Sickle Cell DiseaseDrepAgregNCT07852442
Comparison of Thrombin Generation, Platelet Activation and Aggregation Profiles in Patients With Sickle Cell Disease Depending on Their SS or SC Genotype (DrepAgreg)
An observational study of Sickle Cell Disease and Venous Thromboembolism, run by Centre Hospitalier Universitaire de la Guadeloupe at 2 sites in 2 countries.
Trial summary
Sickle cell disease (SCD) is characterized by chronic hemolytic anemia, painful crises called vaso-occlusive crises (VOC) and chronic inflammation. Activated platelets from SCD patients contribute to both chronic inflammation and painful VOC. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Sickle Cell Disease, Venous Thromboembolism
- How many people
- 60 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 15 Oct 2026to 15 Oct 2028
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with sickle cell disease and the HbSS or HbSC genotype recruited from the participating study centers in Guadeloupe or Bobigny
Who may be able to join
- SCD patients with SS or SC
- diagnosis of SCD performed by electrophoresis or high-performance liquid chromatography (HPLC) in a reference laboratory for hemoglobinopathies
- patients older than 18 years at inclusion
- clinically in a steady state at inclusion (no complication in the last month and no transfusion in the three last months)
- patient followed up for SCD at the sickle cell center of Guadeloupe (University hospital of Guadeloupe, Pointe à Pitre) or at the Adult Rare Diseases Reference Center "Sickle Cell Disease / Major Sickle Cell Syndromes" of the Avicenne hospital in Bobigny.
- patients who will provide written informed consent in accordance with the Declaration of Helsinki
- patients affiliated with national social security
Who cannot join
- patients younger than 18 years old
- patients with hemoglobinopathy other than SS and SC SCD
- patients who have received transfusion therapy or on bleeding therapy for less than three months
- patients no affiliated with national social security
- pregnant or breastfeeding patients
Trial locations and contacts
2 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
2 sites in 2 countries
France1 site
Hôpital Avicenne
Bobigny, 93000
Sylvain Lejeune, MD PhD, sylvain.le-jeune@aphp.fr
sylvain lejeune, MD PhD
Guadeloupe1 site
CHU de la Guadeloupe
Les Abymes, 97159
mélanie petapermal, 0590934667, melanie.petapermal@chu-guadeloupe.fr
melanie.petapermal@chu-guadeloupe.fr
About this study
Official title: Comparison of Thrombin Generation, Platelet Activation and Aggregation Profiles in Patients With Sickle Cell Disease Depending on Their SS or SC Genotype
Sickle cell disease (SCD) is characterized by chronic hemolytic anemia, painful crises called vaso-occlusive crises (VOC) and chronic inflammation. Activated platelets from SCD patients contribute to both chronic inflammation and painful VOC. Individuals with the HbSC genotype experience anemia and less severe clinical manifestations than those with the HbSS genotype; however, they are at higher risk of venous thromboembolic events, particularly pulmonary embolism.
This study aims to investigate whether sickle cell patients exhibit different thrombin generation profiles as well as distinct platelet activation and aggregation profiles, depending on their SS or SC genotype.
Read the detailed description
Sickle cell anemia is the most common genetic disease worldwide. It is due to a homozygous mutation in the beta globin gene leading to the production of abnormal hemoglobin S (HbS). This hemoglobin polymerizes and precipitates in the red blood cells (RBCs) under hypoxic conditions, leading to the rigidification of the red blood cells that obstruct the small vessels and are subsequently destroyed. The disease is thus characterized by chronic hemolytic anemia associated with painful vaso-occlusive crises (VOC) and chronic inflammation. The HbSC genotype is associated with anemia and less severe clinical manifestations than the HbSS genotype. However, the risk of venous thromboembolic events, particularly pulmonary embolism, is paradoxically higher. The pathophysiological mechanisms involved in the occurrence of VOC and venous thromboembolic events (VTE) have not been fully elucidated. They involve phenomena of ischemia-reperfusion and complex interactions between the RBC, the endothelium, the leucocytes and the platelets. The sickle RBCs express phosphatidylserine (PS) on their surface, which facilitates their adhesion to other blood cells and their interaction with the endothelium. The release of hemoglobin and free heme into the circulation, along with oxidative stress, induces endothelial activation and dysfunction, as well as vascular inflammation, platelet activation and clotting. Numerous studies have documented the existence of coagulation activation in sickle cell patients during the stable phase of the disease and during VOCs, decreased levels of physiological inhibitors of coagulation and resistance to activated protein C. One of the main mechanisms of coagulation activation in sickle cell patients is increased tissue factor expression on the surface of activated monocytes and endothelial cells. Free heme promotes NETs (neutrophil extracellular traps) formation, which activates the intrinsic coagulation pathway. Moreover, platelets probably play a pivotal role in the thrombo-inflammatory process, coagulation activation, and the occurrence of VOC and VTE. We hypothesize that sickle cell patients may exhibit a different thrombin generation profile as well as distinct platelet activation and reactivity profiles, depending on their SS or SC genotype.
- Conditions
- Sickle Cell Disease, Venous Thromboembolism
- Keywords
- Sickle cell disease, thrombin generation, platelet activation, aggregometry, platelets
- Medical subject headings
- Anemia, Sickle Cell, Venous Thromboembolism
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 |
|---|---|---|
| SS Group | Patients with sickle cell disease and an SS genotype. | |
| SC Group | Patients with sickle cell disease and an SC genotype. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Endogenous thrombin potential (ETP)
Thrombin generation profiles will be assessed in whole blood, plasma, and platelet-rich plasma. Endogenous thrombin potential will be compared between patients with sickle cell disease and an SS genotype and patients with sickle cell disease and an SC genotype
Measured: At baseline
Secondary outcomes (5)
Lag time of thrombin generation
Thrombin generation will be assessed in whole blood, plasma, and platelet-rich plasma. Lag time will be compared between patients with sickle cell disease and the HbSS genotype and those with the HbSC genotype.
Measured: At baseline
Time to peak thrombin generation
Thrombin generation will be assessed in whole blood, plasma, and platelet-rich plasma. Time to peak will be compared between patients with sickle cell disease and the HbSS genotype and those with the HbSC genotype.
Measured: At baseline
Peak height of thrombin generation
Thrombin generation will be assessed in whole blood, plasma, and platelet-rich plasma. Peak height will be compared between patients with sickle cell disease and the HbSS genotype and those with the HbSC genotype.
Measured: At baseline
Platelet activation profile
Platelet activation profiles will be assessed and compared between patients with sickle cell disease and the HbSS genotype and those with the HbSC genotype.
Measured: At baseline
Platelet aggregation profile
Platelet aggregation profiles will be assessed and compared between patients with sickle cell disease and the HbSS genotype and those with the HbSC genotype.
Measured: At baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2026
- Study start15 Oct 2026 (estimated)
- Primary completion15 Oct 2028 (estimated)
- Study completion15 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickle Cell DiseaseStudies 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
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Universitaire de la Guadeloupe
- Sponsor type
- University, hospital or other
- Collaborators
- Hospital Avicenne
- Responsible party
- Sponsor
- Investigators
- Véronique Baccini, MD PhD, Study director, chu de la guadeloupeSylvain Lejeune, MD PhD, Principal investigator, Centre de Référence Maladies Rares Adulte de Bobigny " Drépanocytose / syndromes drépanocytaires majeurs " de l'hôpital AvicenneMaryse ETIENNE JULAN, MD, Principal investigator, CHU de la Guadeloupe Coordonnateur, Centre de référence des syndromes drépanocytaires majeurs, thalassémies et autres pathologies rares du globule rouge et de l'érythropoïèse
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07852442
- Sponsor's protocol ID
- CHUG_RIPH2_2026/01
- Acronym
- DrepAgreg
- Status last verified
- Sep 2026
- First submitted
- 25 Sep 2026
- Last updated
- 1 Oct 2026
- 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 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Thrombin Generation, Platelet Activation and Aggregation Profiles in Patients With Sickle Cell Disease Depending on Their SS or SC Genotype
- ClinicalTrials.gov ID
- NCT07852442
- Acronym / sponsor ID
- DrepAgreg / CHUG_RIPH2_2026/01
- Conditions
- Sickle Cell Disease, Venous Thromboembolism
- Keywords
- Sickle cell disease, thrombin generation, platelet activation, aggregometry, platelets
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Centre Hospitalier Universitaire de la GuadeloupeUniversity, hospital or other
- Collaborators
- Hospital Avicenne
- Study start
- 15 Oct 2026 (estimated)
- Primary completion
- 15 Oct 2028 (estimated)
- Study completion
- 15 Oct 2028 (estimated)
- First posted
- 1 Oct 2026 (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.
Sickle cell disease (SCD) is characterized by chronic hemolytic anemia, painful crises called vaso-occlusive crises (VOC) and chronic inflammation. Activated platelets from SCD patients contribute to both chronic inflammation and painful VOC. Individuals with the HbSC genotype experience anemia and less severe clinical manifestations than those with the HbSS genotype; however, they are at higher risk of venous thromboembolic events, particularly pulmonary embolism.
This study aims to investigate whether sickle cell patients exhibit different thrombin generation profiles as well as distinct platelet activation and aggregation profiles, depending on their SS or SC genotype.
Detailed description
Sickle cell anemia is the most common genetic disease worldwide. It is due to a homozygous mutation in the beta globin gene leading to the production of abnormal hemoglobin S (HbS). This hemoglobin polymerizes and precipitates in the red blood cells (RBCs) under hypoxic conditions, leading to the rigidification of the red blood cells that obstruct the small vessels and are subsequently destroyed. The disease is thus characterized by chronic hemolytic anemia associated with painful vaso-occlusive crises (VOC) and chronic inflammation. The HbSC genotype is associated with anemia and less severe clinical manifestations than the HbSS genotype. However, the risk of venous thromboembolic events, particularly pulmonary embolism, is paradoxically higher. The pathophysiological mechanisms involved in the occurrence of VOC and venous thromboembolic events (VTE) have not been fully elucidated. They involve phenomena of ischemia-reperfusion and complex interactions between the RBC, the endothelium, the leucocytes and the platelets. The sickle RBCs express phosphatidylserine (PS) on their surface, which facilitates their adhesion to other blood cells and their interaction with the endothelium. The release of hemoglobin and free heme into the circulation, along with oxidative stress, induces endothelial activation and dysfunction, as well as vascular inflammation, platelet activation and clotting. Numerous studies have documented the existence of coagulation activation in sickle cell patients during the stable phase of the disease and during VOCs, decreased levels of physiological inhibitors of coagulation and resistance to activated protein C. One of the main mechanisms of coagulation activation in sickle cell patients is increased tissue factor expression on the surface of activated monocytes and endothelial cells. Free heme promotes NETs (neutrophil extracellular traps) formation, which activates the intrinsic coagulation pathway. Moreover, platelets probably play a pivotal role in the thrombo-inflammatory process, coagulation activation, and the occurrence of VOC and VTE. We hypothesize that sickle cell patients may exhibit a different thrombin generation profile as well as distinct platelet activation and reactivity profiles, depending on their SS or SC genotype.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| SS Group | – | –Patients with sickle cell disease and an SS genotype. |
| SC Group | – | –Patients with sickle cell disease and an SC genotype. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with sickle cell disease and the HbSS or HbSC genotype recruited from the participating study centers in Guadeloupe or Bobigny
Key inclusion criteria (7 listed)
- SCD patients with SS or SC
- diagnosis of SCD performed by electrophoresis or high-performance liquid chromatography (HPLC) in a reference laboratory for hemoglobinopathies
- patients older than 18 years at inclusion
- clinically in a steady state at inclusion (no complication in the last month and no transfusion in the three last months)
- patient followed up for SCD at the sickle cell center of Guadeloupe (University hospital of Guadeloupe, Pointe à Pitre) or at the Adult Rare Diseases Reference Center "Sickle Cell Disease / Major Sickle Cell Syndromes" of the Avicenne hospital in Bobigny.
Key exclusion criteria (5 listed)
- patients younger than 18 years old
- patients with hemoglobinopathy other than SS and SC SCD
- patients who have received transfusion therapy or on bleeding therapy for less than three months
- patients no affiliated with national social security
- pregnant or breastfeeding patients
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
Endogenous thrombin potential (ETP)
Time frame: At baseline
Thrombin generation profiles will be assessed in whole blood, plasma, and platelet-rich plasma. Endogenous thrombin potential will be compared between patients with sickle cell disease and an SS genotype and patients with sickle cell disease and an SC genotype
5 secondary outcomes
Lag time of thrombin generation
Time frame: At baseline
Time to peak thrombin generation
Time frame: At baseline
Peak height of thrombin generation
Time frame: At baseline
Platelet activation profile
Time frame: At baseline
Platelet aggregation profile
Time frame: At 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 1 Oct 2026.
- Individual participant dataSharing planned: No
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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.
Véronique Baccini, MD PhD study director
chu de la guadeloupe
Sylvain Lejeune, MD PhD principal investigator
Centre de Référence Maladies Rares Adulte de Bobigny " Drépanocytose / syndromes drépanocytaires majeurs " de l'hôpital Avicenne
Maryse ETIENNE JULAN, MD principal investigator
CHU de la Guadeloupe Coordonnateur, Centre de référence des syndromes drépanocytaires majeurs, thalassémies et autres pathologies rares du globule rouge et de l'érythropoïèse
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Sickle Cell Disease and Venous Thromboembolism, run by Centre Hospitalier Universitaire de la Guadeloupe at 2 sites in 2 countries.
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 7 inclusion and 5 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: opening soon, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in France, 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 mélanie petapermal, Master degree (0590934667 ext. +590, melanie.petapermal@chu-guadeloupe.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Endogenous thrombin potential (ETP) (time frame: At 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 1 Oct 2026.