The effects of antiplatelet agents on platelet-leukocyte aggregations in patients with acute cerebral infarction

Background Studies have shown that platelet-leukocyte aggregates (PLA) are sensitive to platelet activation which might exist before the onset of cerebral infarction. In this study, we investigated the formation of PLA in patients with cerebral infarction and the effects of antiplatelet agents on PLA. Methods The level of soluble P-selectin, C-reaction protein, platelet aggregation rate and leukocyte-platelet aggregations were measured in 40 patients with acute cerebral infarction and 20 normal controls. The 40 patients were randomly assigned to two treatment groups: aspirin group (n = 20) and clopidogrel group (n = 20). Both groups were monitored for Scandinavian stroke scale (SNSS), soluble P-selectin, serum C-reaction protein, platelet aggregation rate and PLA before and after the treatment. Flow cytometry was used to detect the levels of PLA in the blood. Results The percentage of platelet-monocyte aggregates (PMA) in patients with cerebral infarction was significantly increased compared with the controls (P < 0.001), which was positively correlated to soluble P-selectin, C-reaction protein and platelet aggregation rate (P < 0.05). After the treatment, the levels of PMA and platelet aggregation rate were decreased in both groups (P < 0.05). The level of PMA and platelet aggregation rate in the clopidogrel group was significantly lower than that in the aspirin group (P < 0.05). Conclusions PMA are a sensitive biomarker to platelet activation in patients with cerebral infarction. In addition, although both aspirin and clopidogrel lowered the level of PMA, clopidogrel is a more effective treatment than aspirin in inhibiting platelet activation.