Dr Keith McCrae speaks to ecancer about a study exploring the role of the complement–platelet axis in thrombosis associated with antiphospholipid syndrome (APS) presented at ASH 2025.

The research shows that platelets from APS patients display a procoagulant phenotype, with increased phosphatidylserine exposure and P-selectin expression, closely linked to complement deposition on the platelet surface.

Dr McCrae explains that APS patient serum induces this procoagulant activity through IgG-mediated complement activation, involving both the classical and alternative pathways and culminating in C5b-9 deposition.

He reports that complement-bound procoagulant platelets strongly correlate with thrombotic events in APS and may serve as more effective biomarkers of thrombotic risk than conventional antibody profiling.