The Role of Circulating Platelets Microparticles and Platelet Parameters in Acute Ischemic Stroke Patients

Abstract

Background Platelet activation and aggregation are critical in the pathogenesis of acute ischemic stroke (AIS). Circulating platelet microparticles (PMPs) and platelet parameters are biological markers of platelet function in AIS patients, however, their associations with stroke subtypes and infarct volume remain unknown. Methods We recruited 112 AIS patients including large artery atherosclerosis (LAA) and small artery occlusion (SAO) subtypes, and 35 controls in this study. Blood samples were collected at admission and after antiplatelet therapy. The levels of circulating PMPs and platelet parameters [mean platelet volume (MPV), platelet count (PC), plateletocrit (PCT) and platelet distribution width (PDW)] were determined by flow cytometry and hematology analysis, respectively. Infarct volume was examined at admission by magnetic resonance imaging. Results (1) The levels of circulating PMPs and MPV were significantly elevated in AIS patients when compared with healthy controls; (2) The level of circulating PMPs, but not platelet parameters, was decreased after antiplatelet therapy in AIS patients; (3) The infarct volume in LAA subtype was larger than that in SAO subtype. Notably, circulating PMP level was positively correlated with the infarct volume in LAA subtype. No association with infarct volume in either AIS subtype was observed for platelet parameters; (4) According to the regression analysis, circulating PMPs was an independent risk factor for the infarct volume in pooled AIS patients after adjustments of other impact factors (hypertension and diabetes). Conclusions Our results suggest that circulating PMP level is associated with cerebral injury of AIS, which offers a novel evaluation parameter for AIS patients.

The role of inflammation markers in predicting the prognosis of Bell's palsy

“…This result might be due to the small number of unrecovered patients in this study. MPV and PDW markers have been representing the platelet activation [14][15][16]. The MPV value shows the size of platelets while the PDWvalue is used to evaluate variations in platelet size.…”

Possible roles of platelet-derived microparticles in atherosclerosis

“…PMPs participate in a variety of physiological functions, mainly including promotion of blood clotting, endothelial repair, angiogenesis, intercellular signal transduction, and inflammatory responses [8,14,16]. PMPs exist in the blood of normal healthy individuals and different sizes of PMPs have different functions in platelets and ECs [10], and influence many disease processes, including malignant tumor formation, hemolytic disorders, such as thrombotic thrombocytopenic purpura and sickle cell disease, conditional cardiovascular diseases, such as coronary artery disease and stroke, inflammatory diseases, including pregnancy, abortion, and preeclampsia, and the formation of phlebothrombosis [13], atherosclerosis, idiopathic thrombocytopenia purpura, cancer, and rheumatoid arthritis [13].…”

“…Besides, Atherosclerosis is characterized by an increased concentration of CD41 þ and CD61 þ ECs [18]. Meanwhile, it has been demonstrated that PMPs can stimulate aggregation of leukocytes in vitro and express tissue factor (TF) and other cytokines through the pselectin glycoprotein ligand-1 receptor [16]. p-selectin, which is known to promote atherosclerosis via inducing leukocyte recruitment to ECs, is a glycoprotein existing in the membrane of platelet and endothelial cells, also expressed in the membranes of PMPs [23].…”

“…Besides, PMPs can also lead to bleeding, as in Scott syndrome, because of the loss of platelet coagulation due to defective PS. Patients with Scott syndrome have lower PMP concentrations and this deficiency in PMPs can lead to the formation of blood coagulation disorders [16].…”

Investigating the effect of age on platelet ultrastructure using transmission electron microscopy

“…Most of the previous studies conducted on age‐related changes in platelets were conducted on adults of 25–65 years . Furthermore, numerous studies have demonstrated that many diseases, including diabetes, cardiovascular disease, and different physiological states, have an effect on platelet ultrastructure …”