Oxidative metabolism of polymorphonuclear leukocytes (PMN) in patients with IgA nephropathy.

The production of hydrogen peroxide (H2O2) by neutrophilic polymorphonuclear leukocytes (PMN) after stimulation and the infiltration of PMN in glomeruli were determined in 20 patients with primary IgA nephropathy. The H2O2 production of PMN after the stimulation was measured with a spectrophotometer using horseradish peroxidase as substrate. The results were as follows: 1) when PMN were pretreated with cytochalasin B, H2O2 production after stimulation with heat-aggregated IgG (IgG) or serum-treated zymosan (STZ) was significantly higher in patients with IgA nephropathy than in controls, and 2) there was an increased amount of PMN localized in glomeruli in patients with IgA nephropathy using immunofluorescence of monoclonal anti-PMN antibody. It appeared that the increased renal infiltration of PMN which have a high potential for production of reactive oxygen species might induce the glomerular injuries in patients with IgA nephropathy.