Determination of plasma dermatan sulfate at relevant pharmacological concentrations.

1. Routine clotting assays and tests used for monitoring heparin therapy are not suitable for measuring plasma DS in most clinical conditions. 2. Sensitive and specific assays have been developed recently for this purpose. They are based on different biological properties of DS. 3. As DS is heterogeneous, significant differences between the results obtained with different assays are expected. 4. Ex vivo measurements of DS do not reflect an actual concentration because, due to complex pharmacokinetics, the spectrum of molecular species found in a patient's plasma may be different from that present in the material administered. 5. DSs from different sources may exhibit wide variations in structure and biological properties. Ex vivo assays must be calibrated with the DS preparation administered to the patient. Information obtained with one DS is not reliable for other DSs. 6. The relationship between ex vivo activities of DS and antithrombotic effects in man is unknown. Simultaneous assessment of DS concentration and of activation of coagulation in models such as hemodialysis will be very welcome.