Liquid storage of granulocytes.

The length of time that neutrophils can be stored is the most limited of any of the formed elements of the blood that are presently transfused clinically. Several methods have been used to evaluate the storage of granulocyte concentrates. These include cell counts, cell volume, morphology, dye exclusion, oxygen consumption, hexose monophosphate shunt activity, nitroblue tetrazolium dye reduction, chemiluminescence, phagocytosis, microbial killing, adhesion, locomotion, intravascular recovery and half life. These tests indicate that the sequential loss of various neutrophil functions during storage is in the reverse order of their chronological acquisition during cellular maturation. Chemotaxis is the most sensitive indicator of neutrophil damage. In vitro tests show that neutrophils can be stored for approximately 24 hours. However, in vivo tests of chemotaxis suggest that this may be too optimistic. Whole blood, plasma and synthetic media have been evaluated for storage. Investigations of the latter are embryonic and further efforts should be encouraged. Several storage conditions have been evaluated. These studies suggest that the ideal conditions for storage area a pH of 7.2, room temperature (20-24C) and no agitation. Neither premedication of the donor with glucocorticoids nor irradiation of the granulocyte concentrate alters the storage potential of the unit. Cells collected by filtration leukapheresis should not be stored.