Summary
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.
Keywords
C-reactive protein - Coagulation - Heparin - Serum amyloid P component - Thromboelastograph