Is a decrease of microparticles related to improvement of hemostasis after FVIII injection in hemophilia A patients treated on demand?

Mobarrez, Fariborz; Miković, Danijela; Antovič, Aleksandra; Antović, Jovan P.

doi:10.1111/jth.12103

Cited by 9 publications

(9 citation statements)

References 28 publications

(36 reference statements)

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“…We also observed a lower number of CD62+ MVs in patients, both in the baseline sample and after the infusion of FVIII in comparison to the controls. Our patients showed a lower amount of CD144+ microvesicles after the infusion of FVIIII, a decrease which was also observed in the study of Mobarrez et al (30). It is likely that this decrease may be related to the inclusion of these MVs in the platelet thrombus.…”

Section: Microvesiclessupporting

confidence: 88%

Platelet Function and Microvesicles Generation in Patients with Hemophilia A

Melero-Amor¹,

Romecín²,

Iyú³

et al. 2020

Preprint

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Aim: In the present work we have studied the role of platelets and microvesicles in patients with severe hemophilia A (HA) treated under the regimen of prophylaxis. We have analyzed whether the administration of coagulation factor FVIII modifies this hemorrhagic phenotype in a cohort of 16 patients with diagnosis of severe HA, who were on prophylactic treatment with recombinant FVIII. Methods: Blood tests were performed before (72h without FVIII, baseline sample) and after 15 minutes of FVIII infusion. As a control group, 15 healthy subjects were studied. Platelet aggregation was determined by closure time, optical aggregation, impedance aggregation and flow cytometry. We also studied the expression of the platelet activation markers P-selectin, CD63, platelet-tissue factor, formation of platelet-leukocyte aggregates and tissue factor exposure. The total number of platelet and endothelial microvesicles were also analyzed by flow cytometry, as well as platelet cytosolic Ca2+ mobilization. Results: We found no significant differences in platelet function in patients with severe HA in prophylactic treatment before and after FVIII infusion. After FVIII administration, patients presented fewer endothelial microvesicles, indicating that the treatment does not increase one of the possible thrombotic risk markers of these patients. The total amount of plasma microvesicles and the platelet microvesicles were decreased in patients with HA compared to the control group. Conclusions: Our results do not support any effect of FVIII on platelet function in patients with severe HA treated under the regime of prophylaxis.

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Section: Microvesiclessupporting

confidence: 88%

Platelet Function and Microvesicles Generation in Patients with Hemophilia A

Melero-Amor¹,

Romecín²,

Iyú³

et al. 2020

Preprint

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“…One study evaluated MPs by FCM in hemophilia A patients before and after receiving FVIII infusion for a documented clinical bleeding event. The authors observed a significant decrease in total MPs, PMPs and EMPs after treatment [74]. It was suggested that MP incorporation into a developing hemostatic plug at the site of injury explained their decreasing numbers after treatment.…”

Section: Phenotypic Vs Functional Assays For Microparticle Analysismentioning

confidence: 99%

Microparticle analysis in disorders of hemostasis and thrombosis

2015

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Microparticles (MPs) are submicron vesicles released from the plasma membrane of eukaryotic cells in response to activation or apoptosis. MPs are known to be involved in numerous biologic processes, including inflammation, the immune response, cancer metastasis, and angiogenesis. Their earliest recognized and most widely accepted role, however, is the ability to promote and support the process of blood coagulation. Consequently, there is ongoing interest in studying MPs in disorders of hemostasis and thrombosis. Both phosphatidylserine (PS) exposure and the presence of tissue factor (TF) in the MP membrane may account for their procoagulant properties, and elevated numbers of MPs in plasma have been reported in numerous prothrombotic conditions. To date, however, there are few data on true causality linking MPs to the genesis of thrombosis. A variety of methodologies have been employed to characterize and quantify MPs, although detection is challenging due to their submicron size. Flow cytometry (FCM) remains the most frequently utilized strategy for MP detection; however, it is associated with significant technological limitations. Additionally, pre-analytical and analytical variables can influence the detection of MPs by FCM, rendering data interpretation difficult. Lack of methodologic standardization in MP analysis by FCM confounds the issue further, although efforts are currently underway to address this limitation. Moving forward, it will be important to address these technical challenges as a scientific community if we are to better understand the role that MPs play in disorders of hemostasis and thrombosis.

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“…Notably, the detection and quantification of MVs in blood are hampered by their methods of isolation, their nanometric size, and the relatively low abundance of some specific MV subpopulations such as endothelial MVs . In this issue, Mobarrez and colleagues report on the influence of factor (F) VIII injection on MP count and activity in hemophilia A patients . The authors nicely showed that plasma MP count (except leucocyte MPs) decreased after on‐demand treatment with FVIII concentrate in hemophilia A patients and that the decrease in circulating MPs correlated with hemostatic activation.…”

Section: Proposed Guidance On the Pre‐analytical Steps For Mp Charactmentioning

confidence: 99%