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1.
J Glob Health ; 12: 04004, 2022.
Article in English | MEDLINE | ID: mdl-35136596

ABSTRACT

BACKGROUND: South Africa, with the highest burden of HIV infection globally, has made huge strides in its HIV/ART programme, but AIDS deaths have not decreased proportionally to ART uptake. Advanced HIV disease (CD4 < 200 cells/mm3) persists, and CD4 count testing is being overlooked since universal test-and-treat was implemented. Point-of-care CD4 testing could address this gap and assure differentiated care to these vulnerable patients with low CD4 counts. METHODS: A time randomised implementation trial was conducted, enrolling 603 HIV positive non-ART, not pregnant patients at a primary health care clinic in Durban, South Africa. Weeks were randomised to either point-of-care CD4 testing (n = 305 patients) or standard-of-care central laboratory CD4 testing (n = 298 patients) to assess the proportion initiating ART at 3 months. Cox regression, with robust standard errors adjusting for clustering by week, were used to assess the relationship between treatment initiation and arm. RESULTS: Among the 578 (299 point-of-care and 279 standard-of-care) patients eligible for analysis, there was no significant difference in the number of eligible patients initiating ART within 3 months in the point-of-care (73%) and the standard-of-care (68%) groups (P = 0.112). The time-to-treat analysis was not significantly different in patients with CD4 counts of 201-500 cells/mm3 which could have been due to appointment scheduling to cope with the large burden of cases. However, in patients with advanced HIV disease (CD4 < 200cells/mm3) 65% more patients started ART earlier in the point-of-care group (HR 1.65 (95% confidence interval (CI) = 0.99-2.75; P = 0.052) compared to the standard-of-care group. CONCLUSIONS: Point-of-care testing decreased time-to-treatment in those with advanced HIV disease. With universal test and treat for HIV, rollout of simple point-of-care CD4 testing would ensure early diagnosis of advanced HIV disease and facilitate differentiated care for these vulnerable patients as per the World Health Organisation 2020 target product profile for point-of-care CD4 testing. TRIAL REGISTRATION: ISRCTN14220457.


Subject(s)
Anti-HIV Agents , HIV Infections , Anti-HIV Agents/therapeutic use , CD4 Lymphocyte Count , Female , HIV Infections/drug therapy , HIV Infections/therapy , Humans , Point-of-Care Systems , Pregnancy , South Africa
2.
Diagnostics (Basel) ; 10(2)2020 Feb 01.
Article in English | MEDLINE | ID: mdl-32024166

ABSTRACT

BACKGROUND: The high burden of disease in South Africa presents challenges to public health services. Point-of-care (POC) technologies have the potential to address these gaps and improve healthcare systems. This study ascertained the acceptability and impact of POC CD4 testing on patients' health and clinical management. METHODS: We conducted a qualitative survey study with patients (n = 642) and healthcare providers (n = 13) at the Lancers Road (experienced POC) and Chesterville (non-experienced POC) primary healthcare (PHC) clinics from September 2015 to June 2016. RESULTS: Patients (99%) at Lancers and Chesterville PHCs were positive about POC CD4 testing, identifying benefits: No loss/delay of test results (6.4%), cost/time saving (19.5%), and no anxiety (5.1%), and 58.2% were ready to initiate treatment. Significantly more patients at Chesterville than Lancers Road PHC felt POC would provide rapid clinical decision making (64.7% vs. 48.1%; p < 0.0001) and better clinic accessibility (40.4% vs. 24.7%; p < 0.0001) respectively. Healthcare providers thought same-day CD4 results would impact: Clinical management (46.2%), patient readiness (46.2%), and adherence (23.0%), and would reduce follow-up visits (7.7%), while 38.5% were concerned that further tests and training (15.4%) were required before antiretroviral therapy (ART) initiation. CONCLUSION: The high acceptability of POC CD4 testing and the immediate health, structural, and clinical management benefits necessitates POC implementation studies.

3.
Lancet Glob Health ; 7(12): e1717-e1727, 2019 12.
Article in English | MEDLINE | ID: mdl-31708152

ABSTRACT

BACKGROUND: WHO guidelines recommend co-trimoxazole prophylaxis for HIV-exposed, HIV-uninfected infants. These guidelines date back to an era in which HIV testing of infants was impossible and mothers had poor access to antiretroviral treatment. To determine whether this guideline requires revision in the current era of effective prevention of mother-to-child transmission and early infant diagnosis programmes, we aimed to investigate whether receiving no co-trimoxazole prophylaxis is inferior to receiving co-trimoxazole prophylaxis in the resulting incidence of grade 3 or 4 common childhood illnesses or mortality in breastfed HIV-exposed, HIV-uninfected infants. METHODS: We investigated our aim in a randomised controlled, non-inferiority trial. We enrolled the HIV-negative infants of mothers living with HIV who were actively involved in transmission prevention programmes in two clinics in Durban, South Africa. Infants were included in the study if they were breastfeeding at the screening and enrolment visits, and their mother was planning to breastfeed for at least 6 months; were a singleton birth and had a birthweight of 2 kg or more; had no clinically observed genetic disorders; and had no serious illnesses and had not received antibiotics or traditional medications (such as herbal remedies). Infants were randomly assigned (1:1) to receive co-trimoxazole or no co-trimoxazole. In the co-trimoxazole group, infants received the drug until all exposure to HIV had ceased (ie, 6 weeks after last exposure to breastmilk) and the infant was confirmed to be uninfected with HIV. The drug was administered by mothers in once-daily regimens of 20 mg trimethoprim and 100 mg sulfamethoxazole orally (age <6 months or bodyweight <5 kg), or 40 mg trimethoprim and 200 mg sulfamethoxazole orally (age >6 months or bodyweight >5 kg). Clinical and laboratory staff always remained masked to group assignment, but mothers and study counsellors were not. Infants and their mothers attended study visits at ages 6 weeks (for enrolment and randomisation), 10 weeks, 14 weeks, and then monthly from 4 to 12 months. Our primary outcome was the incidence of grade 3 or 4 common childhood illnesses (pneumonia or diarrhoea) or mortality in breastfed HIV-exposed, HIV-uninfected infants by age 12 months. A non-inferiority bound of 5% was used. The study is registered with the Pan African Clinical Trials Registry, number PACTR201311000621110, and the South African National Clinical Trials Registry, number DOH-27-0614-4728. FINDINGS: We screened 1570 mother-child pairs for study enrolment, from whom (78%) eligible infants were enrolled into the study between Oct 16, 2013, and May 23, 2018. Of the infants enrolled, 611 (50%) were randomly assigned to the co-trimoxazole group and 609 (50%) were randomly assigned to the no co-trimoxazole group. One (<1%) infant in the no co-trimoxazole group was excluded from the analysis of the final outcomes for having received traditional medicine (which only became apparent after randomisation); therefore, 611 (50%) infants in the co-trimoxazole group and 608 (50%) infants in the no co-trimoxazole group were included in the final intention-to-treat analysis. 136 (22%) infants in the co-trimoxazole group and 139 (23%) infants in the no co-trimoxazole group did not complete the 12-month study visit, predominantly because of loss to follow-up (93 [15%] infants in the co-trimoxazole group; 90 [15%] infants in the no co-trimoxazole group). The cumulative probability of the composite primary outcome was 0·114 (95% CI 0·076 to 0·147; 49 events) in the co-trimoxazole group versus 0·0795 (0·044 to 0·115; 39 events) in the no co-trimoxazole group. The risk difference (no co-trimoxazole group minus co-trimoxazole group) was -0·0319 (-0·075 to 0·011), meaning that the risk was around 3 percentage points lower in the no co-trimoxazole group on the additive scale. INTERPRETATION: We can conclude that no co-trimoxazole is not inferior to daily co-trimoxazole among breastfed HIV-exposed, HIV-uninfected infants whose mothers are accessing a prevention of mother-to-child transmission programme in an area unaffected by malaria. We therefore believe that WHO should revise the co-trimoxazole guidelines for HIV-exposed, HIV-uninfected infants in areas unaffected by malaria. FUNDING: HIV Prevention Research Unit of the South African Medical Research Council and the Family Larsson-Rosenquist Foundation.


Subject(s)
Antibiotic Prophylaxis , HIV Infections/prevention & control , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Female , Humans , Infant , Infant Mortality , Male , Morbidity , South Africa/epidemiology , Treatment Outcome
4.
South Afr J HIV Med ; 20(1): 985, 2019.
Article in English | MEDLINE | ID: mdl-31616575

ABSTRACT

BACKGROUND: With the largest antiretroviral therapy (ART) programme globally, demand for effective HIV management is increasing in South Africa. While viral load (VL) testing is conducted, VL follow-up and management are sub-optimal. OBJECTIVES: The objective of this study was to address gaps in the VL cascade to improve VL testing and management. METHODS: Antiretroviral therapy records were sampled for an in-depth review. The study team then reviewed individual records, focusing on ART management, virological suppression and retention. Multifaceted interventions focused on virological control, including a clinical summary chart for ART care; streamlining laboratory results receipt and management; monitoring VL suppression, flagging virological failure and missed visits for follow-up; down-referral of stable patients eligible for the chronic club system; and training of personnel and patients. RESULTS: Pre-intervention, 78% (94/120) of eligible patients had VL tests, versus 92% (145/158) post-intervention (p = 0.0009). Pre-intervention, 59% (71/120) of patients accessed their VL results, versus 86% (136/158) post-intervention (p < 0.0001). Post-intervention, 73% (19/26) of patients eligible for ART change were appropriately managed, versus 11% (4/36) pre-intervention (p < 0.0001). Only 27% had no regimen changes (7/26) post-intervention, versus 81% (29/36) pre-intervention (p < 0.0001). CONCLUSION: Service delivery was streamlined to facilitate HIV services by focusing on VL test monitoring, protocol training and accessibility of results, thereby improving clinical management.

5.
BMJ Open ; 6(7): e010656, 2016 07 12.
Article in English | MEDLINE | ID: mdl-27406638

ABSTRACT

INTRODUCTION: No randomised controlled trial (RCT) has examined the efficacy of cotrimoxazole (CTX) prophylaxis in HIV-exposed uninfected (HEU) infants during the breastfeeding period, in this new era of effective prevention of mother-to-child transmission (PMTCT) prophylaxis. The efficacy of CTX prophylaxis has presently been demonstrated only in HIV-infected children. The absence of proven benefits in HEU breastfed infants associated with infectious diseases justifies an RCT as proposed. Herewith lies the rationale for conducting the proposed study. METHODS: A partially blinded RCT is proposed to evaluate the efficacy of CTX prophylaxis administered from 6 weeks of age to HEU infants receiving a PMTCT regimen. A non-inferiority design will be used, randomising 1298 infants to receive CTX or not to receive CTX. Participants will be reviewed at the following time points: 6 weeks (enrolment and randomisation), 10 weeks, 14 weeks, 4 months and monthly thereafter until 12 months of age. They will be evaluated for anthropometric growth, interval illness, CTX adherence, signs and symptoms of study drug toxicity, concomitant medication use, breastfeeding status and HIV infection status. The study will compare the incidence of grade 3 and grade 4 common childhood illnesses (focusing on pneumonia and diarrhoea) and all-cause mortality until 12 months of age. In a subset of participants, we will compare grade 3 and grade 4 haemoglobin and alanine aminotransferase results as well as investigate gut integrity. ETHICS AND DISSEMINATION: The study has ethical approval from the University of KwaZulu-Natal Biomedical Research Ethics Committee (BFC212/13). TRIAL REGISTRATION NUMBERS: PACTR201311000621110 and DOH-27-0614-4728; Pre-results.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Breast Feeding , HIV Infections/prevention & control , Infant Health , Infant Mortality , Infectious Disease Transmission, Vertical/prevention & control , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Anti-Bacterial Agents/adverse effects , Anti-HIV Agents/adverse effects , Anti-HIV Agents/therapeutic use , Cause of Death , Diarrhea/epidemiology , Female , Growth Disorders/epidemiology , HIV , HIV Infections/epidemiology , HIV Infections/transmission , HIV Infections/virology , Humans , Incidence , Infant , Male , Morbidity , Mothers , Pneumonia/epidemiology , Pregnancy , Pregnancy Complications, Infectious/virology , Research Design , Trimethoprim, Sulfamethoxazole Drug Combination/adverse effects
6.
South Afr J HIV Med ; 17(1): 444, 2016.
Article in English | MEDLINE | ID: mdl-29568605

ABSTRACT

INTRODUCTION: Limited information is available on the usefulness of the PIMA™ analyser in predicting antiretroviral treatment eligibility and outcome in a primary healthcare clinic setting in disadvantaged communities in KwaZulu-Natal, South Africa. MATERIALS AND METHODS: The study was conducted under the eThekwini Health Unit, Durban, KwaZulu-Natal. Comparison of the enumeration of CD4+ T-cells in 268 patients using the PIMA™ analyser and the predicate National Health Laboratory Services (NHLS) was undertaken during January to July 2013. Bland-Altman analysis to calculate bias and limits of agreement, precision and levels of clinical misclassification at various CD4+ T-cell count thresholds was performed. RESULTS: There was high precision of the PIMA™ control bead cartridges with low and normal CD4+ T-cell counts using three different PIMA™ analysers (%CV < 5). Under World Health Organization (WHO) guidelines (≤ 500 cells/mm3), the sensitivity of the PIMA™ analyser was 94%, specificity 78% and positive predictive value (PPV) 95%. There were 24 (9%) misclassifications, of which 13 were false-negative in whom the mean bias was 149 CD4+ T-cells/mm3. Most (87%) patients returned for their CD4 test result but only 67% (110/164) of those eligible (≤ 350 cells/mm3) were initiated on antiretroviral therapy (ART) with a time to treatment of 49 days (interquartile range [IQR], 42-64 days). CONCLUSION: There was adequate agreement between PIMA™ analyser and predicate NHLS CD4+ T-cell count enumeration (≤ 500 cells/mm3) in adult HIV-positive individuals. The high PPV, sensitivity and acceptable specificity of the PIMA™ analyser technology lend it as a reliable tool in predicting eligibility and rapid linkage to care in ART programmes.

7.
Article in English | AIM (Africa) | ID: biblio-1272210

ABSTRACT

Introduction: Limited information is available on the usefulness of the PIMATM analyser in predicting antiretroviral treatment eligibility and outcome in a primary healthcare clinic setting in disadvantaged communities in KwaZulu-Natal; South Africa.Materials and methods: The study was conducted under the eThekwini Health Unit; Durban; KwaZulu-Natal. Comparison of the enumeration of CD4+ T-cells in 268 patients using the PIMATM analyser and the predicate National Health Laboratory Services (NHLS) was undertaken during January to July 2013. Bland-Altman analysis to calculate bias and limits of agreement; precision and levels of clinical misclassification at various CD4+ T-cell count thresholds was performed.Results: There was high precision of the PIMATM control bead cartridges with low and normal CD4+ T-cell counts using three different PIMATM analysers (%CV 5). Under World Health Organization (WHO) guidelines (


Subject(s)
Anti-Retroviral Agents , HIV Infections/therapy , Potassium Iodide
8.
J Acquir Immune Defic Syndr ; 60(2): 124-7, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-22362152

ABSTRACT

The Centre for the AIDS Program of Research in South Africa 004 trial demonstrated reduction of sexual HIV-1 acquisition in women using a vaginal microbicide containing tenofovir. A better understanding of the consequences of antiretroviral-containing microbicides for immune responses in individuals with intercurrent HIV-1 infection is needed for future trials combining the use of microbicides with HIV-1 vaccines. Investigation of immune responses in women who acquired HIV-1 although using tenofovir gel showed significantly higher (P = 0.01) Gag-specific IFNγ+ CD4+ T-cell responses. The use of tenofovir-containing gel around the time of infection can modulate HIV-1 immunity, and these immunological changes need to be considered in future trials combining vaccines and microbicides.


Subject(s)
Adenine/analogs & derivatives , Anti-HIV Agents/administration & dosage , Anti-Infective Agents/administration & dosage , CD4-Positive T-Lymphocytes/immunology , HIV Infections/prevention & control , HIV-1/immunology , Interferon-gamma/metabolism , Organophosphonates/administration & dosage , Adenine/administration & dosage , Adult , Female , HIV Infections/immunology , HIV Infections/virology , Humans , South Africa , Tenofovir , Vaginal Creams, Foams, and Jellies/administration & dosage
9.
Clin Infect Dis ; 54(2): 294-302, 2012 Jan 15.
Article in English | MEDLINE | ID: mdl-22100578

ABSTRACT

BACKGROUND: Interleukin-10 (IL-10) is a potent immunoregulatory cytokine. IL-10-promoter polymorphisms have been shown to affect human immunodeficiency virus type 1 (HIV-1) clinical outcomes but the underlying mechanisms are poorly understood. METHODS: We investigated the relationship between IL-10-promoter variants, plasma cytokine levels, immune responses and markers of disease outcome in antiretroviral-naïve HIV-1 chronically infected individuals from South Africa. Two IL-10-promoter single nucleotide polymorphisms (SNPs) were genotyped in 451 participants. Baseline plasma levels of select cytokines were measured for 112 individuals. Viral load, CD4(+) T-cell counts and HIV-1-specific interferon-gamma CD8(+) T-cell immune responses were measured at baseline. CD4(+) T-cell counts were measured longitudinally and rates of CD4(+) T-cell decline computed for 300 study subjects. RESULTS: The minor IL-10-1082G and -592A variants occurred at frequencies of 0.31 and 0.34, respectively. The -592AA genotype associated significantly with attenuated loss of CD4(+) T cells (P = .0496). Individuals possessing -1082GG had significantly higher IL-10 levels compared to -1082AA/AG (P = .0006). The -592AA genotype was associated with greater breadth of virus-specific CD8(+) T-cell responses compared to CC and CA (P = .002 and .004 respectively). CONCLUSIONS: IL-10-promoter variants may influence the rate of HIV-1 disease progression by regulating IL-10 levels and the breadth of CD8(+) T-cell immune responses.


Subject(s)
HIV Infections/immunology , HIV-1/immunology , Interleukin-10/genetics , T-Lymphocytes, Cytotoxic/immunology , Adult , CD4 Lymphocyte Count , Female , Genotype , HIV Infections/blood , HIV Infections/genetics , HIV Infections/virology , Humans , Interferon-gamma/genetics , Interferon-gamma/immunology , Interleukin-10/blood , Interleukin-10/immunology , Male , Polymorphism, Single Nucleotide , Promoter Regions, Genetic , Statistics, Nonparametric , Viral Load
10.
J Infect Dis ; 203(6): 803-9, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21257739

ABSTRACT

BACKGROUND: The HLA class II molecules play a central role in the generation of human immunodeficiency virus (HIV)-specific CD4(+) T-helper cells, which are critical for the induction of cytotoxic CD8(+) T cell responses. However, little is known about the impact of HLA class II alleles on HIV disease progression. METHODS: In this study we investigated the effect of HLA class II alleles on HIV disease outcome and HIV-specific T cell responses in a cohort of 426 antiretroviral therapy-naive, HIV-1 clade C-infected, predominantly female black South Africans. RESULTS: The HLA class II allele DRB1*1303 was independently associated with lower plasma viral loads in this population (P = .02), an association that was confirmed in a second cohort of 1436 untreated, HIV-1 clade B-infected, male European Americans, suggesting that DRB1*1303-mediated protection is independent of ethnicity, sex, and viral clade. Interestingly, DRB1*1303 carriage was not associated with an increased frequency of interferon (IFN) γ-positive HIV-specific CD4(+) T cell responses. CONCLUSIONS: These data demonstrate the independent effect of an HLA class II allele, DRB1*1303, on HIV disease progression, in the absence of increased IFN-γ-positive HIV-specific CD4(+) T cell frequencies, suggesting that the protective activity of DRB1*1303 may be mediated via an alternative mechanism.


Subject(s)
HIV Infections/genetics , HIV Infections/immunology , HIV-1 , HLA-DR Antigens/genetics , Viral Load , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cohort Studies , Cytokines/blood , Female , Gene Frequency , Genotype , HIV Infections/blood , HIV-1/classification , HIV-1/genetics , HIV-1/immunology , HLA-DRB1 Chains , Humans , Male , Proportional Hazards Models , South Africa , Treatment Outcome
12.
Virology ; 405(2): 483-91, 2010 Sep 30.
Article in English | MEDLINE | ID: mdl-20638093

ABSTRACT

HIV-1 specific HLA-B-restricted CD8+ T cell responses differ from HLA-C-restricted responses in antiviral effectiveness. To investigate possible reasons for these differences, we characterized the frequency and polyfunctionality of immmunodominant HLA-B*57/B5801- and HLA-Cw*07-restricted CD8+ T cells occurring concurrently in nine study subjects assessing IFN-gamma, TNF-alpha, IL-2, MIP-1beta, and CD107a by flow cytometry and analyzed sequence variation in targeted epitopes. HLA-B*57/5801 and HLA-Cw*07 restricted CD8+ T cells did not differ significantly in polyfunctionality (p=0.84). Possession of three or more functions correlated positively with CD4+ T cell counts (r=0.85; p=0.006) and monofunctional CD8+ T cells inversely correlated with CD4 cell counts (r=-0.79; p=0.05). There were no differences in polyfunctionality of CD8+ T cells specific to wildtype versus mutated epitopes. These results suggest that loss of polyfunctionality and increase in monofunctional HIV-1-specific CD8+ T cells are associated with disease progression independent of restricting HLA allele. Furthermore, sequence variation does not appear to significantly impact CD8+ T cell polyfunctionality in chronic HIV-1 infection.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , HIV Infections/immunology , HLA-B Antigens/immunology , HLA-C Antigens/immunology , Immunodominant Epitopes/immunology , Adult , Amino Acid Sequence , CD4 Lymphocyte Count , CD8-Positive T-Lymphocytes/chemistry , CD8-Positive T-Lymphocytes/metabolism , Chronic Disease , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Epitopes, T-Lymphocyte/metabolism , Female , HIV Infections/virology , HIV-1/immunology , HLA-B Antigens/chemistry , HLA-B Antigens/genetics , HLA-B Antigens/metabolism , HLA-C Antigens/genetics , HLA-C Antigens/metabolism , Humans , Male , Middle Aged , Molecular Sequence Data , Mutation , Viral Load
13.
Clin Infect Dis ; 49(6): 956-64, 2009 Sep 15.
Article in English | MEDLINE | ID: mdl-19663693

ABSTRACT

BACKGROUND: The extent to which immunologic and clinical biomarkers influence human immunodeficiency virus type 1 (HIV-1) infection outcomes remains incompletely characterized, particularly for non-B subtypes. On the basis of data supporting in vitro HIV-1 protein-specific CD8 T lymphocyte responses as correlates of immune control in cross-sectional studies, we assessed the relationship of these responses, along with established HIV-1 biomarkers, with rates of CD4 cell count decrease in individuals infected with HIV-1 subtype C. METHODS: Bivariate and multivariate mixed-effects models were used to assess the relationship of baseline CD4 cell count, plasma viral load, human leukocyte antigen (HLA) class I alleles, and HIV-1 protein-specific CD8 T cell responses with the rate of CD4 cell count decrease in a longitudinal population-based cohort of 300 therapy-naive, chronically infected adults with baseline CD4 cell counts >200 cells/mm(3) and plasma viral loads >500 copies/mL over a median of 25 months of follow-up. RESULTS: In bivariate analyses, baseline CD4 cell count, plasma viral load, and possession of a protective HLA allele correlated significantly with the rate of CD4 cell count decrease. No relationship was observed between HIV-1 protein-specific CD8 T cell responses and CD4 cell count decrease. Results from multivariate models incorporating baseline CD4 cell counts (201-350 vs >350 cells/mm(3)), plasma viral load (< or =100,000 vs >100,000 copies/mL), and HLA (protective vs not protective) yielded the ability to discriminate CD4 cell count decreases over a 10-fold range. The fastest decrease was observed among individuals with CD4 cell counts >350 cells/mm(3) and plasma viral loads >100,000 copies/mL with no protective HLA alleles (-59 cells/mm(3) per year), whereas the slowest decrease was observed among individuals with CD4 cell counts 201-350 cells/mm(3), plasma viral loads < or =100,000 copies/mL, and a protective HLA allele (-6 cells/mm(3) per year). CONCLUSIONS: The combination of plasma viral load and HLA class I type, but not in vitro HIV-1 protein-specific CD8 T cell responses, differentiates rates of CD4 cell count decrease in patients with chronic subtype-C infection better than either marker alone.


Subject(s)
CD4 Lymphocyte Count , HIV Infections/immunology , HIV Infections/virology , HIV-1 , HLA Antigens , Viral Load , Adult , Alleles , Biomarkers/blood , CD4-CD8 Ratio , CD8-Positive T-Lymphocytes/immunology , Cohort Studies , Female , HLA Antigens/genetics , Humans , Longitudinal Studies , Male , Multivariate Analysis , Predictive Value of Tests , South Africa
15.
J Virol ; 81(7): 3667-72, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17251285

ABSTRACT

To better understand relationships between CD8+ T-cell specificity and the immune control of human immunodeficiency virus type 1 (HIV-1), we analyzed the role of HLA-B*13, an allele associated with low viremia, in a cohort of 578 C clade-infected individuals in Durban, South Africa. Six novel B*13-restricted cytotoxic T lymphocyte epitopes were defined from analyses of 37 B*13-positive subjects, including three Gag epitopes. These B*13-restricted epitopes contribute to a broad Gag-specific CD8+ response that is associated with the control of viremia. These data are consistent with data from studies of other HLA-class I alleles associated with HIV control that have shown that the targeting of multiple Gag epitopes is associated with relative suppression of viremia.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Epitopes, T-Lymphocyte/immunology , Gene Products, gag/immunology , HIV-1/immunology , HLA-B Antigens/immunology , Amino Acid Sequence , CD8-Positive T-Lymphocytes/chemistry , Gene Products, gag/genetics , HLA-B Antigens/chemistry , HLA-B13 Antigen , Humans , Molecular Sequence Data , Mutation/genetics
16.
Nat Med ; 13(1): 46-53, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17173051

ABSTRACT

Selection of T-cell vaccine antigens for chronic persistent viral infections has been largely empirical. To define the relationship, at the population level, between the specificity of the cellular immune response and viral control for a relevant human pathogen, we performed a comprehensive analysis of the 160 dominant CD8(+) T-cell responses in 578 untreated HIV-infected individuals from KwaZulu-Natal, South Africa. Of the HIV proteins targeted, only Gag-specific responses were associated with lowering viremia. Env-specific and Accessory/Regulatory protein-specific responses were associated with higher viremia. Increasing breadth of Gag-specific responses was associated with decreasing viremia and increasing Env breadth with increasing viremia. Association of the specific CD8(+) T-cell response with low viremia was independent of HLA type and unrelated to epitope sequence conservation. These population-based data, suggesting the existence of both effective immune responses and responses lacking demonstrable biological impact in chronic HIV infection, are of relevance to HIV vaccine design and evaluation.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , HIV Infections/metabolism , Viral Load , Viral Proteins/metabolism , Adult , Female , Gene Products, env/metabolism , Gene Products, gag/metabolism , HIV Infections/immunology , HIV Infections/virology , HLA Antigens/metabolism , Humans , Male , South Africa , Viremia/immunology , Viremia/metabolism
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