Platelet aggregation.
Doctors of the clinical diagnostic laboratory VITAMED MEDICAL Ishmakova Regina Ramzizovna and Khodzhaeva Nargiza Temirovna will introduce you to an article on the topic “Platelet aggregation. What is this? Why are they researching?
Platelets are the smallest blood cells (compared to leukocytes and red blood cells), which perform the most important function - they protect the body from blood loss. Platelet aggregation is the process of cells sticking together, which is the first stage in the formation of a blood clot.
The second stage is the attachment of platelets to the wall of the damaged vessel. Fibrin threads, other elements, and new adherent cells are layered onto the platelet mass. Thus, the thrombus grows to a size capable of blocking the diameter of the vessel and stopping bleeding. Sometimes a person’s life depends on the speed of the process.
The role of platelet aggregation in the process of blood clotting
Blood clotting depends on many factors. One of them is platelet aggregation, which has a protective adaptive nature in a healthy body. Cells stick together only in a bleeding vessel. In this case, the process plays a positive role.
But there are known pathological conditions in which the formation of blood clots is undesirable, since it leads to disruption of nutrition of vital organs.
For example,
Medicines
Platelet dysfunction can be caused by aspirin and other NSAIDs, as well as platelet receptor P2Y12 ADP inhibitors (eg, clopidogrel, prasugrel, ticagrelor). Sometimes this occurs accidentally (for example, when drugs are intended to relieve pain and inflammation), and sometimes for therapeutic purposes (for example, when aspirin or P2Y12 inhibitors are used to prevent stroke or coronary thrombosis).
Aspirin and NSAIDs prevent the production of cyclooxygenase-mediated thromboxane A2. The effect can last from 5 to 7 days. Aspirin slightly increases bleeding in healthy people, but it may also markedly increase bleeding in patients with underlying platelet dysfunction or severe coagulation impairment (eg, patients treated with heparin or patients with severe hemophilia). Clopidogrel, prasugrel and ticagrelor may markedly reduce platelet function and increase bleeding.
Various diseases
Myocardial infarction, stroke, leading artery thrombosis, myeloproliferative syndrome and myelodysplastic disorders, uremia, macroglobulinemia, multiple myeloma, cirrhosis, SLE can worsen platelet function. The aggregation activity of platelets takes the side of pathological changes. You have to fight against it with the help of various medications.
Artificial circulation
Because blood is circulated through the oxygenator pump bypass during cardiopulmonary bypass, platelets can become dysfunctional, prolonging bleeding. The mechanism is activation of fibrinolysis on the platelet surface with resulting loss of glycoprotein Ib/IX, the binding site for von Willebrand factor. Regardless of platelet count, platelet transfusions are often given to patients with severe bleeding following cardiopulmonary bypass. Administration of aprotinin (a protease inhibitor) during shunting may preserve platelet function and reduce the need for transfusions.
Method of determination
There is a practical need to quantify good and bad platelet aggregation. To do this, you need to use the norm and distinguish deviations.
In the VITAMED MEDICAL Laboratory, platelet aggregation is determined using the INNOVANCE PFA-200 analyzer. This is a unique device that simulates the process of blockage of a vessel when it is damaged, to quantitatively assess the hemostatic function of platelets. Simulation of the process of vessel damage occurs in vitro in a unique cartridge with a special channel; the channel has holes that simulate damage to the vessel wall, which activates the coagulation process, since these holes are covered with collagen and agonists, which trigger coagulation.
The analyzer evaluates:
- Functions of von Willebrand factor - Collagen - Epinephrine - for screening
- Aspirin effect - Collagen-ADP – to determine the effect of acetylsalicylic acid
- Determining the presence of P2Y12 platelet receptor blockade in patients undergoing antagonist treatment. P2Y12
Rules for preparing for analysis
To take a blood test for aggregation ability, you need to understand that the test will be inaccurate if the preparation rules are violated. There will be substances in the blood that affect the result.
A week before donating blood, all aspirin medications, Dipyridamole, Indomethacin, Sulfapyridazine, and antidepressants should be discontinued. The use of these drugs inhibits (suppresses) thrombus formation. If you cannot stop taking it, you should inform the laboratory technician.
You can’t eat for at least 12 hours; eating fatty foods especially affects the test results.
The patient should be as calm as possible and not perform physical work before taking the test.
The day before the test, exclude coffee, alcohol, garlic from food and do not smoke.
The analysis is not performed if there is an active inflammatory process.
Before undergoing the analysis, you can consult with cardiologists at the VITAMED MEDICAL clinic.
You can ask any questions you are interested in by sending a request by email or by contacting us by phone:
info@vitamed.uz
(+998 71) 129-81-81; (+998 71) 129-82-82
Additional information:
www.vitamed.uz
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Ambulance – 1063, (+998 71) 129-00-03
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