A Study about Platelet Activation Following Plateletpheresis

Background: As single donor platelets (SDP) has been increasingly used, the quality of SDP, especially apheresis-induced platelet activation, has become a major issue. This study evaluated the activation of SDP platelets prepared with three different cell separators that are currently being used at the Korean Red Cross. Methods: CD62p, CD63 and CD42 were measured in 35 units of SDP prepared with Amicus (Baxter, Deerfield, IL, USA), MCS+ (Haemonetics, Braintree, MA, USA), or Trima (Gambro BCT, Lakewood, USA) using flow cytometry. Results : Expression of CD62p gradually increased with storage time, but no difference in expression was noted between cell separators. Expression of CD63 also increased with storage time and platelets prepared with the Amicus displayed significantly higher CD63 expression 72 and 120 hours after collection compared to those prepared with MCS+ and Trima. Expression of CD42b tended to decrease with storage time, but this was only significant for Amicus 120 hours after collection. No difference in CD42b expression was noted between cell separators. Conclusions : Platelet activation increased with storage time, and platelet activation was more pronounced in the platelets prepared with the Amicus. However, because in vitro results of platelet activation does not necessarily reflect in vivo platelet function and survival, additional studies are needed to clarify clinical effectiveness of activated platelets.