Comparison of the Non-Specific Binding of Unfractionated Heparin and Low Molecular Weight Heparin (Enoxaparin) to Plasma Proteins

The non-specific binding of anticoagulantly-active heparin to plasma proteins may influence its anticoagulant effect. We used low affinity heparin (LAH) essentially devoid of anti-factor Xa activity to investigate the extent and possible mechanism of this non-specific binding. The addition of excess LAH to platelet-poor plasma containing a fixed amount of unfractionated heparin doubled the anti-factor Xa activity presumably because it displaces …