An observational study in Dengue (Virus); Fever, Sandfly and Sickle Cell Disease, sponsored by Centre Hospitalier Universitaire de la Guadeloupe. Recruiting at 1 site in Guadeloupe. Open to participants aged 6 Years to 25 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-06-03.
Sponsored by Centre Hospitalier Universitaire de la Guadeloupe · Observational
Dengue virus (DENV) belongs to the genus of Flavivirus transmitted by the mosquito Aedes aegypti and is responsible for an infectious disease associated with different forms and severities such as dengue hemorrhagic fever or shock syndrome. Several recent reports have shown that sickle cell patients exhibited an increased risk of developing severe forms of dengue episodes compared to non-sickle cell subjects. Furthermore, among major sickle cell syndromes, these studies suggest that SC patients are at the highest risk of death during these infectious episodes although this sickle cell syndrome is generally associated with a more moderate expression of sickle cell disease. However, the mechanisms involved remain unknown to date.
The aim of the present study is to identify the molecular and cellular basis of this increased severity of dengue in SC patients. We hypothesize an exacerbation during DENV infection of the inflammatory response in SC patients compared to SS patients.
More precisely, the objective is to determine and compare the different cellular and molecular inflammatory mediators between SS and SC patients at baseline, and to study DENV-induced activation of various blood figurative elements isolated from uninfected sickle cell patients in vitro.
Given the essential role of immune cells in the DENV cycle and in the innate and adaptive immune responses of the host, understanding the changes induced by viral infection in Peripheral Blood Mononuclear Cells (PBMC) and Monocyte-Derived Dendritic Cells (MDDC) remains a priority. The effect of DENV or DENV-Associated Molecular Patterns (PAMPs) will therefore be studied in vitro on purified cells from SC and SS patients.
The impact of MicroParticles (MPs), known to be involved in the pathogenesis of severe dengue forms and in sickle cell disease, will also be evaluated on two cell types: endothelial cells and neutrophils, the latter exhibiting exacerbated activation and production of Neutrophil Extracellular Traps (NETs).
Considering the influence of mosquito saliva components on the pathogenesis of arboviruses (including DENV) in vertebrate hosts through the amplification of inflammatory responses, a comparative analysis of cellular and molecular inflammatory mediators released following exposure of blood cells from SS and SC patients to DENV and Aedes aegypti saliva will be conducted in vitro.
Lastly, the differential blood profiles of SS and SC patients will be assessed for their impact on the vector competence of Aedes aegypti mosquitoes in transmitting DENV.
283 studies on the registry are indexed under Dengue; 44 are open to participants now.
This study's planned enrollment of 130 is below the median of 595 across 80 observational studies indexed under Dengue.
Browse Dengue studies →Centre Hospitalier Universitaire de la Guadeloupe is the lead sponsor of 50 studies on the registry; 25 are open to participants now.
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patients from 6 to 25 years, with sicke cell disease in a steady state at inclusion
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Fifty SS patients
Fifty SC patients
Patients without hemoglobin disease
Lymphocyte subpopulations measured by flow cytometry at steady-state
Comparison of circulating lymphocyte subpopulations in terms of activation and expression of markers of inflammation (cytokines, microparticles) and neutrophil proteome of SS and SC sickle cell patients at steady-state.
Time frame: baseline
activation status of immune cells induced by DENV
Quantification and comparison of activation state of immune cells (PBMC/monocytes) isolated from SS and SC sickle cell patients induced in vitro by DENV and/or DENV PAMPS (such as NS1 viral protein) in the presence or absence of mosquito saliva
Time frame: baseline
Comparative Analysis of NET Formation Induced by Sickle Cell-Derived Microparticles With or Without Mosquito Saliva
Comparison of the induction properties of Neutrophil Extracellular Traps (NETs) in vitro by microparticles isolated from SS and SC patients in the presence or absence of mosquito saliva
Time frame: baseline
Impact of SS and SC Blood Profiles on Aedes aegypti Biting Behavior and Dengue Virus Transmission
Evaluation of the influence of SS and SC blood profiles on the biting behavior of Aedes aegypti and its ability to transmit DENV.
Time frame: baseline
Plan to share: No
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Centre Hospitalier Universitaire de la Guadeloupe