The thrombocytopenia has multiple causes: Activation of complement Deposition of platelets on damaged endothelial surfaces Disseminated intravascular coagulation Formation of immune complexes that can associate with platelets Platelet apoptosis Removal of the platelet surface sialic acid, resulting in increased platelet clearance by the liver mediated by hepatocyte Ashwell-Morell or Kupffer cell CLEC4F receptors