Detection of immune complexes in polymorphonuclear leukocytes by double immunofluorescence in patients with IgA nephropathy

Abstract

The amounts of cytoplasmic inclusion bodies in peripheral blood polymorphonuclear cells (PMN) were determined in patients with IgA nephropathy and other glomerular diseases to elucidate whether or not IgA-dominant immune complexes were phagocytized by PMN in these patients. Fifteen patients with IgA nephropathy, 8 patients with other glomerular diseases, and 10 healthy adults were examined. The amounts of cytoplasmic inclusion bodies were measured by a double immunofluorescence technique. It was demonstrated that the percentages of IgA with C3 and IgA without C3 cytoplasmic inclusion bodies were significantly increased in patients with IgA nephropathy compared with those obtained in other glomerular diseases and healthy adults. There was a significant correlation between the levels of serum IgA and the percentage of IgA with C3 cytoplasmic inclusion bodies in PMN from patients with IgA nephropathy. It was suggested that IgA-dominant immune complexes are phagocytized by peripheral blood PMN in patients with IgA nephropathy.