DIFFERENT EFFECTS OF 2 METHODS OF LOW-DENSITY-LIPOPROTEIN APHERESIS ON THE COAGULATION AND FIBRINOLYTIC SYSTEMS

Objective. Immunoadsorption (IMA) and dextran sulfate adsorption (DSA) are two methods for selective extracorporeal elimination of low-densi ty lipoproteins which are known as LDL apheresis. Their influence on h aemostasis until now is widely unknown. Design. The effects of both LD L apheresis procedures on the coagulation and fibrinolytic systems wer e compared amongst five patients treated with IMA and four patients wh o received a DSA therapy. Subjects. All patients with severe heterozyg ous familial hypercholesterolaemia were participants in a long-term LD L apheresis programme with treatments every 1-2 weeks. Intervention. C ombined anticoagulation with heparin and citrate in IMA, and also hepa rin exclusively in DSA were used for the extracorporeal circulation. M easures. Blood samples were taken immediately before and after a singl e LDL apheresis and five times during the weekly interval until the ne xt therapy. Results. DSA had a significantly greater effect on standar d clotting tests than IMA at the end of plasma therapy despite identic al dosages of heparin. DSA caused a considerable reduction of the coag ulation factors V, VIII:C, vWF:Ag, XI, XII, and prekallikrein by 48-99 % at the end of apheresis treatment whereas only factor VIII:C showed a marked decrease of 72% after IMA. All abnormalities of the global co agulation tests and of most clotting factors were restored 1 day after treatment in both procedures followed by a moderate rebound phenomeno n of single coagulation factors during the next few days in IMA-treate d patients. Conclusion. DSA exerts a more profound effect on the coagu lation system than IMA by a substantial coelimination of various clott ing factors in addition to the desired removal of atherogenic lipoprot eins.