Study of platelet aggregation induced by shear stress using flow cytometry / 解放军医学杂志

ABSTRACT

Objective To establish a flow cytometric method for assay of platelet aggregation induced by shear stress(SIPA) and investigate its clinical value. Methods After the whole blood was subjected to a certain shear stress by a rotational viscometer, the platelets were activated and aggregated. Then the fluorescence antibody CD61 PerCP was added to stain the platelets. The free platelets and aggregates were counted respectively by flow cytometry, thereby the ratio of platelet aggregation was calculated. Results Shear stress-induced whole blood platelet aggregation varied with the increase of shear stress and time of stress. Only a small amount of platelet aggregation was detected at relatively low shear stress of 100S -1, and it was increased at 500S -1. However, a significant increase occurred with 2 000S -1. It approached to the maximum value (58.4%?5.3%) at 3 000S -1 with exposure of 3min, which was higher than the values at 100S -1(9.4%?1.3%)and 500S -1(26.4%?3.2%). At the same time, the aggregates increased in size and became more compact with increase in the shear stress and prolongation of time. High shear stress induced platelet aggregation(H-SIPA) was significantly enhanced in patients with AMI, cerebral infarction, TIA or diabetes, all of them were susceptible to coagulopathy, compared with normal control. Conclusion The results indicated that shear stress could induce platelet aggregation directly, and the degree of SIPA had positive correlation with the stress stength and exposure time.The measurement of H-SIPA was of some clinical value in the diagnosis of arterial thrombosis.