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Updated: May 25, 2026

Methods for Quantitative Detection of Antibody-induced Complement Activation on Red Blood Cells
Published on: January 29, 2014
Complement C3 is a novel plasma clot component with anti-fibrinolytic properties
Joanna-Marie Howes1, Victoria R Richardson, Kerrie A Smith
1Division of Cardiovascular & Diabetes Research, Leeds Institute of Genetics Health & Therapeutics, University of Leeds, UK.
Background And Method:
Increased plasma clot density and prolonged lysis times are associated with cardiovascular disease. In this study, we employed a functional proteomics approach to identify novel clot components which may influence clot phenotypes.
Results:
Analysis of perfused, solubilised plasma clots identified inflammatory proteins, including complement C3, as novel clot components. Analysis of paired plasma and serum samples confirmed concentration-dependent incorporation of C3 into clots. Surface plasmon resonance indicated high-affinity binding interactions between C3 and fibrinogen and fibrin. Turbidimetric clotting and lysis assays indicated C3 impaired fibrinolysis in a concentration-dependent manner, both in vitro and ex vivo.
Conclusion:
These data indicate functional interactions between complement C3 and fibrin leading to prolonged fibrinolysis. These interactions are physiologically relevant in the context of protection following injury and suggest a mechanistic link between increased plasma C3 concentration and acute cardiovascular thrombotic events.
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