A double antibody solid phase assay for DNA autoantibodies for clinical use.
DNA antoantibodies in serum will bind to antigen-coated polystyrene tubes and can be detected by radiolabelled anti-immunoglobulin. The method is quantitative, gives information on the antibody class and is not readily subject to interference by factors such as the size of the DNA, minor contamination of double-stranded with single-stranded DNA and the presence of materials which can combine "non-specifically" with the antigen. Double-stranded DNA gave good discrimination between SLE and rheumatoid arthritis but with single-stranded preparations approximately 40% of the RA patients showed elevated antibody values. Individual results obtained with the two antigens were compared and correlated with the Farr test and ANA titres. Surprisingly, a proportion of the SLE sera gave high background binding to  tubes coated with gelatine.
D000974:Antibodies, Antinuclear; D000941:Antigens; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis*; D003095:Collagen Diseases / Q000276:immunology; D004247:DNA / Q000276:immunology*; D004277:DNA, Single-Stranded / Q000276:immunology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D011863:Radioimmunoassay / Q000379:methods
D000974:Antibodies, Antinuclear; D000941:Antigens; D001323:Autoantibodies; D004277:DNA, Single-Stranded; D004247:DNA