Dengue (Virus); Fever, SandflyDREPADENGUENCT07000747
Molecular and Cellular Basis of Severe Forms of Dengue in Sickle Cell Patients
An observational study of Dengue (Virus); Fever, Sandfly and Sickle Cell Disease, run by Centre Hospitalier Universitaire de la Guadeloupe at 1 site in Guadeloupe.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 6 to 25 yearsHealthy volunteers can take part
- Conditions the study is for
- Dengue (Virus); Fever, Sandfly, Sickle Cell Disease
- How many people
- 130 participants
- Where
- 1 siteGuadeloupe
- Study dates
- 24 Jun 2024to 24 Jun 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 25 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: patients from 6 to 25 years, with sicke cell disease in a steady state at inclusion
Who may be able to join
- patients with SS or SC SCD or controls with hemoglobin AA
- diagnosis of SCD performed by electrophoresis or HPLC in a reference laboratory for hemoglobinopathies
- patients older than 6 years and younger than 25 at inclusion
- clinically in a steady state at inclusion (without complication during the last month and without transfusion in the three last months)
- patients followed up for SCD at the sickle cell center of Guadeloupe (University hospital of Guadeloupe, Pointe-à-Pitre)
- patients or legal representatives of minors who will provide written informed consent in accordance with the Declaration of Helsinki
- patients affiliated to national social security
- the control group (AA subjects) will be recruited among volunteers recruited by posters
Who cannot join
- patients with SS or SC SCD or controls with hemoglobin AA
- diagnosis of SCD performed by electrophoresis or HPLC in a reference laboratory for hemoglobinopathies
- patients older than 6 years and younger than 25 at inclusion
- clinically in a steady state at inclusion (without complication during the last month and without transfusion in the three last months)
- patients followed up for SCD at the sickle cell center of Guadeloupe (University hospital of Guadeloupe, Pointe-à-Pitre)
- patients or legal representatives of minors who will provide written informed consent in accordance with the Declaration of Helsinki
- patients affiliated to national social security
- the control group (AA subjects) will be recruited among volunteers recruited by posters
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Guadeloupe1 site, 1 recruiting
- Recruiting
Chu de La Guadeloupe
Pointe-à-Pitre, 97159
Maryse etienne julan, MD, +590590934670, maryse.etienne-julan@chu-guadeloupe.fr
Maryse Etienne-Julan, MD PhD
About this study
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.
Read the detailed description
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.
- Keywords
- extracellular vesicles, blood immune cells, Dengue virus
- Medical subject headings
- Dengue, Virus Diseases, Fever, Anemia, Sickle Cell
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Patients SS Group | Fifty SS patients | |
| Patients SC | Fifty SC patients | |
| Control group AA | Patients without hemoglobin disease |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: baseline
Secondary outcomes (3)
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
Measured: 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
Measured: 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.
Measured: baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jun 2025
- Study start24 Jun 2024
- Primary completion24 Jun 2026 (estimated)
- Study completion24 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dengue (Virus); Fever, SandflyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 130 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Universitaire de la Guadeloupe
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Maryse Etienne-Julan, MD PhD, Principal investigator, CHU de la Guadeloupe
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07000747
- Sponsor's protocol ID
- PAP_RIPH3_2023/09
- Other IDs
- 2019-A03033-54
- Acronym
- DREPADENGUE
- Status last verified
- May 2025
- First submitted
- 21 May 2025
- Last updated
- 3 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Molecular and Cellular Basis of Severe Forms of Dengue in Sickle Cell Patients
- ClinicalTrials.gov ID
- NCT07000747
- Acronym / sponsor ID
- DREPADENGUE / PAP_RIPH3_2023/09
- Keywords
- extracellular vesicles, blood immune cells, Dengue virus
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 130 participants (estimated)
- Lead sponsor
- Centre Hospitalier Universitaire de la GuadeloupeUniversity, hospital or other
- Study start
- 24 Jun 2024 (actual)
- Primary completion
- 24 Jun 2026 (estimated)
- Study completion
- 24 Jun 2026 (estimated)
- First posted
- 3 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Patients SS Group | – | –Fifty SS patients |
| Patients SC | – | –Fifty SC patients |
| Control group AA | – | –Patients without hemoglobin disease |
Who may qualify
- Ages
- 6 to 25 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- patients from 6 to 25 years, with sicke cell disease in a steady state at inclusion
Key inclusion criteria (8 listed)
- patients with SS or SC SCD or controls with hemoglobin AA
- diagnosis of SCD performed by electrophoresis or HPLC in a reference laboratory for hemoglobinopathies
- patients older than 6 years and younger than 25 at inclusion
- clinically in a steady state at inclusion (without complication during the last month and without transfusion in the three last months)
- patients followed up for SCD at the sickle cell center of Guadeloupe (University hospital of Guadeloupe, Pointe-à-Pitre)
Key exclusion criteria (8 listed)
- patients with SS or SC SCD or controls with hemoglobin AA
- diagnosis of SCD performed by electrophoresis or HPLC in a reference laboratory for hemoglobinopathies
- patients older than 6 years and younger than 25 at inclusion
- clinically in a steady state at inclusion (without complication during the last month and without transfusion in the three last months)
- patients followed up for SCD at the sickle cell center of Guadeloupe (University hospital of Guadeloupe, Pointe-à-Pitre)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Lymphocyte subpopulations measured by flow cytometry at steady-state
Time frame: baseline
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.
3 secondary outcomes
activation status of immune cells induced by DENV
Time frame: baseline
Comparative Analysis of NET Formation Induced by Sickle Cell-Derived Microparticles With or Without Mosquito Saliva
Time frame: baseline
Impact of SS and SC Blood Profiles on Aedes aegypti Biting Behavior and Dengue Virus Transmission
Time frame: baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jun 2025.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Maryse Etienne-Julan, MD PhD principal investigator
CHU de la Guadeloupe
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Dengue (Virus); Fever, Sandfly and Sickle Cell Disease, run by Centre Hospitalier Universitaire de la Guadeloupe at 1 site in Guadeloupe.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Guadeloupe. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Valérie Hamony Soter (+590590934677, valerie.soter@chu-guadeloupe.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Lymphocyte subpopulations measured by flow cytometry at steady-state (time frame: baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Jun 2025.