In vitro methods for detection of circulating immune complexes.

The possible pathologic consequences of the presence of circulating immune complexes in certain disease states has caused considerable attention to be given to the development of laboratory procedures capable of quantitatively measuring the presence of immune complexes in serum. Many assays are available which utilize differing properties of immune complexes for their detection. Examples of assays which depend on different biologic properties of circulating immune complexes are presented and discussed. Included are the Raji cell assay, Clq binding assay, inhibition of rheumatoid agglutination, and nephelometric assays for determination of circulating immune complexes.