title: Plateletpheresis by discontinuous centrifugation: effect of collecting methods on the in vitro function of platelets.
abstract: The in vitro function of platelets collected by two different methods during centrifugal plateletpheresis was compared. The RBC method involves collecting platelets with red cells followed by a supplementary spin to remove them, whereas the no-RBC method requires collecting platelets only from the buffy coat without red cells. Platelet response to adenosine diphosphate (ADP), epinephrine and collagen was slightly reduced in platelet-rich plasma (PRP) prepared by no-RBC technique and was markedly decreased in samples obtained by the RBC technique when compared to prepheresis controls. The decrease in platelet response to ADP, epinephrine and collagen was apparent in three testing systems: aggregation, release of serotonin and reptilase clot retraction. Both plasma and platelets appeared to be affected by the pheresis procedure. Platelet preparations obtained by both RBC and no-RBC techniques showed an increase of platelet factor 3 activity and an enhancement of aggregation, release of serotonin and clot retraction induced by thrombin as compared to prepheresis controls. Postpheresis platelet-poor plasma contains platelet membrane fragments which exhibit a high platelet factor 3 activity. The results showed that the RBC method, although providing a higher platelet yield, caused more qualitative alterations in platelets than in those obtained by no-RBC method, and that both methods of collecting platelets activated the procoagulant activity of platelets.
mesh_terms: D001792:Blood Platelets / Q000502:physiology* / Q000648:ultrastructure; D002498:Centrifugation; D006801:Humans; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D010956:Plasmapheresis / Q000379:methods*; D010974:Platelet Aggregation; D010977:Platelet Factor 3; D012701:Serotonin / Q000502:physiology
chemical_list: D012701:Serotonin; D010977:Platelet Factor 3