[Effect of long-term plasmapheresis on blood composition. II. Changes in the concentration of coagulation factors, inhibitors, thrombocytes and its effect on routine tests of coagulation].

The influence of serial, double plasmapheresis on blood coagulation was evaluated in two groups of plasma donors submitted from three up to 306 plasmapheretic sessions. An average of 375 or 660 ml of plasma respectively were weekly harvested from the donors. No statistically significant changes were observed in platelet count, activity of factor V and factor VIII, fibrinogen, plasminogen, alpha-2-macroglobulin, antithrombin III and prothrombin time, irrespectively of the frequency and the number of plasmapheresis. The concentration of alpha-1-antitrypsin was already increased after 7 plasmapheresis in both groups of donors. KCCT was progressively shortened with the increasing volume of harvested plasma (p 0.05) and thrombin time was prolonged (p 0.05).