Membrane Glycoproteins in Cryopreserved Platelets

Abstract

Although platelets stored by cryopreservation are effective in hemostasis, they acquire a number of functional defects during storage and preparation for transfusion. In addition to known acquired defects such as defective aggregation, decreased resistance to hypotonic shock, and disc-spherocyte transformation, we have shown that cryopreserved platelets have decreased capacity to adhere to subendothelium, compared to liquid-stored platelets. To investigate this decrease in adhesive capacity of cryopreserved platelets, we measured the major adhesive membrane glycoprotein, GPIb, and the principal aggregatory protein, GPIIb/II- Ia, using flow cytometry in fresh platelets or in platelets cryopreserved in 5% DMSO. We also analyzed aggregation of cryopreserved platelets or liquid-stored platelets in response to ristocetin as another measurement of GPIb functional capacity. We found that approximately 15% of cryopreserved platelets lost surface-bound GPIb, while there was no measurable loss of GPIIB/IIIa during cryopreservation. The cryopreserved platelets also showed a significant decrease in aggregation to ristocetin, but no loss of response to the stronger agonist, thrombin. The loss of surface GPIb from cryopreserved platelets was modest in degree, approximately that reported for liquid-stored platelets, and does not seem great enough to account for the observed functional changes in aggregation and adhesion.

The use of cryopreserved platelets in the treatment of polytraumatic patients and patients with massive bleeding

“…Although these functional defects are not clinically significant and CPs effectively treat bleeding, one must be cognizant of these changes. [22][23][24] In the group of patients transfused with FAPs, a significantly higher platelet count was found in the peripheral blood when compared to the patients transfused with CPs. An increase in the concentration of platelets in the blood count after transfusion might be hard to observe following the transfusion of CPs.…”

“…CPs exhibit significantly decreased ristocetin‐induced platelet aggregation but do not lose the ability to respond to more potent thrombin‐receptor agonists. Although these functional defects are not clinically significant and CPs effectively treat bleeding, one must be cognizant of these changes …”

Cryopreservation of Platelets: Advances and Current Practice

“…This cryoprotectans, previously rarely used, are no longer used for cryopreservation of blood [20][21][22][23][24].…”

“…cryopreserved platelets also showed a significant decrease in aggregation to ristocetin, but no loss of response to the stronger agonist, thrombin. Even though these defects are of a minor clinical relevance and the cryopreserved platelets were shown to be safe and Cryopreservation Biotechnology in Biomedical and Biological Sciences effective for the treatment of abnormal bleeding, it is still necessary to reckon with these changes [22,40,41].…”