Bioenergetic profiling of cold stored and room temperature stored platelets as an indicator of platelet viability and function

George, Chloë Elizabeth (2025) Bioenergetic profiling of cold stored and room temperature stored platelets as an indicator of platelet viability and function. Doctoral thesis (DClinSci), Manchester Metropolitan University.

Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (3MB)

Abstract

Interest in the use of cold stored platelets (CSP) has experienced a resurgence due to changes in clinical practice, driven by a reduction in platelet transfusion for prophylactic reasons and an increase in their use for the treatment of acute bleeding in traumatic haemorrhage resuscitation and surgery, both within hospital and pre-hospital care. CSP demonstrate many benefits over room temperature stored platelets (RTP) including longer shelf life, decreased bacterial risk and easier logistics for transport, as well as making platelet concentrates (PC) accessible in areas where they have not previously been, such as in the pre-hospital environment. CSP are reported in vitro to have superior haemostatic functions, forming stronger, firmer clots. However, clinical trial data on their use is limited and discussion around the maximum potential shelf life continues. In this study, the in-vitro activation and haemostatic function of RTP and CSP were compared, and novel bioenergetic assays were performed to create metabolic profiles of RTP and CSP during prolonged storage. RTP and CSP were compared for up to 21 days of storage in terms of their morphology, activation state, ability to aggregate and their metabolic function, including glucose production, lactate production and ATP levels. Bioenergetic profiles were deduced by examining the mitochondrial membrane potential and by direct measurement of the oxygen consumption rate and extracellular acidification rate, with the aim of determining an appropriate maximum shelf life for CSP. This work demonstrates that CSP are ‘primed’ for use, with higher levels of activation markers and improved functional responses (aggregation response to ADP & collagen and the ability to produce more thrombin and faster) compared to RTP. Bioenergetic profiles showed a move from mitochondrial respiration towards a more glycolytic phenotype by the end of storage for both RTP and CSP, indicating that mitochondria become damaged during prolonged storage. The mitochondrial membrane potential was markedly decreased in CSP by day 21 along with very low glucose levels suggesting that CSP may not be a viable product by 21 days of storage. The findings indicate that the bioenergetic profile perhaps does not accurately reflect platelet function in CSP. Further, the work has highlighted the extensive potential benefits of CSP for bleeding patients and for the logistics of blood supply chains and has provided some compelling data to help justify initiation of clinical trials involving the use of CSP in the UK.