Quality control in neutrophil granulocyte (PMN) concentrates by flow cytometry.
BACKGROUND
In peripheral blood, chemotaxis, phagocytosis, and oxidative burst of polymorphonuclear cells (PMNs) can be assessed by flow cytometry, whereas function tests, i.e., quality control in PMN concentrates designed for neutropenia therapy, are lacking.


METHODS
PMN concentrates (n=6) harvested from healthy donors who had been premedicated with granulocyte colony-stimulating factor (G-CSF) and dexamethasone were stored undiluted (control, C; n=6) and diluted 1:4 (D; n=6) with autologous plasma for 72 h. Commercial flow cytometry function tests were performed to quantify changes in chemotaxis, phagocytosis, and oxidative burst of PMNs over time.


RESULTS
Median levels of phagocytosis and oxidative burst levelled at 86% (82-94) and 98% (83-100) in C on the day of apheresis, respectively, but deteriorated to 15% (0-24) and 0% within 72 h; in D these parameters remained close to 90%. Median levels of chemotaxis were comparable in C (69%, 65-74) and D (74%, 70-84) at baseline. No migration was detected in C after 72 h; however, D retained approximately 63% (13-76) migration capacity.


CONCLUSIONS
Quality control in PMN concentrates is practical using flow cytometry and commercial test kits. While phagocytosis and oxidative burst may be maintained for 72 h in vitro, chemotaxis of apheresed PMNs is already reduced on the day of apheresis.
Schwanke
Uwe
U
German Red Cross Transfusion Service West, Institute for Transfusion Medicine Breitscheid, Department of Research & Development, Ratingen, Germany.
Schrader
Laura
L
Moog
Rainer
R
D002634:Chemotaxis, Leukocyte; D005434:Flow Cytometry / Q000592:standards*; D005858:Germany; D006801:Humans; D066298:In Vitro Techniques; D007937:Leukapheresis; D009504:Neutrophils / Q000502:physiology*; D010587:Phagocytosis; D011786:Quality Control; D016897:Respiratory Burst