components are mostly non-axisymmetric with a dipolar component of
50-100G strongly tilted with respect to the rotation axis; given the similarity
with fields of partly-convective main-sequence stars of similar masses and
rotation periods, we conclude that these fields are most likely generated by
dynamo processes. We also find that both stars in the system show cool spots
close to the pole and extended regions of low-contrast, accretion-powered
emission; it suggests that mass accretion is likely distributed rather than
confined in well defined high-contrast accretion spots, in agreement with the
derived magnetic field complexity.Comment: MNRAS in press (13 pages, 7 figures
Adherence to sofosbuvir and velpatasvir among people with chronic HCV infection and recent injection drug use:The SIMPLIFY study
BACKGROUND:This study investigated treatment adherence among people with recent injecting drug use in a study of sofosbuvir/velpatasvir therapy for HCV infection. METHODS:SIMPLIFY is an international open-label, single-arm multicentre study that recruited participants with recent injecting drug use (previous six months) and chronic HCV genotype (G) 1-6 infection between March and October 2016 in seven countries (19 sites). Participants received sofosbuvir/velpatasvir once-daily for 12 weeks administered in a one-week electronic blister pack (records the time and date of each dose) for 12 weeks. We evaluated non-adherence (<90% adherent) as measured by electronic blister-pack assessed using logistic regression and generalised estimating equations (continuous) with detailed analyses of dosing dynamics. RESULTS:Among 103 participants, 97% (nâ=â100) completed treatment. Median adherence to therapy was 94%. Overall, 32% (nâ=â33) were considered non-adherent (<90% adherence). Adherence significantly decreased over the course of therapy. Recent stimulant injecting (cocaine and/or amphetamines) at treatment initiation and during treatment was independently associated with non-adherence. Inconsistent dose timing (standard deviation of daily dose timing of â„240âmin) was also independently associated with non-adherence to therapy. Factors associated with inconsistent dose timing included lower levels of education and recent stimulant injecting. SVR was similar among adherent and non-adherent populations (94% vs. 94%, Pâ=â0.944). CONCLUSION:This study demonstrated high adherence to once-daily sofosbuvir/velpatasvir therapy among a population of people with recent injecting drug use. Recent stimulant injecting prior to and during DAA therapy and inconsistent dose-timing during treatment was associated with non-adherence. However, there was no impact of non-adherence on response to therapy, suggesting that adherence is not a significant barrier to successful DAA therapy in people with recent injecting drug use.Evan B.Cunningham, Janaki Amin, Jordan J.Feld, Julie Bruneau, Olav Dalgard, Jeff Powis ... et al
MBOAT7 rs641738 increases risk of liver inflammation and transition to fibrosis in chronic hepatitis C
Cirrhosis likely shares common pathophysiological pathways despite arising from a variety of liver diseases. A recent GWAS identified rs641738, a polymorphism in the MBOAT7 locus, as being associated with the development of alcoholic cirrhosis. Here we explore the role of this variant on liver inflammation and fibrosis in two cohorts of patients with chronic hepatitis C. In 2,051 patients, rs641738 associated with severe hepatic inflammation and increased risk of fibrosis, as well as fast fibrosis progression. At functional level, rs641738 associated with MBOAT7 transcript and protein levels in liver and blood, and with serum inflammatory, oxidative stress and macrophage activation markers. MBOAT7 was expressed in immune cell subsets, implying a role in hepatic inflammation. We conclude that the MBOAT7 rs641738 polymorphism is a novel risk variant for liver inflammation in hepatitis C, and thereby for liver fibrosis
Interferon-λ rs12979860 genotype and liver fibrosis in viral and non-viral chronic liver disease
IFN-λ3, not IFN-λ4, likely mediates IFNL3âIFNL4 haplotypeâdependent hepatic inflammation and fibrosis
The International Liver Disease Genetics Consortium (ILDGC).Genetic variation in the IFNL3âIFNL4 (interferon-λ3âinterferon-λ4) region is associated with hepatic inflammation and fibrosis1,2,3,4. Whether IFN-λ3 or IFN-λ4 protein drives this association is not known. We demonstrate that hepatic inflammation, fibrosis stage, fibrosis progression rate, hepatic infiltration of immune cells, IFN-λ3 expression, and serum sCD163 levels (a marker of activated macrophages) are greater in individuals with the IFNL3âIFNL4 risk haplotype that does not produce IFN-λ4, but produces IFN-λ3. No difference in these features was observed according to genotype at rs117648444, which encodes a substitution at position 70 of the IFN-λ4 protein and reduces IFN-λ4 activity, or between patients encoding functionally defective IFN-λ4 (IFN-λ4âSer70) and those encoding fully active IFN-λ4âPro70. The two proposed functional variants (rs368234815 and rs4803217)5,6 were not superior to the discovery SNP rs12979860 with respect to liver inflammation or fibrosis phenotype. IFN-λ3 rather than IFN-λ4 likely mediates IFNL3âIFNL4 haplotypeâdependent hepatic inflammation and fibrosis.M.E., M.D., and J.G. are supported by the Robert W. Storr Bequest to the Sydney Medical Foundation, University of Sydney, and by a National Health and Medical Research Council of Australia (NHMRC) Program Grant (1053206) and NHMRC Project Grants (APP1107178 and APP1108422). G.D. is supported by an NHMRC Fellowship (1028432)
The QT interval and risk of incident atrial fibrillation
Abnormal atrial repolarization is important in the development of atrial fibrillation (AF), but no direct measurement is available in clinical medicine
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