Profiling of circulating immune complexes by high performance liquid affinity chromatography (HPLAC) on a protein...

Protein A, a cell wall protein found in bacterial strains of Staphylococcus aureus, has been extensively used in the analysis and purification of immunoglobulins and immune complexes. By binding protein A to microparticulate silica (high performance liquid affinity chromatography, HPLAC), a rapid and efficient chromatographic system was obtained for the separation and analysis of circulating immune complexes. The method was applied to the separation of artificial immune complexes as well as to plasma samples from patients with immune complex associated diseases such as SLE and RA. It was possible to distinguish certain subpopulations of circulating immune complexes by performing pH gradients on the protein A silica HPLAC column.