Cold-reacting antinuclear factor in sera from patients with IgA nephropathy.

ANF was determined in sera from patients with IgA nephropathy to evaluate the autoimmune nature of this disorder. Sera from 33 patients with IgA nephropathy were assayed for ANF by the FANA technique at 37 degrees and 4 degrees C as well as by a hemagglutination technique. In addition, sera from five patients with lupus nephritis and six patients with idiopathic membranous nephropathy were examined. Thirty healthy adults served as controls. Cold-reacting ANF, which was detected predominantly in the class of IgM, was observed in 81.8% of patients with IgA nephropathy. The nuclear staining pattern was "speckled." Sera from healthy adults did not show any positive signs of ANF, whereas those from patients with lupus nephritis demonstrated "shaggy" pattern of ANF. It is suggested that some autoimmune mechanisms may be involved in the development of IgA nephropathy.