Enhanced circulatory parameters of human platelets cryopreserved with second-messenger effectors: an in vivo study of 16 volunteer platelet donors

Platelet transfusion represents an important component of the therapy for t hrombocytopenic patients. Prolonged storage capabilities for platelets woul d alleviate many problems associated with blood banking. Unfortunately curr ent cryopreservation methods are complex to implement and result in loss of cell number and functional activity Previous in vitro studies have shown t hat the use of ThromboSol(TM), a platelet-stabilizing formulation, in the c ryopreservation of platelets results in significant retention of cell numbe r and in vitro functional activities in addition to reducing the DMSO requi rement to only 2%. We evaluated the in vivo circulatory parameters of plate lets cryopreserved with ThromboSol, Single donor platelet units were obtain ed from healthy volunteers (n = 16); the units were then split and cryopres erved with either ThromboSol and 2% DMSO or 6% DMSO alone, Following storag e at -80 degrees C for 7-10 d the samples were thawed, washed and radiolabe lled with either Cr-51 or In-111. The paired samples were then mixed and re infused into the autologous volunteer. At various time intervals following transfusion a blood sample was drawn and the quantity of circulating labell ed platelets was determined. The percent recovery and survival time was det ermined by multiple-hit analysis. The ThromboSol-treated platelets, as comp ared to the 6% DMSO-treated platelets, displayed statistically higher perce nt recovery (40.2% v 28.8%) and survival time (166.3 h v 152.1 h). These re sults demonstrated that platelets cryopreserved with ThromboSol displayed s uperior ill vitro and in vivo characteristics as compared to the standard 6 % DMSO method. The use of ThromboSol allowed for a 3-fold reduction in the DMSO concentration in conjunction with a 40% increase in circulating cell n umber and normal survival times.