Flow cytometric assessment of platelet function in patients with peripheral arterial occlusive disease

Abstract

This study compared new and traditional measures of platelet function in 16 patients with severe peripheral arterial occlusive disease and 15 age-matched controls. Circulating platelets were characterized by the use of fluorescence flow cytometry to assess platelet aggregate formation and expression of the secretion-dependent alpha granule membrane protein GMP-140, by measurement of plasma β-thromboglobulin (β-TG), and by performance of platelet-rich plasma aggregation studies. In addition, blood samples were treated with graded concentrations of adenosine diphosphate (ADP; 0 to 10 μmol/L) to characterize by fluorescence flow cytometry the secretory and aggregatory responses to mild stimulation. No differences were detected between the two groups with regard to platelet function in unstimulated circulating blood by use of these techniques. Values (mean ± SEM) observed were: GMP-140-positive platelets, 11% ± 3% versus 13% ± 2%; platelet aggregates in circulating whole blood, 4% ± 1% versus 9% ± 3%; plasma β-TG, 92 ± 12 versus 94 ± 22 ng/ml; and ED50 (concentration of ADP required to produce half maximal aggregation), 3.8 ± 1.1 versus 3.1 ± 0.5 μmol/L in the patients with peripheral arterial occlusive disease and controls, respectively. Treatment with ADP caused a dose-related increase in GMP-140 expression in both groups, without significant differences in this parameter between the groups at any given concentration. However, stimulation with ADP concentrations greater than 1 μmol/L resulted in more frequent aggregate formation in the control than in the peripheral arterial occlusive disease group (25% ± 4% versus 11% ± 2%, respectively at 5.0 μmol/L, p = 0.002). Further application of flow cytometry may improve our understanding of platelet function in arterial occlusive disease. (J VASC SURG 1991;14:747-56.) © 1991, Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter. All rights reserved.