[Binding of complement by anti-native desoxyribonucleic acid antibodies in systemic lupus erythematosus]

Antibodies directed against double-stranded (native) desoxyribonucleic acid (dsDNA) were detected by the immunofluorescence technique on Crithidia luciliae in 38 out of 58 patients with systemic lupus erythematosus (SLE) and in 22 out of 296 controls with autoimmune diseases. The SLE patients had high titers of anti-dsDNA antibodies which belonged at least to the IgG class and fixed the complement in 20 out of 38 cases. These complement-fixing antibodies differed from the others in their greater activity, as evaluated by C3 levels, and in their association with a high incidence of renal lesions.