Demonstration of the neutrophil granulocyte functional capacity in silicosis, using the NBT test.

The functional capacity of neutrophils was studied using the NBT test in 68 patients with silicosis in various evolutive stages, comparatively with a group of 35 controls. The NBT test showed an initial increase of nonspecific cellular reactivity which decreased as the disease evolved. The results in the control group showed 9 +/- 5% NBT positive neutrophils. The highest proportion of NBT positive neutrophils (17.6 +/- 2.3, p < or = 0.05) was found in stage I of the disease and then decreased gradually with the evolution of the disease. The proportion of NBT positive neutrophils may be considered as a biochemical marker of neutrophil functionality.