A solid-phase assay for circulating immune complexes using monoclonal rheumatoid factors and peroxidase-linked protein A.
A solid-phase monoclonal rheumatoid factor (mRF) assay for circulating immune complexes (IC) is described. Microtiter plates are coated with mRF, serum diluted 1 : 40 is added, and complexed IgG is detected with protein A coupled to peroxidase. Selective binding was obtained with aggregated human gamma-globulin and soluble IC prepared in vitro. Sucrose density gradient ultracentrifugation studies indicate that mRF binds intermediate-size IC (between 7S and 19S). Abnormal levels of IC were found in 78% of sera from patients with rheumatoid arthritis, 67% with systemic lupus erythematosus, and 87% with subacute bacterial endocarditis.
D000936:Antigen-Antibody Complex; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001665:Binding Sites; D001793:Blood Preservation; D002499:Centrifugation, Density Gradient; D002999:Clone Cells / Q000276:immunology; D004698:Endocarditis, Subacute Bacterial / Q000276:immunology; D006433:Hemocyanins / Q000276:immunology; D006735:Horseradish Peroxidase; D006801:Humans; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D012217:Rheumatoid Factor / Q000276:immunology* / Q000378:metabolism; D013205:Staphylococcal Protein A / Q000378:metabolism*
D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D013205:Staphylococcal Protein A; D012217:Rheumatoid Factor; D006433:Hemocyanins; D006735:Horseradish Peroxidase