Polymorphonuclear Leukocytes Prepared by Continuous-Flow Filtration Leukapheresis: Viability and Function

Preparation of granulocytes for transfusion in high yield and relatively free of contamination by other cell types has been made possible by the technique of continuous-flow filtration leukapheresis (CFFL). Since previous work suggested that granulocytes collected in this manner may have impaired viability and function, a detailed study of the bactericidal, metabolic, and chemotactic properties of such cells was performed and compared to control cells obtained from the same donors prior to CFFL. The granulocyte percentage of the cell suspensions obtained by CFFL averaged 94.5% ± 1.5% compared to 82.5% ± 1.8% for the controls (p < 0.001) with viability of the PMNs determined by trypan blue exclusion being 97.5% ± 0.9% and 98.2% ± 0.5%, respectively. The phogocytic, metabolic (¹⁴C-I-glucose oxidation and protein iodination) and chemotactic properties of both cell types were equivalent in suspensions equalized for granulocyte content. These findings indicate that CFFL technique employed does not impair granulocyte viability or function in vitro. Studies of the in vivo survival and function of CFFL granulocytes are necessary to evaluate their efficacy in combating infection in severely leukopenic patients.