U.S. Army Institute of Surgical Research San Antonio, Texas, United States
Background/Case Studies: Hemorrhage remains a leading cause of mortality in clinical settings and the leading cause of preventable death on the battlefield, necessitating effective blood component utilization. Cryopreserved platelets have proven more effective than room temperature liquid stored platelets at reducing blood loss in cardiopulmonary bypass patients and offer prolonged shelf life. However, access to cryopreserved platelets continues to inhibit efficient use. Vitrafy Life Sciences Limited has designed and developed an innovative solution for cryopreserving living cells, increasing survival and functionality compared to industry standards while alleviating supply issues. In this work, we sought to evaluate quality, viability, and function in cryopreserved platelets processed with a Vitrafy cryopreservation system.
Study
Design/Methods: Apheresis platelet units (n=8) were cryopreserved at -80°C with BloodStor 27 Freeze Media (BS27), trehalose (TREH), or neat (NEAT) using a Vitrafy VCU1 Device. Postthaw samples were obtained for each arm, along with a prefreeze baseline sample. Platelet quality was evaluated using complete blood count, blood gas analysis, and visual inspection. Hemostatic function was assessed using thromboelastography and thrombin generation capacity. Platelet phenotype was determined using flow cytometry.
Results/Findings: Cryopreservation resulted in a platelet recovery rate >89% for all groups (Fig. 1A). All postthaw samples resulted in pH >7.0. BS27 PT samples preserved clot strength (maximum amplitude, MA; Fig. 2B better than TREH (p=0.001) and NEAT (p< 0.0001). Thrombin generation lagtime was significantly shortened in all PT samples compared to PF (Fig.2C). While peak thrombin generation levels of PT samples were 2.5-fold higher than prefreeze, all exhibited comparable endogenous thrombin potential. PLT swirl was present in BS27 and TREH but not NEAT. Platelet constitutive markers were preserved and activation was increased after cryopreservation.
Conclusions: BS27 and TREH cryopreserved platelets are more procoagulant than prefreeze. BS27-cryopreserved platelets preserve hemostatic function better than TREH. Understanding the interplay between cryopreservation techniques and PLT functionality may lead to improved transfusion protocols and more lives saved.
