Evaluation of the usefulness of nitroblue tetrazolium reduction test (NBT test) for detection of bacterial infection in cancer patients.

False positivity of the NBT test in neoplastic diseases described by some authose may be a limitation in the use of the test for infection screening in cancer patients. For explaining this problem studies were performed in a group of 30 patients with various untreated malignancies without infection and in 20 of these with bacteriologically confirmed infections. The obtained results were compared with those in groups of normal persons without and with infection. Slightly modified Park method for spontaneous and stimulated NBT test was used. No significant differences between patients of both groups without infection were found. The increase in positivity of the test in presence of infection was lower in cancer patients than in normal subjects, however, it was non-significant. We did not observe any false-positive results in our patients, though one case of false negativity in myeloma is described separately. It is concluded that neoplastic disease does not cause, as such positivity of the NBT test. Because of similar response of NBT test to presence of infection, the NBT test is recognized as very useful for infection screening in cancer patients similarly as in normal persons.