Neutrophil function is preserved in a pooled granulocyte component prepared from whole blood donations

Whole blood-derived granulocytes (buffy coats) are issued as an alternative to apheresis donations, but are heavily contaminated with red cells and platelets and there is minimal in vitro data describing their functionality. We developed a purer pooled granulocyte component (PGC) from whole blood donations by pooling 10 ABO-matched buffy coats with 400 ml of platelet additive solution (SSP+) and re-centrifuging. The PGC was irradiated (25-50 Gy) and neutrophil viability, chemotaxis, phagocytosis and respiratory burst activity were determined by flow cytometry. Results from 13 PGC at 16-20 h following donation were compared with those obtained from 20 standard individual buffy coats and with fresh whole blood. The PGC contained similar numbers of neutrophils (approximately 0.9 x 10(10)) with a reduced volume and haemoglobin content when compared with 10 individual buffy coats. Neutrophils in the PGC maintained >90% viability, oxidative burst and phagocytic activity and their ability to migrate towards a chemoattractant 16-20 h following donation, which is similar to results obtained with either fresh whole blood or standard buffy coats. Therefore, neutrophil function in the PGC was preserved 16-20 h following donation, but this product had significantly lower red cell contamination compared with 10 buffy coats, which are currently transfused.