The influence of citrate concentration on the quality of plasma obtained by automated plasmapheresis: a prospective study

BACKGROUND: There is a need for more comprehensive work dealing with the qu ality of plasma collected by automated plasmapheresis using different final concentrations of citrate anticoagulant. A prospective study was performed to examine the influence of three concentrations of sodium citrate on the levels of clotting factors and markers of activated hemostasis and fibrinol ysis. STUDY DESIGN AND METHODS: Fifty-one experienced plasma donors were recruite d for subsequent 750-mL plasmapheresis procedures using 4-percent (wt/vol) sodium citrate. Anticoagulant-to-blood ratios of 1:16.6, 1:14.2, and 1:12.5 were used, corresponding to sodium citrate concentrations of 6 percent, 7 percent, and 8 percent (vol/vol), respectively. Between two plasmapheresis procedures, there was a washout period of 7 days. Determinations were made of the plasma levels of fibrinogen and factors V, VII, VIII, and IX, as wel l as antithrombin, tissue-type plasminogen activator, and several markers o f activated hemostasis and fibrinolysis: activated factor VII, prothrombin splits products, D-dimers, and beta-thromboglobulin. RESULTS: The plasma samples anticoagulated with 6-percent citrate contained significantly higher levels of factors V, VIII, and IX than the samples an ticoagulated with 8-percent citrate (p<0.0001, p less than or equal to 0.00 01 and p = 0.009, respectively). The citrate concentration had no influence on the levels of fibrinogen, factor VII, antithrombin, or tissue-type plas minogen activator. There was no evidence that the plasma samples containing lower citrate concentrations were more prone to activation of hemostasis o r fibrinolysis. CONCLUSION: A reduction in the final citrate concentration of plasma collec ted by automated plasmapheresis results in higher yields of factors V, VIII , and IX without activation of hemostasis. More comprehensive studies shoul d confirm previous work dealing with the establishment of the lowest citrat e concentration acceptable in plasma used as therapeutic fresh-frozen plasm a or as starting material for the manufacture of plasma derivatives.