Quantitative nitro blue tetrazolium test in febrile patients. Correlation with diagnosis and bacterial activity of leukocytes.

The quantitative nitro blue tetrazolium (NBT) test did not show increased NBT reduction in bacterial infections as frequently as has been reported with the qualitative NBT test in untreated infections. Lower than normal values were seen in septic shock and bacterial endocarditis, and normal results were seen in most other bacterial infections. Increased NBT reduction was seen with reticulum cell sarcoma, Hodgkin disease, postoperative wound infections, and upper respiratory tract infections. Thus, the quantitative NBT was of little use in diagnosis of acute infections. The correlation between quantitative tests and tests of bactericidal capacity of leukocytes was poor. These data suggest that NBT reduction and bactericidal activity are dissociative events within phagocytes. Patients with low NBT results usually had bactericidal activity within normal limits.