title: 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.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  A considerable fraction of the Jordanian population is resistant to the antiplatelet effect of aspirin, which might be related to GPIba C-5T polymorphism.
authors.affiliation: Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan. sayerazzam@yahoo.com
authors.forename: Sayer I
authors.initials: SI
authors.lastname: Al-Azzam
authors.forename: Karem H
authors.initials: KH
authors.lastname: Alzoubi
authors.forename: Omar F
authors.initials: OF
authors.lastname: Khabour
authors.forename: Deniz
authors.initials: D
authors.lastname: Tawalbeh
authors.forename: Ola
authors.initials: O
authors.lastname: Al-Azzeh
mesh_terms: D000368:Aged; D000483:Alleles; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics*; D004351:Drug Resistance / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D039421:Integrin alpha2 / Q000235:genetics*; D007597:Jordan; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects / Q000235:genetics; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D019038:Platelet Glycoprotein GPIb-IX Complex; D010980:Platelet Membrane Glycoproteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
chemical_list: D039421:Integrin alpha2; D008562:Membrane Glycoproteins; D010975:Platelet Aggregation Inhibitors; D019038:Platelet Glycoprotein GPIb-IX Complex; D010980:Platelet Membrane Glycoproteins; C094990:adhesion receptor; D051546:Cyclooxygenase 2; D001241:Aspirin
keywords: Antiplatelet resistance; BMI; Body mass index; COX; COX 2; Cyclooxygenase 2; Cyclooxygenases; GPIIb/IIIa; GPIa; GPIbα; Glycosylated hemoglobin; HbA1(C); Jordan; MI; Myocardial infarction; NSIADs; Nonsteroidal antiinflammatory drugs; PCR–RFLP; Platelet glycoprotein IIb/IIIa; Platelet glycoprotein Ia; Platelet glycoprotein Ibα; Polymerase chain reaction restriction fragment length polymorphism; Polymorphism; Restriction fragment length polymorphism; SNPs; SPSS; Statistical Package for the Social Sciences; TIA; TXA2; Thromboxane A2; Transient ischemic attack; VWF; Von Willebrand factor; single nucleotide polymorphisms