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During COVID-19 lockdown, the in-hospital number of HIV indicator conditions decreased disproportionally compared with other non-COVID-19 diseases, which was accompanied by reduced HIV testing rates, number and proportion of positive HIV tests, and new HIV referrals, with more late presentation after lockdown cessation, indicating a significantly impacted HIV care continuum.
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COVID-19 , Infecções por HIV , Controle de Doenças Transmissíveis , Continuidade da Assistência ao Paciente , HIV , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Hospitais , Humanos , SARS-CoV-2RESUMO
BACKGROUND: Letermovir is a novel cytomegalovirus antiviral that is approved for prophylaxis in hematopoietic stem cell transplantation recipients. METHODS: After obtaining informed consent, letermovir prophylaxis was started in a patient with a presumed late-onset primary, combined T- and B-cell immunodeficiency. Plasma CMV DNAemia was monitored with real-time polymerase chain reaction, and letermovir resistance analyses were performed using Sanger sequencing and Illumina MiSeq next-generation sequencing. RESULTS: A letermovir-resistant cytomegalovirus variant (C325Y mutation in UL56) emerged 17 weeks after start of prophylaxis. The letermovir-resistant variant was able to reactivate without drug selective pressure as this variant was again detected in plasma 20.6 weeks after stopping of letermovir. CONCLUSIONS: This case indicates that the C325Y mutation in UL56 does not significantly alter fitness of cytomegalovirus in vivo.
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BackgroundPre-exposure prophylaxis (PrEP) is a highly effective HIV prevention strategy for men-who-have-sex-with-men (MSM). The high cost of PrEP has until recently been a primary barrier to its use. In 2017, generic PrEP became available, reducing the costs by 90%.AimOur objective was to assess cost-effectiveness and costs of introducing PrEP in Germany.MethodsWe calibrated a deterministic mathematical model to the human immunodeficiency virus (HIV) epidemic among MSM in Germany. PrEP was targeted to 30% of high-risk MSM. It was assumed that PrEP reduces the risk of HIV infection by 85%. Costs were calculated from a healthcare payer perspective using a 40-year time horizon starting in 2018.ResultsPrEP can avert 21,000 infections (interquartile range (IQR): 16,000-27,000) in the short run (after 2 years scale-up and 10 years full implementation). HIV care is predicted to cost EUR 36.2 billion (IQR: 32.4-40.4 billion) over the coming 40 years. PrEP can increase costs by at most EUR 150 million within the first decade after introduction. Ten years after introduction, PrEP can become cost-saving, accumulating to savings of HIV-related costs of EUR 5.1 billion (IQR: 3.5-6.9 billion) after 40 years. In a sensitivity analysis, PrEP remained cost-saving even at a 70% price reduction of antiretroviral drug treatment and a lower effectiveness of PrEP.ConclusionIntroduction of PrEP in Germany is predicted to result in substantial health benefits because of reductions in HIV infections. Short-term financial investments in providing PrEP will result in substantial cost-savings in the long term.
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Fármacos Anti-HIV/economia , Antirretrovirais/economia , Análise Custo-Benefício , Infecções por HIV/prevenção & controle , Profilaxia Pré-Exposição/economia , Fármacos Anti-HIV/administração & dosagem , Antirretrovirais/administração & dosagem , Alemanha , Infecções por HIV/economia , Infecções por HIV/transmissão , HIV-1 , Homossexualidade Masculina , Humanos , Masculino , Programas de Rastreamento/economia , Modelos Teóricos , Profilaxia Pré-Exposição/métodosRESUMO
BACKGROUND: HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe. METHODS: This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence. The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence. RESULTS: At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32-3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by analysing drug-naïve patients (29.5% vs 21.2%, P = 0.032). Strong correlation was observed between sP120T and rtM204I/V (P < 0.001), and their co-presence determined an increased HBV-DNA. At least one NA-induced immune-escape mutation occurred in 28.6% of patients, and their selection correlated with genotype-A (OR[95%CI]:2.03[1.32-3.10],P = 0.001). Finally, stop-codons are present in 8.4% of patients also at HBsAg-positions 172 and 182, described to enhance viral oncogenic-properties. CONCLUSIONS: Immune-escape mutations and stop-codons develop in a large fraction of NA-exposed patients from Europe. This may represent a potential threat for horizontal and vertical HBV transmission also to vaccinated persons, and fuel drug-resistance emergence.
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Antivirais/uso terapêutico , Códon de Terminação , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/imunologia , Mutação , Adulto , Substituição de Aminoácidos , Europa (Continente) , Feminino , Genótipo , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Background: A high genetic barrier to resistance to the integrase strand transfer inhibitor (INSTI) dolutegravir has been reported in vitro and in vivo. We describe the dynamics of INSTI resistance-associated mutations (INSTI-RAMs) and mutations in the 3'-polypurine tract (3'-PPT) in relation to virologic failure (VF) observed in the randomized Dolutegravir as Maintenance Monotherapy for HIV-1 study (DOMONO, NCT02401828). Methods: From 10 patients with VF, plasma samples were collected before the start of cART and during VF, and were used to generate Sanger sequences of integrase, the 5' terminal bases of the 3' long terminal repeat (LTR), and the 3'-PPT. Results: Median human immunodeficiency virus RNA load at VF was 3490 copies/mL (interquartile range 1440-4990 copies/mL). INSTI-RAMs (S230R, R263K, N155H, and E92Q+N155H) were detected in 4 patients, no INSTI-RAMs were detected in 4 patients, and sequencing of the integrase gene was unsuccessful in 2 patients. The time to VF ranged from 4 weeks to 72 weeks. In 1 patient, mutations developed in the highly conserved 3'-PPT. No changes in the terminal bases of the 3'-LTR were observed. Conclusions: The genetic barrier to resistance is too low to justify dolutegravir maintenance monotherapy because single INSTI-RAMs are sufficient to cause VF. The large variation in time to VF suggests that stochastic reactivation of a preexisting provirus containing a single INSTI-RAM is the mechanism for failure. Changes in the 3'-PPT point to a new dolutegravir resistance mechanism in vivo. Clinical Trials Registration: NCT02401828.
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Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Inibidores de Integrase de HIV/administração & dosagem , HIV-1/efeitos dos fármacos , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Mutação , Adulto , Feminino , HIV-1/isolamento & purificação , Humanos , Quimioterapia de Manutenção/métodos , Masculino , Pessoa de Meia-Idade , Oxazinas , Piperazinas , Piridonas , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Sequência de DNA , Falha de Tratamento , Carga ViralRESUMO
The Netherlands has approximately 20,000 registered HIV-infected patients. The current HIV prevention policy consisting of condom use and active HIV testing does not effectively mitigate the HIV epidemic in all risk groups. In July of 2012, tenofovir/emtricitabine (TDF/FTC) was approved by the American Food and Drug Administration (FDA) for pre-exposure prophylaxis (PrEP) for long-term use in persons who exhibit frequent risky and unsafe sexual behaviour. With once-daily use and good therapy compliance, TDF/FTC has proved to be effective as PrEP, and few side effects are reported. Drawbacks in the use of TDF/FTC as PrEP are the potential risk of viral resistance and reduced condom use, the relatively high cost and the intensive counselling required. In special cases, long-term PrEP could enhance the current Dutch preventive policy. Further research is needed into the practical feasibility and protective efficacy of the ad hoc use of TDF/FTC as PrEP before a high-risk contact occurs.
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Adenina/análogos & derivados , Fármacos Anti-HIV/administração & dosagem , Quimioprevenção , Desoxicitidina/análogos & derivados , Infecções por HIV/prevenção & controle , Organofosfonatos/administração & dosagem , Adenina/administração & dosagem , Desoxicitidina/administração & dosagem , Emtricitabina , Infecções por HIV/transmissão , Humanos , Países Baixos , Cooperação do Paciente , Assunção de Riscos , Comportamento Sexual , TenofovirRESUMO
The virological response and development of drug resistance during first-line anti-retroviral treatment (ART) were studied in Indonesia where the majority of patients infected with HIV have a history of injecting drug use, which is often linked with lower treatment adherence and development of drug-resistance. As many as 575 patients starting ART between September 2007 and March 2010 in Hasan Sadikin Hospital Bandung were followed prospectively. Clinical and laboratory monitoring was performed every 6 months. Plasma samples with HIV-RNA ≥ 400 copies/ml were examined for drug resistance mutations. Most patients were male (72.3%), 59.7% had a history of injecting drug use, and the median CD4+ cells count before start of ART was 35 cells/mm(3) (IQR 10-104). From 438 HIV patients with HIV-RNA measurements, 40 (9.1%) subjects had HIV-RNA ≥ 400 copies/ml after 24 weeks (median follow-up 16 (IQR 8-25) months). Of these failing patients 16 (47%) subjects had drug resistance mutations, predominantly M184V (35.3%), Y181C (23.5%), K103N (11.7%), and TAMs (11.7%). A history of treatment discontinuation ≥ 1 month, reported by 5.3% (23) of patients, was strongly associated with virological failure (adjusted OR 12.64, 95% CI 4.51-35.41); and a history of injecting drug use was not (OR 0.75, 95% CI 0.38-1.46). This is the largest and most systematic evaluation of virological response to first line ART in Indonesia. Patients in this cohort responded well to first line ART, with low rates of virological failure and drug resistance. A history of injecting drug use should not be a reason to withhold ART in this setting.
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Antirretrovirais/uso terapêutico , Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV/efeitos dos fármacos , Adulto , Feminino , Seguimentos , HIV/genética , HIV/isolamento & purificação , Humanos , Indonésia , Masculino , Mutação de Sentido Incorreto , Estudos Prospectivos , RNA Viral/sangue , RNA Viral/genética , Falha de Tratamento , Carga Viral , Adulto JovemRESUMO
We report a case of an HIV-infected patient who was successfully treated with ritonavir/lopinavir (r/LPV) monotherapy for several years. He presented with neurological symptoms and high HIV RNA levels in cerebrospinal fluid (CSF). Sequencing of the HIV from the CSF revealed mutations in the protease gene reflecting resistance against most protease inhibitors, that is, lopinavir and ritonavir. His regimen was switched and after 2 months the HIV RNA viral load was again undetectable in both plasma as well as in CSF. Monotherapy with r/LPV may not be sufficient to fully suppress viral replication in the central nervous system in all individuals and may lead to compartimentalization and the selection of resistant mutations of HIV in the central nervous system.
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Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/uso terapêutico , HIV/fisiologia , Lopinavir/uso terapêutico , RNA Viral/líquido cefalorraquidiano , Ritonavir/uso terapêutico , Farmacorresistência Viral/genética , HIV/efeitos dos fármacos , Infecções por HIV/líquido cefalorraquidiano , Infecções por HIV/fisiopatologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Análise de Sequência de RNA , Carga Viral/efeitos dos fármacos , Replicação ViralRESUMO
Respiratory infections caused by respiratory viruses are common in paediatric cystic fibrosis (CF) patients and are associated with increased morbidity. There is only little data on the incidence of viral respiratory pathogens causing exacerbations in the adult CF patient population. In this observational pilot study we show, by using molecular as well as conventional techniques for viral isolation, that during 1 y a viral pathogen could be isolated in 8/24 (33%) adult CF patients who presented with a pulmonary exacerbation. This result shows that there is a considerable incidence of viral pathogens in pulmonary exacerbations in adult CF patients. Newly identified viruses such as pandemic influenza A/H1N1, human metapneumovirus, human bocavirus, and human coronavirus NL63 were not detected in our population, except for 1 human coronavirus NL63.
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Fibrose Cística/virologia , Infecções Respiratórias/virologia , Viroses/complicações , Adulto , Feminino , Humanos , Incidência , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escarro/virologia , Viroses/virologia , Vírus/genética , Vírus/isolamento & purificaçãoAssuntos
Antivirais/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Neuraminidase/antagonistas & inibidores , Neuraminidase/genética , Substituição de Aminoácidos , Pré-Escolar , Surtos de Doenças , Inibidores Enzimáticos/uso terapêutico , Evolução Fatal , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/etiologia , Masculino , Mutação , Oseltamivir/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Carga Viral , Zanamivir/uso terapêuticoRESUMO
PURPOSE OF REVIEW: Results of trials determining if pre-exposure prophylaxis (PrEP) with antiretroviral drugs prevents transmission of HIV are expected soon. Tenofovir and emtricitabine--currently evaluated as PrEP--are popular in treatment of HIV. Drug resistance could, therefore, be critical in the use of PrEP. We review the literature regarding risks associated with drug resistance owing to PrEP. RECENT FINDINGS: Few studies addressed the issue of drug resistance to tenofovir and/or emtricitabine. Studies in HIV-1-infected individuals followed small numbers of patients for a short time. Studies in macaques were well designed, but used SHIV, which has an attenuated course of infection. The available information suggests that the probability of emergence of drug resistance is small. Infections that occurred despite use of PrEP had reduced peak viremia, which could reduce HIV transmissibility. Mathematical modeling suggests that, although transmitted drug resistance may under some circumstances increase, the benefits of PrEP outweigh the risks associated with resistance. SUMMARY: Tenofovir and emtricitabine are recommended in first-line treatment. The potentially limited impact of drug resistance should, therefore, be confirmed in daily practice. Surveillance of drug resistance is recommended in areas where PrEP is used. Patients that became infected despite use of PrEP should be closely monitored for virological failure.
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Adenina/análogos & derivados , Fármacos Anti-HIV/farmacologia , Desoxicitidina/análogos & derivados , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , HIV/efeitos dos fármacos , Organofosfonatos/farmacologia , Adenina/administração & dosagem , Adenina/farmacologia , Adenina/uso terapêutico , Animais , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/uso terapêutico , Desoxicitidina/administração & dosagem , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Esquema de Medicação , Farmacorresistência Viral , Quimioterapia Combinada , Emtricitabina , HIV/fisiologia , Infecções por HIV/virologia , Humanos , Organofosfonatos/administração & dosagem , Organofosfonatos/uso terapêutico , Medição de Risco , Tenofovir , Viremia/tratamento farmacológicoRESUMO
A 58-year-old man was submitted to our intensive care ward with respiratory failure due to pneumonitis. He had previously been treated for non-Hodgkin lymphoma by autologous stem cell transplantation, as a result of which bone marrow function was reduced. Further analysis showed infection with new influenza A(H1N1); typing revealed an oseltamivir-resistant subpopulation (H275Y). The patient was treated with oseltamivir and intravenously with zanamivir, but died of respiratory disease progression. This is the first published case of oseltamivir-resistant new influenza A(H1N1) infection in the Netherlands.
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Antivirais/farmacologia , Farmacorresistência Viral , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Oseltamivir/farmacologia , Pneumonia/tratamento farmacológico , Pneumonia/virologia , Antivirais/uso terapêutico , Evolução Fatal , Humanos , Hospedeiro Imunocomprometido , Influenza Humana/complicações , Masculino , Pessoa de Meia-Idade , Oseltamivir/uso terapêutico , Zanamivir/farmacologia , Zanamivir/uso terapêuticoRESUMO
BACKGROUND: Virological failure of first-line antiretroviral therapy based on lopinavir boosted with ritonavir (lopinavir/r) has rarely been associated with resistance in protease. We identified a new genotypic resistance pathway in 3 patients who experienced failure of first-line lopinavir/r treatment. METHODS: Viral protease and the C-term part of Gag were sequenced. The observed mutations were introduced in a reference strain to investigate impact on protease inhibitor susceptibility and replication capacity. RESULTS: A detailed longitudinal analysis demonstrated the selection of the M46I+L76V protease mutations in all 3 patients. The L76V conferred a solitary 3.5-fold increase in one-half the maximal inhibitory concentration to lopinavir but severely hampered viral replication. Addition of M46I, which did not confer any lopinavir resistance on its own, had a dual effect. It partly compensated for the loss in replication capacity and increased the one-half maximal inhibitory concentration to above the lower clinical cutoff (11-fold). Analysis of a large clinical database (>180,000 human immunodeficiency virus [HIV] sequences) demonstrated a significant association (Spearman rho, 0.93) between the increased presence of L76V in clinical samples (0.5% in 2000 to 3.4% in 2006) and lopinavir prescription over time. CONCLUSIONS: The HIV protease substitution L76V, in combination with M46I, confers clinically relevant levels of lopinavir resistance and represents a novel resistance pathway to first-line lopinavir/r therapy.
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Fármacos Anti-HIV/uso terapêutico , Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Protease de HIV/genética , HIV/efeitos dos fármacos , Mutação de Sentido Incorreto , Pirimidinonas/uso terapêutico , Ritonavir/uso terapêutico , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Fármacos Anti-HIV/farmacologia , Análise Mutacional de DNA , HIV/genética , Humanos , Estudos Longitudinais , Lopinavir , Dados de Sequência Molecular , Filogenia , Pirimidinonas/farmacologia , Ritonavir/farmacologia , Análise de Sequência de DNA , Homologia de Sequência , Falha de Tratamento , Replicação Viral/efeitos dos fármacos , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genéticaRESUMO
Peptides based on heptad repeat (HR) domains of class I viral fusion proteins are considered promising antiviral drugs targeting virus cell entry. We have analyzed the evolution of the mouse hepatitis coronavirus during multiple passaging in the presence of an HR2-based fusion inhibitor. Drug-resistant variants emerged as a result of multiple substitutions in the spike fusion protein, notably within a 19-residue segment of the HR1 region. Strikingly, one mutation, an A1006V substitution, which consistently appeared first in four independently passaged viruses, was the main determinant of the resistance phenotype, suggesting that only limited options exist for escape from the inhibitory effect of the HR2 peptide.
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Coronavirus/fisiologia , Fusão de Membrana , Glicoproteínas de Membrana/química , Mutação , Peptídeos/fisiologia , Proteínas do Envelope Viral/química , Animais , Linhagem Celular , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Camundongos , Sequências Repetitivas de Aminoácidos , Glicoproteína da Espícula de Coronavírus , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/fisiologiaRESUMO
The 2008 International HIV Drug Resistance Workshop explored six topics on viral resistance: new antiretrovirals; clinical implications; epidemiology; new technologies and interpretations; HIV pathogenesis, fitness, and resistance; and mechanisms of resistance. The last of these topics provided a forum for new work on resistance of hepatitis B and C viruses, which were also explored in two poster sessions. Much work focused on resistance to the two most recent antiretroviral classes (integrase inhibitors and CCR5 antagonists), a new set of entry inhibitor candidates and one new class represented by the maturation inhibitor bevirimat. Other research explored two novel non-nucleoside reverse transcriptase inhibitors, etravirine and IDX899. Epidemiological work analysed rates of transmitted resistant virus, multiclass resistance in antiretroviral-experienced patients and a heightened resistance risk in injecting drug users regardless of adherence. New research on resistance technologies involved an enhanced assay for HIV-1 coreceptor determination and improved gene-based tools for predicting coreceptor use. In the pathogenesis arena, a small study of intensification shed light on the likely source of residual viraemia in patients on successful antiretroviral therapy. A large study in Mozambique correlated the timing of infant infection with selection, transmission and persistence of nevirapine resistance mutations. Mechanistic research explored resistance to the integrase inhibitor raltegravir, K65R-mediated resistance to tenofovir and the role of connection domain mutations in resistance to zidovudine.
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Fármacos Anti-HIV/farmacologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV/efeitos dos fármacos , Farmacorresistência Viral Múltipla , Infecções por HIV/epidemiologia , Humanos , Mutação , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: HIV protease inhibitor (PI) therapy results in the rapid selection of drug resistant viral variants harbouring one or two substitutions in the viral protease. To combat PI resistance development, two approaches have been developed. The first is to increase the level of PI in the plasma of the patient, and the second is to develop novel PI with high potency against the known PI-resistant HIV protease variants. Both approaches share the requirement for a considerable increase in the number of protease mutations to lead to clinical resistance, thereby increasing the genetic barrier. We investigated whether HIV could yet again find a way to become less susceptible to these novel inhibitors. METHODS AND FINDINGS: We have performed in vitro selection experiments using a novel PI with an increased genetic barrier (RO033-4649) and demonstrated selection of three viruses 4- to 8-fold resistant to all PI compared to wild type. These PI-resistant viruses did not have a single substitution in the viral protease. Full genomic sequencing revealed the presence of NC/p1 cleavage site substitutions in the viral Gag polyprotein (K436E and/or I437T/V) in all three resistant viruses. These changes, when introduced in a reference strain, conferred PI resistance. The mechanism leading to PI resistance is enhancement of the processing efficiency of the altered substrate by wild-type protease. Analysis of genotypic and phenotypic resistance profiles of 28,000 clinical isolates demonstrated the presence of these NC/p1 cleavage site mutations in some clinical samples (codon 431 substitutions in 13%, codon 436 substitutions in 8%, and codon 437 substitutions in 10%). Moreover, these cleavage site substitutions were highly significantly associated with reduced susceptibility to PI in clinical isolates lacking primary protease mutations. Furthermore, we used data from a clinical trial (NARVAL, ANRS 088) to demonstrate that these NC/p1 cleavage site changes are associated with virological failure during PI therapy. CONCLUSIONS: HIV can use an alternative mechanism to become resistant to PI by changing the substrate instead of the protease. Further studies are required to determine to what extent cleavage site mutations may explain virological failure during PI therapy.
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Farmacorresistência Viral/genética , Inibidores da Protease de HIV/farmacologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Mutação , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Linhagem Celular , Códon/genética , Mutação da Fase de Leitura , Produtos do Gene gag/genética , Produtos do Gene gag/metabolismo , Genoma Viral , Protease de HIV/genética , Protease de HIV/metabolismo , Transcriptase Reversa do HIV/genética , Transcriptase Reversa do HIV/metabolismo , Humanos , Immunoblotting , Dados de Sequência Molecular , RNA Viral/genética , Ritonavir/farmacologia , Especificidade por Substrato , TransfecçãoRESUMO
OBJECTIVE: To investigate the mechanism explaining the persistence of human immunodeficiency virus (HIV) type 1 variants with multiple protease inhibitor (PI)-resistance mutations in the absence of PI therapy. METHODS: Longitudinal genotypic analyses were performed on sequential samples obtained from 2 HIV-1-infected patients who had stopped PI therapy for 4 years. Replication capacity (RC) was determined using recombinant viruses. Subsequently, the effect that changing individual protease mutations back to wild type has on RC was analyzed. RESULTS: We observed prolonged persistence (up to 4 years) of viruses with multiple protease mutations after PI therapy was stopped, despite the fact that the RC of the viruses was severely reduced. Forcing the virus to evolve toward wild type by changing individual protease mutations to wild type was unsuccessful, because all variants displayed a decreased RC in comparison with that of their predecessors. CONCLUSIONS: We propose compensatory fixation as a mechanism for the in vivo persistence of variants with multiple PI-resistance mutations in the absence of PI therapy. Viruses with multiple PI mutations have (partially) compensated for the initial loss in RC. Therefore, reversion of a single mutation causes a (further) reduction in RC and, as a consequence, the route to wild type is blocked.