Platelet Storage: Time to Rethink the Cold

Cherise Farrugia

Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Malta.

Byron Baron

Centre for Molecular Medicine and Biobanking, University of Malta, Malta.

Vanessa Zammit *

Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Malta and Centre for Molecular Medicine and Biobanking, University of Malta, Malta and National Blood Transfusion Services, Malta.

*Author to whom correspondence should be addressed.


Platelet concentrates (PCs) are widely used in transfusion medicine for therapeutic purposes and their demand is constantly on the rise. Current storage regulations make this product highly susceptible to bacterial contaminations and platelet storage lesions (PSL) causing the need for alternative storage methods to be considered. The implementation of cold storage not only reduces unnecessary wastage of valuable donations and overall costs but also decreases both the risk of bacterial contamination and the occurrence of PSL. The current study aimed at determining how a prolonged cold storage may affect PCs. This was accomplished by investigating two different PC cohorts of 10 units each. One of the cohorts, labelled as ‘Room Temperature’, was stored at 22℃±2℃ for 5 days and then transferred to a temperature of 4℃±2℃. The other cohort, labelled as ‘Cold’, was stored directly at 4℃±2℃. Both cohorts were stored for a total of 21 days and platelet indices, platelet counts, pH, and platelet factor IV (PF4) were measured at different time intervals. Sterility was performed on Day 21. The key findings showed no significant difference in mean platelet count, platelet distribution width (PDW), mean platelet volume (MPV), platelet-large cell ratio (P-LCR), and plateletcrit (PCT) between the two cohorts. On the other hand, a significant difference in mean pH and PF4 resulted between the two cohorts. Moreover, no significant difference in mean platelet count, and PCT was found between Days 1, 5, or 10, and Day 21 in both cohorts. However, an overall significant difference in mean PDW, MPV, P-LCR and pH was discovered between Days 1 and 21, Days 5 and 21, and Days 10 and 21 in both cohorts. Regards PF4, a significant difference was detected between Days 1 and 21, and Days 10 and 21; however, no significant difference was found between Days 5 and 21 in both cohorts. Corynebacterium freneyi and Microbacterium liquefaciens, were cultured from 1 unit of the room temperature cohort after it was flagged positive during the sterility testing. In conclusion, through the implementation of a delayed cold storage system, PCs can be safely administered to the patient.

Keywords: Platelet concentrates, cold storage, prolonged shelf-life, quality, safety

How to Cite

Farrugia , C., Baron , B., & Zammit , V. (2023). Platelet Storage: Time to Rethink the Cold. International Blood Research & Reviews, 14(4), 57–69.


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