Short-Term Platelet Refrigeration May Reduce Inhibitory Signaling, Enhance Responsiveness

Short-term refrigeration of 1-2 hours may be sufficient to reduce inhibitory signaling and enhance platelet responsiveness, a team of German investigators reported last month in Scientific Reports.

Researchers from the Institute of Clinical Transfusion Medicine and Haemotherapy at the University of Wuerzburg in Germany led the study, which compared the effect of short-term cold temperature (2–6 degrees Celsius) and room temperature (20–24 degrees Celsius) storage on freshly prepared platelet-rich plasma (PRP). Investigators analyzed inhibitory signaling, activation markers, chemokine release, aggregation and adhesion or aggregate/thrombus formation under flow conditions. They also reviewed several characteristics of platelet integrity.

Compared to room temperature storage, 1 hour of refrigeration led to an approximate 20% decrease in basal and induced vasodilator-stimulated phosphoprotein (VASP) phosphorylation levels, determined by Western blot analysis and flow cytometry. At the same time, ADP- and collagen-induced threshold aggregation values increased by up to 30–40% during 1 hour of refrigeration. Furthermore, short-term refrigeration only led to minor spontaneous release of chemokines, the researchers found.

While this study compared outcomes in PRP, investigators believe that their findings may have implications for the storage of platelet concentrates (PC), a similar product that is frequently used to treat hemorrhage. PCs are regularly stored at room temperature, which can increase the risk of bacterial growth and the development of storage lesions.

According to the authors, 1-2 hours of refrigeration may be considered a rational approach to obtain PC with higher functional reactivity to treat hemorrhage. However, they emphasized that additional research is necessary to confirm the improved hemostatic effects by short-term refrigeration and to analyze platelets from PC, which are stored for different periods under blood banking standards and regulatory specifications.