Measurement of platelet p-selectin expression by flow cytometry in patients with acute ischemic stroke

Evaluation of platelets activity and reactivity as risk factors for acute ischemic non-embolic stroke in young adults

Background

Ischemic stroke (IS) constitutes a relevant health concern recently in younger population causing permanent cognitive and function-limiting disability and ranks as the 3rd cause of death in Egypt after cardiac and hepatic diseases. Platelet activation has a crucial mechanism in arterial thrombogenesis, thus in pathophysiology of IS. Surface expression of P-selectin (CD62P) reflects platelet activation and measured by flowcytometry. The purpose of the study is to evaluate whether platelet activity and reactivity are considered risk factors for IS so more restrict antiplatelet protocols could be implemented for management and recurrence prevention.

Results

Study population was 60 IS patients and 60 apparently healthy age and gender-matched controls. Patients were subdivided into 37 patients without classical risk factors, aged 46.1 ± 8.2, and 23 patients with > 1 vascular risk factors, aged 52 ± 9.9. The percentage of platelets expressing CD62P reflecting ex vivo baseline activity was significantly higher in stroke patients to controls (p = 0.001), also platelet reactivity (CD62P expression after ADP provocation) was statistically significantly elevated in patients than in controls (p < 0.0001) and was significantly higher in IS patients with vascular risk factors compared to patients without risk factors (p = 0.02).

Conclusion

Both baseline platelet activity and reactivity were significantly higher in IS patients, and were also higher in IS patients with other vascular risk factors than in cryptogenic stroke and considered risk factors for IS.

Detection of Subclinical Paroxysmal Atrial Fibrillation and Its Correlation with Candidate Genes in Patients with Cryptogenic Ischemic Stroke and TIA

Introduction: Cardioembolic etiology is assumed to be the most frequent cause of cryptogenic strokes. The detection of subclinical paroxysmal atrial fibrillation (AF) is important in the correct choice of preventive treatment. The aim of this prospective study was to detect the incidence of AF in patients with a cryptogenic stroke or transient ischemic attack (TIA) and to evaluate the association between the presence of AF and selected single-nucleotide polymorphisms (SNP).

Methods: Patients with a cryptogenic stroke/ TIA (n=100) and a control group (n=15) of volunteers without significant cardiovascular disease were included in the study during the period of 2014 to 2019. To detect AF they underwent 12 months of ECG monitoring using an implanted loop recorder (ILR). Genotyping for SNPs rs10033464, rs2200733, rs225132, and rs2106261 was performed by a high resolution melting analysis.

Results: We found AF to be present in 24 (24%) patients with a cryptogenic stroke/TIA, versus no subjects in the control group. The SNPs rs2106261, rs2200733, rs225132, and rs10033464 were not found to be associated with AF in our study (p=0.240; 1.000; 0.887; 0.589). However, a weak trend for a higher frequency of rs2106261 risk allele A homozygotes was observed in the patients with AF compared to the patients without AF (0.416 vs. 0.263, p=0.073). Homozygotes for allele A of rs2106261 were also present in a significantly higher frequency in AF patients compared to the controls (0.416 vs. 0.133, p = 0.012).

Conclusion: In our study paroxysmal AF was a probable etiological factor in 24% of patients with cryptogenic ischemic stroke / TIA during the 12 months of monitoring. The homozygous allele A of rs2106261 was identified to be the possible genetic risk factor of AF, but this should be verified in larger cohorts.

The study has been registered at www.clinicaltrials.gov, identifier NCT02216370.