Nitroblue‐tetrazolium Staining of Human Neutrophil Granulocytes

Bacteria‐free filtrates from Pseudomonas aeruginosa cultures were added to heparinized blood from 10 patients with multiple Pseudomonas precipitins and from 11 patients without such precipitins before carrying out a nitroblue‐tetrazolium (NBT) test. Increased NBT staining could be induced in neutrophils from all of the patients with demonstrable Pseudomonas precipitins but only in 3 of the patients without precipitins. This difference was found to be statistically significant. Using patients' plasma but leucocytes from a normal control person it was found that this difference was dependent upon the origin of plasma but independent of the origin of leucocytes. These findings indicate that increased NBT staining of neutrophils induced by bacterial products in vitro is in part dependent upon antigen antibody interaction.