Restricted subpopulations of DNA antibodies in kidneys of mice with systemic lupus. Comparison of antibodies in serum and renal eluates.

Sera from MRL/1, BXSB, and NZB/NZW mice, which develop IgG antibodies to DNA and glomerular deposits of DNA-antiDNA immune complexes, were studied by isoelectric focusing. A large array of IgG antibodies with isoelectric points ranging from pH 5.5--9.0 were found to bind double-stranded DNA. Antibodies with isoelectric points from 8.0--8.5 were significantly more frequent than antibodies focusing in all other pH ranges. In contrast, glomerular eluates from MRL/1 and NZB/NZW mice contained a restricted number of DNA-binding bands, all of which focused at pH 8.0--9.0. Anti-DNA with isoelectric points from pH 8.0--9.0 may be more pathogenic for the kidney than other subpopulations.