An investigation of leukocyte function and phagocytosis of immune complexes in patients with rheumatoid arthritis.
By means of the nitroblue tetra-zolium (NBT)-dye test, patients with chronic rheumatoid arthritis (RA) were studied. It was found that patients with rheumatoid factor (RF) in their sera displayed higher levels of NBT-dye reduction than those without RF did. In RF(+) serum, the authors observed a remarkable activation of NBT-dye reduction in phagocytosis of immune complexes and 1gG-coated latex particles. A fluorescent antibody technique and immuno-electron microscopy showed an increased phagocytosis of gamma-globulin in peripheral polymorphonuclear leukocytes (PMN) from patients with activated levels of NBT-dye reduction. From these results, it is likely that PMNs from patients, particularly from those possessing high values of NBT-dye reduction, displayed the activated levels of phagocytosing autologous globulin.