SU UN NBT TEST DIFFERENZIALE NELLA DIAGNOSTICA DELLE MALATTIE INFETTIVE

A differential NBT (nitroblue tetrazolium) qualitative test was separately performed on neutrophil granulocytes and monocytes in a number of healthy controls and in bacterial, mycotic, protozoal and viral infections. Whereas the test on both cell types was negative in healthy controls (frequency of cells spontaneously reducing the dye by less than 8%), increased spontaneous reduction at levels of test positivity (>8%) constituted a more constant feature of monocytes than of granulocytes in the infectious conditions. This was particularly true of viral infections where the test was positive on monocytes even when negative on granulocytes. These phenomena, together with the particularly strong positivity of the NBT test on monocytes of patients infected with pathogens (brucellae, salmonellae, toxoplasma) behaving as intracellular parasites, probably reflect undefined kinds of interaction between the infecting agents and mononuclear phagocytes.