Assessment of the soluble proteins HMGB1, CD40L and CD62P during various platelet preparation processes and the storage of platelet concentrates: The BEST collaborative study.

BACKGROUND: Structural and biochemical changes in stored platelets are influenced by collection and processing methods. This international study investigates the effects of platelet (PLT) processing and storage conditions on HMGB1, sCD40L, and sCD62P protein levels in platelet concentrate supernatants (PCs). STUDY DESIGN/METHODS: PC supernatants (n = 3748) were collected by each international centre using identical centrifugation methods (n = 9) and tested centrally using the ELISA/Luminex platform. Apheresis versus the buffy coat (BC-PC) method, plasma storage versus PAS and RT storage versus cold (4°C) were investigated. We focused on PC preparation collecting samples during early (RT: day 1-3; cold: day 1-5) and late (RT: day 4-7; cold: day 7-10) storage time points. RESULTS: HMGB1, sCD40L, and sCD62P concentrations were similar during early storage periods, regardless of storage solution (BC-PC plasma and BC-PC PAS-E) or temperature. During storage and without PAS, sCD40L and CD62P in BC-PC supernatants increased significantly (+33% and +41%, respectively) depending on storage temperature (22 vs. 4°C). However, without PAS-E, levels decreased significantly (-31% and -20%, respectively), depending on storage temperature (22 vs. 4°C). Contrastingly, the processing method appeared to have greater impact on HMGB1 release versus storage duration. These data highlight increases in these parameters during storage and differences between preparation methods and storage temperatures. CONCLUSIONS: The HMGB1 release mechanism/intracellular pathways appear to differ from sCD62P and sCD40L. The extent to which these differences affect patient outcomes, particularly post-transfusion platelet increment and adverse events, warrants further investigation in clinical trials with various therapeutic indications.

Label-free on chip quality assessment of cellular blood products using real-time deformability cytometry.

Without cellular blood products such as platelet concentrates (PC), red blood cell concentrates (RCC), and hematopoietic stem cells (HPSC) modern treatments in medicine would not be possible. An unresolved challenge is the assessment of their quality with minimal cell manipulation. Minor changes in production, storage conditions, or blood bag composition may impact cell function, which can have important consequences on product integrity. This is especially relevant for personalized medicine, such as autologous T-cell therapy. Today a robust methodology that globally determines cell status directly before transfusion or transplantation is lacking. We demonstrate that measuring viscoelastic characteristics of peripheral blood cells using real-time deformability cytometry (RT-DC) provides comprehensive information on product quality, which is not accessible using conventional quality control tests. In addition, RT-DC requires few cells, a minimal sample volume and has a rapid turnaround time. We compared RT-DC to standard in vitro quality assays assessing: i) PC after storage at 4 °C and room temperature; ii) magnetic nanoparticle labeled platelets; iii) RCC stored in blood bags with different plasticizers; iv) RCC after gamma irradiation; and v) HPSC after cryopreservation with 5% or 10% dimethyl sulfoxide, respectively. Additionally, we evaluated the engraftment time of patients' platelets and leukocytes after transplantation of HPSC products. Our results demonstrate that label-free mechano-phenotyping can be used as a potential biomarker for quality assessment of cell-based pharmaceutical products.