Measurement of circulating immune complexes in human sera by enzyme immunoassay

Two methods, based on enzyme immunoassay, are described for the detection and quantitation of circulating immune complexes (CIC) in human sera. Aggregated human gamma globulin (AHG) or immune complexes in human sera are bound to complement receptors on Raji cells or to Clq adsorbed on to the plastic surface of microtitre plates. The bound complexes are subsequently detected using peroxidase-conjugated anti-human immunoglobulin antisera. The assays offer a benefit over previously described assays in that they use cheap, commercially available antisera and enable the detection of immune complexes composed of varying immunoglobulin classes.