20 research outputs found

    Time since Onset of Disease and Individual Clinical Markers Associate with Transcriptional Changes in Uncomplicated Dengue

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    Dengue virus (DENV) infection causes viral haemorrhagic fever that is characterized by extensive activation of the immune system. The aim of this study is to investigate the kinetics of the transcriptome signature changes during the course of disease and the association of genes in these signatures with clinical parameters. Sequential whole blood samples from DENV infected patients in Jakarta were profiled using affymetrix microarrays, which were analysed using principal component analysis, limma, gene set analysis, and weighted gene co-expression network analysis. We show that time since onset of disease, but not diagnosis, has a large impact on the blood transcriptome of patients with non-severe dengue. Clinical diagnosis (according to the WHO classification) does not associate with differential gene expression. Network analysis however, indicated that the clinical markers platelet count, fibrinogen, albumin, IV fluid distributed per day and liver enzymes SGOT and SGPT strongly correlate with gene modules that are enriched for genes involved in the immune response. Overall, we see a shift in the transcriptome from immunity and inflammation to repair and recovery during the course of a DENV infection. Time since onset of disease associates with the shift in transcriptome signatures from immunity and inflammation to cell cycle and repair mechanisms in patients with non-severe dengue. The strong association of time with blood transcriptome changes hampers both the discovery as well as the potential application of biomarkers in dengue. However, we identified gene expression modules that associate with key clinica

    Fine-mapping of prostate cancer susceptibility loci in a large meta-analysis identifies candidate causal variants

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    Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Peer reviewe

    Hyperferritinaemia in dengue virus infected patients is associated with immune activation and coagulation disturbances

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    Contains fulltext : 138893.pdf (publisher's version ) (Open Access)BACKGROUND: During a dengue outbreak on the Caribbean island Aruba, highly elevated levels of ferritin were detected in dengue virus infected patients. Ferritin is an acute-phase reactant and hyperferritinaemia is a hallmark of diseases caused by extensive immune activation, such as haemophagocytic lymphohistiocytosis. The aim of this study was to investigate whether hyperferritinaemia in dengue patients was associated with clinical markers of extensive immune activation and coagulation disturbances. METHODOLOGY/PRINCIPAL FINDINGS: Levels of ferritin, standard laboratory markers, sIL-2R, IL-18 and coagulation and fibrinolytic markers were determined in samples from patients with uncomplicated dengue in Aruba. Levels of ferritin were significantly increased in dengue patients compared to patients with other febrile illnesses. Moreover, levels of ferritin associated significantly with the occurrence of viraemia. Hyperferritinaemia was also significantly associated with thrombocytopenia, elevated liver enzymes and coagulation disturbances. The results were validated in a cohort of dengue virus infected patients in Brazil. In this cohort levels of ferritin and cytokine profiles were determined. Increased levels of ferritin in dengue virus infected patients in Brazil were associated with disease severity and a pro-inflammatory cytokine profile. CONCLUSIONS/SIGNIFICANCE: Altogether, we provide evidence that ferritin can be used as a clinical marker to discriminate between dengue and other febrile illnesses. The occurrence of hyperferritinaemia in dengue virus infected patients is indicative for highly active disease resulting in immune activation and coagulation disturbances. Therefore, we recommend that patients with hyperferritinaemia are monitored carefully

    Chikungunya virus-like particles are more immunogenic in a lethal AG129 mouse model compared to glycoprotein El or E2 subunits

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    Chikungunya virus (CHIKV) causes acute illness characterized by fever and long-lasting arthritic symptoms. The need for a safe and effective vaccine against CHM/infections is on the rise due to on-going vector spread and increasing severity of clinical complications. Here we report the results of a comparative vaccination-challenge experiment in mice using three different vaccine candidates produced in insect cells by recombinant baculoviruses: (i) secreted (s)E1 and (ii) sE2 CHIKV glycoprotein subunits (2 mu g/immunization), and (iii) CHIKV virus-like particles (VLPs) (1 mu g E2 equivalent/immunization). These experiments show that vaccination with two subsequent administrations of 1 mu g of Matrix M adjuvanted CHIN VLPs completely protected AG129 mice from lethal CHIN challenge. Vaccination with El and E2 subunits provided partial protection, with half of the mice surviving but with significantly lower neutralizing antibody titres as compared to the VLP vaccinated mice. This study provides evidence that even a modest neutralizing antibody response is sufficient to protect mice from CHM/infections. Neutralization was the prominent correlate of protection. In addition, CHIKV VLPs provide a superior immune response and protection against CHIICV-induced disease in mice as compared to individual CHIKV-sEl and -sE2 subunits. (C) 2013 Elsevier Ltd. All rights reserved

    Human to human transmission of arthropod-borne pathogens

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    Human-to-human (H2H) transmitted arthropod-borne pathogens are a growing burden worldwide, with malaria and dengue being the most common mosquito-borne H2H transmitted diseases. The ability of vectors to get infected by humans during a blood meal to further propel an epidemic depends on complex interactions between pathogens, vectors and humans, in which human interventions and demographic and environmental conditions play a significant role. Herein, we discuss the distal and proximal drivers affecting H2H vectorborne pathogen transmission and identify knowledge gaps and future perspectives

    Conditional deletion of TGF-βR1 using Langerin-Cre mice results in Langerhans cell deficiency and reduced contact hypersensitivity

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    The critical role of Langerhans cells (LC) in contact hypersensitivity (CHS) was recently questioned in studies using different LC-depletion mouse models. On one hand, inducible ablation of LC led to diminished ear swelling, suggesting functional redundancy between LC and (Langerin +) dermal dendritic cells (DC). On the other hand, constitutive or acute depletion of LC resulted in an enhanced reaction, supporting a regulatory role of LC in CHS. To address this controversy by conditional gene targeting, we generated Langerin-Cre knockin mice. Breeding these mice to a Cre-reporter strain demonstrated robust and specific DNA recombination in LC, as well as other Langerin + tissue DC. In agreement with the vital requirement of TGF-β signaling for LC development, crossing Langerin-Cre to mice homozygous for a loxP-flanked TGF-βR1 allele resulted in permanent LC deficiency, whereas the homeostasis of dermal Langerin + DC was unaffected. In the absence of LC, induction of CHS in these Langerin + DC-specific TGF-βR1-deficient mice elicited decreased ear swelling compared with controls. This novel approach provided further evidence against a regulatory function of LC in CHS. Moreover, these Langerin-Cre mice represent a unique and powerful tool to dissect the role and molecular control of Langerin + DC populations beyond LC. Copyrigh

    Noninvasive continuous arterial blood pressure monitoring with Nexfin (R)

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    Background: If invasive measurement of arterial blood pressure is not warranted, finger cuff technology can provide continuous and noninvasive monitoring. Finger and radial artery pressures differ; Nexfin (R) (BMEYE, Amsterdam, The Netherlands) measures finger arterial pressure and uses physiologic reconstruction methodologies to obtain values comparable to invasive pressures. Methods: Intra-arterial pressure (IAP) and noninvasive Nexfin arterial pressure (NAP) were measured in cardiothoracic surgery patients, because invasive pressures are available. NAP-IAP differences were analyzed during 30 min. Tracking was quantified by within-subject precision (SD of individual NAP-IAP differences) and correlation coefficients. The ranges of pressure change were quantified by within-subject variability (SD of individual averages of NAP and IAP). Accuracy and precision were expressed as group average +/- SD of the differences and considered acceptable when smaller than 5 +/- 8 mmHg, the Association for the Advancement of Medical Instrumentation criteria. Results: NAP and IAP were obtained in 50 (34-83 yr, 40 men) patients. For systolic, diastolic, mean arterial, and pulse pressure, median (25-75 percentiles) correlation coefficients were 0.96 (0.91-0.98), 0.93 (0.87-0.96), 0.96 (0.90-0.97), and 0.94 (0.85-0.98), respectively. Within-subject precisions were 4 +/- 2, 3 +/- 1, 3 +/- 2, and 3 +/- 2 mmHg, and within-subject variations 13 +/- 6, 6 +/- 3, 9 +/- 4, and 7 +/- 4 mmHg, indicating precision over a wide range of pressures. Group average +/- SD of the NAP-IAP differences were -1 +/- 7, 3 +/- 6, 2 +/- 6, and -3 +/- 4 mmHg, meeting criteria. Differences were not related to mean arterial pressure or heart rate. Conclusion: Arterial blood pressure can be measured non-invasively and continuously using physiologic pressure reconstruction. Changes in pressure can be followed and values are comparable to invasive monitorin

    Noninvasive continuous arterial blood pressure monitoring with Nexfin (R)

    No full text
    Background: If invasive measurement of arterial blood pressure is not warranted, finger cuff technology can provide continuous and noninvasive monitoring. Finger and radial artery pressures differ; Nexfin (R) (BMEYE, Amsterdam, The Netherlands) measures finger arterial pressure and uses physiologic reconstruction methodologies to obtain values comparable to invasive pressures. Methods: Intra-arterial pressure (IAP) and noninvasive Nexfin arterial pressure (NAP) were measured in cardiothoracic surgery patients, because invasive pressures are available. NAP-IAP differences were analyzed during 30 min. Tracking was quantified by within-subject precision (SD of individual NAP-IAP differences) and correlation coefficients. The ranges of pressure change were quantified by within-subject variability (SD of individual averages of NAP and IAP). Accuracy and precision were expressed as group average +/- SD of the differences and considered acceptable when smaller than 5 +/- 8 mmHg, the Association for the Advancement of Medical Instrumentation criteria. Results: NAP and IAP were obtained in 50 (34-83 yr, 40 men) patients. For systolic, diastolic, mean arterial, and pulse pressure, median (25-75 percentiles) correlation coefficients were 0.96 (0.91-0.98), 0.93 (0.87-0.96), 0.96 (0.90-0.97), and 0.94 (0.85-0.98), respectively. Within-subject precisions were 4 +/- 2, 3 +/- 1, 3 +/- 2, and 3 +/- 2 mmHg, and within-subject variations 13 +/- 6, 6 +/- 3, 9 +/- 4, and 7 +/- 4 mmHg, indicating precision over a wide range of pressures. Group average +/- SD of the NAP-IAP differences were -1 +/- 7, 3 +/- 6, 2 +/- 6, and -3 +/- 4 mmHg, meeting criteria. Differences were not related to mean arterial pressure or heart rate. Conclusion: Arterial blood pressure can be measured non-invasively and continuously using physiologic pressure reconstruction. Changes in pressure can be followed and values are comparable to invasive monitorin
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