Platelet Function, Activation and Apoptosis During and After Apheresis

Abstract

Platelets are known to undergo shape change, activation, release reaction and apoptosis/necrosis during processing and storage. Apheresis may have a deleterious impact on platelet achievability and functional integrity. Platelet concentrates from 50 male volunteers obtained by COBE spectra were screened for platelet activation (CD62 and CD154) and apoptosis (phosphatidylserine detected by Annexin V). Donor samples before separation, during apheresis and at the third day of storage were used as baseline donor samples. Platelet aggregation to adenosine diphosphate (ADP) and collagen was performed. There was a statistically significant increase in the expression of activation markers in two different samples (during separation samples and third day samples). Although the increase in Annexin V expression was not so observable, it showed a significant increase also. There was marked decline in the platelet aggregation. The correlations between the values of CD62, CD154 and Annexin V were detected in baseline samples and increased during separation and at the third day of platelets storage. Correlation between values of platelet aggregation to collagen and Annexin V was relevant only in the baseline samples. No other correlations were encountered between platelet aggregation and markers of activation and apoptosis during apheresis and storage. Initial platelet activation induced by apheresis may have an impact on phosphatidylserine expression with no impact on aggregation function of platelets during storage.

CD40 ligand (CD154) involvement in platelet transfusion reactions

“…In a study of 50 male platelet concentrates screened for platelet activation, Bakry et al found a positive correlation between CD40L and Annexin V on the surface of platelets that increased during separation of platelets from whole blood and again when tracked on the third day of storage (29). A more detailed kinetic investigation of the spontaneous release of sCD40L from multiple donor pooled platelet concentrates demonstrated an increase through 72 hours and remained at those levels through 126 hours.…”

Effect of 3-Day Storage and Temperature on ADP-induced Platelet Aggregation

“…17 Platelets only have 45% activity towards ADP activation on day 1, and gradually decrease to 12% on day 5. 10 Similarly, another study reported that platelet aggregation response towards ADP and collagen activation decrease gradually from day 1 to day 5, from 78% to 17%. 16 Contrary to those reports, this study observed that platelets have no measurable response to ADP-induced aggregation on day 3, whilst, from earlier reports, the activity was still measurable until day 5.…”

“…8 Many researchers have argued that storing platelets in 4 °C will prevent bacterial growth and will lower the platelet metabolic rate, although it is still controversial if cold storage gives more benefit in preserving platelet responsiveness to agonist activation. 8,10,11 In this study, the platelet functions during 3 days of platelet storage was evaluated using the platelet aggregation test despite the fact that the light transmission aggregatory (LTA) is widely used as a gold standard for platelet function test. 12 Platelet aggregation evaluation is considered as the easiest and the most economical method for the purposes of platelet abnormality screening, diagnosis, monitoring therapy, predicting bleeding, and assessing stored platelet.…”

Only the Truth Would Enlighten Us — The Advantages and Disadvantages of Flow Cytometry as a Method of Choice in the Study of Mouse and Rat Platelets

“…Thus, the protocol may appear to drive artifactual outcomes, as far as it perpetuates platelet activation, although, paradoxically, it has been designed to determine the extent of platelets' readiness to get activated. Remarkably, all the above hallmarks, presented in the course of platelets' staining with annexin V, are strictly convergent with those typical for apoptosis [215][216][217][218]. Then, it is of no wonder that merely the determination of annexin V binding might discriminate reliably apoptotic from nonapoptotic platelets.…”