HIGHLY CATIONIC ANTI-DNA ANTIBODIES IN PATIENTS WITH LUPUS NEPHRITIS ANALYZED BY 2-DIMENSIONAL ELECTROPHORESIS AND IMMUNOBLOTTING

The relationship between chemical properties of anti-DNA antibodies (A bs) and lupus nephritis was investigated. The anti-DNA Abs in sera fro m systemic lupus erythematosus (SLE) patients were separated by two-di mensional electrophoresis (2-DE) and immunoblotting with goat anti-hum an IgG Abs. Highly cationic anti-DNA Abs were detected in deoxyribonuc lease I (DNase I)-treated sera from patients with lupus nephritis (in 8 of 9 cases) but not in the sera from SLE patients without nephritis (in 0 of 9 cases), normal subjects, or patients with other renal disea ses (in 0 of 7 cases). The mean titers of anti-dsDNA Abs in patients w ith lupus nephritis were not significantly different from those in SLE patients without nephritis. The highly cationic anti-DNA Abs in the s era disappeared after incubation with heparin-Sepharose. These results suggest that highly cationic anti-DNA Abs are specific for lupus neph ritis and may be involved in development of lupus nephritis via the bi nding to glycosaminoglycans on the endothelial cell surface.