Granulocyte function in bacterial infections in man.

The reduction of nitroblue tetrazolium (NBT) dye and the phagocytic and bactericidal activities of neutrophil granulocytes from 141 patients with bacterial infections and 141 controls have been examined and related to granulocyte morphology. In 115 patients (82 per cent), the NBT reduction capacity was higher than in any control. Vacuolization of the cytoplasm and/or toxic granulation of the neutrophils were demonstrated more often in patients with high than low NBT reduction capacity. In 49 patients (35 per cent), the bactericidal activity of the neutrophils was lower than in any control. Thirty-eight patients (78 per cent) with impaired bactericidal activity had 25 per cent or more peripheral juvenile neutrophils as compared with only 12 (13 per cent) out of 92 patients with normal activity. Vacuolization of the cytoplasm and/or toxic granulation of the neutrophils were demonstrated in 28 patients (57 per cent) in whom the granulocyte function was reduced and in 26 patients (28 per cent) in whom function was normal. Within wide limits, the NBT reduction capacity increased with diminishing bactericidal activity of the neutrophils. Eighteen patients died of infection; 12 had reduced bactericidal activity. Defects in neutrophil granulocyte function caused by bacterial infection may contribute to a fatal outcome of the disease.