To assess, at ART initiation, the impact of baseline substitutions in protease, Gag and gp41 regions on the virological response to a first-line PI-based regimen.
One hundred and fifty-four ...HIV-infected ART-naive patients initiating a PI-based regimen including darunavir (n = 129) or atazanavir (n = 25) were assessed, including 36 experiencing virological failure (VF). Whole pol, gag and gp41 genes were sequenced at ART baseline by ultra-deep sequencing (UDS) using Illumina® technology. Supervised data-mining analyses were performed to identify mutations associated with virological response. Structural analyses were performed to assess the impact of mutations on protease conformation.
UDS was successful in 127, 138 and 134 samples for protease, Gag and gp41, respectively (31% subtype B and 38% CRF02_AG). Overall, T4A and S37T mutations in protease were identified as being associated with VF (P = 0.02 and P = 0.005, respectively). Among CRF02_AG sequences, I72M and E21D mutations were associated with VF (P = 0.03 for both). They all induced some conformational changes of some protease side-chain residues located near mutated residues. In Gag, mutations associated with VF were G62D, N315H and Y441S (P = 0.005, P = 0.007 and P = 0.0003, respectively). All were localized outside Gag cleavage sites (G62D, matrix; N315H, capsid; and Y441S, p1). In gp41, the I270T mutation, localized in the cytoplasmic tail, was associated with VF (P = 0.003), and the I4L mutation, in the fusion peptide, was associated with virological success (P = 0.004).
In this study, new baseline substitutions in Gag, protease and g41, potentially impacting PI-based regimen outcome, were evidenced. Phenotypic analyses are required to confirm their role in the PI-resistance mechanism.
•Cobas 6800 results correlated well with those of Cobas TaqMan for HIV, HBV and HCV.•However, Cobas 6800 tended to yield higher viremia for HIV and lower for HBV.•For HCV, Cobas 6800 gave lower or ...higher values depending on the area of the range.•Discrepancies are observed between Cobas 6800 and Abbott Realtime for HCV.
The new Roche Cobas 6800 platform (C6800) has been recently introduced for viral load (VL) measurement.
Comparing C6800 to Cobas Ampliprep/Cobas TaqMan v2.0 (CAP/CTM) for the quantification of HIV, HBV and HCV viremia, and to the Abbott RealTime assay (ABB) for HCV quantification.
We analysed 121 samples for HBV, and 139 for HIV-1 including 2 groupO and 137 group M viruses (36.5% subtype B, 27.0% CRF02_AG, 22.6% from other clades, and 14% subtype not available). For the 100 HCV samples compared with CAP/CTM, 42% were genotype 1 and 17% were genotype 4. For the 68 HCV samples compared with ABB, 52.9% were genotype 1 and 22.1% were genotype 4.
C6800 results correlated well with those of CAP/CTM for all three viruses (R2: 0.97–0.99). However, C6800 can yield different viraemia results: higher for HIV (mean difference: +0.11 log10copies/mL, p<0.0001), and lower for HBV (mean difference:-0.11 log10 IU/mL, p<0.0001). Differences exceeded 0.5 log10 for 6.5% of HIV-1 samples and 7.4% of HBV samples. For HCV quantification, C6800 gave mostly lower values than the other assays towards the bottom of the range, and higher values in the upper part of the range, especially in comparisons with ABB, for which 28% of differences exceeded 0.5 log10 IU/mL. No particular HCV genotype was identified as responsible for these differences.
Overall, the comparison tests between C6800 and CAP/CTM systems are satisfactory for the three viruses. Frequent discrepancies were observed between C6800 and ABB for HCV.
To evaluate, in a clinical cohort of HIV-1-infected patients, the prevalence of PI minority resistant variants (MRV) at ART baseline and their impact on the virological response to a first-line ...PI-based regimen.
In an observational single-centre cohort, we assessed all ART-naive patients initiating a first-line regimen including two NRTI and one boosted PI, darunavir/ritonavir or atazanavir/ritonavir, between January 2012 and March 2015. Ultra-deep sequencing of the pol gene was performed using Illumina® technology. Protease mutations were identified using the WHO transmitted drug resistance list and major PI resistance mutations (IAS-USA drug resistance mutations list).
Ninety-four and 16 patients initiating a darunavir/ritonavir-based regimen and an atazanavir/ritonavir-based regimen, respectively, were assessed. Twenty-eight percent of the patients were HIV-1 subtype B, 39% CRF02_AG and 33% other non-B subtypes. Thirteen patients (13.8%) in the darunavir group and three patients (18.8%) in the atazanavir group experienced a virological failure (VF). Overall, 13 (11.8%) subjects had PI MRV at baseline in the median proportion of 1.3% (IQR = 1.1-1.7). The most prevalent PI MRV were G73C (n = 5) and M46I (n = 3). The proportion of patients harbouring baseline PI MRV was similar between those with virological success (10.6%) and those experiencing VF (18.8%) (P = 0.40). No difference was observed in the rate of PI MRV by viral subtype (P = 0.51) or by PI drug (P = 0.40).
This study showed a prevalence of 11.8% of PI MRV among 110 ART-naive subjects, without significant impact on the virological response to a first-line PI-based regimen containing darunavir or atazanavir.
Hepatitis E virus (HEV) can induce chronic infections in the case of immunosuppression, which are sometimes not cured with ribavirin. Furthermore, sofosbuvir is a highly potent inhibitor of HCV ...polymerase and was shown to inhibit HEV genotype-3 replication in vitro. We report here the outcome of sofosbuvir/ribavirin therapy on a chronic HEV infection in a heart transplant recipient non-responder to ribavirin. After 24 weeks, the regimen failed to cure the persistent HEV infection, highlighting the need of therapeutic options for HEV-infected immunosuppressed patients.
OBJECTIVE:Several studies reported hepatitis C virus (HCV) transmission networks among men having sex with men (MSM) in Europe and the spread of HCV strains from HIV–HCV coinfected toward HCV ...monoinfected MSM. We aimed to investigate HCV transmission dynamics among HIV-positive and HIV-negative MSM by ultradeep sequencing (UDS).
DESIGN AND METHODS:NS5B fragment (388 bp) was sequenced from virus of 50 HIV-positive and 18 HIV-negative patients diagnosed with recent HCV infection. UDS data were analyzed by Geneious (version 10.3.2). Phylogenetic trees were constructed by FastTree (version 2.1) and submitted to ClusterPicker (version 1.2.3) for transmission chain detection at different thresholds of maximum genetic distance (MGD) (3% for Sanger, 3% and 4.5% for UDS).
RESULTS:Ten, 17, and 18 HCV transmission chains were identified by Sanger at 3%, UDS at 3% and at 4.5% of MGD, respectively. Of 68 subjects enrolled, 38 (55.9%), 38 (55.9%), and 43 (65.3%) individuals were involved in transmission networks found by Sanger at 3%, UDS at 3%, and at 4.5% of MGD, respectively. Mixed transmission chains including HIV-positive and HIV-negative subjects were detected for 8/10 chains by Sanger at 3%, for 9/17 by UDS at 3%, and for 10/18 by UDS at 4.5% of MGD. Overall, the number of HIV-negative individuals clustering with HIV-positive ones was 9/18 by Sanger, 9/18 by UDS at 3%, and 10/18 by UDS at 4.5% of MGD.
CONCLUSIONS:HIV-positive and HIV-negative MSM shared HCV transmission networks, which emphasizes the need for HCV surveillance and prevention measures in these communities regardless of the HIV status.
•Patients infected by difficult-to-treat HCV genotype 3 and 4 viruses were studied.•Resistance-associated substitutions were concurrently detected by Sanger sequencing and NGS.•Substitution at ...position 28 of NS5A protein emerged in a genotype 4 virus.•Emergence of new substitutions in NS5B prompts further research by mutagenesis.
More data on resistance of HCV genotype (GT) 3 and 4 to direct-acting antivirals (DAAs) are still needed. Here we investigated the presence of resistance-associated substitutions (RASs) pre- and post-treatment and their emergence under DAAs in HCV GT3- and GT4-infected patients failing DAA regimens by next-generation sequencing (NGS). Sanger sequencing and NGS were performed on NS5B and NS5A in plasma samples prior to and post treatment of 13 patients. Positions implicated in resistance to anti-NS5A and anti-NS5B in the literature were analysed. No baseline RASs was detected in NS5B but one GT4r virus developed the mutation S282T at failure. In NS5A, pre-existing RASs or polymorphisms were detected in viruses of 6/10 patients (L28M for a GT4a, M28V for a GT4r, L30R for a GT4a, 2 GT4d and 1 GT4r, and T58P for a GT4d) by Sanger sequencing and in viruses of 7/10 patients by NGS. Additional baseline minority substitutions detected by NGS were Y93H in a GT3a, L28M in a GT4a and GT4d, and L28F in a GT4d virus. At failure, these substitutions were found at a frequency of 100%. Y93H was detected alone at baseline, whilst L28M and L28F were accompanied by polymorphisms L30R or L30R + T58P. Use of NGS in patients failing DAAs and infected by HCV GT3 and GT4 revealed the emergence of specific patterns of substitutions in NS5A and NS5B, in particular substitutions at position 28 in NS5A in GT4 virus, highlighting the need to list these substitutions in guidelines for resistance interpretation.
Abstract
Objectives
To further characterize HIV-1 viruses of patients experiencing unexplained virological failure (VF) on PI-containing regimens, ultradeep sequencing was performed on protease, gag ...and gp41 genes in patients failing a first-line treatment.
Methods
All naive patients initiating an antiretroviral treatment based on boosted darunavir, atazanavir or lopinavir and experiencing VF without any transmitted drug resistance mutation detected by Sanger sequencing on protease and reverse transcriptase genes were selected. Ultradeep sequencing (IlluminaTM Nextera®) was performed on protease, gag and gp41 genes in plasma before initiation of treatment and at VF to identify emergent mutations.
Results
Among the 32 patients included in the study, emergent and previously undescribed mutations in the viral protease gene were identified in five patients at VF: 64M (1 CRF02_AG), 64M/70R with mutation 15V (2 CRF02_AG), 79A (1 CRF06_cpx) and 79A with mutation 15V (1 CRF02_AG). Two patients showed the emergence of R286K in the gag region, outside of cleavage sites (2 CRF02_AG). In the gp41 region, the V321I mutation emerged inside the cytoplasmic tail (1 subtype A and 1 subtype B). All these patients were treated with a darunavir/ritonavir-based regimen.
Conclusions
In some cases of VF to PIs, we observed the emergence of protease, Gag or Gp41 mutations that had not previously been associated with VF or PI resistance. These mutations should be further studied, in particular the 15V/64M/70R pattern in the protease gene identified among CRF02_AG viruses.
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