Clonotypes of anti-DNA antibodies expressing specific idiotypes in immune complexes of patients with active lupus nephritis.
IEF, using 6 M urea, provides a unique opportunity to analyze the spectrotypes of antibodies in immune complexes (IC) in vivo. Using this technique, we have analyzed the clonotypes of anti-DNA antibodies expressing specific Id in the circulating IC of patients with active lupus nephritis. Serum anti-ssDNA and anti-dsDNA antibodies showed heterogeneous spectrotypes. The antibodies isolated from circulating IC had a restricted clonotype and a neutral charge and were directed mainly to ssDNA and, to a lesser extent, to dsDNA. These samples failed to form complexes with DNA when they were subjected to absorption to a DNA-coupled Sepharose column. Anti-DNA antibodies expressed specific Id, termed O-81 or NE-1, which were detected only in the IC of patients with active lupus nephritis. Anti-DNA clonotypes, including O-81 and NE-1 idiotypes, were also found in the eluates of renal glomeruli of lupus patients. These results indicate that subpopulations of anti-DNA antibodies in circulating IC are limited, and may play an important role in the pathogenesis of lupus nephritis.
Muryoi
T
T
Second Department of Internal Medicine, Tohoku University School of Medicine, Seiryocho, Japan.
Sasaki
T
T
Hatakeyama
A
A
Shibata
S
S
Suzuki
M
M
Seino
J
J
Yoshinaga
K
K
D000974:Antibodies, Antinuclear / Q000276:immunology*; D000936:Antigen-Antibody Complex / Q000276:immunology*; D002999:Clone Cells; D006801:Humans; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D007525:Isoelectric Focusing; D007668:Kidney / Q000276:immunology; D008181:Lupus Nephritis / Q000276:immunology*
D000974:Antibodies, Antinuclear; D000936:Antigen-Antibody Complex; D007130:Immunoglobulin Idiotypes