Factors Influencing Neutrophil Retention on Glass Bead Columns

Abstract

These studies were undertaken in an attempt to relate changes in neutrophil adhesion as measured in vitro in whole blood to neutrophil kinetic changes occurring in normal subjects in response to various stimuli. A variety of technics for measuring neutrophil adhesion in vitro were studied. The most reproducible technic proved to be a modification of that originally described by Kvarstein (1969) in which whole blood is pumped at a fixed rate through a fixed weight of glass beads in a column. Using this technic, there was significant variation from one to another subject, but the mean of differences between duplicates from the same subject differed only by a mean of 3-4 %. Further indirect evidence that microtubule function may play a significant role in neutrophil adhesion was obtained. Vincristine, a chemical known to interfere with microtubule function, proved to reduce neutrophil adhesion while heavy water, a substance known to stabilize microtubules, increased neutrophil adherence. In confirmation of the work of others, adrenal glucocorticosteroids were found to have no effect when incubated in vitro with whole blood, but when neutrophils were taken from normal subjects who had been treated with steroids 4 h before, there was a distinct decrease in neutrophil adherence. Bacterial endotoxin incubated with whole blood in vitro had no effect at small doses, but at large in vitro doses produced an increase in adhesion. Conversely, when neutrophils were obtained from normal subjects treated with bacterial endotoxin a decrease in neutrophil adherence was observed. This latter effect, decrease in neutrophil adhesion in subjects treated with bacterial endotoxin, seems unlikely to be associated with any in vivo kinetic changes known to be produced by bacterial endotoxin. Consequently, we would wonder if the decreased neutrophil adhesion observed after both steroids and endotoxin docs not simply reflect a decreased adherence of cells freshly released from the bone marrow to the blood as compared to those which have been in the blood for some time.