Thromb Haemost 1993; 70(06): 0951-0958
DOI: 10.1055/s-0038-1649706
Original Article
Coagulation
Schattauer GmbH Stuttgart

Interaction of Immobilised Unfractionated and LMW Heparins with Proteins in Whole Human Plasma

Adrian Zammit
1   The Heart Research Institute, Sydney, Australia
,
Duncan S Pepper
2   The National Science Laboratory, Scottish National Blood Transfusion Service, Edinburgh, Scotland
,
Joan Dawes
1   The Heart Research Institute, Sydney, Australia
› Author Affiliations
Further Information

Publication History

Received 17 February 1993

Accepted after revision 12 July 1993

Publication Date:
06 July 2018 (online)

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Summary

The profile of proteins bound to immobilised heparins in hirudin-anticoagulated human plasma was analysed. In molar terms, antithrombin III was the most abundant protein bound to therapeutic doses of unfractionated heparin (Mr = 12,000), whereas heparin cofactor II constituted <1% of the protein bound. Histidine-rich glycoprotein was the only plasma protein likely to influence anticoagulant activity by direct competition with antithrombin III, though significant quantities of complement Factor H, fibrinogen, fibronectin, vitronectin and apolipo-protein B were also detected. Only traces of von Willebrand factor, complement factor I, inter-α-trypsin inhibitor, a2-macro-globulin, serum amyloid P and transferrin were identified, and neither thrombospondin nor platelet factor 4 were measurable. Binding of both antithrombin III and histidine-rich glycoprotein varied with the ratio of heparin to plasma. Clexane (Mr = 4,500) also bound anti thrombin III, but both histidine-rich glycoprotein and vitronectin were quantitatively significant neutralising proteins. Neutralising proteins dominated the binding profile for Oligo H (Mr = 2,200).