Platelet cryopreservation using a combination of epinephrine and dimethyl sulfoxide as cryoprotectants

Current methods of platelet storage are unsatisfactory because of the short shelf life of platelets and the rapid loss of platelet viability. We have developed a cryopreservation method that results in less damage from freezing and higher recovered function of platelets. Platelets were cryopreserved using a combination of epinephrine (EPN) and dimethyl sulfoxide (Me(2)SO) as cryoprotectants. The response of platelets to agonists was studied by flow cytometry and aggregation tests. Cryopreserving platelets with Me(2)SO decreased platelet annexin V binding due to freezing. The combination of EPN with Me(2)SO enhanced Me(2)SO cryoprotection and decreased platelet microparticle generation, suggesting that cryopreserving platelets using this combination is associated with increased platelet integrity. Platelet cryopreservation with an Me(2)SO/EPN combination also increased platelet aggregability, which was demonstrated by decreasing the lag phase and increasing the aggregation density to 66.39% +/- 6.6 that of fresh platelet-rich plasmas. We conclude that adding EPN as a combined cryoprotectant improves the quality of Me(2)SO-frozen platelets. As a method of aggregation of cryopreserved platelets, this method is comparable to that of normal fresh platelets and may improve the conditions for platelet transfusion.