HIV, hepatitis B and C, and syphilis share common transmission routes of which primarily unsafe sexual contact and injecting drug use are important. Impulsivity is a major factor contributing to this ...transmission risk behavior; however comprehensive studies within female, prison, and Asian populations are scarce. This cross-sectional study aims to delineate the contributions of different aspects of impulsivity to risk behavior, among female inmates living in a prison in Jakarta (N = 214). The relationships between various aspects of impulsivity, risk behaviors and seropositivity were tested using analyses of variance and logistic regression analyses. Motor impulsivity was related to alcohol use, reward-related impulsivity to drug use, and cognitive/goal-directed impulsivity to sexual risk behavior. Finally, goal-directed impulsivity was also directly associated with seropositivity. Specific aspects of impulsivity are associated with different types of risk behavior in Indonesian female prisoners, which can be relevant for future studies on infection prevention strategies for such a population.
Recent evidence suggests that certain vaccines, including Bacillus-Calmette Guérin (BCG), can induce changes in the innate immune system with non-specific memory characteristics, termed 'trained ...immunity'. Here we present the results of a randomised, controlled phase 1 clinical trial in 20 healthy male and female volunteers to evaluate the induction of immunity and protective efficacy of the anti-tuberculosis BCG vaccine against a controlled human malaria infection. After malaria challenge infection, BCG vaccinated volunteers present with earlier and more severe clinical adverse events, and have significantly earlier expression of NK cell activation markers and a trend towards earlier phenotypic monocyte activation. Furthermore, parasitemia in BCG vaccinated volunteers is inversely correlated with increased phenotypic NK cell and monocyte activation. The combined data demonstrate that BCG vaccination alters the clinical and immunological response to malaria, and form an impetus to further explore its potential in strategies for clinical malaria vaccine development.
Summary Background We have shown that immunity to infection with Plasmodium falciparum can be induced experimentally in malaria-naive volunteers through immunisation by bites of infected mosquitoes ...while simultaneously preventing disease with chloroquine prophylaxis. This immunity was associated with parasite-specific production of interferon γ and interleukin 2 by pluripotent effector memory cells in vitro. We aim to explore the persistence of protection and immune responses in the same volunteers. Methods In an open-label study at the Radboud University Nijmegen Medical Centre (Nijmegen, Netherlands), from November to December, 2009, we rechallenged previously immune volunteers (28 months after immunisation) with the bites of five mosquitoes infected with P falciparum . Newly recruited malaria-naive volunteers served as infection controls. Our primary outcome was the detection of blood-stage parasitaemia by microscopy. We assessed the kinetics of parasitaemia with real-time quantitative PCR (rtPCR) and recorded clinical signs and symptoms. In-vitro production of interferon γ and interleukin 2 by effector memory T cells was studied after stimulation with sporozoites and red blood cells infected with P falciparum . Differences in cellular immune responses between the study groups were assessed with the Mann-Whitney test. This study is registered with ClinicalTrials.gov , number NCT00757887. Findings Four of six immune volunteers were microscopically negative after rechallenge. rtPCR-based detection of blood-stage parasites in these individuals was negative throughout follow-up. Patent parasitaemia was delayed in the remaining two immunised volunteers. In-vitro assays showed the long-term persistence of parasite-specific pluripotent effector memory T-cell responses in protected volunteers. The four protected volunteers reported several mild to moderate adverse events, of which the most commonly reported symptom was headache (one to three episodes per volunteer). The two patients with delayed patency had adverse events similar to those in the control group. Interpretation Artificially induced immunity lasts longer than generally recorded after natural exposure; providing a new avenue of research into the mechanisms of malaria immunity. Funding Dioraphte Foundation.
ABSTRACT
Background
Vitamin D deficiency is frequently found in patients with chronic obstructive pulmonary disease (COPD). Vitamin D has antimicrobial, anti-inflammatory, and immunomodulatory ...effects. Therefore, supplementation may prevent COPD exacerbations, particularly in deficient patients.
Objectives
We aimed to assess the effect of vitamin D supplementation on exacerbation rate in vitamin D–deficient patients with COPD.
Methods
We performed a multicenter, double-blind, randomized controlled trial. COPD patients with ≥1 exacerbations in the preceding year and a vitamin D deficiency (15–50 nmol/L) were randomly allocated in a 1:1 ratio to receive either 16,800 International Units (IU) vitamin D3 or placebo once a week during 1 y. Primary outcome of the study was exacerbation rate. Secondary outcomes included time to first and second exacerbations, time to first and second hospitalizations, use of antibiotics and corticosteroids, pulmonary function, maximal respiratory mouth pressure, physical performance, skeletal muscle strength, systemic inflammatory markers, nasal microbiota composition, and quality of life.
Results
The intention-to-treat population consisted of 155 participants. Mean ± SD serum 25-hydroxyvitamin D 25(OH)D concentration after 1 y was 112 ± 34 nmol/L in the vitamin D group, compared with 42 ± 17 nmol/L in the placebo group. Vitamin D supplementation did not affect exacerbation rate incidence rate ratio (IRR): 0.90; 95% CI: 0.67, 1.21. In a prespecified subgroup analysis in participants with 25(OH)D concentrations of 15–25 nmol/L (n = 31), no effect of vitamin D supplementation was found (IRR: 0.91; 95% CI: 0.43, 1.93). No relevant differences were found between the intervention and placebo groups in terms of secondary outcomes.
Conclusions
Vitamin D supplementation did not reduce exacerbation rate in COPD patients with a vitamin D deficiency.
This trial was registered at clinicaltrials.gov as NCT02122627.
Abstract
CCR5 is the main HIV co-receptor. We aimed to (1) compare CCR5 expression on immune cells between people living with HIV (PLHIV) using combination antiretroviral therapy (cART) and ...HIV-uninfected controls, (2) relate CCR5 expression to viral reservoir size and (3) assess determinants of CCR5 expression. This cross-sectional study included 209 PLHIV and 323 controls. Percentages of CCR5+ cells (%) and CCR5 mean fluorescence intensity assessed by flow cytometry in monocytes and lymphocyte subsets were correlated to host factors, HIV-1 cell-associated (CA)-RNA and CA-DNA, plasma inflammation markers and metabolites. Metabolic pathways were identified. PLHIV displayed higher percentages of CCR5+ monocytes and several CD8+ T cell subsets, but lower percentages of CCR5+ naive CD4+ T cells and regulatory T cells (Tregs). HIV-1 CA-DNA and CA-RNA correlated positively with percentages of CCR5+ lymphocytes. Metabolome analysis revealed three pathways involved in energy metabolism associated with percentage of CCR5+ CD8+ T cells in PLHIV. Our results indicate that CCR5 is differently expressed on various circulating immune cells in PLHIV. Hence, cell-trafficking of CD8+ T cells and Tregs may be altered in PLHIV. Associations between energy pathways and percentage of CCR5+ CD8+ T cells in PLHIV suggest higher energy demand of these cells in PLHIV.
Volunteers immunized under chloroquine chemoprophylaxis with Plasmodium falciparum sporozoites (CPS) develop complete, long-lasting protection against homologous sporozoite challenge. Chloroquine ...affects neither sporozoites nor liver-stages, but kills only asexual forms in erythrocytes once released from the liver into the circulation. Consequently, CPS immunization exposes the host to antigens from both preerythrocytic and blood stages, and induced immunity might target either of these stages. We therefore explored the life cycle stage specificity of CPS-induced protection. Twenty-five malaria-naïve volunteers were enrolled in a clinical trial, 15 of whom received CPS immunization. Five immunized subjects and five controls received a sporozoite challenge by mosquito bites, whereas nine immunized and five control subjects received an i.v. challenge with P. falciparum- infected erythrocytes. The latter approach completely bypasses preerythrocytic stages, enabling a direct comparison of protection against either life cycle stage. CPS-immunized subjects (13 of 14) developed anticircumsporozoite antibodies, whereas only one volunteer generated minimal titers against typical blood-stage antigens. IgG from CPS-immunized volunteers did not inhibit asexual blood-stage growth in vitro. All CPS-immunized subjects (5 of 5) were protected against sporozoite challenge. In contrast, nine of nine CPS-immunized subjects developed parasitemia after blood-stage challenge, with identical prepatent periods and blood-stage multiplication rates compared with controls. Intravenously challenged CPS-immunized subjects showed earlier fever and increased plasma concentrations of inflammatory markers D-dimer, IFN-γ, and monokine induced by IFN-γ than i.v. challenged controls. The complete lack of protection against blood-stage challenge indicates that CPS-induced protection is mediated by immunity against preerythrocytic stages. However, evidence is presented for immune recognition of P. falciparum -infected erythrocytes, suggesting memory responses unable to generate functional immunity.
Exposing healthy human volunteers to Plasmodium falciparum-infected mosquitoes is an accepted tool to evaluate preliminary efficacy of malaria vaccines. To accommodate the demand of the malaria ...vaccine pipeline, controlled infections are carried out in an increasing number of centers worldwide. We assessed their safety and reproducibility.
We reviewed safety and parasitological data from 128 malaria-naïve subjects participating in controlled malaria infection trials conducted at the University of Oxford, UK, and the Radboud University Nijmegen Medical Center, The Netherlands. Results were compared to a report from the US Military Malaria Vaccine Program.
We show that controlled human malaria infection trials are safe and demonstrate a consistent safety profile with minor differences in the frequencies of arthralgia, fatigue, chills and fever between institutions. But prepatent periods show significant variation. Detailed analysis of Q-PCR data reveals highly synchronous blood stage parasite growth and multiplication rates.
Procedural differences can lead to some variation in safety profile and parasite kinetics between institutions. Further harmonization and standardization of protocols will be useful for wider adoption of these cost-effective small-scale efficacy trials. Nevertheless, parasite growth rates are highly reproducible, illustrating the robustness of controlled infections as a valid tool for malaria vaccine development.
The immunopathogenesis of dengue virus (DENV) infection remains incompletely understood. To increase our understanding of inflammatory response in non-severe dengue, we assessed longitudinal changes ...in the inflammatory proteome in patients with an acute DENV infection.
Using a multiplex proximity extension assay (PEA), we measured relative levels of 368 inflammatory markers in plasma samples from hospitalized patients with non-severe DENV infection in the acute (n = 43) and convalescence (n = 35) phase of the infection and samples of healthy controls (n = 10).
We identified 203 upregulated and 39 downregulated proteins in acute versus convalescent plasma samples. The upregulated proteins had a strong representation of interferon (IFN) and IFN-inducible effector proteins, cytokines (e.g. IL-10, IL-33) and cytokine receptors, chemokines, pro-apoptotic proteins (e.g. granzymes) and endothelial markers. A number of differentially expressed proteins (DEPs) have not been reported in previous studies. Functional network analysis highlighted a central role for IFNγ, IL-10, IL-33 and chemokines. We identified different novel associations between inflammatory proteins and circulating concentrations of the endothelial glycocalyx disruption surrogate marker syndecan-1. Conclusion: This unbiased proteome analysis provides a comprehensive insight in the inflammatory response in DENV infection and its association with glycocalyx disruption.
Objectives To review the current knowledge about tuberculosis (TB) and diabetes, assessing the implication of the global increase of diabetes for TB control and patient care. Methods Systematic ...literature review. Results Using public databases, it can be estimated that 12.6% (95% CI 9.2-17.3%) of new TB cases in the 10 countries with the highest TB burden will be attributable to TB in 2030, a relative increase of 25.5% compared to 2010. Diabetes is associated with a higher age and body weight among patients with TB, but probably not with a specific clinical presentation of TB. Rifampicin hampers glycemic control by increasing the metabolism of most oral antidiabetic drugs, while diabetes patients may have lower concentrations of anti‐TB drugs. This might be one factor contributing to higher TB treatment failure rates. Conclusions The global epidemic of diabetes has implications for control and treatment of TB. Prospective studies are needed to improve prevention, early detection and treatment of concomitant diabetes and TB, especially in developing countries.
Cellular responses to Plasmodium falciparum parasites, in particular interferon-gamma (IFNγ) production, play an important role in anti-malarial immunity. However, clinical immunity to malaria ...develops slowly amongst naturally exposed populations, the dynamics of cellular responses in relation to exposure are difficult to study and data about the persistence of such responses are controversial. Here we assess the longevity and composition of cellular immune responses following experimental malaria infection in human volunteers. We conducted a longitudinal study of cellular immunological responses to sporozoites (PfSpz) and asexual blood-stage (PfRBC) malaria parasites in naïve human volunteers undergoing single (n = 5) or multiple (n = 10) experimental P. falciparum infections under highly controlled conditions. IFNγ and interleukin-2 (IL-2) responses following in vitro re-stimulation were measured by flow-cytometry prior to, during and more than one year post infection. We show that cellular responses to both PfSpz and PfRBC are induced and remain almost undiminished up to 14 months after even a single malaria episode. Remarkably, not only 'adaptive' but also 'innate' lymphocyte subsets contribute to the increased IFNγ response, including αβT cells, γδT cells and NK cells. Furthermore, results from depletion and autologous recombination experiments of lymphocyte subsets suggest that immunological memory for PfRBC is carried within both the αβT cells and γδT compartments. Indeed, the majority of cytokine producing T lymphocytes express an CD45RO(+) CD62L(-) effector memory (EM) phenotype both early and late post infection. Finally, we demonstrate that malaria infection induces and maintains polyfunctional (IFNγ(+)IL-2(+)) EM responses against both PfRBC and PfSpz, previously found to be associated with protection. These data demonstrate that cellular responses can be readily induced and are long-lived following infection with P. falciparum, with a persisting contribution by not only adaptive but also (semi-)innate lymphocyte subsets. The implications hereof are positive for malaria vaccine development, but focus attention on those factors potentially inhibiting such responses in the field.
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