Platelet quality after 15‐day storage of platelet concentrates prepared from buffy coats and stored in a glucose‐free crystalloid medium

It has been reported previously that platelet concentrates (PCs) prepared from buffy coat pools diluted in a simple, glucose‐free medium (BC‐PCs) are effective in thrombocytopenic patients after 4 to 12 days of storage. Such preparations produce platelet increments similar to those of traditional PCs prepared from platelet‐rich plasma (PRP‐PCs) stored for 1 to 3 days. The purpose of this study was to obtain a series of in vitro measurements during storage to allow a more detailed characterization of BC‐PCs and a more detailed comparison of BC‐PCs with PRP‐PCs. At the beginning of storage, the level of (alpha granule membrane protein‐140 (GMP‐140), a marker of platelet activation, was significantly higher on PRP‐PC platelets, and BC‐PCs were superior in measurements reflecting platelet function, such as osmotic reversal, ATP release, and aggregation with collagen. Compared to PRP‐PCs, BC‐PCs were superior in the percentage of discs, total ATP, and glycoprotein lb expression by Day 7. This superiority became more striking on Day 11. Overall, 15‐day‐old BC‐PCs compared favorably to 7‐day old PRP‐PCs: BC‐PCs were superior in ATP release and aggregation with collagen, but they were not significantly different for all other measurements reflecting platelet quality and function. Thus, the quality of platelets in BC‐PCs was superior on Day 1, and this superiority progressed as storage continued. In addition, the metabolism of BC‐PCs was favorable. During 15 days of storage, pH and bicarbonate concentration did not change significantly In BC‐PCs; moreover, oxygen consumption was higher and glucose utilization and lactate accumulation were markedly slower than in PRP‐PCs. The results of additional experiments performed with pooled PRP‐PCs diluted In the glucose‐free medium and stored In the same fashion as BCPCs were Intermediate between those of experiments with BCPCs and PRP‐PCs, which suggests that the superior quality of BC‐PCs Is due In part to the buffy coat method of pre aration and In part to one or more components of the storage method. This approach to platelet procurement and storage has the disadvantage of a lower platelet yield. However, it can be concluded that it produces platelets of higher quality, contaminated with fewer white cells and less plasma and with better potential for storage than is possible with PRP‐PCs.