Lozano M L, Rivera J, Corral J, Gonzalez-Conejero R, Vicente V
Unit of Hematology, Hemotherapy and Clinical Oncology, School of Medicine, Centro Regional de Hemodonación, Murcia, 30003, Spain.
Cryobiology. 1999 Aug;39(1):1-12. doi: 10.1006/cryo.1999.2184.
Cryopreservation of platelets is of great interest since it could extend to years the shelf life of therapeutic platelet concentrates (PCs) and facilitate stockpiling and inventory control in blood banking. We have compared the cryopreservation of PCs by the standard method using 6% Me(2)SO as cryoprotectant with the method of freezing employing low concentrations of Me(2)SO (2%) plus ThromboSol, a mixture of second-messenger effectors that protect platelets from cold damage. PC pools were treated either with 6% Me(2)SO or with ThromboSol and 2% Me(2)SO and then placed directly in a -80 degrees C freezer or in the vapor phase of a liquid nitrogen freezer (-120 degrees C). After storage for 1 week or for 3 months, samples were removed, thawed, and analyzed. Measurements included cell recovery, biochemical parameters, membrane glycoproteins (GPs), platelet aggregation, and binding of radiolabeled von Willebrand factor (vWF) and fibrinogen. PCs cryopreserved with ThromboSol and 2% Me(2)SO displayed a platelet recovery (90%) equivalent to those frozen with 6% Me(2)SO. Following either cryopreservation procedure, platelets showed increased surface expression of P-selectin and moderate loss of GP Ibalpha in comparison to fresh platelets. The aggregatory response to ristocetin and the binding of vWF were similar in platelets frozen by either procedure. Finally, both methods promoted comparable impairment of the reactivity of platelets to thrombin, aggregation and binding of fibrinogen and vWF, compared to that of fresh platelets. In summary, cryopreservation of PCs using reduced Me(2)SO concentration and ThromboSol yields platelets with in vitro functional characteristics equivalent to those of cells frozen with the conventional method using 6% Me(2)SO.
血小板的冷冻保存备受关注,因为它可以将治疗性血小板浓缩物(PCs)的保质期延长至数年,并有助于血库中的储存和库存控制。我们将使用6%二甲基亚砜(Me(2)SO)作为冷冻保护剂的标准冷冻保存PCs方法与采用低浓度Me(2)SO(2%)加血栓溶解剂(ThromboSol,一种保护血小板免受冷损伤的第二信使效应物混合物)的冷冻方法进行了比较。PC库分别用6% Me(2)SO或血栓溶解剂加2% Me(2)SO处理,然后直接放入-80℃冰箱或液氮冰箱的气相中(-120℃)。储存1周或3个月后,取出样本,解冻并进行分析。测量指标包括细胞回收率、生化参数、膜糖蛋白(GPs)、血小板聚集以及放射性标记的血管性血友病因子(vWF)和纤维蛋白原的结合。用血栓溶解剂和2% Me(2)SO冷冻保存的PCs显示出与用6% Me(2)SO冷冻的PCs相当的血小板回收率(90%)。与新鲜血小板相比,两种冷冻保存方法处理后的血小板均显示P-选择素的表面表达增加,且糖蛋白Ibalpha中度丢失。两种方法冷冻的血小板对瑞斯托菌素(ristocetin)的聚集反应以及vWF的结合相似。最后,与新鲜血小板相比,两种方法均导致血小板对凝血酶的反应性、纤维蛋白原和vWF的聚集及结合能力出现相当程度的损害。总之,使用降低浓度的Me(2)SO和血栓溶解剂冷冻保存PCs所获得的血小板,其体外功能特性与使用6% Me(2)SO的传统方法冷冻的细胞相当。