Further studies on the modulation of blood coagulation by human serum amyloid P component and its acute phase...

Serum amyloid P component (SAP), and its acute phase homologue C-reactive protein (CRP), prolonged activated partial thromboplastin times (APTT) in cell free plasma when assayed at physiological concentrations in the presence of heparin. SAP also inhibited clot formation initiated through the extrinsic and terminal phases of coagulation in heparinized cell free plasma, an activity not shared with CRP. When CRP and SAP were similarly evaluated in whole blood using the thromboelastograph (TEG), CRP delayed the onset of coagulation and the initial rate of fibrin formation/polymerization; final clot patency was unaltered. SAP suppressed the anticoagulant activity of heparin in the TEG assay, unlike results obtained in heparinized cell free plasma, by facilitating a more rapid onset of coagulation, increasing the rate of fibrin formation/polymerization, and correcting clot patency. The data provided offer further evidence that these homologues can intercede in blood coagulation.