The Missing Pieces to the Cold-Stored Platelet Puzzle

Abstract

Cold-stored platelets are making a comeback. They were abandoned in the late 1960s in favor of room-temperature stored platelets due to the need for longer post-transfusion platelet recoverability and survivability in patients with chronic thrombocytopenia. However, the current needs for platelet transfusions are rapidly changing. Today, more platelets are given to patients who are actively bleeding, such as ones receiving cardiac surgeries. It has been established that cold-stored platelets are more hemostatically effective, have reduced bacterial growth, and have longer potential shelf lives. These compelling characteristics led to the recent interest in bringing back cold-stored platelets to the blood systems. However, before reinstating cold-stored platelets in the clinics again, a thorough investigation of in vitro storage characteristics and in vivo transfusion effects is required. This review aims to provide an update on the recent research efforts into the storage characteristics and functions of cold-stored platelets using modern investigative tools. We will also discuss efforts made to improve cold-stored platelets to be a better and safer product. Finally, we will finish off with discussing the relevance of in vitro data to in vivo transfusion results and provide insights and directions for future investigations of cold-stored platelets.

In vitro comparison of cold‐stored whole blood and reconstituted whole blood

“…Indeed, in line with previous studies [9,10,16,18], both ADP-and TRAP-induced platelet aggregation in CSWB decreased already during 14-day storage. As platelets in CSWB are exposed to cold storage, this impaired aggregation is seemingly in contradiction with increased platelet activation and enhanced haemostatic capacity of cold-stored platelet concentrates [19,20], but in accordance with the finding of attenuated aggregation responses to ADP and TRAP in CSWB as compared to cold-stored platelet concentrates [10]. This implies that other CSWB components, namely, RBCs and plasma, may influence platelet functionality.…”

Analysis of Transfusion-Transmitted Bacterial Infections according to German Hemovigilance Data (2011–2020)

“…Similarly, lyophilized and cold-stored platelets could be an alternative for treatment of increased platelet consumption in acute hemorrhage. However, their safety and effectiveness in humans have still to be proven [ 35 , 36 , 37 , 38 ].…”

Quantitative increases of extracellular vesicles in prolonged cold storage of platelets increases the potential to enhance fibrin clot formation

“…PLT aggregation within PCs was not significantly increased in CS (Figure 5), as previously published data suggested. 8 Johnson et al 14 ; Reddoch et al 48 and others, summarised in a review by Zhao et al, 49 have reported that PLT aggregation in CS appears to be dependent on the PAS used, therefore comparisons across studies must be interpreted with caution. The biggest reported improvement when comparing aggregation between RT and CS platelets is related to ADP 8 ; however, ADP was not used in this study due to our observation that ADP was not able to induce aggregation from day 3 onwards (data not shown), as has been reported by others.…”