Diagnostic utility of flow cytometry based coated‐platelets assay as a biomarker to predict thrombotic or hemorrhagic phenotype in acute stroke

Abstract

Background Coated‐platelets are sub‐population of platelets “coated” with highly procoagulant proteins and phosphatidylserine that sustains thrombin generation. They are produced upon dual agonist stimulation by collagen and thrombin. This study was conducted to assess if there was any difference in the levels of coated‐platelets in patients with primary intracranial hemorrhage (PICH) and ischemic stroke due to large artery atherosclerosis (LAA) as compared to healthy controls, and to see if coated‐platelet levels had any influence on the hemorrhagic transformation (HT) of ischemic stroke. Methods Coated‐platelet levels were determined by flow cytometry using fluorescently tagged Annexin V antibody to identify phosphatidylserine exposed on the surface of platelets activated by dual agonists (convulxin and thrombin) in cross‐sectional cohort of 75 patients with stroke and 34 controls. Results Patients with PICH (n = 35) had significantly lower coated‐platelets than the controls (adjusted mean ± SE, 21.0 ± 1.9% vs. 36.1 ± 1.7%, p < 0.001), while patients with LAA (n = 30) had significantly higher coated‐platelets than controls (adjusted mean ± SE, 51.9 ± 1.5% vs. 36.1 ± 1.7%, p < 0.001). Patients with subsequent HT of ischemic stroke (n = 10) had significantly lower coated‐platelet levels at admission compared to those without HT (adjusted mean ± SE, 18.1 ± 2.6% vs. 51.9 ± 1.5%, p < 0.001). Conclusions Coated‐platelet levels are significantly different in patients with hemorrhagic and ischemic stroke as compared with controls. Lower levels of coated‐platelets measured by flow cytometry may be earliest predictor of subsequent HT in patients with ischemic stroke even before the radiological changes suggestive of HT are visualized.

Feasibility and comparability of different platelet function tests in acute stroke with or without prior antiplatelet therapy

“…In previous studies, FACS of specific coated platelets, which exhibit procoagulant proteins and phosphatidylserine, has been investigated as a tool to differentiate between hemorrhagic and thrombotic stroke with notable results, highlighting the potential of this method ( 29 ). Interestingly, in a study of patients with acute ischemic stroke a weaker response of CD62p expression on platelets to stimulation with thrombin was observed compared to healthy individuals, which was attributed to cleavage of the protease-activated receptor-1 ( 30 ).…”

The Link between Stroke Risk and Orodental Status—A Comprehensive Review

“…Imaging investigations and physical examinations are frequently used to diagnose strokes. Studies on the prevention of stroke have begun to consider biomarkers, and several biomarkers have been identified [ 37 ]. Among them, it is commonly accepted that inflammatory biomarkers are associated with a higher risk of stroke etiology and outcome [ 38 ].…”

Issue Highlights—September 2022

“…Here Awirut Charoensappakit et al describes a novel flow cytometric approach looking at the relationship between surface phosphatidylserine expression on RBCs and RBC derived micro particles. The authors use sizing beads to define large micro particles in urine samples with CD235a and annexing V and to define RBCs and their expression of phosphatidylserine (Dave et al, 2022; Sutherland et al, 2020). They demonstrate increased numbers of RBC derived micro particles and surface phosphatidylserine expressing RBCs in patients with glomerular hemolysis versus patients with non‐glomerular hemolysis.…”