Analysis of Oxidative Burst Capacity of Neutrophils in Buffy-Coat Concentrates

Buffy-Coat concentrates (BFCs) can be transfused to provide neutrophil support in patients with febrile neutropenia. In this study, the oxidative burst capacity of neutrophils in BFC was investigated in 12 hours-stored BFCs (n=16). Samples taken from healthy volunteers (n=7) (fresh EDTA; fEDTA) and taken before donation from blood donors who donated BFCs (n=16) (donor EDTA; dEDTA) were included. fEDTA and dEDTA samples were used to compare the effect of time. Nitroblue tetrazolium (NBT) test was performed to evaluate the oxidative burst. Different titrations (1:16, 1:32, 1:64, 1:128) of phorbol myristate acetate (PMA) were used. BFC samples without PMA addition were used as negative control (NC). While similar results were obtained in BFC samples with fEDTA samples in NC, oxidative activity was statistically high in the dEDTA samples. These results suggested that neutrophils in dEDTA may be spontaneously activated. In all PMA titrations except 1:64 PMA titers, the oxidative burst capacity in dEDTA and BFC samples was significantly lower than that in fEDTA samples. Also, oxidative burst significantly decreased in fEDTA-dEDTA-BFC in all PMA titrations. Spontaneous burst was detected in dEDTA samples under PMA-free conditions, but not in BFC samples, indicating that the additive solution in BFC protected neutrophils from spontaneous activation. Despite the statistically significant decrease, neutrophils in BFCs can remain functional due to their high oxidative activity at all titers (above 75%). This indicates that they can function when transfused. This result also shows that we can use BFCs as a source of neutrophils in experiments.