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1.
J Virus Erad ; 9(1): 100317, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36911657

RESUMO

High profile international goals have been set for the elimination of hepatitis B virus (HBV) infection as a public health threat by the year 2030. Developing and expanding equitable, accessible translational HBV research programmes that represent real-world populations are therefore an urgent priority for clinical and academic communities. We present experiences and insights by an expert interdisciplinary group focusing on barriers that impede adults living with HBV infection from participating in clinical studies. Our viewpoint describes barriers we have identified through working in a variety of settings across South Africa, including lack of education and awareness, experiences of stigma and discrimination, challenges for governance and data management, and a burden of complex morbidity. Through identifying these challenges, we propose solutions and interventions, highlight new approaches, and provide a framework for future research.

2.
J Thorac Dis ; 14(10): 4150-4172, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36389298

RESUMO

Pneumococcal infections remain a common global cause of significant morbidity and mortality. The first recommendations for adult pneumococcal vaccination, published in South Africa in 1999, contained information only on the 23-valent polysaccharide vaccine (PPV23). With the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) for use in adults and the perceived uncertainty that most clinicians had regarding use of these vaccines in adults, these vaccine recommendations were updated in 2022. A Working Group, which consisted of individuals in various fields of medical practice in South Africa, who were from different areas of the country, and included clinicians from both the public and private sectors, was assembled to revise the recommendations. The expertise of the participants varied widely, dependent on their training and specialty, and encompassed different organ systems, disease conditions, and/or practice types. Each participant was allocated a different section, based on their expertise, for which they were required to do an extensive review of the current literature and write their section. The entire working group then reviewed the complete document several times, following additional comments and recommendations. This update contains recommendations for the use of both PPV23 and PCV13, either alone, or in sequence, both in vaccine naïve and in previously vaccinated individuals. It includes both age and risk categories, and encompasses the elderly (≥65 years), as well as younger adults (<65 years) with comorbid conditions or with high-risk conditions and/or immunocompromise. It is hoped that this review and its associated vaccine recommendations will clarify for clinicians, from all spheres of practice in South Africa, how, where, and when pneumococcal vaccines should be used in adults, with the ultimate goal of significantly increasing the appropriate use of these vaccines, in order to decrease the substantial morbidity and mortality associated with pneumococcal infections in adults in South Africa. Furthermore, it is hoped that this review of local epidemiological data and the manner in which this information was interpreted in the development of these local vaccine recommendations, could be used as an example for other regions of the world, to tailor their recommendations to locally available epidemiological data.

3.
Sci Rep ; 12(1): 2552, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35169169

RESUMO

There is a need for effective therapy for COVID-19 pneumonia. Convalescent plasma has antiviral activity and early observational studies suggested benefit in reducing COVID-19 severity. We investigated the safety and efficacy of convalescent plasma in hospitalized patients with COVID-19 in a population with a high HIV prevalence and where few therapeutic options were available. We performed a double-blinded, multicenter, randomized controlled trial in one private and three public sector hospitals in South Africa. Adult participants with COVID-19 pneumonia requiring non-invasive oxygen were randomized 1:1 to receive a single transfusion of 200 mL of either convalescent plasma or 0.9% saline solution. The primary outcome measure was hospital discharge and/or improvement of ≥ 2 points on the World Health Organisation Blueprint Ordinal Scale for Clinical Improvement by day 28 of enrolment. The trial was stopped early for futility by the Data and Safety Monitoring Board. 103 participants, including 21 HIV positive individuals, were randomized at the time of premature trial termination: 52 in the convalescent plasma and 51 in the placebo group. The primary outcome occurred in 31 participants in the convalescent plasma group and and 32 participants in the placebo group (relative risk 1.03 (95% CI 0.77 to 1.38). Two grade 1 transfusion-related adverse events occurred. Participants who improved clinically received convalescent plasma with a higher median anti-SARS-CoV-2 neutralizing antibody titre compared with those who did not (298 versus 205 AU/mL). Our study contributes additional evidence for recommendations against the use of convalescent plasma for COVID-19 pneumonia. Safety and feasibility in this population supports future investigation for other indications.


Assuntos
COVID-19/terapia , Adulto , COVID-19/mortalidade , COVID-19/patologia , COVID-19/virologia , Método Duplo-Cego , Feminino , Infecções por HIV/complicações , Hospitais Públicos , Humanos , Imunização Passiva , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Efeito Placebo , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença , África do Sul , Resultado do Tratamento , Soroterapia para COVID-19
5.
J Infect ; 81(1): 121-130, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32360882

RESUMO

OBJECTIVES: Prompted by international targets for elimination of hepatitis B virus (HBV), we set out to characterise individuals with HBV monoinfection vs. those coinfected with HBV/HIV, to evaluate the impact of therapy and to guide improvements in clinical care. METHODS: We report observational data from a real world cross-sectional cohort of 115 adults with chronic hepatitis B infection (CHB), at a university hospital in Cape Town, South Africa. HIV coinfection was present in 39 (34%) subjects. We recorded cross-sectional demographic, clinical and laboratory data. RESULTS: Compared to those with HIV coinfection, HBV monoinfected adults were less likely to be HBeAg-positive (p=0.01), less likely to have had assessment with elastography (p<0.0001), and less likely to be on antiviral treatment (p<0.0001); they were more likely to have detectable HBV viraemia (p=0.04), and more likely to have features of liver disease including moderate/severe thrombocytopaenia (p=0.007), elevated bilirubin (p=0.004), and elevated APRI score (p=0.02). Three cases of hepatocellular carcinoma all arose in HBV monoinfection. CONCLUSIONS: Our data demonstrate that individuals with HBV monoinfection may be disadvantaged compared to those with HIV coinfection, highlighting potential systematic inequities in referral, monitoring and treatment.


Assuntos
Coinfecção , Infecções por HIV , Hepatite B , Adulto , Coinfecção/tratamento farmacológico , Coinfecção/epidemiologia , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Vírus da Hepatite B , Humanos , África do Sul/epidemiologia
6.
Front Immunol ; 10: 1844, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440240

RESUMO

Cytolytic CD4+ T cells play a prominent role in chronic viral infection. CD4+ CTLs clones specific for HIV-1 Nef and Gag are capable of killing HIV-1 infected CD4+ T cells and macrophages. Additionally, HIV-specific cytolytic CD4+ T cell responses in acute HIV infection are predictive of disease progression. CD57 expression on CD4s identifies cytolytic cells. These cells were dramatically increased in chronic HIV infection. CD57 expression correlated with cytolytic granules, granzyme B and perforin expression. They express lower CCR5 compared to CD57- cells, have less HIV total DNA, and were a minor component of the HIV reservoir. A small percentage of CD57+ CD4+ CTLs from EC were HIV-specific, could upregulate IFNγ with Gag peptide stimulation, express cytolytic granule markers and maintain TbethighEomes+ transcription factor phenotype. This was not observed in viraemic controllers. The maintenance of HIV-specific CD4 cytolytic function in Elite controllers together with CD8 CTLs may be important for the control of HIV viraemia and of potential relevance to cure strategies.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Antígenos CD57/análise , Infecções por HIV/imunologia , Sobreviventes de Longo Prazo ao HIV , Subpopulações de Linfócitos T/imunologia , Viremia/imunologia , Biomarcadores , Linfócitos T CD4-Positivos/química , Citocinas/sangue , Citotoxicidade Imunológica , Progressão da Doença , Infecções por HIV/sangue , Humanos , Memória Imunológica , Imunofenotipagem , Ativação Linfocitária , Superantígenos/imunologia , Subpopulações de Linfócitos T/química , Transcriptoma , Carga Viral , Viremia/sangue
9.
Lancet Infect Dis ; 17(3): 296-304, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27914856

RESUMO

BACKGROUND: HIV-1 drug resistance to older thymidine analogue nucleoside reverse transcriptase inhibitor drugs has been identified in sub-Saharan Africa in patients with virological failure of first-line combination antiretroviral therapy (ART) containing the modern nucleoside reverse transcriptase inhibitor tenofovir. We aimed to investigate the prevalence and correlates of thymidine analogue mutations (TAM) in patients with virological failure of first-line tenofovir-containing ART. METHODS: We retrospectively analysed patients from 20 studies within the TenoRes collaboration who had locally defined viral failure on first-line therapy with tenofovir plus a cytosine analogue (lamivudine or emtricitabine) plus a non-nucleoside reverse transcriptase inhibitor (NNRTI; nevirapine or efavirenz) in sub-Saharan Africa. Baseline visits in these studies occurred between 2005 and 2013. To assess between-study and within-study associations, we used meta-regression and meta-analyses to compare patients with and without TAMs for the presence of resistance to tenofovir, cytosine analogue, or NNRTIs. FINDINGS: Of 712 individuals with failure of first-line tenofovir-containing regimens, 115 (16%) had at least one TAM. In crude comparisons, patients with TAMs had lower CD4 counts at treatment initiation than did patients without TAMs (60·5 cells per µL [IQR 21·0-128·0] in patients with TAMS vs 95·0 cells per µL [37·0-177·0] in patients without TAMs; p=0·007) and were more likely to have tenofovir resistance (93 [81%] of 115 patients with TAMs vs 352 [59%] of 597 patients without TAMs; p<0·0001), NNRTI resistance (107 [93%] vs 462 [77%]; p<0·0001), and cytosine analogue resistance (100 [87%] vs 378 [63%]; p=0·0002). We detected associations between TAMs and drug resistance mutations both between and within studies; the correlation between the study-level proportion of patients with tenofovir resistance and TAMs was 0·64 (p<0·0001), and the odds ratio for tenofovir resistance comparing patients with and without TAMs was 1·29 (1·13-1·47; p<0·0001) INTERPRETATION: TAMs are common in patients who have failure of first-line tenofovir-containing regimens in sub-Saharan Africa, and are associated with multidrug resistant HIV-1. Effective viral load monitoring and point-of-care resistance tests could help to mitigate the emergence and spread of such strains. FUNDING: The Wellcome Trust.


Assuntos
Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Inibidores da Transcriptase Reversa/uso terapêutico , Tenofovir/uso terapêutico , Adulto , África Subsaariana , Alcinos , Terapia Antirretroviral de Alta Atividade , Benzoxazinas/farmacologia , Benzoxazinas/uso terapêutico , Ciclopropanos , Farmacorresistência Viral/efeitos dos fármacos , Feminino , Humanos , Lamivudina/farmacologia , Lamivudina/uso terapêutico , Masculino , Mutação/genética , Nevirapina/uso terapêutico , Estudos Retrospectivos , Falha de Tratamento , Carga Viral/efeitos dos fármacos
10.
South Afr J HIV Med ; 18(1): 776, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29568644

RESUMO

These guidelines are intended as an update to those published in the Southern African Journal of HIV Medicine in 2014 and the update on when to initiate antiretroviral therapy in 2015. Since the release of the previous guidelines, the scale-up of antiretroviral therapy (ART) in southern Africa has continued. New antiretroviral drugs have become available with improved efficacy, safety and robustness. The guidelines are intended for countries in the southern African region, which vary between lower and middle income.

11.
Database (Oxford) ; 2014: bat082, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24504151

RESUMO

Substantial amounts of data have been generated from patient management and academic exercises designed to better understand the human immunodeficiency virus (HIV) epidemic and design interventions to control it. A number of specialized databases have been designed to manage huge data sets from HIV cohort, vaccine, host genomic and drug resistance studies. Besides databases from cohort studies, most of the online databases contain limited curated data and are thus sequence repositories. HIV drug resistance has been shown to have a great potential to derail the progress made thus far through antiretroviral therapy. Thus, a lot of resources have been invested in generating drug resistance data for patient management and surveillance purposes. Unfortunately, most of the data currently available relate to subtype B even though >60% of the epidemic is caused by HIV-1 subtype C. A consortium of clinicians, scientists, public health experts and policy markers working in southern Africa came together and formed a network, the Southern African Treatment and Resistance Network (SATuRN), with the aim of increasing curated HIV-1 subtype C and tuberculosis drug resistance data. This article describes the HIV-1 data curation process using the SATuRN Rega database. The data curation is a manual and time-consuming process done by clinical, laboratory and data curation specialists. Access to the highly curated data sets is through applications that are reviewed by the SATuRN executive committee. Examples of research outputs from the analysis of the curated data include trends in the level of transmitted drug resistance in South Africa, analysis of the levels of acquired resistance among patients failing therapy and factors associated with the absence of genotypic evidence of drug resistance among patients failing therapy. All these studies have been important for informing first- and second-line therapy. This database is a free password-protected open source database available on www.bioafrica.net. Database URL: http://www.bioafrica.net/regadb/


Assuntos
Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Bases de Dados Genéticas , Farmacorresistência Viral/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Administração dos Cuidados ao Paciente , Vigilância da População , África Austral , Mineração de Dados , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Pesquisa
12.
PLoS One ; 7(10): e47799, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23094091

RESUMO

BACKGROUND: HLA class I genotype is a major determinant of the outcome of HIV infection, and the impact of certain alleles on HIV disease outcome is well studied. Recent studies have demonstrated that certain HLA class I alleles that are in linkage disequilibrium, such as HLA-A*74 and HLA-B*57, appear to function co-operatively to result in greater immune control of HIV than mediated by either single allele alone. We here investigate the extent to which HLA alleles--irrespective of linkage disequilibrium--function co-operatively. METHODOLOGY/PRINCIPAL FINDINGS: We here refined a computational approach to the analysis of >2000 subjects infected with C-clade HIV first to discern the individual effect of each allele on disease control, and second to identify pairs of alleles that mediate 'co-operative additive' effects, either to improve disease suppression or to contribute to immunological failure. We identified six pairs of HLA class I alleles that have a co-operative additive effect in mediating HIV disease control and four hazardous pairs of alleles that, occurring together, are predictive of worse disease outcomes (q<0.05 in each case). We developed a novel 'sharing score' to quantify the breadth of CD8+ T cell responses made by pairs of HLA alleles across the HIV proteome, and used this to demonstrate that successful viraemic suppression correlates with breadth of unique CD8+ T cell responses (p = 0.03). CONCLUSIONS/SIGNIFICANCE: These results identify co-operative effects between HLA Class I alleles in the control of HIV-1 in an extended Southern African cohort, and underline complementarity and breadth of the CD8+ T cell targeting as one potential mechanism for this effect.


Assuntos
Alelos , Infecções por HIV/genética , HIV-1/imunologia , Antígenos HLA/genética , Imunidade Celular/genética , Viremia/genética , Adulto , África Austral , Análise de Variância , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Frequência do Gene , Genótipo , Infecções por HIV/imunologia , Infecções por HIV/virologia , Antígenos HLA/imunologia , Humanos , Desequilíbrio de Ligação , Projetos de Pesquisa , Viremia/imunologia , Viremia/virologia
13.
J Virol ; 86(21): 11493-500, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22896606

RESUMO

Genetic variation within the HLA-B locus has the strongest impact on HIV disease progression of any polymorphisms within the human genome. However, identifying the exact mechanism involved is complicated by several factors. HLA-Bw4 alleles provide ligands for NK cells and for CD8 T cells, and strong linkage disequilibrium between HLA class I alleles complicates the discrimination of individual HLA allelic effects from those of other HLA and non-HLA alleles on the same haplotype. Here, we exploit an experiment of nature involving two recently diverged HLA alleles, HLA-B*42:01 and HLA-B*42:02, which differ by only a single amino acid. Crucially, they occur primarily on identical HLA class I haplotypes and, as Bw6 alleles, do not act as NK cell ligands and are therefore largely unconfounded by other genetic factors. We show that in an outbred cohort (n = 2,093) of HIV C-clade-infected individuals, a single amino acid change at position 9 of the HLA-B molecule critically affects peptide binding and significantly alters the cytotoxic T lymphocyte (CTL) epitopes targeted, measured directly ex vivo by gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay (P = 2 × 10(-10)) and functionally through CTL escape mutation (P = 2 × 10(-8)). HLA-B*42:01, which presents multiple Gag epitopes, is associated with a 0.52 log(10) lower viral-load set point than HLA-B*42:02 (P = 0.02), which presents no p24 Gag epitopes. The magnitude of this effect from a single amino acid difference in the HLA-A*30:01/B*42/Cw*17:01 haplotype is equivalent to 75% of that of HLA-B*57:03, the most protective HLA class I allele in this population. This naturally controlled experiment represents perhaps the clearest demonstration of the direct impact of a particular HIV-specific CTL on disease control.


Assuntos
Resistência à Doença , Infecções por HIV/imunologia , Antígeno HLA-B27/genética , Antígeno HLA-B27/imunologia , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Humanos , Carga Viral
14.
Lancet ; 380(9845): 889-98, 2012 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-22901955

RESUMO

BACKGROUND: Robust evidence of the effectiveness of task shifting of antiretroviral therapy (ART) from doctors to other health workers is scarce. We aimed to assess the effects on mortality, viral suppression, and other health outcomes and quality indicators of the Streamlining Tasks and Roles to Expand Treatment and Care for HIV (STRETCH) programme, which provides educational outreach training of nurses to initiate and represcribe ART, and to decentralise care. METHODS: We undertook a pragmatic, parallel, cluster-randomised trial in South Africa between Jan 28, 2008, and June 30, 2010. We randomly assigned 31 primary-care ART clinics to implement the STRETCH programme (intervention group) or to continue with standard care (control group). The ratio of randomisation depended on how many clinics were in each of nine strata. Two cohorts were enrolled: eligible patients in cohort 1 were adults (aged ≥16 years) with CD4 counts of 350 cells per µL or less who were not receiving ART; those in cohort 2 were adults who had already received ART for at least 6 months and were being treated at enrolment. The primary outcome in cohort 1 was time to death (superiority analysis). The primary outcome in cohort 2 was the proportion with undetectable viral loads (<400 copies per mL) 12 months after enrolment (equivalence analysis, prespecified difference <6%). Patients and clinicians could not be masked to group assignment. The interim analysis was blind, but data analysts were not masked after the database was locked for final analysis. Analyses were done by intention to treat. This trial is registered, number ISRCTN46836853. FINDINGS: 5390 patients in cohort 1 and 3029 in cohort 2 were in the intervention group, and 3862 in cohort 1 and 3202 in cohort 2 were in the control group. Median follow-up was 16·3 months (IQR 12·2-18·0) in cohort 1 and 18·0 months (18·0-18·0) in cohort 2. In cohort 1, 997 (20%) of 4943 patients analysed in the intervention group and 747 (19%) of 3862 in the control group with known vital status at the end of the trial had died. Time to death did not differ (hazard ratio [HR] 0·94, 95% CI 0·76-1·15). In a preplanned subgroup analysis of patients with baseline CD4 counts of 201-350 cells per µL, mortality was slightly lower in the intervention group than in the control group (0·73, 0·54-1.00; p=0·052), but it did not differ between groups in patients with baseline CD4 of 200 cells per µL or less (0·94, 0·76-1·15; p=0·577). In cohort 2, viral load suppression 12 months after enrolment was equivalent in intervention (2156 [71%] of 3029 patients) and control groups (2230 [70%] of 3202; risk difference 1·1%, 95% CI -2·4 to 4·6). INTERPRETATION: Expansion of primary-care nurses' roles to include ART initiation and represcription can be done safely, and improve health outcomes and quality of care, but might not reduce time to ART or mortality. FUNDING: UK Medical Research Council, Development Cooperation Ireland, and Canadian International Development Agency.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/enfermagem , Enfermagem de Atenção Primária/métodos , Adulto , Contagem de Linfócito CD4 , Atenção à Saúde/organização & administração , Prescrições de Medicamentos/enfermagem , Feminino , Infecções por HIV/imunologia , Infecções por HIV/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Atenção Primária à Saúde/organização & administração , África do Sul/epidemiologia , Resultado do Tratamento , Carga Viral
15.
S Afr Med J ; 101(5): 328-31, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21837876

RESUMO

BACKGROUND: There is a global emergence of resistance against commonly prescribed antibiotics. Empirical antibiotic prescribing should be guided by local antimicrobial susceptibility patterns. AIM: To dentify organisms and determine antibiotic susceptibility in urinary tract infections (UTIs) at 3 Military Hospital, Bloemfontein. METHODS: All urine samples collected during 2008 were analysed. The first positive urine culture per patient collected from the casualty, gynaecology, internal medicine and surgical outpatient departments were included. Only adult patients (> 12 years old) were included. Prior use of antibiotics and underlying conditions were determined from electronic and paper-based patient and pharmacy records. RESULTS: Positive cultures (N = 65) were divided into uncomplicated (N = 28) and complicated (N = 37) UTIs. Escherichia coli (E. coli) was the most common uropathogen in uncomplicated (75%) and complicated (59%) UTIs. In uncomplicated UTIs, trimethoprim-sulfamethoxazole (TMP-SMX) (54%) and amnoxicillin (46%) had the highest rates of resistance. Nitrofurantoin and ciprofloxacin had sensitivity rates of 89%. Co-amoxdclav was most commonly prescribed (36%). In complicated UTIS, TMP-SMX (68%) and amoxicillin (65%) had the highest resistance rates, followed by ciprofloxacin (41%). Nitrofurantoin had a sensitivity rate of 73%. Ciprofloxacin was prescribed most often (35%). All E. coli UTI isolates were sensitive to nitrofurantoin. CONCLUSION: E. coli remains the most common uropathogen. TMP-SMX and amoxicillin are of no value in this population with UTIs. Uncomplicated UTIs can be treated effectively with nitrofurantoin; this will lead to cost savings and sparing quinolones as a class of antibiotics known to induce resistance. In this setting, ciprofloxacin should not be used empirically for complicated UTIs.


Assuntos
Assistência Ambulatorial/normas , Antibacterianos/administração & dosagem , Competência Clínica , Prescrições de Medicamentos/normas , Resistência Microbiana a Medicamentos , Infecções Urinárias/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Urinárias/microbiologia , Infecções Urinárias/urina , Urina/microbiologia , Adulto Jovem
16.
PLoS One ; 6(4): e19018, 2011 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-21544209

RESUMO

We lack the understanding of why HIV-infected individuals in South Africa progress to AIDS. We hypothesised that in end-stage disease there is a shifting dynamic between T cell imposed immunity and viral immune escape, which, through both compensatory and reverting viral mutations, results in increased viral fitness, elevated plasma viral loads and disease progression. We explored how T cell responses, viral adaptation and viral fitness inter-relate in South African cohorts recruited from Bloemfontein, the Free State (n = 278) and Durban, KwaZulu-Natal (n = 775). Immune responses were measured by γ-interferon ELISPOT assays. HLA-associated viral polymorphisms were determined using phylogenetically corrected techniques, and viral replication capacity (VRC) was measured by comparing the growth rate of gag-protease recombinant viruses against recombinant NL4-3 viruses. We report that in advanced disease (CD4 counts <100 cells/µl), T cell responses narrow, with a relative decline in Gag-directed responses (p<0.0001). This is associated with preserved selection pressure at specific viral amino acids (e.g., the T242N polymorphism within the HLA-B*57/5801 restricted TW10 epitope), but with reversion at other sites (e.g., the T186S polymorphism within the HLA-B*8101 restricted TL9 epitope), most notably in Gag and suggestive of "immune relaxation". The median VRC from patients with CD4 counts <100 cells/µl was higher than from patients with CD4 counts ≥ 500 cells/µl (91.15% versus 85.19%, p = 0.0004), potentially explaining the rise in viral load associated with disease progression. Mutations at HIV Gag T186S and T242N reduced VRC, however, in advanced disease only the T242N mutants demonstrated increasing VRC, and were associated with compensatory mutations (p = 0.013). These data provide novel insights into the mechanisms of HIV disease progression in South Africa. Restoration of fitness correlates with loss of viral control in late disease, with evidence for both preserved and relaxed selection pressure across the HIV genome. Interventions that maintain viral fitness costs could potentially slow progression.


Assuntos
Síndrome da Imunodeficiência Adquirida/genética , Síndrome da Imunodeficiência Adquirida/virologia , Contagem de Linfócito CD4 , Progressão da Doença , ELISPOT , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Mutação/genética , Polimorfismo Genético/genética , África do Sul , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene nef do Vírus da Imunodeficiência Humana/genética , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética
17.
J Immunol ; 186(10): 5675-86, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21498667

RESUMO

The potential contribution of HLA-A alleles to viremic control in chronic HIV type 1 (HIV-1) infection has been relatively understudied compared with HLA-B. In these studies, we show that HLA-A*7401 is associated with favorable viremic control in extended southern African cohorts of >2100 C-clade-infected subjects. We present evidence that HLA-A*7401 operates an effect that is independent of HLA-B*5703, with which it is in linkage disequilibrium in some populations, to mediate lowered viremia. We describe a novel statistical approach to detecting additive effects between class I alleles in control of HIV-1 disease, highlighting improved viremic control in subjects with HLA-A*7401 combined with HLA-B*57. In common with HLA-B alleles that are associated with effective control of viremia, HLA-A*7401 presents highly targeted epitopes in several proteins, including Gag, Pol, Rev, and Nef, of which the Gag epitopes appear immunodominant. We identify eight novel putative HLA-A*7401-restricted epitopes, of which three have been defined to the optimal epitope. In common with HLA-B alleles linked with slow progression, viremic control through an HLA-A*7401-restricted response appears to be associated with the selection of escape mutants within Gag epitopes that reduce viral replicative capacity. These studies highlight the potentially important contribution of an HLA-A allele to immune control of HIV infection, which may have been concealed by a stronger effect mediated by an HLA-B allele with which it is in linkage disequilibrium. In addition, these studies identify a factor contributing to different HIV disease outcomes in individuals expressing HLA-B*5703.


Assuntos
Infecções por HIV/imunologia , HIV-1/imunologia , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Viremia/imunologia , África , Alelos , Contagem de Linfócito CD4 , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Citometria de Fluxo , Infecções por HIV/genética , Infecções por HIV/virologia , HIV-1/genética , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Humanos , Desequilíbrio de Ligação , Dados de Sequência Molecular , Análise de Sequência de Proteína , Carga Viral , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene pol do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene rev do Vírus da Imunodeficiência Humana/imunologia
18.
Antivir Ther ; 14(7): 975-84, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19918101

RESUMO

BACKGROUND: We aimed to characterize the molecular epidemiology of HIV type-1 (HIV-1) and the prevalence of drug-associated mutations prior to initiating highly active antiretroviral therapy (HAART) in the Free State province, South Africa. The Free State has a population of 3 million, an antenatal HIV prevalence of approximately 34% and a well established infrastucture for antiretroviral (ARV) provision. METHODS: HIV-1 polymerase genes were sequenced from 425 HAART-naive HIV-1-positive patients at voluntary primary healthcare HIV testing centres, who were subsequently attending district centres for assessment for commencing ARVs. Patients (>18 years) were sampled randomly with no exclusion for gender or clinical criteria. Sequences were analysed according to phylogeny and drug resistance. RESULTS: Phylogenetic clustering within the cohort was suggestive of multiple introductions of subtype C virus into the region. Drug resistance mutations (according to the International AIDS Society-USA classification) were distributed randomly across the cohort phylogeny with an overall prevalence of 2.3% in the sampled patients. When stratified according to CD4(+) T-cell count, the prevalence of resistance was 3.6%, 0.9% and 1.2% for CD4(+) T-cell counts <100, 200-350 and >500 cells/microl, respectively, and was most common for non-nucleoside reverse transcriptase inhibitor resistance (3.1% in patients with CD4(+) T-cell count <100 cells/microl). We surveyed all drug-selected mutations and found further significant clustering among patients with low CD4(+) T-cell counts (P=0.003), suggesting unrecognized exposure to ARVs. CONCLUSIONS: In the Free State population, there was a statistical association between low CD4(+) T-cell counts and drug-associated viral polymorphisms. Our data advocate the benefit of detailed history taking from patients starting HAART at low CD4(+) T-cell counts with close follow-up of the virological response.


Assuntos
Farmacorresistência Viral Múltipla/genética , Infecções por HIV/epidemiologia , HIV-1/genética , Mutação , Adulto , Terapia Antirretroviral de Alta Atividade , Contagem de Linfócito CD4 , Estudos de Coortes , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , HIV-1/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , RNA Viral/análise , RNA Viral/genética , África do Sul/epidemiologia
19.
Clin Infect Dis ; 48(10): 1429-32, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-19364287

RESUMO

Most guidelines call for the discontinuation of treatment with tumor necrosis factor blockers in patients who develop tuberculosis. We report a case of life-threatening tuberculosis paradoxical reaction involving the lungs caused by withdrawal of the anti-tumor necrosis factor antibody adalimumab. Clinical improvement occurred only after resumption of adalimumab treatment.


Assuntos
Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/patologia , Adalimumab , Adulto , Anticorpos Monoclonais Humanizados , Feminino , Humanos , Pulmão/patologia , Radiografia Torácica
20.
Trials ; 9: 21, 2008 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-18433494

RESUMO

BACKGROUND: A major barrier to accessing free government-provided antiretroviral treatment (ART) in South Africa is the shortage of suitably skilled health professionals. Current South African guidelines recommend that only doctors should prescribe ART, even though most primary care is provided by nurses. We have developed an effective method of educational outreach to primary care nurses in South Africa. Evidence is needed as to whether primary care nurses, with suitable training and managerial support, can initiate and continue to prescribe and monitor ART in the majority of ART-eligible adults. METHODS/DESIGN: This is a protocol for a pragmatic cluster randomised trial to evaluate the effectiveness of a complex intervention based on and supporting nurse-led antiretroviral treatment (ART) for South African patients with HIV/AIDS, compared to current practice in which doctors are responsible for initiating ART and continuing prescribing. We will randomly allocate 31 primary care clinics in the Free State province to nurse-led or doctor-led ART. Two groups of patients aged 16 years and over will be included: a) 7400 registering with the programme with CD4 counts of

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