Measurement of platelet aggregation with ADP

Measurement of platelet aggregation with ADP is one of the important factors in assessing platelet activity, as well as in part in the effectiveness of antiplatelet drugs.

Platelets are a fragment of cells without a nucleus made from a sample of mature platelets in the bone marrow. Platelets play important roles in many processes including blood clotting, clot contraction, clot formation, vasoconstriction and repair, immunity, inflammation, atherosclerosis.
Platelets perform many functions, among which the function related to blood clotting is of most interest and most platelet function tests are intended to investigate this function. When platelets participate in the hemostasis process, the platelets must undergo an activation phase to release substances in the functional granules and change shape to stick together to form a platelet plug and clot. .
Therefore, when the patient has bleeding manifestations but the platelet count is still within normal limits, or in a number of diseases such as ischemic heart disease, hypertension, dyslipidemia... Then your doctor will order a test to measure the platelet aggregation.

2.1 Overview Platelet aggregation is one of the important factors to evaluate the activity of platelets as well as to assess the effectiveness of antiplatelet drugs.
Measurement of platelet aggregation by machine when platelets are exposed to ADP factor, at this time platelets are activated and aggregate together into granules, and change the optical density or impedance of the flow electricity. The degree of condensation change is reflected in the degree of change in optical density or impedance.
Measurement of platelet aggregation is indicated in cases of bleeding when platelets are normal.
2.2 Procedure The patient should have blood drawn, preferably on an empty stomach. The medical staff will draw venous blood with a plastic syringe, then put the blood into the anticoagulation tube with 3.8% sodium citrate in the ratio of 1 volume of anticoagulation mixed with 9 volumes of blood. Centrifuge platelet-rich plasma and platelet-poor plasma. In some cases, whole blood can be used for testing.

The blood is then brought to the laboratory. Before measuring, it is necessary to ensure that the blood does not clot, the steps to measure platelet aggregation include:
Step 1: Turn on the computer, the platelet condenser, wait for the machine to have enough temperature for 10 minutes. Aspirate each 500 μl cuvette, pay attention to the platelet-rich cuvettes with magnetic stirrer, and incubate the cuvettes in the machine's incubation well for 5 min. Step 2: Start AGGRO LINK software Step 3: Press RUN NEW key, enter patient name or ID, name and type of test, end with OK key Step 4: Set BASELINE: put patient's plasma freeze in position position, press the SET BASELINE key, let the curve change from 0 to 100%, wait for the machine to stabilize for 1-2 minutes, press STOP Step 5: Reconfirm all patient information Step 6: Press RUNREXT Step 7 : Drop chemicals into the condenser with collagen: 1 μl collagen, the condenser with ADP: 5 μl ADP. Step 8: Observe the graph to saturation then press STOP Step 9: Enter the SET START & STOPTIME function Step 10: Press CALCULATE RESULTS to calculate the result Step 11: Print the result, turn off the meter, clean the meter. The results of the measurement of platelet aggregation are expressed in terms of maximum aggregation, the slope of the aggregation curve, time to onset of aggregation, and time from onset of aggregation to reaching maximal aggregation. multi. Platelet aggregation is expressed as the most commonly used maximum concentration.
The normal value of platelet aggregation will depend on the type of machine, and the concentration of the stimulant. Each laboratory will have its own normal value.
Platelet aggregation is one of the important factors to evaluate platelet activity, platelet aggregation is indicated in the case of bleeding when platelets are normal to assess platelet activity. , as well as to some extent in the effectiveness of antiplatelet agents.
SEE ALSO:
Symptoms and complications of immune thrombocytopenic purpura Diagnosing and treating immune thrombocytopenic purpura The role of red blood cells, platelets, and white blood cells in the body