Benign monoclonal gammopathy with IgG anti-DNA, anti-Sm and anti-F(ab')2 activity.
OBJECTIVE
To study anti-DNA idiotypic markers and anti-DNA activity in human monoclonal immunoglobulin proteins.


METHODS
Seventy human IgG M-components intentionally selected for cationic electrophoretic characteristics were studied for F4 and 31 anti-DNA idiotypic markers and anti-DNA as well as anti-F(ab')2 antibody activity.


RESULTS
Eight of 70 M-components showed significant anti-DNA activity. In two both anti-DNA and anti-F(ab')2 activity occurred together. One IgG-2 kappa M-component showed extremely high anti-ds DNA, anti-Sm, anti-F(ab')2 and anti-Sm/ RNP ELISA activity. Cross inhibition studies showed that each reactive antigen inhibited the other. N-terminal V-region sequencing showed the VH3, VK3 subgroup. Anti-idiotypic rabbit antibody produced against this M-component showed strong reactivity with affinity purified IgG anti-DNA and anti-F(ab')2 from most SLE patients and normal subjects.


CONCLUSIONS
Monoclonal human immunoglobulins may contain multiple autoantibody specificities including anti-DNA; anti-Sm, anti-Sm/RNP, and anti-F(ab')2. Many antibodies with these specificities share common V-region antigens. Such relationships could contribute to idiotypic immune regulation and control.
Williams
R C
RC
Department of Medicine, University of Florida Health Sciences Center, Gainesville 32610, USA.
Malone
C C
CC
Silvestris
F
F
Nickerson
K G
KG
D000368:Aged; D000818:Animals; D000974:Antibodies, Antinuclear / Q000032:analysis*; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D004247:DNA / Q000276:immunology*; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology*; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology*; D007130:Immunoglobulin Idiotypes / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D010265:Paraproteinemias / Q000276:immunology*; D011817:Rabbits; D012016:Reference Values; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D001324:Autoantigens; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D007130:Immunoglobulin Idiotypes; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins; D004247:DNA