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Published on: August 13, 2015
Endothelial and platelet microparticles in vasculitis of the young
P A Brogan1, V Shah, C Brachet
1Department of Nephrourology, Institute of Child Health, London, UK. BrogaP@gosh.nhs.uk
Insights
Endothelial microparticles (EMPs) were significantly elevated in children with active systemic vasculitis, indicating potential for noninvasive assessment of vascular injury. These findings suggest EMPs offer insights into endothelial activation in pediatric vasculitis.
Area of Science:
- Pediatric Rheumatology
- Vascular Biology
- Biomarker Discovery
Background:
- Endothelial microparticles (EMPs) are released during endothelial dysfunction and disease.
- Elevated EMPs are observed in various conditions linked to endothelial dysfunction.
- Systemic vasculitis in children involves endothelial injury and activation.
Purpose of the Study:
- To investigate endothelial microparticle (EMP) and platelet microparticle (PMP) profiles in children with systemic vasculitis.
- To test the hypothesis that EMPs can serve as a noninvasive marker of endothelial activation or injury in pediatric vasculitis.
- To compare microparticle levels in active vasculitis, remission, febrile disease, and healthy controls.
Main Methods:
- Plasma samples from 39 children with systemic vasculitis, 24 febrile disease controls, and 43 healthy controls were analyzed.
- Microparticles were isolated via ultracentrifugation.
- Flow cytometry was used to quantify EMPs (E-selectin+, CD105+) and PMPs (CD42a+, P-selectin+).
Main Results:
- Significantly higher E-selectin-positive EMPs and CD105-positive EMPs were found in active vasculitis compared to remission, healthy, and febrile controls.
- Increased PMPs expressing CD42a were observed in active vasculitis.
- EMP counts correlated with vasculitis activity scores and acute-phase reactants in patients.
Conclusions:
- Endothelial microparticles (EMPs) may serve as a valuable indicator of endothelial activation in pediatric systemic vasculitis.
- EMPs offer potential pathophysiologic insights into vascular injury in young patients with vasculitis.
- Further research into EMPs could lead to noninvasive diagnostic or monitoring tools for childhood vasculitis.
Objective:
Microparticles are released from endothelial cells in response to a variety of injurious stimuli and recently have been shown to be increased in a number of diseases associated with endothelial dysfunction. This study examined endothelial microparticle (EMP) and platelet microparticle (PMP) profiles in children with systemic vasculitis to test the hypothesis that EMPs may provide a noninvasive means of examining endothelial activation or injury.
Methods:
The study cohort comprised 39 children with systemic vasculitis at various stages of disease activity, 24 control children with febrile disease, and a control group of 43 healthy subjects. Plasma was ultracentrifuged at 17,000g for 60 minutes, and the microparticle pellets were examined using flow cytometry.
Results:
Plasma from patients with active systemic vasculitis contained significantly higher numbers of E-selectin-positive EMPs compared with that from patients in remission, healthy controls, or febrile disease controls (P = 0.000 for each). A similar result was obtained for the numbers of EMPs expressing the marker CD105. There was also a significant increase in PMPs expressing CD42a in the active vasculitis group as compared with the other groups, but this difference was not significant for PMPs expressing P-selectin. The EMP counts correlated with the Birmingham Vasculitis Activity Score and the acute-phase reactant levels in the patients with systemic vasculitis, but there was a poor correlation overall between EMP counts and the acute-phase reactant levels in the febrile disease controls.
Conclusion:
EMPs may provide a window to the activated endothelium and could provide important pathophysiologic insights into the vascular injury associated with vasculitis of the young.
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