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1.
Clin Infect Dis ; 74(5): 865-870, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-34117753

RESUMO

BACKGROUND: Development of human immunodeficiency virus (HIV) remission strategies requires precise information on time to HIV rebound after treatment interruption, but there is uncertainty regarding whether modern antiretroviral therapy (ART) regimens and timing of ART initiation may affect this outcome. METHODS: AIDS Clinical Trials Group (ACTG) A5345 enrolled individuals who initiated ART during chronic or early HIV infection and on suppressive ART for ≥2 years. Participants underwent carefully monitored antiretroviral interruption. ART was restarted upon 2 successive viral loads ≥1000 copies/mL. We compared participants of A5345 with participants of 6 historic ACTG treatment interruption studies. RESULTS: Thirty-three chronic-treated and 12 early-treated participants interrupted ART with evaluable time to viral rebound. Median time to viral rebound ≥1000 HIV RNA copies/mL was 22 days. Acute retroviral rebound syndrome was diagnosed in 9% of the chronic-treated and none of the early-treated individuals. All participants of the historic studies were on older protease inhibitor-based regimens, whereas 97% of A5345 participants were on integrase inhibitor-based ART. There were no differences in the timing of viral rebound comparing A5345 versus historic studies. In a combined analysis, a higher percentage of early-treated participants remained off ART at posttreatment interruption week 12 (chronic vs early: 2% vs 9%, P = .0496). One chronic-treated and one early-treated A5345 participant remained off ART for >24 weeks. All participants resuppressed after ART reinitiation. CONCLUSIONS: Early ART initiation, using either older or newer ART regimens, was associated with a significant delay in the time to HIV rebound after ART interruption, lowering the barrier for HIV remission.


Assuntos
Infecções por HIV , Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Humanos , Carga Viral
2.
Clin Infect Dis ; 73(3): e643-e651, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-33382405

RESUMO

BACKGROUND: Antiretroviral therapy (ART) initiation during acute and early human immunodeficiency virus infection (AEHI) limits HIV reservoir formation and may facilitate post-ART control but is logistically challenging. We evaluated the performance of AEHI diagnostic criteria from a prospective study of early ART initiation. METHODS: AIDS Clinical Trials Group A 5354 enrolled adults at 30 sites in the Americas, Africa, and Asia who met any 1 of 6 criteria based on combinations of results of HIV RNA, HIV antibody, Western blot or Geenius assay, and/or the signal-to-cutoff (S/CO) ratio of the ARCHITECT HIV Ag/Ab Combo or GS HIV Combo Ag/Ab EIA. HIV status and Fiebig stage were confirmed by centralized testing. RESULTS: From 2017 through 2019, 195 participants were enrolled with median age of 27 years (interquartile range, 23-39). Thirty (15.4%) were female. ART was started by 171 (87.7%) on the day of enrollment and 24 (12.3%) the next day. AEHI was confirmed in 188 (96.4%) participants after centralized testing, 4 (2.0%) participants were found to have chronic infection, and 3 (1.5%) found not to have HIV discontinued ART and were withdrawn. Retrospectively, a nonreactive or indeterminate HIV antibody on the Geenius assay combined with ARCHITECT S/CO ≥10 correctly identified 99 of 122 (81.2%) Fiebig II-IV AEHI cases with no false-positive results. CONCLUSIONS: Novel AEHI criteria that incorporate ARCHITECT S/CO facilitated rapid and efficient ART initiation without waiting for an HIV RNA result. These criteria may facilitate AEHI diagnosis, staging, and immediate ART initiation in future research studies and clinical practice. CLINICAL TRIALS REGISTRATION: NCT02859558.


Assuntos
Infecções por HIV , HIV-1 , Adulto , África , Ásia , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Humanos , Estudos Prospectivos , Estudos Retrospectivos
3.
J Clin Microbiol ; 54(7): 1871-1876, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27194685

RESUMO

Staphylococcus aureus is one of the most important pathogens causing contagious mastitis in dairy cattle worldwide. The objectives of this study were to determine if recently described S. aureus genotype B was present among previously characterized isolates from cases of bovine intramammary infection in the United States and to compare pulsed-field gel electrophoresis (PFGE) to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for typing of S. aureus strains. The hypothesis was that isolates that were previously characterized as contagious would be identified as genotype B and that the results of the two strain-typing methods would be comparable. Isolates were selected from a collection of S. aureus isolates from eight dairy farms. Mammary quarter milk somatic cell count (SCC) and N-acetyl-ß-d-gluconaminidase (NAGase) activity data were known and used to evaluate strain pathogenicity. RS-PCR was performed with conventional gel electrophoresis, and PCR was used for toxin gene identification. RS-PCR patterns were associated with a specific virulence gene pattern, as previously reported. Five RS-PCR banding patterns were identified. None of the isolates were characterized as genotype B. No association between RS-PCR types and milk SCC was found; however, NAGase activity was significantly higher in milk from mammary glands infected with RS-PCR banding type 1 (RSP type 1) than in milk from those infected with RSP type 2. The discriminatory power values were 1.0 and 0.46 for PFGE and RS-PCR, respectively. These data suggest that genotype B may have a limited geographic distribution and that PFGE is more discriminatory than RS-PCR performed with conventional gel electrophoresis for typing of S. aureus isolates of bovine origin.


Assuntos
Infecções Assintomáticas , Genótipo , Mastite Bovina/microbiologia , Tipagem Molecular/métodos , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Animais , Bovinos , Eletroforese em Gel de Campo Pulsado/métodos , Feminino , Mastite Bovina/patologia , Reação em Cadeia da Polimerase/métodos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/isolamento & purificação , Estados Unidos , Virulência , Fatores de Virulência/análise , Fatores de Virulência/genética
4.
N Engl J Med ; 365(16): 1471-81, 2011 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-22010913

RESUMO

BACKGROUND: Tuberculosis remains an important cause of death among patients infected with the human immunodeficiency virus (HIV). Robust data are lacking with regard to the timing for the initiation of antiretroviral therapy (ART) in relation to the start of antituberculosis therapy. METHODS: We tested the hypothesis that the timing of ART initiation would significantly affect mortality among adults not previously exposed to antiretroviral drugs who had newly diagnosed tuberculosis and CD4+ T-cell counts of 200 per cubic millimeter or lower. After beginning the standard, 6-month treatment for tuberculosis, patients were randomly assigned to either earlier treatment (2 weeks after beginning tuberculosis treatment) or later treatment (8 weeks after) with stavudine, lamivudine, and efavirenz. The primary end point was survival. RESULTS: A total of 661 patients were enrolled and were followed for a median of 25 months. The median CD4+ T-cell count was 25 per cubic millimeter, and the median viral load was 5.64 log(10) copies per milliliter. The risk of death was significantly reduced in the group that received ART earlier, with 59 deaths among 332 patients (18%), as compared with 90 deaths among 329 patients (27%) in the later-ART group (hazard ratio, 0.62; 95% confidence interval [CI]; 0.44 to 0.86; P=0.006). The risk of tuberculosis-associated immune reconstitution inflammatory syndrome was significantly increased in the earlier-ART group (hazard ratio, 2.51; 95% CI, 1.78 to 3.59; P<0.001). Irrespective of the study group, the median gain in the CD4+ T-cell count was 114 per cubic millimeter, and the viral load was undetectable at week 50 in 96.5% of the patients. CONCLUSIONS: Initiating ART 2 weeks after the start of tuberculosis treatment significantly improved survival among HIV-infected adults with CD4+ T-cell counts of 200 per cubic millimeter or lower. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis and the National Institutes of Health; CAMELIA ClinicalTrials.gov number, NCT01300481.).


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Antirretrovirais/administração & dosagem , Antituberculosos/uso terapêutico , Infecções por HIV/tratamento farmacológico , Tuberculose/tratamento farmacológico , Adulto , Antirretrovirais/efeitos adversos , Contagem de Linfócito CD4 , Esquema de Medicação , Feminino , Seguimentos , Infecções por HIV/complicações , Infecções por HIV/mortalidade , Humanos , Estimativa de Kaplan-Meier , Masculino , Tuberculose/complicações , Carga Viral
5.
JCI Insight ; 9(3)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329130

RESUMO

BACKGROUNDIdentifying factors that predict the timing of HIV rebound after treatment interruption will be crucial for designing and evaluating interventions for HIV remission.METHODSWe performed a broad evaluation of viral and immune factors that predict viral rebound (AIDS Clinical Trials Group A5345). Participants initiated antiretroviral therapy (ART) during chronic (N = 33) or early (N = 12) HIV infection with ≥ 2 years of suppressive ART and restarted ART if they had 2 viral loads ≥ 1,000 copies/mL after treatment interruption.RESULTSCompared with chronic-treated participants, early-treated individuals had smaller and fewer transcriptionally active HIV reservoirs. A higher percentage of HIV Gag-specific CD8+ T cell cytotoxic response was associated with lower intact proviral DNA. Predictors of HIV rebound timing differed between early- versus chronic-treated participants, as the strongest reservoir predictor of time to HIV rebound was level of residual viremia in early-treated participants and intact DNA level in chronic-treated individuals. We also identified distinct sets of pre-treatment interruption viral, immune, and inflammatory markers that differentiated participants who had rapid versus slow rebound.CONCLUSIONThe results provide an in-depth overview of the complex interplay of viral, immunologic, and inflammatory predictors of viral rebound and demonstrate that the timing of ART initiation modifies the features of rapid and slow viral rebound.TRIAL REGISTRATIONClinicalTrials.gov NCT03001128FUNDINGNIH National Institute of Allergy and Infectious Diseases, Merck.


Assuntos
Infecções por HIV , Humanos , Provírus/genética , Linfócitos T CD8-Positivos , Carga Viral , DNA
6.
AIDS ; 38(8): 1141-1152, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38489580

RESUMO

OBJECTIVE: To assess how antiretroviral therapy (ART) initiation during acute or early HIV infection (AEHI) affects the viral reservoir and host immune responses. DESIGN: Single-arm trial of ART initiation during AEHI at 30 sites in the Americas, Africa, and Asia. METHODS: HIV DNA was measured at week 48 of ART in 5 million CD4 + T cells by sensitive qPCR assays targeting HIV gag and pol . Peripheral blood mononuclear cells were stimulated with potential HIV T cell epitope peptide pools consisting of env , gag , nef, and pol peptides and stained for expression of CD3, CD4, CD8, and intracellular cytokines/chemokines. RESULTS: From 2017 to 2019, 188 participants initiated ART during Fiebig stages I ( n  = 6), II ( n  = 43), III ( n  = 56), IV ( n  = 23), and V ( n  = 60). Median age was 27 years (interquartile range 23-38), 27 (14%) participants were female, and 180 (97%) cisgender. Among 154 virally suppressed participants at week 48, 100% had detectable HIV gag or pol DNA. Participants treated during Fiebig I had the lowest HIV DNA levels ( P  < 0.001). Week 48 HIV DNA mostly did not correlate with concurrent CD4 + or CD8 + T cell HIV-specific immune responses (rho range -0.11 to +0.19, all P  > 0.025). At week 48, the magnitude, but not polyfunctionality, of HIV-specific T cell responses was moderately reduced among participants who initiated ART earliest. CONCLUSION: Earlier ART initiation during AEHI reduced but did not eliminate the persistence of HIV-infected cells in blood. These findings explain the rapid viral rebound observed after ART cessation in early-treated individuals with undetectable HIV DNA by less sensitive methods.


Assuntos
Infecções por HIV , Humanos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Feminino , Adulto , Masculino , Adulto Jovem , Antirretrovirais/uso terapêutico , Carga Viral , Linfócitos T CD4-Positivos/imunologia , DNA Viral/análise , DNA Viral/sangue , Resultado do Tratamento , Ásia , África
7.
Antimicrob Agents Chemother ; 57(3): 1524-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23274660

RESUMO

Recently, a novel variant of mecA known as mecC (mecA(LGA251)) was identified in Staphylococcus aureus isolates from both humans and animals. In this study, we identified a Staphylococcus xylosus isolate that harbors a new allotype of the mecC gene, mecC1. Whole-genome sequencing revealed that mecC1 forms part of a class E mec complex (mecI-mecR1-mecC1-blaZ) located at the orfX locus as part of a likely staphylococcal cassette chromosome mec element (SCCmec) remnant, which also contains a number of other genes present on the type XI SCCmec.


Assuntos
Proteínas de Bactérias/genética , Genoma Bacteriano , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Animais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Bovinos , Loci Gênicos , Humanos , Resistência a Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Proteínas de Ligação às Penicilinas , Isoformas de Proteínas/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Staphylococcus/efeitos dos fármacos , Fatores de Transcrição/genética
8.
J Infect Dis ; 206(4): 534-42, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22740718

RESUMO

BACKGROUND: Despite viral suppression, antiretroviral therapy (ART) does not restore CD4(+) T-cell counts in many patients infected with human immunodeficiency virus type 1 (HIV-1). METHODS: In a single-arm pilot trial involving ART recipients with suppressed plasma levels of HIV-1 RNA for at least 48 weeks and stable suboptimal CD4(+) T-cell recovery, subjects added maraviroc, a CCR5 antagonist, to their existing ART for 24 weeks. After stopping maraviroc, they were followed for an additional 24 weeks. A Wilcoxon signed-rank test was used to evaluate whether maraviroc was associated with an increase of at least 20 cells/µL in the CD4(+) T-cell count. RESULTS: A total of 34 subjects were enrolled. The median age was 50 years, and the median baseline CD4(+) T-cell count was 153 cells/µL. The median increase in CD4(+) T-cell count from baseline to week 22/24 was 12 cells/µL (90% confidence interval, 1-22). A CD4(+) T-cell count increase of at least 20 cells/µL was not detected (P = .97). Markers of immune activation and apoptosis decreased during maraviroc intensification; this decline partially reversed after discontinuing maraviroc. CONCLUSIONS: Adding maraviroc to suppressive ART for 24 weeks was not associated with an increase in CD4(+) T-cell counts of at least 20 cells/µL. Further studies of CCR5 antagonists in the dampening of immune activation associated with HIV infection are warranted. Clinical Trials Registration. NCT 00709111.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Terapia Antirretroviral de Alta Atividade/métodos , Cicloexanos/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Triazóis/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Contagem de Linfócito CD4 , Feminino , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Humanos , Masculino , Maraviroc , Pessoa de Meia-Idade , Carga Viral , Adulto Jovem
9.
Lancet Infect Dis ; 23(10): e418-e430, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37295453

RESUMO

Analytical treatment interruptions (ATIs) have become a key methodological approach to evaluate the effects of experimental HIV cure-related research interventions. During ATIs, sex partners of trial participants might be at risk of acquiring HIV. This risk raises both ethical and feasibility concerns about ATI trials. We propose a partner protection package (P3) approach to address these concerns. A P3 approach would provide guidance to investigators, sponsors, and those who are designing and implementing context-specific partner protections in HIV cure-related trials involving ATIs. The approach would also help assure institutional review boards, trial participants, and communities that ATI trials with a P3 would provide appropriate partner protections. We offer a prototype P3 framework that delineates three basic considerations for protecting participants' sex partners during ATI trials: (1) ensuring the scientific and social value of the ATI and the trial, (2) reducing the likelihood of unintended HIV transmission, and (3) ensuring prompt management of any acquired HIV infection. We outline possible ways of implementing these basic considerations.


Assuntos
Infecções por HIV , Humanos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Ensaios Clínicos como Assunto
10.
Liver Transpl ; 18(6): 716-26, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22328294

RESUMO

Hepatitis C virus (HCV) is a controversial indication for liver transplantation (LT) in human immunodeficiency virus (HIV)-infected patients because of reportedly poor outcomes. This prospective, multicenter US cohort study compared patient and graft survival for 89 HCV/HIV-coinfected patients and 2 control groups: 235 HCV-monoinfected LT controls and all US transplant recipients who were 65 years old or older. The 3-year patient and graft survival rates were 60% [95% confidence interval (CI) = 47%-71%] and 53% (95% CI = 40%-64%) for the HCV/HIV patients and 79% (95% CI = 72%-84%) and 74% (95% CI = 66%-79%) for the HCV-infected recipients (P < 0.001 for both), and HIV infection was the only factor significantly associated with reduced patient and graft survival. Among the HCV/HIV patients, older donor age [hazard ratio (HR) = 1.3 per decade], combined kidney-liver transplantation (HR = 3.8), an anti-HCV-positive donor (HR = 2.5), and a body mass index < 21 kg/m(2) (HR = 3.2) were independent predictors of graft loss. For the patients without the last 3 factors, the patient and graft survival rates were similar to those for US LT recipients. The 3-year incidence of treated acute rejection was 1.6-fold higher for the HCV/HIV patients versus the HCV patients (39% versus 24%, log rank P = 0.02), but the cumulative rates of severe HCV disease at 3 years were not significantly different (29% versus 23%, P = 0.21). In conclusion, patient and graft survival rates are lower for HCV/HIV-coinfected LT patients versus HCV-monoinfected LT patients. Importantly, the rates of treated acute rejection (but not the rates of HCV disease severity) are significantly higher for HCV/HIV-coinfected recipients versus HCV-infected recipients. Our results indicate that HCV per se is not a contraindication to LT in HIV patients, but recipient and donor selection and the management of acute rejection strongly influence outcomes.


Assuntos
Coinfecção/mortalidade , Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto , Infecções por HIV/mortalidade , Hepatite C Crônica/mortalidade , Transplante de Fígado/mortalidade , Abdome Agudo , Adulto , Feminino , Seguimentos , Humanos , Incidência , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia
11.
Can Vet J ; 53(10): 1119-22, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23543934

RESUMO

Factors associated with time to clearance of mycoplasma mastitis were studied in 18 dairy cattle herds. Most herds cleared mycoplasma mastitis within 1 month; < 50% of the herds culled diseased cows preferentially, yet culling was not associated with hastened clearance. Other known mastitis biosecurity and management practices were not associated with clearance time.


Délai de guérison de la mammite à mycoplasmes : effet des facteurs de gestion incluant l'hygiène lors de la traite et la réforme préférentielle. Les facteurs associés au délai de guérison de la mammite à mycoplasmes ont été étudiés dans 18 troupeaux laitiers. La plupart des troupeaux se débarrassaient de la mammite à mycoplasmes dans un délai d'un mois; < 50 % des troupeaux procédaient à une réforme préférentielle des vaches malades, pourtant la réforme n'a pas été associée à une guérison hâtive. Les autres pratiques de biosécurité et de gestion connues pour la mammite n'ont pas été associées au délai de guérison.(Traduit par Isabelle Vallières).


Assuntos
Antibacterianos/uso terapêutico , Indústria de Laticínios/métodos , Higiene , Mastite Bovina/prevenção & controle , Infecções por Mycoplasma/veterinária , Animais , Bovinos , Eutanásia Animal , Feminino , Mycoplasma/isolamento & purificação , Infecções por Mycoplasma/prevenção & controle , Fatores de Risco , Fatores de Tempo
12.
AIDS Res Hum Retroviruses ; 38(6): 510-517, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35323030

RESUMO

The AIDS Clinical Trials Group A5345 study (NCT03001128) included an intensively monitored antiretroviral pause (IMAP), during which participants living with HIV temporarily stopped antiretroviral treatment (ART) in an effort to identify biomarkers that could predict HIV rebound. We evaluated the potential impact of the IMAP on A5345 study participants in the United States by questioning them immediately after the IMAP and at the end of the study. We administered longitudinal sociobehavioral questionnaires to participants following the IMAP when they resumed ART and at the end of the study. We summarized descriptive data from the post-IMAP and end-of-study questionnaires. Open-ended responses were analyzed using conventional content analysis. Reactions to pausing ART involved a mixture of curiosity and satisfaction from contributing to science. All participants indicated adherence with the ART interruption. About half (9/17) of post-IMAP questionnaire respondents reported having sexual partner(s) during the IMAP, and of those, nearly all (8/9) did not find it difficult to use measures to prevent HIV transmission to partners. The majority believed that they benefited from the study, yet some had elevated anxiety following the IMAP and at the end of the study. Most (24/29) respondents who completed the end-of-study questionnaire would recommend the study to other people living with HIV. Our findings underscore the relevance of the psychosocial aspects of participating in studies that involve interruptions of ART. Understanding how participants experience this research is invaluable for informing the design of future research aimed at sustained ART-free virologic suppression.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Antirretrovirais/uso terapêutico , Biomarcadores , Infecções por HIV/tratamento farmacológico , Humanos , Parceiros Sexuais , Estados Unidos
13.
J Clin Invest ; 132(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34762600

RESUMO

Early initiation of antiretroviral therapy (ART) in acute HIV infection (AHI) is effective at limiting seeding of the HIV viral reservoir, but little is known about how the resultant decreased antigen load affects long-term Ab development after ART. We report here that Env-specific plasma antibody (Ab) levels and Ab-dependent cellular cytotoxicity (ADCC) increased during the first 24 weeks of ART and correlated with Ab levels persisting after 48 weeks of ART. Participants treated in AHI stage 1 had lower Env-specific Ab levels and ADCC activity on ART than did those treated later. Importantly, participants who initiated ART after peak viremia in AHI developed elevated cross-clade ADCC responses that were detectable 1 year after ART initiation, even though clinically undetectable viremia was reached by 24 weeks. These data suggest that there is more germinal center (GC) activity in the later stages of AHI and that Ab development continues in the absence of detectable viremia during the first year of suppressive ART. The development of therapeutic interventions that can enhance earlier development of GCs in AHI and Abs after ART initiation could provide important protection against the viral reservoir that is seeded in individuals treated early in the disease.


Assuntos
Antirretrovirais/administração & dosagem , Anticorpos Anti-HIV/sangue , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , HIV-1/metabolismo , Doença Aguda , Adulto , Linhagem Celular , Feminino , Humanos , Masculino , Viremia/sangue , Viremia/tratamento farmacológico
14.
J Bacteriol ; 193(8): 1854-62, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21317317

RESUMO

Cocolonization of human mucosal surfaces causes frequent encounters between various staphylococcal species, creating opportunities for the horizontal acquisition of mobile genetic elements. The majority of Staphylococcus aureus toxins and virulence factors are encoded on S. aureus pathogenicity islands (SaPIs). Horizontal movement of SaPIs between S. aureus strains plays a role in the evolution of virulent clinical isolates. Although there have been reports of the production of toxic shock syndrome toxin 1 (TSST-1), enterotoxin, and other superantigens by coagulase-negative staphylococci, no associated pathogenicity islands have been found in the genome of Staphylococcus epidermidis, a generally less virulent relative of S. aureus. We show here the first evidence of a composite S. epidermidis pathogenicity island (SePI), the product of multiple insertions in the genome of a clinical isolate. The taxonomic placement of S. epidermidis strain FRI909 was confirmed by a number of biochemical tests and multilocus sequence typing. The genome sequence of this strain was analyzed for other unique gene clusters and their locations. This pathogenicity island encodes and expresses staphylococcal enterotoxin C3 (SEC3) and staphylococcal enterotoxin-like toxin L (SElL), as confirmed by quantitative reverse transcription-PCR (qRT-PCR) and immunoblotting. We present here an initial characterization of this novel pathogenicity island, and we establish that it is stable, expresses enterotoxins, and is not obviously transmissible by phage transduction. We also describe the genome sequence, excision, replication, and packaging of a novel bacteriophage in S. epidermidis FRI909, as well as attempts to mobilize the SePI element by this phage.


Assuntos
Proteínas de Bactérias/genética , Enterotoxinas/genética , Ilhas Genômicas , Staphylococcus epidermidis/genética , Fatores de Virulência/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/química , DNA Bacteriano/genética , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Mutagênese Insercional , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/classificação , Staphylococcus epidermidis/isolamento & purificação , Staphylococcus epidermidis/patogenicidade
15.
Blood ; 113(25): 6304-14, 2009 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-19380868

RESUMO

Interleukin 7 (IL-7) is a common gamma chain receptor cytokine implicated in thymopoiesis and in peripheral expansion and survival of T lymphocytes. The safety and activity of recombinant human IL-7 (rhIL-7) administration were therefore examined in HIV-infected persons. In this prospective randomized placebo-controlled study, a single subcutaneous dose of rhIL-7 was well tolerated with biologic activity demonstrable at 3 microg/kg and a maximum tolerated dose of 30 microg/kg. Injection site reactions and transient elevations of liver function tests were the most notable side effects. Transient increases in plasma HIV-RNA levels were observed in 6 of 11 IL-7-treated patients. Recombinant hIL-7 induced CD4 and CD8 T cells to enter cell cycle; cell-cycle entry was also confirmed in antigen-specific CD8 T cells. Administration of rhIL-7 led to transient down-regulation of the IL-7 receptor alpha chain (CD127) in both CD4(+) and CD8(+) T cells. Single-dose rhIL-7 increased the numbers of circulating CD4(+) and CD8(+) T cells, predominantly of central memory phenotype. The frequency of CD4(+) T cells with a regulatory T-cell phenotype (CD25(high) CD127(low)) did not change after rhIL-7 administration. Thus, rhIL-7 has a biologic and toxicity profile suggesting a potential for therapeutic trials in HIV infection and other settings of lymphopenia. This clinical trial has been registered at http://www.clinicaltrials.gov under NCT0099671.


Assuntos
Infecções por HIV/tratamento farmacológico , HIV-1 , Interleucina-7/uso terapêutico , Subpopulações de Linfócitos T/efeitos dos fármacos , Adulto , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Ciclo Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Regulação para Baixo/efeitos dos fármacos , Feminino , Infecções por HIV/imunologia , Humanos , Memória Imunológica/efeitos dos fármacos , Interleucina-7/administração & dosagem , Interleucina-7/efeitos adversos , Interleucina-7/sangue , Interleucina-7/farmacologia , Subunidade alfa de Receptor de Interleucina-7/biossíntese , Subunidade alfa de Receptor de Interleucina-7/genética , Contagem de Linfócitos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/sangue , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Carga Viral
16.
Clin Trials ; 8(6): 727-35, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22024105

RESUMO

BACKGROUND: Historically, four divisions of the National Institute of Allergy and Infectious Diseases (NIAID) that manage clinical trials and oversee data and safety monitoring have operated fairly autonomously with respect to their approaches to Data and Safety Monitoring Board (DSMB) operations. We recognized the need for a revised policy on DSMB operations in an effort to encourage greater harmonization of procedures across the four divisions. PURPOSE: The purpose of this article is to describe the considerations that motivated the development of the new policy, summarize current DSMB policies and ongoing harmonization efforts across the four divisions, and offer some recommendations for DSMB operations in the hope that other organizations may benefit from our experience. METHODS: From 2005 to 2009, a working group undertook a review of DSMB responsibilities, policies, and operations. We analyzed and summarized the final policy document that the working group produced, gathered data describing current DSMB activities, and developed a tabular, cross-sectional overview highlighting how divisions are harmonizing their DSMB operations. RESULTS: In 2010, there were 44 DSMBs in NIAID monitoring 169 protocols, and those DSMBs conducted 209 reviews of the protocols. Review and analysis of DSMB practices across the four divisions have led to recommendations for efficient and successful DSMB operations: adopt an inclusive approach, whereby the trial investigators assist in the process of forming and utilizing DSMBs; structures other than DSMBs can often provide many of the features of DSMBs but with greater flexibility in membership, access to interim data, and scheduling; the trial protocol should specify what safety and other concerns should trigger a DSMB review and what data should be included in prespecified reviews; present data in thoughtful and user-friendly ways that answer specific questions; allow sufficient time to plan for working with the DSMB. LIMITATIONS: We recognize that NIAID's specific circumstances and DSMB policy may not apply to the operation of DSMBs in every organization. Nevertheless, we believe that useful lessons can be learned from our experiences and efforts toward harmonization. CONCLUSIONS: Homogeneity in DSMB operations and management has appeal as a matter of organizational policy and efficiency. Some limited flexibility, as long as it honors fundamental principles of independence, confidentiality of interim trial results, and clear lines of reporting and approval, may be appropriate on occasion. NIAID's 2009 institute-level policy established a collective understanding of the important contribution that DSMBs make to the responsible conduct of clinical trials. Thinking will continue to evolve, leading to further policy refinements and the continued assurance of patient safety in our clinical trials.


Assuntos
Ensaios Clínicos como Assunto , Segurança Computacional , National Institute of Allergy and Infectious Diseases (U.S.) , Política Organizacional , Gestão da Segurança/organização & administração , Comitês de Monitoramento de Dados de Ensaios Clínicos , Eficiência Organizacional , Humanos , Formulação de Políticas , Estados Unidos
17.
PLoS One ; 16(3): e0243688, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33720932

RESUMO

Staphylococcus chromogenes is a common skin commensal in cattle and has been identified as a frequent cause of bovine mastitis and intramammary infections. We have developed a seven locus Multilocus Sequence Typing (MLST) scheme for typing S. chromogenes. Sequence-based typing systems, such as MLST, have application in studies of genetic diversity, population structure, and epidemiology, including studies of strain variation as a factor in pathogenicity or host adaptation. The S. chromogenes scheme was tested on 120 isolates collected from three geographic locations, Vermont and Washington State in the United States and Belgium. A total of 46 sequence types (STs) were identified with most of the STs being location specific. The utility of the typing scheme is indicated by a discrimination power of 95.6% for all isolates and greater than 90% for isolates from each of the three locations. Phylogenetic analysis placed 39 of the 46 STs into single core group consistent with a common genetic lineage; the STs in this group differ by less than 0.5% at the nucleotide sequence level. Most of the diversification in this lineage group can be attributed to mutation; recombination plays a limited role. This lineage group includes two clusters of single nucleotide variants in starburst configurations indicative of recent clonal expansion; nearly 50% of the isolates sampled in this study are in these two clusters. The remaining seven STs were set apart from the core group by having alleles with highly variable sequences at one or more loci. Recombination had a higher impact than mutation in the diversification of these outlier STs. Alleles with hypervariable sequences were detected at five of the seven loci used in the MLST scheme; the average sequence distances between the hypervariable alleles and the common core alleles ranged from 12 to 34 nucleotides. The extent of these sequence differences suggests the hypervariable alleles may be remnants of an ancestral genotype.


Assuntos
Variação Genética , Staphylococcus/genética , Alelos , Animais , Bovinos , Genótipo , Tipagem de Sequências Multilocus , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Recombinação Genética , Staphylococcus/classificação , Staphylococcus/crescimento & desenvolvimento , Suínos
18.
AIDS Res Hum Retroviruses ; 37(6): 489-501, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33472545

RESUMO

The AIDS Clinical Trials Group (ACTG) A5345 study included an intensively monitored antiretroviral pause (IMAP), during which a cohort of participants temporarily stopped antiretroviral treatment during chronic HIV infection. We surveyed participant perceptions and understanding of A5345 using a cross-sectional sociobehavioral questionnaire. Participants completed the baseline questionnaire either before or after initiating the study's IMAP. Questionnaire responses were linked to existing demographic data. Quantitative responses were analyzed overall and stratified by IMAP status. Open-ended responses were analyzed using conventional content analysis. Thirty-two participants completed the baseline sociobehavioral questionnaire. Half (n = 16) completed it before (i.e., pre-IMAP initiation group) and half (n = 16) after IMAP initiation (i.e., post-IMAP initiation group). Eight pre-IMAP initiation respondents (50%) and 11 post-IMAP respondents (69%) responded "yes" when asked if they perceived any direct benefits from participating in A5345. Perceived societal-level benefits included furthering HIV cure-related research and helping the HIV community. Perceived personal-level benefits included the opportunity to learn about the body's response to IMAP and financial compensation. The majority of respondents-13 from each group (81% of each)-reported risks from participation, for example, viral load becoming detectable. A5345 participants perceived both societal- and personal-level benefits of study participation. While the majority of survey respondents perceived participatory risks, nearly one in five did not. Key messages pertaining to study-related risks and benefits may need to be clarified or reiterated periodically throughout follow-up in HIV cure-related studies with IMAPs. Clinical Trail Registration Number: NCT03001128.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Biomarcadores , Estudos Transversais , Infecções por HIV/tratamento farmacológico , Humanos , Carga Viral
19.
J Virol ; 83(19): 9731-42, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19605490

RESUMO

In most human immunodeficiency virus type 1 (HIV-1)-infected individuals who achieve viral loads of <50 copies/ml during highly active antiretroviral therapy (HAART), low levels of plasma virus remain detectable for years by ultrasensitive methods. The relative contributions of ongoing virus replication and virus production from HIV-1 reservoirs to persistent low-level viremia during HAART remain controversial. HIV-1 vaccination of HAART-treated individuals provides a model for examining low-level viremia, as immunizations may facilitate virus replication and sequence evolution. In a phase 1 trial of modified vaccinia virus Ankara/fowlpox virus-based HIV-1 vaccines in 20 HIV-infected young adults receiving HAART, we assessed the prevalence of low-level viremia and sequence evolution, using ultrasensitive viral load (<6.5 copies/ml) and genotyping (five-copy sensitivity) assays. Viral evolution, consisting of new drug resistance mutations and novel amino acid changes within a relevant HLA-restricted allele (e.g., methionine, isoleucine, glutamine, or arginine for leucine at position 205 of RT), was found in 1 and 3 of 20 subjects, respectively. Sequence evolution was significantly correlated with levels of viremia of between 6.5 and <50 copies/ml (P = 0.03) and was more likely to occur within epitopes presented by relevant HLA alleles (P < 0.001). These findings suggest that ongoing virus replication contributes to low-level viremia in patients on HAART and that this ongoing replication is subject to CD8(+) T-cell selective pressures.


Assuntos
Antirretrovirais/farmacologia , Infecções por HIV/virologia , HIV-1/metabolismo , Poxviridae/genética , Adulto , Terapia Antirretroviral de Alta Atividade , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Estudos de Coortes , Feminino , Genótipo , Infecções por HIV/tratamento farmacológico , Humanos , Imunização , Masculino , Análise de Sequência de DNA
20.
AIDS Res Ther ; 7: 30, 2010 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-20687947

RESUMO

BACKGROUND: Effective antiretroviral therapy reduces HIV-1 RNA levels, improves CD4 T-cell counts, and lowers the risk of opportunistic infections and malignancies. Interleukin-2 (IL-2) has been shown to increase CD4 T-cell numbers mainly by expanding CD4 cells and by prolonging their half-lives. HIV-infected patients previously enrolled into A328 had been randomized to antiretroviral therapy (ART) alone or ART followed by IL-2. In A5051, 53 patients from A328 who had previously received IL-2 were allowed to continue IL-2 for an additional 80 weeks; 27 patients who had received ART alone received IL-2 for 80 weeks. RESULTS: The patients previously receiving IL-2 continued to have elevated CD4 levels with extended use of IL-2. The prior ART-alone recipients had increases in CD4 levels to comparable levels as the prior IL-2 recipients (median 804 versus 847 cells/mm3 at week 72; 60% versus 9% had >50% increase in A5051 to week 72, p < 0.001). Those who had previously received IL-2 required fewer IL-2 cycles to maintain their CD4 T-cell counts compared to those newly initiating IL-2. The treatments were well tolerated with no significant differences in toxicity or discontinuations between those newly versus previously receiving IL-2. There were few clinical events observed. CONCLUSIONS: Although sustained CD4 T-cell count increases were seen with IL-2 administration as in other studies, the absence of clinical benefit in two recent randomized trials has demonstrated no apparent role for IL-2 as a therapy in HIV disease. TRIAL REGISTRATION: A5051 ClinicalTrials.gov Identifier: NCT00000923.

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