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.
Dijon University Hospital and the Dijon-based NVH Medicinal Company have developed a recombinant mini-collagen NVH020B with platelet and Willebrand factor binding activity. Its small size and granular, non-fibrillar presentation make it suitable for use as an injectable hemostat in patients with a hemorrhage or other emergency under antiplatelet therapy.
The primary aim is to describe platelet function in adult patients treated with extracorporeal membrane oxygenation (ECMO). A clarification of the platelet function in these critically ill patients contributes to an understanding of the mechanisms underlying their coagulopathy. The present study is a substudy to the study entitled; "Coagulopathy During Extracorporeal Membrane Oxygenation" (pending Clinical Trial ID number).
Electronic cigarettes (E-cigarettes) and new heat-not-burn tobacco products such as IQOS®, an electronic device that heats a cigarette-like stick without combustion, are a modern and technological surrogate of traditional tobacco cigarettes (T-cigarettes), that are entering in the commercial market. While the negative effects of the traditional cigarette are well known, little data are reported in scientific literature on the risks on the health by these new smoking devices. Endothelial dysfunction evaluated by flow-mediated dilatation (FMD), oxidative stress and platelet activation have been recognized as a hallmark of preclinical systemic atherosclerosis and as a useful marker to stratify the risk of cardiovascular disease in patients at risk or with established clinically significant atherosclerosis. Since no data are reported about the effects of these new smoking device on oxidative stress, platelet activation and FMD, the investigators designed a human study assessing if these new smoking devices have effects on healthy smokers.
Low-dose aspirin is a cornerstone in the secondary prevention of cardiovascular disease (CVD) and is usually taken on awakening, although evidence regarding optimal time of intake is lacking. Platelet reactivity follows a circadian rhythm, with a peak in the morning, contributing to the morning peak of cardiovascular disease. Due to its short half life, aspirin only inhibits platelets which are present at the time of intake. Thus, the timing of aspirin intake may influence its inhibitory effect on platelets and intake of aspirin at bedtime may attenuate the morning peak of platelet reactivity. The time-dependent effect of aspirin on circadian rhythm of platelet function has never been studied before. We hypothesize that aspirin intake at bedtime compared with intake on awakening results in a reduction of the morning peak in platelet reactivity.