Resistance test guided retreatment of HCV infected patients with a previous failure to a NS5A inhibitor-containing regimen: the Italian Vironet C rea…

2019

Previous article in issueNext article in issue Introduction: There is a limited documentation about the retreatment of patients failing a recommended NS5A-containing regimen in Italy. Materials & methods: Within the VIRONET-C network, 386 NS5A-failing patients infected with different HCV-genotypes (GT) (GT1a/1b/2a-c/3a-b-g-h/4a-d-n-o-v=93/124/19/112/38) were analyzed. Retreatment of 105 failures was investigated. HCV-resistance-test was performed by Sanger-sequencing. Results: Failures following seven different NS5A-containing regimens were studied: 3D/2D (paritaprevir/ombitasvir ± dasabuvir) ± ribavirin (N = 72/4), daclatasvir/ledipasvir/velpatasvir + sofosbuvir ± ribavirin (N = 105/13…

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

2016

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Failure on voxilaprevir, velpatasvir, sofosbuvir and efficacy of rescue therapy

2021

Background & Aims There are limited data on patients with chronic HCV infection in whom combination voxilaprevir (VOX), velpatasvir (VEL), sofosbuvir (SOF) retreatment fails. Thus, we aimed to assess treatment failure and rescue treatment options in these patients. Methods Samples from 40 patients with HCV genotypes (GT) 1-4 in whom VOX/VEL/SOF retreatment failed were collected within the European Resistance Study Group. Population-based resistance analyses were conducted and clinical parameters and retreatment efficacies were evaluated retrospectively in 22 patients. Results Most VOX/VEL/SOF failure patients were infected with HCV GT3a (n = 18, 45%) or GT1a (n = 11, 28%) and had cirrhosis …

Evaluation of HIV-1 integrase resistance emergence and evolution in patients treated with integrase inhibitors

2020

Abstract Objectives This study evaluated the emergence of mutations associated with integrase strand transfer inhibitors (INSTI) resistance (INSTI-RMs) and the integrase evolution in human immunodeficiency virus type 1 (HIV-1) infected patients treated with this drug class. Methods The emergence of INSTI-RMs and integrase evolution (estimated as genetic distance between integrase sequences under INSTI treatment and before INSTI treatment) were evaluated in 107 INSTI-naive patients (19 drug-naive and 88 drug-experienced) with two plasma genotypic resistance tests: one before INSTI treatment and one under INSTI treatment. A logistic regression analysis was performed to evaluate factors associ…

Frequent NS5A and multiclass resistance in almost all HCV genotypes at DAA failures: What are the chances for second-line regimens?

2017

Prevalence of Single and Multiple Natural NS3, NS5A and NS5B Resistance-Associated Substitutions in Hepatitis C Virus Genotypes 1-4 in Italy

2018

AbstractNatural resistance-associated substitutions (RASs) are reported with highly variable prevalence across different HCV genotypes (GTs). Frequency of natural RASs in a large Italian real-life cohort of patients infected with the 4 main HCV-GTs was investigated. NS3, NS5A and NS5B sequences were analysed in 1445 HCV-infected DAA-naïve patients. Sanger-sequencing was performed by home-made protocols on 464 GT1a, 585 GT1b, 92 GT2c, 199 GT3a, 16 GT4a and 99 GT4d samples. Overall, 20.7% (301/1455) of patients showed natural RASs, and the prevalence of multiclass-resistance was 7.3% (29/372 patients analysed). NS3-RASs were particularly common in GT1a and GT1b (45.2-10.8%, respectively), mai…

A novel methodology for large-scale phylogeny partition

2011

Understanding the determinants of virus transmission is a fundamental step for effective design of screening and intervention strategies to control viral epidemics. Phylogenetic analysis can be a valid approach for the identification of transmission chains, and very-large data sets can be analysed through parallel computation. Here we propose and validate a new methodology for the partition of large-scale phylogenies and the inference of transmission clusters. This approach, on the basis of a depth-first search algorithm, conjugates the evaluation of node reliability, tree topology and patristic distance analysis. The method has been applied to identify transmission clusters of a phylogeny …