Modification of Human Neutrophil Response to Endotoxin with Polymyxin B Sulfate

Polymyxin B sulfate has been reported to neutralize endotoxin toxicity in animals. In a study of the applicability of this antibiotic to the treatment of patients with endotoxemia, human neutrophils were examined in vivo and in vitro, and the effect of polymyxin B on white blood cells stimulated with endotoxin and those not stimulated with endotoxin was delineated. Absolute neutrophil counts of normal patients receiving typhoid vaccine subcutaneously, both alone and after mixing with polymyxin B, were followed serially during 8-hr periods. The characteristic neutrophilia observed when vaccine was administered alone was reduced by use of polymyxin B sulfate. In in vitro studies human neutrophils stimulated with endotoxin had an increased reduction of nitroblue tetrazolium dye. This stimulatory effect of endotoxin on the nitroblue tetrazolium response of the neutrophil was diminished or abolished by polymyxin B. These data suggest that endotoxin-induced changes in neutrophils of humans can be prevented under certain circumstances with polymyxin B sulfate.