Examining the non-haemostatic function of alternatively stored platelets
- Publication Type:
- Thesis
- Issue Date:
- 2023
Open Access
Copyright Clearance Process
- Recently Added
- In Progress
- Open Access
This item is open access.
Currently, platelet components are stored at room-temperature, limiting the shelf life to 5-7 days due to the risk of bacterial proliferation and a gradual reduction in haemostatic function. The short shelf-life makes maintaining platelet supplies to remote medical centres impractical. Further, between 10 20% of platelet products are discarded due to expiry. Consequently, there has been renewed interest in the evaluation of alternative storage methodologies including platelet refrigeration and platelet cryopreservation. Both techniques allow for the potential extension of shelf-life while better preserving the haemostatic function of platelets compared to room temperature storage. Recent findings have identified that both refrigeration and cryopreservation alter the abundance of receptors on the surface membrane and soluble factors released into the supernatant. Additionally, storage induced changes in immune phenotype have been linked to adverse events post-transfusion in room-temperature stored components. In general, very little is known about the effects of refrigeration and cryopreservation on the immune characteristics of platelets. As such, the overall aim of this thesis was to address these knowledge gaps to further aid the clinical evaluation of refrigerated and cryopreserved platelets.
Receptors on the platelet surface membrane facilitate pathogen recognition, leukocyte interaction and leukocyte activation. Platelet activation can mobilise receptors from internal stores to the surface membrane. This can influence the ability of platelets to adhere to pathogens and leukocytes. Platelet-pathogen recognition is linked to direct pathogen killing, clearance and also immune evasion. In contrast, platelet-leukocyte interaction can lead to the formation of platelet-leukocyte aggregates which mediate anti-pathogenic activity, platelet clearance, leukocyte differentiation and pro-inflammatory function. In this dissertation, the effect of refrigeration and cryopreservation on the abundance of immune receptors on the platelet surface membrane was examined. This information provides insight into how alternatively stored platelets may interact with pathogens and other immune cells.
Platelet activation induced by storage or immunological stimuli can cause degranulation, releasing a range of soluble factors into the surroundings, facilitating pathogen clearance, cellular proliferation, leukocyte migration and inflammation. Notably, the accumulation of pro-inflammatory soluble factors in the supernatant of platelet components has been directly linked with an increased risk of adverse events post-transfusion. The research presented in this thesis characterises the concentration of pro-inflammatory mediators in the platelet supernatant which may provide insight into the likelihood of adverse transfusion events.
Consequently, this dissertation aims provide a greater understanding of how alternative platelet storage methodologies affect the immune characteristics and function of platelets in vitro.
Please use this identifier to cite or link to this item: