The contribution of platelet glycoproteins (GPIa C807T and GPIba C-5T) and cyclooxygenase 2 (COX-2G-765C) polymorphisms to platelet response in patients treated with aspirin.

Aspirin is an antiplatelet agent commonly used in treatment of patients with high risk to develop stroke and myocardial infarction. However, inter-individual variability regarding the inhibition of platelet function by aspirin is well documented. In this study, the correlation between platelet glycoproteins (GPIa C807T and GPIba C-5T) and cyclooxygenase 2 (COX-2G-765C) polymorphisms and antiplatelet response in patients treated with aspirin was investigated. Jordanian adult patients (n=584) who are taking aspirin as an antiplatelet agent participated in the study. Platelet aggregation response was measured using Multiplate Analyzer® system. Polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP) was used for genotyping of the examined polymorphisms. Aspirin resistance was found in 15.8% of patients. Response to aspirin was significantly associated with GPIba C-5T polymorphism (P<0.05). However, the GPIa C807T and COX-2G-765C polymorphisms were not related to aspirin resistance (P>0.05). A considerable fraction of the Jordanian population is resistant to the antiplatelet effect of aspirin, which might be related to GPIba C-5T polymorphism.