1
|
Blanch-Lombarte O, Santos JR, Peña R, Jiménez-Moyano E, Clotet B, Paredes R, Prado JG. HIV-1 Gag mutations alone are sufficient to reduce darunavir susceptibility during virological failure to boosted PI therapy. J Antimicrob Chemother 2020; 75:2535-2546. [PMID: 32556165 PMCID: PMC7443716 DOI: 10.1093/jac/dkaa228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/21/2020] [Accepted: 05/03/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Virological failure (VF) to boosted PIs with a high genetic barrier is not usually linked to the development of resistance-associated mutations in the protease gene. METHODS From a cohort of 520 HIV-infected subjects treated with lopinavir/ritonavir or darunavir/ritonavir monotherapy, we retrospectively identified nine patients with VF. We sequenced the HIV-1 Gag-protease region and generated clonal virus from plasma samples. We characterized phenotypically clonal variants in terms of replicative capacity and susceptibility to PIs. Also, we used VESPA to identify signature mutations and 3D molecular modelling information to detect conformational changes in the Gag region. RESULTS All subjects analysed harboured Gag-associated polymorphisms in the absence of resistance mutations in the protease gene. Most Gag changes occurred outside Gag cleavage sites. VESPA analyses identified K95R and R286K (P < 0.01) as signature mutations in Gag present at VF. In one out of four patients with clonal analysis available, we identified clonal variants with high replicative capacity and 8- to 13-fold reduction in darunavir susceptibility. These clonal variants harboured K95R, R286K and additional mutations in Gag. Low susceptibility to darunavir was dependent on the Gag sequence context. All other clonal variants analysed preserved drug susceptibility and virus replicative capacity. CONCLUSIONS Gag mutations may reduce darunavir susceptibility in the absence of protease mutations while preserving viral fitness. This effect is Gag-sequence context dependent and may occur during boosted PI failure.
Collapse
Affiliation(s)
- Oscar Blanch-Lombarte
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain and Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - José R Santos
- Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
- Infectious Diseases Department, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Ruth Peña
- IrsiCaixa AIDS Research Institute, Badalona, Spain
| | | | - Bonaventura Clotet
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Roger Paredes
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Julia G Prado
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain and Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| |
Collapse
|
2
|
Datir R, El Bouzidi K, Dakum P, Ndembi N, Gupta RK. Baseline PI susceptibility by HIV-1 Gag-protease phenotyping and subsequent virological suppression with PI-based second-line ART in Nigeria. J Antimicrob Chemother 2020; 74:1402-1407. [PMID: 30726945 PMCID: PMC6477990 DOI: 10.1093/jac/dkz005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/14/2018] [Accepted: 12/31/2018] [Indexed: 12/24/2022] Open
Abstract
Objectives Previous work showed that gag-protease-derived phenotypic susceptibility to PIs differed between HIV-1 subtype CRF02_AG/subtype G-infected patients who went on to successfully suppress viral replication versus those who experienced virological failure of lopinavir/ritonavir monotherapy as first-line treatment in a clinical trial. We analysed the relationship between PI susceptibility and outcome of second-line ART in Nigeria, where subtypes CRF02_AG/G dominate the epidemic. Methods Individuals who experienced second-line failure with ritonavir-boosted PI-based ART were matched (by subtype, sex, age, viral load, duration of treatment and baseline CD4 count) to those who achieved virological response (‘successes’). Successes were defined by viral load <400 copies of HIV-1 RNA/mL by week 48. Full-length Gag-protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with PI susceptibility expressed as IC50 fold change (FC) relative to a subtype B reference strain. Results The median (IQR) lopinavir IC50 FC was 4.04 (2.49–7.89) for virological failures and 4.13 (3.14–8.17) for virological successes (P = 0.94). One patient had an FC >10 for lopinavir at baseline and experienced subsequent virological failure with ritonavir-boosted lopinavir as the PI. There was no statistically significant difference in single-round replication efficiency between the two groups (P = 0.93). There was a moderate correlation between single-round replication efficiency and FC for lopinavir (correlation coefficient 0.32). Conclusions We found no impact of baseline HIV-1 Gag-protease-derived phenotypic susceptibility on outcomes of PI-based second-line ART in Nigeria.
Collapse
Affiliation(s)
- R Datir
- Division of Infection and Immunity, University College London, London, UK
| | - K El Bouzidi
- Division of Infection and Immunity, University College London, London, UK
| | - P Dakum
- Institute of Human Virology, Abuja, Nigeria
| | - N Ndembi
- Institute of Human Virology, Abuja, Nigeria
| | - R K Gupta
- Division of Infection and Immunity, University College London, London, UK.,Africa Health Research Institute, Durban, South Africa
| |
Collapse
|
3
|
Tzou PL, Rhee SY, Pond SLK, Manasa J, Shafer RW. Selection analyses of paired HIV-1 gag and gp41 sequences obtained before and after antiretroviral therapy. Sci Data 2018; 5:180147. [PMID: 30040081 PMCID: PMC6057438 DOI: 10.1038/sdata.2018.147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 05/29/2018] [Indexed: 11/08/2022] Open
Abstract
Most HIV-1-infected individuals with virological failure on a pharmacologically-boosted protease inhibitor (PI) regimen do not develop PI-resistance protease mutations. One proposed explanation is that HIV-1 gag or gp41 cytoplasmic domain mutations might also reduce PI susceptibility. In a recent study of paired gag and gp41 sequences from individuals with virological failure on a PI regimen, we did not identify PI-selected mutations and concluded that if such mutations existed, larger numbers of paired sequences from multiple studies would be needed for their identification. In this study, we generated site-specific amino acid profiles using gag and gp41 published sequences from 5,338 and 4,242 ART-naïve individuals, respectively, to assist researchers identify unusual mutations arising during therapy and to provide scripts for performing established and novel maximal likelihood estimates of dN/dS substitution rates in paired sequences. The pipelines used to generate the curated sequences, amino acid profiles, and dN/dS analyses will facilitate the application of consistent methods to paired gag and gp41 sequence datasets and expedite the identification of potential sites under PI-selection pressure.
Collapse
Affiliation(s)
- Philip L. Tzou
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA 94305, USA
| | - Soo-Yon Rhee
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA 94305, USA
| | | | - Justen Manasa
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA 94305, USA
| | - Robert W. Shafer
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
4
|
Manasa J, Varghese V, Pond SLK, Rhee SY, Tzou PL, Fessel WJ, Jang KS, White E, Rögnvaldsson T, Katzenstein DA, Shafer RW. Evolution of gag and gp41 in Patients Receiving Ritonavir-Boosted Protease Inhibitors. Sci Rep 2017; 7:11559. [PMID: 28912582 PMCID: PMC5599673 DOI: 10.1038/s41598-017-11893-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 08/31/2017] [Indexed: 11/15/2022] Open
Abstract
Several groups have proposed that genotypic determinants in gag and the gp41 cytoplasmic domain (gp41-CD) reduce protease inhibitor (PI) susceptibility without PI-resistance mutations in protease. However, no gag and gp41-CD mutations definitively responsible for reduced PI susceptibility have been identified in individuals with virological failure (VF) while receiving a boosted PI (PI/r)-containing regimen. To identify gag and gp41 mutations under selective PI pressure, we sequenced gag and/or gp41 in 61 individuals with VF on a PI/r (n = 40) or NNRTI (n = 20) containing regimen. We quantified nonsynonymous and synonymous changes in both genes and identified sites exhibiting signal for directional or diversifying selection. We also used published gag and gp41 polymorphism data to highlight mutations displaying a high selection index, defined as changing from a conserved to an uncommon amino acid. Many amino acid mutations developed in gag and in gp41-CD in both the PI- and NNRTI-treated groups. However, in neither gene, were there discernable differences between the two groups in overall numbers of mutations, mutations displaying evidence of diversifying or directional selection, or mutations with a high selection index. If gag and/or gp41 encode PI-resistance mutations, they may not be confined to consistent mutations at a few sites.
Collapse
Affiliation(s)
- Justen Manasa
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | - Vici Varghese
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | | | - Soo-Yon Rhee
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | - Philip L Tzou
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | - W Jeffrey Fessel
- Department of Internal Medicine, Kaiser Permanente Medical Care Program - Northern California, San Francisco, CA, United States
| | - Karen S Jang
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | - Elizabeth White
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | | | - David A Katzenstein
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA
| | - Robert W Shafer
- Division of Infectious Diseases, Department of Medicine Stanford University, Stanford, CA, USA.
| |
Collapse
|
5
|
Saladini F, Giannini A, Boccuto A, Vicenti I, Zazzi M. Agreement between an in-house replication competent and a reference replication defective recombinant virus assay for measuring phenotypic resistance to HIV-1 protease, reverse transcriptase, and integrase inhibitors. J Clin Lab Anal 2017; 32. [PMID: 28303602 DOI: 10.1002/jcla.22206] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/21/2017] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Although clinical management of drug resistance is routinely based on genotypic methods, phenotypic assays remain necessary for the characterization of novel HIV-1 inhibitors, particularly against common drug-resistant variants. We describe the development and assessment of the performance of a recombinant virus assay for measuring HIV-1 susceptibility to protease (PR), reverse transcriptase (RT), and integrase (IN) inhibitors. METHODS The system is based on the creation of replication-competent chimeric viruses through homologous recombination between patient or laboratory virus-derived PCR fragments and the corresponding NL4-3 vector where the whole Gag-PR, RT-RNaseH or IN coding regions has been deleted through inverse PCR. The susceptibility to nucleoside (NRTIs) and non-nucleoside (NNRTIs) RT inhibitors and to IN inhibitors (INIs) is calculated through a single-round infection assay in TZM-bl cells, while protease inhibitor (PI) activity is determined through a first round of infection in MT-2 cells followed by infection of TZM-bl cells with MT-2 supernatants. RESULTS The assay showed excellent reproducibility and accuracy when testing PI, NRTI, NNRTI, and INI susceptibility of drug-resistant clones previously characterized through the reference pseudoparticle-based Phenosense assay. The coefficient of interassay variation in fold change (FC) resistance was 12.0%-24.3% when assaying seven drug/clones pairs in three runs. FC values calculated by the Phenosense and in-house for 20 drug/clones pairs were in good agreement, with mean±SD ratio of 1.14±0.33 and no cases differing by more than twofold. CONCLUSIONS The described phenotypic assay can be adopted to evaluate the antiviral activity of licensed and investigational HIV-1 drugs targeting any of the three HIV-1 enzymes.
Collapse
Affiliation(s)
- Francesco Saladini
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Alessia Giannini
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Adele Boccuto
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Ilaria Vicenti
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Maurizio Zazzi
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| |
Collapse
|
6
|
El Bouzidi K, White E, Mbisa JL, Sabin CA, Phillips AN, Mackie N, Pozniak AL, Tostevin A, Pillay D, Dunn DT. HIV-1 drug resistance mutations emerging on darunavir therapy in PI-naive and -experienced patients in the UK. J Antimicrob Chemother 2016; 71:3487-3494. [PMID: 27856703 PMCID: PMC5181398 DOI: 10.1093/jac/dkw343] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 07/21/2016] [Accepted: 07/25/2016] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Darunavir is considered to have a high genetic barrier to resistance. Most darunavir-associated drug resistance mutations (DRMs) have been identified through correlation of baseline genotype with virological response in clinical trials. However, there is little information on DRMs that are directly selected by darunavir in clinical settings. OBJECTIVES We examined darunavir DRMs emerging in clinical practice in the UK. PATIENTS AND METHODS Baseline and post-exposure protease genotypes were compared for individuals in the UK Collaborative HIV Cohort Study who had received darunavir; analyses were stratified for PI history. A selection analysis was used to compare the evolution of subtype B proteases in darunavir recipients and matched PI-naive controls. RESULTS Of 6918 people who had received darunavir, 386 had resistance tests pre- and post-exposure. Overall, 2.8% (11/386) of these participants developed emergent darunavir DRMs. The prevalence of baseline DRMs was 1.0% (2/198) among PI-naive participants and 13.8% (26/188) among PI-experienced participants. Emergent DRMs developed in 2.0% of the PI-naive group (4 mutations) and 3.7% of the PI-experienced group (12 mutations). Codon 77 was positively selected in the PI-naive darunavir cases, but not in the control group. CONCLUSIONS Our findings suggest that although emergent darunavir resistance is rare, it may be more common among PI-experienced patients than those who are PI-naive. Further investigation is required to explore whether codon 77 is a novel site involved in darunavir susceptibility.
Collapse
Affiliation(s)
- Kate El Bouzidi
- Research Department of Infection and Population Health, University College London, London, UK
- Research Department of Infection, Division of Infection and Immunity, University College London, London, UK
| | | | - Jean L Mbisa
- Virus Reference Department, Centre of Infections, Public Health England, London, UK
| | - Caroline A Sabin
- Research Department of Infection and Population Health, University College London, London, UK
| | - Andrew N Phillips
- Research Department of Infection and Population Health, University College London, London, UK
| | - Nicola Mackie
- Department of HIV Medicine, Imperial College Healthcare NHS Trust, London, UK
| | - Anton L Pozniak
- Department of Medicine, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK
| | | | - Deenan Pillay
- Research Department of Infection, Division of Infection and Immunity, University College London, London, UK
- Wellcome Trust Africa Centre for Health and Population Sciences, University of KwaZulu Natal, Mtubatuba, South Africa
| | | |
Collapse
|
7
|
Sutherland KA, Collier DA, Claiborne DT, Prince JL, Deymier MJ, Goldstein RA, Hunter E, Gupta RK. Wide variation in susceptibility of transmitted/founder HIV-1 subtype C Isolates to protease inhibitors and association with in vitro replication efficiency. Sci Rep 2016; 6:38153. [PMID: 27901085 PMCID: PMC5128871 DOI: 10.1038/srep38153] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/04/2016] [Indexed: 02/07/2023] Open
Abstract
The gag gene is highly polymorphic across HIV-1 subtypes and contributes to susceptibility to protease inhibitors (PI), a critical class of antiretrovirals that will be used in up to 2 million individuals as second-line therapy in sub Saharan Africa by 2020. Given subtype C represents around half of all HIV-1 infections globally, we examined PI susceptibility in subtype C viruses from treatment-naïve individuals. PI susceptibility was measured in a single round infection assay of full-length, replication competent MJ4/gag chimeric viruses, encoding the gag gene and 142 nucleotides of pro derived from viruses in 20 patients in the Zambia-Emory HIV Research Project acute infection cohort. Ten-fold variation in susceptibility to PIs atazanavir and lopinavir was observed across 20 viruses, with EC50s ranging 0.71-6.95 nM for atazanvir and 0.64-8.54 nM for lopinavir. Ten amino acid residues in Gag correlated with lopinavir EC50 (p < 0.01), of which 380 K and 389I showed modest impacts on in vitro drug susceptibility. Finally a significant relationship between drug susceptibility and replication capacity was observed for atazanavir and lopinavir but not darunavir. Our findings demonstrate large variation in susceptibility of PI-naïve subtype C viruses that appears to correlate with replication efficiency and could impact clinical outcomes.
Collapse
|
8
|
Saladini F, Vicenti I. Role of phenotypic investigation in the era of routine genotypic HIV-1 drug resistance testing. Future Virol 2016. [DOI: 10.2217/fvl-2016-0080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The emergence of drug resistance can seriously compromise HIV type-1 therapy and decrease therapeutic options. Resistance testing is highly recommended to guide treatment decisions and drug activity can be accurately predicted in the clinical setting through genotypic assays. While phenotypic systems are not suitable for monitoring drug resistance in routine laboratory practice, genotyping can misclassify unusual or complex mutational patterns, particularly with recently approved antivirals. In addition, phenotypic assays remain fundamental for characterizing candidate antiretroviral compounds. This review aims to discuss how phenotypic assays contributed to and still play a role in understanding the mechanisms of resistance of both licensed and investigational HIV type-1 inhibitors.
Collapse
Affiliation(s)
- Francesco Saladini
- Department of Medical Biotechnologies, University of Siena Italy, Policlinico Le Scotte, Viale Bracci 16 53100 Siena, Italy
| | - Ilaria Vicenti
- Department of Medical Biotechnologies, University of Siena Italy, Policlinico Le Scotte, Viale Bracci 16 53100 Siena, Italy
| |
Collapse
|
9
|
Transient HIV-1 Gag-protease interactions revealed by paramagnetic NMR suggest origins of compensatory drug resistance mutations. Proc Natl Acad Sci U S A 2016; 113:12456-12461. [PMID: 27791180 DOI: 10.1073/pnas.1615342113] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cleavage of the group-specific antigen (Gag) polyprotein by HIV-1 protease represents the critical first step in the conversion of immature noninfectious viral particles to mature infectious virions. Selective pressure exerted by HIV-1 protease inhibitors, a mainstay of current anti-HIV-1 therapies, results in the accumulation of drug resistance mutations in both protease and Gag. Surprisingly, a large number of these mutations (known as secondary or compensatory mutations) occur outside the active site of protease or the cleavage sites of Gag (located within intrinsically disordered linkers connecting the globular domains of Gag to one another), suggesting that transient encounter complexes involving the globular domains of Gag may play a role in guiding and facilitating access of the protease to the Gag cleavage sites. Here, using large fragments of Gag, as well as catalytically inactive and active variants of protease, we probe the nature of such rare encounter complexes using intermolecular paramagnetic relaxation enhancement, a highly sensitive technique for detecting sparsely populated states. We show that Gag-protease encounter complexes are primarily mediated by interactions between protease and the globular domains of Gag and that the sites of transient interactions are correlated with surface exposed regions that exhibit a high propensity to mutate in the presence of HIV-1 protease inhibitors.
Collapse
|
10
|
HIV-1 drug resistance and resistance testing. INFECTION GENETICS AND EVOLUTION 2016; 46:292-307. [PMID: 27587334 DOI: 10.1016/j.meegid.2016.08.031] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/24/2016] [Accepted: 08/27/2016] [Indexed: 12/23/2022]
Abstract
The global scale-up of antiretroviral (ARV) therapy (ART) has led to dramatic reductions in HIV-1 mortality and incidence. However, HIV drug resistance (HIVDR) poses a potential threat to the long-term success of ART and is emerging as a threat to the elimination of AIDS as a public health problem by 2030. In this review we describe the genetic mechanisms, epidemiology, and management of HIVDR at both individual and population levels across diverse economic and geographic settings. To describe the genetic mechanisms of HIVDR, we review the genetic barriers to resistance for the most commonly used ARVs and describe the extent of cross-resistance between them. To describe the epidemiology of HIVDR, we summarize the prevalence and patterns of transmitted drug resistance (TDR) and acquired drug resistance (ADR) in both high-income and low- and middle-income countries (LMICs). We also review to two categories of HIVDR with important public health relevance: (i) pre-treatment drug resistance (PDR), a World Health Organization-recommended HIVDR surveillance metric and (ii) and pre-exposure prophylaxis (PrEP)-related drug resistance, a type of ADR that can impact clinical outcomes if present at the time of treatment initiation. To summarize the implications of HIVDR for patient management, we review the role of genotypic resistance testing and treatment practices in both high-income and LMIC settings. In high-income countries where drug resistance testing is part of routine care, such an understanding can help clinicians prevent virological failure and accumulation of further HIVDR on an individual level by selecting the most efficacious regimens for their patients. Although there is reduced access to diagnostic testing and to many ARVs in LMIC, understanding the scientific basis and clinical implications of HIVDR is useful in all regions in order to shape appropriate surveillance, inform treatment algorithms, and manage difficult cases.
Collapse
|
11
|
Vardhanabhuti S, Katzenstein D, Bartlett J, Kumarasamy N, Wallis CL. Human Immunodeficiency Virus-1 Sequence Changes and Drug Resistance Mutation Among Virologic Failures of Lopinavir/Ritonavir Monotherapy: AIDS Clinical Trials Group Protocol A5230. Open Forum Infect Dis 2016; 3:ofw154. [PMID: 27704010 PMCID: PMC5047431 DOI: 10.1093/ofid/ofw154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/17/2016] [Indexed: 12/12/2022] Open
Abstract
Background. The mechanism of virologic failure (VF) of lopinavir/ritonavir (LPV/r) monotherapy is not well understood. We assessed sequence changes in human immunodeficiency virus-1 reverse-transcriptase (RT) and protease (PR) regions. Methods. Human immunodeficiency virus-1 pol sequences from 34 participants who failed second-line LPV/r monotherapy were obtained at study entry (SE) and VF. Sequence changes were evaluated using phylogenetic analysis and hamming distance. Results. Human immunodeficiency virus-1 sequence change was higher over drug resistance mutation (DRM) sites (median genetic distance, 2.2%; Q1 to Q3, 2.1%–2.5%) from SE to VF compared with non-DRM sites (median genetic distance, 1.3%; Q1 to Q3, 1.0%–1.4%; P < .0001). Evolution over DRM sites was mainly driven by changes in the RT (median genetic distance, 2.7%; Q1 to Q3, 2.2%–3.2%) compared with PR (median genetic distance, 1.1%; Q1 to Q3, 0.0%–1.1%; P < .0001). Most RT DRMs present at SE were lost at VF. At VF, 19 (56%) and 26 (76%) were susceptible to efavirenz/nevirapine and etravirine (ETV)/rilpivirine (RPV), respectively, compared with 1 (3%) and 12 (35%) at SE. Participants who retained nonnucleoside reverse-transcriptase inhibitor (NNRTI) DRMs and those without evolution of LPV/r DRMs had significantly shorter time to VF. Conclusions. The selection of LPV/r DRMs in participants with longer time to VF suggests better adherence and more selective pressure. Fading NNRTI mutations and an increase in genotypic susceptibility to ETV and RPV could allow for the reuse of NNRTI. Further studies are warranted to understand mechanisms of PR failure.
Collapse
Affiliation(s)
| | | | - John Bartlett
- Duke University Medical Center , Durham, North Carolina
| | | | - Carole L Wallis
- Department of Molecular Pathology , Lancet Laboratories and BARC-SA , Johannesburg , South Africa
| |
Collapse
|
12
|
Contribution of Gag and Protease to HIV-1 Phenotypic Drug Resistance in Pediatric Patients Failing Protease Inhibitor-Based Therapy. Antimicrob Agents Chemother 2016; 60:2248-56. [PMID: 26833162 DOI: 10.1128/aac.02682-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/17/2016] [Indexed: 12/15/2022] Open
Abstract
Protease inhibitors (PIs) are used as a first-line regimen in HIV-1-infected children. Here we investigated the phenotypic consequences of amino acid changes in Gag and protease on lopinavir (LPV) and ritonavir (RTV) susceptibility among pediatric patients failing PI therapy. The Gag-protease from isolates from 20 HIV-1 subtype C-infected pediatric patients failing an LPV and/or RTV-based regimen was phenotyped using a nonreplicativein vitroassay. Changes in sensitivity to LPV and RTV relative to that of the matched baseline (pretherapy) sample were calculated. Gag and protease amino acid substitutions associated with PI failure were created in a reference clone by site-directed mutagenesis and assessed. Predicted phenotypes were determined using the Stanford drug resistance algorithm. Phenotypic resistance or reduced susceptibility to RTV and/or LPV was observed in isolates from 10 (50%) patients, all of whom had been treated with RTV. In most cases, this was associated with protease resistance mutations, but substitutions at Gag cleavage and noncleavage sites were also detected. Gag amino acid substitutions were also found in isolates from three patients with reduced drug susceptibilities who had wild-type protease. Site-directed mutagenesis confirmed that some amino acid changes in Gag contributed to PI resistance but only in the presence of major protease resistance-associated substitutions. The isolates from all patients who received LPV exclusively were phenotypically susceptible. Baseline isolates from the 20 patients showed a large (47-fold) range in the 50% effective concentration of LPV, which accounted for most of the discordance seen between the experimentally determined and the predicted phenotypes. Overall, the inclusion of thegaggene and the use of matched baseline samples provided a more comprehensive assessment of the effect of PI-induced amino acid changes on PI resistance. The lack of phenotypic resistance to LPV supports the continued use of this drug in pediatric patients.
Collapse
|
13
|
Sutherland KA, Goodall RL, McCormick A, Kapaata A, Lyagoba F, Kaleebu P, Thiltgen G, Gilks CF, Spyer M, Kityo C, Pillay D, Dunn D, Gupta RK. Gag-Protease Sequence Evolution Following Protease Inhibitor Monotherapy Treatment Failure in HIV-1 Viruses Circulating in East Africa. AIDS Res Hum Retroviruses 2015; 31:1032-7. [PMID: 26258548 PMCID: PMC4675176 DOI: 10.1089/aid.2015.0138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Around 2.5 million HIV-infected individuals failing first-line therapy qualify for boosted protease inhibitor (bPI)-based second-line therapy globally. Major resistance mutations are rarely present at treatment failure in patients receiving bPI and the determinants of failure in these patients remain unknown. There is evidence that Gag can impact PI susceptibility. Here, we have sequenced Gag-Protease before and following failure in 23 patients in the SARA trial infected with subtypes A, C, and D viruses. Before bPI, significant variation in Protease and Gag was observed at positions previously associated with PI exposure and resistance including Gag mutations L449P, S451N, and L453P and Protease K20I and L63P. Following PI failure, previously described mutations in Protease and Gag were observed, including those at the cleavage sites such as R361K and P453L. However, the emergence of clear genetic determinants of therapy failure across patients was not observed. Larger Gag sequence datasets will be required to comprehensively identify mutational correlates of bPI failure across subtypes.
Collapse
Affiliation(s)
| | - Ruth L. Goodall
- MRC Clinical Trials Unit at University College London, London, United Kingdom
| | | | - Anne Kapaata
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | - Fred Lyagoba
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | - Pontiano Kaleebu
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | | | - Charles F. Gilks
- School of Population Health, University of Queensland, Brisbane, Australia
| | - Moira Spyer
- MRC Clinical Trials Unit at University College London, London, United Kingdom
| | - Cissy Kityo
- Joint Clinical Research Centre, Kampala, Uganda
| | - Deenan Pillay
- University College London, London, United Kingdom
- Wellcome Trust Africa Centre for Health and Population Sciences, University of KwaZulu Natal, Mtubatuba, South Africa
| | - David Dunn
- MRC Clinical Trials Unit at University College London, London, United Kingdom
| | | | | | | |
Collapse
|
14
|
Sutherland KA, Parry CM, McCormick A, Kapaata A, Lyagoba F, Kaleebu P, Gilks CF, Goodall R, Spyer M, Kityo C, Pillay D, Gupta RK. Evidence for Reduced Drug Susceptibility without Emergence of Major Protease Mutations following Protease Inhibitor Monotherapy Failure in the SARA Trial. PLoS One 2015; 10:e0137834. [PMID: 26382239 PMCID: PMC4575205 DOI: 10.1371/journal.pone.0137834] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/23/2015] [Indexed: 12/11/2022] Open
Abstract
Background Major protease mutations are rarely observed following failure with protease inhibitors (PI), and other viral determinants of failure to PI are poorly understood. We therefore characterized Gag-Protease phenotypic susceptibility in subtype A and D viruses circulating in East Africa following viral rebound on PIs. Methods Samples from baseline and treatment failure in patients enrolled in the second line LPV/r trial SARA underwent phenotypic susceptibility testing. Data were expressed as fold-change in susceptibility relative to a LPV-susceptible reference strain. Results We cloned 48 Gag-Protease containing sequences from seven individuals and performed drug resistance phenotyping from pre-PI and treatment failure timepoints in seven patients. For the six patients where major protease inhibitor resistance mutations did not emerge, mean fold-change EC50 to LPV was 4.07 fold (95% CI, 2.08–6.07) at the pre-PI timepoint. Following viral failure the mean fold-change in EC50 to LPV was 4.25 fold (95% CI, 1.39–7.11, p = 0.91). All viruses remained susceptible to DRV. In our assay system, the major PI resistance mutation I84V, which emerged in one individual, conferred a 10.5-fold reduction in LPV susceptibility. One of the six patients exhibited a significant reduction in susceptibility between pre-PI and failure timepoints (from 4.7 fold to 9.6 fold) in the absence of known major mutations in protease, but associated with changes in Gag: V7I, G49D, R69Q, A120D, Q127K, N375S and I462S. Phylogenetic analysis provided evidence of the emergence of genetically distinct viruses at the time of treatment failure, indicating ongoing viral evolution in Gag-protease under PI pressure. Conclusions Here we observe in one patient the development of significantly reduced susceptibility conferred by changes in Gag which may have contributed to treatment failure on a protease inhibitor containing regimen. Further phenotype-genotype studies are required to elucidate genetic determinants of protease inhibitor failure in those who fail without traditional resistance mutations whilst PI use is being scaled up globally.
Collapse
Affiliation(s)
| | - Chris M. Parry
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | | | - Anne Kapaata
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | - Fred Lyagoba
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | - Pontiano Kaleebu
- Uganda Research Unit on AIDS, Medical Research Council (MRC), Uganda Virus Research Institute, Entebbe, Uganda
| | - Charles F. Gilks
- School of Population Health, University of Queensland, Brisbane, Australia
| | - Ruth Goodall
- MRC Clinical Trials Unit at UCL, London, United Kingdom
| | - Moira Spyer
- MRC Clinical Trials Unit at UCL, London, United Kingdom
| | - Cissy Kityo
- Joint Clinical Research Centre, Kampala, Uganda
| | - Deenan Pillay
- University College London, London, United Kingdom
- Wellcome Trust Africa Centre for Health and Population Sciences, University of KwaZulu Natal, Mtubatuba, South Africa
- * E-mail: (DP); (RKG)
| | - Ravindra K. Gupta
- University College London, London, United Kingdom
- * E-mail: (DP); (RKG)
| | | |
Collapse
|
15
|
Giandhari J, Basson AE, Coovadia A, Kuhn L, Abrams EJ, Strehlau R, Morris L, Hunt GM. Genetic Changes in HIV-1 Gag-Protease Associated with Protease Inhibitor-Based Therapy Failure in Pediatric Patients. AIDS Res Hum Retroviruses 2015; 31:776-82. [PMID: 25919760 DOI: 10.1089/aid.2014.0349] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Studies have shown a low frequency of HIV-1 protease drug resistance mutations in patients failing protease inhibitor (PI)-based therapy. Recent studies have identified mutations in Gag as an alternate pathway for PI drug resistance in subtype B viruses. We therefore genotyped the Gag and protease genes from 20 HIV-1 subtype C-infected pediatric patients failing a PI-based regimen. Major protease resistance mutations (M46I, I54V, and V82A) were identified in eight (40%) patients, as well as Gag cleavage site (CS) mutations (at codons 373, 374, 378, 428, 431, 449, 451, and 453) in nine (45%) patients. Four of these Gag CS mutations occurred in the absence of major protease mutations at PI failure. In addition, amino acid changes were noted at Gag non-CS with some predicted to be under HLA/KIR immune-mediated pressure and/or drug selection pressure. Changes in Gag during PI failure therefore warrant further investigation of the Gag gene and its role in PI failure in HIV-1 subtype C infection.
Collapse
Affiliation(s)
- Jennifer Giandhari
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), Johannesburg, South Africa
- Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Adriaan E. Basson
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), Johannesburg, South Africa
- Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Ashraf Coovadia
- Empilweni Services and Research Unit, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Louise Kuhn
- Gertrude H. Sergievsky Center, College of Physicians and Surgeons, and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York
| | - Elaine J. Abrams
- International Center for AIDS Programs, Mailman School of Public Health, Columbia University, New York, New York
| | - Renate Strehlau
- Empilweni Services and Research Unit, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Lynn Morris
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), Johannesburg, South Africa
- Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Gillian M. Hunt
- Centre for HIV and STIs, National Institute for Communicable Diseases (NICD), Johannesburg, South Africa
- Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
16
|
Dudley DM, Bailey AL, Mehta SH, Hughes AL, Kirk GD, Westergaard RP, O'Connor DH. Cross-clade simultaneous HIV drug resistance genotyping for reverse transcriptase, protease, and integrase inhibitor mutations by Illumina MiSeq. Retrovirology 2014; 11:122. [PMID: 25533166 PMCID: PMC4302432 DOI: 10.1186/s12977-014-0122-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 12/03/2014] [Indexed: 11/30/2022] Open
Abstract
Background Viral resistance to antiretroviral therapy threatens our best methods to control and prevent HIV infection. Current drug resistance genotyping methods are costly, optimized for subtype B virus, and primarily detect resistance mutations to protease and reverse transcriptase inhibitors. With the increasing use of integrase inhibitors in first-line therapies, monitoring for integrase inhibitor drug resistance mutations is a priority. We designed a universal primer pair to PCR amplify all major group M HIV-1 viruses for genotyping using Illumina MiSeq to simultaneously detect drug resistance mutations associated with protease, nucleoside reverse transcriptase, non-nucleoside reverse transcriptase, and integrase inhibitors. Results A universal primer pair targeting the HIV pol gene was used to successfully PCR amplify HIV isolates representing subtypes A, B, C, D, CRF01_AE and CRF02_AG. The universal primers were then tested on 62 samples from a US cohort of injection drug users failing treatment after release from prison. 94% of the samples were successfully genotyped for known drug resistance mutations in the protease, reverse transcriptase and integrase gene products. Control experiments demonstrate that mutations present at ≥ 2% frequency are reliably detected and above the threshold of error for this method. New drug resistance mutations not found in the baseline sample were identified in 54% of the patient samples after treatment failure. 86% of patients with major drug resistance mutations had 1 or more mutations associated with drug resistance to the treatment regimen at the time point of treatment failure. 59% of the emerging mutations were found at frequencies between 2% and 20% of the total sequences generated, below the estimated limit of detection of current FDA-approved genotyping techniques. Primary plasma samples with viral loads as low as 799 copies/ml were successfully genotyped using this method. Conclusions Here we present an Illumina MiSeq-based HIV drug resistance genotyping assay. Our data suggests that this universal assay works across all major group M HIV-1 subtypes and identifies all drug resistance mutations in the pol gene known to confer resistance to protease, reverse transcriptase and integrase inhibitors. This high-throughput and sensitive assay could significantly improve access to drug resistance genotyping worldwide. Electronic supplementary material The online version of this article (doi:10.1186/s12977-014-0122-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Dawn M Dudley
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Adam L Bailey
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Shruti H Mehta
- Department of Epidemiology, Epidemiology and Oncology, Johns Hopkins University, Baltimore, MD, USA.
| | - Austin L Hughes
- Department of Biology, University of South Carolina, Columbia, South Carolina, USA.
| | - Gregory D Kirk
- Departments of Medicine, Epidemiology and Oncology, Johns Hopkins University, Baltimore, MD, USA.
| | - Ryan P Westergaard
- Department of Medicine, Division of Infectious Disease, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - David H O'Connor
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| |
Collapse
|
17
|
Abstract
Pseudotype viruses: applications and troubleshooting’ (EuroSciCon 2013), a 1-day conference held at Cineworld: The O2 (London, UK) on 2 October 2013, focused on the technique of pseudotyping enveloped viruses (for a review of the technique, see [1]). The talks and posters covered the challenges and successes of pseudotyping viruses from a broad range of families (Retroviridae, Flaviviridae, Orthomyxoviridae, Bunyaviridae and Rhabdoviridae) for a variety of applications. The conference was chaired by Nigel Temperton, University of Kent (UK), who placed a strong emphasis on using this event to explore the technical challenges of pseudotyping viruses, especially during the poster and afternoon question and answer sessions.
Collapse
Affiliation(s)
- Barnabas King
- School of Veterinary Medicine & Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
| | | |
Collapse
|
18
|
Sutherland KA, Ghosn J, Gregson J, Mbisa JL, Chaix ML, Cohen Codar I, Delfraissy JF, Delaugerre C, Gupta RK. HIV-1 subtype influences susceptibility and response to monotherapy with the protease inhibitor lopinavir/ritonavir. J Antimicrob Chemother 2014; 70:243-8. [PMID: 25228587 PMCID: PMC4267506 DOI: 10.1093/jac/dku365] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE PI susceptibility results from a complex interplay between protease and Gag proteins, with Gag showing wide variation across HIV-1 subtypes. We explored the impact of pre-treatment susceptibility on the outcome of lopinavir/ritonavir monotherapy. METHODS Treatment-naive individuals who experienced lopinavir/ritonavir monotherapy failure from the MONARK study were matched (by subtype, viral load and baseline CD4 count) with those who achieved virological response ('successes'). Successes were defined by viral load <400 copies/mL after week 24 and <50 copies/mL from week 48 to week 96. Full-length Gag-protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with susceptibility expressed as fold change (FC) relative to a subtype B reference strain. RESULTS Baseline lopinavir susceptibility was lower in viral failures compared with viral successes, but the differences were not statistically significant (median lopinavir susceptibility: 4.4 versus 8.5, respectively, P = 0.17). Among CRF02_AG/G patients, there was a significant difference in lopinavir susceptibility between the two groups (7.1 versus 10.4, P = 0.047), while in subtype B the difference was not significant (2.7 versus 3.4, P = 0.13). Subtype CRF02_AG/G viruses had a median lopinavir FC of 8.7 compared with 3.1 for subtype B (P = 0.001). CONCLUSIONS We report an association between reduced PI susceptibility (using full-length Gag-protease sequences) at baseline and subsequent virological failure on lopinavir/ritonavir monotherapy in antiretroviral-naive patients harbouring subtype CRF02_AG/G viruses. We speculate that this may be important in the context of suboptimal adherence in determining viral failure.
Collapse
Affiliation(s)
- K A Sutherland
- Virus Reference Department, Public Health England, London, UK Department of Infection, University College London, London, UK
| | - J Ghosn
- Université Paris Descartes, EA 7327, Faculté de Médecine site Necker, Paris, France APHP, UF de thérapeutique en Immuno Infectiologie, CHU Hotel Dieu, Paris, France
| | - J Gregson
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, UK
| | - J L Mbisa
- Virus Reference Department, Public Health England, London, UK
| | - M L Chaix
- Université Paris Descartes, EA 7327, Faculté de Médecine site Necker, Paris, France
| | | | - J F Delfraissy
- AP-HP, Department of Internal Medicine, Bicetre University Hospital, Le Kremlin-Bicetre, France
| | - C Delaugerre
- Virology, U941 INSERM Paris Diderot University, St Louis Hospital-APHP, Paris, France
| | - R K Gupta
- Department of Infection, University College London, London, UK
| |
Collapse
|
19
|
Sutherland KA, Mbisa JL, Ghosn J, Chaix ML, Cohen-Codar I, Hue S, Delfraissy JF, Delaugerre C, Gupta RK. Phenotypic characterization of virological failure following lopinavir/ritonavir monotherapy using full-length Gag-protease genes. J Antimicrob Chemother 2014; 69:3340-8. [PMID: 25096075 PMCID: PMC4228778 DOI: 10.1093/jac/dku296] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Objectives Major protease mutations are rarely observed following first-line failure with PIs and interpretation of genotyping results in this context may be difficult. We performed extensive phenotyping of viruses from five patients failing lopinavir/ritonavir monotherapy in the MONARK study without major PI mutations by standard genotyping. Methods Phenotypic susceptibility testing and viral infectivity assessments were performed using a single-cycle assay and fold changes (FC) relative to a lopinavir-susceptible reference strain were calculated. Results >10-fold reduced baseline susceptibility to lopinavir occurred in two of five patients and >5-fold in another two. Four of five patients exhibited phylogenetic evidence of a limited viral evolution between baseline and failure, with amino acid changes at drug resistance-associated positions in one: T81A emerged in Gag with M36I in the protease gene, correlating with a reduction in lopinavir susceptibility from FC 7 (95% CI 6–8.35) to FC 13 (95% CI 8.11–17.8). Reductions in darunavir susceptibility (>5 FC) occurred in three individuals. Discussion This study suggests both baseline reduced susceptibility and evolution of resistance could be contributing factors to PI failure, despite the absence of classical PI resistance mutations by standard testing methods. Use of phenotyping also reveals lower darunavir susceptibility, warranting further study as this agent is commonly used following lopinavir failure.
Collapse
Affiliation(s)
| | | | - Jade Ghosn
- Université Paris Descartes, EA 7327, Faculté de Médecine Site Necker, Paris, France APHP, UF de Thérapeutique en Immuno Infectiologie, CHU Hotel Dieu, Paris, France
| | - Marie-Laure Chaix
- Université Paris Descartes, EA 7327, Faculté de Médecine Site Necker, Paris, France
| | | | - Stephane Hue
- Division of Infection and Immunity, University College London, London, UK
| | | | - Constance Delaugerre
- Virology, U941 INSERM Paris Diderot University, St Louis Hospital-APHP, Paris, France
| | - Ravindra K Gupta
- Division of Infection and Immunity, University College London, London, UK
| |
Collapse
|