Arachidonic acid-stimulated platelet tests: Identification of patients less sensitive to aspirin treatment.
Serum thromboxane-B2 (TxB2), together with arachidonic acid (AA)-induced platelet aggregation, are, at the moment, the most used tests to identify patients displaying high on-aspirin treatment platelet reactivity (HAPR). Both tests are specific for aspirin action on cyclooxygenase-1. While the correlation between serum TxB2 assay and clinical outcome is established, data are conflicting with regard to aspirin treatment and a possible association with AA-stimulated platelet markers and clinical outcome. To understand such discrepancy, we performed a retrospective study to compare both assays. We collected data from 132 patients receiving a daily dose of aspirin (100 mg/day) and data from 48 patients receiving aspirin on alternate days. All Patients who received a daily dose of aspirin were studied for AA-induced platelet aggregation together with serum TxB2 levels and AA-induced TxB2 formation was also studied in 71 patients out of entire population. Consistent with recommendations in the literature, we defined HAPR by setting a cut-off point at 3.1 ng/ml for serum levels of thromboxane B2 and 20% for AA-induced platelet aggregation. According to this cut-off point, we divided our overall population into two groups: (1) TxB2 < 3.1 ng/ml and (2) TxB2 > 3.1 ng/ml. We found low agreement between such tests to identify patients displaying HAPR. Our results show that AA-induced platelet aggregation >20% identify a smaller number of HAPR patients in comparison with TxB2. A good correlation between serum TxB2 and arachidonic acid-induced TxB2 production was found (r = 0.76619).
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Flavia
F
Temperilli
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Aldona
A
Rina
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Isabella
I
Massimi
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Anna Lisa
AL
Montemari
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Maria Luisa
ML
Guarino
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Alessandra
A
Zicari
a Department of Experimental Medicine , "Sapienza" University of Rome , Rome , Italy.
Fabio M
FM
Pulcinelli
D000368:Aged; D000369:Aged, 80 and over; D016718:Arachidonic Acid / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology* / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D010979:Platelet Function Tests; D012189:Retrospective Studies; D013929:Thromboxane B2 / Q000097:blood / Q000378:metabolism
D010975:Platelet Aggregation Inhibitors; D016718:Arachidonic Acid; D013929:Thromboxane B2; D001241:Aspirin
Arachidonic acid; COX-1; aspirin; platelet aggregation; thromboxane B2