[Flow cytometric measurement of NBT-reducing activity in peripheral leukocytes applying THMS H.1TM]

Nitroblue tetrazolium (NBT) is reduced to a blue dye (blue formazan, gamma max 560 nm) by superoxide (O2-.) released from phagocytes upon phorbol myristate acetate-stimulation, resulting in the blue dye-deposition on the cell membrane. Thus, we tried to develop a semi-quantification method for determining the NBT-reducing activity in the peripheral leukocytes (NBT-staining intensity -SI- and its distribution in the cell) by flow cytometry. The SI (mean +/- SD) was 28.4 +/- 2.2 (n = 30) in normal subjects and 0.9 in a patient with chronic granulomatous disease, whereas it was 37.6 in a patient with malaria. In addition, patients with myelodysplastic syndrome showed values of 29.2 +/- 7.0 (n = 11), while a patient with partial monosomy of chromosome No. 7 had an SI of 10.8. The present assay of NBT-reducing activity in phagocytes may be useful for screening of peripheral leukocyte function.