title: Detection of DNA-bound immunoglobulins in patients with lupus nephritis, using monoclonal anti-DNA antibody.
abstract: In order to investigate the relationship between renal histopathology and the characteristics of circulating immune complexes (CICs) in patients with lupus nephritis (LN), we measured the sizes of CICs, DNA-bound immunoglobulins in patients with systemic lupus erythematosus (SLE) and different histopathological forms of nephritis. Sera were obtained from nine patients: four with diffuse proliferative LN (DPLN), four with membranous LN (MLN), and one with mesangial LN, who fulfilled the criteria of the American Rheumatism Association for SLE. The DNA-bound immunoglobulins were measured by ELISA, in which ELISA plates were coated with mouse monoclonal anti-DNA antibodies. The sizes of CICs were analysed by sucrose density gradient ultracentrifugation. Large (larger than 19S), intermediate (19-7S) and small (nearly 7S) sized DNA-bound immunoglobulins (high peaks of IgG and IgA, but low IgM peaks) were found in the patients with DPLN. By contrast, in patients with MLN, the sizes of ICs; DNA-bound IgG, IgA were in general slightly larger than 7S. In one patient with DPLN, at the onset, various sized DNA-bound IgG, IgA and IgM were found. After the methylprednisolone pulse therapy, CICs became smaller and gradually disappeared. We conclude that the characteristics of DNA-anti-DNA IgG, IgA complexes may determine the localization of ICs in the glomeruli and suggest that CICs play an important role in the pathogenesis of LN.
authors.affiliation: Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Koyama
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: N
authors.initials: N
authors.lastname: Yamaguchi
authors.forename: M
authors.initials: M
authors.lastname: Narita
mesh_terms: D000974:Antibodies, Antinuclear / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000032:analysis / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology*; D015922:Complement C1q / Q000378:metabolism; D004247:DNA / Q000032:analysis / Q000276:immunology*; D006801:Humans; D007678:Kidney Glomerulus / Q000276:immunology; D008181:Lupus Nephritis / Q000276:immunology*; D008775:Methylprednisolone / Q000494:pharmacology
chemical_list: D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D015922:Complement C1q; D004247:DNA; D008775:Methylprednisolone