Sabine Allard - Academia.edu (original) (raw)

Papers by Sabine Allard

Research paper thumbnail of Immuno-Diagnosis of Active Tuberculosis by a Combination of Cytokines/Chemokines Induced by Two Stage-Specific Mycobacterial Antigens: A Pilot Study in a Low TB Incidence Country

Frontiers in Immunology, 2022

Active tuberculosis (aTB) remains a major killer from infectious disease, partially due to delaye... more Active tuberculosis (aTB) remains a major killer from infectious disease, partially due to delayed diagnosis and hence treatment. Classical microbiological methods are slow and lack sensitivity, molecular techniques are costly and often unavailable. Moreover, available immuno-diagnostic tests lack sensitivity and do not differentiate between aTB and latent TB infection (LTBI). Here, we evaluated the performance of the combined measurement of different chemokines/cytokines induced by two different stage-specific mycobacterial antigens, Early-secreted-antigenic target-6 (ESAT-6) and Heparin-binding-haemagglutinin (HBHA), after a short in vitro incubation of either peripheral blood mononuclear cells (PBMC) or whole blood (WB). Blood samples were collected from a training cohort comprising 22 aTB patients, 22 LTBI subjects and 17 non-infected controls. The concentrations of 13 cytokines were measured in the supernatants. Random forest analysis identified the best markers to differentiat...

Research paper thumbnail of Healthcare-associated COVID-19 across 3 pandemic waves: patient characterisation and validation of clinical definitions using genome sequencing

BackgroundWorldwide, healthcare-associated SARS-CoV-2 infections are a major problem: they are as... more BackgroundWorldwide, healthcare-associated SARS-CoV-2 infections are a major problem: they are associated with increased morbidity, mortality, and hospitalization costs. In-depth studies across the pandemic are crucial to understand and prevent transmission in hospital settings. The principal aims of this study were to characterise patients and validate ECDC definitions of healthcare-associated COVID-19 infections.MethodsWe set up a retrospective observational study spanning the first three waves of the COVID-19 pandemic in a Belgian university hospital: it describes the characteristics of COVID-19 patients admitted, with either healthcare- or community-associated infections. We performed a cluster analysis through epidemiological and viral genome analyses of the healthcare-associated infections, in order to validate the ECDC definitions of healthcare-associated COVID-19 infections.ResultsBetween week 10 of 2020 and week 22 of 2021, 168 patients were hospitalized with healthcare-ass...

Research paper thumbnail of Variable overlap in HIV-1 env sequences from plasma virus after analytical treatment interruption and viral outgrowth assay

Research paper thumbnail of Invasive Group A Streptococcal infection in immunocompetent adults: step on the GAS!

Acta Clinica Belgica, 2015

Research paper thumbnail of A dendritic cell-based therapeutic vaccine against HIV-1

Research paper thumbnail of HIV-1 sequence evolution after dendritic cell-based immune therapy

Introduction: Abelmoschus Manihot (L.) Medik are herbal medicinal plants, which a rich source com... more Introduction: Abelmoschus Manihot (L.) Medik are herbal medicinal plants, which a rich source compounds of bioactive phytochemical nutrients both on the leaves and stems. Objective: The purpose of the study is analyze the total flavonoid, alkaloid and tannin equivalent on leaves and stems of Abelmoschus Manihot (L.) Medik extracts From Palu of central Sulawesi, was performed on Leaf and stems Extract (Ethanol). Methods: The present study is Analyze of total flavonoid equivalent quercetin, Analyze of total tannin equivalent tannic acid and Analyze of total Alkaloid equivalent quinine on leaves and stems of Abelmoschus Manihot (L.) Medik extracts was performed for Leaf and stems Extract (Ethanol). Results: The results potentially of total activity of flavonoid, alkaloid and tannin equivalent on leaves of Abelmoschus Manihot (L.) Medik is 2,39 %, 0,09 % and 63,60 % and the activity total of flavonoid, alkaloid and tannin equivalent on stems in Abelmoschus Manihot (L.) Medik is 0,46 %, 0,04 % and 12,45 %. Conclusion: The present study has Potential to further research with the extraction and isolated a chemichal compound of flavonoid, alkaloid and tannin from Abelmoschus Manihot (L.) Medik with proper standardization methods.

Research paper thumbnail of Optimization and immune monitoring of a dendritic cell based HIV vaccine

Research paper thumbnail of Antibiotic prescriptions in the context of suspected bacterial respiratory tract superinfections in the COVID-19 era: a retrospective quantitative analysis of antibiotic consumption and identification of antibiotic prescription drivers

Internal and Emergency Medicine, 2021

This study aims to quantify antibiotic consumption for suspected respiratory tract superinfection... more This study aims to quantify antibiotic consumption for suspected respiratory tract superinfections in COVID-19 patients, while investigating the associated drivers of antibiotic prescribing in light of the current signs of antibiotic overuse. Adult patients with a positive COVID-19 diagnosis admitted to a Belgian 721-bed university hospital were analyzed retrospectively (March 11th-May 4th, 2020), excluding short-term admissions (< 24 h). Antibiotic prescriptions were analyzed and quantified, using Defined Daily Doses (DDD) per admission and per 100 bed days. Possible drivers of antibiotic prescribing were identified by means of mixed effects logistic modelling analysis with backwards selection. Of all included admissions (n = 429), 39% (n = 171) were prescribed antibiotics for (presumed) respiratory tract superinfection (3.6 DDD/admission; 31.5 DDD/100 bed days). Consumption of beta-lactamase inhibitor-penicillin combinations was the highest (2.55 DDD/ admission; 23.3 DDD/100 bed days). Four drivers were identified: fever on admission (OR 2.97; 95% CI 1.42-6.22), lower SpO 2 /FiO 2 ratio on admission (OR 0.96; 95% CI 0.92-0.99), underlying pulmonary disease (OR 3.04; 95% CI 1.12-8.27) and longer hospital stay (OR 1.09; 95% CI 1.03-1.16). We present detailed quantitative antibiotic data for presumed respiratory tract superinfections in hospitalized COVID-19 patients. In addition to knowledge on antibiotic consumption, we hope antimicrobial stewardship programs will be able to use the drivers identified in this study to optimize their interventions in COVID-19 wards.

Research paper thumbnail of Early treatment with inhaled GM-CSF improves oxygenation and anti-viral immunity in COVID-19 induced lung injury – a randomized clinical trial

Granulocyte-macrophage colony-stimulating factor (GM-CSF) instructs monocytes to differentiate in... more Granulocyte-macrophage colony-stimulating factor (GM-CSF) instructs monocytes to differentiate into alveolar macrophages (AM) that preserve lung homeostasis. By comparing AM development in mouse and human, we discovered that COVID-19 patients showed marked defects in GM-CSF-dependent AM instruction. The multi-center, open-label, randomized, controlled SARPAC-trial evaluated the efficacy and safety of 5 days of inhalation of rhu-GM-CSF (sargramostim, Leukine®) in 81 non-ventilated patients with COVID-19 and hypoxemic respiratory failure identified by PaO2/FiO2 ratio < 350mmHg. At day 6, more patients in the sargramostim group experienced at least 25% improvement in oxygenation compared with the standard of care group. Higher numbers of circulating class-switched B cells and effector virus-specific CD8 lymphocytes were found in the sargramostim group. Treatment adverse events, including signs of cytokine storm, were not different between active and control group. This proof-of-conc...

Research paper thumbnail of Clinical features of Legionnaires’ disease at three Belgian university hospitals, a retrospective study

Acta Clinica Belgica, 2021

Introduction: Legionnaires' disease (LD) is a recognised cause of community-acquired pneumonia. H... more Introduction: Legionnaires' disease (LD) is a recognised cause of community-acquired pneumonia. However, Legionella is an overlooked pathogen in hospital-acquired pneumonia. The European Surveillance System 2008-2017 found 23% of the Belgian LD reported cases being healthcare-related, with a higher death-rate than in community-acquired patients. This study aims to describe patients admitted for community-acquired LD or affected by hospitalacquired LD and investigate discriminants associated with lethality. Methods: Medical records were retrospectively reviewed at three Belgian University Hospitals, between 1 January 2016 up to 31 January 2019. Hospital-acquired LD was defined as symptom onset at 10 days or more after admission, according to the Centres for Disease Control and prevention. Community-acquired LD was defined as diagnosis at admission or within 10 days after admission. Results: Fifty patients were included in the study, among them 26% were diagnosed with hospital-acquired LD. The case-fatality rate was 22%, with eight of the eleven deceased patients (73%) being in the hospital-acquired LD group. Medical history of asthma or chronic obstructive pulmonary disease and higher sequential organ failure assessment (SOFA) score at diagnosis were more frequently observed in the hospital-acquired LD group. Furthermore, significantly lower SOFA score at diagnosis of LD and higher rates of treatment with levofloxacin or moxifloxacin were observed in survivors. Conclusion: In the current cohort, LD death-rate was mainly driven by hospital-acquired LD patients. Hospital-acquired LD might especially affect patients with chronic respiratory disease. Respiratory fluoroquinolones treatment and lower SOFA score at diagnosis may be associated with favourable outcomes.

Research paper thumbnail of Therapeutic Vaccine in Chronically HIV-1-Infected Patients: A Randomized, Double-Blind, Placebo-Controlled Phase IIa Trial with HTI-TriMix

Vaccines, 2019

Therapeutic vaccinations aim to re-educate human immunodeficiency virus (HIV)-1-specific immune r... more Therapeutic vaccinations aim to re-educate human immunodeficiency virus (HIV)-1-specific immune responses to achieve durable control of HIV-1 replication in virally suppressed infected individuals after antiretroviral therapy (ART) is interrupted. In a double blinded, placebo-controlled phase IIa multicenter study, we investigated the safety and immunogenicity of intranodal administration of the HIVACAT T cell Immunogen (HTI)-TriMix vaccine. It consists of naked mRNA based on cytotoxic T lymphocyte (CTL) targets of subdominant and conserved HIV-1 regions (HTI), in combination with mRNAs encoding constitutively active TLR4, the ligand for CD40 and CD70 as adjuvants (TriMix). We recruited HIV-1-infected individuals under stable ART. Study-arms HTI-TriMix, TriMix or Water for Injection were assigned in an 8:3:3 ratio. Participants received three vaccinations at weeks 0, 2, and 4 in an inguinal lymph node. Two weeks after the last vaccination, immunogenicity was evaluated using ELISpot ...

Research paper thumbnail of Correction to: iHIVARNA phase IIa, a randomized, placebo-controlled, double-blinded trial to evaluate the safety and immunogenicity of iHIVARNA-01 in chronically HIV-infected patients under stable combined antiretroviral therapy

Trials, 2019

Following publication of the original article [1], we have been notified that end note would need... more Following publication of the original article [1], we have been notified that end note would need to be adjusted.

Research paper thumbnail of iHIVARNA phase IIa, a randomized, placebo-controlled, double-blinded trial to evaluate the safety and immunogenicity of iHIVARNA-01 in chronically HIV-infected patients under stable combined antiretroviral therapy

Trials, 2019

Background: HIV therapeutic vaccination aims to improve the immune responses against HIV in order... more Background: HIV therapeutic vaccination aims to improve the immune responses against HIV in order to control viral replication without the need for combined antiretroviral therapy (cART). iHIVARNA-01 is a novel vaccine combining mRNA delivery and T-cell immunogen (HTI) based on conserved targets of effective antiviral T-cell responses. In addition, it holds adequate stimuli required for activating antigen presenting cells (APC)s and coactivating specific T-cells (TriMix), including human CD40L, constitutively active TLR4 (caTLR4) and CD70. We propose that in-vivo targeting of dendritic cells (DCs) by direct administration of a HIV mRNA encoding these immune modulating proteins might be an attractive alternative to target DCs in vitro.

Research paper thumbnail of High uptake of pre-exposure prophylaxis (PrEP) during early roll-out in Belgium: results from surveillance reports

Sexual Health, 2018

Background Since 1 June 2017, oral pre-exposure prophylaxis (PrEP) could be prescribed and reimbu... more Background Since 1 June 2017, oral pre-exposure prophylaxis (PrEP) could be prescribed and reimbursed in Belgium as prophylactic medication for people who are at increased risk of HIV acquisition. The aim of this study was to determine the uptake of daily and event-driven PrEP in Belgium during the first 9 months of roll-out. Methods: Routine aggregated data on the number of reimbursement requests and the number of boxes of Truvada (Gilead Sciences, Cambridge, UK) delivered for PrEP through the Belgian pharmacies were obtained from the National Institute for Health and Disability Insurance. We also collected aggregated data from seven Aids Reference Centres (ARCs) currently providing most of the PrEP care in Belgium. Results: From 1 June 2017 to 28 February 2018, 1352 requests for reimbursement were approved by the National Institute for Health and Disability Insurance. Almost 98% of those who bought at least one box of 30 tablets of emtricitabine 200mg/tenofovir disoproxil fumarate...

Research paper thumbnail of Blood tolerogenic monocytes and low proportions of dendritic cell subpopulations are hallmarks of human tuberculosis

Journal of leukocyte biology, Jan 28, 2018

The immune mechanisms underlying the pathogenesis of tuberculosis (TB) need better understanding ... more The immune mechanisms underlying the pathogenesis of tuberculosis (TB) need better understanding to improve TB management, as the disease still causes more than 1.5 million deaths annually. This study tested the hypothesis that a modulation of the proportions or activation status of APC during Mycobacterium tuberculosis infection may impact on the course of the disease. Proportions of circulating APC subsets and the expression of stimulatory (CD86), inhibitory (ILT-3, ILT-4, ILT-7), or apoptosis-inducing (PDL-1, PDL-2) molecules were analyzed in 2 independent cohorts, on blood monocytes and dendritic cell (DC) subsets from patients with active or latent TB infection (aTB /LTBI) and from uninfected subjects. Higher proportions of classical CD14 CD16 and intermediate CD14 CD16 monocytes, and lower proportions of plasmacytoid DC (pDC) and type 2 myeloid DC were observed in the blood from untreated patients with aTB compared with those with LTBI and with healthy subjects, with an early ...

Research paper thumbnail of Haemophagocytic Syndrome in a 19-Year-Old Male with Plasmodium falciparum Malaria

European Journal of Case Reports in Internal Medicine, 2014

Objectives: Infectious agents triggering haemophagocytic lymphohistiocytosis (HLH) primarily invo... more Objectives: Infectious agents triggering haemophagocytic lymphohistiocytosis (HLH) primarily involve the herpes virus group. We report a case of HLH precipitated by Plasmodium falciparum. Materials and methods: Clinical and laboratory findings in a patient presenting with fever were collected. After confirmation of acute malaria, anti-malarial treatment was administered. Results: Despite initial favourable evolution, the patient developed fever again together with a worsening of the haematological parameters and increased ferritin levels. A bone marrow biopsy confirmed the diagnosis of HLH. Conclusion: This case illustrates that HLH should be considered in the differential diagnosis of acute malaria in patients with persisting fever and pancytopenia.

Research paper thumbnail of Uncommon gastrointestinal manifestations of long-term cannabis use

Research paper thumbnail of DC immunotherapy in HIV-1 infection induces a major blood transcriptome shift

Vaccine, 2015

This study aimed to evaluate the effect of dendritic cell (DC) vaccination against HIV-1 on host ... more This study aimed to evaluate the effect of dendritic cell (DC) vaccination against HIV-1 on host gene expression profiles. Longitudinal PBMC samples were collected from participants of the DC-TRN trial for immunotherapy against HIV. Microarray-assisted gene expression profiling was performed to evaluate the effects of vaccination and subsequent interruption of antiretroviral therapy on host genome expression. Data from the DC-TRN trial were compared with results from other vaccination trials. We used Affymetrix GeneChips for microarray gene expression analysis. Data were analyzed by principal component analysis and differential gene expression was assessed using linear modeling. Gene ontology enrichment and gene set analysis were used to characterize differentially expressed genes. Transcriptome analysis included comparison with PBMCs obtained from DC-vaccinated melanoma patients and of healthy individuals who received seasonal influenza vaccination. DC-TRN immunotherapy in HIV-infected individuals resulted in a major shift in the transcriptome. Longitudinal analysis demonstrated that changes in the transcriptome sustained also during interruption of antiretroviral therapy. After DC-vaccination, the transcriptome was enriched for cellular immunity associated genes that were also induced in healthy adults who received live attenuated influenza virus vaccination. These beneficial responses were accompanied by detrimental signals of general immune activation. The DC-TRN induced changes in the transcriptome were profound, lasting, and consisted of both protective signals and signatures of inflammation and immune exhaustion, with a net result of decreased viral load, without clinical benefit. Thus transcriptome analysis provides useful information, dissecting both positive and negative effects, for the evaluation of safety and efficacy of immunotherapeutic strategies.

Research paper thumbnail of Lumenal Part of the DC-LAMP Protein Is Not Required for Induction of Antigen-Specific T Cell Responses by Means of Antigen-DC-LAMP Messenger RNA-Electroporated Dendritic Cells

Human Gene Therapy, 2010

Previous studies showed that stimulation of T cells derived from HIV-1-infected patients with aut... more Previous studies showed that stimulation of T cells derived from HIV-1-infected patients with autologous dendritic cells electroporated with mRNA encoding HIV antigens can induce antigen-specific T cell responses in vitro. Linking the antigen to an MHC class II-targeting sequence, such as dendritic cell lysosome-associated membrane protein (DC-LAMP), in the mRNA construct results in presentation of antigenic peptides in both MHC class I and class II molecules and therefore enhances the induced T cell responses. To analyze whether the lumenal domain of DC-LAMP is required for optimal induction of cellular immunity against HIV antigens, we compared fusion constructs with or without the lumenal domain of the DC-LAMP protein. A human codon-optimized consensus Gag sequence and a chimeric cDNA sequence encompassing Tat, Rev, and Nef codons (TaReNef ) were cloned into a vector containing the DC-LAMP sequence with or without its lumenal domain. The Gag protein lacking the DC-LAMP-derived sequence altogether elicited only weak T cell responses. DCs electroporated with Gag or TaReNef linked to DC-LAMP were able to elicit similar levels of antigen-specific CD4(+) and CD8(+) T cell responses for both Gag and TaReNef, irrespective of the addition of the DC-LAMP lumenal domain. These data show that DC-LAMP-mediated antigen targeting is absolutely required for optimal T cell stimulation, but that in our experimental setup, the lumenal part of DC-LAMP does not improve the overall induction of antigen-specific T cell responses.

Research paper thumbnail of Electroporation of immature and mature dendritic cells: implications for dendritic cell-based vaccines

Gene Therapy, 2005

Until now, studies utilizing mRNA electroporation as a tool for the delivery of tumor antigens to... more Until now, studies utilizing mRNA electroporation as a tool for the delivery of tumor antigens to human monocyte-derived dendritic cells (DC) have focused on DC electroporated in an immature state. Immature DC are considered to be specialized in antigen capture and processing, whereas mature DC present antigen and have an increased T-cell stimulatory capacity. Therefore, the consensus has been to electroporate DC before maturation. We show that the transfection efficiency of DC electroporated either before or after maturation was similarly high. Both immature and mature electroporated DC, matured in the presence of an inflammatory cytokine cocktail, expressed mature DC surface markers and preserved their capacity to secrete cytokines and chemokines upon CD40 ligation. In addition, both immature and mature DC can be efficiently cryopreserved before or after electroporation without deleterious effects on viability, phenotype or T-cell stimulatory capacity including in vitro antigen-specific T-cell activation. However, DC electroporated after maturation are more efficient in in vitro migration assays and at least as effective in antigen presentation as DC electroporated before maturation. These results are important for vaccination strategies where an optimal antigen presentation by DC after migration to the lymphoid organs is crucial.

Research paper thumbnail of Immuno-Diagnosis of Active Tuberculosis by a Combination of Cytokines/Chemokines Induced by Two Stage-Specific Mycobacterial Antigens: A Pilot Study in a Low TB Incidence Country

Frontiers in Immunology, 2022

Active tuberculosis (aTB) remains a major killer from infectious disease, partially due to delaye... more Active tuberculosis (aTB) remains a major killer from infectious disease, partially due to delayed diagnosis and hence treatment. Classical microbiological methods are slow and lack sensitivity, molecular techniques are costly and often unavailable. Moreover, available immuno-diagnostic tests lack sensitivity and do not differentiate between aTB and latent TB infection (LTBI). Here, we evaluated the performance of the combined measurement of different chemokines/cytokines induced by two different stage-specific mycobacterial antigens, Early-secreted-antigenic target-6 (ESAT-6) and Heparin-binding-haemagglutinin (HBHA), after a short in vitro incubation of either peripheral blood mononuclear cells (PBMC) or whole blood (WB). Blood samples were collected from a training cohort comprising 22 aTB patients, 22 LTBI subjects and 17 non-infected controls. The concentrations of 13 cytokines were measured in the supernatants. Random forest analysis identified the best markers to differentiat...

Research paper thumbnail of Healthcare-associated COVID-19 across 3 pandemic waves: patient characterisation and validation of clinical definitions using genome sequencing

BackgroundWorldwide, healthcare-associated SARS-CoV-2 infections are a major problem: they are as... more BackgroundWorldwide, healthcare-associated SARS-CoV-2 infections are a major problem: they are associated with increased morbidity, mortality, and hospitalization costs. In-depth studies across the pandemic are crucial to understand and prevent transmission in hospital settings. The principal aims of this study were to characterise patients and validate ECDC definitions of healthcare-associated COVID-19 infections.MethodsWe set up a retrospective observational study spanning the first three waves of the COVID-19 pandemic in a Belgian university hospital: it describes the characteristics of COVID-19 patients admitted, with either healthcare- or community-associated infections. We performed a cluster analysis through epidemiological and viral genome analyses of the healthcare-associated infections, in order to validate the ECDC definitions of healthcare-associated COVID-19 infections.ResultsBetween week 10 of 2020 and week 22 of 2021, 168 patients were hospitalized with healthcare-ass...

Research paper thumbnail of Variable overlap in HIV-1 env sequences from plasma virus after analytical treatment interruption and viral outgrowth assay

Research paper thumbnail of Invasive Group A Streptococcal infection in immunocompetent adults: step on the GAS!

Acta Clinica Belgica, 2015

Research paper thumbnail of A dendritic cell-based therapeutic vaccine against HIV-1

Research paper thumbnail of HIV-1 sequence evolution after dendritic cell-based immune therapy

Introduction: Abelmoschus Manihot (L.) Medik are herbal medicinal plants, which a rich source com... more Introduction: Abelmoschus Manihot (L.) Medik are herbal medicinal plants, which a rich source compounds of bioactive phytochemical nutrients both on the leaves and stems. Objective: The purpose of the study is analyze the total flavonoid, alkaloid and tannin equivalent on leaves and stems of Abelmoschus Manihot (L.) Medik extracts From Palu of central Sulawesi, was performed on Leaf and stems Extract (Ethanol). Methods: The present study is Analyze of total flavonoid equivalent quercetin, Analyze of total tannin equivalent tannic acid and Analyze of total Alkaloid equivalent quinine on leaves and stems of Abelmoschus Manihot (L.) Medik extracts was performed for Leaf and stems Extract (Ethanol). Results: The results potentially of total activity of flavonoid, alkaloid and tannin equivalent on leaves of Abelmoschus Manihot (L.) Medik is 2,39 %, 0,09 % and 63,60 % and the activity total of flavonoid, alkaloid and tannin equivalent on stems in Abelmoschus Manihot (L.) Medik is 0,46 %, 0,04 % and 12,45 %. Conclusion: The present study has Potential to further research with the extraction and isolated a chemichal compound of flavonoid, alkaloid and tannin from Abelmoschus Manihot (L.) Medik with proper standardization methods.

Research paper thumbnail of Optimization and immune monitoring of a dendritic cell based HIV vaccine

Research paper thumbnail of Antibiotic prescriptions in the context of suspected bacterial respiratory tract superinfections in the COVID-19 era: a retrospective quantitative analysis of antibiotic consumption and identification of antibiotic prescription drivers

Internal and Emergency Medicine, 2021

This study aims to quantify antibiotic consumption for suspected respiratory tract superinfection... more This study aims to quantify antibiotic consumption for suspected respiratory tract superinfections in COVID-19 patients, while investigating the associated drivers of antibiotic prescribing in light of the current signs of antibiotic overuse. Adult patients with a positive COVID-19 diagnosis admitted to a Belgian 721-bed university hospital were analyzed retrospectively (March 11th-May 4th, 2020), excluding short-term admissions (< 24 h). Antibiotic prescriptions were analyzed and quantified, using Defined Daily Doses (DDD) per admission and per 100 bed days. Possible drivers of antibiotic prescribing were identified by means of mixed effects logistic modelling analysis with backwards selection. Of all included admissions (n = 429), 39% (n = 171) were prescribed antibiotics for (presumed) respiratory tract superinfection (3.6 DDD/admission; 31.5 DDD/100 bed days). Consumption of beta-lactamase inhibitor-penicillin combinations was the highest (2.55 DDD/ admission; 23.3 DDD/100 bed days). Four drivers were identified: fever on admission (OR 2.97; 95% CI 1.42-6.22), lower SpO 2 /FiO 2 ratio on admission (OR 0.96; 95% CI 0.92-0.99), underlying pulmonary disease (OR 3.04; 95% CI 1.12-8.27) and longer hospital stay (OR 1.09; 95% CI 1.03-1.16). We present detailed quantitative antibiotic data for presumed respiratory tract superinfections in hospitalized COVID-19 patients. In addition to knowledge on antibiotic consumption, we hope antimicrobial stewardship programs will be able to use the drivers identified in this study to optimize their interventions in COVID-19 wards.

Research paper thumbnail of Early treatment with inhaled GM-CSF improves oxygenation and anti-viral immunity in COVID-19 induced lung injury – a randomized clinical trial

Granulocyte-macrophage colony-stimulating factor (GM-CSF) instructs monocytes to differentiate in... more Granulocyte-macrophage colony-stimulating factor (GM-CSF) instructs monocytes to differentiate into alveolar macrophages (AM) that preserve lung homeostasis. By comparing AM development in mouse and human, we discovered that COVID-19 patients showed marked defects in GM-CSF-dependent AM instruction. The multi-center, open-label, randomized, controlled SARPAC-trial evaluated the efficacy and safety of 5 days of inhalation of rhu-GM-CSF (sargramostim, Leukine®) in 81 non-ventilated patients with COVID-19 and hypoxemic respiratory failure identified by PaO2/FiO2 ratio < 350mmHg. At day 6, more patients in the sargramostim group experienced at least 25% improvement in oxygenation compared with the standard of care group. Higher numbers of circulating class-switched B cells and effector virus-specific CD8 lymphocytes were found in the sargramostim group. Treatment adverse events, including signs of cytokine storm, were not different between active and control group. This proof-of-conc...

Research paper thumbnail of Clinical features of Legionnaires’ disease at three Belgian university hospitals, a retrospective study

Acta Clinica Belgica, 2021

Introduction: Legionnaires' disease (LD) is a recognised cause of community-acquired pneumonia. H... more Introduction: Legionnaires' disease (LD) is a recognised cause of community-acquired pneumonia. However, Legionella is an overlooked pathogen in hospital-acquired pneumonia. The European Surveillance System 2008-2017 found 23% of the Belgian LD reported cases being healthcare-related, with a higher death-rate than in community-acquired patients. This study aims to describe patients admitted for community-acquired LD or affected by hospitalacquired LD and investigate discriminants associated with lethality. Methods: Medical records were retrospectively reviewed at three Belgian University Hospitals, between 1 January 2016 up to 31 January 2019. Hospital-acquired LD was defined as symptom onset at 10 days or more after admission, according to the Centres for Disease Control and prevention. Community-acquired LD was defined as diagnosis at admission or within 10 days after admission. Results: Fifty patients were included in the study, among them 26% were diagnosed with hospital-acquired LD. The case-fatality rate was 22%, with eight of the eleven deceased patients (73%) being in the hospital-acquired LD group. Medical history of asthma or chronic obstructive pulmonary disease and higher sequential organ failure assessment (SOFA) score at diagnosis were more frequently observed in the hospital-acquired LD group. Furthermore, significantly lower SOFA score at diagnosis of LD and higher rates of treatment with levofloxacin or moxifloxacin were observed in survivors. Conclusion: In the current cohort, LD death-rate was mainly driven by hospital-acquired LD patients. Hospital-acquired LD might especially affect patients with chronic respiratory disease. Respiratory fluoroquinolones treatment and lower SOFA score at diagnosis may be associated with favourable outcomes.

Research paper thumbnail of Therapeutic Vaccine in Chronically HIV-1-Infected Patients: A Randomized, Double-Blind, Placebo-Controlled Phase IIa Trial with HTI-TriMix

Vaccines, 2019

Therapeutic vaccinations aim to re-educate human immunodeficiency virus (HIV)-1-specific immune r... more Therapeutic vaccinations aim to re-educate human immunodeficiency virus (HIV)-1-specific immune responses to achieve durable control of HIV-1 replication in virally suppressed infected individuals after antiretroviral therapy (ART) is interrupted. In a double blinded, placebo-controlled phase IIa multicenter study, we investigated the safety and immunogenicity of intranodal administration of the HIVACAT T cell Immunogen (HTI)-TriMix vaccine. It consists of naked mRNA based on cytotoxic T lymphocyte (CTL) targets of subdominant and conserved HIV-1 regions (HTI), in combination with mRNAs encoding constitutively active TLR4, the ligand for CD40 and CD70 as adjuvants (TriMix). We recruited HIV-1-infected individuals under stable ART. Study-arms HTI-TriMix, TriMix or Water for Injection were assigned in an 8:3:3 ratio. Participants received three vaccinations at weeks 0, 2, and 4 in an inguinal lymph node. Two weeks after the last vaccination, immunogenicity was evaluated using ELISpot ...

Research paper thumbnail of Correction to: iHIVARNA phase IIa, a randomized, placebo-controlled, double-blinded trial to evaluate the safety and immunogenicity of iHIVARNA-01 in chronically HIV-infected patients under stable combined antiretroviral therapy

Trials, 2019

Following publication of the original article [1], we have been notified that end note would need... more Following publication of the original article [1], we have been notified that end note would need to be adjusted.

Research paper thumbnail of iHIVARNA phase IIa, a randomized, placebo-controlled, double-blinded trial to evaluate the safety and immunogenicity of iHIVARNA-01 in chronically HIV-infected patients under stable combined antiretroviral therapy

Trials, 2019

Background: HIV therapeutic vaccination aims to improve the immune responses against HIV in order... more Background: HIV therapeutic vaccination aims to improve the immune responses against HIV in order to control viral replication without the need for combined antiretroviral therapy (cART). iHIVARNA-01 is a novel vaccine combining mRNA delivery and T-cell immunogen (HTI) based on conserved targets of effective antiviral T-cell responses. In addition, it holds adequate stimuli required for activating antigen presenting cells (APC)s and coactivating specific T-cells (TriMix), including human CD40L, constitutively active TLR4 (caTLR4) and CD70. We propose that in-vivo targeting of dendritic cells (DCs) by direct administration of a HIV mRNA encoding these immune modulating proteins might be an attractive alternative to target DCs in vitro.

Research paper thumbnail of High uptake of pre-exposure prophylaxis (PrEP) during early roll-out in Belgium: results from surveillance reports

Sexual Health, 2018

Background Since 1 June 2017, oral pre-exposure prophylaxis (PrEP) could be prescribed and reimbu... more Background Since 1 June 2017, oral pre-exposure prophylaxis (PrEP) could be prescribed and reimbursed in Belgium as prophylactic medication for people who are at increased risk of HIV acquisition. The aim of this study was to determine the uptake of daily and event-driven PrEP in Belgium during the first 9 months of roll-out. Methods: Routine aggregated data on the number of reimbursement requests and the number of boxes of Truvada (Gilead Sciences, Cambridge, UK) delivered for PrEP through the Belgian pharmacies were obtained from the National Institute for Health and Disability Insurance. We also collected aggregated data from seven Aids Reference Centres (ARCs) currently providing most of the PrEP care in Belgium. Results: From 1 June 2017 to 28 February 2018, 1352 requests for reimbursement were approved by the National Institute for Health and Disability Insurance. Almost 98% of those who bought at least one box of 30 tablets of emtricitabine 200mg/tenofovir disoproxil fumarate...

Research paper thumbnail of Blood tolerogenic monocytes and low proportions of dendritic cell subpopulations are hallmarks of human tuberculosis

Journal of leukocyte biology, Jan 28, 2018

The immune mechanisms underlying the pathogenesis of tuberculosis (TB) need better understanding ... more The immune mechanisms underlying the pathogenesis of tuberculosis (TB) need better understanding to improve TB management, as the disease still causes more than 1.5 million deaths annually. This study tested the hypothesis that a modulation of the proportions or activation status of APC during Mycobacterium tuberculosis infection may impact on the course of the disease. Proportions of circulating APC subsets and the expression of stimulatory (CD86), inhibitory (ILT-3, ILT-4, ILT-7), or apoptosis-inducing (PDL-1, PDL-2) molecules were analyzed in 2 independent cohorts, on blood monocytes and dendritic cell (DC) subsets from patients with active or latent TB infection (aTB /LTBI) and from uninfected subjects. Higher proportions of classical CD14 CD16 and intermediate CD14 CD16 monocytes, and lower proportions of plasmacytoid DC (pDC) and type 2 myeloid DC were observed in the blood from untreated patients with aTB compared with those with LTBI and with healthy subjects, with an early ...

Research paper thumbnail of Haemophagocytic Syndrome in a 19-Year-Old Male with Plasmodium falciparum Malaria

European Journal of Case Reports in Internal Medicine, 2014

Objectives: Infectious agents triggering haemophagocytic lymphohistiocytosis (HLH) primarily invo... more Objectives: Infectious agents triggering haemophagocytic lymphohistiocytosis (HLH) primarily involve the herpes virus group. We report a case of HLH precipitated by Plasmodium falciparum. Materials and methods: Clinical and laboratory findings in a patient presenting with fever were collected. After confirmation of acute malaria, anti-malarial treatment was administered. Results: Despite initial favourable evolution, the patient developed fever again together with a worsening of the haematological parameters and increased ferritin levels. A bone marrow biopsy confirmed the diagnosis of HLH. Conclusion: This case illustrates that HLH should be considered in the differential diagnosis of acute malaria in patients with persisting fever and pancytopenia.

Research paper thumbnail of Uncommon gastrointestinal manifestations of long-term cannabis use

Research paper thumbnail of DC immunotherapy in HIV-1 infection induces a major blood transcriptome shift

Vaccine, 2015

This study aimed to evaluate the effect of dendritic cell (DC) vaccination against HIV-1 on host ... more This study aimed to evaluate the effect of dendritic cell (DC) vaccination against HIV-1 on host gene expression profiles. Longitudinal PBMC samples were collected from participants of the DC-TRN trial for immunotherapy against HIV. Microarray-assisted gene expression profiling was performed to evaluate the effects of vaccination and subsequent interruption of antiretroviral therapy on host genome expression. Data from the DC-TRN trial were compared with results from other vaccination trials. We used Affymetrix GeneChips for microarray gene expression analysis. Data were analyzed by principal component analysis and differential gene expression was assessed using linear modeling. Gene ontology enrichment and gene set analysis were used to characterize differentially expressed genes. Transcriptome analysis included comparison with PBMCs obtained from DC-vaccinated melanoma patients and of healthy individuals who received seasonal influenza vaccination. DC-TRN immunotherapy in HIV-infected individuals resulted in a major shift in the transcriptome. Longitudinal analysis demonstrated that changes in the transcriptome sustained also during interruption of antiretroviral therapy. After DC-vaccination, the transcriptome was enriched for cellular immunity associated genes that were also induced in healthy adults who received live attenuated influenza virus vaccination. These beneficial responses were accompanied by detrimental signals of general immune activation. The DC-TRN induced changes in the transcriptome were profound, lasting, and consisted of both protective signals and signatures of inflammation and immune exhaustion, with a net result of decreased viral load, without clinical benefit. Thus transcriptome analysis provides useful information, dissecting both positive and negative effects, for the evaluation of safety and efficacy of immunotherapeutic strategies.

Research paper thumbnail of Lumenal Part of the DC-LAMP Protein Is Not Required for Induction of Antigen-Specific T Cell Responses by Means of Antigen-DC-LAMP Messenger RNA-Electroporated Dendritic Cells

Human Gene Therapy, 2010

Previous studies showed that stimulation of T cells derived from HIV-1-infected patients with aut... more Previous studies showed that stimulation of T cells derived from HIV-1-infected patients with autologous dendritic cells electroporated with mRNA encoding HIV antigens can induce antigen-specific T cell responses in vitro. Linking the antigen to an MHC class II-targeting sequence, such as dendritic cell lysosome-associated membrane protein (DC-LAMP), in the mRNA construct results in presentation of antigenic peptides in both MHC class I and class II molecules and therefore enhances the induced T cell responses. To analyze whether the lumenal domain of DC-LAMP is required for optimal induction of cellular immunity against HIV antigens, we compared fusion constructs with or without the lumenal domain of the DC-LAMP protein. A human codon-optimized consensus Gag sequence and a chimeric cDNA sequence encompassing Tat, Rev, and Nef codons (TaReNef ) were cloned into a vector containing the DC-LAMP sequence with or without its lumenal domain. The Gag protein lacking the DC-LAMP-derived sequence altogether elicited only weak T cell responses. DCs electroporated with Gag or TaReNef linked to DC-LAMP were able to elicit similar levels of antigen-specific CD4(+) and CD8(+) T cell responses for both Gag and TaReNef, irrespective of the addition of the DC-LAMP lumenal domain. These data show that DC-LAMP-mediated antigen targeting is absolutely required for optimal T cell stimulation, but that in our experimental setup, the lumenal part of DC-LAMP does not improve the overall induction of antigen-specific T cell responses.

Research paper thumbnail of Electroporation of immature and mature dendritic cells: implications for dendritic cell-based vaccines

Gene Therapy, 2005

Until now, studies utilizing mRNA electroporation as a tool for the delivery of tumor antigens to... more Until now, studies utilizing mRNA electroporation as a tool for the delivery of tumor antigens to human monocyte-derived dendritic cells (DC) have focused on DC electroporated in an immature state. Immature DC are considered to be specialized in antigen capture and processing, whereas mature DC present antigen and have an increased T-cell stimulatory capacity. Therefore, the consensus has been to electroporate DC before maturation. We show that the transfection efficiency of DC electroporated either before or after maturation was similarly high. Both immature and mature electroporated DC, matured in the presence of an inflammatory cytokine cocktail, expressed mature DC surface markers and preserved their capacity to secrete cytokines and chemokines upon CD40 ligation. In addition, both immature and mature DC can be efficiently cryopreserved before or after electroporation without deleterious effects on viability, phenotype or T-cell stimulatory capacity including in vitro antigen-specific T-cell activation. However, DC electroporated after maturation are more efficient in in vitro migration assays and at least as effective in antigen presentation as DC electroporated before maturation. These results are important for vaccination strategies where an optimal antigen presentation by DC after migration to the lymphoid organs is crucial.