An observational study in Sickle Cell Disease (SCD), sponsored by Centre Hospitalier Universitaire de la Guadeloupe. Not yet recruiting at 1 site in Guadeloupe. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-05-25.
Sponsored by Centre Hospitalier Universitaire de la Guadeloupe · Observational
Sickle cell disease (SCD) is characterized by chronic hemolytic anemia, painful crisis called vaso-occlusive crisis (VOC) and chronic inflammation. Activated platelets of SCD patients participated to both chronic inflammation and painful VOC. Platelets are anucleated cells from the fragmentation of megakaryocytes in bone marrow.
The main aim of this study is to characterize the distribution of the different megakaryocyte subpopulations of sickle cell disease patients SS and SC and in particular the "immune" megakaryocytes CD148+CD48+ and to compare it with the platelet phenotype.
Platelets are activated in all sickle cell disease patients at baseline with higher expression of selective P (CD62P). Platelets provide a major function in primary hemostasis by the formation of the platelet clot and also participate in coagulation through the formation of an electro-negative phospholipid surface essential to the enzymes of the coagulation cascade. It is now known that platelets are also immune cells that are able to secrete pro-inflammatory cytokines (TGF beta, IFN gamma), that they express certain Toll-like receptors (TLR4) and the inflammasome NLRP3 leading to the activation of caspase-1. Several teams, including ours, have shown that inflammasome and/or caspase-1 can be activated in an infectious context, particularly viral (dengue fever, COVID) and inflammatory (chronic inflammatory bowel diseases, etc.).
Platelets are anucleated cells from the fragmentation of megakaryocytes. Their protein profile is therefore the result of bone marrow differentiation of megakaryocytes. Recently, it has been shown a cellular heterogeneity within megakaryocytes including immune megakaryocytes whose proportion can significantly increase in stress and inflammation condition. It is not clear whether these immune megakaryocytes that could behave as antigen-presenting cells are capable of producing blood platelets.
We wonder whether sickle cell disease patients have a different proportion of these immune megakaryocytes compared to healthy subjects and whether their activated blood platelets carry specific markers of these immune megakaryocytes.
SCD patients will be recruited in the active file of the sickle cell center of Guadeloupe. Two groups of patients will be constituted: SS patients and SC patients. The control group will be composed of patients who come for hip or knee replacement and do not suffer from chronic disease. Only one blood and bone marrow collection will be realized during the study.
1,134 studies on the registry are indexed under Anemia, Sickle Cell; 238 are open to participants now.
This study's planned enrollment of 100 is close to the median of 100 across 296 observational studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell 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 with sockle celle disease are patients who come for their disease. Control group are patients who come at the University hospital of Guadeloupe (Pointe à Pitre), for hip or knee replacement and will do not suffer from chronic disease.
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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.
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.
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.
patients with SS sickle cell disease
patients with SC sickle cell disease
patient without sickle cell disease (AA hemoglobin)
proportion of immune megakaryocytes CD148+CD48+ in bone marrow
The primary outcome will be the evaluation of the proportion of immune megakaryocytes CD148+CD48+ in bone marrow of sickle cell disease patients in comparison to control group.
Time frame: 24 months
platelet phenotype
The secondary outcomes are to compare the platelet phenotype between the three groups of patients, including the proportion of CD148+CD48+ platelets, to study the activation of this platelet subpopulation (expression of CD62P) and establish whether there is a relationship between the proportion of immune megakaryocytes in the bone marrow and the proportion of CD148+CD48+ platelets in the blood.
Time frame: 24 months
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Jul 2025; primary completion for Mar 2027, 20 months later.
Of 130 non-industry observational studies under Anemia, Sickle Cell, half reached primary completion within 48 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 109. This study's planned 20 months is below that.
Counting every sponsor, half of 139 studies reached it within 49 months; a quarter within 24 and three quarters within 109.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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Centre Hospitalier Universitaire de la Guadeloupe