Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters

Country/Region as subject
Publication year range
1.
BMC Infect Dis ; 20(1): 508, 2020 Jul 14.
Article in English | MEDLINE | ID: mdl-32664854

ABSTRACT

BACKGROUND: Increased coagulation biomarkers are associated with poor outcomes among people living with HIV (PLHIV). There are few data available from African cohorts demonstrating the effect of antiretroviral therapy (ART) on coagulation biomarkers. METHODS: From March 2014 to October 2014, ART-naĆÆve PLHIV initiating non-nucleoside reverse transcriptase inhibitor-based ART were recruited from seven clinics in western Kenya and followed for up to 12 months. Demographics, clinical history and blood specimens were collected. Logistic regression models adjusted for intrasite clustering examined associations between HIV viral load and D-Dimer at baseline. Mixed linear effects models were used to estimate mean change from baseline to 6 months overall, and by baseline viral load, sex and TB status at enrollment. Mean change in D-dimer at 6 months is reported on the log10 scale and as percentage change from baseline. RESULTS: Among 611 PLHIV enrolled, 66% were female, median age was 34 years (interquartile range (IQR) 29-43 years), 31 (5%) participants had tuberculosis and median viral load was 113,500 copies/mL (IQR: 23,600-399,000). At baseline, 311 (50.9%) PLHIV had elevated D-dimer (> 500 ng/mL) and median D-dimer was 516.4 ng/mL (IQR: 302.7-926.6) (log baseline D-dimer: 2.7, IQR: 2.5-3.0). Higher baseline D-dimer was significantly associated with higher viral load (pĀ < 0.0001), female sex (pĀ = 0.02) and tuberculosis (pĀ = 0.02). After 6 months on ART, 518 (84.8%) PLHIV had achieved viral load < 1000 copies/mL and median D-dimer was 390.0 (IQR: 236.6-656.9) (log D-dimer: 2.6, IQR: 2.4-2.8). Mean change in log D-dimer from baseline to 6 months was - 0.12 (95%CI -0.15, - 0.09) (pĀ < 0.0001) indicating at 31.3% decline (95%CI -40.0, - 23.0) in D-dimer levels over the first 6 months on ART. D-dimer decline after ART initiation was significantly greater among PLHIV with tuberculosis at treatment initiation (- 172.1, 95%CI -259.0, - 106.3; pĀ < 0.0001) and those with log viral load > 6.0 copies/mL (- 91.1, 95%CI -136.7, - 54.2; pĀ < 0.01). CONCLUSIONS: In this large Kenyan cohort of PLHIV, women, those with tuberculosis and higher viral load had elevated baseline D-dimer. ART initiation and viral load suppression among ART-naĆÆve PLHIV in Kenya were associated with significant decrease in D-dimer at 6 months in this large African cohort.


Subject(s)
AIDS-Related Opportunistic Infections/drug therapy , AIDS-Related Opportunistic Infections/epidemiology , Anti-HIV Agents/therapeutic use , Fibrin Fibrinogen Degradation Products/analysis , Reverse Transcriptase Inhibitors/therapeutic use , Tuberculosis/epidemiology , AIDS-Related Opportunistic Infections/mortality , Adult , Biomarkers/analysis , Biomarkers/metabolism , Blood Coagulation/drug effects , Comorbidity , Female , Fibrin Fibrinogen Degradation Products/metabolism , Follow-Up Studies , Humans , Kenya/epidemiology , Male , Prospective Studies , Sex Factors , Viral Load/drug effects , Young Adult
2.
BMC Health Serv Res ; 18(1): 17, 2018 Jan 10.
Article in English | MEDLINE | ID: mdl-29321026

ABSTRACT

BACKGROUND: The recent scale-up of prevention of mother-to-child transmission of HIV (PMTCT) services has rapidly accelerated antiretroviral therapy (ART) uptake among pregnant and postpartum women in sub-Saharan Africa. The Mother and Infant Retention for Health (MIR4Health) study evaluates the impact of a combination intervention administered by trained lay health workers to decrease attrition among HIV-positive women initiating PMTCT services and their infants through 6 months postpartum. METHODS: This was a qualitative study nested within the MIR4Health trial. MIR4Health was conducted at 10 health facilities in Nyanza, Kenya from September 2013 to September 2015. The trial intervention addressed behavioral, social, and structural barriers to PMTCT retention and included: appointment reminders via text and phone calls, follow-up and tracking for missed clinic visits, PMTCT health education at home visits and during clinic visits, and retention and adherence support and counseling. All interventions were administered by lay health workers. We describe results of a nested small qualitative inquiry which conducted two focus groups to assess the experiences and perceptions of lay health workers administering the interventions. Discussions were recorded and simultaneously transcribed and translated into English. Data were analyzed using framework analysis approach. RESULTS: Study findings show lay health workers played a critical role supporting mothers in PMTCT services across a range of behavioral, social, and structural domains, including improved communication and contact, health education, peer support, and patient advocacy and assistance. Findings also identified barriers to the uptake and implementation of the interventions, such as concerns about privacy and stigma, and the limitations of the healthcare system including healthcare worker attitudes. Overall, study findings indicate that lay health workers found the interventions to be feasible, acceptable, and well received by clients. CONCLUSIONS: Lay health workers played a fundamental role in supporting mothers engaged in PMTCT services and provided valuable feedback on the implementation of PMTCT interventions. Future interventions must include strategies to ensure client privacy, decrease stigma within communities, and address the practical limitations of health systems. This study adds important insight to the growing body of research on lay health worker experiences in HIV and PMTCT care. TRIAL REGISTRATION: Clinicaltrials.gov NCT01962220 .


Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections/transmission , Infectious Disease Transmission, Vertical/prevention & control , Maternal-Child Health Services , Mothers/psychology , Patient Acceptance of Health Care/statistics & numerical data , Pregnancy Complications, Infectious/drug therapy , Adult , Communication , Female , Focus Groups , HIV Infections/prevention & control , HIV Infections/psychology , Humans , Infant , Infant, Newborn , Kenya , Maternal-Child Health Services/organization & administration , Postpartum Period/psychology , Pregnancy , Pregnancy Complications, Infectious/psychology , Qualitative Research , Social Stigma , Young Adult
3.
J Immunol ; 191(5): 2164-73, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23894197

ABSTRACT

Mucosal Th17 cells maintain the gut epithelial barrier and prevent invasion by luminal bacteria through a delicate balance of immunosuppressive and proinflammatory functions. HIV infection is characterized by mucosal Th17 depletion, microbial translocation, and immune activation. Therefore, we assessed the function of blood and sigmoid Th17 cells during both early and chronic HIV infection, as well as the impact of short- and long-term antiretroviral therapy. Th17 cells were defined as IL-17a(+) CD4 T cells, and their functional capacity was assessed by the coproduction of the inflammatory cytokines IL-22, TNF-α, and IFN-ƎĀ³, as well as the immunoregulatory cytokine IL-10. Gut Th17 cells had a much greater capacity to produce proinflammatory cytokines than did those from the blood, but this capacity was dramatically reduced from the earliest stages of HIV infection. Immunoregulatory skewing of mucosal Th17 cell function, characterized by an increased IL-10/TNF-α ratio, was uniquely seen during early HIV infection and was independently associated with reduced systemic immune activation. Antiretroviral therapy rapidly restored mucosal Th17 cell numbers; however, normalization of mucosal Th17 function, microbial translocation, and mucosal/systemic immune activation was much delayed. These findings emphasize that strategies to preserve or to more rapidly restore mucosal Th17 function may have important therapeutic benefit.


Subject(s)
HIV Infections/immunology , Intestinal Mucosa/immunology , Th17 Cells/immunology , Adult , Anti-Retroviral Agents/therapeutic use , Female , Flow Cytometry , HIV Infections/drug therapy , Humans , Male , Middle Aged
4.
J Immunol ; 187(11): 6032-42, 2011 Dec 01.
Article in English | MEDLINE | ID: mdl-22048765

ABSTRACT

The HIV pandemic disproportionately affects women, with most infections acquired through receptive vaginal sex. Although the target cells by which HIV establishes infection in the female genital tract remain poorly defined, it is known that immune activation results in CD4(+) T cells with enhanced susceptibility, as does expression of the mucosal integrin α4Ɵ7 and the HIV coreceptor CCR5. Blood and cervical cytobrush specimens were collected from female sex workers (FSWs) in Nairobi, Kenya. Genital infection diagnostics were performed, T cell populations were defined by multiparameter flow cytometry based on their expression of surface receptors relevant to mucosal homing and/or HIV acquisition, and cytokine production was assayed by intracellular cytokine staining. The integrin α4Ɵ7 was expressed on 26.0% of cervical CD4(+) T cells, and these cells were more likely to express both the HIV coreceptor CCR5 (p < 0.0001) and the early activation marker CD69 (p < 0.0001) but not CXCR4 (p = 0.34). Cervical Th17 frequencies were enhanced compared with blood (7.02 versus 1.24%; p < 0.0001), and cervical IL-17A(+) CD4(+) T cells preferentially coexpressed α4Ɵ7 and CCR5. Expression of IFN-ƎĀ³ and IL-22 was greater in cervical Th17 cells than in blood Th17 cells. In keeping with the hypothesis that these cells are preferential HIV targets, gp120 preferentially bound CCR5(+) cervical T cells, and cervical Th17 cells were almost completely depleted in HIV(+) FSWs compared with HIV(-) FSWs. In summary, a subset of Th17 CD4(+) T cells in the cervical mucosa coexpresses multiple HIV susceptibility markers; their dramatic depletion after HIV infection suggests that these may serve as key target cells during HIV transmission.


Subject(s)
Cervix Uteri/immunology , HIV Infections/transmission , Immunity, Mucosal/immunology , T-Lymphocyte Subsets/immunology , Th17 Cells/immunology , Adult , Biomarkers/analysis , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , Cell Separation , Cervix Uteri/cytology , Cervix Uteri/metabolism , Cytokines/analysis , Cytokines/biosynthesis , Cytokines/immunology , Disease Susceptibility/immunology , Female , Flow Cytometry , HIV Infections/immunology , HIV Infections/metabolism , Humans , Integrins/analysis , Integrins/biosynthesis , Integrins/immunology , Interferon-gamma/analysis , Interferon-gamma/biosynthesis , Interferon-gamma/immunology , Interleukin-17/analysis , Interleukin-17/biosynthesis , Interleukin-17/immunology , Receptors, CCR5/analysis , Receptors, CCR5/biosynthesis , Receptors, CCR5/immunology , Reverse Transcriptase Polymerase Chain Reaction , T-Lymphocyte Subsets/metabolism , T-Lymphocyte Subsets/virology , Th17 Cells/metabolism , Th17 Cells/virology
5.
AIDS Res Hum Retroviruses ; 39(2): 57-67, 2023 02.
Article in English | MEDLINE | ID: mdl-36401361

ABSTRACT

Nationally representative surveys provide an opportunity to assess trends in recent human immunodeficiency virus (HIV) infection based on assays for recent HIV infection. We assessed HIV incidence in Kenya in 2018 and trends in recent HIV infection among adolescents and adults in Kenya using nationally representative household surveys conducted in 2007, 2012, and 2018. To assess trends, we defined a recent HIV infection testing algorithm (RITA) that classified as recently infected (<12 months) those HIV-positive participants that were recent on the HIV-1 limiting antigen (LAg)-avidity assay without evidence of antiretroviral use. We assessed factors associated with recent and long-term (≥12 months) HIV infection versus no infection using a multinomial logit model while accounting for complex survey design. Of 1,523 HIV-positive participants in 2018, 11 were classified as recent. Annual HIV incidence was 0.14% in 2018 [95% confidence interval (CI) 0.057-0.23], representing 35,900 (95% CI 16,300-55,600) new infections per year in Kenya among persons aged 15-64 years. The percentage of HIV infections that were determined to be recent was similar in 2007 and 2012 but fell significantly from 2012 to 2018 [adjusted odds ratio (aOR) = 0.31, p < .001]. Compared to no HIV infection, being aged 25-34 versus 35-64 years (aOR = 4.2, 95% CI 1.4-13), having more lifetime sex partners (aOR = 5.2, 95% CI 1.6-17 for 2-3 partners and aOR = 8.6, 95% CI 2.8-26 for ≥4 partners vs. 0-1 partners), and never having tested for HIV (aOR = 4.1, 95% CI 1.5-11) were independently associated with recent HIV infection. Although HIV remains a public health priority in Kenya, HIV incidence estimates and trends in recent HIV infection support a significant decrease in new HIV infections from 2012 to 2018, a period of rapid expansion in HIV diagnosis, prevention, and treatment.


Subject(s)
HIV Infections , HIV Seropositivity , Adult , Adolescent , Humans , Kenya/epidemiology , Incidence , Sexual Partners
6.
PLoS One ; 18(6): e0275560, 2023.
Article in English | MEDLINE | ID: mdl-37363921

ABSTRACT

BACKGROUND: We examined the epidemiology and transmission potential of HIV population viral load (VL) in 12 sub-Saharan African countries. METHODS: We analyzed data from Population-based HIV Impact Assessments (PHIAs), large national household-based surveys conducted between 2015 and 2019 in Cameroon, Cote d'Ivoire, Eswatini, Kenya, Lesotho, Malawi, Namibia, Rwanda, Tanzania, Uganda, Zambia, and Zimbabwe. Blood-based biomarkers included HIV serology, recency of HIV infection, and VL. We estimated the number of people living with HIV (PLHIV) with suppressed viral load (<1,000 HIV-1 RNA copies/mL) and with unsuppressed viral load (viremic), the prevalence of unsuppressed HIV (population viremia), sex-specific HIV transmission ratios (number female incident HIV-1 infections/number unsuppressed male PLHIV per 100 persons-years [PY] and vice versa) and examined correlations between a variety of VL metrics and incident HIV. Country sample sizes ranged from 10,016 (Eswatini) to 30,637 (Rwanda); estimates were weighted and restricted to participants 15 years and older. RESULTS: The proportion of female PLHIV with viral suppression was higher than that among males in all countries, however, the number of unsuppressed females outnumbered that of unsuppressed males in all countries due to higher overall female HIV prevalence, with ratios ranging from 1.08 to 2.10 (median: 1.43). The spatial distribution of HIV seroprevalence, viremia prevalence, and number of unsuppressed adults often differed substantially within the same countries. The 1% and 5% of PLHIV with the highest VL on average accounted for 34% and 66%, respectively, of countries' total VL. HIV transmission ratios varied widely across countries and were higher for male-to-female (range: 2.3-28.3/100 PY) than for female-to-male transmission (range: 1.5-10.6/100 PY). In all countries mean log10 VL among unsuppressed males was higher than that among females. Correlations between VL measures and incident HIV varied, were weaker for VL metrics among females compared to males and were strongest for the number of unsuppressed PLHIV per 100 HIV-negative adults (R2 = 0.92). CONCLUSIONS: Despite higher proportions of viral suppression, female unsuppressed PLHIV outnumbered males in all countries examined. Unsuppressed male PLHIV have consistently higher VL and a higher risk of transmitting HIV than females. Just 5% of PLHIV account for almost two-thirds of countries' total VL. Population-level VL metrics help monitor the epidemic and highlight key programmatic gaps in these African countries.


Subject(s)
Anti-HIV Agents , HIV Infections , Adult , Humans , Male , Female , HIV Infections/drug therapy , Viremia/drug therapy , Viral Load , Seroepidemiologic Studies , Lesotho , Zimbabwe , Anti-HIV Agents/therapeutic use
7.
J Immunol ; 185(1): 498-506, 2010 Jul 01.
Article in English | MEDLINE | ID: mdl-20519650

ABSTRACT

We examined the role of CD4(+) T cell IL-21 production in viral control of HIV infection. HIV-infected individuals had greater circulating IL-21-producing CD4(+) T cells in blood compared with uninfected volunteers. HIV-specific IL-21-producing CD4(+) T cells were detected in blood during untreated acute and chronic HIV infection, and elevated frequencies of these cells correlated with relative viral control. These cells had an effector memory or end effector phenotype and expressed CXCR5. HIV-specific CD8(+) T cells exhibited high levels of IL-21R, indicating sensitivity to IL-21. Low or aviremic long-term nonprogressors, however, showed absent or low HIV-specific IL-21 CD4(+) T cells, but more easily detectable HIV-specific IL-2-producing CD4(+) T cells, suggesting changing requirements for particular gamma-chain cytokines depending on Ag abundance. Thus, IL-21-producing CD4(+) T cells are induced in viremic HIV infection and likely contribute to viral control by affecting CD8(+) T cell maintenance.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , Epitopes, T-Lymphocyte/immunology , HIV Infections/immunology , HIV Infections/virology , HIV-1/immunology , Interleukins/biosynthesis , Lymphocyte Activation/immunology , Acute Disease , CD4-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/virology , Chronic Disease , Disease Progression , HIV Infections/pathology , HIV-1/genetics , Immunologic Memory , Immunophenotyping , Viral Load/immunology
9.
J Acquir Immune Defic Syndr ; 80(1): 56-63, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30399035

ABSTRACT

BACKGROUND: Retention of mothers and infants across the prevention of mother-to-child HIV transmission (PMTCT) continuum remains challenging. We assessed the effectiveness of a lay worker administered combination intervention compared with the standard of care (SOC) on mother-infant attrition. METHODS: HIV-positive pregnant women starting antenatal care at 10 facilities in western Kenya were randomized using simple randomization to receive individualized health education, retention/adherence support, appointment reminders, and missed visit tracking vs. routine care per guidelines. The primary endpoint was attrition of mother-infant pairs at 6 months postpartum. Attrition was defined as the proportion of mother-infant pairs not retained in the clinic at 6 months postpartum because of mother or infant death or lost to follow-up. Intent-to-treat analysis was used to assess the difference in attrition. This trial is registered with ClinicalTrials.gov; NCT01962220. RESULTS: From September 2013 to June 2014, 361 HIV-positive pregnant women were screened, and 340 were randomized to the intervention (n = 170) or SOC (n = 170). Median age at enrollment was 26 years (interquartile range 22-30); median gestational age was 24 weeks (interquartile range 17-28). Overall attrition of mother-infant pairs was 23.5% at 6 months postpartum. Attrition was significantly lower in the intervention arm compared with SOC (18.8% vs. 28.2%, relative risk (RR) = 0.67, 95% confidence interval: 0.45 to 0.99, P = 0.04). Overall, the proportion of mothers who were retained and virally suppressed (<1000 copies/mL) at 6 months postpartum was 54.4%, with no difference between study arms. CONCLUSIONS: Provision of a combination intervention by lay counselors can decrease attrition along the PMTCT cascade in low-resource settings.


Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , Infectious Disease Transmission, Vertical/prevention & control , Mothers , Pregnancy Complications, Infectious/drug therapy , Prenatal Care , Adult , Counselors , Female , Health Care Surveys , Health Education , Humans , Infant , Infant, Newborn , Kenya/epidemiology , Male , Mothers/education , Mothers/psychology , Outcome Assessment, Health Care , Pregnancy , Pregnancy Complications, Infectious/prevention & control , Prenatal Care/methods , Reminder Systems , Social Support
10.
J Assoc Nurses AIDS Care ; 27(3): 322-30, 2016.
Article in English | MEDLINE | ID: mdl-27086191

ABSTRACT

Given the burden of HIV and the critical shortage of health workers in Kenya, in 2011 the National AIDS and STI Control Program recommended shifting HIV care and treatment tasks to nurses in settings without physicians and clinical officers in order to decentralize and scale-up HIV services. In September 2013, ICAP at Columbia University conducted a survey with nurses in four health facilities in eastern Kenya to assess preparedness for task shifting. Findings indicated gaps in nurses' training, perceived competency, and practice in HIV care and treatment. Further investment in nurse capacity building is needed to bridge the gaps and prepare more nurses to provide high-quality, comprehensive HIV care and treatment services to curb the epidemic in Kenya.


Subject(s)
Anti-HIV Agents/administration & dosage , Clinical Competence , HIV Infections/drug therapy , HIV Infections/nursing , Nursing Staff/education , Practice Patterns, Nurses' , Cross-Sectional Studies , Humans , Inservice Training , Patient Acceptance of Health Care , Primary Health Care , Process Assessment, Health Care , Workforce
11.
J Acquir Immune Defic Syndr ; 72 Suppl 2: S137-44, 2016 08 01.
Article in English | MEDLINE | ID: mdl-27355501

ABSTRACT

BACKGROUND: Effective retention of HIV-infected mothers and their infants is fraught with multiple challenges, resulting in loss across the continuum of prevention of mother-to-child HIV transmission (PMTCT) care and missed opportunities to offer life-saving HIV prevention and treatment. METHODS: The Mother Infant Retention for Health study is an individual-randomized study evaluating the effectiveness of active patient follow-up compared with standard of care on the combined outcome of attrition of HIV-infected women and their infants at 6 months postpartum. Lay counselors administered the active patient follow-up package of interventions, including individualized health education, use of flip charts during clinic visits, and at home, phone and short message service appointment reminders, active phone and physical tracking of patients immediately after missed clinic visits, and individualized retention and adherence support. RESULTS: Use of study visits to indicate participant progression along the PMTCT cascade highlights the nature of loss among women and infants in PMTCT care because of issues such as pregnancy complications, infant deaths, and transfer out. Delay in implementation of Option B+, unanticipated slow enrollment, a health-care worker strike, rapid HIV test kit shortages, and changes in national PMTCT guidelines necessitated several modifications to the protocol design and implementation to ensure successful completion of the study. CONCLUSIONS: Flexibility when operationalizing an implementation science study is critical in the context of the shifting landscape in a noncontrolled "real-world" setting. TRIAL REGISTRATION: Clinicaltrials.gov NCT01962220.


Subject(s)
HIV Infections/transmission , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Infectious/drug therapy , Anti-HIV Agents/therapeutic use , Female , Humans , Infant, Newborn , Kenya , Pregnancy
12.
AIDS ; 29 Suppl 2: S129-36, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26102623

ABSTRACT

The centrality of quality as a strategy to achieve impact within the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) has been widely recognized. However, monitoring program quality remains a challenge for many HIV programs, particularly those in resource-limited settings, where human resource constraints and weaker health systems can pose formidable barriers to data collection and interpretation. We describe the practicalities of monitoring quality at scale within a very large multicountry PEPFAR-funded program, based largely at health facilities. The key elements include the following: supporting national programs and strategies; developing a conceptual framework and programmatic model to define quality and guide the provision of high-quality services; attending to program context, as well as program outcomes; leveraging existing and routinely collected data whenever possible; developing additional indicators for judicious use in targeted, in-depth assessments; providing hands-on support for data collection and use at the facility, sub-national, and national levels; utilizing web-based databases for data entry, analysis, and dissemination; and multidisciplinary support from a large team of clinical and strategic information advisors.


Subject(s)
Community Health Services/organization & administration , Delivery of Health Care/organization & administration , HIV Infections/therapy , Health Facility Administration/standards , Health Services Accessibility/organization & administration , Quality Assurance, Health Care/organization & administration , Developing Countries , Directive Counseling , HIV Infections/epidemiology , HIV Infections/prevention & control , Health Facility Administration/trends , Health Services Accessibility/trends , Healthcare Disparities/statistics & numerical data , Humans , International Cooperation , National Health Programs , Program Development , Program Evaluation , Standard of Care
13.
J Acquir Immune Defic Syndr ; 65(5): 517-25, 2014 Apr 15.
Article in English | MEDLINE | ID: mdl-24256632

ABSTRACT

OBJECTIVE: To evaluate if systemic murine malarial infection enhances HIV susceptibility through parasite-induced mucosal immune alterations at sites of HIV sexual exposure. BACKGROUND: Malaria and HIV have a high degree of geographical overlap and interact substantially within coinfected individuals. We used a murine model to test the hypothesis that malaria might also enhance HIV susceptibility at mucosal sites of HIV sexual exposure. METHODS: Female C57/BL6 mice were infected with Plasmodium chabaudi malaria using a standardized protocol. Blood, gastrointestinal tissues, upper and lower genital tract tissues, and iliac lymph nodes were sampled 10 days postinfection, and the expression of putative HIV susceptibility and immune activation markers on T cells was assessed by flow cytometry. RESULTS: P. chabaudi malaria increased expression of mucosal homing integrin α4Ɵ7 on blood CD4 and CD8 T cells, and these α4Ɵ7 T cells had significantly increased co-expression of both CCR5 and CD38. In addition, malaria increased expression of the HIV co-receptor CCR5 on CD4 T cells from the genital tract and gut mucosa as well as mucosal T-cell expression of the immune activation markers CD38, Major Histocompatibility Complex -II (MHC-II) and CD69. CONCLUSIONS: Systemic murine malarial infection induced substantial upregulation of the mucosal homing integrin α4Ɵ7 in blood as well as gut and genital mucosal T-cell immune activation and HIV co-receptor expression. Human studies are required to confirm these murine findings and to examine whether malarial infection enhances the sexual acquisition of HIV.


Subject(s)
Disease Susceptibility , Gastrointestinal Tract/immunology , Genitalia/immunology , HIV Infections/immunology , Immunity, Mucosal , Malaria/immunology , Plasmodium chabaudi/immunology , Animals , Female , Flow Cytometry , Gene Expression Profiling , Lymphocyte Activation , Malaria/complications , Mice , Mice, Inbred C57BL , Receptors, HIV/biosynthesis , T-Lymphocytes/immunology
14.
BMJ Open ; 2(2): e000565, 2012.
Article in English | MEDLINE | ID: mdl-22466157

ABSTRACT

OBJECTIVES: Although antiretroviral therapy (ART) prolongs life and reduces infectiousness, in some contexts, it has been associated with increased sexual risk taking. DESIGN: Retrospective case-control study. SETTING: Nairobi-based dedicated female sex worker (FSW) clinic. PARTICIPANTS: HIV-infected FSWs before and after ART initiation (n=62); HIV-infected and -uninfected control FSWs not starting ART during the same follow-up period (n=40). INTERVENTION: Initiation of ART. PRIMARY OUTCOME MEASURES: Self-reported condom use, client numbers and sexually transmitted infection incidence over the study period (before and after ART initiation in cases). RESULTS: Sexual risk-taking behaviour with casual clients did not increase after ART initiation; condom use increased and sexually transmitted infection incidence decreased in both cases and controls, likely due to successful cohort-wide HIV prevention efforts. CONCLUSIONS: ART provision was not associated with increases in unsafe sex in this FSW population.

15.
AIDS ; 26(2): 167-74, 2012 Jan 14.
Article in English | MEDLINE | ID: mdl-22089379

ABSTRACT

BACKGROUND: Highly active antiretroviral therapy (HAART) dramatically reduces plasma HIV-1 viremia. However, despite completely suppressive HAART, it has been suggested that low-levels of viral replication may persist in the gut mucosa and elsewhere in individuals on long-term HAART. OBJECTIVE: We conducted a double-blind randomized, placebo-controlled trial evaluating whether intensification of HAART in long-term virologically suppressed individuals with raltegravir is associated with a reduction in the level of proviral HIV-1 DNA in CD4(+) T cells in blood and the sigmoid colon (gut). METHODS: Long-term (>4 years) virologically suppressed HIV-infected individuals on standard HAART were randomized 1Ć¢Ā€ĀŠ:Ć¢Ā€ĀŠ1 in a double-blind fashion to receive raltegravir (400 Ć¢Ā€ĀŠmg twice/day) or placebo for 48 weeks. After week 48, all participants were treated with raltegravir to week 96. Blood and sigmoid biopsies were sampled and the frequency of CD4(+) T cells carrying HIV-1 proviral DNA was determined. RESULTS: Twenty-four study patients were recruited. At 48 weeks, no difference was apparent between participants receiving raltegravir or placebo in blood HIV-1 proviral levels (PĆ¢Ā€ĀŠ=Ć¢Ā€ĀŠ0.62), CD4(+) T-cell counts (PĆ¢Ā€ĀŠ=Ć¢Ā€ĀŠ0.25) and gut proviral loads (PĆ¢Ā€ĀŠ=Ć¢Ā€ĀŠ0.74). Similarly, prolonged raltegravir intensification up to week 96 had no further effect on both blood and gut HIV-1 proviral loads and blood CD4(+) T-cell counts. CONCLUSION: In long-term virologically suppressed patients on standard HAART, intensification with raltegravir did not result in further decay of CD4(+) T cells carrying HIV-1 proviral DNA in either the blood or gut after 48 or 96 weeks of therapy, or in any increase in CD4(+) T-cell counts.


Subject(s)
Anti-HIV Agents/administration & dosage , DNA, Viral/drug effects , HIV Infections/drug therapy , HIV-1/drug effects , Intestinal Mucosa/drug effects , Proviruses/drug effects , Pyrrolidinones/administration & dosage , Adult , Antiretroviral Therapy, Highly Active , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/virology , DNA, Viral/blood , Dose-Response Relationship, Drug , Double-Blind Method , Female , HIV Infections/immunology , HIV-1/genetics , HIV-1/isolation & purification , Humans , Intestinal Mucosa/virology , Male , Middle Aged , Prospective Studies , Proviruses/genetics , Raltegravir Potassium , Viral Load , Viremia/drug therapy , Viremia/virology
16.
PLoS One ; 7(8): e43670, 2012.
Article in English | MEDLINE | ID: mdl-22928014

ABSTRACT

BACKGROUND: Identifying the immune correlates of reduced susceptibility to HIV remains a key goal for the HIV vaccine field, and individuals who are HIV-exposed, seronegative (HESN) may offer important clues. Reduced systemic immune activation has been described in HESN individuals. Conversely, pro-inflammatory T cell subsets, particularly CD4+ T cells producing the cytokine IL17 (Th17 cells), may represent a highly susceptible target for HIV infection after sexual exposure. Therefore, we characterized the cellular pro-inflammatory and IL17/IL22 cytokine immune milieu in the genital mucosa and blood of HESN female sex workers (FSWs). METHODS AND RESULTS: Blinded lab personnel characterized basal and mitogen-induced gene and cytokine immune responses in the cervix and blood of HESN FSWs (nĆ¢Ā€ĀŠ=Ć¢Ā€ĀŠ116) and non-FSW controls (nĆ¢Ā€ĀŠ=Ć¢Ā€ĀŠ17) using qPCR and ELISA. IL17 and IL22 production was significantly reduced in both the cervix and blood of HESNs, both in resting cells and after mitogen stimulation. In addition, HESN participants demonstrated blunted production of both pro-inflammatory cytokines and Ɵ-chemokines. DISCUSSION AND CONCLUSIONS: We conclude that HIV exposure without infection was associated with blunted IL17/IL22 and pro-inflammatory responses, both systemically and at the site of mucosal HIV exposure. It will be important for further studies to examine the causal nature of the association and to define the cell subsets responsible for these differences.


Subject(s)
Environmental Exposure , Genitalia, Female/virology , HIV Seronegativity , HIV-1/physiology , Interleukin-17/metabolism , Interleukins/metabolism , Sex Workers , Adult , Cervix Uteri/immunology , Cervix Uteri/metabolism , Cervix Uteri/virology , Female , Gene Expression Regulation/immunology , Genitalia, Female/immunology , Genitalia, Female/metabolism , HIV-1/immunology , Humans , Inflammation/metabolism , Interleukin-17/blood , Interleukin-17/genetics , Interleukins/blood , Interleukins/genetics , Kenya , Middle Aged , Mucous Membrane/immunology , Mucous Membrane/metabolism , Mucous Membrane/virology , Risk , Young Adult , Interleukin-22
18.
Am J Reprod Immunol ; 65(3): 317-24, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21223426

ABSTRACT

Despite tremendous regional and subregional disparities in HIV prevalence around the world, epidemiology consistently demonstrates that black communities have been disproportionately affected by the pandemic. There are many reasons for this, and a narrow focus on socio-behavioural causes may be seen as laying blame on affected communities or individuals. HIV sexual transmission is very inefficient, and a number of biological factors are critical in determining whether an unprotected sexual exposure to HIV results in productive infection. This review will focus on ways in which biology, rather than behaviour, may contribute to regional and racial differences in HIV epidemic spread. Specific areas of focus are viral factors, host genetics, and the impact of co-infections and host immunology. Considering biological causes for these racial disparities may help to destigmatize the issue and lead to new and more effective strategies for prevention.


Subject(s)
HIV Infections/epidemiology , HIV Infections/transmission , HIV-1 , Health Status Disparities , Africa , Black People/statistics & numerical data , Female , Genetic Predisposition to Disease , Geography , HIV Infections/complications , HIV Infections/virology , HIV-1/physiology , Humans , Immunity, Innate/genetics , Immunity, Mucosal , Infections/complications , Male , Minority Health , Prevalence , Racial Groups/genetics , Risk Factors
19.
AIDS ; 25(6): 741-9, 2011 Mar 27.
Article in English | MEDLINE | ID: mdl-21378536

ABSTRACT

OBJECTIVE: Th17 cells play an important role in mucosal defence and repair and are highly susceptible to infection by HIV. Antiretroviral therapy (ART) suppresses HIV viremia and can restore CD4(+) numbers in the blood and gastrointestinal mucosa, but the resolution of systemic inflammation and gut microbial translocation is often incomplete. We hypothesized that this might relate to persistent dysregulation of gut CD4(+) Th17 subsets. METHODS: Blood and sigmoid biopsies were collected from HIV-uninfected men, chronically HIV-infected, ART-naive men, and men on effective ART for more than 4 years. Sigmoid provirus levels were assayed blind to participant status, as were CD4(+) Th17 subsets, systemic markers of microbial translocation, and cellular immune activation. RESULTS: There was minimal CD4(+) Th17 dysregulation in the blood until later stage HIV infection, but gastrointestinal Th17 depletion was apparent much earlier, along with increased plasma markers of microbial translocation. Plasma lipopolysaccharide (LPS) remained elevated despite overall normalization of sigmoid Th17 populations on long-term ART, although there was considerable interindividual variability in Th17 reconstitution. An inverse correlation was observed between plasma LPS levels and gut Th17 frequencies, and higher plasma LPS levels correlated with an increased gut HIV proviral reservoir. CONCLUSION: Sigmoid Th17 populations were preferentially depleted during HIV infection. Despite overall CD4(+) T-cell reconstitution, sigmoid Th17 frequencies after long-term ART were heterogeneous and higher frequencies were correlated with reduced microbial translocation.


Subject(s)
Bacterial Translocation/immunology , Colon, Sigmoid/immunology , HIV Infections/immunology , HIV-1/physiology , Intestinal Mucosa/immunology , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Immunodeficiency Virus/immunology , Th17 Cells/immunology , Adult , Animals , CD4-Positive T-Lymphocytes/immunology , Chlorocebus aethiops , HIV Infections/drug therapy , HIV Infections/pathology , Humans , Intestinal Mucosa/pathology , Intestinal Mucosa/virology , Male , Middle Aged , Simian Acquired Immunodeficiency Syndrome/pathology , Simian Immunodeficiency Virus/pathogenicity
20.
Am J Reprod Immunol ; 63(4): 299-309, 2010 Apr 01.
Article in English | MEDLINE | ID: mdl-20070285

ABSTRACT

PROBLEM: Previously we reported that ovariectomized (OVX) mice receiving estradiol (E) prior to immunization with an attenuated strain of HSV-2 (TK-HSV-2) were not protected. Lack of protection in the E group was because of the inability of TK-HSV-2 to penetrate the thick keratinized epithelium. In this study, we determined the outcome of immunization after the thickening of vaginal epithelium following E-treatment waned. OVX, C57BL/6 mice were given Progesterone (P), E or saline (S) for 3 days and immunized with IVAG TK-HSV-2. METHOD OF STUDY: To determine the time point at which E-treated mice could be successfully immunized, the mice were inoculated with TK-HSV-2 between days 1 and 7 (ED1-ED7) post-E-treatment and challenged with IVAG HSV-2 three weeks later. RESULTS: The level of infection post-immunization correlated with HSV-2-specific IgG antibody level, which correlated with sterile protection. No viral infection was observed in ED1-ED3 groups and no specific antibodies were detected, resulting in no protection. Moderate infection was seen in ED5 group, resulting in low antibody production and non-sterile protection in 87.5% of mice. High antibody titers and sterile protection were observed in all groups that experienced robust infection post-immunization. CONCLUSION: The results show that estradiol leads to limited viral replication and diminished mucosal IgG response, resulting in non-sterile immune protection against genital herpes infection.


Subject(s)
Estradiol/physiology , Herpes Genitalis/immunology , Herpesvirus 2, Human/immunology , Immunoglobulin G/immunology , Virus Replication , Administration, Intravaginal , Animals , Female , Herpes Genitalis/prevention & control , Herpes Genitalis/virology , Immunization , Mice , Mice, Inbred C57BL , Mucous Membrane/immunology
SELECTION OF CITATIONS
SEARCH DETAIL