Radioassay of soluble immune complexes using their uptake by macrophage Fc receptors.
Sera from patients were tested for the presence of soluble immune complexes (IC) by a method based on the observation that IC inhibit uptake of aggregated IgG by the Fc receptors of macrophages. From the saturation curve of macrophages with 125I-labelled aggregates the optimal inhibitory effect of a measured amount of IC was determined. This radioassay is highly sensitive, being capable of detecting 20 ng of IC, is reproducible and covers a wide range of measurement (20-2000 ng).
D000936:Antigen-Antibody Complex; D001666:Binding Sites, Antibody; D003165:Complement System Proteins; D006801:Humans; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D011863:Radioimmunoassay / Q000379:methods
D000936:Antigen-Antibody Complex; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D003165:Complement System Proteins