Blood Transfusion Platelet Concentrates: Preparation, Safety Standards And Principles For Better Tolerance Andavoidance Of Adverse Effects

Platelet Components (PCs)-like other Labile Blood Components (LBCs)-originate from donations by healthy, generous volunteers. The regulation in force impose strict criteria for donation acceptance, preparation of whole blood derived buffycoat PCs or single donor apheresis platelets, qualification and quality control, the storage, and also technical specifications that define the characteristics of the product for therapeutic use. Thus, indications relative to all preparation steps and use of intermediate products must read in clear on the LBC label. Despite considerable efforts for homogenization, there are still many variability factors in the products, which relate to specificities within the genetics and metabolic status of the donors. Moreover, there are different processes of preparation with different devices, as well as variability within the age of the LBCs; the latter issue is particularly sensitive with cellular products such as PCs comprise of living cells and this may influence the final quality of the PC. Finally, recipients (the transfused patients) present with their causal pathology but also display a wide range of genetic characteristics as well. There is thus a transfusion triad for variables in transfusion, perhaps exacerbated regarding PC transfusion: from the donor, the product, and the recipient. Some adverse events (AEs) can occur after PC transfusions. This review aims at presenting the different methods of PC preparation and to highlight the steps leading to cell (platelet) alterations as well key issues. The methods of preparation and storage of PC are very sensitive factors for the occurrence of AE because, in addition to the active substances, there are many active biologic derivatives triggered by the processes or amplified during the storage. A particular focus on inflammatory aspects of AEs, which mostly related to the physiology of platelets themselves will overviewed. We will also introduce the issue that platelets are prone to activation signals-some being sterile and some being driven by pathogen moieties-leading to the release to secreted products, of which a large array of pro-inflammatory factors.