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Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Clopidogrel affects leukocyte dependent platelet aggregation by P2Y12 expressing leukocytes
Philipp Diehl1, Christoph Olivier, Christoph Halscheid
1Department of Cardiology and Angiology, University-Hospital Freiburg, 79106 Freiburg, Germany.
Basic Research in Cardiology
|November 28, 2009
Summary
Many patients lack sufficient response to antiplatelet therapy after coronary stent placement, increasing thrombotic risks. This study reveals leukocytes influence clopidogrel response, suggesting potential underdosing in obese patients.
Area of Science:
- Cardiology
- Pharmacology
- Immunology
Background:
- Suboptimal response to antiplatelet therapy affects up to 30% of patients with coronary stents.
- This non-responsiveness elevates the risk of thrombotic complications, including stent thrombosis and myocardial infarction.
- Understanding factors influencing antiplatelet drug efficacy is crucial for improving patient outcomes.
Purpose of the Study:
- To identify clinical parameters that modulate aspirin (ASA) and clopidogrel responsiveness.
- To investigate the role of leukocytes in platelet aggregation and drug response.
- To explore potential mechanisms of clopidogrel action and dosing considerations.
Main Methods:
- Whole blood aggregation was measured using impedance aggregometry (Multiplate device).
- Aspirin (ASA) responsiveness was assessed using arachidonic acid (AA) stimulation.
- Clopidogrel responsiveness was assessed using adenosine diphosphate (ADP) stimulation.
- P2Y(12) receptor expression on leukocytes was determined by RT-PCR.
Main Results:
- ADP-induced platelet aggregation correlated with leukocyte count, indicating functional platelet-leukocyte interaction.
- Clopidogrel treatment diminished the influence of leukocytes on platelet aggregation and reduced leukocyte activation.
- The P2Y(12) receptor, clopidogrel's target, was detected on leukocytes, suggesting direct action on these cells.
- Clopidogrel response, unlike ASA response, correlated with body mass index, with a potential underdosing in obese patients.
Conclusions:
- Leukocytes significantly influence ADP-induced platelet aggregation via P2Y(12) receptor expression, an effect mitigated by clopidogrel.
- Clopidogrel may exert direct effects on leukocytes through the P2Y(12) receptor.
- Obesity may be associated with reduced clopidogrel efficacy, potentially necessitating dose adjustments.
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