Blood collection technique and processing impact the nucleosomes and complement contents of platelet products

Abstract Background and Objectives Platelet concentrates (PCs) available for transfusion are prepared either from whole blood donations or by platelet aphaeresis procedures. These different preparation methods may potentially affect damage‐associated molecular patterns (DAMPs) and complement activation products in PC, which are associated with adverse reactions (ARs). Materials and Methods The objective of this study is to perform a comparison of platelet activation, nucleosome, mitochondrial DNA (mtDNA), haem and complement activation between differently produced leukoreduced PC. Single donor aphaeresis‐PC stored in either plasma or platelet additive solution (PAS)‐E and pooled buffy‐coat (BC)‐PC stored in PAS‐E were produced in a regional setting of the Dutch Blood Establishment. For BC‐PC, a pool of five BC‐independent donors was used, and BC‐PCs were grouped based on the time of donation (morning vs. afternoon). Directly after production, samples were collected from PC, and CD62P+ platelets, nucleosomes, mtDNA, haem and complement activation products were measured. A comparison was made between aphaeresis‐PC and BC‐PC. Results Higher levels of CD62P+ platelets were observed after stimulation in aphaeresis‐PC than BC‐PC. The levels of nucleosomes and C4b/c were significantly increased in BC‐PC compared to aphaeresis‐PC. In addition, the levels of elastase‐α1‐antitrypsin complexes (EA) were higher in BC‐PC from morning blood collections than in aphaeresis‐PC or BC‐PC from afternoon blood collections, which indicates increased neutrophil activation. Conclusion Aphaeresis‐PC can be better activated than BC‐PC. BC‐PC contains higher levels of nucleosomes and EA, most likely due to the presence of neutrophils in the BC. In addition, higher levels of complement activation products were observed in BC‐PC.