PB0130 - Platelet function evaluation by flow cytometry in patients taking dual antiplatelet therapy (DAPT)

Sunday, June 23, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

Ratchaneekorn Jantasing, Bachelor's degree of science (Medical technology)

Medical technologist
Division of Hematology, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital Bangkok, Thailand
Bangkok, Krung Thep, Thailand

Co-Author(s)

Ponlapat Rojnuckarin, MD, PhD

Professor
Excellence Center in Translational Hematology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Bangkok, Krung Thep, Thailand
PJ

Pakrit Jittapiromsak

neurological surgery
Department of Surgery; Faculty of Medicine; Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok,
bangkok, Krung Thep, Thailand
WA

Wasan Akarathanawat

neurological surgery
Chulalongkorn Stroke Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society. Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
bangkok, Krung Thep, Thailand
DA

Dollapak Apipongrat Apipongrat

Medical Technology
Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand
bangkok, Krung Thep, Thailand
ON

Oytip Nathalang

Professor
Graduate Program in Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand
bangkok, Krung Thep, Thailand

Background:

Introduction: Platelet aggregometry is a standard method for detecting antiplatelet resistance that is related to poor outcomes after antiplatelet therapy. Flow cytometry can measure other aspects of platelet functions, e.g. alpha-granule and dense granule release using CD62P and CD63 expression, respectively.

Aims:

Aim: To explore roles of flow cytometry for investigations of antiplatelet resistance

Methods:

Method: Patients who had unruptured intracranial aneurysm with plans for intravascular stenting and received clopidogrel 75 mg/d and aspirin 80-300 mg/d for 1 week were enrolled. Thirty healthy volunteers were served as controls. Blood samples were subjected to ADP- and arachidonate-induced platelet aggregation (% aggregation) and flow cytometry for ADP-induced CD62P and CD63 expression (Expression ratio between resting and stimulated platelets). The definitions of antiplatelet resistance were aggregation >42.9% (5 uM ADP) or >64.5% (20uM ADP) for clopidogrel and >20% (1.5 mM Arachidonate) for aspirin.

Results:

Results: Twenty-two of the control group were female with the mean age of 38.2±15.2 (SD) years. The ADP-induced CD62P expression ratio was not significantly correlated with the platelet aggregation (P0.427). Some healthy volunteers showed very high CD62P (Figure 1).
The patient group (N=30) had the mean age of 55.7±14.3 years and 70% were female. Clopidogrel resistance was found in 23.3% while no aspirin resistance was detectable by platelet aggregometry. The correlation coefficients of ADP-induced aggregation versus CD62P and CD63 expression were 0.411 (P0.024) and 0.116 (P0.541), respectively. The CD62P expression was higher in patients with clopidogrel resistance (2.79±0.81 vs. 1.90±0.82, P 0.021), while the difference of CD63 was not significant. The sensitivity and specificity of CD62P for diagnosing clopidogrel resistance were 71.4% and 91.3%, respectively.

Conclusion(s):

Conclusion: Clopidogrel resistance is common in Thais taking antiplatelet. CD62P showed moderate correlation with platelet aggregation in these patients, while CD63 yielded lower diagnostic values. The outcome correlations with the flow cytometry results are to be determined.