Appearance of WBC-Platelet Complex in Acute Ischemic Stroke, Predominantly in Atherothrombotic Infarction

Aim: Platelet aggregates with white blood cells (WBC-platelet complex) have recently been proposed as a marker of activated platelets, in addition to well-known molecular markers. We aimed to investigate the colocalization of activated platelets and WBC-platelet complex by means of flow cytometry, in patients with ischemic stroke. Methods: Eighty-six patients with cerebral infarction (CI) in the acute phase (58 males, 28 females; 65±14 years old) and 62 non-CI controls (23 males, 39 females; 53±14 years old) were registered. The appearance of WBC-platelet complex was quantified using 3-color flow cytometry. Results: The appearance rate of WBC-platelet complex was significantly higher in the CI group than in the controls. The appearance rate of WBC-platelet complex was significantly higher in atherothrombotic infarction (AT) than in lacunar infarction (LA) (p < 0.05). Furthermore, positive rates of both monocyte-platelet complex and granulocyte-platelet complex, but not lymphocyte-platelet complex, were significantly higher in the AT group than in the controls. Conclusion: We concluded that WBC-platelet complex, especially involving monocytes and granulocytes, is a novel marker of platelet activation in the acute phase of ischemic stroke, mainly in AT.