Platelet-Derived Procoagulant Microvesicles Are Elevated in Patients with Retinal Vein Occlusion (RVO)

Abstract

The etiopathogenesis of retinal vein occlusion (RVO) is multifactorial, and the contribution of platelets to RVO development has not been fully elucidated. We aimed to analyze platelet function in RVO patients (n = 35) and controls (n = 35). We found a higher (p < 0.05) level of soluble P-selectin in RVO group vs. controls. Additionally, in RVO patients, the concentration of platelet-derived microvesicles was higher (p < 0.05), and the difference between groups was deeper for the fraction of platelet-derived microvesicles with the procoagulant phenotype (p < 0.0001) and for overall procoagulant microvesicles level (p < 0.0001). The results were similar for the total RVO group and for both RVO types (central- and branched-retinal vein occlusion). We did not find differences in simple platelet parameters (platelet count, mean platelet volume, platelet distribution width, platecrit, reticulated platelets) and inflammatory markers (platelet-lymphocyte ratio, neutrophil-lymphocyte ratio). Similarly, no differences were found for platelet aggregation-stimulated byadenosine diphosphate; collagen; arachidonic acid; and in multiparametric flow cytometry evaluation of P-selectin, PAC-1, and fibrinogen binding for both unstimulated and adenosine diphosphate-, collagen-, and thrombin receptor activating peptide-stimulated platelets. Our results suggest that platelets can contribute to developing RVO by enhancing procoagulant activity through providing a procoagulation surface via platelet-derived microvesicles. The direct role of platelets’ hyperreactivity in developing RVO is less apparent, which is consistent with the complexity and multifactorial background of this disorder.

Factors influencing ranibizumab efficacy and prognosis of patients with retinal vein occlusion and macular edema based on systemic inflammatory indexes and OCT parameters

“…RVO is linked with atherosclerotic cardiovascular risk factors. Prior research has highlighted heightened expression of platelet-derived microvesicles and NETs-related markers in RVO patients, indicating functional activation of platelets and neutrophils [9]. RVO is influenced by the interplay of platelets, coagulation response, endothelial cells, and inflammatory response amidst blood flow abnormalities [10].…”

Assessment of systemic inflammatory response index and other inflammatory indicators in retinal vein occlusion

“…[ 31 ] A recent study showed that although platelet count, MPV, PDW, plateletcrit, reticulated platelets, and platelet-lymphocyte ratio were similar to the control group in patients with RVO, the level of soluble P-selectin and concentration of platelet-derived procoagulant microvesicles was higher in patients with RVO in both BRVO and CRVO. [ 32 ] P-selectin is one of the best markers of platelet activation. Microvesicles are derived from membrane blebs of activated platelets and have pro-coagulant, anti-coagulant, pro-inflammatory, and angiogenic properties.…”

Comparative analysis of the quality of platelet concentrates produced by apheresis procedures, platelet rich plasma, and buffy coat

“…12 PMPs are derived from activated platelets and are the most abundant fraction of MPs in blood. 13 Recent evidence suggests that PMPs in blood circulation are associated with inflammation 14 and hypercoagulation, 15 thus being of pathophysiological importance in many diseases. 15,16 Siljander and colleagues reported that PMPs are associated with fibril formation.…”

“…Microparticles (MPs) in blood circulation are a heterogeneous population of small vesicles with an approximate 0.1–1.0 μm diameter, which can be generated by red blood cells, endothelial cells, white blood cells, and platelets 12 . PMPs are derived from activated platelets and are the most abundant fraction of MPs in blood 13 . Recent evidence suggests that PMPs in blood circulation are associated with inflammation 14 and hypercoagulation, 15 thus being of pathophysiological importance in many diseases 15,16 .…”