Anna Lisa Montemari

Arachidonic acid-stimulated platelet tests: Identification of patients less sensitive to aspirin treatment

Abstract 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).

Validation of biomarkers of diabetic retinopathy for preventing and predictive medicine in diabetic complications

Scientific object The epidemic diffusion of diabetes mellitus has raised serious concerns about the deleterious effects of its complications. Diabetic retinopathy (DR) is a severe progressive ocular pathology and the leading cause of blindness in adults. There is a significant limitation in specific biomarkers for DR, thus, implying that DR diagnosis occur when vision is already compromised. Poor glycemic control, with elevated hemoglobin A1c (HbA1c), and hypertension are recognized risk factors, however the implication of inflammatory processes in DR pathogenesis has prompt interest in the identification of biomarkers of disease within the immune system.