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1.
J Infect Dis ; 226(8): 1412-1417, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-35921539

RESUMO

We evaluated the performance of nasal and nasopharyngeal Standard Q COVID-19 [coronavirus disease 2019] Ag tests (SD Biosensor) and the Panbio COVID-19 Ag Rapid Test Device (nasal; Abbott) against the Abbott RealTime severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assay during the Omicron (clades 21M, 21K, and 21L) wave in South Africa. Overall, all evaluated tests performed well, with high sensitivity (range, 77.78%-81.42%) and excellent specificity values (>99%). The sensitivity of rapid antigen tests increased above 90% in samples with cycle threshold <20, and all 3 tests performed best within the first week after symptom onset.


Assuntos
COVID-19 , SARS-CoV-2 , Antígenos Virais , COVID-19/diagnóstico , Teste para COVID-19 , Humanos , Sensibilidade e Especificidade , África do Sul
2.
J Infect Dis ; 226(3): 510-520, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-35134995

RESUMO

BACKGROUND: Effective, long-acting prevention approaches are needed to reduce human immunodeficiency virus (HIV) incidence. We evaluated the safety and pharmacokinetics of VRC07-523LS and PGT121 administered subcutaneously alone and in combination as passive immunization for young women in South Africa. METHODS: CAPRISA 012A was a randomized, double-blinded, placebo-controlled, dose-escalation phase 1 trial. We enrolled 45 HIV-negative women into 9 groups and assessed safety, tolerability, pharmacokinetics, neutralization activity, and antidrug antibody levels. Pharmacokinetic modeling was conducted to predict steady-state concentrations for 12- and 24-weekly dosing intervals. RESULTS: VRC07-523LS and PGT121, administered subcutaneously, were safe and well tolerated. Most common reactogenicity events were injection site tenderness and headaches. Nine product-related adverse events were mild and transient. Median VRC07-523LS concentrations after 20 mg/kg doses were 9.65 µg/mL and 3.86 µg/mL at 16 and 24 weeks. The median week 8 concentration after the 10 mg/kg PGT121 dose was 8.26 µg/mL. Modeling of PGT121 at 20 mg/kg showed median concentrations of 1.37 µg/mL and 0.22 µg/mL at 16 and 24 weeks. Half-lives of VRC07-523LS and PGT121 were 29 and 20 days. Both antibodies retained neutralizing activity postadministration and no antidrug antibodies were detected. CONCLUSIONS: Subcutaneous administration of VRC07-523LS in combination with optimized versions of PGT121 or other antibodies should be further assessed for HIV prevention.


Assuntos
Antineoplásicos Imunológicos , Infecções por HIV , Anticorpos Monoclonais , Anticorpos Neutralizantes , Feminino , HIV , Anticorpos Anti-HIV , Humanos , Imunização Passiva
3.
Afr J AIDS Res ; 21(4): 317-329, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36538540

RESUMO

Globally, COVID-19 has impacted lives and livelihoods. Women living with HIV and/or at high risk of acquiring HIV are socially and economically vulnerable. Less is known of the impact of COVID-19 public health responses on women from key and vulnerable populations. The purpose of this cross-sectional survey conducted in four South African provinces with a high burden of HIV and COVID-19 from September to November 2021 was to advance understanding of the socio-economic and health care access impact of COVID-19 on women living with HIV or at high risk of acquiring HIV. A total of 2 812 women >15 years old completed the survey. Approximately 31% reported a decrease in income since the start of the pandemic, and 43% an increase in food insecurity. Among those accessing health services, 37% and 36% reported that COVID-19 had impacted their access to HIV and family planning services respectively. Economic and service disruptions were enhanced by living in informal housing, urbanisation and being in the Western Cape. Food insecurity was increased by being a migrant, having fewer people contributing to the household, having children and experience of gender-based violence. Family planning service disruptions were greater for sex workers and having fewer people contributing to the household. These differentiated impacts on income, food security, access to HIV and family planning services were mediated by age, housing, social cohesion, employment and household income, highlighting the need for improved structural and systemic interventions to reduce the vulnerability of women living with HIV or at high risk of acquiring HIV.


Assuntos
COVID-19 , Infecções por HIV , Criança , Humanos , Feminino , Adolescente , COVID-19/epidemiologia , África do Sul/epidemiologia , Infecções por HIV/epidemiologia , Saúde Pública , Estudos Transversais , Serviços de Saúde , Segurança Alimentar , Abastecimento de Alimentos
4.
Clin Infect Dis ; 73(8): 1528-1531, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34181706

RESUMO

Understanding what shapes the latent human immunodeficiency virus type 1 (HIV-1) reservoir is critical for developing strategies for cure. We measured frequency of persistent HIV-1 infection after 5 years of suppressive antiretroviral therapy initiated during chronic infection. Pretreatment CD8+ T-cell activation, nadir CD4 count, and CD4:CD8 ratio predicted reservoir size.


Assuntos
Infecções por HIV , HIV-1 , Antirretrovirais/uso terapêutico , Linfócitos T CD4-Positivos , Infecções por HIV/tratamento farmacológico , Humanos , Carga Viral , Latência Viral , Replicação Viral
6.
BMC Med ; 17(1): 84, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31030670

RESUMO

BACKGROUND: It is critically important to conduct research on stigmatized conditions, to include marginalized groups that experience stigma, and to develop interventions to reduce stigma. However, such research is ethically challenging. Though superficial reference is frequently made to these widely acknowledged challenges, few publications have focused on ethical issues in research on stigmatized groups or conditions. In fact, a brief literature review found only two such publications. MAIN TEXT: At a recent Science of Stigma Reduction workshop comprising 60 stigma researchers from the USA and low and middle-income countries, the need for more robust and critical discussion of the ethics of the research was highlighted. In this paper we describe, illustrate through cases, and critically examine key ethical challenges that are more likely to arise because a research study focuses on health-related stigma or involves stigmatized groups or conditions. We examine the ethics of this research from two perspectives. First, through the lens of overprotection, where we discuss how the perception of stigma can impede ethical research, disrespect research participants, and narrow the research questions. Second, through the lens of research risks, where we consider how research with stigmatized populations can unintentionally result in harms. Research-related harms to participants include potential breaches of confidentiality and the exacerbation of stigma. Potential harms also extend to third parties, including families and populations who may be affected by the dissemination of research results. CONCLUSIONS: Research with stigmatized populations and on stigmatized conditions should not be impeded by unnecessary or inappropriate protective measures. Nevertheless, it may entail different and greater risks than other health research. Investigators and research ethics committees must be particularly attentive to these risks and how to manage them.


Assuntos
Comitês de Ética em Pesquisa/ética , Saúde Global/ética , Estigma Social , Humanos , Projetos de Pesquisa
8.
BMC Public Health ; 19(1): 53, 2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-30634943

RESUMO

BACKGROUND: Suboptimal HIV testing rates through available testing approaches such as HIV counselling and testing have directed research efforts toward recognizing the potential of HIV self-testing as an additional testing method. However, HIV self-testing is not readily available within HIV testing facilities and data on how HIV self-testing and HIV counselling and testing will co-exist within HIV testing facilities is limited. Therefore, this study sought to fill this knowledge gap. METHODS: Forty consenting adults were exposed to HIV counselling and testing and HIV self-testing using a cross-over study design between February 2016 and February 2017 resulting in 80 (20,20) interviews. Participants were randomly exposed to HIV counselling and testing first, followed by self-testing, or HIV self-testing first, followed by counselling and testing. In-depth interviews were conducted at baseline, and after each testing exposure, using a semi-structured interview guide. Interviews were transcribed and translated prior to doing the framework analysis. RESULTS: Support through counselling played a central role in the HIV testing process for some participants who desired support or were not confident to perform unsupervised HIV self-testing. The complementary relationship between HIV self-testing and HIV counselling and testing requires a combination of benefits such as availability of counselling, confidence, convenience and confidentiality (4 Cs) derived from HIV self-testing and HIV counselling and testing. Implementation of the 4 Cs will depend on the availability of unsupervised HIV self-testing and/or supervised self-testing with support from HIV counselling and testing. CONCLUSIONS: As treatment and prevention efforts expand, the reasons for and frequency of testing is changing and there is a need to develop differentiated models for providing HIV testing services to meet client's needs. HIV self-testing is an important addition to enhance HIV testing efforts and should be offered in combination with HCT.


Assuntos
Aconselhamento , Infecções por HIV/diagnóstico , Autocuidado , Adulto , Estudos Cross-Over , Feminino , HIV , Infecções por HIV/virologia , Humanos , Masculino , População Rural , África do Sul , População Urbana
9.
Infect Dis Obstet Gynecol ; 2019: 7808179, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31186607

RESUMO

Background: High rates of bacterial vaginosis (BV) have been described in nonpregnant South African women. Studies of BV in South African pregnant women are sparse. Diagnosis and prompt treatment of BV in pregnancy are expected to have a positive impact on pregnancy outcomes and HIV prevention. This study was undertaken to determine the prevalence of BV in pregnant women in a high HIV burden periurban setting in KwaZulu-Natal and explore how to enhance BV diagnosis in this setting where syndromic management of sexually transmitted diseases is the standard of care. Methods: In this cross-sectional study, consenting HIV uninfected pregnant women were examined for abnormal vaginal discharge; nurses determined the vaginal pH and collected a vaginal swab for Gram-stain and Nugent scoring. Findings: Among 750 HIV uninfected pregnant women, 280 (37.3%; 95%CI 33.9-40.9) tested positive for BV. Using a vaginal pH > 4.4, 65% of women with BV were correctly identified, while an abnormal vaginal discharge correctly identified a significantly lower proportion (52.9%) of women with BV (p=0.005). The sensitivity, specificity, and positive and negative predictive values of vaginal pH testing were 65.9% (95%CI 60.0 - 71.5%), 61.4% (95%CI 56.8 - 65.9%), and 50.1% and 75.4%, respectively. The 20-24 year-old pregnant women were twice more likely to test positive for BV than the adolescent pregnant women (43.6% vs 21.1%) (p = 0.037) and BV was not associated with the duration of a sexual relationship, frequency of unprotected sex during pregnancy, number of lifetime sex partners, or the partner's age. Conclusion: There is a high burden of primarily asymptomatic BV in HIV uninfected pregnant women in this periurban setting. Both the sensitivity and specificity of vaginal pH testing are superior to the symptomatic diagnosis of BV but not good enough to be used as a screening tool.


Assuntos
Complicações Infecciosas na Gravidez/epidemiologia , Vaginose Bacteriana/epidemiologia , Adolescente , Adulto , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Prevalência , Vaginose Bacteriana/diagnóstico , Adulto Jovem
10.
AIDS Behav ; 22(3): 1018-1024, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28224322

RESUMO

WHO guidelines recommend immediate initiation of antiretroviral therapy (ART) for all individuals at HIV diagnosis regardless of CD4 count, but concerns remain about potential low uptake or poor adherence among healthy patients with high CD4 counts, especially in resource-limited settings. This study assessed the acceptability of earlier treatment among HIV-positive South African women, median age at enrollment 25 (IQR 22-30), in a 10 year prospective cohort study by (i) describing temporal CD4 count trends at initiation in relation to WHO guidance, (ii) virological suppression rates post-ART initiation at different CD4 count thresholds, and (iii) administration of a standardized questionnaire. 158/232 (68.1%) participants initiated ART between 2006 and 2015. Mean CD4 count at initiation was 217 cells/µl (range 135-372) before 2010, and increased to 531 cells/µl (range 272-1095) by 2015 (p < 0.001). Median viral load at ART initiation decreased over this period from 5.2 (IQR 4.6-5.6) to 4.1 (IQR 3.4-4.6) log copies/ml (p = 0.004). Virological suppression rates at 3, 6, 12 and 18 months were consistently above 85% with no statistically significant differences for participants starting ART at different CD4 count thresholds. A questionnaire assessing uptake of early ART amongst ART-naïve women, median age 28 (IQR 24-33), revealed that 40/51 (78.4%) were willing to start ART at CD4 ≥500. Of those unwilling, 6/11 (54.5%) started ART within 6 months of questionnaire administration. Temporal increases in CD4 counts, comparable virological suppression rates, and positive patient perceptions confirm high acceptability of earlier ART initiation for the majority of patients.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , População Negra/psicologia , Infecções por HIV/tratamento farmacológico , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Prevenção Secundária , Carga Viral/efeitos dos fármacos , Adulto , População Negra/estatística & dados numéricos , Contagem de Linfócito CD4 , Estudos de Coortes , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Humanos , Masculino , Manejo da Dor , Aceitação pelo Paciente de Cuidados de Saúde/etnologia , Estudos Prospectivos , África do Sul/epidemiologia , Inquéritos e Questionários , Adulto Jovem
12.
J Immunol ; 195(5): 2273-2281, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26195814

RESUMO

Antiretroviral therapy (ART) induces rapid suppression of viral replication and a progressive replenishment of CD4(+) T cells in HIV-infected individuals. However, the effect of ART on restoring pre-existing memory CD4(+) T cells specific for common copathogens is still unclear. To better understand the dynamics of Ag-specific CD4(+) T cells during ART, we assessed the frequency, functional capacity, and memory profile of CD4(+) T cells specific for Mycobacterium tuberculosis and CMV in 15 HIV-infected individuals before and 1 y after ART initiation. After ART initiation, the frequency of M. tuberculosis-specific CD4(+) T cells showed little change, whereas CMV-specific CD4(+) T cells were significantly lower (p = 0.003). There was no difference in the polyfunctional or memory profile of Ag-specific CD4(+) T cells before and after ART. The replenishment of Ag-specific CD4(+) T cells correlated with the memory differentiation profile of these cells prior to ART. Pathogen-specific CD4(+) T cells exhibiting a late differentiated profile (CD45RO(+)CD27(-)) had a lower capacity to replenish (p = 0.019; r = -0.5) compared with cells with an early differentiated profile (CD45RO(+)CD27(+); p = 0.04; r = 0.45). In conclusion, restoration of copathogen-specific memory CD4(+) T cells during treated HIV infection is related to their memory phenotype, in which early differentiated cells (such as most M. tuberculosis-specific cells) have a higher replenishment capacity compared with late differentiated cells (such as most CMV-specific cells). These data identify an important, hitherto unrecognized, factor that may limit restoration of copathogen immunity in HIV-infected individuals on ART.


Assuntos
Antirretrovirais/imunologia , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , Memória Imunológica/imunologia , Antirretrovirais/farmacologia , Contagem de Linfócito CD4 , Relação CD4-CD8 , Linfócitos T CD4-Positivos/efeitos dos fármacos , Células Cultivadas , Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Citometria de Fluxo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Humanos , Memória Imunológica/efeitos dos fármacos , Imunofenotipagem , Antígenos Comuns de Leucócito/imunologia , Antígenos Comuns de Leucócito/metabolismo , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/fisiologia , Resultado do Tratamento , Tuberculose/imunologia , Tuberculose/microbiologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Carga Viral/efeitos dos fármacos
13.
Curr HIV/AIDS Rep ; 13(3): 158-69, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27137200

RESUMO

The HIV pandemic has disproportionately impacted sub-Saharan Africa and Southern Africa in particular. The concurrent presence of overlapping epidemic drivers likely underpins how and why the HIV epidemic is so explosive in this region, with implications for understanding approaches to reduce transmission. In this review, we discuss the relative contribution and interaction between epidemic drivers in the Southern African context, including factors both distally and proximally associated with the likelihood and degree of exposure to HIV and factors that increase the probability of transmission when exposure occurs. In particular, we focus on young women as a key population in need of HIV prevention and highlight factors that increase their risk on several levels.


Assuntos
Infecções por HIV/epidemiologia , Infecções por HIV/transmissão , Educação em Saúde/normas , Comportamento Sexual/psicologia , África Subsaariana/epidemiologia , África Austral/epidemiologia , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Prevalência , Fatores de Risco , Comportamento Social , Fatores Socioeconômicos , Saúde da Mulher
14.
AIDS Behav ; 20(11): 2682-2691, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26945585

RESUMO

CAPRISA 008, an open-label extension study of tenofovir gel with coitally-related dosing, provided an opportunity to explore the relationship between product adherence and gender dynamics in a context where women knew they were receiving an active product with evidence of HIV prevention effectiveness. Interviews with 63 CAPRISA 008 participants and 13 male partners in KwaZulu-Natal, South Africa, highlighted that the process of negotiating gel use was determined in part by relationship dynamics including the duration of the relationship, the living situation, an evaluation of the relationship (e.g., partner intimacy and relationship expectations) and culturally-defined steps for formalizing the relationship. While disclosure facilitated adherence for many, others reported using the gel effectively with no disclosure, and in some situations disclosure was a barrier to adherence. Women should be supported in their choice about what to disclose and have opportunity to use this and similar products without their partners' knowledge or acquiescence.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Identidade de Gênero , Infecções por HIV/prevenção & controle , Infecções por HIV/psicologia , Relações Interpessoais , Adesão à Medicação/psicologia , Profilaxia Pré-Exposição , Autorrevelação , Tenofovir/administração & dosagem , Adolescente , Adulto , Feminino , Géis , Humanos , Masculino , Negociação , Fatores Sexuais , África do Sul
15.
J Infect Dis ; 212(5): 754-9, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25712973

RESUMO

The CAPRISA 004 preexposure prophylaxis (PrEP) randomized trial demonstrated that women who used a vaginal gel containing the antiretroviral drug tenofovir (TFV) had a 39% lower risk of acquiring human immunodeficiency virus (HIV). It is not known whether topical TFV alters the antibody response to breakthrough HIV infection. In this study, antibody maturation was evaluated using 3 serologic assays: the BED capture enzyme immunoassay (CEIA), the Bio-Plex (Luminex) assay, and the Bio-Rad avidity assay. Tests were performed using serum samples collected 3, 6, 9, 12, 24, 36, 48, and >48 months after seroconversion from 95 women in the CAPRISA 004 trial (35 in the TFV gel arm and 60 in the placebo arm). For the BED CEIA and Luminex assay, linear mixed effects models were used to examine test results by study arm. Cox proportional hazard analysis was used to examine time to avidity cutoff. Anti-HIV antibody titers did not differ between study arms. Women assigned to TFV gel demonstrated slower antibody avidity maturation, as determined by the Bio-Rad (P = .04) and gp120 Bio-Plex (P = .028) assays. Women who were assigned to receive topical TFV but became infected had slower antibody avidity maturation, with potential implications for diagnosis and antibody-based incidence assays as access to antiretroviral therapy-based PrEP is increased.


Assuntos
Antirretrovirais/uso terapêutico , Afinidade de Anticorpos , Anticorpos Anti-HIV/sangue , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV/imunologia , Profilaxia Pré-Exposição , Adenina/análogos & derivados , Adenina/uso terapêutico , Adulto , Estudos de Coortes , Feminino , Humanos , Imunoensaio , Organofosfonatos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Tenofovir , Fatores de Tempo , Adulto Jovem
16.
PLoS Med ; 12(1): e1001778, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25612136

RESUMO

BACKGROUND: Observational studies of a putative association between hormonal contraception (HC) and HIV acquisition have produced conflicting results. We conducted an individual participant data (IPD) meta-analysis of studies from sub-Saharan Africa to compare the incidence of HIV infection in women using combined oral contraceptives (COCs) or the injectable progestins depot-medroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) with women not using HC. METHODS AND FINDINGS: Eligible studies measured HC exposure and incident HIV infection prospectively using standardized measures, enrolled women aged 15-49 y, recorded ≥15 incident HIV infections, and measured prespecified covariates. Our primary analysis estimated the adjusted hazard ratio (aHR) using two-stage random effects meta-analysis, controlling for region, marital status, age, number of sex partners, and condom use. We included 18 studies, including 37,124 women (43,613 woman-years) and 1,830 incident HIV infections. Relative to no HC use, the aHR for HIV acquisition was 1.50 (95% CI 1.24-1.83) for DMPA use, 1.24 (95% CI 0.84-1.82) for NET-EN use, and 1.03 (95% CI 0.88-1.20) for COC use. Between-study heterogeneity was mild (I(2) < 50%). DMPA use was associated with increased HIV acquisition compared with COC use (aHR 1.43, 95% CI 1.23-1.67) and NET-EN use (aHR 1.32, 95% CI 1.08-1.61). Effect estimates were attenuated for studies at lower risk of methodological bias (compared with no HC use, aHR for DMPA use 1.22, 95% CI 0.99-1.50; for NET-EN use 0.67, 95% CI 0.47-0.96; and for COC use 0.91, 95% CI 0.73-1.41) compared to those at higher risk of bias (p(interaction) = 0.003). Neither age nor herpes simplex virus type 2 infection status modified the HC-HIV relationship. CONCLUSIONS: This IPD meta-analysis found no evidence that COC or NET-EN use increases women's risk of HIV but adds to the evidence that DMPA may increase HIV risk, underscoring the need for additional safe and effective contraceptive options for women at high HIV risk. A randomized controlled trial would provide more definitive evidence about the effects of hormonal contraception, particularly DMPA, on HIV risk.


Assuntos
Anticoncepcionais Femininos/administração & dosagem , Infecções por HIV/epidemiologia , Acetato de Medroxiprogesterona/administração & dosagem , Noretindrona/análogos & derivados , Adolescente , Adulto , África Subsaariana/epidemiologia , Anticoncepcionais Femininos/efeitos adversos , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Humanos , Incidência , Acetato de Medroxiprogesterona/efeitos adversos , Pessoa de Meia-Idade , Noretindrona/administração & dosagem , Noretindrona/efeitos adversos , Fatores de Risco
17.
Retrovirology ; 12: 54, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26105197

RESUMO

BACKGROUND: The integrin α4ß7 mediates the trafficking of immune cells to the gut associated lymphoid tissue (GALT) and is an attachment factor for the HIV gp120 envelope glycoprotein. We developed a viral replication inhibition assay to more clearly evaluate the role of α4ß7 in HIV infection and the contribution of viral and host factors. RESULTS: Replication of 60 HIV-1 subtype C viruses collected over time from 11 individuals in the CAPRISA cohort were partially inhibited by antibodies targeting α4ß7. However, dependence on α4ß7 for replication varied substantially among viral isolates from different individuals as well as over time in some individuals. Among 8 transmitted/founder (T/F) viruses, α4ß7 reactivity was highest for viruses having P/SDI/V tri-peptide binding motifs. Mutation of T/F viruses that had LDI/L motifs to P/SDI/V resulted in greater α4ß7 reactivity, whereas mutating P/SDI/V to LDI/L motifs was associated with reduced α4ß7 binding. P/SDI/V motifs were more common among South African HIV subtype C viruses (35%) compared to subtype C viruses from other regions of Africa (<8%) and to other subtypes, due in part to a founder effect. In addition, individuals with bacterial vaginosis (BV) and who had higher concentrations of IL-7, IL-8 and IL-1α in the genital tract had T/F viruses with higher α4ß7 dependence for replication, suggesting that viruses with P/SDI/V motifs may be preferentially transmitted in the presence of BV in this population. CONCLUSIONS: Collectively, these data suggest a role for α4ß7 in HIV infection that is influenced by both viral and host factors including the sequence of the α4ß7 binding motif, the cytokine milieu and BV in the genital tract. The higher frequency of P/SDI/V sequences among South African HIV-1 subtype C viruses may have particular significance for the role of α4ß7 in this geographical region.


Assuntos
Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Integrinas/metabolismo , Replicação Viral , Feminino , Genótipo , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , HIV-1/isolamento & purificação , Humanos , Estudos Prospectivos , África do Sul
18.
AIDS Behav ; 18(5): 826-32, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24647763

RESUMO

Adherence undeniably impacts product effectiveness in microbicide trials, but the connection has proven challenging to quantify using routinely collected behavioral data. We explored this relationship using a nested case-control study in the CAPRISA 004 Tenofovir (TFV) gel HIV prevention trial. Detailed 3-month recall data on sex events, condom and gel use were collected from 72 incident cases and 205 uninfected controls. We then assessed how the relationship between self-reported adherence and HIV acquisition differed between the TFV and placebo gel groups, an interaction effect that should exist if effectiveness increases with adherence. The CAPRISA 004 trial determined that randomization to TFV gel was associated with a significant reduction in risk of HIV acquisition. In our nested case-control study, however, we did not observe a meaningful decrease in the relative odds of infection-TFV versus placebo-as self-reported adherence increased. To the contrary, exploratory sub-group analysis of the case-control data identified greater evidence for a protective effect of TFV gel among participants reporting less than 80 % adherence to the protocol-defined regimen (odds ratio (OR) 0.30; 95 % CI 0.11-0.78) than among those reporting ≥ 80 % adherence (Odds Ratio 0.81; 95 % CI 0.34-1.92). The small number of cases may have inhibited our ability to detect the hypothesized interaction between adherence and effectiveness. Nonetheless, our results re-emphasize the challenges faced by investigators when adherence may be miss-measured, miss-reported, or confounded with the risk of HIV.


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/administração & dosagem , Anti-Infecciosos/administração & dosagem , Infecções por HIV/prevenção & controle , Organofosfonatos/administração & dosagem , Cooperação do Paciente/estatística & dados numéricos , Adenina/administração & dosagem , Adulto , Estudos de Casos e Controles , Preservativos/estatística & dados numéricos , Método Duplo-Cego , Feminino , Humanos , Modelos Logísticos , População Rural/estatística & dados numéricos , África do Sul , Tenofovir , Resultado do Tratamento , População Urbana/estatística & dados numéricos , Cremes, Espumas e Géis Vaginais
19.
AIDS Behav ; 18(5): 820-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24623069

RESUMO

In the CAPRISA 004 trial, adherence was estimated as the proportion of reported sex acts covered by two gel doses, which was assessed by counting returned empty gel applicators. The returned empty applicators were inspected visually in a standardized manner for residue on the outside of the applicator, as an indicator of vaginal insertion. Over 15 months, spanning 11,839 study visits by 838 women, a total of 59,800 returned empty applicators were inspected. By visual assessment, 77.5 % of these applicators appeared to have been inserted. To test the accuracy of the assessment we fitted a Cox model and found that the risk for HIV infection was doubled when less than half of the returned empty applicators had been assessed as not inserted in the vagina. Visual inspection enhanced both the accuracy of the adherence measurement and aided identification of mechanical problems with applicator use experienced by women in the trial.


Assuntos
Adenina/análogos & derivados , Anti-Infecciosos/administração & dosagem , Coito , Sistemas de Liberação de Medicamentos/instrumentação , Infecções por HIV/prevenção & controle , Organofosfonatos/administração & dosagem , Cooperação do Paciente/estatística & dados numéricos , Adenina/administração & dosagem , Administração Intravaginal , Adulto , Método Duplo-Cego , Feminino , Seguimentos , Géis , Humanos , Análise Multivariada , Modelos de Riscos Proporcionais , População Rural/estatística & dados numéricos , África do Sul , Tenofovir , População Urbana/estatística & dados numéricos
20.
AIDS Behav ; 18(5): 841-8, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24633717

RESUMO

High adherence is important in microbicide trials, but no adherence interventions to date have demonstrated empiric improvements in microbicide adherence or effectiveness. Approximately midway during the CAPRISA 004 trial, we implemented a novel adherence intervention (Adherence Support Program-ASP), based on an Information-Motivation-Behavioral Skills model and incorporating a Motivational Interviewing approach. We assessed the impact of the ASP on adherence and tenofovir gel effectiveness using a before-and-after comparison. Of the 889 women in the trial, 774 contributed 486.1 women-years of follow-up pre-ASP and 828 contributed 845.7 women-years of follow-up post-ASP. Median adherence rose from 53.6 % pre-ASP to 66.5 % post-ASP. Detectable tenofovir levels increased from 40.6 % pre-ASP to 62.5 % post-ASP in 64 women who had paired tenofovir drug samples. Gel effectiveness improved post-ASP; HIV incidence in the tenofovir gel arm was 24 % lower pre-ASP compared to 47 % lower post-ASP. Following implementation of the ASP, microbicide adherence improved with a concomitant increase in the effectiveness of tenofovir gel.


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/administração & dosagem , Anti-Infecciosos Locais/administração & dosagem , Infecções por HIV/prevenção & controle , Comportamentos Relacionados com a Saúde , Adesão à Medicação/psicologia , Organofosfonatos/administração & dosagem , Adenina/administração & dosagem , Adulto , Fármacos Anti-HIV/uso terapêutico , Anti-Infecciosos Locais/uso terapêutico , Método Duplo-Cego , Feminino , Géis , Infecções por HIV/epidemiologia , Humanos , Incidência , Adesão à Medicação/estatística & dados numéricos , Modelos Psicológicos , Entrevista Motivacional , Fatores Socioeconômicos , África do Sul/epidemiologia , Tenofovir , Resultado do Tratamento
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