PLATELET COLLECTION BY APHERESIS WITH RED UCED USE OF CITRATE - QUANTITATIVE AND QUALITATIVE EVALUATION OF 3 PROTOCOLS

Three protocols of platelet collection by apheresis on Cobe Spectra wi th different citrate concentrations were compared. First we determined until what level we could diminish the ratio anticoagulant/whole bloo d flow to enhance the efficiency without clotting in the cell separato r by platelet aggregates. We found that protocol 2 had a better platel et collection efficiency than the standard protocol 1 : respectively 5 9 % versus 52 %. Protocol 3 had even a better efficiency but, due to t he risk of clotting (5 % of the procedures) we rejected it for routine use. We compared in vitro platelet fonctions of protocols I and 2 by aggregometry in vitro. The results with the different aggregating agen ts indicated that the less citrated environment kept the platelets mor e fonctional in vitro. A disadvantage of protocol 2 compared to the st andard protocol is the more important number of platelet concentrates that contain more than 10(6) leucocytes.