Bioactive lipids from stored cellular blood components: in vitro method is crucial for proper interpretation

We read with interest the recent publication of Vlaar and colleagues,1 which detailed the accumulation of bio-active lipids during the storage of blood products and their findings that these lipids are not cell but plasma and temperature dependent. In this article the authors demonstrated that lyso-PCs did not accumulate during the routine storage of prestorage leukoreduced (buffy coat removal) red blood cells (LR-RBCs) in SAGM, 42 days at 2 to 4°C, and did not evidence priming activity using a 30-minute neutrophil (PMN) priming assay in which the respiratory burst was measured in the presence of the plasma or plasma fraction of the stored component. However, if plasma was added to the LR-RBCs then there was a significant increase in lyso-PCs on Day 1 that did not increase over the storage interval. In addition, platelet (PLT) concentrates, stored in plasma, did evidence lyso-PC accumulation during routine storage, 7 days at 20 to 24°C, and the plasma fraction primed the PMN oxidase after 30 minutes. The accumulation of lyso-PCs was inhibited; however, the priming activity was not abrogated when SSP was substituted as the storage solution (65%–95%)Final. The authors concluded that the observed accumulation of lyso-PCs was time and temperature dependent and had little to do with the cellular constituents of the stored product.