Megakaryocyte Heterogeneity in Sickle Cell Disease
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Простыми словами
Автоматическая сводка по структурированным данным реестра. Она помогает сориентироваться, но не заменяет официальный протокол или оценку врача.
- Что изучают
- Это наблюдательное исследование: исследуемое лечение участникам по протоколу не назначают.
- Кому может быть актуально
- Состояния в реестре: Sickle Cell Disease (SCD). Базовые параметры: от 18 лет · Все.
- Что важно проверить
- Возраст, диагноз и пол — только базовые ориентиры. Предыдущее лечение, анализы и другие обязательные условия указаны ниже в критериях участия.
- Где проводится
- Guadeloupe
- Следующий шаг
- Сохраните исследование, покажите его лечащему врачу и уточните актуальный статус у исследовательского центра. Расходы, документы и поездка →
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Официальное название
Characterization of Megakaryocytic Subpopulations and the "Immune" Phenotype of Platelets of the Sickle Cell Disease Patient
Обзор
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.
Подробное описание
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.
Первичные конечные точки
- proportion of immune megakaryocytes CD148+CD48+ in bone marrow [Срок оценки: 24 months]
Вторичные конечные точки (1)
- platelet phenotype [Срок оценки: 24 months]
Критерии участия
Критерии включения
- patients with SS or SC SCD
- diagnosis of SCD performed by electrophoresis or HPLC in a reference laboratory for hemoglobinopathies
- patients older than 18 years at inclusion
- clinically in a steady state at inclusion (without complication in the last month and without 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)
- patients 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 patients older than 18 years old who come at the University hospital of Guadeloupe, (Pointe à Pitre) for hip or knee replacement and will do not suffer from chronic disease.
Критерии исключения
- patients younger than 18 years old
- patients with hemoglobinopathy other than SS and SC SCD
- patients with a transfusion therapy or on bleeding therapy for less than three months
- patients no affiliated to national social security
- pregnant or breastfeeding patients
Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.
Здоровые добровольцы: Да
Дизайн исследования
- Модель наблюдения
- Другое
Центры проведения
Guadeloupe · 1 центр
- Chu de La Guadeloupe — Pointe-à-Pitre
Идентификаторы
NCT: NCT06850337 · PAP_RIPH2_2024/04 · 2024-A01093-44