View clinical trials related to Platelet Activation.
Filter by:The investigators would like to analyze platelet/leukoplak activation, quantify and morphologically characterize these aggregates using in vitro analysis, directly on whole blood from adult patients with suspected HIT. This would enable to better describe the in vivo pathophysiology of the HIT-suspect patient, and eliminate the need for platelet donors to perform the usual confirmatory techniques, whose inter- and intra-individual variability is very high. What's more, the SRA test, evaluated as the reference test, requires the use of radioisotopes and is therefore only carried out in a few biological expertise centers, resulting in a very long delay in the delivery of results. It should also be noted that, in practice, HÉPARINE is immediately stopped in patients with suspected HIT, and they are put on an expensive anticoagulant (DANAPAROIDE SODIQUE or ARGATROBAN) in curative doses until the results of the confirmatory tests are back. In this serious, life-threatening condition, it is essential to have a sensitive, specific test to confirm HIT as quickly as possible. Each patient with suspected HIT (rapid >30% reduction in platelet count after initiation of heparin therapy) should have 4 tubes of 3.2% citrated whole blood (2.7ml) collected at the time of suspected HIT (D0) and before any therapeutic switch (or 24 h max after switch). A new sample (4 citrated tubes) will be taken at D4, D7 and D14 during hospitalization, in patients who test positive for anti-PF4/H Ac. All patients with suspected HIT will follow the standard diagnostic pathway, i.e. a screening test (immunological test for anti-PF4/heparin antibodies, total Ig, ACL TOP, Werfen) followed by a confirmatory test (platelet aggregation on TA-8V, STAGO and/or SRA). Doppler ultrasonography of the lower limbs will be performed in HIT-suspect patients with a positive anti-PF4/H antibody test, as currently performed as part of routine care.
Sickle cell disease (SCD) is an autosomal recessive genetic disorder linked to a single mutation on beta-globin chains. This leads to red blood cell deformation and chronic hemolysis which can result in vaso-occlusive events, anemia and vasculopathy. Pathophysiology is incompletely understood, and beyond red blood cell's abnormalities this involves hemostasis and innate immunity. The aim of our study is to describe the mechanisms of thrombo-inflammation during the vaso-occlusive crisis (VOC) in adults with sickle cell disease.
In the case of cardiovascular diseases such as coronary artery disease, cerebrovascular disease, and peripheral arterial disease, there are many studies that the use of antiplatelet agents is very helpful in improving the vascular patency rate, but there are not many studies on the use of antiplatelet agents in the dialysis approach. The basis for use is insufficient. There is a lack of research on whether maintaining a state in which platelet activation is suppressed is helpful in improving dialysis access patency. Therefore, we conducted this study to determine whether the degree of platelet activation affects the patency of vascular access.
Platelets are essential blood elements to maintain hemostasis. Quantitative or qualitative defects can be responsible of hemorrhagic (platelet disorders) or thrombotic (heparin induced thrombocytopenia [HIT]) troubles. Diagnosis of these pathologies is sometimes urgent and consists in delicate platelet functional assays that are mostly made in expert centers. These platelets functional assays measure platelets activation and/or aggregation in response to diverse inductors and may lack sensitivity. The investigators would like to propose a new diagnostic tool with the use of imaging flow cytometry which provides much more information than classic cytometer on cell morphology thanks to images collected by the optical channel of the ImageStream cytometer. The use of this cytometer offers an innovative approach. This study is a monocentric prospective and non-interventional study. The investigators will analyze patient samples with the ImageStream cytometer and reference laboratory tests (light transmission aggregometry and serotonin release assay) in parallel and compare results from the different techniques. This new diagnostic technique will demonstrate a non-inferiority diagnosis compared to reference tests and maybe a better sensibility.