Granulocyte bactericidal capacity and chemotaxis as affected by continuous-flow centrifugation and filtration leukapheresis, steroid administration, and storage

While granulocyte transfusions have been shown to be effective in the treatment of patients with infections, the effects of the leukapheresis collection procedure on certain granulocyte functions remain in question. We studied the bactericidal function of granulocytes collected by continuous-flow centrifugation (CFC) and filtration leukapheresis (FL) with 5. aureus, E. coli, and S. typhimurium. Killing of all organisms was normal with CFC and FL cells if the medium in which the cells were suspended was buffered. Low pH suspension medium had an adverse effect on bactericidal function. Chemotaxis of FL cells was slightly but not significantly reduced. Adrenocorticosteroids are frequently administered to white blood cell donors in order to increase the yield of collected cells. Granulocytes collected by routine venipuncture from subjects who had taken a single dose of prednisone or dexamethasone had normal bactericidal function. Prednisone administration appeared to increase migration of granulocytes in vitro. Evaluation of function of FL granulocytes stored at 4°C showed significant decrease in bactericidal function at 72-96 hr with a more rapid and significant decrease in chemotactic function at 24 hr. These studies provide guidelines for methods of collection and storage of granulocytes that will preserve optimal cell function.