Procoagulant impact of the plasmapheresis procedure on coagulation state of collected plasma.

Plasmapheresis is a group of extracorporeal techniques that involve removal of whole blood, separation of plasma from cellular elements and partial return of blood components (at least the red blood cells) into the circulation. It is widely used for therapy and plasma collection with the purpose of either further transfusion or manufacture of medicines. Plasmapheresis necessarily involves significant contact of blood with inner surfaces of the plasmapheresis kit, so the possibility of contact activation of coagulation is a concern with regards to both donor safety and quality of the product obtained. Although initial1 (and some recent2) studies did not detect any noteworthy coagulation changes in donors’ blood, this view was challenged by other reports. Using a more sensitive global assay of thromboelastography, hypercoagulation was found following various apheresis procedures3. Some researchers found that there could be additional pro-coagulant mechanisms for donors who often undergo apheresis4, while others did not detect any differences in intensive donors5. Dangerous or even fatal venous and arterial thromboses were reported in individual cases after large-volume donations, usually when donors had pre-disposing risk factors6,7. Nevertheless, existing screening processes that plasma donors undergo do not take into account blood coagulation. There is even less information about the effect of plasmapheresis on the coagulation status of the collected plasma. Although the composition of such plasma with regard to coagulation factors and activation markers has been evaluated by some researchers8–10, we are not aware of any attempts to systematically compare the coagulation system in collected plasma with that of the original donor plasma. Here we carried out such a comparison using three global assays of the coagulation system: thrombin generation, thromboelastography and thrombodynamics together with clotting assays and other methods. Global assays that are increasingly used these days aim to mimic coagulation in vivo better11 and are particularly noteworthy for their ability to detect pro-coagulant changes, unlike traditional clotting assays12–15. Using these assays we found significant changes in coagulation occurred as a result of the plasmapheresis procedure.