Effects of the addition of second-messenger effectors to platelet concentrates separated from whole-blood donations and stored at 4 degrees C or -80 degrees C

BACKGROUND: Platelet concentrates (PCs) are currently stored at 22 degrees C under continuous agitation. Because of the potential risk of the overgrow th of bacteria in case of contamination, PC shelf life is limited to 5 days . A mixture of second-messenger effecters is being evaluated to determine i f it has benefits for cold liquid storage and cryopreservation of platelets . STUDY DESIGN AND METHODS: PCs separated from whole-blood donations by the b uffy coat method were randomly assigned (n = 6 each) to be stored for 5 day s at 22 degrees C under continuous agitation or at 4 degrees C after treatm ent with a platelet storage medium (ThromboSol, LifeCell Corp.). PCs were a lso cryopreserved with 6-percent DMSO (final concentration) or with Thrombo Sol plus 2-percent DMSO (final concentration) (TC). After storage, platelet s were analyzed by flow cytometry, transmission electron microscopy, and ag gregation and perfusion techniques. RESULTS: Cold liquid storage of ThromboSol-treated platelets resulted in a lower binding of coagulation factor Va on the platelet surface than on plat elets stored at 22 degrees C. In transmission electron microscopy, a conver sion to spherical morphology was seen in the case of cold liquid storage. N o difference between ThromboSol-treated platelets stored at 4 degrees C and platelets stored at 22 degrees C was seen in perfusion studies. Cryopreser vation in the presence of TC prevented the reduction in glycoprotein Ib and IV expression on platelet surface that is seen in 2-percent DMSO-cryoprese rved platelets. Platelets cryopreserved in TC covered, by thrombus, a signi ficantly greater percentage of the perfused surface after the freezing and thawing process. CONCLUSION:ThromboSol-treated PCs separated from whole-blood donations by t he buffy coat method, stored at 4"C for 5 days, or cryopreserved in the pre sence of TC, maintained in vitro functional activity comparable to that ach ieved by current methods of storage, although discoid morphology was not pr eserved during cold liquid storage with ThromboSol.