Refrigerated platelets stored in whole blood up to 5 days adhere to thrombi formed during hemorrhagic hypotension in rats

Abstract

Essentials • In vivo function of platelets stored at various conditions was studied in normo-and hypotension. • Refrigerated platelets stored up to 5 days performed as well as those stored at room temperature. • Platelet adhesion and thrombus formation were higher in ruptured vessels of hemorrhaged animals. • In vivo data suggest that refrigerated platelets are hemo-statically effective during hypotension. Summary. Background: There is renewed interest in the therapeutic use of cold-stored platelets for bleeding patients. However, critical information is absent or partially available in vitro. Therefore, thrombus formation and platelet adhesion were studied in vivo, in situ, using bleeding and thrombosis models in instrumented rats, and confocal intravital videomicroscopy. Objectives We tested the hypothesis that refrigerated (4 °C) platelets (stored for 24 h or 5 days) participated in thrombus formation as well as platelets stored at room temperature (RT, 22 °C). This hypothesis was tested in normovolemia and hemorrhagic hypotension. Methods & Results: After fluorescently-labeled platelet infusion, endothelial injury and vessel rupture were laser-induced in cremaster microvessels and platelet adhesion in > 230 developing thrombi was evaluated. Blood samples were collected for biochemistry and coagulation assays while multiple sys-temic physiologic parameters were recorded. Hemorrhagic hypotension study animals were subjected to 40% hemorrhage , leading to hypotension and hemodilution, during in vivo platelet adhesion assessments. The fluorescence intensity associated with labeled platelet adherence provided a quantitative index of adhesion. Cold-stored plate-lets performed as well as those stored at RT in normovolemic animals. During hypotension, cold-stored platelets still performed as well as RT-stored platelets, whereas platelet adhesion and thrombus formation were increased relative to normovolemic animals, in bleeding model experiments. Conclusions: We found the methodology suitable for evaluating platelet function in vivo after different storage conditions in fully monitored animals. Refrigerated platelets (stored up to 5 days) participated as well as RT-stored platelets in thrombi formed after hemorrhage, suggesting that refrigerated platelets are effective during hypotensive situations.

In vitro quality and platelet function of cold and delayed cold storage of apheresis platelet concentrates in platelet additive solution for 21 days

“…Viscoelastic properties as measured by TEG was present in the CSP group for the entire 21‐day storage period, with better MA than room temperature storage on Day 7. This superior clot strength has previously been documented by several studies . While the DCSP group did show some remaining function on Day 21, this was substantially worse than for the CSP group.…”

Platelets derived from fresh and cold‐stored whole blood participate in clot formation in rats with acute traumatic coagulopathy

“…If bleeding time is around the range of 2–3 min, it suggests that the residual platelets that survived the initial clearance had sufficient time to participate in clot formation when active bleeding occurred, which was supported by immunohistochemistry that showed GFP + ‐platelets at the clot of the liver incision site under both conditions of sham and ATC. This is consistent with the recent paper showing that platelets derived from cold stored whole blood participate in clot formation at sites of microvascular injury by laser puncture observed by intra‐vital microscopy with actual quantification (Torres Filho et al , ).…”

Platelet enhancement of bacterial growth during room temperature storage: mitigation through refrigeration

“…10 As a result, PLTs may be transfused before contamination is ultimately detected. 10 Recently, our laboratory has demonstrated that cold storage (CS; 4-6 C) of PLTs prolongs shelf life for periods in excess of 14 days 12 and preserves both PLT viability and hemostatic function, [12][13][14][15][16][17][18] allowing adequate time to quarantine units for the requisite 7 days necessary for bacterial culture. However, a longstanding criticism of PLT CS is that while it is assumed that CS would prevent bacterial growth, to our knowledge, no specific evidence has been reported for PLT components prepared by current procedures.…”